The Basic Principles of External Skeletal Fixation Using the Ilizarov Device

The Basic Principles of External Fixation Using the Ilizarov Device Leonid N. Solomin Leonid N. Solomin The Basic Pri...

Author: Leonid Solomin

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The Basic Principles of External Fixation Using the Ilizarov Device Leonid N. Solomin

Leonid N. Solomin

The Basic Principles of External Fixation Using the Ilizarov Device

Leonid N. Solomin R. R. Vreden Russian Research Institute of Traumatology and Orthopaedics 8 Baykova Str. Saint Petersburg, Russia, 195427 E-mail: solomin [email protected]

This book is intended for those, who got connected with the External Fixation and still have a desire to learn it in such a way as to improve it. Thanks are due to Prof. J. Tracy Watson, Djoldas Kuldjanov, MD, and Dr. Evgeny Tchekashkine for translating and editing some chapters of this book.

Original title:

Osnovy qreskostnogo osteosinteza apparatom G. A. Ilizarova © 2005 “Morsar AV”, Saint Petersburg, 2005 Graphics: E. Chukhonina, L. Arsentjev, K. Guzenko

Library of Congress Control Number: 2007937660 ISBN 978-88-470-0512-9 Springer Milan Berlin Heidelberg New York e-ISBN 978-88-470-0513-6 Springer is a part of Springer Science + Business Media springer.com © Springer-Verlag Italia 2008 This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, re-use of illustrations, recitation, broadcasting, reproduction on microfilms or in other ways, and storage in data banks. Duplication of this publication or parts thereof is only permitted under the provisions of the Italian Copyright Law in its current version, and permission for use must always be obtained from Springer. Violations are liable for prosecution under the Italian Copyright Law. The use of general descriptive names, registered names, trademarks, etc., in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. Product liability: The publisher cannot guarantee the accuracy of any information about dosage and application contained in this book. In every individual case the user must check such information by consulting the relevant literature. Cover design: Simona Colombo, Milan, Italy Typesetting with LATEX: PTP-Berlin Protago-TEX-Production GmbH, Germany. www.ptp-berlin.eu Printer: Grafiche Porpora, Cernusco/Naviglio, Italy Printed in Italy Springer-Verlag Italia S.r.l.,Via Decembrio 28, I-20137 Milan

To the memory of my parents

Forewords

This book is the first comprehensive text on the Ilizarov method to come from Russia since Professor Ilizarov passed away in 1992.The text covers both acute traumatic reconstruction with the Ilizarov method and orthopaedic reconstruction with the Ilizarov techniques. The authors unique method of cross-sectional anatomy evaluation improves the safety of pin and wire insertion. The text is well illustrated for ease of understanding and numerous case examples are presented demonstrating the results of different treatment methods. Dr. Solomin helps the reader advance along the learning curve of these complicated methods while learning from the author’s extensive experience and avoiding the pitfalls of treatment. Dr. Solomin’s work is a testament to the Ilizarov method’s versatility and utility in the first generation after Professor Ilizarov’s death.This book will serve as a new foundation for the next generation of orthopaedic surgeons interested in limb reconstruction using circular external fixation. Dror Paley, MD, FRCSC Director, Rubin Institute for Advanced Orthopedics Co-Director, International Center for Limb Lengthening Sinai Hospital of Baltimore Balitmore, Maryland, USA

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Forewords

Dr. Solomin’s monograph “Basic principles of external fixation using the Ilizarov device” is one of a number of domestic and foreign texts testifying to the steady growth of interest from orthopaedic surgeons in the problems of achieving a reliable osteosynthesis and in finding a way to really control the bone regeneration process. A convenient classification of external fixation devices, unification of the terminology used, a description of the equipment (some of which is original), and a presentation of the biomechanical basis of external fixation will be useful in practice not only for beginners, but also for those who have some experience of the use of the Ilizarov apparatus. In the manual the reader will find not only an analysis of the basis of external fixation, but also the author’s original approach in this field. The manual includes an atlas of transosseous element insertion. The concepts of “safe positions”, where there are no main vessels and nerves, and “reference positions”, that are used to decrease pin-induced joint stiffness and pin-tract infections, are described. The coordinates derived from the “Method for the Unified Designation of External Fixation” allow data to be precisely transferred to the operation table. Certainly,no book can include all possible clinical situations in orthopaedic practice.Nevertheless,this manual is different from others in being easy to read. Consequently the execution of each method of external fixation can be readily grasped. Furthermore, as stated above, the perfectly prepared illustrations will be of significant benefit to the orthopaedic surgeon. Prof. Vladimir I. Shevtsov Director, Russian Ilizarov Scientific Center “Restorative Traumatology and Orthopaedics” Kurgan, Russia

Forewords

IX

I am pleased to present this book to experts on external fixation and to those who are taking only their first steps in this field. Having been engaged in the development of external fixation for a long time, I am certain that its potential in rehabilitative treatment is practically unlimited. However, external fixation is highly technical and it is necessary to have a full command of it! A perfunctory knowledge of the method together with its negligent implementation will not satisfy the aspirations of the doctor, will bring suffering to the patient, and will throw a shadow on the authors who are responsible for the method. I regret that the “Method for the Unified Designation of External Fixation” is only now becoming the standard language of orthopaedic surgeons. If it had been developed and introduced earlier, it would have been possible to avoid many of the criticisms (sometimes justified) of the training in the method resulting from “individual” perceptions of the information in articles, instructional lectures, and manuals. It is necessary to note, that the device assemblies for combined (hybrid) external fixation, developed by the author, complement the original Ilizarov devices, the efficiency of which has been confirmed over decades. The clever design, the high-quality illustrations, the wide range of pathological conditions considered for application of external fixation, and the style of presentation of the material are great advantages of this manual. I am sure that it will prove to be of great interest to orthopaedic surgeons in many different countries. Prof. Viktor K. Kalnberz Riga, Latvia

Table of Contents

Contributors 1

General Aspects of External Fixation 1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2 Historical Background and Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.3 Advantages and Disadvantages, Indications and Contraindications . . . . . . . . . . . . . . . . 1.4 Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5 General Terms for External Fixation Constructs . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.6 Biomechanical Principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.6.1 Relationship between the Transosseous Elements and the Surrounding Tissues . . . 1.6.2 Control of Bone Fragment Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.6.2.1 Moving the External Supports with the Transosseous Modules Fixing the Bone Fragments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.6.2.2 Moving the Transosseous Elements Relative to the External Supports; External Supports and Modules Remain Immobile . . . . . . . . . . . . . . 1.6.3 Control of Bone Fragment Rigidity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.6.3.1 Material from which the Elements are Manufactured . . . . . . . . . . . . . 1.6.3.2 Number of Transosseous Elements . . . . . . . . . . . . . . . . . . . . . . . . 1.6.3.3 Diameter and Type of Transosseous Elements . . . . . . . . . . . . . . . . . 1.6.3.4 Wire Tension . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.6.3.5 Levels of Transosseous Element Insertion . . . . . . . . . . . . . . . . . . . . 1.6.3.6 Plane of Orientation of the Transosseous Elements . . . . . . . . . . . . . . 1.6.3.7 Distance from the Bone to the External Support . . . . . . . . . . . . . . . 1.6.3.8 External Support Geometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.6.3.9 Number of Connecting Rods . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.7 Internal Contradictions in External Fixation: Combined External Fixation (CEF) . . . . . . 1.7.1 Method for the Unified Designation of External Fixation (MUDEF) . . . . . . . . . . 1.7.2 Use of Different Types of External Support and Transosseous Elements . . . . . . . 1.7.3 Reference Positions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.7.4 Minimum Number of External Supports and Transosseous Elements . . . . . . . . . 1.7.5 Module Transformation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.7.6 Computer Navigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.8 Method for the Unified Designation of External Fixation (MUDEF) . . . . . . . . . . . . . . . 1.8.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.8.2 Symbols Used . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.8.3 Coordinates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.8.4 Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.8.5 Positions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.8.6 Designation of Transosseous Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.8.7 Designation of K-wires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.8.8 Designation of Half-Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Table of Contents

1.8.9 Designation of the External Support Frame . . . . . . . . . . . . . . . . . . . . . . . . 1.8.10 Designation of the Whole Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.8.11 Additional Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.9 Atlas for Insertion of Transosseous Element Reference Positions . . . . . . . . . . . . . . . . . 1.9.1 Upper arm (L. N. Solomin, R. E. Inyushin) . . . . . . . . . . . . . . . . . . . . . . . . . . 1.9.2 Ulna (L. N. Solomin, P. N. Kulesh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.9.2.1 Mid-position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.9.2.2 Supination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.9.2.3 Pronation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.9.3 Radius (L. N. Solomin, P. N. Kulesh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.9.3.1 Mid-position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.9.3.2 Supination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.9.3.3 Pronation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.9.4 Femur (L. N. Solomin, M.V. Andrianov) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.9.5 Tibia (L. N. Solomin, D.A. Mykalo) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.10 Preoperative Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.11 Principles of Frame Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.11.1 Identification of Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.11.2 Identification of the Optimal Levels for Locating the External Supports . . . . . . . 1.11.3 Identification of the Possible Transosseous Elements on the Basis of Safe Positions and Reference Positions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.11.4 Identification of Transosseous Elements Best Suited to the Particular Clinical Situation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.11.5 Selection of the Type and Size of External Support for Every Level of Transosseous Element Placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.11.6 Marking of the Selected Levels and Positions on the Segment for Transosseous Element Placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.11.7 Transosseous Element Insertion and External Support Installation . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Suggested Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Specific Aspects of External Fixation 2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . 2.2 Fractures of the Humerus . . . . . . . . . . . . . . . 2.2.1 Proximal Humerus (11-) . . . . . . . . . . . 2.2.2 Diaphyseal Fractures (12-) . . . . . . . . . . 2.2.2.1 Proximal Third . . . . . . . . . . . 2.2.2.2 Middle Third . . . . . . . . . . . . 2.2.2.3 Distal Third . . . . . . . . . . . . . 2.2.2.4 Radial Nerve Injury . . . . . . . . 2.2.3 Distal Humerus (13-) . . . . . . . . . . . . . 2.3 Fractures of the Forearm . . . . . . . . . . . . . . . . 2.3.1 Proximal Forearm (21-) . . . . . . . . . . . . 2.3.2 Diaphyseal Fractures (22-) . . . . . . . . . . 2.3.2.1 Ulnar Diaphysis . . . . . . . . . . 2.3.2.2 Radial Diaphysis . . . . . . . . . . 2.3.2.3 Diaphysis of the Radius and Ulna 2.3.3 Distal Forearm (23-) . . . . . . . . . . . . . . 2.4 Fractures of the Femur . . . . . . . . . . . . . . . . . 2.4.1 Proximal Femur (31-) . . . . . . . . . . . . . 2.4.2 Diaphyseal Fractures (32-) . . . . . . . . . . 2.4.2.1 Proximal Third . . . . . . . . . . . 2.4.2.2 Middle Third . . . . . . . . . . . .

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Table of Contents

2.5

2.6 2.7 2.8

2.9

2.10 2.11

2.12

2.13

2.4.2.3 Distal Third . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.4.3 Distal Femur (33-) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.4.4 Patella (91.1-) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fractures of the Tibia and Fibula . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5.1 Proximal Tibia and Fibula (41-) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5.2 Diaphyseal Fractures (42-) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5.2.1 Proximal Third . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5.2.2 Middle Third . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5.2.3 Distal Third . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5.3 Distal Tibia and Fibula (43-) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5.4 Ankle Injuries (44-) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5.5 Chronic Ankle Injuries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Compound Fractures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Malunited Fractures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Basic Principles of Correction of Long-Bone Deformities . . . . . . . . . . . . . . . . . . . . . . 2.8.1 Inequality in Length of the Extremities . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.8.2 Angular Deformities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.8.3 Rotational Deformities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.8.4 Technical Tips and Tricks for the Humerus and Forearm . . . . . . . . . . . . . . . . . Aesthetic Correction of the Lower Extremities (A.A. Artemiev, O.A. Kaplunov, L. N. Solomin) 2.9.1 Shape of the Legs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.9.2 True Bow-Legs (Varus) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.9.3 Volume and Contour of the Lower Legs . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.9.4 Growth and Length of the Lower Extremities . . . . . . . . . . . . . . . . . . . . . . . . 2.9.5 Complications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Nonunions, Pseudoarthroses and Long-Bone Defects . . . . . . . . . . . . . . . . . . . . . . . . . Combined Strained Fixation of the Long Bones . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.11.1 Equipment for CSF and Principles of Application . . . . . . . . . . . . . . . . . . . . . . 2.11.2 Humerus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.11.3 Femur . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.11.4 Tibia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.11.5 Forearm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.11.5.1 Ulna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.11.5.2 Radius . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.11.5.3 Both Forearm Bones (Combinative Fixation) . . . . . . . . . . . . . . . . . . . 2.11.6 Clavicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.11.6.1 External Fixation of the Clavicle . . . . . . . . . . . . . . . . . . . . . . . . . . 2.11.7 Postoperative Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pelvic Injuries (A.V. Runkov, L. N. Solomin) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.12.1 Insertion of Transosseous Elements into the Pelvic Bones . . . . . . . . . . . . . . . . . 2.12.2 Principles of Assembly of External Devices for Fixation of Pelvic Injuries . . . . . . . 2.12.3 Surgical Technique . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.12.4 Osteosynthesis in Stable and Partially Stable Pelvic Injuries . . . . . . . . . . . . . . . . 2.12.5 Osteosynthesis in Vertical Unstable Pelvic Injuries . . . . . . . . . . . . . . . . . . . . . 2.12.6 External Fixation of Fractures of the Acetabulum . . . . . . . . . . . . . . . . . . . . . . 2.12.7 Postoperative Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.12.8 External Fixation of Malunited Pelvic Fractures . . . . . . . . . . . . . . . . . . . . . . . Foot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.13.1 Forefoot Injuries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.13.2 Midfoot Injuries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.13.3 Hindfoot Injuries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.13.3.1 External Fixation of Talus Fractures . . . . . . . . . . . . . . . . . . . . . . . . 2.13.3.2 External Fixation of Calcaneal Fractures . . . . . . . . . . . . . . . . . . . . .

XIII

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165 168 171 172 175 178 178 179 179 183 184 188 190 198 201 201 204 209 209 218 220 220 223 225 228 228 236 237 241 243 244 246 246 248 249 251 253 253 256 256 260 260 260 263 266 268 269 274 274 275 277 277 277

XIV

Table of Contents

2.13.4 Correction of Foot Deformities . . . . . . . . . . . . . . 2.14 Large Joint Pathology . . . . . . . . . . . . . . . . . . . . . . . . . 2.14.1 Shoulder . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.14.2 Elbow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.14.3 Wrist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.14.4 Hip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.14.5 Knee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.14.6 Ankle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.15 Infectious Complications of Long-Bone Fractures . . . . . . . . 2.16 External Fixation in Children, the Elderly and the Senile . . . 2.17 General Principles of Patient Management in the Postoperative 2.17.1 Position in Bed . . . . . . . . . . . . . . . . . . . . . . . . 2.17.2 Anaesthesia . . . . . . . . . . . . . . . . . . . . . . . . . . 2.17.3 Dressings . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.17.4 Exercise Therapy . . . . . . . . . . . . . . . . . . . . . . . 2.17.5 Physio- and Pharmacotherapy . . . . . . . . . . . . . . . 2.17.6 Biomechanical Device State . . . . . . . . . . . . . . . . 2.17.7 Outpatient Treatment . . . . . . . . . . . . . . . . . . . . 2.17.8 Device Removal . . . . . . . . . . . . . . . . . . . . . . . . 2.18 Mistakes and Complications of External Fixation . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Suggested Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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279 283 283 285 288 289 291 298 301 303 305 306 306 306 307 307 307 309 319 320 326 331

3

Appendix 1: Method for the Definition of “Reference Positions” for the Insertion of Transosseous Elements 333 3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333 3.2 Main Principles for the Determination of Positions with Minimum Displacement of Soft Tissues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333 3.2.1 Skin Displacement Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 334 3.2.2 Fascia Displacement Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335 3.2.3 Muscle Displacement Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335 3.3 Determination of Positions with Minimum Soft-Tissue Displacement . . . . . . . . . . . . . . . . 335 3.3.1 Femur (L. N. Solomin, M.V. Andrianov) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335 3.3.2 Upper Arm (L. N. Solomin, R. E. Inyushin) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335 3.3.3 Lower Leg (L. N. Solomin, D. A. Mykalo) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337 3.3.4 Forearm (L. N. Solomin, P. N. Kulesh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337

4

Appendix 2: Method for Rigidity Testing of External Fixation Assemblies (L. N. Solomin, P. I. Begun, V. A. Nazarov) 4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2 Indications and Contraindications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3 General Theoretical Principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3.1 Transosseous Module Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3.2 Method for the Unified Designation of External Fixation . . . . . . . . . . . . . . . 4.3.3 Modelling the Displacing Forces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3.4 Primary Standard for Rigidity of Transosseous Modules . . . . . . . . . . . . . . . . 4.4 Experimental Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4.1 Investigating Rigidity of the Transosseous Modules of the First (M1) and Second (M2) Order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4.1.1 Longitudinal Rigidity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4.1.2 Rotational Rigidity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4.1.3 Transverse Rigidity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4.1.4 Transverse Rigidity in the Frontal Plane when Modelling Abduction and Adduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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341 341 341 341 341 342 343 345 345

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345 345 346 346

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4.4.2

Index

Investigating the Rigidity of Third-Order Modules (M3) . . . . . . . . . . . . . 4.4.2.1 Rotational Rigidity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4.2.2 Transverse Rigidity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4.2.3 Transverse Rigidity in the Frontal Plane when Modelling Abduction Adduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

XV

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. . . 347 . . . 347 . . . 348 . . . 348 351

Contributors

M.V. Andrianov R. R. Vreden Russian Research Institute of Traumatology and Orthopaedics 8 Baykova Str. Saint Petersburg Russia, 195427

P. N. Kulesh R. R. Vreden Russian Research Institute of Traumatology and Orthopaedics 8 Baykova Str. Saint Petersburg Russia, 195427

A.A. Artemiev State Institute of Advanced Medical Studies Ministry of Defense of the Russian Federation 7 Cherkizovskaja Str. Moscow Russia, 141280

D.A. Mykalo R. R. Vreden Russian Research Institute of Traumatology and Orthopaedics 8 Baykova Str. Saint Petersburg Russia, 195427

P. I. Begun The State Electrotechnical University 5 Popova Str. Saint Petersburg Russia, 195007

V.A. Nazarov Marshal Novikov Str., 3–131 Saint Petersburg Russia, 195427

R. E. Inyushin R. R. Vreden Russian Research Institute of Traumatology and Orthopaedics 8 Baykova Str. Saint Petersburg Russia, 195427

A.V. Runkov Ural Scientific Research Institute of Traumatology and Orthopaedics 7 Bankovsky Str. Ekaterinburg Russia, 620014

O.A. Kaplunov The Orthopaedic Center of City Clinical Hospital No. 3 45 Sovietskaja Str. Volgograd Russia, 400005

L. N. Solomin R. R. Vreden Russian Research Institute of Traumatology and Orthopaedics 8 Baykova Str. Saint Petersburg Russia, 195427

1 General Aspects of External Fixation

1.1

Introduction

External fixation is a method for treating bone and joint injuries as well as for correcting skeletal deformities by attaching bones to an external device that stabilizes the injured limb. Additionally, it allows manipulation of the limb segments to achieve restoration of length and alignment. A synonym for external fixation is “external osteosynthesis”. In contrast, internal osteosynthesis employs devices implanted under the skin and muscle. External braces, cast splints and orthotic devices are not considered external fixators.“Extrafocal osteosynthesis”, “compression osteosynthesis” and “distraction osteosynthesis”are not synonymous with external fixation. These concepts can be utilized with either internal or external osteosynthesis.The concepts represented by these terms can be applied separately or in combination. For example, an external fixator can be used to apply compression and distraction at the same time. The term “transosseous osteosynthesis” is commonly used in the Russian-speaking literature.

1.2 Historical Background and Classification The first external fixator was described by the American J. Emsberry in 1831. In 1843, the French physician Malgaigne introduced a device for treating fractures of the patella and olecranon (Fig. 1.2.1). This resembled a clamp and was known as the Malgaigne fixator. The widespread practical use of external fixation was popularized by the Belgian surgeons Clayton Park-

Fig. 1.2.1. Malgaigne fixator

hill (1898) and Albin Lambotte (1902). In the 1930s, 1940s, and 1950s other surgeons such as Roger Anderson, Raul Hoffman, Robert and Jean Judet, and Jacques Vidal continued the development of external fixation devices by improving the clamp, pin and bar technologies. In the former Soviet Union a 30-year period of intensive development occurred beginning in the 1950s thanks to the efforts of G.A. Ilizarov, K. Sivash, O. Gudushauri, V. Kalnberz, M. Volkov, O. Oganesyan, V. Demianov and S. Tkachenko. Various types of external fixation device are shown in Fig. 1.2.2. Currently more than 1,000 external fixation devices are available in the orthopaedic marketplace. All of the external fixator devices have similar components and can be divided into six frame types (Table 1.1). Types I and II are single-plane. All the other frame types are multiplane. Only console transosseous elements (halfpin constructs) can be fixed in monolateral (type I) and sectorial (type II) external supports. The mounting of frame types IV–VI is based on wires or pins, or wires and pins in combination. All the above features are important for determining the biomechanical, clinical and performance features of each type of external fixation device. The constructions mentioned as examples of circular devices (type V) are the usual members of this group. The majority of these devices are used in the clinic as hybrid constructions with sectorial, semicircular, and circular external supports. External fixation techniques can be classified according to the following characteristics: • Insertion of transosseous elements to treat injury to bone (fracture, nonunion) and soft tissues: intrafocal, extrafocal. • Biomechanical condition between bone fragments (neutral, compression, distraction): combined (consecutive, alternating, synchronous). • Zones of mechanical inﬂuence on bone fragments: monolocal, bilocal, polylocal. • Quantity and quality of zones of osteogenesis (bone formation): monolocal, bilocal, polylocal. These techniques are discussed in later chapters devoted specifically to all aspects of external fixation.

2

1 General Aspects of External Fixation

a

b

c

d

e

f

g

h

i

Fig. 1.2.2a–i. Fixation devices. a Lambotte, b Hoffman-Vidal, c Ilizarov, d Kalnberz, e Volkov-Oganesyan, f Demianov, g Tkachenko, h Gudushauri, i Sivash

1.2 Historical Background and Classification

3

j

k

l

m

n

o

p

q

r

Fig. 1.2.2j–r. j Lee, k Barabash, l Synthes, m Biomet, n OrthoFix, o Stryker, p Taylor spatial frame, q SUV-frame, r Poli Hex

4

1 General Aspects of External Fixation

Table 1.1. Principal types of external fixation device Type

Examples

Features

I. Monolateral

Lambotte, Hoffmann, AO/ASIF, Wagner, Afaunov, Sushko

1. Built only on pins that capture both cortices but do not pass completely through the bone (console transosseous elements, known as half-pins) 2. All transosseous elements are installed in one plane and on one side 3. The free ends of the pins are fixed to longitudinal connecting bars

II. Bilateral

Charnley, Hoffmann, Vidal-Adrey, Roger-Anderson, Key, Hey-Groves, Gryaznukhin

1. Built on through-and-through Steinmann pins or K-wires 2. All transosseous elements are inserted in one plane and pass through both cortices (true transfixation pins) 3. The transosseous elements are joined using longitudinal connecting bars on each side, thus forming the “frame”

III. Sectorial (arch)

AO/ASIF, SKID

1. Pin placement is limited to sector ˛ (0<˛<180◦ ) 2. Pin divergence of up to 180◦ does not include the placing of true transfixation transosseous elements (wires and Steinmann pins) 3. Devices are attached to and built upon the console transosseous elements (half-pins, console wires)

IV. Semicircular

V. Circular

Fischer, Hoffmann-Vidal, Gudushauri, Sivash, Volkov-Oganesyan

1. External supports geometrically form sector ˇ (180≤ ˇ<360◦ )

Ilizarov, Kalnberz, Demianov, Tkachenko, Lee, Kronner, Monticelli-Spinelli, Ettinger

1. The external rings and connecting bars completely surround the limb at the level of the application

2. All types of transosseous elements can be used (Steinmann rods, K-wires, S-screws, half-pins)

2. This frame geometry can be varied to form many configurations such as a ring, oval, square, polygon, etc. 3. All types of transosseous elements can be used (Steinmann pins, half-pins, wires)

VI. Hybrid (Combined)

Biomet hybrid external fixator, Sheffield hybrid external fixator, OrthoFix hybrid external fixator, Taylor spatial frame, SUV-frame, Poli Hex

This type of external fixation device can combine all the features of types I–V

Schemes

1.3 Advantages and Disadvantages, Indications and Contraindications

When evaluating all currently available external fixation devices, the apparatus of G.A. Ilizarov is the most complete. Although the entire array of components appears very complex on initial examination, the device allows any of the types of device for transosseous osteosynthesis described above to be assembled. Additionally, it allows the use of any method of osteosynthesis alone or in combination and the application of these methods simultaneously within the same limb. Because of this versatility, we pay particular attention to this specific device.

1.3 Advantages and Disadvantages, Indications and Contraindications Each method of osteosynthesis has its own distinct advantages and disadvantages.External fixation has many advantages for the treatment of orthopaedic conditions including: 1. Minimal disruption of soft tissues within the region of trauma or fracture, with preservation of the blood supply. This is important as local vascularity is a major factor in regeneration for bone healing. 2. Provision of stable fixation outside the zone of injury. 3. The opportunity for closed reduction and repositioning of bone fragments. This can be accomplished in all three planes simultaneously. 4. Facilitation of an earlier return to function of the injured extremity. 5. The ability to manipulate the biomechanical rigidity of the fixation device as it relates to the fixation of bone fragments. 6. A variety of uses for the treatment of pathological and traumatic orthopaedic diseases. The versatility of the device provides practically unlimited potential. 7. The opportunity to make adjustments to the device based on the individual patient’s clinical and radiographic progress. Adjustments can be carried out indefinitely for the treatment of various orthopaedic conditions, including the reconstruction of bony defects. 8. The unique opportunity to study in both the clinical and basic science settings issues of bone and softtissue regeneration. The basic disadvantages of external fixation include: 1. The relative complexity of using external fixation devices, especially those of types IV–VI.

5

2. The constant monitoring of the device, with the possibilities of loosening and hardware failure. The constant threat of pin/wire site inﬂammation and deep pin tract infection throughout the entire period of frame application and use. 3. Risk of stiffness of transfixed joints (“transfixion pin-induced joint stiffness”). 4. The frequently large size of the external fixation device, which can be aesthetically unpleasing for the patient and often requires the use of special clothing to cover the device. 5. Patient compliance is perhaps the biggest disadvantage to the use of these devices as a noncompliant patient not performing the required adjustments or a third party performing ill-conceived adjustments make continued treatment problematic. External fixators can be used in a wide variety of areas including: 1. Fractures of virtually all bones of the skeleton, including the pelvis, humerus, forearm, clavicle, femur, tibia, and foot/ankle: – Frames may be applied at any level: diaphyseal, epi-/metaphyseal, intraarticular. – Simple, comminuted, segmental fractures. – Open or closed fractures. – Fractures with the potential for soft-tissue contamination and infection. 2. Malunions/nonunions: – Delayed union and nonunion. – Malunions, traumatic deformities, soft-tissue or bony defects. – Infected malunions/nonunions. 3. Orthopaedic pathology: – Congenital deformities, bony defects, segmental bone resections for pathological conditions. – Infected orthopaedic pathology. 4. Joint pathology: – Malformations. – Contractures. – Dislocations. – Dysplasia or degenerative disease. Currently, the basic indications for the use of external fixators include: 1. Fractures and dislocations accompanying softtissue damage. 2. Penetrating injuries to joints, including injuries resulting from gunshot wounds. 3. The rapid stabilization of fractures in haemodynamically unstable patients, including patients with multiple fractures or multiple injuries. 4. Fractures with extensive damage, including comminution and periosteal stripping (C3 in the AO/ ASIF classification).

6

1 General Aspects of External Fixation

5. Situations when the use of internal osteosynthesis is contraindicated in a particular patient, including the presence of acute or chronic focal infection. 6. (Infected) malunions, nonunions, traumatic deformities, and soft-tissue or bony defects. 7. (Infected) congenital deformities, bony defects, and segmental bone resections for pathological conditions. 8. Aesthetic surgery involving limb length discrepancy, malformations and malalignment. 9. In joint pathology (malformations, contractures, dislocations, dysplasia or degenerative disease). 10. Reconstructive operations: “tibialization” of the fibula, lengthening of a stump, correction of hand and foot deformities; arthrodesis (including lengthening arthrodesis). 11. External fixation is also particularly useful in patients requiring distraction osteogenesis with chronic ischemic vascular conditions, such as obliterating endarteritis, diabetes, peripheral vascular disease, etc. 12. Growing (via lengthening) of soft tissues: skin,muscles, tendons, vessels, nerves. 13. Ancillary uses, including for example, the elimination of a luxation before joint arthroplasty. Some basic contraindications to the use of external fixation include: 1. Unfamiliarity of the surgeon with the use and mechanics of external fixation,particularly distraction osteogenesis. 2. Impossibility of constant monitoring of the patient during the fixation period. 3. Inability to monitor a patient’s external fixation and fracture healing postoperatively because of social or compliance issues, or inability of the patient to follow postoperative recommendations and advice because of other factors. These may include agerelated issues, psychoemotional status, and alcohol or narcotic abuse which may inhibit a patient’s judgement regarding care and management of an external fixator. 4. Gross haemodynamic instability, in which even rapid application of spanning external fixation would compromise the patient’s prognosis. 5. Gross contamination of soft tissues, the placement of external fixator pins or wires through which would put the patient at increased risk of infection. 6. HIV-positive patients who would otherwise benefit from nonoperative management of fractures. 7. Situations when the use of external fixation has no clear advantage over conservative treatment and/or internal fixation.

1.4

Equipment

The standard complete set of Ilizarov apparatus for osteosynthesis is shown in Fig. 1.4.1. The standard instrumentation of a basic Ilizarov set for transosseous osteosynthesis includes all the available equipment (Figs. 1.4.2–1.4.12 and 1.8.2). The application of an external fixator requires basic operating room equipment including a surgical drill, and a radiolucent orthopaedic table with an attached device for applying skeletal traction. Plastic or rubber protection stoppers in diameters of 10–15 mm for pins/wires and 20–25 mm for half-pins are necessary for fixing of gauze dressings. A device for division of an extremity into levels (Fig. 1.8.2) allows a limb segment or a level to which transosseous elements can be attached to be quickly and precisely defined (see section 1.8). Additional equipment for performing “combined strained fixation” is also discussed in the same chapter.

1.5 General Terms for External Fixation Constructs Application of external fixation uses transosseous elements: • Transsegmental elements comprise transfixation K-wires and Steinmann pins. • Console elements comprise S-screws, half-pins and console wires. Exterior supports of the frame are called basic supports. Transosseous elements fixed to the basic supports are designated as basic transosseous elements.The supports located between basic supports are called reductionally fixing or intermediate supports. Reductionally fixing transosseous elements are fixed to the reductionally fixing supports (Fig. 1.5.1a). If the arrangement of the apparatus includes only the basic support on one of the bone fragments, both the basic and reductionally fixing transosseous elements are fixed to it.In this case the reductionally fixing transosseous elements are connected to the base support with the help of posts (Fig. 1.5.1b). The basic and reductionally fixing transosseous elements and supports to which they are fixed make a transosseous module fixing the bone fragment. The presence of two bone fragments implies two transosseous modules: a proximal transosseous module and a distal transosseous module (Fig. 1.5.1a). The basic support with both basic and reductionally fixing transosseous elements is also a transosseous module (Fig. 1.5.1b).

1.5 General Terms for External Fixation Constructs

a

7

b

c

d

g

e

h

f

i

j

k

Fig. 1.4.1a–k. The standard complete set for osteosynthesis utilizing Ilizarov’s method. a External supports of different standard sizes: rings, half rings, sector rings (two-thirds, three-quarter or five-eighths rings), arches. b Connecting plates of different standard sizes, including straight plates, twisted plates, curved plates. c One- to four-hole male and female posts. d Long and short connecting plates of different lengths; long connecting plates with treaded ends. e Different length connecting rods of different lengths including partially threaded, fully threaded and telescopic rods. f Slotted threaded rods: traction clips. g Smooth and stop wires of diameter 1.5, 1.8 and 2.0 mm. h Wire fixation frame (Russian only); wire-fixation bolts. i Wire tensioners; standard and dynamometric. j Bolts, nuts, lock washers, slotted washers, serrated washers, conical washers, conical and spherical washers; threaded sockets and bushes. k Regular flat-nosed and round-nosed pliers, standard 10-mm spanners

8

a

1 General Aspects of External Fixation

b

Fig. 1.4.2a,b. Lever wire tensioners: Voronkevich (a) and assembled from the standard Ilizarov set (b). These tensioners allow wires in inaccessible locations to be tightened

Fig. 1.4.3a–d. For the application of a hybrid (half-pin and transfixion wire) external fixator, utilizing cortical and metaphyseal 4-, 5- and 6-mm half-pins (a), a special ‘T’ wrench, either standard (b) or assembled from the Ilizarov set (c), is utilized. Attachment of half-pins to the frame is accomplished using multiple pin fixation clamps (d) or L-shaped clips (Fig. 1.11.7)

1.5 General Terms for External Fixation Constructs

9

Fig. 1.4.4. Cannulated drill sleeve (1) and trocar (4) assemblies are utilized for the introduction of half-pins. These are designed to protect the soft tissue from damage and allow the drill to be directed at the desired angle. The drill sleeve has an attached handle and has an inner diameter of 6.5 mm (1). The attached clamp (2) has a special guide for introduction of a calibrated wire (3) which indicates the angle of pin insertion

Fig. 1.4.5. Surgical drills. The cortex at the proposed pin site is carefully predrilled avoiding damage to the soft tissue prior to the introduction of a half-pin. A stop on the drill bits control the depth of drill penetration. Drills of different diameter are required and should include diameters of: 2.7 mm, 3.8 mm 4.5 mm and 4.8 mm

Fig. 1.4.6. Traction clips at the site of fixing of a wire have a cube shape for easy capture by a spanner

10

1 General Aspects of External Fixation

Fig. 1.4.7. Extracortical bone clamp is utilized to facilitate the introduction of a pin when the medullary canal is obstructed with a large foreign body. For example, in the case of a periprosthetic fracture the canal may be obstructed with a prosthetic device

Fig. 1.4.8. Device for the reduction of bone splinters (a fork device) when the use of a standard wire is impossible (due to, for example, projection of vessels and nerves) or not feasible (due to, for example, thickness of tissue, the splinter is in the interbone space of the forearm) (Fig. 1.6.14)

Fig. 1.4.9. Slotted female posts may be used as a clamp for half-pins and can also be used for the reduction of bone fragments by “pulling” or “pushing” the fragments (page 19; Fig. 1.6.10)

Fig.1.4.10. This device is an advanced “Barabash cube” (Fig. 1.2.2k). It assists with the reduction of bone fragments in two different planes

Fig.1.4.11. construct assembled from a pin clamp with calibrated wires can be used to assess the precision of bone fragment reduction (Fig. 1.11.4)

1.5 General Terms for External Fixation Constructs

Fig. 1.4.12. Storage and sterilization of sets requires special containers

Proximal basic support

Proximal basic transosseous elements Proximal transosseous module Reductionally fixing transosseous elements

Reductionally fixing (intermediate) supports

Distal transosseous module

Distal basic transosseous element

Distal basic support Fig. 1.5.1a. Standard arrangements of external fixation devices for fractures

11

12

1 General Aspects of External Fixation

Proximal basic support Proximal basic transosseous elements

Proximal transosseous module Reductionally fixing transosseous elements

Reductionally fixing (intermediate) supports

Distal basic transosseous element

Distal transosseous module Distal basic support

Fig. 1.5.1b. Standard arrangements of external fixation devices for fractures

1.6

Biomechanical Principles

Biomechanics of the external fixation consists of three interrelated parts:

Swivel hinge

Axial hinges

1. The relationship between the transosseous elements (wires, half-pins) and the surrounding tissues. 2. Control of bone fragment position. 3. Control of bone fragment rigidity. These are discussed in the following sections.

Fig. 1.5.2. Designation of hinges

If the device assembly includes a transosseous module applied temporarily on an adjacent segment, it is defined as an auxiliary transosseous module, and the apparatus fixing the fracture is called a basic or main one. When transosseous modules are connected by hinges, the two located diametrically opposite relative to the bone which ensure rotation of the modules along the given trajectory are called axial hinges. The hinges (or connecting rods, fixed to the modules by means of hinges) transmitting force to the modules to allow their movement are designated as swivel hinges (Fig. 1.5.2).

1.6.1 Relationship Between the Transosseous Elements and the Surrounding Tissues Clinical implementation of the knowledge of the biomechanical interrelationship between the transosseous elements and the surrounding tissue enables the bone fragments to be forcibly fixed in such as way as to reduce device destabilization occurring because of bone resorption around the wires and half-pins and the risk of pin-induced joint stiffness and inﬂammatory complications (pin-tract infections). In order to ensure the formation of an adequate bone–metal block after insertion of the wires by reducing the risk of bone burn, it is necessary to use wires with special shapes to their cutting end: feather or single-facet cutting ends (or bayonet-wires) (Fig.1.6.1).

1.6 Biomechanical Principles

a

b

13

c

Fig. 1.6.1a–c. Variant forms of the cutting end of the wires: a Three-facet. b Feather. c Single-facet

The feather cutting end partially “breaks” the canal whereas the single-facet cutting end enables a canal corresponding to the wire diameter to be formed. In addition, interrupted drilling is important at the maximal rotation rate of 850 revolutions per minute, cooling of the wire with alcohol, and regulating (up to 20 H) the axial pressure exerted upon the wire. The biomechanical principles for insertion of the half-pins also have their peculiarities. Half-pins for insertion into the diaphysis and metaphysis should be inserted respective to the cortical and spongy thread. Prior to insertion of a half-pin into diaphyseal bone, a canal is formed with a diameter corresponding to the half-pin size taking into account the density of the bone tissue. The canal diameter is 2.7 mm for a 4-mm halfpin; 3.8 mm for a 5-mm half-pin; and 4.8 mm for a 6mm half-pin. In osteoporosis, the canal diameter must be 0.1–0.2 mm less. Insertion of the half-pin through both cortical plates is mandatory. Experiments have confirmed the advantages of a thrust thread over a triangular thread [1]. It has been established that improvement in biological compatibility of the transosseous elements by forming a biologically inert (metal–ceramic) and biologically active (calcium phosphate) covering on their surface may solve the problem of providing stable fixation of the implant in the bone [1–4]. The use of transosseous elements covered with hydroxyapatite makes it possible to optimize transosseous synthesis in osteoporosis [5, 6]. Hence, the approach of developing and creating transosseous elements for a particular orthopaedic pathology should be recognized. It is well known that soft tissues are displaced relative to the bone during joint movement. Transosseous elements fix the skin, fascia and muscles to the bone which limits physiological mobility of the soft tissues. The effect of insertion of the wires and half-pins of an external fixation device can be compared to the creation of many local myofasciodeses. Thus one should consider the contractures occurring as a consequence of using an external fixation device; these are referred to as “transfixation pin-induced joint stiffness”. In the Russian literature, this phenomenon is designated as “transfixion contracture”. This factor plays an important role in the development of inﬂammation of the soft tissues due to the chronic trauma produced by transosseous elements.

1

3

2

4

Fig. 1.6.2. Reference positions of the foot for insertion of wires in the ankle-joint area

There are two main ways to prevent pin-induced joint stiffness. The first involves the creation of a“store” of soft tissue by rendering in the extremity corresponding positions for insertion of the transosseous elements through the “ﬂexor” and “extensor” surfaces of the segment (Fig. 1.6.2). The second involves insertion of transosseous elements where there is minimum displacement of the soft tissues for all possible movements of the joints adjacent to the segment. These positions serve as a basis for establishing the so-called reference positions (RPs) for insertion of the transosseous elements. These are discussed in section 1.9 and a description of the method for establishing the RPs is presented in appendix 1.

1.6.2

Control of Bone Fragment Position

To achieve ideal control of bone fragment position, the external fixation device should allow directed movement of the fragments within the three-plane space (six standard degrees of freedom) both in a single step and stepwise over time. Changes in the spatial location of the bone fragments can be achieved by: • Mutually moving the external supports with the transosseous modules fixing the bone fragments.

14

1 General Aspects of External Fixation

a

b

c

d

Fig. 1.6.3a–d. In longitudinal transference (lightening), in order to avoid angular deformation because of an eccentric effect (eccentric distension or compression), it is necessary that the transosseous modules fixing the bone fragments be connected with rods situated bilaterally relative to the bone and in the same plane. The use of circular and semicircular devices where the half-pins connecting the modules are located in two planes encircling the bone is a more reliable approach to avoiding angular deformation. Therefore in hybrid devices, establishing an additional support for distraction is recommended. The individual locations of the connecting half-pins enable special calculations to be used [7]. In the diagrams, rational (or efficient) (a, b) and irrational (or inefficient) (c, d) ways of distraction in hybrid devices are presented

1.6 Biomechanical Principles

•

the transosseous elements remain fixed in the frame. Moving the transosseous elements relative to the external supports; the external supports and the device modules remain immobile.

In practice, both methods of repositioning (moving the external supports or moving the transosseous elements) complement each other. We consider each variant in more detail in the following sections. 1.6.2.1 Moving the External Supports with the Transosseous Modules Fixing the Bone Fragments These methods are illustrated in Figs. 1.6.3–1.6.8. For transverse movement (translation) of the bone fragments, the following methods are the most commonly used: •

Establishing the connective half-pins at an angle; one should take into consideration that simultaneously with fragment displacement distraction occurs in the transverse plane (Fig. 1.6.4a). • Assembly of a uniform node (Fig. 1.6.4b). 1.6.2.2 Moving the Transosseous Elements Relative to the External Supports; External Supports and Modules Remain Immobile These methods are illustrated in Figs. 1.6.9–1.6.15. From the beginning of 1990s computer navigation for repositioning of the bone fragments has been actively developed. The majority of investigations have been concerned with so-called passive navigation: i.e. identifying the optimal assemblage of transosseous devices for fragment transference with the aid of special software [7–9]. Great attention has been paid to the software for producing the optimal assemblage of the device as well as a program for correction of congenital and acquired deformities of the long bones [10–12]. The next step in passive computer navigation involves development of devices for external fixation completely integrated with the software. For instance, when using the Taylor spatial frame (Fig. 1.2.2p), the 13 parameters identified radiographically are transformed by the computer into concrete recommendations: i.e. what changes in length of each of the six stratums is necessary in order to achieve the necessary orientation of the bone fragments [13–17]. The SUVframe (Russia) and Poli Hex (Germany) (Figs. 1.2.2q,r) devices operate by analogous principles. In this connection, the work of Glozman et al. [18] on simplifying the processing of radiographic images to generate the necessary data for input to the computer is particularly important.

15

Electronic–mechanical devices temporarily attached to the device to enable repositioning of the fragments under ﬂuoroscopy guidance [19] and devices for automatic distraction [20–23] can be considered transitional methods leading to active navigation. Active navigation, which will undoubtedly become increasingly important in the future, involves a complex of modules which automatically determine the spatial localization of the bone fragments, create the necessary trajectory for their movement, and perform this movement. The work of the surgeon would then involve superimposition of the modules onto each bone fragment, approval of the trajectory created by the machine for fragment transference and, after the automatic repositioning, assembly of the transosseous modules into an external fixation device to perform the internal fixation [24].

1.6.3

Control of Bone Fragment Rigidity

The main parameters inﬂuencing rigidity of bone fragment fixation which are significant for all types of transosseous devices are discussed below. 1.6.3.1 Material from which the Elements are Manufactured The more rigid the material of which the components of the external fixation device are manufactured, the stronger is the rigidity of the bone fragment fixation. Along with stainless steel, titanium alloys and chromium-cobalt-molybdenum alloys are used. The durability of the latter is threefold higher, whereas their mass is twofold lower. Development of synthetic polymer materials suitable for use in the transosseous device frames is continuing. As the transosseous elements are more elastic than the external supports and the bars connecting them,the rigidity of the transosseous synthesis to a considerable extent depends on the principles of insertion and use of the transosseous elements. 1.6.3.2 Number of Transosseous Elements The greater the number of transosseous elements inserted into each bone fragment, the greater the rigidity of the transosseous synthesis. One should remember, however, that a greater number of interventions leads to a proportional increase in the degree of trauma and an increase in the risk of pin-induced joint stiffness. 1.6.3.3 Diameter and Type of Transosseous Elements Increasing the diameter of the transosseous elements used will lead to an increase in the rigidity of the bone

16

1 General Aspects of External Fixation

a

b

Fig. 1.6.4a,b. Approaches to the elimination of transverse fragment displacement [10]

1.6 Biomechanical Principles

a

b

c

17

d

Fig. 1.6.5a–d. Where transverse fragment displacement is combined with angular deformation, the reductionally fixing supports are transferred using trailing bars [25]

Fig. 1.6.6. Intermediate fragment reduction. Additional information on the approaches to transference of intermediate fragments is presented in section 2.6

Fig. 1.6.7. For correction of angular deformation, the transosseous modules fixing the bone fragments are connected with a hinge subsystem. More details of Ilizarov hinges are given in section 2.8

18

a

1 General Aspects of External Fixation

b

Fig. 1.6.8a,b. Rotational transference (torsion) of fragments is carried out with the aid of a sloped arrangement of the connective half-pins (a) or assemblies of uniform derotation nodes (b). Additional information is given in section 2.8

a

b

Fig. 1.6.9a,b. The use of bent wires and/or wires with stops is a classic approach in external fixation and, owing to its high efficacy, is most often used for repositioning in fractures (a). When mastering the method of external fixation, it is better to use the wires inserted for repositioning in the frontal plane (b). For traction both wire pullers and traction clamps can be used. The use of the latter makes the repositioning simpler and facilitates maintenance of the wire pull in the postoperative period

1.6 Biomechanical Principles

a

19

b

Fig. 1.6.10a–d. To eliminate transverse displacement of a fragment, a half-pin can be used as the “pusher” or “puller”. Note that the female posts must have a longitudinal slit (Fig. 1.4.9) and the nuts must be complemented with hemispherical washers

a

b

c

d

Fig. 1.6.11a–d. This device (see also Fig. 1.4.10) enables the bone fragment to be moved in two planes. For transference of the fragment in the plane perpendicular to the plane of insertion of the half-pin, the device is moved along the threaded rod attached to the device ring. In addition, the half-pin can be used as a “pusher” or “puller” analogous to Fig. 1.6.10. In this device, there is no need to use the hemispherical washers

20

1 General Aspects of External Fixation

Fig. 1.6.12. For the transference of the transosseous elements relative to the external supports for repositioning, the following points should be kept in mind. If the basic transosseous elements are not perpendicular to the bone long axis then, changing the bone fragment spatial orientation with the repositioning/fixation wire (half-pin) will induce Zlike deformation of the basic wires (shown in the diagram) or of the basic half-pins. In this case, the bone fragment is subjected to the actions of two differently directed forces: the repositioning force induced by the action of the reductionally fixing transosseous element, and the force occurring from elastic deformation of the basic transosseous element. The latter force acts to return the bone fragment to the initial position. As a result the rigidity of the osteosynthesis is reduced, and the threat of a secondary displacement becomes greater. The deformation of the repositioning/fixation wire is not shown in the diagram. An analogous situation also arises in transference of the reductionally fixing supports (Fig. 1.6.5)

Fig. 1.6.13. Rotation of the bone fragment can be achieved by moving the wire ends in the support [10]

a

b

Fig. 1.6.14a,b. Reposition of the bone fragments with the aid of Kirschner wires (a) and console wires (b) [26, 27]

1.6 Biomechanical Principles

21

b

Fig. 1.6.14a,b. (cont.)

a

b

c

Fig. 1.6.15. Situations may arise when the use of wires and console wires for fragment repositioning is impossible (e.g. in the proximity of main vessels and nerves) or inadvisable (great thickness of soft tissue). Most often such circumstances occur if the fragment is located at the internal, posterior surface of the middle third of the humerus or femur, in the interbone space of the ulna/radius or tibia/fibula. In these cases, a fork-shaped half-pin is used (Fig. 1.4.8). When using this device on the forearm, the diameter of the repositioning wire is 2–3 mm. For example, when the bone fragment is located along the posterior surface of the femur, the device is inserted from the external side of the segment (there are no main vessels or nerves here, and the softtissue displacement is relatively small during movement of the hip and knee joints). If longitudinal displacement is required as well as transverse transference, a fork-like half-pin is used with a longitudinal channel in the shank end. In the first stage, the fragment is pressed with its fork-like curvature to the main born fragment. A 1.5-mm wire is inserted in the half-pin canal and then the bone fragment is drilled with this wire thus providing its fixation to the half-pin. The fragment is then relocated in the desired direction

22

1 General Aspects of External Fixation

fragment fixation. In clinical practice, transosseous elements of diameter from 1.5 to 6 mm are most commonly used. However, the dilemma is that along with the increase in element thickness there is an increase in the mechanical injury to tissues as well as an increase in rigidity of the “bone–device” block. Reducing the diameter of the elements reduces the rigidity, but enhancement of tension in the bone leads to its resorption, which to some extent may be compensated for by using supports and stopper tubes, or by altering the tension of the wire. Transosseous elements with an angular thread provide good rigidity of the bone–metal block. For similar diameters,transsegmental transosseous elements provide greater rigidity than console elements. 1.6.3.4 Wire Tension Insufficient tension of the wires reduces the rigidity of bone fragment fixation. The reference force of the wire strain in the ring is 900–1100 N, and in the unclosed support 500–700 N. 1.6.3.5 Levels of Transosseous Element Insertion The greater the distance between the level of insertion of the basic and reposition fixation transosseous elements of each bone fragment, the greater the rigidity of the osteosynthesis. This does not necessarily involve insertion of the wire and half-pins through the joint cavity and nearer than 2–4 cm from the pathological focus. 1.6.3.6 Plane of Orientation of the Transosseous Elements The “neutral” angle for wires crossing in the support is 60◦ . With a wider angle the wires will exert a mutual pulling action and with a narrower angle they will exert a weakening action. If it is possible to use an angle less than 45°, the external support should be oriented by the angle 45° to the most displacing efforts. But to increase support rigidity, it is necessary to insert additional transosseous elements with some distance from the support. If the transosseous elements are placed perpendicular to each other, the system will respond “universally” to possible displacing forces. The topographic– anatomical specifics of the majority of extremity segment levels, which govern the localization of the RPs, in the majority of cases will predetermine the implementation of this condition when using console transosseous elements (half-pins and console wires). The expedience of inserting a half-pin at an angle to the displacing force has been confirmed.

Fig. 1.6.16. Optimum number of connecting rods

In addition to the above parameters, the rigidity of external fixation also depends on other parameters. 1.6.3.7 Distance from the Bone to the External Support The less the distance, the higher the rigidity provided by the construction. To avoid compression of swollen soft tissues,it is necessary to provide a certain clearance between the skin and the support’s internal rim. The rim has to be established individually for each segment and type of pathological condition operated upon, and should be 1.5–5 cm. 1.6.3.8 External Support Geometry A direct dependence has been identified between the magnitude of segment coverage at each insertion level of the transosseous elements and the rigidity of the external fixation. Therefore, the trend of increasing bone fragment fixation rigidity proceeds from the type V device (circular) in the direction of the type I device. Use of closed external supports enables the wire to be stretched in an optimal way, providing a wider range of possible transosseous element insertion angles. 1.6.3.9 Number of Connecting Rods The closed (ring) supports and reductionally fixing (intermediate) and basic supports should be connected by three rods. Use of a fourth connecting rod does not increase osteosynthesis rigidity. If one or both reductionally fixing (intermediate) supports are of the open type (one-third, two-thirds or three-quarter rings), use of a fourth connecting rod increases osteosynthesis rigidity by 18–22% (Fig. 1.6.16).

1.7 Internal Contradictions in External Fixation: Combined External Fixation (CEF)

Often the requirements of each component of the external fixation biomechanics (and other requirements of the external fixation device) conﬂict with each other because of contrary requirements for the optimal solution.In this case,one should be guided by the priorities of the osteosynthesis tasks to arrive at a compromise that will maximize the efficiency factor of each transosseous element and each external support (see section 1.7). As in the case of the biomechanics involved in changing the spatial orientation of the bone fragment, the multivariance of the factors affecting bone fragment fixation rigidity in the external fixation serves as a basis for determining the directions for optimizing the assemblages of transosseous devices. Most clinical studies of the biomechanics of external fixation involve stand tests of external fixation models. The importance of the results obtained in such experiments by many researchers in different countries cannot be overestimated. However, apart from natural limitations associated with experiments involving models, the interpretation of the data and their use in practice emphasize the fact that there is no single commonly accepted method for carrying out the stand test. At present, a number of devices are known that differentiate the “original” carcass, the nodes of the model fixation, the force-generating elements, and the movement transducers. The models are assembled using native or artificial bone, wooden or plastic cylinders, or metal tubes. The model can be fixed in the carcass in different ways, the displacing force can be applied in different ways, the transducers allocated in different ways, and the algorithm for carrying out the experiment may also different. Therefore to compare the results of studies by different authors objectively is hardly possible. And the number of such studies grows yearly. In appendix 2, an unformed method for carrying out an external fixation construct rigidity test is presented. The second way of optimizing an external fixation device is mathematical modelling using computer software specially created or adapted for the tasks that need to be resolved; the efficacy of the final element method is now recognized [1, 7, 8, 10, 28–31]. However, those studies that are oriented towards provision of the optimal parameters for bone fragment fixation rigidity at all the stages of healing should be recognized as the most relevant. Intensive development is characteristic of the methods objectifying the durability of bone mechanical restoration on the basis of biomechanical, laboratory, optical, electrophysiological, radiological, and other types of monitoring [7, 32– 39]. Unfortunately, at the time of writing, not one of these methods, for various reasons, has been widely applied in clinical practice. One should also recognize the fact that, up until now, no unanimous opinion exists

23

of what the bone fragment fixation rigidity should be at all stages of the bone anatomy restoration. In conclusion, it should be noted that biomechanics is an intensively developing field of knowledge. There are a relatively large number of published works dedicated to the biomechanics of osteosynthesis (including the biomechanics of external fixation). Therefore we can expect that a solution to the above problems will be found in the relatively near future.

1.7 Internal Contradictions in External Fixation: Combined External Fixation (CEF) Assembly of an external fixation apparatus needs to accord fully with current developments in transosseous osteosynthesis. The experimental/theoretical and clinical knowledge base is now such that the rigidity of bone fragment fixation in relation to the diameter of the transosseous elements used,their type and crossing angle, the geometry of the external supports, the distance between external supports etc. can be predicted.As discussed above, external fixation biomechanics consists of three interconnected parts: 1. The relationship between the transosseous elements (wires,half-pins) and the surrounding tissue. 2. The control of bone fragment position. 3. The control of bone fragment rigidity. These components of external fixation biomechanics quite often mutually conﬂict because of opposite requirements to achieve the optimum result. Most often the requirement to control bone fragment rigidity is central to internal contradictions of external fixation (Figs. 1.7.1–1.7.3). There are also contradictions among some other important factors in the assembly of the external fixation device. These include, for example: piezoelectric effects,frame automation and monitoring,convenience of the frame use, and patient comfort. Thus no external fixation device is perfect. In the term “contradictions in external fixation” we use the word “contradictions” in a positive sense implying opposed interaction and interconnected essence as sources of self-movement and development [40]. In other words, Ozhegov et al. [37] means that contradiction (in the philosophical sense) is interaction (intercommunion) of opposed and interconnected (interdependent) essences (entities, things) as sources (generators) of self-movement and development. According to this definition, external fixation has a significant potential for optimization.

24

1 General Aspects of External Fixation

Fig.1.7.1. The diameter of the transosseous elements can be increased to increase the rigidity of the osteosynthesis. However, this will result in greater operative damage. Increasing the number of wires and half-pins increases the rigidity of bone fragment fixation. However, this will increase both operative damage and the danger of transfixion pin-induced joint stiffness due to polylocal myofasciodeses and of pin-tract infection. Increasing the distance between the supports in the modules fixing each bone fragment contributes to the rigidity of fixation. However, this will increase the bulkiness of the frame. Moreover, the danger of transfixion pin-induced joint stiffness increases because the level of wire insertion approaches the joints

Fig. 1.7.2. Orienting the transosseous elements at angles in the range 50–◦ 90◦ to each other will increase the rigidity of the osteosynthesis. However, pin-induced injury to the principal vessels and nerves may be seen in some cases. The risk of transfixion pin-induced joint stiffness and pin-tract infection increases as well

a

b

Fig. 1.7.3. A circular apparatus provides the greatest opportunity for fragment reduction and is the most rigid. However, at the same time such a device has the largest dimensions in comparison with other types of external fixation device. Arranging the bone fragments in the centre of a ring support tends to increase the stability and to simplify the management of the fragments. However, this requirement means the ring diameter increases, and because the rigidity of the osteosynthesis is reduced, the dimensions of the apparatus need to be increased

1.7 Internal Contradictions in External Fixation: Combined External Fixation (CEF)

Thus two questions may arise: what type of frame configuration to select for further external fixation advancement, and whether improvement in the construction of any type of frame can resolve all the existing internal contradictions of modern external fixation. In our opinion, these questions are not appropriate. We consider that the development of just one type of external fixation device would lead the scientific and clinical studies in the wrong direction. In our opinion, a special“set of criteria”(requirements) should be developed and used for the frame to be clinically effective, that is to resolve a particular clinical problem. We apply the following principles to the construction of an external fixation device: 1. The use of the “Method for the Unified Designation of External Fixation” (MUDEF). 2. The use of different types of external support (closed circular, and open semicircular, sectorial, bilateral or monolateral) and transosseous elements (transsegmental wires and Steinmann rods, and console S-screws, half-pins and console wires) due to special indications. 3. Establishment of “reference positions”(RPs) for insertion of transosseous elements. 4. The use of the minimum number of external supports and transosseous elements to provide a quality of reduction and fixation of bone fragments that is not worse than that provided by the Ilizarov fixation device. 5. Consideration of the possibility of applying “module transformation” (MT) of the external fixation device. 6. Opportunity of computer navigation application for planning and using of osteosynthesis.

1.7.1 Method for the Unified Designation of External Fixation (MUDEF) The notion of MUDEF is discussed in section 1.8.

1.7.2 Use of Different Types of External Support and Transosseous Elements The types of external support and transosseous elements used are determined on the basis of a reasonable compromise in accordance with the principles of frame construction discussed in section 1.11. The information provided in section 1.9 is also used.

1.7.3

Reference Positions

Use of the system of RPs reduces the risk of damage to the main vessels and nerves, and the occurrence of transfixion pin-induced joint stiffness and pin-tract

25

infections. Detailed information is provided in section 1.9.

1.7.4 Minimum Number of External Supports and Transosseous Elements Finally, the parameters to achieve bone fragment fixation rigidity at each stage of bone fragment union have not being established yet. Therefore, the aspiration of many authors to achieve rigidity of an osteosynthesis greater than that provided by the Ilizarov device, in our opinion, is not always achieved. Thus it is necessary to note that the Ilizarov device has provided efficient reduction and fixation of bone fragments over decades of its application. Thus the design of the Ilizarov apparatus can be taken as the standard for external fixation.

1.7.5

Module Transformation

MT involves the following: • Gradually decreasing the quantity of connecting rods and transosseous elements. • Reducing the quantity of supports without insertion of additional transosseous elements. • Changing the geometry of the external support by dismantling a part of it. The use of MT enables the conditions for bone fragment union (“regenerate training” in Ilizarov’s terminology) to be optimized, the risk of transfixion pininduced joint stiffness and pin-tract infections to be reduced, and patient comfort to be increased by decreasing frame bulkiness. Examples of the successful use of MT in clinical practice are presented in the second part of the book.

1.7.6

Computer Navigation

Application of computer navigation is the most advisable at correction of two and three-plane deformations. We have developed the device SUV-frame (page 3, Fig. 1.2.2.q), which as against known hexapods (Figs. 1.2.2.p and 1.2.2.r) conforms to all above-named (sections 1.7.1–1.7.5) requirements. As the attention in this manual is given to “classical” ways of bone fragment reduction, the following publications will be devoted to features of SUV-frame application. Discussion of external fixation in terms of the above six criteria has the aim of lifting external fixation to a new qualitative level which makes appropriate designation of the direction of external fixation necessary. Under this method of external fixation a conjunction and a combination of different types of support, transosseous elements and the biomechanical conditions

26

1 General Aspects of External Fixation

between supports is implied. Thus, it is logical to consider external fixation in relation to two terms: • Conjunctive (combinative) external fixation. • Combined external fixation. According to the dictionary [40],“conjunction”is a connection, the arrangement of parts to form a whole, the whole, connection in mutual conformity. “Combination” is a connection, or the arrangement of parts to form a whole, or the whole, or connection in mutual conformity of something usually congenerous. This is a complicated idea; a system of ways for achieving a particular goal; a number of ways united with a common aim and directed towards achieving an advantage. An overall analysis of terms used in the orthopaedic literature reveals phrases containing the word “hybrid”: “the hybrid osteosynthesis”, “hybrid external fixation”, “osteosynthesis by a hybrid device”. The idea of these terms changes from a combination of external and internal fixation [41, 42] to a combination of two types of external fixation device, for example, AO tubular external fixer and the Ilizarov frame [43–45]. The term “combined” includes the concepts contained in the term “conjunction”. That is why it is universal and terminologically more acceptable for the situation under consideration.It is also worth mentioning that the expression “combined osteosynthesis” has not yet been widely accepted. Definitions of combined osteosynthesis in the literature include: 1. The use both of external and internal fixation for the osteosynthesis of one bone [46–52]. 2. Simultaneous use of several types of implants on one bone; for example, a nail and a wire [53–57]. 3. Osteosynthesis of each bone of a two-bone segment by different types of fixator; for example, in the case of forearm fracture, plate osteosynthesis of the radius and nailing of the ulna [58]. 4. The application of an external fixation device with the external supports having different geometries: circular, semicircular, sectorial [59]. 5. Different biomechanical states between supports of the frame; for example, alternating compression and distraction [60, 61]. 6. Bone fragment fixators of different types of material; for example, metal and polymer [62]. 7. The use of a “wire-pin” frame assembly together with bone grafting [63]. 8. A combination of internal fixation and the insertion of various materials into the fracture gap to stimulate bone callus formation [64]. 9. Simultaneous use of an implant and bone cement for bone fragment fixation [65, 66]. We believe combined osteosynthesis implies the conjunction in one bone of fixators with two or more

biomechanical modes of interaction with bone to enhance the efficiency in achieving the aims of osteosynthesis: achievement of the necessary spatial arrangement of the bone fragments, rigid fixation of the bone fragments, and maintenance (improvement) of function of the extremities in the postoperative period. For accuracy of definition, the terms “associative” or “conjunctive” osteosynthesis should be used for cases involving the separate osteosynthesis of two-bone segments using different bone fixators, and the expression“osteosynthesis with a combined fixator”should be used for cases where the bone fixator consists of different materials, for example, metal and polymer. Finally, an expression such as “a combination of an osteosynthesis device and an additional substance” should be used in cases where, to achieve the goals of treatment, various materials are inserted at the location of the fracture to increase the rigidity of the osteosynthesis or to stimulate bone formation. A combined osteosynthesis can be classified as follows: 1. Uncontrolled combined osteosynthesis (internal fixation) which is either (1.1) neutral or (1.2) compressive with one-stage compression or dynamic compression. 2. Controlled combined osteosynthesis which is either (2.1) a combination of internal fixation and external fixation or (2.2) combined osteosynthesis with external fixation. Both experimentally and theoretically it has been established that the biomechanics of bone fragment fixation with wires and half-pins differ greatly from each other [10, 22, 67–71]. The biomechanics of devices based on wires and half-pins also have unique features [72–78]. Therefore osteosynthesis using a wire/half-pin hybrid apparatus should classified in subgroup 2.2. Thus, using the definitions and classification above, the term “combined external fixation” has a quite particular meaning. For combined external fixation and for osteosynthesis using a wire/half-pin device, devices with both wires and half-pins can be used. For “hybrid external fixation” wires, half-pins and various types of external support can also be used. Hence, we can define “combined external fixation” as “wire/half-pin-based external fixation” or “hybrid external fixation”. Furthermore, if the set of criteria (requirements) are not used, we cannot compare combined external fixation with “wire/half-pin-based external fixation” or “hybrid external fixation”. Thus, combined external fixation is not a thing created artificially. It incorporates the best practices of external fixation using all types of transosseous devices and the advances achieved by the authors and advocates of the types of external fixation discussed above.

1.7 Internal Contradictions in External Fixation: Combined External Fixation (CEF)

The most frequently used combined external fixation frame assembly is a group VI external fixation device (Table 1.1, page 4). But the use of such an assembly may not be strictly necessary. In some cases, the tasks of osteosynthesis may be achieved in an optimum manner using sector, semicircular, circular and even monolateral configurations. However, we repeat that the full set of requirements for combined external fixation should be observed, as the named principles of transosseous element insertion and apparatus assembly allow the internal contradictions of external fixation described above to be mostly overcome. The Russian Federation patents on which the method of combined external fixation is based are listed below: 1. 1657168: a method for clavicle defect treatment (authors: A.P. Barabash and L.N. Solomin) 2. 1750665: a method for long bone osteosynthesis (authors: A.P. Barabash and L.N. Solomin) 3. 4706740: a method for wire insertion and a device for its realization (authors: A.P. Barabash and L.N. Solomin) 4. 2062611: a method for tibial bone fracture osteosynthesis (authors: A.P. Barabash, L.N. Gordienko,V.P. Culms, N.V. Tishkov and Shevchenko V.V.) 5. 2069994: a method for proximal femur deformity correction (authors: A.P. Barabash and L.N. Solomin) 6. 2089099: a device for definition of an angle and the level of wire insertion (authors: A.P. Barabash and L.N. Solomin) 7. 2121814: a method for proximal part forearm bone reconstruction (authors: A.P. Barabash, L.N. Solomin and J.A. Barabash) 8. 2123307: a method for treatment of long bone damage and a device for its realization (authors: A.P. Barabash and L.N. Solomin) 9. 2139005: a device for external fixation (authors: L.N.Solomin,A.P.Barabash,M.E.Puseva,S.A.Yevseyev and N.B. Svarchevsky) 10. 2160060: a method for bone cyst treatment and a device for its realization (authors: L.N. Solomin, A.P. Barabash and A.V. Erusalimtsev) 11. 2202967: a method for replacement of long bone defect (authors: L.N. Solomin,A.P. Barabash, J.A. Barabash) 12. 2193368: a clamp for external fixation (authors: L.N. Solomin, N.V. Kornilov,A.V.Vojtovich, O.P.Shabaldo, V.V. Dolgopolov and V.A, Nazarov)

27

13. 2202967: a device for bone drilling (authors: L.N.Solomin, N.V. Kornilov,V.A. Nazarov, I.V. Shaljuga and J.V. Stetsjunich) 14. 2199967: a method for humeral bone transosseous osteosynthesis (authors: A.P. Barabash, J.A. Barabash and L.N. Solomin) 15. 2202300: a method for skeletal traction (authors: L.N. Solomin, S.A. Evseeva) 16. 2206286: a method for reduction of chronic dislocations of a humeral bone (authors: L.N. Solomin, N.V. Kornilov, A.V. Vojtovich, E.A. ShChepkina, S.V. Gavrilov, V.A. Nazarov and V.J. Komogortsev) 17. 2218083: a method for definition of soft-tissues displacement and a device for its realization (authors: L.N. Solomin, A.V.Vojtovich, M.V. Andrianov, V.A. Nazarov, R.E. Injushin and P.P. Kulesh) 18. 2233640: a device for bone fragment repositioning and fixation (authors: L.N. Solomin, N.V. Kornilov,A.V.Vojtovich,V.A. Nazarov, M.E. Puseva and M.V. Andrianov) 19. 2246139: a method for external fixation construct rigidity testing and a device for its realization (authors: L.N. Solomin, A.V. Vojtovich, P.I. Runner, V.A. Nazarov and M.V. Andrianov) 20. 2257866: an extracortical clamp device (authors: L.N. Solomin, N.V. Kornilov, M.V. Andrianov, V.A. Nazarov, P.N. Kulesh and R.E. Injushin) 21. 2261675: a method for tibia and fibula external fixation (authors: L.N. Solomin, N.V. Kornilov, V.A. Nazarov and D.A. Mykalo) 22. 2250085: a method for bone graft fixation in treatment of long bone defects (authors: L.N. Solomin, N.V. Kornilov and S.P. Lushnikov) 23. 2270631: a method for humeral bone combined external fixation (authors: L.N. Solomin and R.E. Injushin) 24. 2290888: a method for ulnar bone combined external fixation (authors: L.N. Solomin and P.N. Kulesh) 25. 2293535: a method for femur lengthening (authors: L.N. Solomin and M.V. Andrianov) 26. 2303416: the patent of the Russian Federation. The device for bone fragment reduction in external fixation (authors: L.N. Solomin, J.S. Zakutnev, V.A. Vilenskij, P.N. Kulesh, P.P. Oganezov) In the present book, alongside original methods of external fixation developed at the Russian Ilizarov Scientific Center,device assemblies meeting the criteria for combined external fixation are presented.

28

1 General Aspects of External Fixation

1.8 Method for the Unified Designation of External Fixation (MUDEF) 1.8.1

Introduction

External fixation is a high-tech procedure for the treatment of patients with orthopaedic and traumatological profiles. Consequently, the type of transosseous element (K-wires, S-screws, half-pins), their levels and their crossing positions, the levels of the external supports of the fixator, and the biomechanical relationship between the supports must be strictly regulated (normalized). Text annotations, even accompanied by explanatory figures, may be grossly inaccurate because they leave too much room for data interpretation. The threedimensional image achieved using the computer technique is by far the most precise approach; however, the creation of models for all situations encountered in external fixation is very expensive and laborious. With the use of a minimal number of symbols, MUDEF of long bones provides a comprehensive description of the type and spatial orientation of the transosseous elements, the order and direction of their crossing, and the form (geometry) and dimensions of the external supports, as well as the biomechanically indicated relationship between the supports. Additionally, MUDEF provides other advantages: • Study of the method of external fixation: Using MUDEF in instructional lectures, monographs, manuals and original articles allows accurate recording of the whole algorithm of the operation and avoids failure of the method due to inaccuracy and mistakes during its implementation. • Elimination of pin-induced damage to neurovascular structures: In Germany,Italy,the USA and Russia atlases have been published which identify schemes for the transverse sections of the extremities and designate the sectors where it is dangerous to pass K-wires and half-pins. The use of the coordinates in any of the atlases significantly facilitates definition of the dangerous sectors and safe corridors during the operation. • Facilitation of routine work during the recording of external fixation operations to produce a record that is self-explanatory. • Improvement in the accuracy and comprehensiveness of remote consultations (including teleconsultations): The method allows the recommended configuration of the external fixation device for a specific case to be sent and received, and adequate data exchange during online conferencing/consultations.

• Facilitation of the updating of the computer database: the optimal configurations of external fixation devices in cases of different orthopaedic and traumatological pathology can readily be stored. • Estimating and detailing of complications: For example, pin-tract infections are the most often seen complication in external fixation. The method allows identification of the levels and positions at which pin-tract infection occurs most frequently. Similarly,the transosseous elements that cause pain and limit the range of motion of the joints; and also be identified. • Unification of scientific research on external fixation devices: the most important advantages of external fixation devices are that they allow change in the spatial orientation of bone fragments (reduction; and rigidity of fixation with retention of extremity function. The method allows selection of the optimal device configuration. • Increasing the accuracy in the description of a local area: the locations of punctures, incisions and drains can be defined. • Overcoming language barriers and establishment of a universal international code for description of external fixator constructions.

1.8.2

Symbols Used

The standard and additional symbols used in MUDEF are shown in Table 1.2.The additional symbols improve the comprehensiveness and quality of the information while using MUDEF,but they are not strictly obligatory.

1.8.3

Coordinates

MUDEF of the long bones is based on coordinates.With the help of these coordinates each segment of the extremity is divided vertically (into levels) and horizontally (into positions).

1.8.4

Levels

Vertically each segment of the extremity is divided into eight basic and equally spaced levels designated by Roman numerals from I to VIII (Fig. 1.8.1). The device illustrated in Fig. 1.8.2 is used for rapid designation of all or any one of the basic levels.

1.8.5

Positions

Each transverse section at each level is divided into 12 equal radiating sectors (similar to a clock-face); the sectors are defined by positions 1 to 12. The long axis of the bone is the centre of division of each level into the 12 sectors (Figs. 1.8.3 and 1.8.4).

1.8 Method for the Unified Designation of External Fixation (MUDEF)

29

Table 1.2. Standard and additional symbols used in MUDEF

Standard symbols • Roman numerals from 0 to IX designating the level of K-wire or S-screw insertion • Arabic numerals from 1 to 12 designating the positions of K-wire or S-screw insertion • “ , ” (comma) between symbols for level and position, and between symbols for position and orientation of S-screw insertion • “—” (dash) between symbols for positions in the projection of which a K-wire is passed • “ ; ” (semicolon followed by a space) divides the groups of symbols defining the transosseous elements • Numerals indicating angle of insertion of Sscrews (in degrees) • “( )” (parentheses) contain the designation for transosseous elements passing through radius or fibula

Additional symbols • For olive K-wire designation the corresponding position is indicated in bold type • Numerals defining order of insertion of transosseous elements • The designations for the transosseous elements comprising one device are underlined with a continuous line indicating that they belong to that device • Symbols for designating the device type: mon. monolateral,bil. bilateral,sec. sectorial,sem. semicircular, cir. circular, hyb. hybrid • Symbols for designating the device form (geometry); for example, 3/4 indicates a three-quarter circle missing a 90◦ section; 1/2 indicates semicircle, etc. • Numerals indicating the dimensions of the support in millimetres; for example, the diameter of a circular support • Symbols designating biomechanical relationships between the supports: —— ←→ →← ––o–– ←o→

Fig. 1.8.1. Division of each segment into levels. Levels I and VIII are located in the metaphyses of the long bones, that is where the proximal and distal basic transosseous elements are passed in the majority of external fixation operations. Level I of the humerus is the level of the greater tuberculum (40 mm distal from the acromion), and level VIII is the level of the epicondylus lateralis. Level I of the forearm is at the level of the collum of the radius (40–50 mm distal from the apex of the olecranon), and level VIII is 30 mm proximal from the apex of the styloid process of the radius. At level I of the femur is located the most prominent lateral part of the greater trochanter, and at level VIII the epicondylus lateralis. Level I of the lower leg is at the level of the tibial tuberosity, and level VIII is one of the distal tibiofibular syndesmoses. Levels 0 and IX are located at the proximal and distal epiphyses of the bones of each segment, and are rarely used in external fixation. The distances between levels 0 and I and between levels VIII and IX are less than the distance between the basic levels

30

1 General Aspects of External Fixation

Fig. 1.8.2. This device is used for rapid designation of all or any one of the basic levels. It consists of 14 jointed laths each measuring; 80 × 30 mm. The side joints of the device are into the projections of levels I and VIII, and the whole segment will be equally divided to give the location of every level. An elastic tape marked with each of the eight levels can be used for the same purpose

a

b

Fig. 1.8.3a,b. Designation of positions at level IV on the right (a) and left (b) femurs. By convention, position 3 is always located on the medial surface of the segment, and position 12 anteriorly. Applying this guideline avoids failure during the designation of positions on the right and left extremity. According to the topographicoanatomical features of the humerus and the femur, positions 2, 3, 4 and 5 can only be imagined theoretically at levels 0 and I (and in some individuals, also at level II)

1.8 Method for the Unified Designation of External Fixation (MUDEF)

a

31

b

Fig.1.8.4a,b. Designation of positions on the ulna (a) and radius (b) at level IV of the right forearm in the mid-position between supine and prone). Thus, 24 positions are indicated at each of the ten levels of the forearm and the lower leg: 12 positions relative on each bone of the segment

Fig.1.8.5. For the designation of K-wires passing perpendicular to the long axis of the segment, the following conditions must be marked: level of passing and, after a comma, two positions through which it is consistently passed. Positions through which a K-wire is consistently passed are separated using an en dash (–). A K-wire with an olive is designated using the corresponding position in bold type. This designation is the clarifying one. For example, if a K-wire with an olive is passed at level IV in the frontal plane, in a lateral to medial direction, then it is designated IV,9-3

32

1 General Aspects of External Fixation

Fig. 1.8.6. If a K-wire with an olive is passed at an angle to the long-bone axis, that is from one level to another (for example, from level III to level IV) in a lateral to medial direction, then it is designated III,9-IV,3

Fig. 1.8.7. Designation of K-wires passing through both bones of the forearm in standard (a) and clarifying (b) variants. Positions relative to the radial bone are not shown. In the mid-position of the forearm (between supine and prone) at the majority of levels (except level I) the ulna and radius are located one above the other. That is why positions 6 and 12 of both bones are also located one above the other. In such a case a K-wire with an olive passing at level VIII from the side of the ulna can be represented as follows: position 6 of the ulna → position 12 of the ulna → position 6 of the radius → position 12 of the radius. That is why the VIII,6-12 designation corresponds to a K-wire through the ulna. Doubling the designation by adding a designation in parentheses (VIII,6-12) shows that the K-wire passes through the radius as well. If a K-wire with an olive passes at level VIII of the forearm from the side of the radius, then it is designated (VIII,12-6)VIII,12-6. The proximal radioulnar joint is not strictly located in the sagittal plane. That is why the common designation for the ulna and radius at level I is axis 5-11 (and not 6-12 as for all the other levels). Thus, it is necessary to designate a K-wire with an olive (passing at level I, consequently beginning with the ulna through both bones) as shown in Fig. 1.8.7(1). A K-wire with an olive passing at the level I of the forearm from the side of the radius is designated (I,11-5)I,11-5. Note that the parts of the designation indicating the ulnar and radial parts of a K-wire are not separated by a space

1.8 Method for the Unified Designation of External Fixation (MUDEF)

33

Fig. 1.8.8. Designation of a half-pin inserted at level II in the projection of positions 8, at an angle of 60◦ to the longitudinal (anatomical) axis of the tibia

Fig. 1.8.9. Examples of designations of console wires passed through both forearm bones. The positions relative to the radius are not shown

1.8.6 Designation of Transosseous Elements In MUDEF of the forearm and lower leg,the symbols for the transosseous elements inserted through the radius and fibula, respectively, are enclosed in round brackets. Transosseous elements introduced between the levels (positions) are designated with the symbol of the level (the position) close to which the transosseous elements are to be located.

1.8.7

Designation of K-wires

For transsegmental transosseous elements (for example, K-wires, Steinmann rods, Kalnberz rods, etc.) it is necessary to designate two positions on opposite sides of the bone, for example 3 and 9, 6 and 12, 1 and 7, etc. (Figs. 1.8.5 and 1.8.6). The annotation V,2-5 indicates that the K-wire is out of the bone. This system can be used for the designation of a drain placed at this level in the projection of the mentioned positions.

34

1 General Aspects of External Fixation

Several positions of the ulna and radius (and the tibia and fibula) overlap.For MUDEF this circumstance plays a role in designating K-wires that pass through both bones of the forearm or lower leg. Thus the same K-wire may need to be designated twice: for the part that passes through the ulna (tibia) and the part that passes through the radius (fibula) (Fig. 1.8.7). Another example would be: “a K-wire with an olive was passed at level I of the lower leg at the side of the fibula, in the projection of positions 8 and 2”. Using MUDEF this description is designated as follows: • Standard variant (a): (I,8-2)I,8-2. • Clarifying variant (b): (I,8-2)I,8-2.

1.8.8

Designation of Half-Pins

To accurately designate console transosseous elements (half-pins, S-screws, stiletto-formed and curved rods, and console wires) it is necessary to indicate after a comma the following (Fig. 1.8.8): • The level of console transosseous element insertion. • The position of its insertion. • The orientation of its insertion in relation to the long bone axis (anatomical axis). By convention the angle is open proximally. Where the console transosseous element is passed through both bones, it is designated using the symbol of only one position because the skin is perforated only at one side; for example VIII,6,90(VIII,6,90) (Fig. 1.8.9). This differs from the designation of a K-wire passing through both bones (Fig. 1.8.7).

1.8.9 Designation of the External Support Frame To encode the device supports the designations of each transosseous element (K-wire, S-screw) fixed to the common support are separated by semicolons and spaces (Figs. 1.8.10 and 1.8.11).

1.8.10

Designation of the Whole Device

To designate the configuration of the whole device (Figs. 1.8.12–1.8.15), between the symbols for the external supports certain other symbols are inserted to represent the recommended biomechanical relationship between them: —— neutral →← compression ←→ distraction ––◦–– hinge ←◦→ distraction hinge

1.8.11

Additional Data

If necessary, the number of levels and positions can be increased,for example,up to 30 levels and 360 positions. The following notes correspond to such conditions, for example: XXII, 162-342; XVIII, 273,65. If necessary, besides increasing the number of levels and positions, the MUDEF user can apply the additional symbols. They identify the type of console transosseous element (for example, S-screw, half-pin, hooked rod), the material (from which the external device supports and transosseous elements are made),the diameter of the transosseous elements connecting the supports of the bar, etc. We recommend using text descriptions while designating the transosseous elements introduced into the anatomical formations that are not included in the given schemes as follows: • Example 1: the phrase “Two mutually crossing Kwires were passed through the acromion of the scapula and fixed to one external support” is designated “acr.,1-7; acr.,5-11.” • Example 2: the phrase“The half-pin was passed into the posterior surface of the olecranon at an angle 90◦ ” are designated “olecr.,6-90.” • Example 3: the phrase “A K-wire was passed through the talus in the frontal plane” are designated “talus,3-9.” During completion of the operative record only the following features of the procedure need to be recorded in text form: the operative approach, the characteristics of the tissues, and any complications that arose. This procedure for the completion of the operative record results in medical documentation that is comprehensive and unambiguous as can be seen from the records given as examples below: • Additionally the element II,1,60 was passed and fixed to the proximal device support. • It is recommended that the contralateral compression of the fragments (1 mm per week) be performed using the wire traction device V,9-3. • Due to incision of the soft tissue near S-screwV,2,90, the screw was changed to K-wire V,4-10. • The signs of inﬂammation appeared in the region of K-wire VI,4-10 exit in position 4. The last two examples illustrate the significant role of MUDEF of long bones in the process of objectification of complications. An electronic version of MUDEF can be obtained at miito.org/solomin/download/mudef.zip or http://miito.org/solomin/download/mudef.zip

1.9 Atlas for Insertion of Transosseous Element Reference Positions

I,9-3; II,1,70 1

35

(a)

2

I,9-3; II,1,70

(b)

3/4 150

Fig. 1.8.10. Example of the designation of a hybrid (K-wire/S-screw) support in standard (a) and clarifying (b) variants. When the additional symbols are used, all the designations of the transosseous elements fixed to the present support must be united below using an unbroken line. For the designation of the order of insertion of the transosseous elements (sequence for performing the osteosynthesis),numbers corresponding to the order of priority of passing the transosseous elements are given above the designation of the K-wires and half-pins. Under the unbroken line the other additional symbols define the form (geometry) of the support (for example, 3/4 defines a three-quarter circle, i. e. without a 90◦ section, 1/2 a semicircle, etc.) and define the dimensions of the support in millimetres (for example, the diameter of the circle support)

(VII,11,120); VII,8,120; VIII,6-12(VIII,6-12) 2

(a)

1

3

(VII,11,120); VII,8,120; VIII, 6 -12(VIII,6-12) 120

(b)

Fig. 1.8.11. Diagram of a support mounted at level VIII of the forearm in standard (a) and clarifying (b) variants according to the following description: “K-wire with an olive from the side of the ulna is passed through the distal metaphyses of both forearm bones. S-screw is inserted into the radius at level VII in the projection of position 11 at an angle 120◦ . The second S-screw is inserted into the ulna at level VII in the projection of position 8 at an angle 120◦ to the long axis of the bone. All the transosseous elements are fixed to the 120-mm circular support”

1.9 Atlas for Insertion of Transosseous Element Reference Positions The atlas of positions forcorrect transosseous element insertion utilizes the coordinate system of MUDEF. Each limb segment is divided into eight principal levels, and each level is marked with 12 positions. The major blood vessels and nerves at each level are grouped into special zones, with the zones designated

by the letters A, B, C and D. Due to the characteristically variable anatomy, and taking into consideration the possible changes in surface anatomy due to displacement of the bone fragments, the areas adjacent to the vessels and nerves are considered “contraindicated positions” for insertion of transosseous pins or wires. Of the 12 positions, those remaining after disallowing the contraindicated positions are considered “safe positions” which will allow insertion of transosseous elements without damage to the principal vessels and nerves.

36

1 General Aspects of External Fixation

I,7-1; I,11-5 —— IV,3-9 →← V,9-3 —— VII,8-2; VII,10-4 1

2

5

6

130

130

3

I,7-1; I,11-5 —— IV,3-9 →← V,9-3 —— VII,8-2; VII,10-4 3/4 140

(a)

4

3/4 130

(b)

Fig. 1.8.12. Example of MUDEF of a humeral bone fracture 12-A3 in standard (a) and clarifying (b) variants according the description: “K-wire with an olive is inserted through the proximal metaphysis of the humeral bone at right angles to the long axis of the segment and oriented at an angle 75◦ to the frontal plane from posterior to anterior. A second K-wire is passed in the same plane as the first at an angle 30◦ to it. Two K-wires are passed through the epicondylar region of the humerus at right angles to the long axis of the bone in the transverse plane and oriented at 30◦ to each other (the angle in opened outside). The Ilizarov device is mounted using three supports with a diameter of 130 mm and one (proximal) support with a diameter of 140 mm. In such cases the basic supports of the device are geometrically mounted as three-quarters of the circle. To reduce the bone fragments, two K-wires with a stop are inserted in the frontal plane, the first at a distance equivalent to one-third of the length of the diaphysis from the proximal end in a medial to lateral direction; and the second at a distance one-third from the distal end in a lateral to medial direction. The interfragmental compression is given

(I,8-2)I,8-2; I,4-10; II,1,60 ← → IV,2-8; IV,4-10 →← VII,1,120; (VIII,8-2)VIII,8-2; VIII,4-10 1

2

3

7

8

6

4

(I,8-2)I,8-2; I,4-10; II,1,60 ← → IV,2-8; IV,4-10 →← VII,1,120; (VIII,8-2)VIII,8-2; VIII,4-10 150

150

150

(a)

5

(b)

Fig. 1.8.13. Designation of the bone transport operation (replacement of a tibial defect by lengthening of the proximal fragment) in standard (a) and clarifying (b) variants. Note that the designation (1,8-2)I,8-2 shows that the olive of the K-wire is located on the fibula. The designation of the K-wire (VIII,8-2)VIII,8-2 shows the same

1.9 Atlas for Insertion of Transosseous Element Reference Positions

0,3-9; 0,8-2 —◦— II,2,90; IV,2,90; V,2,90 1

2

3

4

(a)

5

0,3-9; 0,8-2 —◦— II,2,90; IV,2,90; V,2,90 2/3 160

(b)

mon

Fig. 1.8.14. Designation of the Biomed-Merc device in standard (a) and clarifying (b) variants

II,1,90; II,9-3; III,12,90 —◦— V,12,90; VI,1,90 2

1

3

4

5

II,1,90; II,9-3; III,12,90 —◦— V,12,90; VI,1,90 150

(a)

150

Fig. 1.8.15. Designation of the Taylor spatial frame in standard (a) and clarifying (b) variants

(b)

37

38

1 General Aspects of External Fixation

“Reference positions” (RPs) for transosseous element insertion are indicated at each level with an arrow. RPs are located where the displacement of soft tissues is at a minimum during movement of the adjacent joint (the method for defining RPs is described in appendix 1). Thus, the designation and use of RPs allows: • The avoidance of damage to the principal vessels and nerves. • A reduction in the incidence of pin-induced joint stiffness and contracture. • A reduction in the incidence of infectious complications (pin-tract infection). Diagrams of anatomic functional sections for each segment are shown below. Note that RPs are not located at all levels and are located symmetrically across a bone; for example, positions 3 and 9, 1 and 7, 6 and 12, etc. It is possible to insert a wire on the projection of the positions given. It is also possible to insert a half-pin using part of any recommended position. Where there is no second (symmetrically located) position, a halfpin only should be used. More detailed information about a choice of transosseous elements is presented in section 1.11. Near to the images of recommended transosseous elements are placed their MUDEF designations. As the angle of insertion of a half-pin is defined by the requirements for optimum biomechanics in a particular clinical situation, in the submitted schemes actual digital values of the angles of insertion of the half-pins are not specified.

The acupuncture points and classic meridians are shown in Fig. 1.9.1. The upper extremities are crossed by the following meridians: lung (P), large intestine (GI), triple energizer (TR), small intestine (IG), heart (C) and pericardium (MC). The lower extremities are crossed by the following meridians: stomach (E), liver (F), spleen (Rp), kidneys (R), bladder (V) and gallbladder (VB). In the atlas the projections of the acupuncture points and meridians on the skin are shown. The zones where the levels are crossed by the meridians are designated in the section diagrams according to the recommendations of Volkov et al. [80]. The coincidences of levels and the acupuncture points are designated according to the French transcription. Only the designations in letters correspond to the crossing of a level by a meridian.While identifying the safe positions and RPs, the projections of acupuncture points and meridians are not shown because the meaning of a transosseous element passing through a reﬂex zone is still a matter of controversy [80–85]. The diagrams shown in the atlas are oriented in the anatomical-topographical norm. Prior to transosseous element insertion, the elimination of severe displacement of bone fragments and restoration of limb axis are required in order to allow correct placement of fixation elements. In cases of angular deformity,shortening,or dysplasia of the extremity, the ability to define the contraindicated positions is limited by adjunctive studies such as computerized tomography, MRI, and angiography.

1.9 Atlas for Insertion of Transosseous Element Reference Positions

Fig. 1.9.1a,b. Diagrams of meridians according to Luvsan [79]

39

40

1.9.1

1 General Aspects of External Fixation

Upper arm1

The figures show sections through the upper arm at each of the principal levels I–VIII of the upper arm. In the anatomic functional sections of the upper arm the thick → arrows designate the positions at which displacement of soft tissues is minimal for all movements of the shoulder and elbow joints: ﬂexion, extension, abduction, rotation. The → thin arrows designate the positions at which displacement of soft tissues is minimal for most of the movements: ﬂexion, extension, abduction. Of 93 positions, 60 (64.5%) are safe positions as defined according to MUDEF (positions 2,3 and 4 at level I are not considered due to anatomic constraints). In the humerus there are 29 RPs (31.2%) for transosseous element insertion. The insertion of K-wires is prudent and safe only at levels III, IV, V, VII, and VIII. On the humerus there are three Yin meridians with a centrifugal direction of energy motion: the lung meridian (P), the heart meridian (C) and the pericardium meridian (MC). There are three Yang meridians with a centripetal direction of energy motion: the large bowel meridian (GI), the triple energizer meridian (TR), and the small bowel meridian (IG). The meridians on the humerus are represented by 22 active points.

1

The material presented was prepared in collaboration with R. E. Inyushin.

1.9 Atlas for Insertion of Transosseous Element Reference Positions

41

Contraindicated positions: 3 and 4 Safe positions: 1, 5, 6, 7, 8, 9, 10, 11 and 12 Reference positions: 8, 9, 10 and 11 Comments Only console transosseous elements can be used in the projection of positions 8, 9 and 10. The use of positions 8, 10 and 11 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue with shoulder joint motion.

Level I

Transosseous elements recommended for use at the humeral level I: I,8; I,10 and I,11.

42

1 General Aspects of External Fixation

Contraindicated positions: 1, 2, 3 and 4 Safe positions: 5, 6, 7, 8, 9, 10, 11 and 12 Reference positions: 8, 9, 10 and 11 Comments Only console transosseous elements can be used in the projection of positions 7, 8, 9 and 10. The use of positions 8, 10 and 11 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the shoulder during motion of the glenohumeral joint.

Level II

Transosseous elements recommended for use at the humeral level II: II,8; II,9; II,10 and II,11.

1.9 Atlas for Insertion of Transosseous Element Reference Positions

43

Contraindicated positions: 1, 3, 4 and 5 Safe positions: 2, 6, 7, 8, 9, 10, 11 and 12 Reference positions: 9, 10 and 11 Comments Only console transosseous elements can be used in the projection of positions 7, 8, 9, 10 and 11. The radial nerve lies close to the humerus in the projection of positions 4 and 5. Console transosseous elements at positions 10 and 11 should therefore penetrate only the anterolateral cortical plate. The use of positions 9, 10 and 11 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the shoulder during motion of the glenohumeral and (to a lesser degree) the elbow joints. Level III

Transosseous elements recommended for use at the humeral level III: III,9; III,10 and III,11.

44

1 General Aspects of External Fixation

Contraindicated positions: 1, 3, 5, 6 and 7 Safe positions: 2, 4, 8, 9, 10, 11 and 12 Reference positions: 8, 9, 10 and 11 Comments Only console transosseous elements can be used in the projection of positions 9, 11 and 12. Because of the close proximity of the radial nerve to the humerus in the projection of positions 5 and 6, it is necessary to use console transosseous elements in the projection of positions 11 and 12 that penetrate only the anterior cortical plate. The use of positions 8, 9, 10 and 11 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the shoulder with motion of the adjacent joints. Level IV

Transosseous elements recommended for use at the humeral level IV: IV,8; IV,9; IV,10 and IV,11.

1.9 Atlas for Insertion of Transosseous Element Reference Positions

45

Contraindicated positions: 1, 2, 3, 7, 8 and 9 Safe positions: 4, 5, 6, 10, 11 and 12 Reference positions: 4, 5, 6 and 10 Comments The use of positions 4, 10 and 11 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the shoulder with motion in the adjacent joints.

Level V

Transosseous elements recommended for use at the humeral level V: V,4; V,5; V,6; V,10 and V,4-10.

46

1 General Aspects of External Fixation

Contraindicated positions: 2, 3, 9, 10 and 12 Safe positions: 1, 4, 5, 6, 7, 8 and 11 Reference positions: 4, 7 and 8 Comments Only console transosseous elements can be used in the projection of positions 4, 6 and 8. The use of positions 4, 7 and 8 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the shoulder with motion in the glenohumeral and (to a lesser degree) the elbow joints.

Level VI

Transosseous elements recommended for use at the humeral level VI: VI,4; VI,7 and VI,8.

1.9 Atlas for Insertion of Transosseous Element Reference Positions

47

Contraindicated positions: 2, 4, 10, 11 and 12 Safe positions: 1, 3, 5, 6, 7, 8 and 9 Reference positions: 3, 8 and 9 Comments Only console transosseous elements can be used in the projection of positions 5, 6 and 8. The use of positions 3, 8 and 9 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the shoulder with motion of the elbow joint.

Level VII

Transosseous elements recommended for use at the humeral levelVII:VII,3;VII,8;VII,9 and VII,3-9.

48

1 General Aspects of External Fixation

Contraindicated positions: 1, 2, 11 and 12 Safe positions: 3, 4, 5, 6, 7, 8, 9 and 10 Reference positions: 3, 4, 8 and 9 Comments Positions 5, 6 and 7 are conditionally safe because using transosseous elements in the olecranon will lead to limitation of elbow joint motion. Only console transosseous elements can be used in the projection of position 8. The application of positions 3, 4, 8 and 9 is best at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the shoulder with motion of the elbow joint. Level VIII

Transosseous elements recommended for use at the humeral level VIII: VIII,3; VIII,4; VIII,8; VIII,9 and VIII,3-9.

1.9 Atlas for Insertion of Transosseous Element Reference Positions

1.9.2

Ulna2

The figures show sections through the forearm at each of the principal levels I–VIII relative to the ulna in the mid-position (between pronation and supination, see pages 50–57), in supination (see pages 58–65) and in pronation (see pages 66–73), respectively. Our studies have demonstrated that physiological movements in the radioulnar joints (forearm rotation) do not exceed 12–140◦ (65±5◦ ) for supination and pronation. Evaluation at level VIII showed that the ulna and radius are placed strictly in the frontal plane. The noted position of the radius relative to the ulna is shown in the diagrams. We determined that 77% of the positions are safe positions for insertion of transosseous elements. To provide functional rotation alone during fixation treatment, there are only 26 RPs (30%). They are indicated by arrows −→.The positions that provide only free ﬂexion and extension in the elbow and radiocarpal joints (33% of the positions) are indicated by thickening of the projection lines ——. K-wires inserted at six distal levels (the goal of which is to change the spatial orientation of the bone fragments) must later be changed to half-pins inserted in the orientation; these are indicated by arrows −→. On the forearm there are three Yin meridians with a centrifugal direction of energy motion: the lung meridian (P), the heart meridian (C) and the pericardium meridian (MC). There are three Yang meridians with a centripetal direction of energy motion: the bowel meridian (GI), the triple energizer meridian (TR) and the intestinal meridian (IG).The meridians on the forearm are represented by 27 active points. In accordance with MUDEF, transosseous elements in the radius are enclosed in round brackets. Note that (VIII,12-6)VIII,12-6 and VIII,6-12(VIII,6-12) designate the same K-wire inserted at level VIII through both bones,but in the first case the wire is inserted from the radial side and in the second it is inserted from the ulnar side.

2

The material presented was prepared in collaboration with P. N. Kulesh.

49

50

1 General Aspects of External Fixation

1.9.2.1 Mid-position Contraindicated positions: 1, 3 and 12 Safe positions: 2, 4, 5, 6, 7, 8, 9, 10 and 11 Reference positions: 4, 5, 6, 7, 8, 9 and 10 Reference positions with safe rotation: 4, 5, 6, 7, 8, 9 and 10 Comments Only console transosseous elements can be used in the projection of positions 6, 7 and 9. The use of positions 4, 5, 6, 7, 8, 9 and 10 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the ulna with motion of the elbow and radioulnar joints. Level I

Transosseous elements recommended for use at ulnar level I: I,4; I,5; I,5(I,5); I,6; I,7; I,8; I,9; I,10 and I,4-10.

1.9 Atlas for Insertion of Transosseous Element Reference Positions

51

Contraindicated positions: 1, 2, 3 and 12 Safe positions: 4, 5, 6, 7, 8, 9, 10 and 11 Reference positions: 4, 5, 6, 7, 8, 9 and 10 Reference positions with safe rotation: 4, 5, 6, 7, 8, 9 and 10 Comments Only console transosseous elements can be used in the projection of positions 6, 7, 8 and 9. The use of positions 4, 5, 6, 7, 8, 9 and 10 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the ulna with motion of the elbow and radioulnar joints. Level II (Ulna, mid-position)

The transosseous elements recommended for use at ulnar level II: II,4; II,5; II,6; II,6(II,6); II,7; II,8; II,9; II,10 and II,4-10.

52

1 General Aspects of External Fixation

Contraindicated positions: 1 and 2 Safe positions: 3, 4, 5, 6, 7, 8, 9, 10, 11 and 12 Reference positions: 3, 4, 5, 6, 7, 8, 9, 10, 11 and 12 Reference positions with safe rotation: 4, 5, 6, 7 and 8 Comments Only console transosseous elements can be used in the projection of positions 7 and 8. The use of positions 4, 5, 6, 7 and 8 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the ulna with motion of the elbow and radioulnar joints. Insertion of transosseous elements in the projection of positions 3, 9, 10, 11 and 12 will limit forearm rotation.

Level III (Ulna, mid-position)

Transosseous elements recommended for use at ulnar level III: III,3; III,4; III,5; III,6; III,6(III,6); III,7; III,8; III,9; III,10; III,11; III,3-9; III,4-10; III,5-11; III,6-12(III,6-12) and (III,12)III,12.

1.9 Atlas for Insertion of Transosseous Element Reference Positions

53

Contraindicated positions: 1, 2 and 3 Safe positions: 4, 5, 6, 7, 8, 9, 10, 11 and 12 Reference positions: 4, 5, 6, 7, 8, 9 and 10 Reference positions with safe rotation: 5, 6 and 7 Comments Only console transosseous elements can be used in the projection of positions 7, 8 and 9. The use of positions 5, 6 and 7 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the ulna with motion of the elbow and radioulnar joints on forearm rotation. Insertion of transosseous elements in the projection of positions 4, 8, 9 and 10 will limit forearm rotation. Level IV (Ulna, mid-position)

Transosseous elements recommended for use at ulnar level IV: IV,4; IV,5; IV,6; IV,6(IV,6); IV,7; IV,8; IV,9; IV,10 and IV,4-10.

54

1 General Aspects of External Fixation

Contraindicated positions: 1 and 3 Safe positions: 2, 4, 5, 6, 7, 8, 9, 10, 11 and 12 Reference positions: 5, 6, 7, 8, 9, 10, 11 and 12 Reference positions with safe rotation: 5, 6 and 7 Comments Only console transosseous elements can be used in the projection of positions 7 and 9. The use of positions 5, 6, 7 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the ulna with motion of the elbow and radioulnar joints on forearm rotation. Insertion of transosseous elements in the projection of positions 8, 9, 10, 11 and 12 will limit forearm rotation.

Level V (Ulna, mid-position)

Transosseous elements recommended for use at ulnar level V: V,5; V,5-11; V,6; V,6-12(V,6-12); V,6(V,6); V,7; V,8; V,9; V,10; V,11 and (V,12)V,12.

1.9 Atlas for Insertion of Transosseous Element Reference Positions

55

Contraindicated positions: 1 and 3 Safe positions: 2, 4, 5, 6, 7, 8, 9, 10, 11 and 12 Reference positions: 5, 6, 7, 8, 9, 10, 11 and 12 Reference positions with safe rotation: 5, 6, and 7 Comments Only console transosseous elements can be used in the projection of positions 7 and 9. The use of positions 5, 6 and 7 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the ulna with motion of the elbow and radioulnar joints on forearm rotation. Insertion of transosseous elements in the projection of positions 8, 9, 10, 11 and 12 will provide free ﬂexion and extension of the joints adjacent to the forearm, but will limit forearm rotation.

Level VI (Ulna, mid-position)

Transosseous elements recommended for use at ulnar level VI: VI,5; VI,5-11; VI,6; VI,6(VI,6); VI,612(VI,6-12); VI,7; VI,8; VI,9; VI,10; VI,11 and (VI,12)VI,12.

56

1 General Aspects of External Fixation

Contraindicated positions: 1 and 3 Safe positions: 2, 4, 5, 6, 7, 8, 9, 10, 11 and 12 Reference positions: 5, 6, 7, 8, 9, 10, 11 and 12 Reference positions with safe rotation: 6 and 7 Comments Only console transosseous elements can be used in the projection of positions 7 and 9. The use of positions 6 and 7 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the ulna with motion of the elbow and radioulnar joints on forearm rotation. Insertion of transosseous elements in the projection of positions 5, 8, 9, 10, 11 and 12 will provide free ﬂexion and extension in the radiocarpal joint, but will limit forearm rotation.

Level VII (Ulna, mid-position)

Transosseous elements recommended for use at ulnar level VII: VII,5; VII,5-11; VII,6; VII,6-12(VII,612); VII,6(VII,6); VII,7; VII,8; VII,9; VII,10; VII,11 and (VII,12)VII,12.

1.9 Atlas for Insertion of Transosseous Element Reference Positions

57

Contraindicated positions: 1, 2, 3 and 4 Safe positions: 5, 6, 7, 8, 9, 10, 11 and 12 Reference positions: 6, 7, 8, 11 and 12 Reference position with safe rotation: 6 Comments Only console transosseous elements can be used in the projection of positions 7, 8, 9 and 10. The use of position 6 is optimal at this level as the transosseous elements will minimally restrict displacement of soft tissue relative to the ulna with motion of the elbow and radioulnar joints on forearm rotation. Insertion of transosseous elements in the projection of positions 7, 8 and 12 will provide free ﬂexion and extension of the radiocarpal joint, but will limit forearm rotation.

Level VIII (Ulna, mid-position)

Transosseous elements recommended for use at ulnar level VIII: VIII,6; VIII,6-12(VIII,6-12); VIII,6(VIII,6); VIII,7; VIII,8 and (VIII,12)VIII,12.

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1 General Aspects of External Fixation

1.9.2.2 Supination Contraindicated positions: 1, 3 and 12 Safe positions: 2, 4, 5, 6, 7, 8, 9, 10 and 11 Reference positions: 4, 5, 6, 7, 8, 9 and 10 Reference positions with safe rotation: 4, 5, 6, 7, 8, 9 and 10 Comments Only console transosseous elements can be used in the projection of positions 6, 7 and 9. The use of positions 4, 5, 6, 7, 8, 9 and 10 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissues relative to the ulna with motion of the elbow and radioulnar joints. Level I

Transosseous elements recommended for use at ulnar level I: I,4; I,5; I,5(I,5); I,6; I,7; I,8; I,9; I,10 and I,4-10.

1.9 Atlas for Insertion of Transosseous Element Reference Positions

59

Contraindicated positions: 1, 2, 3 and 12 Safe positions: 4, 5, 6, 7, 8, 9, 10 and 11 Reference positions: 4, 5, 6, 7, 8, 9 and 10 Reference positions with safe rotation: 4, 5, 6, 7, 8, 9 and 10 Comments Only console transosseous elements can be used in the projection of positions 6, 7, 8 and 9. The use of positions 4, 5, 6, 7, 8, 9 and 10 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the ulna with motion of the elbow and radioulnar joints. Level II (Ulna, supination)

Transosseous elements recommended for use at ulnar level II: II,4; II,5; II,6; II,6(II,6); II,7; II,8; II,9; II,10 and II,4-10.

60

1 General Aspects of External Fixation

Contraindicated positions: 1, 2, 11 and 12 Safe positions: 3, 4, 5, 6, 7, 8, 9 and 10 Reference positions: 3, 4, 5, 6, 7, 8, 9 and 10 Reference positions with safe rotation: 4, 5, 6, 7 and 8 Comments Only console transosseous elements can be used in the projection of positions 5, 6, 7, and 8. The use of positions 4, 5, 6, 7 and 8 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the ulna with motion of the elbow and radioulnar joints. Insertion of transosseous elements in the projection of positions 3, 9 and 10 will limit forearm rotation.

Level III (Ulna, supination)

Transosseous elements recommended for use at ulnar level III: III,3; III,4; III,5; III,5(III,5); III,6; III,7; III,8; III,9; III,10; III,3-9 and III,4-10.

1.9 Atlas for Insertion of Transosseous Element Reference Positions

61

Contraindicated positions: 1, 2, 11 and 12 Safe positions: 3, 4, 5, 6, 7, 8, 9 and 10 Reference positions: 3, 4, 5, 6, 7, 8, 9 and 10 Reference positions with safe rotation: 5, 6 and 7 Comments Only console transosseous elements can be used in the projection of positions 5, 6, 7 and 8. The use of positions 5, 6 and 7 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the ulna with motion of the elbow and radioulnar joints. Insertion of transosseous elements in the projection of positions 3, 4, 8, 9 and 10 will limit forearm rotation. Level IV (Ulna, supination)

Transosseous elements recommended for use at ulnar level IV: IV,3; IV,4; IV,5; IV,5(IV,5); IV,6; IV,7; IV,8; IV,9; IV,10; IV,3-9 and IV,4-10.

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1 General Aspects of External Fixation

Contraindicated positions: 1, 2, 11 and 12 Safe positions: 3, 4, 5, 6, 7, 8, 9 and 10 Reference positions: 3, 4, 5, 6, 7, 8, 9 and 10 Reference position with safe rotation: 6 Comments Only console transosseous elements can be used in the projection of positions 5, 6, 7, and 8. The use of position 6 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the ulna with motion of the elbow and radioulnar joints on forearm rotation. Insertion of transosseous elements in the projection of positions 3, 4, 5, 7, 8, 9 and 10 will provide free ﬂexion and extension of the adjacent forearm joints, but will limit forearm rotation. Level V (Ulna, supination)

Transosseous elements recommended for use at ulnar level V: V,3; V,4; V,4(V,4); V,5; V,6; V,7; V,8; V,9; (V,10)V,10; V,3-9 and V,4-10(V,4-10).

1.9 Atlas for Insertion of Transosseous Element Reference Positions

63

Contraindicated positions: 1, 11 and 12 Safe positions: 2, 3, 4, 5, 6, 7, 8, 9 and 10 Reference positions: 3, 4, 5, 6, 7, 8, 9 and 10 Reference position with safe rotation: 6 Comments Only console transosseous elements can be used in the projection of positions 5, 6 and 7. The use of position 6 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the ulna with motion of the elbow and radioulnar joints on forearm rotation. Insertion of transosseous elements in the projection of positions 3, 4, 5, 7, 8, 9 and 10 will provide free ﬂexion and extension of the adjacent forearm joints, but will limit forearm rotation. Level VI (Ulna, supination)

Transosseous elements recommended for use at ulnar level VI: VI,3; VI,4; VI,4(VI,4); VI,5; VI,6; VI,7; VI,8; VI,9; (VI,10)VI,10; VI,3-9 and VI,4-10(VI,4-10).

64

1 General Aspects of External Fixation

Contraindicated positions: 1, 11 and 12 Safe positions: 2, 3, 4, 5, 6, 7, 8, 9 and 10 Reference positions: 2, 3, 4, 5, 6, 7, 8, 9 and 10 Reference position with safe rotation: 6 Comments Only console transosseous elements can be used in the projection of positions 5, 6 and 7. The use of position 6 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the ulna with motion of the elbow and radioulnar joints on forearm rotation. Insertion of transosseous elements in the projection of positions 2, 3, 4, 5, 7, 8, 9 and 10 will provide free ﬂexion and extension of the adjacent forearm joints, but will limit forearm rotation. Level VII (Ulna, supination)

Transosseous elements recommended for use at ulnar level VII: VII,2; VII,3; VII,4; VII,4(VII,4); VII,5; VII,6; VII,7; VII,8; VII,9; (VII,10)VII,10; VII,2-8; VII,3-9 and VII,4-10(VII,4-10).

1.9 Atlas for Insertion of Transosseous Element Reference Positions

65

Contraindicated positions: 1, 11 and 12 Safe positions: 2, 3, 4, 5, 6, 7, 8, 9 and 10 Reference positions: 2, 3, 4, 5, 6, 7, 8, 9 and 10 Reference position with safe rotation: 6 Comments Only console transosseous elements can be used in the projection of positions 5, 6 and 7. The use of position 6 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the ulna with motion of the elbow and radioulnar joints on forearm rotation. Insertion of transosseous elements in the projection of positions 2, 3, 4, 5, 7, 8, 9 and 10 will provide free ﬂexion and extension of the adjacent forearm joints, but will limit forearm rotation.

Level VIII (Ulna, supination)

Transosseous elements recommended for use at ulnar level VIII: VIII,2; VIII,3; VIII,4; VIII,4(VIII,4); VIII,5; VIII,6; VIII,7; VIII,8; VIII,9; (VIII,10)VIII,10; VIII,2-8; VIII,3-9 and VIII,4-10(VIII,4-10).

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1 General Aspects of External Fixation

1.9.2.3 Pronation Contraindicated positions: 1, 3, 12 Safe positions: 2, 4, 5, 6, 7, 8, 9, 10 and 11 Reference positions: 4, 5, 6, 7, 8, 9 and 10 Reference positions with safe rotation: 4, 5, 6, 7, 8, 9 and 10 Comments Only console transosseous elements can be used in the projection of positions 6, 7 and 9. The use of positions 4, 5, 6, 7, 8, 9 and 10 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the ulna with motion of the elbow and radioulnar joints. Level I

Transosseous elements recommended for use at ulnar level I: I,4; I,5; I,5(I,5); I,6; I,7; I,8; I,9; I,10 and I,4-10.

1.9 Atlas for Insertion of Transosseous Element Reference Positions

67

Contraindicated positions: 1, 2, 3 and 12 Safe positions: 4, 5, 6, 7, 8, 9, 10 and 11 Reference positions: 4, 5, 6, 7, 8, 9 and 10 Reference positions with safe rotation: 4, 5, 6, 7, 8, 9 and 10 Comments Only console transosseous elements can be used in the projection of positions 6, 7, 8 and 9. The use of positions 4, 5, 6, 7, 8, 9 and 10 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the ulna with motion of the elbow and radioulnar joints. Level II (Ulna, pronation)

Transosseous elements recommended for use at ulnar level II: II,4; II,5; II,6; II,6(II,6); II,7; II,8; II,9; II,10 and II,4-10.

68

1 General Aspects of External Fixation

Contraindicated positions: 1, 2 and 3 Safe positions: 4, 5, 6, 7, 8, 9, 10, 11 and 12 Reference positions: 4, 5, 6, 7, 8, 9 and 10 Reference positions with safe rotation: 4, 5, 6, 7, 8 and 9 Comments Only console transosseous elements can be used in the projection of positions 7, 8 and 9. The use of positions 4, 5, 6, 7, 8, and 9 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the ulna with motion of the elbow and radioulnar joints. Insertion of a transosseous element in the projection of position 10 will limit forearm rotation. Level III (Ulna, pronation)

Transosseous elements recommended for use at ulnar level III: III,4; III,5; III,6; III,7; III,7(III,7); III,8; III,9; III,10 and III,4-10.

1.9 Atlas for Insertion of Transosseous Element Reference Positions

69

Contraindicated positions: 1, 2 and 3 Safe positions: 4, 5, 6, 7, 8, 9, 10, 11 and 12 Reference positions: 4, 5, 6, 7, 8, 9, 10 and 11 Reference positions with safe rotation: 5, 6 and 7 Comments Only console transosseous elements can be used in the projection of positions 7, 8 and 9. The use of positions 5, 6 and 7 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the ulna with motion of the elbow and radiocarpal joints on forearm rotation. Insertion of transosseous elements in the projection of positions 4, 8, 9, 10 and 11 will limit forearm rotation. Level IV (Ulna, pronation)

Transosseous elements recommended for use at ulnar level IV: IV,4; IV,5; IV,6; IV,7; IV,7(IV,7); IV,8; IV,9; IV,10; IV,11; IV,4-10 and IV,5-11.

70

1 General Aspects of External Fixation

Contraindicated positions: 2, 3 and 4 Safe positions: 1, 5, 6, 7, 8, 9, 10, 11 and 12 Reference positions: 1, 5, 6, 7, 8, 9 and 10 Reference position with safe rotation: 6 Comments Only console transosseous elements can be used in the projection of positions 8, 9 and 10. The use of position 6 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the ulna with motion of the elbow and radiocarpal joints on forearm rotation. Insertion of transosseous elements in the projection of positions 1, 5, 7, 8, 9 and 10 will limit forearm rotation.

Level V (Ulna, pronation)

Transosseous elements recommended for use at ulnar level V: (V,1)V,1; V,5; V,6; V,7; V,7-1(V,7-1); V,7(V,7); V,8; V,9 and V,10.

1.9 Atlas for Insertion of Transosseous Element Reference Positions

71

Contraindicated positions: 2, 3 and 4 Safe positions: 1, 5, 6, 7, 8, 9, 10, 11 and 12 Reference positions: 1, 5, 6, 7, 8, 9 and 10 Reference position with safe rotation: 6 Comments Only console transosseous elements can be used in the projection of positions 8, 9 and 10. The use of position 6 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the ulna with motion of the elbow and radiocarpal joints on forearm rotation. Insertion of transosseous elements in the projection of positions 1, 5, 7, 8, 9, and 10 will provide free ﬂexion and extension of adjacent forearm joints, but will limit forearm rotation.

Level VI (Ulna, pronation)

Transosseous elements recommended for use at ulnar level VI: (VI,1)VI,1; VI,5; VI,6; VI,7; VI,71(VI,7-1); VI,7(VI,7); VI,8; VI,9 and VI,10.

72

1 General Aspects of External Fixation

Contraindicated positions: 3 and 4 Safe positions: 1, 2, 5, 6, 7, 8, 9, 10, 11 and 12 Reference positions: 2, 5, 6, 7, 8, 9 and 10 Reference position with safe rotation: 6 Comments Only console transosseous elements can be used in the projection of positions 9 and 10. The use of position 6 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the ulna with motion of the elbow and radiocarpal joints on forearm rotation. Insertion of transosseous elements in the projection of positions 2, 5, 7, 8, 9 and 10 will provide free ﬂexion and extension of adjacent forearm joints, but will limit forearm rotation.

Level VII (Ulna, pronation)

Transosseous elements recommended for use at ulnar level VII: (VII,2)VII,2; VII,5; VII,6; VII,7; VII,8; VII,8-2(VII,8-2); VII,8(VII,8); VII,9 and VII,10.

1.9 Atlas for Insertion of Transosseous Element Reference Positions

73

Contraindicated positions: 3, 4 and 5 Safe positions: 1, 2, 6, 7, 8, 9, 10, 11 and 12 Reference positions: 2, 6, 7, 8, 9 and 10 Reference position with safe rotation: 6 Comments Only console transosseous elements can be used in the projection of positions 9, 10 and 11. The use of position 6 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the ulna with motion of the elbow and radiocarpal joints on forearm rotation. Insertion of transosseous elements in the projection of positions 2, 7, 8, 9 and 10 will provide free ﬂexion and extension of adjacent forearm joints, but will limit forearm rotation.

Level VIII (Ulna, pronation)

Transosseous elements recommended for use at ulnar level VIII: (VIII,2)VIII,2; VIII,6; VIII,7; VIII,8; VIII,8-2(VIII,8-2); VIII,8(VIII,8); VIII,9 and VIII,10.

74

1.9.3

1 General Aspects of External Fixation

Radius3

The figures show sections through the forearm at each of the principal levels I–VIII relative to the radius in the mid-position (see between pronation and supination, pages 75–82), in supination (see pages 83–90) and in pronation (see pages 91–98), respectively. On the anatomic functional cross sections of the forearm, the arrows −→ indicate only the safe positions where, following K-wire or half-pin insertion at that location, we can expect complete restoration of rotational forearm function during the fixation period. Thickening of the projection lines —— indicates that the insertion of transosseous elements into the designated locations will only allow the early restoration of ﬂexion and extension of both the elbow and wrist joints. Of the 96 positions, 67 (68%) are safe positions as defined according to MUDEF. Studies of soft tissue movements relative to the radius during supination and pronation of the forearm have demonstrated that safe application of external fixation elements to the radius is impossible without disturbing rotational function. Insertion of transosseous elements in this context is possible only at levels VII and VIII in the projections of 8 positions (8% of possible positions). These are indicated by → arrows. However, there are positions that allow rotational function during the fixation period to be partially restored (Table 1.3). The RPs that allow only ﬂexion and extension of the elbow and radiocarpal joints and partial rotational function (47% of total positions) are indicated by thickening of the projection lines. On the forearm there are three Yin meridians with a centrifugal direction of energy motion: the lung meridian (P), the heart meridian (C) and the pericardium meridian (MC). There are three Yang meridians with a

centripetal direction of energy motion: the large bowel meridian (GI), the triple energizer meridian (TR), and the small bowel meridian (IG). The meridians on the forearm are represented by 27 active points. According to MUDEF, those transosseous elements applied to the radius are enclosed in round brackets. Note that (VIII,12-6)VIII,12-6 and VIII,6-12(VIII,6-12) designate the same K-wire inserted atVIII level through both bones,but in the first case the wire is inserted from the radial side, and in second it is inserted from the ulnar side.

Table 1.3. Positions that allow forearm rotation Level

3

Positions that allow partial rotation Supination

10◦ , pronation 10◦

Supination 30◦ , pronation 25◦

Positions that allow complete rotation –

I

8

–

II

–

8

–

III

9, 10, 11, 12

1, 8

–

IV

8, 9, 10

1, 11, 12

–

V

8, 9

10, 11, 12

–

VI

–

1, 8, 9, 10, 11, 12

–

VII

–

10

1, 11, 12

VIII

–

10, 11

1, 12

The material presented was prepared in collaboration with P.N. Kulesh.

1.9 Atlas for Insertion of Transosseous Element Reference Positions

75

1.9.3.1 Mid-position Contraindicated positions: 1, 2, 3, 4 and 12 Safe positions: 5, 6, 7, 8, 9, 10 and 11 Reference positions: 5, 6, 7 and 8 Comments Only console transosseous elements can be used in the projection of positions 6, 7, 8, 9 and 10. The use of positions 5, 6, 7 and 8 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the radius with the full range of motion of the elbow joint. Level I

Transosseous elements recommended for use at radial level I: I,5(I,5); (I,6); (I,7) and (I,8).

76

1 General Aspects of External Fixation

Contraindicated positions: 1, 2, 3, 4, 11 and 12 Safe positions: 5, 6, 7, 8, 9 and 10 Reference positions: 5, 6, 7 and 8 Comments Only console transosseous elements can be used in the projection of positions 5, 6, 7, 8, 9 and 10. Because of the close proximity of the radial nerve to the radius in the projection of positions 11 and 12, it is necessary to use console transosseous elements in the projection of positions 5 and 6 that penetrate only the posterior cortical plate. The use of positions 5, 6, 7 and 8 is optimal at this level because the transosseous elements will only minimally restrict displacement of the soft tissue relative to the radius with the full range of motion of the elbow joint.

Level II (Radius, mid-position)

Transosseous elements recommended for use at radial level II: (II,5); II,6(II,6); (II,7) and (II,8).

1.9 Atlas for Insertion of Transosseous Element Reference Positions

77

Contraindicated positions: 2, 3 and 4 Safe positions: 1, 5, 6, 7, 8, 9, 10, 11 and 12 Reference positions: 1, 5, 6, 7, 8, 9, 10, 11 and 12 Comments Only console transosseous elements can be used in positions 8, 9 and 10. The use of positions 1, 5, 6, 7, 8, 9, 10, 11 and 12 is optimal at this level because the transosseous elements will not restrict displacement of the soft tissue relative to the radius during motion of elbow joint.

Level III (Radius, mid-position)

Transosseous elements recommended for use at radial level III: (III,1); (III,1-7); (III,5); (III,5-11); III,6(III,6); III,6-12(III,6-12); (III,7); (III,8); (III,9); (III,10); (III,11) and (III,12).

78

1 General Aspects of External Fixation

Contraindicated positions: 2, 3, 4 and 5 Safe positions: 1, 6, 7, 8, 9, 10, 11 and 12 Reference positions: 1, 6, 7, 8, 9, 10, 11 and 12 Comments Only console transosseous elements can be used in the projection of positions 8, 9, 10 and 11. The use of positions 1, 6, 7, 8, 9, 10, 11 and 12 is optimal at this level because the transosseous elements will not restrict displacement of the soft tissue relative to the radius with motion of the elbow and radiocarpal joints. Level IV (Radius, mid-position)

Transosseous elements recommended for use at radial level IV: (IV,1); (IV,1-7); IV,6(IV,6); IV,6-12(IV,612); (IV,7); (IV,8); (IV,9); (IV,10); (IV,11); (IV,12) and (IV,12)IV,12.

1.9 Atlas for Insertion of Transosseous Element Reference Positions

79

Contraindicated positions: 2, 3, 4 and 5 Safe positions: 1, 6, 7, 8, 9, 10, 11 and 12 Reference positions: 1, 6, 7, 8, 9, 10, 11 and 12 Comments Only console transosseous elements can be used in the projection of positions 8, 9, 10 and 11. The use of positions 1, 6, 7, 8, 9, 10, 11 and 12 is optimal at this level because the transosseous elements will not restrict displacement of the soft tissue relative to the radius with motion of the elbow and radiocarpal joints. Level V (Radius, mid-position)

Transosseous elements recommended for use at radial level V: (V,1); (V,l-7); V,6(V,6); V,6-12(V,6-12); (V,7); (V,8); (V,9); (V,10); (V,11); (V,12) and (V,12)V,12.

80

1 General Aspects of External Fixation

Contraindicated positions: 2, 3, 4 and 5 Safe positions: 1, 6, 7, 8, 9, 10, 11 and 12 Reference positions: 1, 6, 7, 8, 9, 10, 11 and 12 Comments Only console transosseous elements can be used in the projection of positions 8, 9, 10 and 11. The use of positions 1, 6, 7, 8, 9, 10, 11 and 12 is optimal at this level because the transosseous elements will not restrict displacement of the soft tissue relative to the radius with motion of the elbow and radiocarpal joints. Level VI (Radius, mid-position)

Transosseous elements recommended for use at radial level VI: (VI,1); (VI,l-7); VI,6(VI,6); VI,612(VI,6-12); (VI,7); (VI,8); (VI,9); (VI,10); (VI,11); (VI,12) and (VI,12)VI,12.

1.9 Atlas for Insertion of Transosseous Element Reference Positions

81

Contraindicated positions: 2, 3 and 5 Safe positions: 1, 4, 6, 7, 8, 9, 10, 11 and 12 Reference positions: 1, 6, 7, 10, 11 and 12 Reference positions with safe rotation: 11 and 12 Comments Only console transosseous elements can be used in the projection of positions 8, 9 and 11. The application of positions 11 and 12 is optimal at this level, as the transosseous elements will not impede the soft tissue movements relative to the radius with range of motion in the elbow and radiocarpal joints. Insertion of transosseous elements in the projection of positions 1, 6, 7 and 10 will, however, limit forearm rotation. Level VII (Radius, mid-position)

Transosseous elements recommended for use at radial level VII: (VII,1); (VII,1-7); VII,6(VII,6); VII,612(VII,6-12); (VII,7); (VII,10); (VII,11); (VII,12) and (VII,12)VII,12.

82

1 General Aspects of External Fixation

Contraindicated positions: 2, 3 and 5 Safe positions: 1, 4, 6, 7, 8, 9, 10, 11 and 12 Reference positions: 1, 6, 10, 11 and 12 Reference positions with safe rotation: 1 and 12 Comments Only console transosseous elements can be used in the projection of positions 8, 9 and 11. The use of positions 1 and 12 is optimal at this level because the transosseous elements will not restrict displacement of the soft tissue relative to the radius with motion of the elbow and radiocarpal joints. Insertion of transosseous elements in the projection of positions 6, 10 and 11 will limit forearm rotation. Level VIII (Radius, mid-position)

Transosseous elements recommended for use at radial level VIII: (VIII,1); VIII,6(VIII,6); VIII,612(VIII,6-12); (VIII,10); (VIII,11); (VIII,12) and (VIII,12)VIII,12.

1.9 Atlas for Insertion of Transosseous Element Reference Positions

83

1.9.3.2 Supination Contraindicated positions: 1, 2, 3 and 4 Safe positions: 5, 6, 7, 8, 9, 10, 11 and 12 Reference positions: 5, 6, 7, 8 and 9 Comments

Level I

Only console transosseous elements can be used in the projection of positions 7,8,9 and 10.Because of the close proximity of the radial nerve to the radius in the projection of position 1,it is necessary to use console transosseous elements in the projection of position 7 that penetrate only the posterolateral cortical plate. The use of positions 5, 6, 7, 8, 9 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the radius with motion of the elbow joint.

Transosseous elements recommended for use at radial level I: I,5(I,5); (I,6); (I,7); (I,8) and (I,9).

84

1 General Aspects of External Fixation

Contraindicated positions: 1, 2, 3, 4 and 12 Safe positions: 5, 6, 7, 8, 9, 10 and 11 Reference positions: 5, 6, 7, 8 and 9 Comments Only console transosseous elements can be used in the projection of positions 6, 7, 8, 9 and 10. Because of the close proximity of the radial nerve to the radius in the projection of position 12, it is necessary to use console transosseous elements in the projection of position 6 that penetrate only the posterior cortical plate. The use of positions 5, 6, 7, 8, 9 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the radius with motion of the elbow joint.

Level II (Radius, supination)

Transosseous elements recommended for use at radial level II: II,5(II,5); (II,6); (II,7); (II,8) and (II,9).

1.9 Atlas for Insertion of Transosseous Element Reference Positions

85

Contraindicated positions: 1, 2, 3, 11 and 12 Safe positions: 4, 5, 6, 7, 8, 9 and 10 Reference positions: 5, 6, 7, 8, 9 and 10 Comments Only console transosseous elements can be used in the projection of positions 5, 6, 7, 8 and 9. The use of positions 5, 6, 7, 8, 9 and 10 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the radius with motion of the elbow joint. Level III (Radius, supination)

Transosseous elements recommended for use at radial level III: III,5(III,5); (III,6); (III,7); (III,8), (III,9) and (III,10).

86

1 General Aspects of External Fixation

Contraindicated positions: 1, 2 and 3 Safe positions: 4, 5, 6, 7, 8, 9, 10, 11 and 12 Reference positions: 4, 5, 6, 7, 8, 9, 10 and 11 Comments Only console transosseous elements can be used in the projection of positions 7, 8 and 9. The use of positions 4, 5, 6, 7, 8, 9, 10 and 11 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the radius with motion of the elbow joint.

Level IV (Radius, supination)

Transosseous elements recommended for use at radial level IV: (IV,4); (IV,5); (IV,6); (IV,7); (IV,8); (IV,9); (IV,10); (IV,11); (IV,10-4)IV,10-4 and (IV,11-5).

1.9 Atlas for Insertion of Transosseous Element Reference Positions

87

Contraindicated positions: 2, 3, 11 and 12 Safe positions: 1, 4, 5, 6, 7, 8, 9 and 10 Reference positions: 1, 4, 5, 6, 7, 8, 9 and 10 Comments Only console transosseous elements can be used in the projection of positions 5, 6, 7, 8 and 9. The use of positions 1, 4, 5, 6, 7, 8, 9 and 10 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the radius with motion of the elbow and radiocarpal joints. Level V (Radius, supination)

Transosseous elements recommended for use at radial level V: (V,l); V,4(V,4); (V,5); (V,6); (V,7); (V,8); (V,9); (V,10); (V,10)V,10; (V,1-7) and (V,10-4)V,10-4.

88

1 General Aspects of External Fixation

Contraindicated positions: 1, 2, 3, 11 and 12 Safe positions: 4, 5, 6, 7, 8, 9 and 10 Reference positions: 4, 5, 6, 7, 8, 9 and 10 Comments Only console transosseous elements can be used in the projection of positions 5, 6, 7, 8 and 9. The use of positions 4, 5, 6, 7, 8, 9 and 10 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the radius with motion of the radiocarpal joint. Level VI (Radius, supination)

Transosseous elements recommended for use at radial level VI: VI,4(VI,4); (VI,5); (VI,6); (VI,7); (VI,8); (VI,9); (VI,10); (VI,10)VI,10 and VI,4-10(VI,4-10).

1.9 Atlas for Insertion of Transosseous Element Reference Positions

89

Contraindicated positions: 1, 2, 3 and 12 Safe positions: 4, 5, 6, 7, 8, 9, 10 and 11 Reference positions: 4, 5, 7, 8, 9, 10 and 11 Reference positions with safe rotation: 7, 8, 9, 10 and 11 Comments Only console transosseous elements can be used in the projection of positions 6, 7, 8 and 9. The use of positions 7, 8, 9, 10 and 11 is optimal at this level, because the transosseous elements will minimally restrict displacement of the soft tissue relative to the radius with motion of the radiocarpal and radioulnar joints. Insertion of transosseous elements in the projection of positions 4 and 5 will limit forearm rotation. Level VII (Radius, supination)

Transosseous elements recommended for use at radial level VII: VII,4(VII,4); (VII,5); (VII,7); (VII,8); (VII,9); (VII,10); (VII,10)VII,10; (VII,11); (VII,10-4)VII,10-4 and (VII,5-11).

90

1 General Aspects of External Fixation

Contraindicated positions: 1, 2, 3 and 12 Safe positions: 4, 5, 6, 7, 8, 9, 10 and 11 Reference positions: 4, 5, 8, 9 and 10 Reference positions with safe rotation: 8, 9 and 10 Comments Only console transosseous elements can be used in the projection of positions 6, 7, 8 and 9. The use of positions 8, 9 and 10 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the radius with motion of the radiocarpal and radioulnar joints. Insertion of transosseous elements in the projection of positions 4 and 5 will limit forearm rotation. Level VIII (Radius, supination)

Transosseous elements recommended for use at radial level VIII: VIII,4(VIII,4); (VIII,5); (VIII,8); (VIII,9); (VIII,10); (VIII,10)VIII,10 and (VIII,10-4)VIII,10-4.

1.9 Atlas for Insertion of Transosseous Element Reference Positions

91

1.9.3.3 Pronation Contraindicated positions: 1, 2, 3 and 4 Safe positions: 5, 6, 7, 8, 9, 10, 11 and 12 Reference positions: 5, 6, 7, 8 and 9 Comments

Level I

Only console transosseous elements can be used in the projection of positions 7,8,9,10.Because of the close proximity of the radial nerve to the radius in the projection of position 1, it is necessary to use console transosseous elements in the projection of position 7 that penetrate only the posterolateral cortical plate. The use of positions 5, 7, 8, 9 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the radius with motion of the elbow joint.

Transosseous elements recommended for use at radial level I: I,5(I,5); (I,6); (I,7); (I,8) and (I,9).

92

1 General Aspects of External Fixation

Contraindicated positions: 1, 2, 3, 4, 11 and 12 Safe positions: 5, 6, 7, 8, 9 and 10 Reference positions: 5, 6, 7, 8 and 9 Comments Only console transosseous elements can be used in the projection of positions 5, 6, 7, 8, 9, 10. Because of the close proximity of the radial nerve to the radius in the projection of positions 11 and 12, it is necessary to use console transosseous elements in the projection of positions 5 and 6 that penetrate only the posterior cortical plate. The use of positions 5, 6, 7, 8, 9 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the radius with motion of the elbow joint.

Level II (Radius, pronation)

Transosseous elements recommended for use at radial level I: (II,5); II,6(II,6); (II,7); (II,8) and (II,9).

1.9 Atlas for Insertion of Transosseous Element Reference Positions

93

Contraindicated positions: 1, 2, 3, 4 and 5 Safe positions: 6, 7, 8, 9, 10, 11 and 12 Reference positions: 6, 7, 8 and 9 Comments Only console transosseous elements can be used in the projection of positions 7, 8, 9, 10 and 11. The use of positions 6, 7, 8, 9 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the radius with motion of the elbow joint.

Level III (Radius, pronation)

Transosseous elements recommended for use at radial level I: (III,6); III,7 (III,7); (III,8) and (III,9).

94

1 General Aspects of External Fixation

Contraindicated positions: 1, 2, 3, 4 and 5 Safe positions: 6, 7, 8, 9, 10, 11 and 12 Reference positions: 6, 7, 8, 9 and 10 Comments Only console transosseous elements can be used in the projection of positions 6, 7, 8, 9, 10 and 11. The use of positions 6, 7, 8, 9, 10 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the radius with motion of the elbow joint.

Level IV (Radius, pronation)

Transosseous elements recommended for use at radial level IV: (IV,6); IV,7(IV,7); (IV,8); (IV,9) and (IV,10).

1.9 Atlas for Insertion of Transosseous Element Reference Positions

95

Contraindicated positions: 4, 5 and 6 Safe positions: 1, 2, 3, 7, 8, 9, 10, 11 and 12 Reference positions: 1, 2, 3, 7, 8, 9, 10, 11 and 12 Comments Only console transosseous elements can be used in the projection of positions 10, 11 and 12. The use of positions 1, 2, 3, 7, 8, 9, 10, 11, 12 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the radius with motion of the elbow and radiocarpal joints. Level V (Radius, pronation)

Transosseous elements recommended for use at radial level V: (V,1); (V,1)V,1; (V,1-7) V,1-7; (V,2); (V,2-8); (V,3); (V,3-9); V,7(V,7); (V,8); (V,9); (V,10); (V,11) and (V,12).

96

1 General Aspects of External Fixation

Contraindicated positions: 4, 5 and 6 Safe positions: 1, 2, 3, 7, 8, 9, 10, 11 and 12 Reference positions: 1, 2, 3, 7, 8, 9, 10 and 11 Comments Only console transosseous elements can be used in the projection of positions 10, 11 and 12. The use of positions 1, 2, 3, 7, 8, 9, 10 and 11 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the radius with motion of the radiocarpal joint. Level VI (Radius, pronation)

Transosseous elements recommended for use at radial level VI: (VI,1); (VI,1)VI,1; (VI,l-7)VI,l-7; (VI,2); (VI,2-8); (VI,3); (VI,3-9); VI,7(VI,7); (VI,8): (VI,9); (VI,10) and (VI,11).

1.9 Atlas for Insertion of Transosseous Element Reference Positions

97

Contraindicated positions: 4, 5 and 6 Safe positions: 1, 2, 3, 7, 8, 9, 10, 11 and 12 Reference positions: 1, 2, 3, 8, 9 and 10 Reference positions with safe rotation: 1, 2 and 3 Comments Only console transosseous elements can be used in the projection of positions 10, 11 and 12. The use of positions 1, 2 and 3 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the radius with motion of the radiocarpal and radioulnar joints. Insertion of transosseous elements in the projection of positions 8, 9, 10 will limit forearm rotation. Level VII (Radius, pronation)

Transosseous elements recommended for use at radial level VII: (VII,1); (VII,1)VII,1; (VII,2); (VII,2-8); (VII,3); (VII,3-9); (VII,8); (VII,9) and (VII,10).

98

1 General Aspects of External Fixation

Contraindicated positions: 4, 5, 6 and 7 Safe positions: 1, 2, 3, 8, 9, 10, 11 and 12 Reference positions: 1, 2, 3, 8 and 9 Reference positions with safe rotation: 1, 2 and 3 Comments Only console transosseous elements can be used in the projection of positions 10, 11 and 12. The use of positions 1, 2 and 3 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the radius with motion of the radiocarpal and radioulnar joints. Insertion of transosseous elements in the projection of positions 8 and 9 will limit forearm rotation. Level VIII (Radius, pronation)

Transosseous elements recommended for use at radial level VIII: (VIII,1); (VIII,2); (VIII,2)VIII,2; (VIII,2-8)VIII,2-8; (VIII,3); (VIII,3-9); VIII,8(VIII,8) and (VIII,9).

1.9 Atlas for Insertion of Transosseous Element Reference Positions

1.9.4

Femur4

The figures show sections through the femur at each of the principal levels I–VIII. Of the 93 positions defined in accordance with MUDEF, positions 2, 3 and 4 at level I are eliminated due to obvious anatomical constraints, 68 (73%) are considered safe positions, and 28 (30%) are identified as RPs for transosseous element insertion. K-wires are used only at levels VI, VII and VIII. On the femur there are three Yin meridians with a centrifugal direction of energy motion pass: the liver meridian (F), the spleen meridian (Rp) and the kidney meridian (R). There are three Yang-meridians with a centripetal direction of energy motion: the stomach meridian (E), the bladder meridian (V), and the gallbladder meridian (VB). The meridians on the femur are represented by 21 active points.

4

The material presented was prepared in collaboration with M.V. Andrianov.

99

100

1 General Aspects of External Fixation

Contraindicated positions: 1 and 4 Safe positions: 5, 6, 7, 8, 9, 10, 11 and 12 Reference positions: 8, 9, 10 and 11 Comments Only console transosseous elements can be used in the projection of positions 7, 8, 9 and 10. The use of positions 8 and 9 is optimal at this level because the transosseous elements will not restrict displacement of the soft tissue relative to the femur with motion of the hip joint. In positions 10 and 11, subcutaneous fascial release should be carried out in a proximal direction (1–1.5 cm).

Level I

Transosseous elements recommended for use at femoral level I: I,8; I,9; I,10; I,11.

1.9 Atlas for Insertion of Transosseous Element Reference Positions

101

Contraindicated positions: 1, 2, 3 and 4 Safe positions: 5, 6, 7, 8, 9, 10, 11 and 12 Reference positions: 8, 9, 10 and 11 Comments Only console transosseous elements can be used in the projection of positions 7, 8, 9 and 10. The use of positions 8, 9, 10 and 11 is optimal at this level because the transosseous elements will not restrict displacement of the soft tissue relative to femur with motion of the hip joint. In positions 10 and 11, subcutaneous fascial release should be carried out in a proximal direction (1–1.5 cm).

Level II

Transosseous elements recommended for use at femoral level II: II,8; II,9; II,10 and II,11.

102

1 General Aspects of External Fixation

Contraindicated positions: 1, 2, 3, 4 and 5 Safe positions: 6, 7, 8, 9, 10, 11 and 12 Reference positions: 8, 9 and 10 Comments Only console transosseous elements can be used in the projection of positions 7, 8, 9, 10 and 11. The use of positions 9 and 10 is optimal at this level because the transosseous elements will not restrict displacement of the soft tissue relative to the femur with motion of the hip and (to a lesser degree) the knee joint. In positions 10 and 11 fascial release should be carried out in a proximal direction (1–1.5 cm). Level III

Transosseous elements recommended for use at femoral level III: III,8; III,9 and III,10.

1.9 Atlas for Insertion of Transosseous Element Reference Positions

103

Contraindicated positions: 2, 3, 4 and 5 Safe positions: 1, 6, 7, 8, 9, 10, 11 and 12 Reference positions: 8, 9 and 10 Comments Only console transosseous elements can be used in the projection of positions 8, 9, 10 and 11. The use of positions 8, 9 and 10 is optimal at this level because the transosseous elements will not restrict displacement of the soft tissue relative to the femur with motion of the adjacent joints.

Level IV

Transosseous elements recommended for use at femoral level IV: IV,8; IV,9 and IV,10.

104

1 General Aspects of External Fixation

Contraindicated positions: 3, 4 and 5 Safe positions: 1, 2, 6, 7, 8, 9, 10, 11 and 12 Reference positions: 8 and 9 Comments Only console transosseous elements can be used in the projection of positions 9, 10 and 11. The use of positions 8 and 9 is optimal at this level because the transosseous elements will not restrict displacement of the soft tissue relative to the femur with motion of the adjacent joints.

Level V

Transosseous elements recommended for use at femoral level V: V,8 and V,9.

1.9 Atlas for Insertion of Transosseous Element Reference Positions

105

Contraindicated positions: 4 and 5 Safe positions: 1, 2, 3, 6, 7, 8, 9, 10, 11 and 12 Reference positions: 3, 7, 8 and 9 Comments Only console transosseous elements can be used in the projection of positions 10 and 11. The use of positions 3, 7, 8 and 9 is optimal at this level because the transosseous elements will not restrict displacement of the soft tissue relative to the femur with motion of the knee and (to a lesser degree) the hip joints.

Level VI

Transosseous elements recommended for use at femoral level VI: VI,3; VI,7; VI,8; VI,9 and VI,3-9.

106

1 General Aspects of External Fixation

Contraindicated positions: 4, 5 and 6 Safe positions: 1, 2, 3, 7, 8, 9, 10, 11 and 12 Reference positions: 3, 4, 8 and 9 Comments Only console transosseous elements can be used in the projection of positions 10, 11 and 12. The use of positions 3, 4, 8 and 9 is optimal at this level because the transosseous elements will not restrict displacement of the soft tissue relative to the femur with motion of the knee joint.

Level VII

Transosseous elements recommended for use at femoral level VII: VII,3; VII,4; VII,8; VII,9 and VII,3-9.

1.9 Atlas for Insertion of Transosseous Element Reference Positions

107

Contraindicated positions: 5, 6 and 7 Safe positions: 1, 2, 3, 4, 8, 9, 10, 11 and 12 Reference positions: 3, 4, 8 and 9 Comments Only console transosseous elements can be used in the projection of positions 11, 12 and 1. The use of positions 3, 4, 8 and 9 is optimal at this level because the transosseous elements will not restrict displacement of the soft tissue relative to the femur with motion of the knee joint.

Level VIII

Transosseous elements recommended for use at the femoral level VIII: VIII,3; VIII,4; VIII,8; VIII,9 and VIII,3-9.

108

1 General Aspects of External Fixation

1.9.5 Tibia5 The figures show sections through the tibia at each of the principal levels I–VIII. Of 96 positions defined in accordance with MUDEF, 75% (72 positions) are designated as safe positions,and 49 (51%) are identified as tibial RPs for transosseous element insertion. On the tibia there are three Yin meridians with a centrifugal direction of energy motion: the liver meridian (F),the spleen meridian (Rp) and the kidney meridian (R).There are three Yang meridians with centripetal direction of energy motion: the stomach meridian (E), the bladder meridian (V), and the gallbladder meridian (VB). The meridians on the tibia are represented by 34 active points.

5

The material presented was prepared in collaboration with D.A. Mykalo.

1.9 Atlas for Insertion of Transosseous Element Reference Positions

109

Contraindicated positions: 6, 7 and 8 Safe positions: 1, 2, 3, 4, 5, 9, 10, 11 and 12 Reference positions: 2, 3, 9 and 10 Comments Only console transosseous elements can be used in the projection of positions 2, 10 and 12. The use of positions 2, 3, 9 and 10 is optimal at this level because the transosseous elements will not restrict displacement of the soft tissue relative to the tibia with motion of the knee joint.

Level I

Transosseous elements recommended for use at level I of the tibia: I,2; I,3; I,9; I,10 and I,3-9.

110

1 General Aspects of External Fixation

Contraindicated positions: 6, 7 and 8 Safe positions: 1, 2, 3, 4, 5, 9, 10, 11 and 12 Reference positions: 1, 2, 3, 4, 9 and 10 Comments Only console transosseous elements can be used in the projection of positions 1, 2 and 12. The use of positions 1, 2, 3, 4, 9 and 10 is optimal at this level because the transosseous elements will minimally restrict displacement of the soft tissue relative to the tibia with motion of the knee joint.

Level II

Transosseous elements recommended for use at level II of the tibia: II,1; II,2; II,3; II,4; II,9; II,10; II,3-9 and II,4-10.

1.9 Atlas for Insertion of Transosseous Element Reference Positions

111

Contraindicated positions: 6, 7 and 8 Safe positions: 1, 2, 3, 4, 5, 9, 10, 11 and 12 Reference positions: 1, 2, 3, 4, 9, 10 and 12 Comments Only console transosseous elements can be used in the projection of positions 1, 2 and 12. The use of positions 1, 2, 3, 4, 9, 10 and 12 is optimal at this level because the transosseous elements will not restrict displacement of the soft tissue relative to the tibia with motion of the knee joint.

Level III

Transosseous elements recommended for use at level III of the tibia: III,1; III,2; III,3; III,4; III,9; III,10; III,12; III,3-9 and III,4-10.

112

1 General Aspects of External Fixation

Contraindicated positions: 6, 7 and 8 Safe positions: 1, 2, 3, 4, 5, 9, 10, 11 and 12 Reference positions: 1, 2, 3, 4, 9, 10, 11 and 12 Comments Only console transosseous elements can be used in the projection of positions 1, 2 and 12. The use of positions 1, 2, 3, 4, 9, 10, 11 and 12 is optimal at this level because the transosseous elements will not restrict displacement of the soft tissue relative to the tibia with motion of the adjacent joints.

Level IV

Transosseous elements recommended for use at level IV of the tibia: IV,1; IV,2; IV,3; IV,4; IV,9; IV,10; IV,11; IV,12; IV,3-9 and IV,4-10.

1.9 Atlas for Insertion of Transosseous Element Reference Positions

113

Contraindicated positions: 5, 6 and 8 Safe positions: 1, 2, 3, 4, 7, 9, 10, 11 and 12 Reference positions: 1, 2, 3, 4, 9 and 12 Comments Only console transosseous elements can be used in the projection of positions 2, 11 and 12. The use of positions 1, 2, 3, 4, 9 and 12 is optimal at this level because the transosseous elements will not restrict displacement of the soft tissue relative to the tibia with motion of the adjacent joints.

Level V

Transosseous elements recommended for use at level V of the tibia: V,1; V,2; V,3; V,4; V,9; V,12; V,3-9 and V,4-10.

114

1 General Aspects of External Fixation

Contraindicated positions: 5, 6 and 9 Safe positions: 1, 2, 3, 4, 7, 8, 10, 11 and 12 Reference positions: 1, 2, 3, 4 and 12 Comments

Level VI

Only console transosseous elements can be used in the projection of positions 3, 11 and 12. Because of the close proximity of the tibialis anterior neurovascular bundle to the lateral tibial shaft in the projection of position 9, it is necessary to use console transosseous elements in the projection of position 3 that penetrate only the medial cortical plate. Insertion of K-wires in the frontal plane is possible through the anterior third of the tibia at this level. The use of positions 1, 2, 3, 4 and 12 is optimal at this level because the transosseous elements will not restrict displacement of the soft tissue relative to the tibia with motion of the ankle and (to a lesser degree) the knee joints.

Transosseous elements recommended for use at level VI of the tibia: VI,1; VI,2; VI,3; VI,4; VI,12 and VI,4-10.

1.9 Atlas for Insertion of Transosseous Element Reference Positions

115

Contraindicated positions: 5, 6 and 11 Safe positions: 1, 2, 3, 4, 7, 8, 9, 10 and 12 Reference positions: 1, 2, 3, 4, 8 and 9 Comments Only console transosseous elements can be used in the projection of position 12.The use of positions 1, 2, 3, 4, 8 and 9 is optimal at this level because transosseous elements will not restrict displacement of the soft tissue relative to the tibia with motion of the ankle joint.

Level VII

Transosseous elements recommended for use at level VII of the tibia: VII,1; VII,2; VII,3; VII,4; VII,8; VII,9; VII,3-9; VII,4-10 and VII,2-8(2-8).

116

1 General Aspects of External Fixation

Contraindicated positions: 5, 6 and 11 Safe positions: 1, 2, 3, 4, 7, 8, 9, 10 and 12 Reference positions: 1, 2, 3, 4, 8, 9 and 10 Comments Insertion of transosseous elements at this level is contraindicated at positions 5 and 11.The potential for injury to the anterior and posterior tibial neurovascular structures is significant with insertion at these positions. The use of positions 1, 2, 3, 4, 8, 9 and 10 is optimal at this level because the transosseous elements will not restrict displacement of the soft tissue relative to the tibia with motion of the ankle joint. Level VIII

Transosseous elements recommended for use at level VIII of the tibia: VIII,1; VIII,2; VIII,3; VIII,4; VIII,9; VIII,10; VIII,3-9, VIII,2-8(2-8) and VIII,4-10.

1.10 Preoperative Preparation

1.10

Preoperative Preparation

Preoperative preparation of patients for transosseous osteosynthesis includes clinical examination of the general condition and the local status. Laboratory tests include general analysis of blood and urine,determination of blood group, Rhesus factor status, blood sugar and serum albumin, coagulation tests, determination of markers of hepatitis B and C and HIV status, and the Wassermann test. Indications for a conservative approach to treatment include swelling pressure of the soft tissue of the injured extremity (increase in length of a circle at any level more than on 50–60 mm), change in colour of the skin, asymmetry in blood ﬂow of more than 40%, and disturbance in homeostasis to hypercoagulation. Drug therapy includes adequate dosages of spasmolytics, anticoagulants and thrombolytics. Exercise therapy and reﬂexotherapy are also advisable.Treatment with active monitoring and adjustment is continued for 3–7 days. The presence of a specified symptom complex is not a contraindication to the use of the so-called basic variant of external fixation in patients with fractures in which only basic transosseous elements are inserted.

a

117

Moderate distraction between basic supports is performed for rough elimination of displacement of bone fragments. Assembly of the device can be completed later. In order to make a full diagnosis in patients with polytrauma, and also in those with accompanying diseases, the advice of other specialists should be sought; these include, among others, therapists, surgeons, neurosurgeons, angiologists, urologists and endocrinologists. Cleaning and sterilization of cantres of chronic infection should be included in the preoperative preparation protocol in orthopaedic pathology. In patients with bone fractures plain radiography is carried out in two standard projections: the AP and lateral views. If it is not possible to image both joints on one film: the AP radiograph should be of the proximal joint, and the lateral radiograph of the distal joint. Sometimes radiographs in additional planes (frontal and sagittal) may be necessary. With deformations of the lower extremities, only radiographs from the hip to the ankle allow the mechanical axis to be defined. If it is not possible to obtain

b

Fig. 1.10.1a,b. Apparatus on the lower leg (a) with a cover and foot support and (b) with the foot supported by a rubber sling [86]

118

1 General Aspects of External Fixation

radiographs of the necessary length, the use of two or three separate films may be adequate. The principles for selection of an individual apparatus for osteosynthesis are considered below in section 1.11. Crutches of the necessary size should be made available beforehand for patients with pathology of the lower extremities. The preoperative preparation protocol includes provision of at least two cotton covers for the apparatus.The cotton cover should not close fingers (hand or foot). During winter an additional cover with external water-proofing and internal insulating layers is necessary. It is also necessary for patients to have available beforehand special clothes with the arm or leg, as appropriate, enlarged. A foot support is necessary for patients with external fixation of the tibia and fibula (Fig. 1.10.1). Current legislation requires that the patient be made aware not only of the plan of treatment, but also of the basic features of external fixation to an extent that will ensure compliance during the postoperative period. In the case of external fixation in a child, a similar conversation should take place with the parents. Informed consent is signed by both sides. It is necessary to warn the patient about the inconveniences of frame bearing and to draw the patient’s attention to the passage of transosseous elements through soft tissue and bone. The particular requirement for the observance of aseptic technique and the use of antiseptics during the postoperative period should be emphasized. The patient should know and understand the manipulations that need to be made during the postoperative period for the resolution of problems of osteosynthesis: compression, distraction, mutual displacement of the external support, and replacement and reinsertion of the transosseous elements, etc. The patient should receive general guidance concerning possible complications and the actions necessary for their prevention and treatment. The patient and the doctor should be aware that the risk of infectious complications is higher with transosseous osteosynthesis than with internal fixation. However, the damage to the health of the patient from infectious complications after external fixation,and the time and effort necessary for their treatment, are much less than for inﬂammatory complications occurring after internal fixation. Before surgery (providing it is not in the context of acute trauma) the patient takes an antiseptic bath. Directly before surgery the operative field is shaved, drenched with Lugol’s solution or alcohol solution and wrapped with sterile bandage.The patient is then transported to theatre. The preoperative preparation of patients with orthopaedic pathology that involves contracture or vi-

cious cicatrix, etc. is described separately elsewhere in the book.

1.11 Principles of Frame Construction The general algorithm for the assembly of an external device includes: 1. Identification of the objectives in using an external device. 2. Identification of the optimal levels for locating the external supports of the device. 3. Identification of the possible transosseous elements on the basis of safe positions and reference positions. 4. Identification of a transosseous elements best suited to the particular clinical situation. 5. Selection of the type and size of external support for every level of transosseous element placement. 6. Marking of the selected levels and positions on the segment for transosseous element placement. 7. Transosseous element insertion and external support installation. Stages 1–5 are performed during preoperative planning. Stages 6 and 7 directly refer to operative intervention. General issues in carrying out each identified stage of the method of external device assembly are considered below.

1.11.1

Identification of Objectives

Fixation in traumatology and orthopaedics is a means to reach a common aim: the recovery (improvement) in anatomy, function and physiology of an injured limb. The most typical objectives of using a fixation device are: • To change of the spatial layout of bone fragments. Changing the location of the fragments using the specific techniques of external fixation can be either “single-stage” (in the process of the surgery) and discrete or effected over a certain time during the postoperative period. The resolution of this problem presupposes that the device will be dismantled after the necessary orientation of bone fragments has been achieved. The AO/ASIF system is used in this procedure when the device is dismantled immediately after internal fixation of the bone fragments. • For bone fragment fixation. The external fixation device is used only as a fixing device; for example, after open repositioning of bone fragments, compression arthrodesis, etc.

1.11 Principles of Frame Construction

•

For provision (improvement) of limb function during the postoperative period. To ensure limb support and movement, the external fixation device must fix bone fragments with sufficient rigidity. Furthermore, the transosseous elements must be placed so as to reduce the risk of pin-induced joint stiffness. The conditions to meet these requirements are considered in section 1.6.

In clinical practice, the external fixation device may have to meet the requirements of a combination of any two of the identified problems or solve all of them in aggregate. Therefore, a particular clinical situation often demands a compromise solution that ensures the maximum efficiency of all components of the external device.

1.11.2 Identification of the Optimal Levels for Locating the External Supports This stage of implementation of the method of external device assembly must be based on knowledge of the biomechanics of bone fragment management and fixation rigidity. The requirements to ensure optimal conditions for both bone repositioning and fixation are satisfied by the Ilizarov device. Its assembly involves two external supports for each bone fragment (one support for a short fragment,as an exception).The distance between the supports in each module must be as great as possible. The transosseous elements must be placed abarticularly and be located at a distance of 2–4 cm from the bone fracture line. Exceptions are the osteosynthesis of intraarticular or juxtaarticular fractures.

1.11.3 Identification of the Possible Transosseous Elements on the Basis of Safe Positions and Reference Positions The atlas presented above is used. If one of the tasks of using external fixation is the provision (improvement) of the function of adjacent joints, only RPs are used. Among these those located contralaterally relative to the bone are particularly important; for example, 2 and 8, 3 and 9, 6 and 12, etc. It is possible to insert a wire in the projection of these positions. It is also possible to insert a half-pin on the side of any RP. For example, if the RPs at level V of the shoulder are 4 and 10, one can either use the wire V4-10 or a half-pin: V,4,90 or V,10,90 (the angle of half-pin insertion here is given arbitrarily). If there is no contralateral position at this level, it is expedient to use half-pins (cantilever wires).

119

1.11.4 Identification of Transosseous Elements Best Suited to the Particular Clinical Situation This item proceeds from the tasks of osteosynthesis. The use of wires is more effective for repositioning bone fragments in fractures, whereas the use of halfpins increases the rigidity of bone fragment fixation. At the same time it should be remembered that the use of half-pins is inappropriate in the presence of marked osteoporosis. In the opinion of some authors, one should avoid situations where transosseous elements pass through more than two or three acupuncture points on different meridians or cross one meridian two or three times [80, 85, 87]. However, it is not impossible that transosseous elements may be used as stimulators at biologically active points [83, 88].

1.11.5 Selection of the Type and Size of External Support for Every Level of Transosseous Element Placement A closed external support provides the greatest stability of bone fragment fixation and repositioning. However, rings often cannot be used, for example at levels 0, I and II of the upper arm and upper leg. It is inappropriate to use closed basic supports when they mechanically obstruct the movement of the adjacent joint. Sector (arched) and monolateral supports are the least bulky and are relatively simple to install. However, they provide less potential for repositioning and less rigidity of the osteosynthesis. The diameter of the external supports is selected taking account the circumference of the sector at every level of insertion of the transosseous elements. The choice of the standard size should take into account the probability of soft-tissue oedema increasing the circumference by 4–6 cm and the displacement of the soft tissue relative to the repositioning of the bone fragments. Due to anatomical and interindividual variations the circumference of the segment is different at every level. Hence, the diameter of supports at every level is different or the device is assembled from supports of the maximum standard size for the particular situation. In the former case the rigidity provided by the structure is reduced due to the need for connection plates in the completed device and its installation becomes more complicated; however, the dimensions of the device are reduced. It is easier to assemble the device from supports of the same standard size, which provides more freedom for manipulations; however, the device is bulkier. The rigidity of bone fragment fixation

120

1 General Aspects of External Fixation

Fig. 1.11.1. Main types of external support [22]

inevitably decreases due to the increase in the diameter of some supports. Figure 1.11.1 shows the most frequently used closed and open external supports.

Thus, in every particular situation one should look for a reasonable compromise based on the proposed priorities: provision of greater rigidity of the osteosynthesis, minimization of the dimensions of the exter-

1.11 Principles of Frame Construction

a

121

b

Fig. 1.11.2a,b. If, for example, the required position is 8 (a), it is a gross error to place the drill sleeve on the bone arbitrarily (at position 9, for example) and then change its angle in the transverse plane (b) in the belief correct placement will then be achieved

nal structure, the need for wider freedom for changing spatial orientation of the fragments, or provision of the maximum possible motion of the joints. For example, in arthrodesis of a knee, the possible locations for transosseous element insertion are extended by using safe positions. In contrast, for mobilization of a joint using external fixation techniques, the device should be assembled on the basis of transosseous elements inserted in the projection of RPs. To reduce the time of surgical intervention the external structure (the frame of the device) should be preassembled and produced for sterilization as a whole or in separate modules together with the necessary additional equipment.

1.11.6 Marking of the Selected Levels and Positions on the Segment for Transosseous Element Placement Any sterile marker can be used. In case of an acute injury this stage should be carried out after reconstruction of the limb axis and rough elimination of the displacement of the fragments by means of skeletal traction on the orthopaedic extension table.

1.11.7 Transosseous Element Insertion and External Support Installation The procedure for transosseous element insertion and the specific features of installation of the external supports depend on the segment being operated upon, the type of the pathology, and the tasks of osteosynthesis. The operation generally starts from basic transosseous element insertion. For insertion of wires one should use discontinuous boring at the maximum rotational speed of the drill of 850 revolutions per minute, cooling the wire with a

gauze tampon impregnated with alcohol, and regulating (up to 20 H) the axial pressure on the wire.After the guiding end of the wire passes the second cortical plate the drill should be disconnected and further insertion of the wire through the soft tissues is achieved using gentle hammer strikes on the base of the wire. When using a wire with an olive stop a puncture of 2–3 mm should be made in the skin. The guiding end of the wire should not be pulled in an attempt to insert the stop to the bone. In this case the punching technique is also used. To insert a spiral stop as far as the bone the wire is pulled at the guiding end with simultaneous rotation of the curvature in the soft tissue. Half-pins with a cortical and spongy thread should be inserted in the diaphyseal and metaphyseal parts of the bone, respectively. Insertion of a half-pin through the centre of the bone breadth is limited by needles inserted subperiosteally.The plane in which the needles are inserted must correspond to the plane in which the transosseous element is to be placed (Fig. 1.11.2). After the drill sleeve is placed at the specified angle to the bone (Fig. 1.11.3), the handle is removed from it. In metaphyseal bone, it is sufficient to make a canal using a 3-mm awl. For insertion of a pin in diaphyseal bone, a canal is formed with a diameter corresponding to the standard size of the pin and in relation to the bone tissue density. The canal diameter is 2.7 mm for a 4-mm half-pin,3.8 mm for a 5-mm half-pin,and 4.8 mm for a 6-mm half-pin. In osteoporosis the diameter of the canal must be 0.1–0.2 mm less. Insertion of the pin without a self-tapping guiding end must be preceded by thread formation in the bone with a tap. When transosseous elements pass through the ﬂexion surface of a segment the adjacent joint is placed in the extension position and vice versa (Fig. 1.6.2). It is not always possible to place the limb in the specified position during insertion of transosseous elements

122

1 General Aspects of External Fixation

a

b

Fig. 1.11.3a,b. A special drill sleeve is used to insert a half-pin at a specified angle to the longitudinal (anatomical) axis of the bone fragment (Fig. 1.4.4). a Sleeve placed at 90◦ : in the fixator the calibrated wire is fixed at the mark giving the location of the sleeve at the necessary angle. b Sleeve placed at 70◦ : when drilling is started the sleeve is inclined until the calibrated wire bears against the bone

while operating under conditions of skeletal traction on an orthopaedic extension table. In such cases, before insertion of the wire through the extension surface of a segment the skin is displaced (manually or with the help of a special hook) towards the adjacent joint. When using only RPs for transosseous element

Fig. 1.11.4. Mounting of the frame of the device starts from basic supports that must generally be located perpendicular to the respective bone fragment. In this case the device is to control the repositioning of the bone fragments (Fig. 1.4.10). One of the calibrated wires is removed and the two remaining wires are pulled out an equal distance and inserted as far as they will go into the diaphyseal part of the bone fragment. If the fragment is short, the length of one of the wires is altered according to the diagram in accordance with the bone relief. The support is placed parallel to the wires

insertion there is no need to perform these manipulations. After insertion of transosseous elements, presterilized gauze pad fixators are strung on them. These comprise plastic or rubber discs with diameters of 10– 15 mm for wires and 20–25 mm for half-pins.The gauze pad fixators placed on the side of the stopper of the wires must be distinguishable, for example by colour or shape. Mounting of the frame of the devices starts from basic supports (Fig. 1.11.4). The external supports are oriented relative to the bone in the horizontal plane (so-called “centring” of the external supports relative to the soft tissue) according to the individual features of every segment. This procedure is described in more detail in the respective sections of the book. Wires and especially half-pins should not be bent to fix them to the external supports of the device. If the external end of a transosseous element is located at a certain distance from the support, gasket washers or posts (brackets) should be used. An exception to this is when elastic deformation of transosseous elements is used intentionally in, for example, the repositioning of bone fragments or to increase the rigidity of the osteosynthesis. Wires are tensioned with the help of a wire tensioner, that is a dynamometric wire tensioner. Wire tensioning by turning the wire fixator during nut tightening has been developed at the Russian Ilizarov Research Center. Wire-fixation bolts with a hexagon head are used (Fig. 1.11.5). There are also alternative ways of wire tensioning (Fig. 1.11.6). The protruding ends of the wires are cut off at a distance of 30–40 mm from the outer edge of the support

1.11 Principles of Frame Construction

123

a

b Fig. 1.11.5a,b. The maximum possible tensile force of the wire depends on the moment acting on the bolt resulting from the wire tensile force tending to tighten the bolt (b c) or tending to untighten the bolt (b d). The maximum tensile force of the wire is higher if a wire tensioner is used (b a and b) [22, 23]

a

b

Fig. 1.11.6a,b. Wire tensioning by means of a traction clip (a) and by means of a male post (b)

a

b

Fig. 1.11.7a,b. If the half-pin is not inserted perpendicular to the anatomical axis of the bone fragment it is fixed to the support using two posts, a male and a female (a) or two male posts. If two female posts are used the half-pin cannot be removed without dismantling the support. The half-pin can also be fixed using an L-shaped clip (b)

124

1 General Aspects of External Fixation

a

b

Fig. 1.11.8a,b. To reduce the number of radiographs in fracture reduction a device to determine the quality of the repositioning is used (Fig. 1.4.10). Neighbouring calibrated wires are pulled out the same distance and fixed on a plate. At the minimum distance from the location of the fracture the wires are inserted until they bear against the bone fragment. The third wire is then inserted until it bears against the other fragment (a). If precise reduction has been achieved the marks of all the calibrated wires are at the same level (b)

and are bent over. One should avoid repeated bending of the free ends of the wires as subsequent straightening of the wires (to restore the tensile force for repositioning) may be necessary and the wire may fracture at the place of the curvature. There are special tips for half pins (Fig. 1.11.7) and for bone fragment reduction control (Fig. 1.11.8). The transosseous elements providing osteosynthesis rigidity (usually half-pins) must be fixed to the external supports only after repositioning of the bone fragments. An exception to this is when the half-pin is initially used as a reducing element. In case where the transosseous elements fixing the proximal and distal bone fragments are not located in parallel, they are connected by hinges. Their jaws must be coaxial with the respective bone fragments. Skewness and bending of the hinge jaws towards one another are inadmissible. In cases in which angular deformation is to be eliminated with time the subsystem includes three hinges: two axial and one swivel. Axial hinges are located strictly in parallel on the opposite sides of external supports. The location of the axis of rotation of a pair of axial hinges is determined from the tasks of osteosynthesis. The swivel hinge is placed on either the concave or the convex side of a deformation. It is possible to place two hinges on the concave side and two hinges on the convex side of a deformation. More detailed information about Ilizarov hinges is given in the sections devoted to deformations of long bones in part 2. After installation of the device is completed, movements in adjacent joints are performed with the maximum possible amplitude. If soft-tissue tension is present, the skin and, if necessary, the fascia are cut, displaced relative to the transosseous element and sutured. If it is necessary to make an incision of over

3 cm, it is recommended that the transosseous element be reinserted. The skin where a transosseous element emerges is covered with dressings of 4–6 cm2 impregnated with 70% ethyl alcohol. A comparative radiograph taken in the operating room is obligatory. By means of special positioning in the bed or by means of attachments to the ExFix the joints are placed in the position specific for every segment depending on the pathological condition leading to the surgical intervention. The external structure is covered with a cotton cover.

References 1. Beidik OV, Butovsky KG, Ostrovsky NV, Lyasnikov VN (2002) External transosseous osteosynthesis modeling. Tesar-Izdat, Saratov 2. Karlov AV, Khlusov IA (2000) Adjustable cellular and tissue actions of optimum biomechanics of external fixation devices. In: Proceedings of the scientific-practical conference: RSC “RTO”, vol 2, Kurgan, pp 185–186 3. Karlov AV (2003) Regulator mechanisms of optimal biomechanics in external fixation system (dissertation). RSC “RTO”, Kurgan 4. Agadzhanian VV, Pronskih AA, Ustyantseva IM et al (2003) Polytrauma. Nauka, Novosibirsk 5. Moroni A, Faldini C, Marchetti S et al (2001) Fixation in osteoporotic bone using hydroxyapatitecoated tapered external fixation pins – a prospective randomized study in wrist fractures (abstract). In: Proceedings of the Fifth Congress of the European Federation of National Associations of Orthopaedics and Traumatology, Greece, p 120

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6. Caja VL, Piza G, Navarro A (2003) Hydroxyapatite coating of external fixation pins to decrease axial deformity during tibial lengthening for short stature. J Bone Joint Surg Am 85-A:1527–1531 7. Golubev GSh (1997) Ilizarov’s external fixator computer control in clinical conditions. SKNC VSH, Rostov-on-Don 8. Pichkhadze IM (1994) Some of the theoretical grounds of osteosynthesis and its practical realization with computer aid. Vestnik travmatologii i ortopedii imeni Priorova (Priorov bulletin of traumatology and orthopedics-PBTO) 3:9–13 9. Slobodsky AB (2002) Optimization of treatment of long bones fractures of the lower extremities with the help of computer technologies(Abstracts). In: Proceedings of the Congress “People and his health”. Ed. Kornilov N.V., Saint Petersburg, p 102 10. Shevtsov VI, Nemkov VA, Sklyar LV (1995) Ilizarov apparatus. Biomechanics. Periodika, Kurgan 11. Shtarker H,Volpin G, Stolero J et al (2002) Computerized tomography malalignment test for planning and correction of combined planar and rotational lower limb deformities by the Ilizarov method. In: Proceedings of the SICOT/SIROT XXII World Congress, San Diego, USA, p 72 12. Cherkashin A, Hong Lin, Birch I, Samchukov M (2002) Preventing axial deviation complications during deformity correction using “LegPerfect” planning system. In: Proceedings of the SICOT/ SIROT XXII World Congress, San Diego, USA, p 244 13. Morandi M (2003) Taylor spatial frame. Minerva Ortop Traumatol 54:54–56 14. Al-Sayyad M (2004) The Taylozarov: an easy and precise technique to achieve residual deformity correction. In: Proceedings of the Third Meeting of the International Association for the Study and Application of the Method of Ilizarov, Istanbul, p 258 15. Atef H, Qaddoumi J, Whately C (2004) Acute tibial fractures treated with the Taylor spatial frame. In: Proceedings of the Third Meeting of the International Association for the Study and Application of the Method of Ilizarov, Istanbul, p 358 16. Binski J (2004) New devices. In: Proceedings of the Third Meeting of the International Association for the Study and Application of the Method of Ilizarov, Istanbul, p 61 17. Krause N, Mendicino R, Shimada K et al (2004) Computer-aided bone distraction. US Patent no. 6,701,174 B1 18. Glozman Z, Liram M, Eidelman M (2004) Computer assisted program for planning of the Taylor spatial frame. In: Proceedings of the Third Meeting of the International Association for the Study and Application of the Method of Ilizarov, Istanbul, p 260

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19. Kontes VD (1998) The method of remote reduction at tibial close fractures and device for its implementation. Patent no. 2165742, Russian Federation. Applied 26.03.1996, published 27.07.1998 20. Shevtsov VI, Popkov AV, Burlakov EV, Rutz FJ (1993) Operative lengthening of femur by Ilizarov with use of automatic distraction/The informationmethodical letter. RSC “RTO”, Kurgan, p 17 21. Shevtsov VI, Shchudlo MM, Utkin VA, Erofeev SA (1996) Mathematical modelling of distraction osteogenesis. Genij Ortopedii 1:6–13 22. Shevtsov VI, Popkov AV (1998) Operative lengthening of lower extremities. Meditsina, Moscow 23. Popkov AV, Shevtsov VI (2001) Achondroplasia. Meditsina, Moscow 24. Solomin LN, Kondratiev AS, Mitrenin VB et al (2004) The automated manipulator for reduction of bone fragments. GNTSR “TSNII RTK”, SaintPetersburg 25. Kaplunov OA (2002) Transosseous osteosynthesis according Ilizarov in traumatology and orthopedy. GEOTAR-MED, Moscow, 304 p. 26. Shved SI, Sysenko Yu M (1997) The methods of bone fragment control in the treatment of patients with close diaphyseal comminuted fractures of long bones. Geniy Ortopedii 1:41–44 27. Shevtsov VI, Shved SI, Sisenko JM (2002) Transosseous osteosynthesis in treatment of comminuted fractures. ZAO “Dammi”, Kurgan, 326 p. 28. Adamovich IS (1985) Mathematical modeling of the wire and evaluation of binding and metal plasticity for rigidity for compressive-distractive apparatus. In: Kalnberz VK (ed) Apparatus and methods of external fixation in traumatology and orthopaedics, vol 3. Riga, pp 7–11 29. Evseev VI, Korepanov MG (1988) Biomechanic modeling of osteosynthesis. In: Kalnberz VK (ed) Modern problems of biomechanics, vol 5. Zinatne, Riga, pp 73–93 30. Blokha AG (1992) Mathematical modeling of system “apparatus-extremity segment” at transosseous compression-distraction osteosynthesis. In: Biomechanics for protection of life and health of man. Nizhni Novgorod, pp 28–29 31. Begun PI, Afonin PN (2002) Computer modeling in biomechanics. The Manual. SPbGETU, St. Petersburg, 72 p. 32. Novitskaja NV, Stakheev IA (1975) Device for Ilizarov frame for definition of bone fragment mobility in external fixation. Ortopedija, Travmatologija i Protezirivanije 4:75–76 33. Karptsov VI (1975) Objective methods of monitoring during bone fractures treatment using external fixation (PhD thesis). LITO, Leningrad, 163 p.

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34. Morgun VV (1986) Acoustoemissive method of biomechanical modes validation in external fixation apparatus. In: Advances of biomechanics in medicine. Proceedings of an international symposium, vol 3. RITO, Riga, pp 578–583 35. Morgun VV (1989) Transosseous compressiondistraction osteosynthesis of bone fractures in conditions of a controllable biomechanical mode (Abstract of PhD thesis). KhNIITO, Kharkov, 22 p. 36. Shchurov VA, Gorbachev LJ (1998) Estimation of micromobility of bone fragments. In: Proceedings of the 4th Russian conference on biomechanics “Biomechanics-98”, Nizhni Novgorod, p 229 37. Kornilov NV, Samojlov KA, Karptsov VI (1989) The condition of reparative osteogenesis in patients with femur fractures using wire-pin external fixation. Vestnik Hirurgii imeni I.I. Grekova 1:66–68 38. Pustovojt MI, Kotskovich IM, Strutinsky JI (1993) Ilizarov distraction regenerate training with the help of controlled mechanical-dynamical inﬂuences. Ilizarov method: achievements and prospects. In: Proceedings of the international conference, devoted to the memory of the academician GA Ilizarov. RSC “RTO”, Kurgan, pp 225–226 39. Popsujshapka AK (1991) Functional treatment of shaft long bone fractures (clinical and an experimental research) (PhD thesis). KhNIITO, Kharkov, 323 p. 40. Ozhegov SI (1997) Explanatory dictionary of the Russian language. Azbukovnik, Moscow 41. Dulaev AK, Didikin AV (1999) Experimental development and substantiation of a method of “hybrid” osteosynthesis. In: Proceedings of the Conference “Modern technologies in traumatology and orthopedy”. CITO, Moscow, p 69 42. Rajasekaran S (1999) Hybrid fixation of complex tibial plateau fractures. In: Proceedings of the 21st Triennial World Congress of the Société Internationale de Chirurgie Orthopédique et de Traumatologie (SICOT), Sydney, p 605 43. Zeiler C (1999) Treatment of bone loss with an central wire distraction system controlled and regulated by tensile forces in vivo. In: Proceedings of the 21st Triennial World Congress of the Société Internationale de Chirurgie Orthopédique et de Traumatologie (SICOT), Sydney, p 151 44. Jacques E Jr (1999) Treatment of pseudarthrosis Ilizarov method. In: Proceedings of the 21st Triennial World Congress of the Société Internationale de Chirurgie Orthopédique et de Traumatologie (SICOT), Sydney, p 153

45. Pizzoli AL, Giotakis N, Lavini FM et al (2001) The use of Orthofix Hybrid external fixator in the treatment of proximal and distal meta-epiphyseal lesions of the tibia. Fifth Congress of EFORT, Greece, p 51 46. Demjanov VM, Dager NM, Abeleva GM (1986) Modern aspects of forearm closed shaft fractures treatment. Ortopedija, Travmatologija i Protezirivanije 12:57–61 47. Mamonov JP (1987) Combined osteosynthesis in shaft bone fractures. Vestnik khirurgii imeni I.I. Grekova1, pp 100–101 48. Sukhonosenko VM (1995) Surgical treatment of femoral bone mal-union complicated by extension knee joint contracture. In: Proceedings of the conference. “Actual problems of traumatology and orthopedy”. CITO, Moscow, pp 76–78 49. Tajlashev MM, Rahmatulin AG, Salatin PP, Puseva ME (1995) To a problem of operative treatment of shaft forearm fractures.Ortopedija i Travmatilogija Rossii 4:35–36 50. Gjulnazarova SV (2000) Modern methods of nonunion treatment. Ortopedija i Travmatilogija Rossii 1:78–83 51. Inan M, Karaoglu S, Türk CY,Argün M (1999) Overnailing Ilizarov method for treatment of nonunions after intramedullary nailing in femoral fractures. In: Proceedings of the 21st Triennial World Congress of the Société Internationale de Chirurgie Orthopédique et de Traumatologie (SICOT), Sydney, p 221 52. Murase T, Kishida Y, Hiroshima K (1999) Intrafocal pinning combined with external fixation for distal radial fractures: a preliminary report. In: Proceedings of the 21st Triennial World Congress of the Société Internationale de Chirurgie Orthopédique et de Traumatologie (SICOT), Sydney, p 188 53. Krupko IL (1974) Traumatology and orthopedy, vol 1. Meditsina, Leningrad, 424 p. 54. Ternovoj KS, Sinilo MI (1987) Mistakes and complications in traumatology and orthopedy. Mova, Kiev, 287 p. 55. Kljuchevskij VV, Suhanov GA, Zverev EV et al (1993) Osteosynthesis using rectangular-section nails.“ORTOPRO”, Yaroslavl, 322 p. 56. Viktorova NL (1995) Examination of treatment of long bone shaft fractures. Annali travmatologii i ortopedii 1:8–10 57. Kotenko VV, Korniliv NV, Kopisova VA et al (1996) Osteosynthesis using devices with thermomechanical memory. In: Kotenko VV (ed) Compression clips and circular clamps, part I. AO “Novokuznetskij Poligrafkombinat”, Novokuznetsk, 94 p. 58. Bogdanovich UJ (1981) Plate osteosynthesis. Meditsina, Leningrad, 146 p.

References

59. Vvedenskij SP (1983) Classification of compression-distraction devices and some technical development of new frames. In: Proceedings of the Conference “Invention and an efficiency work in traumatology and orthopedy”. CITO, Moscow, pp 50–54 60. Ilizarov GA (1976) Clinical and theoretical aspects compression and distraction osteosynthesis. In: Proceedings of the All-Union scientific-practical Conference “Theoretical and practical aspects of transosseous osteosynthesis”. RSC “RTO”, Kurgan, pp 7–11 61. Devjatov AA (1990) Transosseous osteosynthesis. Shtiintca, Kishinev, 316 p. 62. Kovalenko IL, Davydov AB, Belyh SI (1990) Combined osteosynthesis with application of biocompatible polymeric clamps in treatment of long bone fractures. Ortopedija, Travmatologija i Protezirivanije 7:11–15 63. Antoniadi JV, Runkov AV, Shlykov IL, Mukhachjov VA (1999) Combined osteosynthesis in pelvis injury. Actual questions of traumatology and orthopedy. GFUN “UNIITO”, Ekaterinburg, pp 8–12 64. Kotelnikov GP, Bezrukov AE, Volova LT, Nagoga AG (1995) Use of demineralised bone graft in treatment of hip fractures at elderly and senile patients.Annali traumatologii i ortopedii 1:48–52 65. Zulkarneev RA (1986) Combined osteosynthesis and its biomechanical substantiation. In: Kalnberz VK (ed) Medical biomechanics, vol 3. RITO, Riga, pp 469–474 66. Zulkarneev RA, Zulkarneev RR (2001) Combined osteosynthesis in osteoporotic fractures. In: Proceedings of the international Conference “Treatment of damages and diseases of pelvis bones”. UNIITO, Ekaterinburg-Revda, pp 115–116 67. Janson IA,Adamovich IS,Mastinja MO (1983) Basic factors inﬂuencing quantity of initial wire tension in devices of external fixation. Questions of biomechanics and rehabilitation. RITO, Riga, pp 109–118 68. Janson IA, Janson HA (1985) Some questions of biomechanics of external fixation: In: Kalnberz VK (ed) Devices and methods of external fixing in traumatology, vol 3. RITO, Riga, pp 78–80 69. Kalnberz VK, Janson IA (1986) Basic features of “wire”external fixation device biomechanics. In: Proceedings of the international Conference “Medical biomechanics”, vol 2. RITO, Riga, pp 475–480 70. Kalnberz VK, Adamovich IS, Perper MI, Janson IA (1988) Strained and deformed condition of a wire of external fixation device with rigid rings. In: Kalnberz VK (ed) Biomechanics: problems and researches. RITO, Riga, pp 198–203

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71. Huisres R, Chao EY (1985) Guidelines for external fracture fixation frame rigidity and strength. Devices and methods of external fixation in traumatology and orthopedy, vol 3. RITO, Riga, pp 63–65 72. Vasilenkajtis VV (1985) Biomechanical substantiation of compression-distraction osteosynthesis using “elastic-strained suspended path”. In: Janson IA (ed) Medical biomechanics, vol 3. RITO, Riga, pp 428–434 73. Kalnberz VK, Studers PJ, Dobelis MA (1988) Comparative research of Kirshner-wires, Steinmann rods and Shants-screws rigidity in identical experimental conditions and in clinic. Ortopedija, Travmatologija i Protezirivanije1 2:16–19 74. Tishkov NV (1995) Treatment of closed tibia shaft fractures using a method of transosseous osteosynthesis in region with small population density (Abstract of PhD thesis). IITO, Irkutsk, 20 p. 75. Solomin LN (1996) The controlled combined osteosynthesis of long bones: development, substantiation and clinical use (PhD thesis). IITO, Irkutsk, 348 p. 76. Evseeva SA, Solomin LN, Barabash AP (1996) Theoretical and experimental substantiation of support for a tension of axial compression wires rigidity in the combined strained fixation. The Bulletin of the Siberian branch of Russian Academy of Medical Science 4:18–20 77. Bejdik OV, Kireev SI (2000) Ways of a method of transosseous osteosynthesis according to GA Ilizarov optimization in treatment of orthopedic patients (Abstracts of a scientific conference), vol 1. RSC “RTO”, Kurgan, p 29 78. Shukejlo JA, Pechkurov AL, Kormilitsin OP (2000) Experimental research of gunshot fractures stability In: Proceedings of the Fifth All-Russia biomechanics Conference “Biomechanics-2000”.NNIITO, Nizhni Novgorod, p 140 79. Luvsan G (1990) Traditional and modern aspects of Eastern reﬂexotherapy, 2nd edn. Nauka, Moscow 80. Volkov MV, Oganesyan OV (1986) Restoration of the configuration and function of joints and bones (using author’s devices). Medicine, Moscow, 256 p. 81. Nechushkin AI, Oganesjan OV, Novikova EB (1976) About the reason of occurrence and the prevention of some complications in using of external fixation devices (the preliminary report). In: Actual questions of traumatology and orthopedy, vol 14. CITO, Moscow, pp 29–32 82. Shpilevsky IE,Tesakov DK,Lipov AL (1994) Prophylaxis of soft-tissue inﬂammation around of wires in external fixation devices. In: Modern aspects of traumatology and orthopedy. KNIITO, Kazan, pp 110–111

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83. Prokin BM, Dedeneva ZhG (1994) Some aspects of medical rehabilitation in Turner-Zudek syndrome. Travmatologia i ortopedia Rossii 1:92–97 84. Verkhozina TK, Solomin LN, Shevchenko VV (1998) Analysis of results of transosseous element insertion through biological-active points. In: Proceedings of the First International Pacific Congress on Traditional Medicine, VGMU, Vladivostok, pp 74–75 85. Ivannikov SV, Oganesjan OV, Shesternja NA (2003) External transosseous osteosynthesis in forearm fractures. BINOM, Moscow, 140 p. 86. Khrupkin VI, Artemiev AA, Popkov VV et al (2004) Ilizarov method in treatment of diaphyseal fractures of lower leg. GEOTAR-MED, Moscow 87. Oganesyan OV, Ivannikov SV, Korshunov AV (2003) The restoration of form and function of ankle joint by knuckle-and-distraction apparatus. BINOM, Meditsina, Moscow 88. Solomin LN, Yaichny OA, Zhirnov VA et al (2004) The inﬂuence of different methods of reﬂexotherapy on distraction regeneration in experimental study in rabbits. In: Present problems of traumatology and orthopedics. Velikij Novgorod, p 95

Suggested Reading Beidik OV, Sokulov IV (2000) Results of treatments of long bone diseases and injuries using external fixation devices with biocompatible implants.New tech, Kurgan Burny FL (1999) Mechanical monitoring of fracture healing using external fixation (abstract). In: Proceedings of the 21st Triennial World Congress of the Soci´et´e Internationale de Chirurgie Orthop´edique et de Traumatologie (SICOT), Sydney, p 300 Catagni MA (2002) Atlas for the insertion of transosseous wires and half-pins. Ilizarov Method. Medicalplastic, Milan

Ilizarov GA (1992) Transosseous osteosynthesis. Theoretical and clinical aspects of the regeneration and growth of tissue. Springer-Verlag, Berlin Heidelberg New York Kalnbernz VK (1983) Improvement of external fixation apparatus. In: Volkov MV (ed) Invention and rationalization activity in traumatology and orthopedics. CITO, Moscow, pp 91–92 Khrupkin VI, Artemiev AA, Popkov VV et al (2004) Ilizarov method in treatment of diaphyseal fractures of lower leg. GEOTAR-MED, Moscow Prokin BM, Dedeneva ZhG (1994) Some aspects of medical rehabilitation in Turner-Zudek syndrome. Travmatologia i ortopedia Rossii 1:92–97 Shved SI, Sysenko Yu M (1997) The methods of bone fragment control in the treatment of patients with close diaphyseal comminuted fractures of long bones. Geniy Ortopedii 1:41–44 Solomin LN (2004) Transosseous osteosynthesis. In: Kornilov NV,Gryaznukhin EG (eds) The traumatology and orthopedics (clinician’s guide), vol 1, chapter 5. Hippocrat, Saint-Petersburg, pp 336–388 Solomin LN, Kondratiev AS, Mitrenin VB et al (2004) The automated manipulator for reduction of bone fragments. GNTSR “TSNII RTK”, Saint-Petersburg Solomin LN, Kornilov NV,Voitovich AV et al (2004) The uniform designation method of transosseous osteosynthesis (method guidance no. 2002/134). RR. Vreden RRITO, Saint-Petersburg Solomin LN, Yaichny OA, Zhirnov VA et al (2004) The inﬂuence of different methods of reﬂexotherapy on distraction regeneration in experimental study in rabbits. In: Tikhilov RM (ed) Present problems of traumatology and orthopedics. Velikij Novgorod, p 95 Vvedensky SP (1978) Device for elimination of femur angular deformation. Travmatologia, ortopedia 8:71–72 Vvedensky SP (1978) The device for reposition of femur fragments (certificate of authorship no. 611612, USSR. Applied 25.06.1975, published 25.06.1978

2 Specific Aspects of External Fixation

2.1

Introduction

Part 2 must be considered only in the context of the information provided in part 1. The methods of external fixation by means of wire devices described below are based on the principles developed by Academician G.A. Ilizarov and the school of external fixation created by him. At the same time the manual presents alternative methods of combined external fixation (CEF) developed on the basis of the principles given in section 1.7. In identifying the indications for the use of external fixation the international classification of fractures and soft-tissue injuries developed by AO/ASIF is used. Identification of the position of the joint, and the amplitude of its movements is described in the text on the basis of the neutral zero position method accepted as the international standard [1]. The general stages in the process of external fixation of long-bone fractures are: 1. Identification of injuries and the basis for their correction. 2. Preoperative preparation. 3. Rough elimination of displacement of bone fragments on the fracture orthopaedic table. 4. Insertion of basic transosseous elements. 5. Assembly of external supports – the “frame” of the device. 6. Insertion of the reductionally fixing transosseous elements and their dynamic fixation to the external supports. 7. Achievement of the specified spatial orientation of bone fragments and splinters in a single-step (less frequently over a period of time) and rigid fixation of reductional transosseous elements to the external supports. 8. Insertion and rigid fixation of transosseous elements to the external supports in the order of bone fragment stabilization. 9. Variation of the technique depending on the segment, the level of bone destruction, and the tasks involved in restorative surgery. 10. Implementation of the tasks of the postoperative period.

Special sections in this part are devoted to specific features of external fixation of fractures and in orthopaedic pathology.

2.2

Fractures of the Humerus

In external fixation of the humerus (Figs. 2.2.1–2.2.17) according to the Ilizarov method wires of diameter 1.5 mm are used. The basic wires used in CEF are 1.8– 2 mm in diameter, and the wires used for reduction are 1.5 mm in diameter. Half-pins of diameter 5 mm are inserted into the diaphyseal part of the humerus and 4-mm half-pins or console wires are inserted into the epicondyle. For patients with bone diameters of 28– 30 mm it is permissible to use 6-mm threaded half-pins throughout the first three levels (0, I, II). The set for fixation must also include 2-mm console wires with a stop at the positions allowing various lengths of the wire to be inserted into the bone (5, 10, 15 or 20 mm). The supports for the first three levels of the upper arm (levels 0, I and II) are assembled on the basis of a half-ring that is “elongated”, if required, on each side by connection plates. The modern basic Ilizarov device set includes special half-rings with the ends bent up and elongated. At level III of the upper arm, two-thirds or three-quarter ring supports are used to allow movement of the limb. As a rule, in external fixation of the upper arm the reductionally fixing and distal basic supports have one standard size and the proximal basic support, if located at the first three levels (levels 0, I and II), is one or two standard sizes larger. Therefore, to connect the proximal basic support to the others, connection plates are used. The supports used at the three distal levels of the upper arm (levels VII, VIII and IX) are two-thirds or three-quarter rings to allow bending of the elbow. In fixation of juxtaarticular and intraarticular fractures (11- and 13-), radiotransparent external supports should preferably be used. To prevent formation of adduction contracture of the shoulder joint, the transosseous elements throughout the first four levels of the upper arm (0, I, II, III) are

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Fig. 2.2.1. The proximal basic support on the upper arm is oriented relative to the soft tissue so that the distance between the inner edge of the ring and the skin at the front and outside are within in the range 25–35 cm. The distance from the skin to the ring along the posterior aspect must be 10–15 cm more

placed in the position with the shoulder in abduction at an angle of not less than 70◦ . To prevent pin-induced joint stiffness of the elbow joint following insertion of the transosseous elements through the front semicircle of the upper arm and through the four distal levels of the upper arm (VI,VII,VIII,IX),the forearm is placed in the position of maximum extension. During insertion of the transosseous elements through the back semicircle of the upper arm the forearm is placed bent at 90◦ –120◦ . If it is impossible to change the position in the joints at these angles, the skin is shifted manually or with a thin hook in the direction of its natural displacement relative to the bone during movement in the adjacent joint. In using only reference positions for insertion of transosseous elements, it is not necessary to change the position of the joints. However, the skin must be displaced prior to insertion of transosseous elements in elongation of the segment, correction of deformities, bilocal fixation and other situations when it is necessary to create a “store” of soft tissue. Prior to fixation of the wires the external support must be properly oriented relative to the anatomical axis of the bone fragment and soft tissue (Figs. 2.2.1 and 2.2.2). The external supports must be located perpendicular to the anatomical (middle diaphyseal) axis

Fig. 2.2.2. The distal basic support of the upper arm is generally oriented when it is connected to the distal reductionally fixing support. Remember that the thickness of the soft tissue on the posterior aspect of the upper arm in the top third of the segment is much greater than in the epicondylar area. Therefore, during mounting of the device, the humerus appears to be displaced forward relative to the centre of the distal basic support

of the bone fragment to which they are fixed.An exception is when the supports are placed preliminarily in a position of hypercorrection; this is considered below. The intermediate reductionally fixing supports on the upper arm are oriented relative to the soft tissue depending on the method to be used to reduce the bone fragments. If the modules fixing the bone fragments are to be mutually displaced, the distance between the inner edge of the ring and lateral aspect of the upper arm (from the inside and outside) must be equal, and at the back it must be 10–15 cm more than at the front. If the position of the bone fragments is to be changed by means of transosseous elements inserted near the bone wound, the ring should be displaced during mounting by the necessary amount in the direction the bone fragment needs to move. It is possible to estimate the residual displacement from comparison radiographs. The ends of the wires and half-pins that are at a distance from the support after it is given the necessary spatial orientation are fixed using posts and/or gasket washers. The half-pins, unless they are basic or reductionally fixing transosseous elements, are stabilized by external supports only after the necessary spatial orientation of the bone fragments has been achieved. If the half-pin is inserted into the bone not parallel to the external support it is fixed to it by two posts, one with a threaded hole (female) and the other with a threaded end (male). It is possible to fix the half-pin to the sup-

2.2 Fractures of the Humerus

port or post with L-shaped clips in a manner analogous to fixation of wires by wire-fixation bolts with a lateral slot. The following sections describing particular methods of fixation contain phrases similar to: “When the device module is properly installed its connection rods are located parallel to the anatomical axis of the bone fragment.” However, it must be born in mind that when the basic support is fixed only with wire(s), its position is likely to change due to bending of the wires from the weight of the basic ring and the reductionally fixing ring connected to it. In such cases to control orientation of the module, it should be supported and the bending of the wires eliminated by hand. It is important to note that in all the fixation diagrams provided, the direction of insertion of reduction transosseous elements (wires, half-pins), and the locations of the stops on the wires are given conventionally as examples. In practice, one should be guided by the actual residual displacement of the bone fragments. To avoid damage to great vessels and nerves, the safe positions identified in the atlas of the levels recommended for insertion of reductionally fixing transosseous elements should be used. The size of the external supports in the diagrams provided is also shown conventionally. For reduction using wires the desired displacement of the bone fragments is achieved with the help of stops,at the expense of the accurate bending of the wire (Fig. 1.6.9). For reduction using half-pins, displacement is achieved by “pulling” or “pushing”, and for posts with a stop only by “pushing”(Fig. 1.6.10). It is also possible to use any technique for reduction that involves mutual displacement of external supports (Fig. 1.6.4– 1.6.8). Large splinters are reduced and fixed by means of wires with stops or with the help of console wires with stops (Fig. 1.6.13). If there are great vessels and nerves in the plane of a splinter, it is reduced and fixed using a fork-shaped rod (Figs. 1.4.8 and 1.6.14). Regional anaesthesia is generally used for external fixation of the humerus. Transport immobilization is removed on the surgical table after induction of anaesthesia. A pillow 12–15 cm high is placed under the patient’s head and between the scapulas, and the patient is laid so that the shoulder joint projects beyond the edge of the surgical table. In cases of skeletal traction, a wire is inserted through the olecranon (olecr., 3-9). It is strained and fixed to the reductionally fixing post (Fig. 2.2.3). The recommended position of the shoulder during skeletal traction in fractures of the proximal part of the humerus is abduction 90◦ , front deviation 20–30◦ , and external rotation 20◦ . In dislocation fractures (injury 11-B3), abduction of the shoulder should not exceed 50◦ . In fractures of the diaphysis (injuries 12-) and the

131

distal humerus (injuries 13-), the shoulder is placed at an angle of 90◦ with a frontal deviation of 15–20◦. Axial traction and manual manipulation improve the location of the bone fragments. To facilitate reduction, measures are taken to achieve“hyperextension” of the damaged segment to 5 mm controlling distraction at the post by comparison with the contralateral shoulder. X-ray contrast markers are placed on the skin (injection needles, fragments of wires) and radiographs in two standard planes are acquired for comparison, or ﬂuoroscopy is used. Lines are drawn on the skin of the front and outer aspects of the segment corresponding to the plane of the anatomical axis of each bone fragment. Using the special device shown in Fig. 1.8.2, the levels for insertion of the transosseous elements are marked. As clinical experience increases, comparison radiographs during skeletal traction are obtained only in cases of juxtaarticular and intraarticular fractures (11- and 13-). The operative field is treated and covered with drapes. Radiographic confirmation of an accurate reduction on the surgical table is a rule of external fixation of closed fractures. The practice of hastily assembling an external fixation device in the operating room and performing the reduction after the patient has been transferred to the outpatient department with daily stepwise radiographic monitoring of the manipulations is an unsatisfactory and discredited method of external fixation. An exception to this rule is when a fixation device is applied as described below.

2.2.1

Proximal Humerus (11-)

Ilizarov external fixation of fractures of the proximal humerus (11-) starts with insertion of two wires through the supracondylar area,one in the frontal plane and the other at an angle of 30◦ to it: VII,9-3 and VII,10-4. The markers on the radiograph acquired under conditions of skeletal traction facilitate insertion of the wire perpendicular to the anatomical axis of the distal bone fragment. An intermediate reductionally fixing ring support is installed at level IV of the upper arm, oriented relative to the bone and soft tissue and connected by three threaded rods with a three-quarter ring as the distal basic support.The connection rods must be parallel to the axis of the distal bone fragment. In this position wires VII,9-3 and VII,10-4 are fixed in the distal support after tensioning. In fractures 11-A2, 11-A3, 11-B1, 11-B2, as well as in slipped epiphysis and osteoepiphysis, the method of Ilizarov and Shved [2] is used to eliminate rotational displacement. To achieve this a wire with a stop is inserted through the proximal metaphysis in a plane close to the sagittal plane, i.e. I,5-11. The wire is fixed in the

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2 Specific Aspects of External Fixation

a

Fig. 2.2.3a,b. External fixation of the humerus involves preliminary elimination of the rough displacement of the bone fragments by skeletal traction. The equipment generally available on an orthopaedic traction table can be used. If a reductionally fixing post is unavailable it must be specially produced. a Device developed at the Russian Ilizarov Research Center [4]. b Structure based on minimum modification of an orthopaedic traction table b

half-ring of a larger standard size than the proximal basic support. With the help of this support, the proximal fragment is placed in the position of maximum external rotation. The bone fragment is then rotated inside through an angle of 45–50◦ . The second wire is inserted in the sagittal plane, i.e. I,12-6. As soon as the wire is inserted in the soft tissues of the posterior semicircle of the upper arm, the proximal fragment is placed in the position of maximum external rotation. After insertion of wire I,12-6, the proximal bone fragment is placed again in the position of internal rotation at 45– 50◦ . The wires I,5-11 and I,12-6 are fixed to the basic half-ring so that the axis is properly oriented relative to the soft tissue and is located strictly perpendicular to the axis of the proximal fragment. The larger half-ring is removed. When the fracture line spreads to level I, the epimetaphyseal area of the bone can also be used for insertion of wires (level 0). The distal fragment is placed in the mediophysiological position when the first finger is inserted in

the line of the deltoid-thoracic sulcus. All three supports are connected. Distraction is applied to create an interfragmentary diastasis of 4–5 mm if this was impossible by skeletal traction. Radiographs are obtained in two standard planes or an image intensifier is used. A wire is inserted for final reduction of the distal fragment at the level of the intermediate ring. The direction of its insertion and location of the stop depend on displacement of the proximal end of the distal fragment. To avoid injury to the great vessels and nerves, only safe positions as specified in the atlas for level IV of the upper arm are used. As an example, Fig. 2.2.4 shows wire IV,4-10. Figure 2.2.5 shows the scheme for combined external fixation (CEF) of fracture 11-A3.3. It is best to use only half-pins as proximal basic wires: I,8,120; I,11,130. Insertion of half-pins at an angle of 120–130◦ ensures that their free portion does not prevent abduction of the shoulder by resting against the acromial process of the scapula [3].

2.2 Fractures of the Humerus

a

133

b 2

3

5

4

6

1

I,6-12; I,9,120; II,8,80 —— IV,2-8; V,10,70 —— VII,3-9 (a) 1/2 160 140 3/4 140 3

4

5

1

2

I,5-11; I,12-6 —— IV,4-10 —— VII,9-3; VII,10-4 1/2 160

140

3/4 140

Fig. 2.2.4. Ilizarov external fixation device for fixation of fracture 11-A3.2

In intraarticular fractures (11-C), the wires are inserted through the acromion process of the scapula: acr.,7-1 and acr.,11-5. After tensioning they are fixed to the half-ring. The device is assembled from three supports, with the intermediate ring located at level IV. After distraction comparison radiographs in two planes are obtained. Large splinters are reduced and fixed using Kirschner wires with stops or console wires with stops.In their turn, these wires are fixed to the proximal support of the device using posts. Distal bone fragments are reduced in a manner similar to that described for fractures 11-A2, 11-A3, 11-B1 and 11-B2. The scheme for Ilizarov fixation of fracture 11-C1 is given in Fig. 2.2.6. In dislocation fractures (11-B3), the wires are inserted through the acromial process of the scapula: acr.,7-1 and acr.,11-5. After tensioning they are fixed to the half-ring. When manual techniques fail to reset the head of the humerus,a wire with a bayonet-shaped stop is inserted after moderate distraction, on the side of the axillary crease by-passing great vessels and nerves. By means of gradual traction of the wire, the head of the humerus is reset [4]. Dislocation of the head of the humerus can be reset in another way. A wire is inserted through the head

I,6-12; I,9,120; II,8,80 —— IV,2-8; V,10,70 1/2 160

140

(b)

Fig. 2.2.5a,b. CEF device for fixation of fracture 11-A3.3 (a). Support VII,3-9 is dismantled 2.5–3 weeks after surgery (b). Thus, the device assembly in the later stages of fixation includes only two external supports. The use of half-pin IV,8,90 instead of wire IV,2-8 allows dismantling of the internal half ring of the distal support

of the humerus in the sagittal plane: I,6-12 (in posterior dislocations) or I,12-6 (in anterior dislocations). This wire is strained in the half-ring and the head of the humerus is reset by traction behind it. In another variant, the wire is arched outward and fixed to the support using distraction clips. During tensioning the wire straightens bringing the head of the humerus out of the dislocation condition. Displacement of the head is accompanied by tension of soft tissues at the back. Therefore, after the manipulation is completed, the soft tissues must be cut as much as necessary or (more often) the wire I,6-12 must be substituted for another transosseous element, for example, the half-pin I,9,120. After reduction and fixation of the head of the humerus, external fixation is performed with a technique similar to that described for injuries 11-A2, 11A3, 11-B1, 11-B2. When full-volume external fixation is impossible, for example in the event of mass admission of casualties, in a severely injured patient, it is possible to carry out the so-called “fixed” variant of external fixation. A wire with a stop is inserted at levels I and VII. The

134

2 Specific Aspects of External Fixation

1

2

5

6

3

4

I,6-12; I,11-5; II,11-5 —— IV,4-10 —— VII,9-3; VII,10-4 1/2 160

3

4

5

6

7

1

2

acr.,7-1; acr.,11-5; 0,6-12; I,9,80 —— IV,4-10 —— VII,9-3; VII,10-4 1/2 160

140

3/4 140

140

3/4 140

Fig. 2.2.7. Ilizarov external fixation device for fixation of fracture 12-A2.1

Fig. 2.2.6. Ilizarov external fixation device for fixation of fracture 11-C1

proximal wire is strained and fixed to the half-ring and the distal wire is fixed to a three-quarter ring support. A moderate distraction force is applied between the supports: I,6-12 ↔ VII,3-9. In cases of an intraarticular fracture (11-C),the device applied is: acr.,7-1 ↔ VII,3-9. The “fixed” fixation variant is used as a least-evil solution and in cases when closed reduction of complicated intraarticular fractures (11-C3) is unattainable and open reduction is contraindicated the following device is applied: acr.,7-1; acr.,11-5 ↔ IV,4-10 — VII,9-3; VII,10-4 After the final comparison radiograph, the arm is placed in abduction at an angle of 45–60◦ by means of a wedge-shaped pillow. Exceptions are cases when the wires were inserted through the acromial process of the scapula.

2.2.2

Diaphyseal Fractures (12-)

2.2.2.1 Proximal Third Ilizarov external fixation of fractures of the proximal third of the humeral diaphysis (injuries 12-A1.1, 12A2.1, 12-A3.1, 12-B1.1, 12-B2.1, 12-B3.1) starts with insertion of the crossing proximal basic wires through the proximal metaphysis of the humerus. One is inserted

in the sagittal plane and the other at an angle of 30◦ to the first: VII,9-3 and VII,10-4. The proximal support based on an extended half-ring is oriented relative to the bone and soft tissue and the wires are fixed to it after tensioning. The intermediate ring support is then installed at level IV of the upper arm and is connected by three rods with the three-quarter ring distal support. The intermediate support is oriented relative to the bone and soft tissue. The connection rods must be parallel to the longitudinal axis of the distal bone fragment.After tensioning, the wires VII,9-3 and VII,10-4 are fixed to the distal support which,if properly installed,is perpendicular to the anatomical axis of the distal bone fragment. The proximal basic support is connected by three rods to the reductionally fixing support. Distraction is applied to create an interfragmentary diastasis of 5– 7 mm if this was not done by skeletal traction. Radiographs are obtained in two standard planes or an image intensifier is used. To eliminate residual displacement of the proximal bone fragment at level II, a reductionally fixing wire is inserted. To eliminate residual displacement at level IV, a second reductionally fixing wire is inserted. The direction of insertion of these wires, as well as the location of the stop on both of them, depend on the residual displacement of the bone fragments. To avoid injury to the great vessels and nerves only safe positions as specified in the atlas for levels II and IV of the upper arm are

2.2 Fractures of the Humerus

a

b 1

2

4

5

135

c 3

I,11,120; II,8,90 —— IV,4-10; VI,8,70 —— VII,3-9 (a) 1/2 160 140 2/3 140 I,11,120; II,8,90 —— IV,4-10; VI,8,70

(b)

I,11,120; II,8,90 —— IV,11,120; VI,8,70

(c)

1/2 160

1/3 160

140

1/3 140

tal basic support are two-thirds or three-quarter rings connected to form a single module. The reductionally fixing rings are oriented relative to the soft tissue, and the module is installed so that the connection rods are parallel to the anatomical axis of the distal fragment. Only then are the distal basic wires strained and fixed to the support. To preserve the orientation of the reductionally fixing supports relative to the soft tissue, the module comprising three distal supports is connected by three rods to the proximal basic support using, if required, connection plates (various diameters of the supports). Distraction is then applied between the reductionally fixing supports to create an interfragmentary diastasis of 4–5 mm if this was not done by skeletal traction. Radiographs are obtained in two standard planes or an image intensifier is used. To eliminate residual displacement of the proximal bone fragment, a reduction wire is inserted at level IV (or level III, depending on the line of the fracture). To eliminate residual displacement of the distal fragment, a second reduction wire is inserted at level V (or level VI). Figure 2.2.9 shows, as an example, wires IV,10-4 and V,4-10.

Fig. 2.2.8a–c. CEF device for fixation of fractures of the proximal third of the humerus (a). Support VII,3-9 can be dismantled 3–4 weeks after surgery (b). Thus, during the later stages of fixation the device includes only two supports. Use of half-pin IV,8,90 instead of wire IV,4-10 allows dismantling of the internal half-ring of the distal support (c)

2.2.2.2 Middle Third Ilizarov external fixation of fractures of the middle third of the humeral diaphysis (injuries 12-A1.2, 12A2.2, 12-A3.2, 12-B1.2, 12-B2.2, 12-B3.2) starts with insertion of the crossing wires II,6-12 and II,11-5. If the fracture is located closer to the proximal third of the diaphysis, proximal basic wires are placed at level I: I,6-12 and I,11-5. The distal basic wires VII,9-3 and VII,10-4 are then inserted. If the fracture is located at the border of the middle and distal thirds of the diaphysis, distal basic wires are placed at levelVIII:VIII,3-9 andVIII,2-8. After the proximal pair of the wires are strained, they are fixed in the extended half-ring that is preliminarily oriented relative to the bone and soft tissue as specified in section 2.2. At level III (or level IV, depending on the fracture site), a reductionally fixing support is placed. A second reductionally fixing support is placed at level V (or level VI). The reductionally fixing rings and the distal basic support are two-thirds or three-quarter rings connected to form a single module. The reductionally fixing rings are oriented relative to the soft tissue, and the module is installed so that the connection rods are

136

2 Specific Aspects of External Fixation

1

2

5

6

140

140

3

4

II,6-12; II,11-5 —— IV,10-4 →← V,4-10 —— VII,9-3; VII,10-4 1/2 160

3/4 140

Fig. 2.2.9. Ilizarov external fixation device for fixation of fracture 12-A3.2

parallel to the anatomical axis of the distal fragment. Only then are the distal basic wires strained and fixed to the support. To preserve the orientation of the reductionally fixing supports relative to the soft tissue, the module comprising three distal supports is connected by three rods to the proximal basic support using, if required, connection plates (various diameters of the supports). Distraction is then applied between the reductionally fixing supports to create an interfragmentary diastasis of 4–5 mm if this was not done by skeletal traction. Radiographs are obtained in two standard planes or an image intensifier is used. To eliminate residual displacement of the proximal bone fragment, a reduction wire is inserted at level IV (or level III, depending on the line of the fracture). To eliminate residual displacement of the distal fragment, a second reduction wire is inserted at level V (or level VI). Figure 2.2.9 shows, as an example, wires IV,10-4 and V,4-10. 2.2.2.3 Distal Third Ilizarov external fixation of fractures of the distal third of the humeral diaphysis (injuries 12-A1.3, 12-A2.3, 12-A3.3,12-B1.3, 12-B2.3, 12-B3.3)starts with insertion

of the intercrossing proximal basic wires III,6-12 and III,1-7. The distal basic wires VIII,9-3 and VIII,8-2 are then inserted.The proximal support is a two-thirds ring placed at level III of the upper arm and oriented relative to the bone and soft tissues as described in section 2.2. After tensioning, the wires III,6-12 and III,1-7 are fixed to the proximal basic support. At level V an intermediate reductionally fixing ring is installed and oriented relative to the soft tissue. The intermediate ring is connected by three rods to the proximal basic support. To achieve proper orientation of the supports, the connection rods must be parallel to the anatomical axis of the proximal bone fragment. The distal basic support is a three-quarter ring oriented perpendicular to the anatomical axis of the distal bone fragment and is connected by three rods to the intermediate support. In this position the wires VIII,9-3 and VIII,8-2 are fixed to the distal supports after tensioning. Distraction is applied to create a diastasis between the fragments of 4–5 mm if this was not done by skeletal traction. Radiographs are obtained in two standard planes or an image intensifier is used. To eliminate residual displacement of the proximal bone fragment,a reduction wire is inserted at level V.To eliminate residual displacement of the distal fragment at level VII, a second reduction wire is also inserted. Figure 2.2.11 shows, as an example, wires V,4-10 and VII,9-3. 2.2.2.4 Radial Nerve Injury Quite a frequent complication of diaphyseal fractures of the humerus is injury to the radial nerve.When clinical and laboratory examinations confirm functional nerve injury and immediate recovery is not possible, the method of Shved et al. [5] is used. After precise reduction and stable external fixation of the humeral fragments, a diastasis of 5–8 mm is created between the bone fragments. Creation of the diastasis results in moderate tension on the radial nerve, which prevents it becoming trapped and compressed between bone fragments. After formation of the primary bone commissure, stepwise coaptation of the bone fragments is carried out (0.25 mm four times a day). A complete course of simultaneous treatment is prescribed to recover the function of the nerve. When full-volume external fixation of diaphyseal fractures of the upper arm is impossible, for example in the event of mass admission of casualties, the so-called “fixation” variant of external fixation can be performed. Wires I,5-11 and VII,3-9 are inserted in the case of fracture of the proximal third of humeral diaphysis. The proximal wire is strained and fixed to the half-ring while the distal wire is fixed to a three-quarter

2.2 Fractures of the Humerus

a

b 1

5

3

4

6

2

II,5-11 —— II,8,120; IV,4-10 →← V,10-4; VI,7,70 —— VII,3-9 (a) 1/2 150 140 140 3/4 140 II,8,120; IV,4-10 →← V,10-4; VI,7,70

(b)

II,11,110; IV,8,90 —— V,10,90; VII,8,120

(c)

140

1/3 140

140

1/3 140

1

2

c Fig. 2.2.10a–c. CEF device for fixation of fractures of the middle third of the humerus 12-A3.2 (a). with positive bone wound healing dynamics, the basic supports can be dismantled 4 to 5 weeks after surgery (b). Thus, the use of modular transformation allows a device based on two supports to be used during the period of fixation. If half-pins IV,8,90 and V,10,90 are used in the initial assembly (a) instead of wires IV,4-10 and V,10-4, by the end of the fixation period the device will consist of two sectors (c)

5

7

6

3

4

III,6-12; III,1-7 —— V,4-10; VI,8,75 —— VII,9-3; VIII,9-3; VIII,8-2 2/3 150

137

140

Fig. 2.2.11. Ilizarov external fixation device for fixation of fracture 12-B2.3

3/4 140

138

2 Specific Aspects of External Fixation

a

b 1

5

3

4

c 2

6

7

II,5-11 —— III,8,120; V,4-10 —— VII,9-3; VIII,3-9; VIII,4,120; VIII,8,120 (a) 2/3 150 140 3/4 140 III,8,120; V,4-10 —— VII,9-3; VIII,4,120; VIII,8,120

(b)

IV,11,70; VI,8,120 —— VII,9-3; VIII,4,120; VIII,8,120

(c)

140

1/3 140

3/4 140

2/3 140

Fig. 2.2.12. CEF device for fixation of fractures of the distal third of the humerus (a). Transosseous elements VIII,4,120 and VIII,8,120 are 4-mm half-pins. The use of wire VII,3-9 (or VII,9-3) as a reduction wire is possible for displacement of the distal fragment within the limits of one-third of the bone diameter. If the displacement of the distal bone fragment exceeds this value, reduction of the fragment is achieved by displacement of the distal support relative to the module fixing the proximal bone fragment. Support II,5-11 can be dismantled 2 to 3 weeks after surgery (b). Thus, the assembly in later stages includes only two supports. If in the present arrangement the middle support includes the two half-pins: IV,11,70; VI,8,120 rather than a wire and a half-pin (a), by the end of the fixation period the device assembly will include two supports: a one-third ring and a two-thirds ring

ring support. Moderate distraction is created between the supports: I,5-11 ↔ VII,3-9. For temporary fixation of fractures of the middle and distal thirds of the humeral diaphysis, the following devices are used: II,5-11 ↔ VII,3-9 and III,6-12 ↔ VIII,3-9, respectively. The “fixation” variant of external fixation has advantages over skeletal traction: it is less bulky, the patient is more mobile, and reduction may be achieved using both skeletal traction (elastic traction) and external fixation which enables dismantling of the device. After the final radiographs have been obtained to confirm the positions of the fragments, the arm is placed in abduction at an angle of 45–60◦ using a

wedge-shaped pillow and the patient is transported to the ward.

2.2.3

Distal Humerus (13-)

Ilizarov external fixation of fractures 13- starts with insertion of the intercrossing proximal basic wires into the upper third of the humerus. One wire is inserted in the sagittal plane and the other at an angle of 30◦ to it: III,6-12 and III,1-7. The proximal basic support is a two-thirds ring placed at level III of the upper arm and oriented relative to the bone and soft tissue. After tensioning, the wires III,6-12 and III,1-7 are fixed to the proximal basic support. At level V an intermediate ring is installed and connected by three rods to the proximal

2.2 Fractures of the Humerus

1

2

6

5

4

4

1

2

5

6

3

139

4

II,11,110; III,8,90 —— IV,9,90; V,4-10 —— VI,7,90 —— VIII,3-9

III,6-12; III,1-7 —— V,4-10 —— VII,9-3; VIII,3-9; VIII,8-2

Fig. 2.2.13. CEF device for fixation of segmentary fractures 12-C2.1. It is very important to ensure that the proximal and distal basic supports are installed perpendicular to the anatomical axis of the bone fragments to which they are fixed

Fig. 2.2.14. Ilizarov external fixation device for fixation of fracture 13-A3.1

2/3 150

140

140

2/3 140

basic ring.When the proximal basic support is properly installed the connection rods are parallel to the axis of the proximal bone fragment. In cases of extraarticular fractures (13-A2, 13-A3), as well as a slipped epiphysis and osteoepiphysis, two wires are inserted through the distal fragment strictly perpendicular to its longitudinal axis. One is inserted in the frontal plane and the other at an angle of 30◦ to it: VIII,3-9 and VIII,8-2. After tensioning the wires are fixed to a three-quarter ring external support. The distal basic support is connected to the intermediate ring by three rods. Distraction is then applied to create an interfragmental diastasis of 4–5 mm if this was not done by skeletal traction. Radiographs in two standard planes are obtained or an image intensifier is used. To eliminate residual displacement of the proximal fragment a reductionally fixing wire is inserted at the level of the intermediate ring. To avoid injury to the great vessels and nerves,only safe positions as specified in the atlas for level IV of the upper arm are used. Figure 2.2.14 shows, as an example, the wire V,4-10. The distal fragment is reduced using a stop and/or arched bending of the wire. If required, reduction is

2/3 150

150

3/4 150

achieved by displacement of the external supports. Large splinters are fixed using Kirschner wires with stops or console wires with stops. It is also beneficial to perform external fixation of intraarticular fractures of the distal humerus (injuries 13-B and 13-C) under conditions of skeletal traction on the orthopaedic traction table. However, it should be born in mind that tension to the collateral ligaments of the elbow joint as a result of excessive traction can aggravate displacement of the fragments. In fractures 13-B and 13-C, closed external fixation can only be performed when it is possible to recover joint congruity by moderate skeletal traction or by manual techniques (including the use of a thin hook or an awl). Fluoroscopy considerably facilitates the manipulation. If closed reduction fails, it is necessary to use open reduction. After the fragments of the condyle of the humerus have been properly put together, they are fixed by wires with stops inserted head to head. To eliminate residual displacement of the proximal fragment and to ensure its stable fixation, a reduction wire is inserted at the level of the intermediate ring. Figure 2.2.16 shows, as an example, the wire V,10-4. In intraarticular fractures accompanied by injury to the collateral ligaments, with apparent haemarthro-

140

2 Specific Aspects of External Fixation

a

Fig. 2.2.15a,b. CEF device for fixation of fracture 13-A3.3 (a). Support III,6-12 can be dismantled 2–3 weeks after surgery. Thus, the device assembly during the later stages of fixation includes only two supports (b). The distal support can be assembled as follows: VII,3-9; VIII,4,90; VIII,8,120 (Fig. 2.2.12). In this case transosseous elements VIII,4,90 and VIII,8,120 are cantilevered 3-mm wires or 4-mm half-pins. Wire VII,3-9 (or VII,9-3) is inserted directly above the fracture level. It is possible to use wire VII,3-9 (or VII,9-3) as a reduction wire to move the distal fragment within the limits of the thickness of the cortex. If the displacement of the distal bone fragment exceeds this value, the fragment is reduced by moving the distal support relative to the module fixing the proximal bone fragment

b 1

4

6

5

2

3

III,6-12 —— V,10-4; VI,8,70 —— VII,8,115; VIII,3-9; VIII,8-2 (a) 2/3 150 140 3/4 140 V,10-4; VI,8,70 —— VII,8,115; VIII,3-9; VIII,8-2 140

1

(b)

3/4 140

2

5

3

4

1

4

150

150

5

2

3

6

7

III,6-12; III,1-7 —— V,10-4 —— VIII,3-9; VIII,8-2

IV,4-10 —— VI,8,90 —— VII,8,110; VIII,3-9; VIII,8-2 —◦— III,3-9; IV,6,70

Fig. 2.2.16. Ilizarov external fixation device for fixation of fracture 13-C1.3

Fig. 2.2.17. Ilizarov external fixation device for fixation of fracture 13-C2.2

2/3 150

150

3/4 150

3/4 150

3/4 120

2.3 Fractures of the Forearm

sis, as well as in open fractures, the elbow joint must be temporarily immobilized after open reduction. To achieve this a single-support module is applied to the forearm and connected to the main device by three hinges as shown in Fig. 2.2.17. When it is impossible to perform full external fixation, for example in the event of the mass admission of casualties, the fracture can be immobilized by a “fixation” device. This type of external fixation can be used when it is temporarily impossible to perform an open reduction. The wire IV,4-10 is tensioned and fixed to the ring support. A second wire is inserted through the base of the olecranon (olecr.,9-3). This wire is fixed after tensioning to a three-quarter ring support. The forearm is placed in ﬂexion at an angle of 90–100◦ and fixed in this position with a sling. Moderate distraction is applied between the supports: IV,4-10 ↔ olecr.,9-3. Later the device can be converted to a full assembly. The “fixation” variant of external fixation has advantages over skeletal traction: it is less bulky and the patient is more mobile. Compared to the use of plaster immobilization, injured soft tissue can be more readily prepared for open intervention. After the final radiographs have been obtained, the patient is transported to the ward.

2.3

Fractures of the Forearm

In Ilizarov external fixation of the forearm (Figs. 2.3.1– 2.3.23), wires with a diameter of 1.5 mm are used. In CEF, wires with a diameter of 1.8–2 mm are used as the basic wires together with half-pins with a diameter of 4 mm. Also, the external fixation set must include 2-mm hinge (cantilever) wires with stops such that the insertion ends are of various lengths (5, 10, 15 and 20 mm). As a rule, in external fixation of the forearm, the device is assembled from supports of the same diameter. In order to allow ﬂexion of the elbow, the supports placed at levels 0, I and II of the forearm must be open (i.e. two-thirds or three-quarter rings). In external fixation of juxtaarticular and intraarticular fractures (21and 23-) the use of radiotransparent external supports is recommended. For insertion of transosseous elements at the first four levels of the forearm, through its front semicircle, the forearm is extended. For insertion of transosseous elements through the rear semicircle, the forearm is ﬂexed at 90–120◦ . For insertion of wires and half-pins through the ventral aspect of the forearm at the four distal levels, the hand is placed in dorsiﬂexion at 40◦ . For insertion of transosseous elements through the dorsal aspect of the forearm, the hand is placed in ventriﬂexion at 40◦ .

141

When it is impossible to change the articular position with these angles, the skin is displaced manually or using a thin hook in the direction of its natural displacement relative to the bone during movement of the adjacent joint. When using only reference positions for insertion of transosseous elements, there is no need to change the articular position. However, the technique of preliminary skin displacement (prior to insertion of transosseous elements) must be used in elongation of the segment, correction of deformities, bilocal osteosynthesis and in other situations when it is necessary to create a “store” of soft tissue. Before fixation of the wires, the external support must be appropriately oriented relative to the anatomical axis of the bone fragment and soft tissue.In external fixation the external supports must be placed perpendicular to the anatomical (mid-diaphyseal) axis of the bone fragment to which they are fixed. An exception is when the supports are intentionally placed in a position of hypercorrection (discussed below). The intermediate reductionally fixing supports on the forearm are oriented relative to the soft tissue depending on the way the bone fragments are to be reduced. If the technique of mutual displacement of the modules fixing the bone fragments is used, the distance between the inner edge of the ring and the back side of the forearm must be the same. When the positions of the bone fragments need to be changed using transosseous elements inserted near the bone wound,the ring should be displaced the necessary distance in the direction of the required displacement of the bone fragment. The residual displacement can be evaluated on comparison radiographs. This method of device assembly is more often used when the fragments are to be reduced over a certain time during the postoperative period (e.g. in traumatic deformities or in deformities arising from an orthopaedic pathology), rather than in a single stage on the surgical table. If the ends of the wires and half-pins that are at a certain distance from the support after it has been given the necessary spatial orientation are to be fixed using posts and/or gasket washers, the half-pins (unless they are basic or reductionally fixing transosseous elements) are fixed in the external support only after the necessary spatial orientation of the bone fragments has been achieved. If a half-pin is inserted in the bone not parallel to the external support, it is fixed to the support using two posts, one with a threaded hole (female) and the other with a threaded end (male). It is possible to fix a half-pin to a support or post using an L-shaped clip in a similar manner to fixation of a wire using a threaded slotted clamp. The next sections in which particular methods of fixation are described contain phrases similar to:

142

a

2 Specific Aspects of External Fixation

b

Fig. 2.3.1a,b. The proximal basic support on the forearm (a) is installed perpendicular to the anatomical axis of the proximal fragment of the ulna. An exception is the situation when there is an old injury to the ulna which involves only angular deformity. The proximal basic support is oriented relative to the soft tissue of the forearm such that the least distance between the inner edge of the ring and the skin along the anteroexternal aspect of the segment (plane of position 11 of the radius). The standard size of support must ensure the distance here is within 15 mm. The distance from the ulna to the support along the inner aspect (position 3) and along the outer aspect (position 9) must be equal. The distal basic support on the forearm (b) in isolated fractures of the radius is installed perpendicular to the anatomical axis of the distal fragment of the radius. In fractures of the ulna and in fractures of both bones of the forearm, the distal basic support is installed perpendicular to the anatomical axis of the distal fragment of the ulna. In all cases, at the level of the basic supports the distance from the rear surface of the ulna (plane of position 6) to the support must be equal

“When the device module is properly installed its connection rods are parallel to the anatomical axis of the bone fragment.” However, when the basic support is fixed only to wires, its position is likely to change (i.e. it is likely to warp) due to bending of the wires from the weight of the basic ring and the reductionally fixing ring connected to it. In such cases to control the orientation of the module, it should be supported by hand to prevent the bending of the wires. It should be born in mind that all the diagrams illustrating osteosynthesis give the direction of insertion of reductionally fixing elements (wires, half-pins), and the positions of the stops of the wires in a conventional way, as examples. In practice one should be guided by the actual residual displacement of the bone fragments. To avoid injury to the great vessels and nerves, the safe positions given in the atlas of part 1 should be used for insertion of reductionally fixing transosseous elements.The size of the external supports in the diagrams is also shown conventionally. In reduction using wires displacement of the bone fragments is controlled by means of a stop, but due to the ﬂexibility of wires (Fig. 1.6.9), half-pins are more often used for reduction which is achieved by “pushing” or “pulling”; if posts with a stop are use reduction can only be achieved by “pushing” (Fig. 1.6.10). In addition, any technique can be used when reduction is achieved by mutual displacement of the external supports (Figs. 1.6.4–1.6.8). Large splinters are reduced and fixed by wires with stops or by a hinge

(cantilever) with stops (Fig. 1.6.13). If the splinter is located in the interosseous space or there are great vessels and nerves in its path, a fork pin is used. In contrast to the fork pin shown in Figs. 1.4.8 and 1.6.14, the fork pin for use in the forearm is based on a 2-mm wire. Regional anaesthesia is generally used for external fixation of the forearm. Before external fixation of isolated fractures of the ulna, except fractures of the proximal and distal parts, the bone fragments are roughly reduced by skeletal traction. This can be achieved using the standard devices available with the orthopaedic traction table. When the necessary structure is not available, a reductionally fixing post must be specially produced (Fig. 2.3.2). Transport immobilization is removed on the surgical table after induction of anaesthesia. When the device described by Syssenko and its analogues are used, wire olecr.,3-9 is inserted through the olecranon. The wire is tensioned and fixed to the proximal support of the reductionally fixing post. A second wire is inserted through metacarpals II and V: m-carpII–mcarpV.This wire is tensioned and fixed to the distal support of the post.When the modified device described by Demianov is used,only one wire is inserted through the metacarpals. Irrespective of the fracture level, the forearm is placed in the mid-position between supination and pronation. Distraction is applied sufficient to eliminate the longitudinal displacement of the fragments.

2.3 Fractures of the Forearm

143

a

c

b

Fig. 2.3.2a–c. Reduction posts for the forearm: a The Russian Ilizarov Research Center, b K. U. Kudzaev, c Modified device of V. M. Demianov

To facilitate elimination of lateral and angular displacements a diastasis of 3–4 mm is created. X-ray contrast markers (injection needles, wire fragments) are placed on the skin and comparison radiographs are obtained in two standard planes, or ﬂuoroscopy is used. On the basis of the data obtained, if necessary additional correction to the positions of the bone fragments in the reductionally fixing post is performed. Lines corresponding to the anatomical axis of each bone fragment are drawn on the skin of the front and rear aspects of the segment. Using the special device shown in Fig. 1.8.2, the levels for insertion of the transosseous elements are marked. When sufficient clinical experience has been accumulated, comparison radiographs during skeletal traction are obtained only in cases of juxtaarticular and intraarticular fractures of the distal part of the forearm (23-). After this the field of operation is treated and draped.

The aim of external fixation of closed fractures is to achieve accurate radiographically confirmed reduction of the bone fragments on the surgical table. The device should be assembled carefully in the operating room whenever possible, as a hastily assembled device not assembled in the operating room may result in a poor outcome. In some rare cases, the patient may need daily treatment as an outpatient with radiographically monitored stepwise manipulations.Exceptions to this are those treated with the “fixation” device; the indications for the use of this device are discussed below. After external fixation of fractures of the radius and of both bones of the forearm, it is not advisable to strive for complete rotation of the forearm during the fixation period. If the ulna and radius are fixed separately, the rigidity of the osteosynthesis is decreased and there is a higher risk of damage to the soft tissues and infectious complications. However, there are positions that allow partial restoration of rotational

144

2 Specific Aspects of External Fixation

a

b

II,4-10; III,10-4 1/2 120

(a)

III,4-10; IV,6-12(IV,6-12) (b) 120

Fig. 2.3.3a,b. Variant devices for external fixation of fracture 21-B1.1

function during the fixation period (Table 1.3). That is why reference positions designated in the atlas of part 1 by → and — symbols are used for external fixation of the radius and of both bones of the forearm.

2.3.1

Proximal Forearm (21-)

In juxtaarticular fractures of the proximal metaphysis of the ulna (21-A1) and of the olecranon (21-B1), the choice of external fixation method is largely dependent on the character of the fracture surface. Before fixation, the forearm is placed in the position of maximum extension to relax the triceps muscle of the upper arm. If there is the possibility of an end stop between the fragments (damage 21-A1.2 and 21-B1.1), the olecranon is fixed with a thin hook and a wire is inserted through its top, the guiding end of the wire being oriented towards the back aspect of the ulna. The wire usually perforates the skin at level II or III of the forearm (pos. II,6 or III,6 of the ulna). A bending spiralshaped stop is formed on the central end of the wire. By rotation of the tensioning end of the wire, the stop is inserted to the bone. Comparison radiographs are

Fig. 2.3.4. External fixation device for fixation of fracture 21-B1.3

obtained in two standard planes. After confirmation of the reduction the wire is moved slightly proximally, cut off at the external edge of the stop and reinserted as far as the bone. Two wires with stops (II,4-10 and III,10-4) are then inserted through the ulna in the opposite direction in a plane close to the frontal plane. Both wires are strained in the half-ring that is oriented parallel to the plane of emergence of the compressing wire. After stabilization of the basic support the compressing wire is tensioned using a traction clip (Fig. 2.3.3a). If the line of the fracture of the olecranon goes downward and backward, the emergence of the compressing wire is oriented to the front aspect of the ulna. In this case it is strained in the ring support on the base of two wires, one of them inserted through the ulna and the other through both bones of the forearm.1 One of the wires is fixed after tensioning directly in the support and the second with the help of posts (Fig. 2.3.3b). 1

Bear in mind that, according to MUDEF, the indication for transosseous elements to be inserted through the radial bone is given in parentheses. If the wire is inserted through both bones simultaneously, it is designated in accordance with the priority with which the guiding end of the wire is inserted through the ulna and radius. For example, the designation VIII,6-12(VIII,6-12) is a wire with a stop inserted from the side of the ulna. The designation (VIII,12-6)VIII,12-6 is a wire without a stop inserted through both bones of the forearm from the side of the radius.

2.3 Fractures of the Forearm

145

Fig. 2.3.5. External fixation device for fixation of fracture 21-C2.2

Ilizarov external fixation of a splinter fracture of the olecranon (21-A1.3, 21-B1.2, 21-B1.3) starts with insertion of the basic wires, one of which is inserted through both bones: III,4-10 and IV,6-12(IV,6-12). The ring support is oriented perpendicular to the anatomical axis of the forearm. The proximal wire is strained and fixed directly to the support. Wire IV,6-12(IV,6-12) is fixed to the ring using posts. The forearm is placed in the position of maximum extension and the olecranon is temporarily stabilized with a thin hook.A wire with a stop to be inserted as far as the bone is inserted through the olecranon into the ulna medullary canal. Mutually crossing wires are inserted through the olecranon, one located in the frontal plane and the second at an angle of 30◦ to the first: olecr.,3-9 and olecr.,4-10. After tensioning these wires are fixed to a two-thirds ring. The wire inserted in the intramedullary canal is bent at a distance of 20 mm from the skin and its end is fixed to the proximal support (Fig. 2.3.4). After 2–3 weeks the wire can be removed. External fixation of isolated fractures of the proximal part of the radius (21-A2, 21-B2) and fractures of the proximal parts of both bones of the forearm (21A3, 21-B3, 21-C) involves immobilization of the elbow joint. A wire module is applied to the upper arm using a two-thirds ring for the distal support: IV,10-4; IV,8-2 — VII,3-9. Instead of a wire module based on two supports, a hybrid (wire–pin) module can be used based on a two-thirds ring: VI,7,120;VII,3-9. In fractures of the head and neck of the radius (21A2, 21-B2), a wire is inserted through the top third of the diaphysis: (IV,5-11). It is strained and fixed in the ring support. The basic supports of the upper arm and forearm are connected by hinges with the elbow bent at 90–100◦ and moderate distraction is applied. After obtaining a comparison radiograph, the problem of inserting the reductionally fixing wire, for example the post wire with a stop (II,9,90), is solved. It is fixed to the distal basic support using a post. The operation is completed by insertion of the second basic wire (III,3-9)

through the radius. The wire is also fixed to the basic support using posts. In fractures of the proximal parts of both bones of the forearm (21-A3, 21-B3, 21-C), after the support is mounted on the upper arm, the second support is mounted on the ulna and radius: III,4-10; IV,6-12(IV,6-12). The fracture of the olecranon is then fixed in the manner described above. The two modules are connected by hinges with the elbow bent at 90–100◦ and moderate distraction is applied. Reductionally fixing wires for the radius are inserted. In Fig. 2.3.5 this is wire (0,9,120). If it is impossible for various reasons to perform the full external fixation, the “fixation” variant of external fixation is performed. An external support is mounted on the upper arm and on the forearm. They are connected by three hinges and moderate distraction is applied. Here is a possible variant assembly: VI,7,120; VII,3-9 ←o→ III,4-10; IV,6-12(IV,6-12). If an external module is not applied on the upper arm, the arm is fixed with a sling with the elbow ﬂexed at 90–100◦, and the patient is transported to the ward.

2.3.2

Diaphyseal Fractures (22-)

2.3.2.1 Ulnar Diaphysis Proximal Third Ilizarov external fixation of isolated fractures of the proximal third of the ulnar diaphysis (injuries 22-A1.1, 22-A1.2, 22-B1.1, 22-B1.2, 22-C1.1) starts with insertion of two intercrossing proximal basic wires at the level of the proximal metaphysis. One is inserted through the ulna in a plane close to the frontal plane and the other is inserted through both bones: I,2-8 and I,5-11(I,5-11). A distal basic wire (VII,4-10) is then inserted through the ulna at the level of the distal metaphysis in a plane close to the frontal plane. The proximal basic support,a three-quarter ring,is ori-

146

2 Specific Aspects of External Fixation

ented relative to the anatomical axis of the ulna relative to the soft tissue. The wires are tensioned and fixed to the support. An intermediate reductionally fixing ring support is then installed at level IV of the forearm and connected by three rods to the proximal support. The intermediate support is connected by three rods to the distal basic support. The nuts of the connection rods at the intermediate support are not tightened. The distal basic support is installed so that it is perpendicular to the anatomical axis of the distal bone fragment. The distances between the posterior aspect of the ulna and the supports at the levels of the basic support locations must be equal. After tensioning wire VII,4-10 is fixed to the distal basic support installed in this way. The nuts are tightened at the intermediate support, and distraction is then applied to create an interfragmentary diastasis of 3–4 mm.Two standard radiographs are obtained or an image intensifier is used. To eliminate residual displacement of the proximal bone fragment at level II, a reductionally fixing wire is inserted. To eliminate residual displacement of the distal fragment at level IV, a second reductionally fix-

2

1

4

6

5

I,2-8; I,5-11(I,5-11); II,10-4 —— III,6,120; IV,3-9 3/4 130

130

7

3

—— VII,4-10; VII,6-12(VII,6-12) 130

Fig. 2.3.6. External fixation device for fixation of fracture 22-B1.1

ing wire is inserted. The direction of insertion of these wires and the locations of their stops depend on the residual displacement of the bone fragments. To avoid damage to the great vessels and nerves, only the safe positions identified in the atlas of part 1 for levels II and IV of the forearm (relative to the ulna) are used. As an example, Fig. 2.3.6 shows wires II,10-4 and IV,39. Wire II,10-4 is fixed to the proximal support using posts. By displacement of the bone fragment with the help of a stop, or arched bending of the wire, the proximal bone fragment and then the distal bone fragment are reduced successively. It is also possible to use any reduction technique together with mutual displacement of the external supports.After elimination of the lateral and angular displacement of the fragments the supports are brought closer to eliminate the diastasis. If it is possible to ensure axial compression (transverse or short oblique fracture line) a second basic wire VII,5-11 is inserted through the ulna. If it is considered necessary to apply head cross compression (oblique, spiral fractures) or neutral osteosynthesis (splintered destruction), a second distal basic wire is inserted through both bones of the forearm: VII,6-12(VII,6-12). Large splinters are reduced and fixed using wires with stops or console wires with stops. Middle Third Ilizarov external fixation of fractures of the middle third of the ulnar diaphysis (injuries 22A1.1, 22-A1.2, 22-B1.1, 22-B1.2, 22-C1.1) starts with insertion of intercrossing proximal basic wires, one of which is inserted through both bones of the forearm: I,2-8 and I,5-11(I,5-11). The distal basic wire is then inserted through the ulna: VIII,5-11. The proximal support, a three-quarter ring, is oriented relative to the anatomical axis of the ulna, relative to the soft tissues. The proximal basic wires are then tensioned preliminarily and fixed to the support. At level III (or level IV, depending on the fracture location), an intermediate (reductionally fixing) support is installed and is connected by three rods to the proximal basic support. For proper orientation of the supports, the connection rods must be parallel to the anatomical axis of the proximal bone fragment.At level V (or level VI, depending on the fracture location) the second reductionally fixing ring support is installed and connected by three rods to the proximal reductionally fixing support and by three rods to the distal basic support. The nuts of the connection rods at the second reductionally fixing support are not tightened. The distal basic support is installed so that it is perpendicular to the anatomical axis of the distal bone fragment. The distances from the posterior aspect of the ulnar bone to the support at the levels of the basic

2.3 Fractures of the Forearm

2

1

4

6

147

5

I,4-10; I,5,90(I,5,90); II,10-4 —— III,6,110; IV,7,90 —— 3/4 130

8

130

7

3

VII,6,120; VIII,5-11; VIII,6-12(VIII,6-12)

(a)

130

I,4-10; I,5,90; II,10-4 —— IV,7,90 —— VII,6,110 3/4 130

a

b

1/2 130

1/2 130

(b)

Fig. 2.3.7a,b. CEF device for fixation fracture 22-B1.2. Wire VIII,5-11 is removed on the surgical table immediately after radiographic confirmation of fragment reduction. Transosseous element I,5,90(I,5,90) is a 2–3-mm wire inserted from the front cortical plate of the radius through both bones only as far as the outlet of its guiding end (a). This wire is tightened 2–3 weeks after surgery so that it stays only in the ulna. At the same time, wire VIII,6-12(VIII,6-12) is removed. The front half-rings (b) are dismantled at the intermediate and distal basic rings. From this point, recovery of rotational movements of the forearm can start

supports must be equal. After tensioning, wire VIII,511 is fixed to the distal basic support installed in the manner described. The device is stabilized and distraction is applied to produce an interfragmentary diastasis of 3–4 mm. Radiographs are obtained in two standard planes or an image intensifier is used. To eliminate residual displacement of the proximal bone fragment, a reduction wire is inserted at level IV (or level III, depending on the line of fracture). To eliminate residual displacement of the distal fragment, a second reduction wire is inserted at level V (or at level VI). Figure 2.3.8 shows, as an example, the wires III,9-3 and V,4-10. Using a stop or arched bending of the wire,the proximal bone fragment and then the distal bone fragment are reduced successively.It is also possible to use any reduction technique together with mutual displacement of the external supports.The diastasis between the fragments is eliminated. If it is possible to ensure axial interfragmentary compression (transverse or short oblique fracture line), a second basic wire VII,4-10 can be inserted through the ulna and fixed to the distal support using posts. If it is considered necessary to apply head cross compression (oblique, spiral fractures) or neutral osteosynthesis (splintered destruction), a second distal basic wire is inserted through both bones of the forearm: VIII,612(VIII,6-12).

2

1

4

5

130

130

I,2-8; I,5-11(I,5-11) —— III,9-3 —— V,4-10 3/4 130

6

3

—— VIII,5-11; VIII,6-12(VIII,6-12) 130

Fig. 2.3.8. External fixation device for fixation of fracture 22-A1.1

148

2 Specific Aspects of External Fixation

2

2

4

6

7

5

I,4-10; I,5,90(I,5,90); II,10-4 —— IV,6,90; V,5,80 —— VI,6,90 —— 3/4 130

9

130

130

8

3

VII,6,120; VIII,5-11; VIII,6-12(VIII,6-12)

(a)

130

I,4-10; I,5,90; II,10-4 —— IV,6,90; V,5,80 —— VI,6,90 3/4 130

—— VII,6,120 1/2 130

a

b

1

2

4

5

6

120

7

3

1/2 130

(b)

Fig. 2.3.9a,b. CEF variant device for fixation of fracture 22-C1.1. During insertion of half-pin IV,6,90 into the intermediate fragment, the latter is retained by a thin hook or a towel clip. Wire VIII,5-11 is removed on the surgical table immediately after radiographic confirmation of fragment reduction (a). Wire I,5,90(I,5,90) is tightened 3– 4 weeks after surgery so that it stays only in the ulna: I,5,90 (b). At the same time wire VIII,6-12(VIII,6-12) is removed. The front half-rings (b) of the reductionally fixing and distal basic rings are dismantled. From this point, gradual recovery of the rotational movements of the forearm can start

II,2-8; II,4-10 —— V,10-4; VI,11-5 —— 3/4 120

1/2 130

VII,10-4; VIII,5-11; VIII,6-12(VIII,6-12) 120

Fig. 2.3.10. Ilizarov external fixation device for fixation of fracture 22-B1.1

Distal Third Ilizarov external fixation of fractures of the distal third of the ulnar diaphysis (injuries 22-A1.1, 22-A1.2, 22-B1.1, 22-B1.2, 22-C1.1) starts with insertion of intercrossing proximal basic wires through the ulna: II,2-8 and II,4-10.The distal basic wire VIII,5-11 is then inserted through the ulna. The proximal support, a three-quarter ring, is oriented relative to the anatomical axis of the ulna, relative to the soft tissues. The proximal basic wires are then tensioned preliminarily and fixed to the support. The reductionally fixing ring support is then installed at level V of the forearm and connected by three rods to the proximal support. The connection rods must be parallel to the axis of the proximal fragment of the ulna. The intermediate support is then connected to the distal basic support. At the levels of the basic supports, the distances from the posterior aspect of the ulna to the supports must be the same. After orientation of the distal basic support relative to the anatomical axis of the distal fragment of the ulnar bone, wire VIII,2-8 is tensioned and fixed to it. Distraction is applied to produce an interfragmentary diastasis of 3–4 mm if this could not be done by skeletal traction.Radiographs are obtained in two standard planes or an image intensifier is used. To eliminate residual displacement of the proximal bone fragment at level V, a reductionally fixing wire is inserted. To eliminate residual displacement of the distal fragment at level VII, a second reductionally fixing wire is inserted. The direction of the insertion of these wires and the location of their stops depend on the

2.3 Fractures of the Forearm

2

1

4

149

6

II,4-10; II,6,90(II,6,90) —— V,6,90; IV,6,70 —— 5

3/4 130 3

130

7

VII,6,90; VIII,2-8; VIII,6-12(VIII,6-12)

(a)

130

I,4-10; II,6,90 —— V,6,90 —— VII,6,90; VIII,6,120 3/4 130

a

b

1/2 130

1/2 130

(b)

Fig.2.3.11a,b. CEF device for fixation of fracture 22-B1.2. Wire VIII,2-8 is removed on the surgical table after fragment reduction. Transosseous element II,6,90(II,6,90) is a 2-mm wire inserted from the front cortical plate of the radius through both bones only as far as the outlet of its guiding end (a). This wire is tightened 2–3 weeks after surgery so that it stays only in the ulna. Wire VIII,6-12(VIII,6-12) is cut off on the side of the ulna and pulled dorsally so that it stays only in the ulna. If this manipulation indicates that this wire provides insufficient strength of fixation of the bone, it is replaced with halfpin VIII,6,110. At the same time wire VIII,2-8 is removed. The front half-rings (b) of the intermediate and distal basic supports are dismantled. From this point, recovery of the rotational movements of the forearm can start

residual displacement of the bone fragments. To avoid damage to the great vessels and nerves only the safe positions identified in the atlas of part 1 for levels V and VII of the forearm (relative to the ulna) are used. As an example, Figure 2.3.10 shows wires V,10-4 and VII,10-4. Wire VII,10-4 is fixed to the distal support using posts. After elimination of the lateral and angular displacement of the fragments, the proximal and distal supports are brought closer to eliminate the diastasis. Monteggia Fractures External fixation of Monteggia fractures (22-A1.3, 22-B1.3, 22-C1.1) is preceded by an attempt to reset the head of the radius. While an assistant holds the shoulder, with one hand the surgeon performs traction holding the unbent forearm, pronating it and moving it at the elbow joint, and with the other hand presses upon the head of the radius in an inward and backward direction. After resetting, the forearm is placed in extreme supination. The head of the radius is fixed to the radial bones by a wire with a stop: (I,115)I,11-5. On completion of the operation, to reduce the risk of pin-tract infection and elbow joint stiffness, it is recommended that wire (I,11-5)I,11-5 with post or halfpin (I,9,90) be replaced (Fig. 2.3.12). If resetting of the head of the radius is confirmed radiographically, external fixation is performed following a method similar to those described for isolated ulnar fractures. If the head of the radius cannot be reset manually, skeletal traction is applied by means of a reductionally fixing post, and an anteroposterior radiograph is assessed. If the interrelationships of the distal radial joint

1

4

5

3

6

I,4-10; (I,9,90); II,10-4 —— IV,6,90; (V,2-8) 3/4 130

130

2

—— VIII,5-11 130

Fig. 2.3.12. External fixation device for fixation of Monteggia fractures (22-A1.3)

150

1

2 Specific Aspects of External Fixation

3

4

6

5

I,4-10; (I,11-5)I,11-5; (II,9,90) —— (III,10,120); (IV,5-11) 3/4 130

130

7

2

—— VII,6-12(VII,6-12); (VII,1-7) 130

Fig. 2.3.13. External fixation device for fixation of fracture 22-B2.1

are not impaired, wire VIII,6-12(VIII,6-12) is inserted through both bones of the forearm in the sagittal plane. When the ulnar fracture is located in the upper third of the diaphysis, the distal basic wire is inserted at level VII: VII,6-12(VII,6-12). The proximal basic wire is inserted only through the ulnar bone: I,4-10. The device is assembled with three supports for fractures of the proximal or distal thirds of the ulnar diaphysis, and with four external supports (two basic and two reductionally fixing) for fractures of the middle third of the ulnar diaphysis. After the device has been assembled, distraction sufficient to place the head of the radius exactly opposite the radial incisure is applied. The end-point may be recovery of the anatomical length of the ulna. If comparison radiographs reveal impaired interrelationships of the distal radial joint as well, the assembly of the external fixation device has certain features. All supports of the device are connected by solid rods. Wire (V,2-8) is inserted through the radius and fixed after tensioning to the intermediate support using posts.The distance between the proximal basic support and the reductionally fixing support is increased by an amount sufficient to pull through the head of the radius. For final resetting and fixation of the head of the radius, wire with a stop (I,11-5)I,11-5 is inserted through

both bones of the forearm. If lateral displacement is present, the use of wire (I,3-9) or (I,9-3) is recommended. With the use of the stop the lateral displacement of the proximal part of the radius is eliminated. The wire is then bent backwards and inwards. The dislocation is eliminated by simultaneous traction at both ends of the wire.After the manipulation wire (I,39) is substituted for wire (I,11-5)I,11-5 or for half-pin I,9,90. The ulnar fragments are then reduced and fixed by one of the above methods. If the second variant of the device assembly (solid rods between the supports) is used,elimination of longitudinal displacement of the ulnar fragments is achieved by distraction between the intermediate and distal basic supports. In the distal support a strained wire must be inserted only through the ulnar bone, for example VIII,5-11 (Fig. 2.3.12). After comparison radiographs have been obtained the device for skeletal traction is dismantled. The arm is fixed by means of a sling with the elbow ﬂexed at 90–100◦ . Two pins fixed to the distal support with a gauze sling between them ensure the mid-physiological position of the hand. 2.3.2.2 Radial Diaphysis Irrespective of the level of the radial diaphysis fracture before external fixation,the forearm in skeletal traction is placed in the mid-physiological position: the forearm is maximally supinated and then the internally rotated to 65–70◦ . External fixation of fractures of the proximal third of the radial diaphysis (injuries 22-A2.1, 22-A2.2, 22B2.1,22-B2.2,22-C2.1) starts with insertion of the proximal basic wire I,4-10 through the ulna at the level of the proximal metaphysis in a plane close to the frontal plane. The distal basic wire (VII,1-7) is then inserted through the radius at the level of the distal metadiaphysis in a plane close to the sagittal plane. The proximal support, a three-quarter ring, is installed perpendicular to the anatomical axis of the ulna; the support is oriented relative to the soft tissues, tensioned and the wire is fixed in it. The intermediate reductionally fixing support is then installed at level IV of the forearm and connected by three rods to the proximal basic support. The intermediate support is connected by three rods to the distal basic support. The nuts of the connection rods at the intermediate support are not tightened. The distal basic support is installed so that it is perpendicular to the anatomical axis of the distal bone fragment. The distance from the posterior aspect of the ulna (line of position 6) to the support at the levels of the basic supports must be equal. After tensioning wire (VII,1-7) is fixed to the distal support installed in the way de-

2.3 Fractures of the Forearm

scribed. The device is stabilized by tightening the nuts at the rods. Distraction is applied to create an interfragmentary diastasis of 4–5 mm if this was impossible by skeletal traction. After that the rotational displacement of the proximal fragment of the radial bone is eliminated according to the method of Ilizarov et al. [6]. A 2-mm console wire II,10,90 is inserted in the proximal fragment of the radial bone at a distance of 20–25 mm proximal from the fracture level through both cortical layers. Using this wire as a lever, the proximal splinter is rotated first toward the outside up to the stop and then 90◦ towards the inside. In this position in Ilizarov external fixation, the second proximal basic wire is inserted through both bones of the forearm: (I,11-5)I,11-5. The wire is tensioned and fixed to the proximal support. The console wire lever is removed. Radiographs are obtained in two standard planes or an imaging intensifier is used. To eliminate residual displacement of the proximal bone fragment by the Ilizarov method, a reductionally fixing wire is inserted at level II. Insertion of Kirschner wires through the radial bone at this level is dangerous due to the possibility of damaging great vessels and nerves. Therefore, it is best to use a console wire with a stop or a 4-mm half-wire. Figure 2.3.13 shows, as an example, console wire II,9,90. It is fixed to the proximal support using a post. To eliminate residual displacement of the distal fragment at level IV, a second reductionally fixing wire is inserted. Possible variants of the wire insertion are selected on the basis of the residual displacement of the distal bone fragment using the safe positions of the atlas in part 1 for level II of the forearm (relative to the radius). Figure 2.3.13 shows wire (IV,5-11) as a possible variant. By repositioning the bone fragment using a stop together with arched bending of the wire, the proximal and then the distal bone fragments are successively reduced. It is also possible to use any reduction technique together with mutual displacement of the external supports.After elimination of the lateral angular displacement of the fragments, the proximal and distal supports are brought closer to eliminate the diastasis together with moderate compression in transverse and short oblique fractures. If it is considered necessary to apply head cross compression (oblique, spiral fractures) or neutral osteosynthesis (splintered destruction), a second distal basic wire VII,6-12(VII,6-12) is inserted through both bones of the forearm in the sagittal plane. Large splinters are reduced and fixed using wires with stops or console wires with stops. Ilizarov external fixation of fractures of the middle third of the diaphysis of the radial bone (injuries 22-A2.1, 22-A2.2, 22-B2.1, 22-B2.2, 22-C2.1) starts with

3

1

4

151

6

5

I,4-10; I,5,90(I,5,90); (II,9,90) —— (III,10,110); (IV,11,90) 3/4 130

130

2

7

—— (VII,1-7); VII,6-12(VII,6-12) 130

Fig. 2.3.14. CEF device for fixation of fracture 22-B2.1. The proximal basic wire must have a stop: I,4-10. To prevent stiffness of the elbow joint and pin-tract infection, the proximal fragment of the radius is stabilized preferably with a console wire inserted through both bones: I,5,90(I,5,90). To reduce the distal fragment, it is also possible to use a console transosseous element, for example IV,11,90. As wire VII,612(VII,6-12) is inserted in oblique and splintered fractures, wire (VII,1-7) must be removed immediately after reduction of the fragments

insertion of a proximal basic wire through the ulnar bone: I,4-10.A distal basic wire is then inserted through the radial bone: (VIII,1-7). The proximal basic support, a three-quarter ring, is oriented relative to the anatomical axis of the ulnar bone, relative to the soft tissues, and then the tensioned wire is fixed to it. At level III (or level IV, depending on the location of the fracture) an intermediate (reductionally fixing) support is installed and connected by three rods to the proximal basic support. At level V (or level VI, depending on the location of the fracture) a second reductionally fixing ring support is installed and connected by three rods to the proximal reductionally fixing support and by three rods to the distal basic support. The nuts of the connection rods at the second reductionally fixing support are not tightened. The distal basic support is installed so that it is perpendicular to the anatomical axis of the distal bone fragment. The distances from the posterior aspect of the ulna to the supports at the levels of the basic supports must be the same. After tension-

152

2 Specific Aspects of External Fixation

3

1

4

I,4-10; (I,11-5)I,11-5 —— (III,5-11) —— 3/4 130

5

130

2

6

3

1

4

6

7

I,4-10; I,5,90(I,5,90) —— (III,8,90) —— (V,3-9); (VI,12,80) 3/4 120 5

120

8

120

2

(V,9-3) —— (VIII,1-7); VIII,6-12(VIII,6-12)

—— (VII,10,90); VIII,6-12(VIII,6-12); (VIII,1-7)

Fig. 2.3.15. Ilizarov external fixation device for fixation of fracture 22-A2.1

Fig. 2.3.16. CEF device for fixation of fracture 22-C2.1. During insertion of wire (V,3-9) through the intermediate fragment, the latter is retained by a thin hook or a towel clip. Wire (VIII,1-7) can be removed on the surgical table immediately after radiographic confirmation of fragment reduction

130

130

ing, wire (VIII,1-7) is fixed to the distal basic support installed in the manner described. The device is stabilized and distraction is applied to create an interfragmentary diastasis of 3–4 mm. After that the rotational displacement of the proximal fragment of the radial bone is eliminated according to the method of Ilizarov et al. [6] and the wire (I,11-5)I,11-5 is inserted through both bones. Radiographs are obtained in two standard planes or an image intensifier is used. To eliminate residual displacement of the proximal bone fragment at level IV (or depending on the line of fracture, level III) a reduction wire is inserted. To eliminate residual displacement of the distal fragment at level V (or level VI), a second reduction wire is inserted. Figure 2.3.15 shows, as an example, the wires III,5-11 and V,9-3. By known techniques (repositioning using a stop or bending of the wire), the proximal and then the distal bone fragments are successively reduced. It is also possible to use any reduction techniques together with mutual displacement of the modules fixing the bone fragments. After that the diastasis is eliminated. If the line of the fracture makes it possible to compress the fragments axially (transverse or short oblique

120

fractures), the second distal basic wire VIII,1-7 can be inserted through the radius. If it is considered necessary to apply head cross compression (oblique, spiral fractures) or neutral osteosynthesis (splintered destruction),a second distal basic wire is inserted through both bones of the forearm: VIII,6-12(VIII,6-12). Large splinters are fixed using wires with stops or console wires with stops. Ilizarov external fixation of fractures of the distal third of the radial diaphysis (injuries 22-A2.1, 22-A2.2, 22-B2.1, 22-B2.2, 22-C2.1) starts with insertion of the proximal basic wire I,4-10 through the ulna. The distal basic wire (VIII,1-7) is then inserted through the radius. The proximal support, a three-quarter ring, is oriented relative to the anatomical axis of the ulna, relative to the soft tissues, and the preliminarily tensioned wire is fixed to the support. The intermediate ring support is then installed at level V of the forearm and connected by three rods to the proximal support. The connection rods between the intermediate and proximal basic supports must be

2.3 Fractures of the Forearm

3

1

4

6

I,4-10; (I,11-5)I,11-5 —— (V,9-3); (VI,2-8) —— 3/4 130

5

120

2

7

(VII,4-10); (VIII,1-7); VIII,6-12(VII,6-12) 120

Fig. 2.3.17. Ilizarov external fixation device for fixation of fracture 22-B2.1

parallel to the axis of the ulna. After that the intermediate support is connected by three rods to the distal support.At the level of placement of the basic supports, the distance from the posterior aspect of the ulna to the support must be the same. During tensioning of the wire in the distal basic support, the support must be located perpendicular to the anatomical axis of the distal fragment of the radial bone. Distraction is applied to create an interfragmentary diastasis of 3–4 mm. After that the rotational displacement of the proximal fragment of the radius is eliminated according to the method of Ilizarov et al. [6]. The second proximal basic wire is then inserted through both bones of the forearm: (I,11-5)I,11-5. After tensioning the wire is fixed to the proximal support. Radiographs are obtained in two standard planes or an image intensifier is used. To eliminate the residual displacement of the proximal bone fragment at level V, a reductionally fixing wire is inserted. To eliminate the residual displacement of the fragment at level VII, a second reductionally fixing wire is inserted. Figure 2.3.17 shows as an example wires V,9-3 and VII,4-10. Wire VII,4-10 is fixed to the distal support using posts. The proximal and then the distal bone fragments are successively reduced. After reduction of the frag-

153

ments,displacement edgewise and at an angle the proximal support and the distal support are brought closer to eliminate the diastasis, with moderate compression in transverse and short oblique fractures. If it is considered necessary to apply head cross compression (oblique, spiral fractures) or neutral osteosynthesis (splintered destructions), a second distal basic wire is inserted through both bones of the forearm: VII,6-12(VII,6-12). In a Galeazzi’s injury (22-A2.3, 22-B2.3, 22-C2.1), rupture of the ligaments of the distal radioulnar joint occurs with displacement of the distal fragment of the radius together with the hand towards the palmar or dorsal sides but the spatial location of the ulna does not change. Therefore, in closed reduction that must precede external fixation, the distal fragment of the radius is brought closer to the ulna and not vice versa. The same principle is followed for correction of the dislocation with the help of the device. For skeletal traction, the proximal basic support is mounted on a three-quarter ring: I,4-10; I,5,90(I,5,90). In the ﬂexion variant of Galeazzi’s injury, wire (VIII,17) is inserted through the radius; in the extension variant wire (VIII,7-1) is inserted. Depending on the level of the radial fracture, the device is assembled on the basis of three or four external supports. Distraction is applied to create an interfragmentary diastasis of 3–4 mm. In the same manner as was described for external fixation of isolated diaphyseal fractures of the radius, the bone fragments are reduced. The interfragmentary diastasis is eliminated and comparison radiographs obtained in two standard planes are evaluated. If the interrelationships in the distal radioulnar joint have not been restored, console wire VII,9,90 is inserted in the ulna in the ﬂexion variant or wire VII,4,90 in the extension variant. By bending wire (VIII,1-7) or (VIII,7-1) in an arc, the proper interrelations in the distal radioulnar joint are restored. Wire VIII,6-12(VIII,6-12) is then inserted through both bones of the forearm. Only then is the distraction force provided by the reductionally fixing post removed. The operation is completed by removal of the console wire at level VII. After comparison radiographs have been obtained, the device for skeletal traction is dismantled. The arm is fixed with a cravat bandage with the elbow ﬂexed at 90–100◦. Two pins with a gauze sling between them, to ensure the mid-physiological position of the hand, are fixed to the distal support of the device. 2.3.2.3 Diaphysis of the Radius and Ulna Irrespective of the level of fracture of the radial diaphysis before external fixation, the forearm in skeletal traction is placed in the mid-physiological position:

154

2 Specific Aspects of External Fixation

3

1

4

6

II,4-10; (II,9,90) —— (V,8-2); (IV,12,70) —— 3/4 130

130

5

2

7

(VII,10,7); (VIII,7-1); VIII,6-12(VIII,6-12) 130

3

1

(a)

4

II,4-10; (II,9,90) —— (V,12,90) ←→ 3/4 130 5

130

2

(VII,10,7); (VIII,7-1)

(b)

130

a

Fig. 2.3.18a,b. CEF devices for fixation of fractures 22-B2.2 (a) and 22-A2.2 (b). Half-pin (II,9,90) is used to eliminate rotational displacement and subsequent fixation of the proximal fragment of the radius. Wire VIII,6-12(VIII,6-12) is inserted after radiographic confirmation of reduction (a). Wire (VIII,7-1) is then removed. In transverse and short oblique fractures of the distal third of the radial diaphysis when axial compression can be applied, the wire joining the two bones at the level of their distal metaphysis (2) should not be used

b

the forearm is maximally supinated and then internally rotated 90◦ . The rotational displacement of the proximal fragment is eliminated by the method of Ilizarov et al. [6]. The algorithm for the implementation of the method is described in the section devoted to issues of external fixation of radial fractures. Ilizarov external fixation of fractures of both bones of the forearm (injuries 22-A3, 22-B3, 22-C1.2, 22-C1.3, 22-C2.2, 22-C2.3, 22-C3) starts with insertion of the proximal basic wire I,4-10 through the proximal metaphysis of the ulna in a plane close to the frontal plane. The proximal support, a three-quarter ring, is oriented relative to the anatomical axis of the ulna,relative to the soft tissues. The wire is then tensioned and fixed to the external support. If the radiographs obtained in skeletal traction show that the relations in the distal radioulnar joint are not disturbed, the distal basic wire VIII,612(VIII,6-12) is inserted through both bones. A second distal basic wire (VIII,1-7) is then inserted through the radius. Depending on the levels of the fractures of the ulna and radius, the device assembly includes up to three reductionally fixing rings. It should be remembered that an additional support considerably simplifies reduction of bone fragments. The reductionally fixing support(s) is (are) connected by three rods to the proximal basic support. For the device to be properly centred, the connection rods must be parallel to the anatomical axis of the proximal fragment of the ulna. The intermediate supports are then connected by three rods to

4

1

6

5

I,4-10; I,5-11(1,5-11) —— III,9-3; (IV,11-5) —— 3/4 120

7

120

2

8

3

VI,10-4; VII,4-10 —— (VII,1-7); (VIII,7-1) 120

120

Fig. 2.3.19. External fixation device of Ilizarov et al. [6] for fixation of fracture 22-A3.3

2.3 Fractures of the Forearm

155

Fig. 2.3.20a,b. CEF devices for fixation of fractures 22C2.2 (a) and 22-A3.3 (b). The proximal basic wire must have a stop: I,4-10. The second proximal basic wire is a console wire; it is inserted through both bones: I,5,90(I,5,90). In segmentary fractures (a) before insertion of transosseous elements through the intermediate fragment of the radius, it is temporarily fixed with a towel clip. b The variant according to Ilizarov et al. [6] of CEF with separate reduction of the ulna and radius is shown

a

b 1

3

1

4

6

4

10

5

8

9

7

2

I,4-10; I,5,90(I,5,90) —— III,7,90; (IV,10,90); IV,6,80 —— V,4-10; (V,12,110); (VI,1-7) —— (VII,10,90); VIII,6-12(VIII,6-12) (a) 3/4 130 130 130 130 6

5

7

2

8

3

I,4-10; I,5,90(I,5,90) —— III,9-3; (IV,1,70) —— V,7,90; VII,4-10 —— (VII,1-7); (VIII,7-1) 3/4 120

120

120

the distal basic support. The distal basic support must be installed perpendicular to the anatomical axis of the distal fragment of the radius. At the levels of the basic supports the distance from the posterior aspect of the ulna (position 6) to the support must be the same.With the distal basic support in this position, the wires are tensioned and fixed to it. Distraction is applied to create an interfragmentary diastasis of 3–4 mm. The rotational displacement of the proximal fragment of the radius is then eliminated by the method of Ilizarov et al. [6]. The manipulation is completed by insertion of a wire through the proximal metaphysis of both bones of the forearm: I,5-11(I,5-11). After tensioning the wire is fixed to the proximal support. Radiographs are obtained in two standard planes or an image intensifier is used. The residual displacements of the proximal and distal bone fragments of the ulna and radius are successively eliminated. The reduction wires are inserted at a distance of 20–30 mm from the fracture. To exclude damage to the great vessels and nerves only safe positions as identified in the atlas for insertion of transosseous elements for the relevant levels of the forearm are used. Large splinters are reduced and fixed using wires with stops or console wires with stops. If the comparison radiographs in skeletal traction show that the fragments of the ulna and radius need

120

(b)

different amounts of distraction (compression), the device assembly must allow the possibility of separate reduction of the forearm bones. As an example, Fig. 2.3.19 shows a diagram of external fixation of the fracture 22-A3.3 according to the method of Ilizarov et al. [6]. It follows from the Figs. 2.3.19 and 2.3.20b that to allow separate reduction the reductionally fixing and distal basic supports of the device must be connected by through rods. Both the distal basic and distal reductionally fixing wires through the distal fragment of the ulna are fixed to the intermediate support, and those through the radius are fixed to the distal support. Thus separate axial displacement of the fragments of the forearm bones is possible. In fractures of the lower third of the diaphysis of the forearm bones, two- or three-hole posts are used. In fracture of the forearm bones at different levels, the distal fragment of bone fractured at the lower level is fixed to the distal ring. After comparison radiographs have been obtained, the device for skeletal traction is dismantled. The arm is fixed with a cravat bandage with the elbow ﬂexed at 90–100◦. Two rods with a gauze hammock strung between them are fixed to the distal support of the device to place the hand in the mid-physiological position.

156

2.3.3

2 Specific Aspects of External Fixation

Distal Forearm (23-)

No preliminary skeletal traction by means of a special reductionally fixing device is required in fractures of the distal part of the forearm. The operation is preceded by a closed manual reduction of the bone fragments. After that the wire m/carpII–m-carpV is inserted through metacarpal bones II and V (bypassing metacarpal bones III and IV). The wire is tensioned and fixed to a half-ring or a two-thirds ring support. The wire can be inserted through metacarpal bones II, III, IV and V only after they have been forced into one plane. If the wire inserted through metacarpal bones II, III, IV and V is not removed at the end of the operation, it will cause pain and will negatively affect the function of the fingers. Firm fixation of the hand is provided by a support basis on the two wires m/carpII–m/carpIV and m/carpIII–m/carpV. For external fixation of isolated juxtaarticular fractures of the ulna (23-A1), a proximal basic wire with a stop is inserted through both forearm bones in the sagittal plane:V,6-12(V,6-12).The ring support is placed perpendicular to the anatomical axis of the proximal fragment of the ulna and oriented relative to the soft tissues so that the forearm at the level V is in the centre of the ring support. The wire is strained and fixed to the ring. An intermediate support is installed at level VIII of the forearm. The device is assembled such that the metacarpal bones are located in the same plane as the forearm bones, parallel to the connection rods. After mounting the external supports a distraction force is applied. On the basis of comparison radiographs, reductionally fixing wires, for example VI,4-10 and VIII,11-5, are inserted through the fragments of the ulna.The diastasis between the fragments is eliminated. In oblique or splintered fractures,a wire is then inserted through both bones of the forearm: VIII,6-12(VIII,612). If the fracture line allows axial compression, a halfpin or a 2-mm console wire VIII,8,110 is inserted. External fixation of injury 23-A1.2 is shown in Fig. 2.3.21. In transverse fractures the operation is completed by removal of the support from the hand. In splintered fractures with marked oedema of the soft tissues of the carpal joint area the support is removed in 2–2.5 weeks. In external fixation of extraarticular fractures of the distal radius (23-A2, 23-A3) a proximal basic wire is inserted through both bones of the forearm: V,6-12(V,612). The ring support is located perpendicular to the anatomical axis of the proximal fragment of the radial bone and oriented relative to the soft tissues so that the forearm at level V is in the centre of the ring support. Wire V,6-12(V,6-12) is tensioned and fixed to it.

2

3

5

4

V,6-12(V,6-12); VI,4-10 —— VIII,11-5; VIII,6-12(VIII,6-12) 120

120

1

—— m/carpV – m/carpII 1/2 120

Fig. 2.3.21. External fixation device for fixation of fracture 23-A1.2

An intermediate support is installed at level VIII of the forearm and connected by three rods to the basic ring. In Colles’ fractures (23-A2.2), the support fixed to the hand is installed so that it is located parallel to the proximal basic and intermediate supports but is displaced dorsally so that the hand is in palmar ﬂexion at 25–30◦. In Smith’s fractures (23-A2.3), the hand is placed in dorsiﬂexion at 25–30◦ . After mounting the external supports of the device a distraction force is applied. On the basis of comparison radiographs,reductionally fixing wires are inserted through the fragments of the radius.In Colles’fractures these are usually wires (VI,2-8) and (VIII,7-1), and in Smith’s fractures they are (VI,8-2) and (VIII,1-7). The wire at level VIII must be strictly perpendicular to the anatomical axis of the distal fragment of the radius. Using stops, the wires are bent in an arc and the fracture is finally reduced. Then the diastasis between the fragments is eliminated.

2.3 Fractures of the Forearm

2

3

4

5

V,6-12(V,6-12); (VI,9,90) —— (VIII,1-7); (VIII,11,110) 120

120

1

—— m/carpV – m/carpII 1/2 120

2

157

3

V,6-12(V,6-12); (VI,10,90) —— 120

5

6

4

VII,11,110; VIII,6-12(VIII,6-12); (VIII,1-7) 120

1

Fig. 2.3.22. External fixation device for fixation of fracture 23-A2.2

In oblique or splintered fractures, a wire is inserted through both bones of the forearm: VIII,6-12(VIII,612). If the fracture line allows axial compression, and the relationships in the distal radioulnar joint are not interrupted, a half-pin or a 2-mm wire (VIII,11,110) is inserted. Figure 2.3.22 shows a hybrid external fixation variant for the injury 23-A2.2. In transverse fractures the operation is completed by removal of the support from the hand. In splintered fractures this is done in 2–2.5 weeks. External fixation of intraarticular fractures of the distal part of the forearm bones (23-B, 23-C) is carried out similarly. Intermediate supports should not be located in the joint space plane as they will hinder radiographic evaluation. An alternative solution is to use an X-ray transparent. After distraction, whether congruence of the articular surfaces has been restored by ligamentotaxis is determined radiographically. The position of the bone fragments can be improved using wires with stops and

—— m/carpV – m/carpII 1/2 120

Fig. 2.3.23. External fixation device for fixation of fracture 23-C3.3

posts with a stop.If closed reduction fails,reduction can be achieved with an external fixation device with the minimum surgical approach only controlling the position of the bone splinters. Osteoautoplasty can also be used if indicated. Figure 2.3.23 shows a CEF variant for fracture 23C3.3. With this type of fractures the distal support is dismantled in 2–4 weeks. In fragmented, splintered, open infected fractures the transosseous elements through the distal part of the forearm bones are not used. When full-volume external fixation is impossible, for example in the event of mass admission of casualties, and if the patient’s condition is grave the fracture can be immobilized using a device with two supports. The same external fixation variant can be used when it is impossible at that moment to perform the necessary open reduction of the bone fragments.

158

2 Specific Aspects of External Fixation

Wire V,6-12(V,6-12) is tensioned and fixed to the ring support. The second wire is inserted through the metacarpal bones: m/carpV–m/carpII. This wire is fixed after tensioning to a half-ring or a two-thirds ring. A moderate distraction force is applied between the supports: V,6-12(V,6-12) ↔ m/carpV–m/carpII. Later the device can be converted to a full assembly. After comparison radiographs have been obtained, the arm is fixed with a cravat bandage with the elbow ﬂexed at 90–100◦ . If the support was assembled on the hand, two rods are connected to the device, with a gauze sling stretched between them for temporary immobilization of the bone in the mid-physiological position.

2.4

Fractures of the Femur

In femoral osteosynthesis (Figs. 2.4.1–2.4.19), wires of diameter 1.8–2 mm are used. In CEF half-pins of diameter 5 and 6 mm are used in addition to the wires. The external fixation set must also include 2-mm console wires with a stop with various lengths of the part inserted in the bone (5, 10, 15 and 20 mm). In Ilizarov external fixation of the femur, at levels 0, I and II one-third or one-quarter sector or radius bar external supports are used. The half-pins used in CEF in the proximal part of the femur are fixed to the sector or radius bar supports. The supports are onethird or one-quarter rings. At levels III and IV of the femur, two-thirds or three-quarter rings are used. They are mounted with the open part inwards so that the patient can adduct the limb. In external fixation of the femur, the external supports at the first six levels (levels 0 to V) must be two or three standard sizes larger than the supports in the distal third of the femur. Therefore, the modules forming the proximal and distal bone fragments are connected by connection plates. The supports located at the distal three levels of the femur (levels VII, VIII and IX) are two-thirds or threequarter rings to allow ﬂexion of the knee. In external fixation of juxtaarticular and intraarticular fractures (33- according to the AO/ASIF classification) the use of radiotransparent external supports is recommended. To prevent knee stiffness, the transosseous elements at the four distal levels of the femur (from VI to IX) are inserted through the soft tissue of the anterior semicircle of the femur with the lower leg bent to an angle of 90–120◦ . Transosseous elements through the posterior semicircle of the femur are inserted with the lower leg extended.When it is impossible to achieve the necessary angles, the skin is displaced manually or with a thin hook in the direction of its natural move-

ment relative to the bone with movement in the adjacent joint. When using only reference positions to insert transosseous elements, it is not necessary to change the position in the joint. However, the technique of preliminary (prior to insertion of transosseous elements) displacement of the skin must be applied in lengthening of the segment, correction of deformities, bilocal osteosynthesis and other situations when it is necessary to create a stock of soft tissue. Before fixation of transosseous elements the external support must be appropriately oriented relative to the anatomical axis of the bone fragment and the soft tissue. In external fixation the external supports must be perpendicular to the anatomical (mid-diaphyseal) axis of the bone fragment to which they are fixed. As the distal epidiaphyseal angle of the femur is about 81◦ (Fig. 2.8.2), the supports on the femur should not be placed parallel to the knee joint space. Exceptions are osteosynthesis of intraarticular fractures of the distal part of the femur and situations when the supports are intentionally placed in a position of hypercorrection described below. If the device assembly includes a reductionally fixing support between level III and levelV of the proximal fragment of the femur, it is located as follows. The distance between the inner edge of the ring (notionally extrapolated in the case of an open support) and the lateral aspects of the femur must be the same. The distance from the skin to the support at the back must be 2.5–4 cm more than at the front. To connect this ring by rods to the proximal basic support, due to the different diameters of the supports, connection plates are additionally used. When the device assembly requires the use of two external supports of different diameters (distal reductionally fixing and distal basic supports) for the distal bone fragment,they are preliminarily connected by one rod along the anterior surface. In this case the distal basic support appears to be displaced forwards relative to the reductionally fixing support. At this stage the supports are not fixed to the transosseous elements. The rod connecting the supports is installed parallel to the anatomical axis of the distal bone fragment. The distal reductionally fixing support is then oriented relative to the soft tissues so that the distance from the skin to the support at the back is 2.5–4 cm more than at the front, while the distances from the inner edge of the ring and the lateral aspects of the femur are the same. Then using axial rotation on the connection rod of the distal basic support it is oriented relative to the soft tissues. Only then are the transosseous elements inserted at the level of the distal basic support fixed. Finally the remaining two or three connection rods are mounted using connection plates (Fig. 2.4.2).

2.4 Fractures of the Femur

a

159

b

Fig. 2.4.1a,b. Orientation of the proximal basic supports in Ilizarov external fixation of the femur. The proximal (basic) support is oriented relative to the soft tissue so that the distance between the internal edge of the support and the skin in the front and laterally is in the range 3–4 cm. The distance from the skin to the support along the posterior aspect is in the range 3–4 cm more (a). When half-rings are used, the distance between the surface of the skin and the support along the anterior external surfaces of the femur is constant (3–4 cm). Also the size of the support is such that its internal edge corresponds to the plane of position 1 and the posterior external edge– to the plane of position 8 (b)

Fig. 2.4.2. Installation of distal reductionally fixing and basic supports on the femur

The ends of the wires and half-pins that are at some distance from the support after it has been given the necessary spatial orientation are fixed using posts and/or spacer washers. The half-pins, unless they are basic or reductionally fixing transosseous elements,are stabilized in the external supports only after the necessary spatial orientation of the bone fragments has been achieved. If a half-pin is inserted in the bone not parallel to the external support, it is fixed to the support using two posts, one female and the other male. The half-pin can be fixed to the support or post using an L-shaped clip, similar to the use of a laterally slotted wire clamp. The next sections which describe particular external fixation methods contain the phrase: “When the device modules are properly installed, the connection rods are parallel to the anatomical axis of the bone fragment.”However, it should be taken into account that the position of a basic support fixed on wire(s) only is likely to change due bending of the wires from the weight of the wires and connection rods. In such cases, to control its orientation, the external fixation module should be supported by hand thus neutralizing the bending ﬂexure of the wires.

Reduction by wires is achieved by displacement of the bone fragment with the help of a stop and bending of the wire (Fig.1.6.9).Reduction with half-pins is more often achieved by “pushing” or “pulling”, and with console wires with a stop only by “pushing” (Fig. 1.6.10). It is also possible to use any reduction technique together with mutual displacement of the external supports (Figs. 1.6.4–1.6.8). Large splinters are reduced and fixed using wires with stops or console wires with stops (Fig. 1.6.13). When there are great vessels and nerves in the plane of the splinter, its reduction and fixation are performed using a fork device (Figs. 1.4.8 and 1.6.14). It should be born in mind that in all the external fixation diagrams, the direction of insertion of reduction transosseous elements (wires, half-pins) and the locations of the stops on the wires are given as examples. In practice one should be guided by the actual residual displacement of the bone fragments. To avoid injury to great vessels and nerves safe positions at the levels recommended for insertion of reductionally fixing transosseous elements identified in the atlas are used. The sizes of the external supports in the diagrams are also examples only.

160

2 Specific Aspects of External Fixation

For external fixation of the femur, regional anaesthesia is generally used.Transportation immobilization is removed on the operating table after induction of anaesthesia. External fixation of the femur requires rough preliminary elimination of displacement of the bone fragments by skeletal traction. The patient is laid on the orthopaedic traction table with a pelvic stand and a perineal radiotransparent rest.Wire VIII,3-9 is inserted through the condyles of the femur and tensioned in the half-ring of the traction unit of the orthopaedic traction table. In low fractures wire I,3-9 for skeletal traction is inserted through the proximal metaphysis of the tibia. In CEF,skeletal traction on the orthopaedic traction table is performed by a wire that will be further used in the device as the distal basic wire: VIII,3-9 or VII,3-9 or VI,3-9 depending on the device assembly. The size of the fixture (half-ring) for skeletal traction must be sufficient for placement of the distal basic support of the device inside it. The positions of the bone fragments are improved by axial traction and manual manipulation.To facilitate reduction, the injured segment is overtensioned by up to 5–8 mm, monitoring distraction in the attachment by comparison with the other femur. X-ray contrast markers are placed on the skin (injection needles, wire fragments) and comparison radiographs are obtained in two standard planes or an image intensifier is used. Lines are drawn on the skin of the anterior and external aspect of the femur corresponding to the plane of the anatomical axis of each bone fragment. Using the special device shown in Fig. 1.8.2, the levels for insertion of the transosseous elements are marked. With accumulating clinical experience of external fixation of diaphyseal fractures,the need for comparison radiographs during skeletal traction is reduced. The operative site is treated and draped. An invariable rule for external fixation of closed fractures is radiographic confirmation of the precise reduction on the operating table. First, the principal large splinters are reduced and fixed with Kirschner wires with stops, or with periosteally inserted wires or console wires with stops. The practice of hastily assembling an external fixation device and performing the reduction after transfer of the patient to a clinical department with daily stepwise radiographic monitoring of the manipulations performed is an unsatisfactory and discredited method of external fixation. An exception to this rule is when a fixation device is applied as described below. After external fixation it is necessary to check the passive movements in of the joints adjacent to the segment operated upon. Tension in the soft tissues as a result of insertion of the transosseous elements must be elimi-

nated by releasing the skin and, if required, the fascia and muscles. After Ilizarov external fixation, a special trolley for transportation of the patient with an opening for the device and a bed with a similar opening (Fig. 2.17.1) are required. Patients must be warned that during fixation they will not be able to use a normal bed and/or sit. After external fixation with a hybrid or pin device a normal trolley and bed can be used.

2.4.1

Proximal Femur (31-)

Specific features of insertion of transosseous elements in external fixation of proximal femur fractures presuppose the possibility of axial compression of bone fragments only. Therefore, special attention should be paid to the precision of the preliminary reduction. For convenience of the operation, it is necessary to use an image intensifier. In femoral neck fractures (31-B2) closed reduction of bone fragments is performed by one of the known methods. The leg is then slightly abducted (20–30◦ ), rotated maximally inward (up to 45–60◦) and fixed in this position in the attachment of the orthopaedic traction table. The uninjured leg is ﬂexed at an angle of 90◦ at the hip and knee and is placed on the attachment to the orthopaedic traction table so that it will not hinder radiography in the axial plane. If counter-extension by the unaffected leg is necessary, it is lowered above or below the injured limb. In pertrochanteric fractures of the femur (31-A1, 31-A2) the femur is abducted on the orthopaedic traction table to an angle of 15–20◦ and ﬂexed at an angle of 15–25◦ . In elderly debilitated patients reduction is performed without the hip abduction and ﬂexion. In intertrochanteric fractures (31-A3) it is necessary to abduct and ﬂex the hip by the amount of displacement of the proximal fragment, usually up to 30–40◦ . In undisplaced fractures only “disciplinary” traction is applied on the orthopaedic traction table without abduction of the limb. In the plane of the inguinal ligament, a connection plate from the Ilizarov set is placed and fixed to the skin, further serving as a landmark. To mark the neck of the femur an injection needle is inserted at the upper and lower boundaries. Comparison radiographs are obtained in two planes or an image intensifier is used. If reduction is confirmed, external fixation is started. Ilizarov external fixation of fractures of the femoral neck (31-B2) starts with insertion of a wire in the subtrochanteric region 8–9 cm from the top of the greater trochanter, along the lateral external surface of the femur in the direction of the upper pole of the femoral head. A second wire is inserted in the same plane 4.5–

2.4 Fractures of the Femur

161

Fig. 2.4.3. Skeletal traction in diaphyseal fractures of the femur. The uninjured limb is fixed in the foot-support of the orthopaedic traction table and the necessary traction force is applied to prevent pelvic warping. The panels of the table located under the pelvis and femur are lowered. The specific features of the external fixation of the various parts of the femur are described in the respective sections

5 cm from the top of the greater trochanter in the direction of the lower pole of the head. Thus, these two wires form a cross in a plane close to the frontal plane [7]. A wire is then inserted from the anteroexternal surface of the femur at a distance of 5.5–6.5 cm from the top of the trochanter in the direction of the posterior surface of the femoral head. A fourth wire is inserted at the same level from the posteroexternal surface in the direction of the anterior surface of the femoral head. A third and fourth wire form a cross at 45–65◦ in the sagittal plane. A mandatory condition is the subchondral location of the guiding ends of all four wires, which is monitored radiographically. The device configuration for tension of the diafixation wires depends on the length of the splinter levers, and the degree of development of the muscle tissue depends on the number of external supports. With a relatively short femur with small thickness of soft tissues allow a ring of diameter 180–195 mm to be used with wires IV,1-7; V,1-7; V,2-8; VI,3-9 (Fig. 2.4.4a). Figure 2.4.4b shows the configuration of the device on the basis of two external supports: IV,1-7; IV,6-12– VI,2-8; VI,3-9. The diafixation wires are fixed to a threaded bar to provide the possibility of separate repositioning along it to tension each pair of wires. The wires can also be fixed using a monolateral support and half-pins: III,9,90; IV,9,90. When using a half-pin-based device for external fixation after reduction, two or three 6-mm half-pins with a spongy thread are inserted parallel in the femoral neck. For insertion of the half-pin at level I, it is enough to make a canal with an awl in the adjacent cortical plate. Starting from level II and distally, where there is a more marked cortical plate,a canal is made with a borer for insertion of the half-pins. Nonobservance of this rule may result in splintering of the bone, which will considerably complicate external fixation and make

a

b

Fig. 2.4.4a,b. Ilizarov external fixation device for fixation of fracture 31-B2.1

the prognosis worse. To ensure later interfragmentary compression the spongy thread should be located more medial than the fracture zone. All half-pins should be inserted as far as the subchondral layer of the femoral head. Two or three 6-mm half-pins can also be used as basic transosseous elements. The less stable the fracture, the heavier the patient and the greater the need for early loads are indications to increase the number of fixation and basic half-pins. Figure 2.4.5a shows a variant of external fixation of fracture 31-A1.3 using a monolateral device with halfpins III,9,90 and IV,9,90 as the basic pins. figure 2.4.5b shows a variant of the external fixation of fracture 31A2.3 using a sectorial device with three basic half-pins: IV,9,90 – V,8,90; VI,8,70. The half-pins inserted in the femoral neck can be fixed both in the monolateral (as in the figure) and in the sectorial support. After comparison radiographs have been obtained, the skeletal traction is dismantled and the patient is transported to the ward. During transportation there

162

a

2 Specific Aspects of External Fixation

b

Fig. 2.4.5a,b. Ilizarov external fixation device for fixation of trochanteric fractures (31-A)

must be a soft cushion under the knee to ensure ﬂexion of 60–45◦ .

1

2

6

8

5

7

I,6-12; I,11-5; II,11-5; II,6-12 —— arc 250

2.4.2

Diaphyseal Fractures (32-)

In skeletal traction, the distal fragment is placed in the mid-position between external and internal rotation. The rotational displacement of the proximal fragment is eliminated after fixation of both bone fragments by the modules of the device. For that purpose, the transosseous module fixing the proximal bone fragment is held manually and placed in the position of maximum external rotation. It is then rotated maximally inwards. Then it is again rotated outwards by 30–40◦ to place it in the neutral position. In this position, the proximal and distal transosseous modules are connected by modules. If the mobility of the hips is limited by the presence of pathology, it is necessary to determine the amplitude of rotational movements in the intact limb in the preoperative period. 2.4.2.1 Proximal Third In fractures of the proximal third of the femoral diaphysis (injuries 32-A1.1, 32-A2.1, 32-A3.1, 32-B1.1, 32B2.1, 32-B3.1, 32-C according to the AO/ASIF classification) skeletal traction is applied on the orthopaedic traction table with the hip abducted at 30–45◦ . The more proximal the fracture, the greater the abduction angle. In subtrochanteric fractures, the hip must be additionally ﬂexed to 40–50◦ . The Ilizarov operation starts with insertion of crossing proximal basic wires through the proximal metaphysis of the femur. Before insertion of the first wire, pulsation of the femoral artery is first detected by palpation in Scarpa’s triangle, and the wire is then

3

4

V,8-2; V,1-7 —— VII,2-8; VII,4-10 195

180

Fig. 2.4.6. Ilizarov external fixation device for fixation of fracture 32-A1.1

inserted 15–20 mm from the artery towards the outside. The second wire is inserted at an angle of 30◦ to the first [8]. In Fig. 2.4.6, these wires are designated as I,6-12 and I,11-5. In some cases it is technically complicated to insert the wire with a stop I,6-12. If this is the case, the wire I,12-6 is inserted and embedded in the soft tissue until its tail protrudes 30–40 mm. A ﬂexural rest (corrugated or spit-like) is then formed on the opposite side at the clunis. By pushing the end, the rest of the wire is inserted as far as the bone, and thus wire I,12-6 becomes I,6-12. It should be emphasized that a wire with such a ﬂexural rest must not be tensioned with a force of more than 400 N. Therefore, to ensure sufficient rigidity of the external fixation, it is necessary to insert an additional wire or to insert console wire I,9,90, as the Russian Ilizarov Research Center recommends. In the supracondylar region the distal basic wires VII,2-8 and VII,4-10 are then inserted perpendicular to the anatomical axis of the distal fragment. For the proximal support the femoral sectorial support is oriented relative to the anatomical axis of the proximal bone fragment, relative to the soft tissues, and the wires are fixed to it after tensioning. If the length

2.4 Fractures of the Femur

a

b 2

3

6

5

4

7

1

I,8,90; I,11,90; II,9,70; III,10,80 —— V,8-2; VI,9,70 —— VII,3-9 (a) 1/3 225 3/4 195 3/4 180 I,8,90; I,11,90; II,9,70 —— V,8-2; VI,9,70 1/3 225

(b)

3/4 195

a

b 2

3

5

4

1

6

I,8,90; I,11,90; II,9,70 —— IV,9,90 —— VI,3-9; VII,8,70 (a) 1/3 225 3/4 195 180 I,8,90; I,11,90; II,9,70 —— IV,9,90 —— VII,8,70 1/3 225

1/3 195

1/3 180

(b)

163

Fig. 2.4.7a,b. CEF device for fixation of fracture 32-B1.1. The wire for skeletal traction is used as the distal basic support. It is important that the proximal basic support is perpendicular to the proximal bone fragment (a). Fixation of half-pin VI,8,70 to the reductionally fixing support allows the distal basic support VII,3-9 to be removed in 7– 8 weeks (b). Additional information is provided in section 2.17

Fig. 2.4.8a,b. Variant CEF device for fixation of fractures of the proximal third of the femur (32-C1.3). This variant is useful for patients with a relatively short femur and thick soft tissues. To reposition the distal fragment halfpin V,8,90 or IV,9,90 or IV,10,90 (not shown) is pushed or pulled. With such assemblies stepwise transition from a wire-pin semicircular device with a three-quarter ring (a) to a pin device one-third rings (b) is possible

164

2 Specific Aspects of External Fixation

of the proximal bone fragment exceeds 110–120 mm, an additional (reductionally fixing) sectorial support is installed connected by three rods to the proximal basic support. The reductionally fixing support is then installed for the distal fragment at level V of the femur. It is connected by three rods to the distal basic ring. The reductionally fixing support is oriented relative to the bone and soft tissues.The wiresVII,2-8 andVII,4-10 are then tensioned and fixed to the distal support, either directly to the ring or, if offset, using posts. When the distal module of the device is properly installed, its connection rods are parallel to the anatomical axis of the distal bone fragment. The rotational displacement of the proximal fragment is eliminated and then the proximal basic support is connected by three rods to the reductionally fixing support. A distraction force is applied to create an interfragmentary diastasis of 5–7 mm if this was impossible to do on skeletal traction. Radiographs are obtained in two standard planes or an image intensifier is used. To eliminate residual displacement of the proximal bone fragment at level II (or III) a reductionally fixing wire is inserted. To eliminate residual displacement of the distal fragment at level V a second wire is inserted. The direction of insertion of these wires and the location of their stops depend on the residual displacement of the bone fragments. To avoid injury to the great vessels and nerves only safe positions as identified in the atlas for levels II and V of the femur are used. Figure 2.4.6 shows, as an example, the wires II,11-5 and V,8-2.

Ilizarov external fixation starts with insertion of pairs of proximal and distal basic wires: I,6-12; I,11-5 and VII,2-8; VII,4-10. The specific features of insertion of the wires are noted above in the description of the fixation of femoral fractures of the proximal third of the diaphysis. The femoral sectorial support is placed perpendicular to the axis of the proximal bone fragment and oriented relative to the soft tissues. After that the proximal basic wires are tensioned and fixed to the support. At level III or level IV (depending on the fracture location) the proximal reductionally fixing support is installed. This is a two-thirds or three-quarter arc or sectorial support and it is oriented relative to the bone and soft tissues. The proximal basic and reductionally fixing supports are then connected by three or four rods. When properly oriented, the connection rods are parallel to the anatomical axis of the proximal bone fragment. At level V or level VI, a distal reductionally fixing support (a ring of the appropriate size) is installed. It is connected by rods to the distal basic ring. The distal reductionally fixing support is oriented relative to the bone and soft tissues. It is important to note that, as the distal epidiaphyseal angle in the frontal plane is on av-

2.4.2.2 Middle Third By known techniques (repositioning the bone fragment using a stop together with bending of the wire) the proximal and then the distal bone fragments are successively reduced. It is also possible to use any reduction technique together with mutual displacement of the external supports (Figs. 1.6.4–1.6.8). For unstable splintered fractures in muscular and/or overweight patients, additional transosseous elements, for example II,6-12 or V,1-7, can be inserted to increase the rigidity of the external fixation. In fractures of the middle third of the diaphysis of the femur (injuries 32-A1.2, 32-A2.2, 32-A3.1, 32-B1.2, 32-B2.2,32-B3.2,32-C1,32-C3 according to the AO/ASIF classification) skeletal traction on the orthopaedic traction table is applied with the hip abducted 15–30◦ . The more proximal the fracture location, the greater the abduction must be. In fractures at the boundary of the middle and lower thirds of the diaphysis, traction is performed without hip abduction.

1

2

5

7

I,1-7; I,6-12 —— III,1-7; III,6-12 —— arc 250

6

arc 250

8

3

4

V,2-8; V,1-7 —— VII,2-8; VII,4-10 180

180

Fig. 2.4.9. Ilizarov external fixation device for fixation of fracture 32-C3.2

2.4 Fractures of the Femur

165

Fig. 2.4.10a,b. Functional CEF device for fixation of diaphyseal fractures of the femur. The wire for skeletal traction on the orthopaedic traction table is used as the distal basic wire VIII,3-9. To eliminate residual displacement of the proximal bone fragment at level III or level IV (depending on the fracture level), a half-pin is inserted perpendicular to the anatomical axis of the fragment in position 8, 9 or 10. The position chosen depends on the direction of displacement of the bone fragment such that the half-pin is mostly “pushed” or “pulled”. To eliminate residual displacement of the distal fragment wire VI,3-9 or VI,9-3 is used or, as shown in a, half-pin VI,9,90. The use of the Barabash cube (Figs. 1.2.2k and 1.4.10) will make the reduction easier. Transfer of the half pin II,11,90 allows the proximal basic support (b) to be removed in 6–8 weeks. Additional information is provided in section 2.17

a

b 2

3

6

4

5

7

1

I,8,90; II,11,90 —— III,9,120; IV,10,90 —— VI,9,90 —— VIII,8,70; VIII,3-9 (a) 1/3 225 3/4 195 180 3/4 180 II,11,90; III,9,120; IV,10,90 —— VI,9,90 —— VIII,8,70 1/3 195

1/3 180

1/3 180

erage 81◦ (Fig. 2.8.2), the distal supports are not placed parallel to the knee joint space but rather at an angle of 7–11◦ to it. Only then are the wires VII,8-2 and VII,10-4 tensioned and fixed to the distal basic support. When the distal module of the device is properly installed, its connection rods are parallel to the anatomical axis of the distal bone fragment. The rotational displacement of the proximal fragment is eliminated and the proximal basic support is then connected by rods to the reductionally fixing support. A distraction force is applied to create an interfragmentary diastasis of 5–7 mm if this was impossible by skeletal traction. Radiographs are obtained in two standard planes or an image intensifier is used. To eliminate residual displacement of the proximal bone fragment at level III or level IV, a reduction wire is inserted. To eliminate residual displacement of the distal fragment at level V (or level IV) a second reduction wire is inserted. Figure 2.4.9 shows, as an example, the wires III,1-7 and V,2-8. Using known techniques (repositioning by bending of the wire with a stop), the proximal and then the distal bone fragments are successively reduced. It is also possible to use any reduction technique together with mutual displacement of the external supports. For fragmented fractures in muscular and/or overweight

(b)

patients, an additional wire can be inserted to increase the rigidity of the external fixation at the level of reductionally fixing supports. 2.4.2.3 Distal Third In fractures of the distal third of the femoral diaphysis (injuries 32-A1.3,32-A2.3,32-A3.3,32-B1.3,32-B2.3,32B3.3, 32-C1, 32-C3 according to the AO/ASIF classification) skeletal traction on the orthopaedic traction table is applied without abduction of the segment. To avoid backward tilting of the distal fragment, the knee must be ﬂexed in skeletal traction at an angle of no less than 60–90◦. Ilizarov external fixation starts with insertion of two proximal basic wires: III,6-12 and III,1-7. The distal basic wires VIII,2-8 and VIII,4-10 are then inserted. The proximal basic ring is oriented relative to the bone and soft tissues and wires III,6-12 and III,1-7 are fixed to it after tensioning. Instead of a ring, it is possible to use a femoral sectorial support comprising a twothirds or three-quarter ring.A reductionally fixing ring is then installed at level V, oriented relative to the soft tissues and connected by three rods to the proximal basic support. When properly installed, the connection rods are parallel to the axis of the proximal bone fragment.

166

2 Specific Aspects of External Fixation

1

2

5

7

6

3

4

III,6-12; III,1-7 —— V,2-8; VI,9,90 —— VII,9-3; VIII,2-8; VIII,4-10 195

195

180

Fig. 2.4.11. Ilizarov external fixation device for fixation of fracture 32-B2.3

a

b 2

6

3

5

4

7

1

II,9,90 —— IV,10,120; V,2-8; VI,7,100 —— VII,9-3; VIII,8,90; VIII,3-9 (a) 1/3 225 195 3/4 180 IV,10,120; V,2-8 —— VII,9-3; VIII,8,90; VIII,3-9 195

3/4 180

(b)

Fig. 2.4.12a,b. CEF device for fixation of fracture 32-B3.3. The distal basic support is fixed to the wire for skeletal traction VIII,3-9 such that it is perpendicular to the anatomical axis of the distal fragment. If the radiograph in skeletal traction shows that the backward tilt of the distal fragment has not been fully eliminated, the distal support is installed in hypercorrection of 7–◦ 10◦ . An additional wire VIII,8-2 is inserted and fixed in it after tensioning. After final reduction of the principal bone fragments and large splinters, half-pins IV,8,120 and VIII,8,90 are inserted and fixed to the supports to increase rigidity. Wire VIII,8-2 is removed (a). In 6–8 weeks the proximal support can be removed (b)

2.4 Fractures of the Femur

a

b 2

3

6

4

5

1

I,8,90; II,11,90 —— V,9,90 →← VII,4,120; VIII,8,90; VIII,3-9 (a) 1/3 225 195 3/4 180 I,8,90; II,11,90 —— V,9,90 →← VII,4,90; VIII,8,90 1/3 225

1/3 195

3/4 180

(b)

167

Fig.2.4.13a,b. CEF device for fixation of fracture 32-A3.3. In patients with overdeveloped muscles and/or who are overweight, the proximal basic support is based on two half-pins: I,8,90 and II,11,90. For final reduction of the proximal bone fragment, it is possible to use half-pin V,8,90 or V,9,90. If radiographs obtained during skeletal traction reveal proper location of the distal fragment, the distal basic support is assembled based on a wire and two half-pins: VII,4,120; VIII,8,90; and VIII,3-9 (a). The internal part of the reductionally fixing support and wire VIII,3-9 can be removed after 6–8 weeks (b)

Fig. 2.4.14a,b. CEF device for fixation of segmental fracture 32-C2.2. Half-pin a b IV,8,90 and wire V,8-2 are used to reduce and fix the intermediate fragment (a). 2 3 4 6 7 5 8 1 I,8,120; II,11,90; III,9,70 →← IV,9,90; V,8-2 —— VI,3-9; VII,8,120 —— VIII,3-9 (a) The distal basic support can be removed 1/3 225 195 180 3/4 180 after 10–12 weeks. This results in “dynamization” of the device and a reduc→← — — IV,9,90; V,8-2 VI,3-9; VII,8,120 I,8,120; II,11,90; III,9,70 (b) tion in its size (b) 1/3 225 195 3/4 180

168

2 Specific Aspects of External Fixation

Fig. 2.4.15. Device for temporary fixation of femoral fragments [9]

If the comparison radiographs show that the backward tilt of the distal fragment has not been fully eliminated, the distal support is installed with 7–10◦ of hypercorrection. Furthermore, in relation to the frontal projection, the ring must be located at an angle open inwards of about 9◦ relative to the knee joint space. This is because the epidiaphyseal angle in the frontal plane is 79–83◦ (Fig.2.8.2).In this position wires VIII,28 and VIII,4-10 are tensioned and fixed to the support. If the length of the distal bone fragment exceeds 110– 120 mm, a second reductionally fixing ring should be installed connected to the distal basic support by three rods. After mounting the proximal and distal modules of the device, the rotational displacement of the proximal fragment is eliminated and the modules are connected by three or four rods. A distraction force is applied to create an interfragmentary diastasis of 5 mm if this was impossible by skeletal traction. Radiographs are obtained in two standard planes or an image intensifier is used. To eliminate residual displacement of the proximal bone fragment the wire V,2-8 (or V,8-2) is inserted and fixed to the reductionally fixing ring after tensioning. To eliminate residual displacement of the distal fragment the wire VII,3-9 or VII,9-3 is used (Fig. 2.4.11). For fragmented fractures in muscular and/or overweight patients, additional transosseous elements, for example V,1-7 and VII,2-8, can be inserted to increase the rigidity of the external fixation.

The modular transformation of the devices shown in the Figs. 2.4.7b, 2.4.8b, 2.4.10b, 2.4.12b and 2.4.14b is described in section 2.17. When full-volume external fixation of diaphyseal femoral fractures is impossible,for example in the event of mass admission of casualties, the so-called“fixation” variant of external fixation can be performed.Two halfpins are inserted in the proximal metaphysis of the femur and fixed to a one-third sectorial support. Two crossing wires are inserted through the distal metaphysis of the femur and tensioned in a three-quarter ring support. Moderate distraction is applied between the supports: I,8,90; II,11,90 ↔ VII,3-9; VII,2-8. In fractures of the distal third of the femur the distal support is placed at level VIII: I,8,90; II,11,90 ↔ VIII,3-9; VIII,2-8. Figure 2.4.15 shows another variant for temporary fixation of femoral fragments. Two half-pins are inserted in each bone fragment in the frontal plane (or in a plane close to the frontal plane). After rough elimination of displacement of the fragments all halfpins are fixed to a long plate, for example I,9,90; III,10,120; V,9,90; VII,8,90. The “fixation” variant of external fixation undoubtedly has advantages over skeletal traction: less bulkiness, higher mobility of the patient, possibility of reduction using both skeletal traction and reductionally fixing transosseous elements during assembly of the device. After comparison radiographs have been obtained, the skeletal traction is removed and the patient is taken to the ward. During transportation a soft cushion must be placed under the knee to ensure ﬂexion of 45–60◦ .

2.4.3

Distal Femur (33-)

In fractures of the distal part of the femur, skeletal traction on the orthopaedic table is applied only in cases of extraarticular injuries (33-A). For that purpose a wire inserted through the proximal metaphysis of the tibia is used: I,3-9. The knee must be ﬂexed at 60–70◦ . In intraarticular fractures (33-B, 33-C) for convenience of application of the basic device supports,“disciplinary” traction at the foot is applied or the lower leg is placed on cushions. If indicated, the knee joint is punctured for the aspiration of blood and effusion ﬂuid. In extraarticular fractures (33-A1.2, 33-A1.3,33-A2, 33-A3 according to the AO/ASIF classification) as well as in slipped epiphyses and osteoepiphyses, the device assembly is similar to that used in fractures of the distal third of femoral diaphysis (Fig. 2.4.11). Ilizarov external fixation starts with installation of the basic support on the femur: IV,6-12; IV,1-7. A reductionally fixing ring is installed at level VI and fixed

2.4 Fractures of the Femur

by three rods to the proximal basic support. When the device is properly mounted, the connection rods are located parallel to the anatomical axis of the femur. Two crossing wires VIII,2-8 and VIII,4-10 are then inserted through the distal fragment perpendicular to its anatomical axis. If comparison radiographs obtained during skeletal traction show that the backward tilt of the distal fragment has not been eliminated, the ring is installed with 7–10◦ of hypercorrection. The wires are then tensioned and fixed to it. The distal and reductionally fixing rings are then connected by three rods and a distraction force is applied to create an interfragmentary diastasis of 4–5 mm if this was impossible by skeletal traction. Radiographs are obtained in two standard planes or an image intensifier is used. To eliminate residual displacement of the proximal fragment at the level of the reductionally fixing support, a wire with a stop is inserted: VI,3-9 or VI,9-3. If the distal fragment is small a wire cannot be used for its final reduction. To increase the rigidity of the external fixation wire VIII,3-9 can be inserted. Any residual displacement is eliminated by displacement of the distal support relative to the transosseous module fixing the proximal fragment (Figs. 1.6.4–1.6.8). If the ligaments of the knee are injured, in the presence of marked oedema of the soft tissues and haemosynovitis, or if the knee requires fixation for other reasons, the support II,2-8; II,4-10 is applied to the lower leg. Alternatively, a hybrid wire-pin support II,9-3; III,1,120 connected by hinges to the basic device can be used. After insertion of the half-pin V,8,120 and its fixation to the support the proximal support can be dismantled. Ilizarov external fixation of isolated fractures of the femoral condyle (injuries 33-B according to the AO/ASIF classification) starts with insertion of two crossing wires in the lower third of the femur. After tensioning the wires are fixed to the ring support: VI,3-9; VI,2-8. The support must be located perpendicular to the biomechanical axis of the limb, i.e. at an angle of about 10◦ to the anatomical axis of the femur (Fig. 2.8.2). If the condyle is considerably displaced, the basic support should be installed with 7–10◦ of hypercorrection rather than perpendicular to the anatomical axis of the femur, by inclining the ring towards the injury. The second ring, preferably made of a radiotransparent material, is installed at the level of the femoral condyles and connected by three rods to the basic support. Crossing wires are then inserted through the proximal metaphysis of the tibia. After tensioning, they are fixed to the ring support II,2-8; II,4-10. The support is preferably installed at an angle of 7–10◦ to the fracture, rather than perpendicular to the anatomical axis of the

169

tibia. The distal basic support of the femur is connected to the lower leg support by three or four hinges. After mounting of the device a distraction force is applied mostly on the injured side between the distal support of the femur and the support applied to the lower leg. Preliminary placement of the basic supports in positions of hypercorrection facilitates the parallel positioning of all ring supports after distraction. Radiographs are obtained or an image intensifier is used. If no reduction is achieved by ligamentotaxis and additional bringing down of the condyle is required, a wire with a stop is inserted through it in a plane close to the sagittal plane. The location of the stop depends on whether the condyle is to be displaced forwards or backwards. The wire is tensioned in the support installed at level VIII of the femur. A distraction force, uniform at all the pins, is then applied between two proximal supports of the device (Fig. 2.4.16a). If comparison radiographs confirm that the condyle has been brought down by the necessary amount, a wire with a stop is inserted in the frontal plane: VIII,3-9 in fractures of the internal condyle or VIII,9-3 in fractures of the external condyle. Then, at a distance of 15–20 mm from the exit point of this wire, a wire is inserted in the opposite direction. If osteoporosis is present wires with curved spiral stops are recommended. The wire inserted in the sagittal plane is removed. Additional rigidity of the external fixation is provided by insertion of an additional wire through the injured condyle. After that, unless there are special indications for knee joint fixation, the support can be removed from the lower leg (Fig. 2.4.16b). Ilizarov external fixation of both condyles (injuries 33-C according to AO/ASIF classification) starts with insertion of two crossing proximal basic wires at the level of the central third of the segment. One is inserted in the sagittal plane and the other at an angle of 30◦ to it: IV,6-12 and IV,1-7. With uniform displacement of the condyles, the ring support is oriented perpendicular to the biomechanical axis of the limb, i.e. at an angle of about 10◦ to the anatomical axis of the femur (Fig.2.8.2).If one of the condyles has a greater displacement, the support is installed with 10–15◦ of hypercorrection towards the condyle,with more displacement in the proximal direction. The distance between the inner edge of the support and the skin in front and outside must be in the range 30–45 mm. The distance from the skin to the support along the posterior surface must be 25–35 mm more. After orientation of the support, the tensioned wires are fixed to it. The reductionally fixing ring is installed at level VI, the distal (radiotransparent) basic ring of the same diameter is installed at level VIII. These two rings are connected by three rods and the reductionally fixing ring is oriented relative to the soft tissues. A unit of

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2 Specific Aspects of External Fixation

1

2

5

3

4

VI,3-9; VI,2-8 ←→ VIII,5-1 ←◦→ II,2-8; II,4-10 (a) 180 180 150

a

VI,3-9; VI,2-8 —— VIII,3-9; III,9-3; VIII,4-10 180

b

180

(b)

Fig. 2.4.16a,b. Ilizarov external fixation device for fixation of fracture 33-B2.1

a

Fig. 2.4.17a,b. CEF device for fixation of fracture 33-C1 (a). The proximal support IV,7-1 is dismantled in the operating room after reduction and stabilization of the reductionally fixing support by half-pin V,8,120. After 4–6 weeks under aseptic conditions wires VIII,2-8 and VIII,10-4 are cut off at the anterior surface after maximally displacing the soft tissue towards the bone. Thus these wires become console transosseous elements VIII,8,90 and VIII,4,90 (b) allowing movement of the knee

b 1

9

4

5

6

7

8

2

3

IV,7-1 —— V,8,120; VI,3-9 →← VIII,3-9; III,9-3; VIII,2-8; VIII,4-10 ←◦→ II,3-9; III,1,70 (a) 195 180 3/4 180 3/4 160 V,8,120; VI,3-9 →← VIII,3-9; III,9-3; VIII,8,90; VIII,4,90 180

3/4 180

(b)

2.4 Fractures of the Femur

two rings is then connected by three rods to the proximal basic support. As the proximal support usually has a larger standard size, connection plates are used for connection. When the proximal basic support is properly installed, the connection bars are parallel to the anatomical axis of the femur. The support II,2-8; II,4-10 is mounted on the upper third of the shin and connected by three or four hinges to the basic support of the femur. After the device is mounted between the distal support of the femur and the support applied to the lower leg, a distraction force is applied mostly on the side of the greater displacement of the condyle. Radiographs are obtained or an image intensifier is used. To eliminate residual displacement of the proximal fragment the wire with a stop VI,3-9 or VI,9-3 is inserted at the level of the reductionally fixing ring. If no reduction is achieved by ligamentotaxis and a condyle needs to be brought down further, it is brought down using a wire inserted in the sagittal plane as shown in Fig. 2.4.16a. After congruence of the articular surfaces is achieved, two wires with stops VIII,3-9 and VIII,9-3 are inserted from opposite directions. Additional rigidity of external fixation is provided by wires VIII,2-8 and VIII,4-10. After that unless there are special indications for knee joint fixation, the support can be removed from the lower leg. After insertion and fixation of the wire VI,2-8 the proximal support can be removed. Such an assembly (two supports on the femur) can be used as the initial one in cases when the experience of application of external fixation allows assembling the device, avoiding the need for additional reduction of the proximal fragment. It should be noted that “closed” external fixation of fractures 33-B and 33-C is not always feasible. The use of an image intensifier and arthroscopic monitoring considerably facilitates reduction. Besides, arthroscopic cleansing of the joint with removal of small bone splinters and cartilage fragments is a significant component in the prevention of traumatic deforming arthrosis. However, in the case of failure, it is necessary to use open apposition of the fragments. If considered appropriate, bone autoplasty is used. When it is impossible to perform full-volume external fixation, the fracture can be immobilized by a fixation device based on two supports. The proximal support is installed at level VI of the femur and the distal support is installed at level II of the lower leg. The device assembly can be of the wire type VI,3-9; VI,2-8 ←◦→ II,2-8; II,4-10 or of the hybrid wire-pin type V,8,120; VI,3-9 ←◦→ II,3-9; III,1,70. After the final radiographs have been obtained, the patient is transported to the ward.

2.4.4

171

Patella (91.1-)

The operation is performed with the knee in maximum extension. To achieve this, a cushion is placed under the heel. Osteosynthesis must be preceded by puncture of the knee joint to remove blood and effusion ﬂuid. The proximal fragment is brought down into contact with the distal fragment using a single-tooth hook. Reduction moment is determined by disappearance of the diastasis on palpation. To avoid displacement of the proximal fragment upwards, it is temporarily fixed to the femur by a wire inserted in the sagittal plane [10]. For transverse and short oblique fractures, wires with a stop are then inserted through the proximal and distal fragments in the frontal plane in the opposite direction. During insertion of the wire through the proximal fragment, the skin is maximally displaced downwards. The wires must be located in the splinters in one horizontal plane to avoid tilt during compression. Therefore, before insertion of the wires, the anterior and posterior edges of the bone must be marked with needles. The tensioned wires are fixed in half-rings connected by two or three rods. A comparison radiograph is obtained in two planes or an image intensifier is used. The reduction is facilitated by the use of arthroscopic monitoring. If lateral displacement of the fragments in two planes has been eliminated, the wire fixing the proximal fragment to the femur is removed. By bringing the half-rings closer on the half-pins, compression is created at the junction of the fragments (Fig. 2.4.18a). If comparison radiographs show the need for further reduction, the fragments are additionally stabilized. A 2-mm console wire in inserted in each fragment in the sagittal plane or 3-mm half-pins are used. The console wires are fixed to the half-rings. Such stabilization of the proximal fragments can be performed using a diafixing wire, the guiding end of which is removed from the femur. Final reduction is performed by mutual displacement of the supports by the necessary amount. If after that the openings of the half-rings do not coincide (warping of the half-pins is impossible!), connection plates are additionally used. If one or both half-rings are not perpendicular to the anatomical axis of the fragment, it is necessary to use hinges to connect the supports (Fig. 2.4.18b). Shved and Sysenko [10] developed the method of external fixation of the patella based on an Ilizarov minidevice. Console wires of diameter 1.8–2 mm are used as transosseous elements. At least two crossing console wires are inserted in each bone fragment. They are used as levers in reduction. After elimination of

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2 Specific Aspects of External Fixation

a

b

Fig. 2.4.18a,b. External fixation devices for fixation of the patella

a

b

c

Fig. 2.4.19a–c. Locations of wires for the external fixation of the patella according to Shved and Sysenko [10]

displacement of the fragments, a diafixing wire with a stop is inserted through them (two wires in splintered fractures). Both ends of this wire are bent and fixed at the ends of the connection rod performing in this case the function of an external support.The free ends of the console wires are also fixed to this rod. The design of the minidevice allows the application of a compression force at the junction of the fragments. Figure 2.4.19 shows various arrangements for the insertion of the transosseous elements in patella external fixation. With a small distal fragment,or the need for restoration of the patella ligament (for example after removal of the distal pole), a two-thirds or three-quarter ring support is applied to the lower leg: I,2-8; I,4-10; II,3-9 or I,9-3; II,1,70. It is connected to the basic device. This technique avoids immobilization of the knee joint. For transportation to the ward a cushion is placed under the knee to ensure 30–45◦ ﬂexion.

2.5 Fractures of the Tibia and Fibula Osteosynthesis of the tibia and fibula (Figs. 2.5.1– 2.5.21) is performed with wires of diameter 1.8–2 mm. In CEF, half-pins of diameter 5 and 6 mm are used together with wires. The osteosynthesis set must also

include 2-mm console wires with a stop with various length of the part to be inserted in the bone (5, 10, 15 and 20 mm). External fixation of the bones of the lower leg is generally performed with external supports of the same standard size, but if the difference in circumference between the upper and lower thirds of the segment is more than 5–6 cm external supports of two standard sizes can be used. To ensure knee joint ﬂexion the supports placed at the first three levels of the lower leg (levels 0, I and II) must be open, i.e. two-thirds or three-quarter rings. In osteosynthesis of the juxtaarticular and intraarticular fractures (41-, 43- and 44- according to the AO/ASIF classification) the use radiotransparent external supports is recommended. For insertion of transosseous elements through the soft tissues of the anterior semicircle of the lower leg at the first four levels (levels 0 to III) the knee is placed in ﬂexion at 90–120◦. For insertion of wires through the posterior semicircle of the lower leg the knee joint is placed in the neutral position. To prevent pin-induced stiffness of the ankle with insertion of wires and half-pins through the anterior aspect of the lower leg at the four distal levels, the foot is placed in plantar ﬂexion of 40◦ . For insertion of transosseous elements through the posterior aspect of the lower leg the foot is placed in maximum dorsal ﬂexion

2.5 Fractures of the Tibia and Fibula

173

Fig. 2.5.1. Orientation of the basic supports for external fixation of fractures of the lower leg. The markedly eccentric position of the tibia relative to the soft tissue determines the orientation of the supports. The distances from the proximal basic support to the skin of the anterior and inner aspects of the segment (planes of positions 12 and 3) are in the range 1.5–2.5 cm, and to the skin of the posterior aspect of the segment is in the range 2–3 cm more. The distance from the inner edge of the distal basic support to the tibial axis in the plane of positions 3 and 12 is the same as the distance for the proximal basic support. These distances are calculated from radiographs [11]. In simplified terms, the distances from the bone to the rings of the basic supports in the plane of positions 3 and 12 are the same [12]

(Fig.1.6.2).When it is impossible to change the position of the joints the required amount the skin is displaced manually or by using a thin hook in the direction of its natural reposition relative to the bone during movements in the adjacent joint. When only reference positions are used for transosseous element insertion, there is no need to change the position of the joints. However, preliminary skin repositioning (before insertion of the transosseous elements) is necessary in segment elongation, deformity correction, bilocal osteosynthesis and other situations when it is necessary to create a “stock” of soft tissue. Before fixation of transosseous elements the external support must be appropriately oriented relative to the anatomical axis of the bone fragment and the soft tissue (Fig. 2.5.1). The external supports must be located perpendicular to the anatomical (central diaphyseal) axis of the bone fragment to which they are fixed except when they are purposely placed in the positions of hypercorrection discussed below. In CEF the device is assembled so that the junctions of the intermediate reductionally fixing supports and the distal basic support are located in the frontal plane. This allows the posterior half-rings to be disconnected during the fixation period using the techniques of modular transformation. The proximal support, a three-quarter ring, can be disconnected from the device assembled in this way and the entire structure sent for sterilization. The ends of the wires and half-pins that are at some distance from the support after it is given the necessary spatial orientation are fixed using posts and/or spacing washers. Unless the half-pins are basic or reductionally fixing transosseous elements they are stabilized in the

external supports only after the necessary spatial orientation of the bone fragments has been achieved. If a half-pin is inserted in the bone not parallel to the external support it is fixed by two posts, female and male. The half-pin can be fixed to the support or the post using an L-shaped clip similar to the use of the laterally slotted wire fixator. The next sections in which particular methods of fixation are described contain phrases similar to: “When the device module is properly installed its connection rods are parallel to the anatomical axis of the bone fragment.” However, it should be born in mind that when the basic support is fixed only on wires (wire) its position can change due to bending of the wires from the weight of the rings and connection rods.In such situations to control the module orientation it should be held while the wires are straightened. Reduction by wires is performed by relocation of the bone fragment with the help of a stop and arched bending of the wire (Fig. 1.6.9). Reduction with halfpins is mostly achieved by pushing or pulling, and with console wires with a stop only by pushing (Fig. 1.6.10). It is also possible to use any reduction technique together with mutual displacement of the external supports (Figs.1.6.4–1.6.8).Large splinters are reduced and fixed using wires with stops or console wires with stops (Fig. 1.6.13). When the splinter is located between the tibia and fibula reduction is achieved using a fork device (Figs. 1.4.8 and 1.6.14). In all the schemes of osteosynthesis illustrated in the figures the direction of insertion of reductional transosseous elements (wires, half-pins) and the positions of the stops on the wires are conventional and shown only as examples. In practice, one should be

174

2 Specific Aspects of External Fixation

a

b

c

Fig. 2.5.2a–c. Skeletal traction in diaphyseal fractures of the tibia and fibula. The patient is placed on the orthopaedic traction table, and a regular attachment to the table is installed under the distal third of the femur ensuring flexion of the knee of 40–◦ 50◦ . If a soft cushion is used instead of the attachment, it should be provided with a rest located on the inner surface of the knee. A wire is inserted through the heel bone and fixed under tension condition in the half-ring of the traction angle of the table (a). To reduce the fragment displacement at an angle open outwards, traction is performed at an angle of 30–40◦ open inwards rather than along the axis of the segment (b,c [13]). To eliminate rotational displacement, the foot is oriented such that the first web space and the middle of the patella (the ridge of the tibial bone of the proximal fragment) are aligned

guided by the actual residual displacement of the bone fragments. To avoid injury to the great vessels and nerves one should use the safe positions at the levels identified in the atlas and recommended for insertion of reductionally fixing transosseous elements.The sizes of the external supports in the schemes illustrated in the figures are also conventional. External fixation of the tibia is generally performed under regional anaesthesia. Transportation immobilization is removed on the surgical table after induction of anaesthesia. The methods of external fixation of diaphyseal fractures of the bones of the lower leg and extraarticular fractures of the proximal and distal parts of the tibia requires preliminary rough elimination of the displacement of the bone fragments by skeletal traction (Fig. 2.5.2).

The location of the bone fragments is improved by axial traction and manual manipulation. To facilitate reduction the injured segment is “overtractioned” by up to 7–10 mm with monitoring of the distraction force in the attachment by comparison with the contralateral lower leg.Radioopaque markers (injection needles, fragments of wires) are fixed on the skin and comparison radiographs are obtained in two standard planes or an image intensifier is used. Lines corresponding to the anatomical axis of every bone fragment are drawn on the skin of the anterior and external aspect of the segment. Using the special device shown in Fig. 1.8.2 the levels for transosseous elements insertion are marked. With accumulating clinical experience of external fixation of diaphyseal fractures, the need for comparison radiographs during skeletal traction is reduce. The operative field is treated and covered with linen.

2.5 Fractures of the Tibia and Fibula

Radiographic confirmation of an accurate reduction on the surgical table is a rule of external fixation of closed fractures. The practice of hastily assembling an external fixation device in the operating room and performing the reduction after the patient has been transferred to the clinical department with daily stepwise radiographic monitoring of the manipulations is an unsatisfactory and discredited method of external fixation. An exception to this rule is when a fixation device is applied as described below. After the osteosynthesis has been performed, it is necessary to check passive movements in the joints adjacent to the segment operated upon.Tension in the soft tissues as a result of the insertion of the transosseous elements must be eliminated by releasing the skin and, if necessary, the fascia and muscles.

2.5.1

Proximal Tibia and Fibula (41-)

In fractures of the proximal lower leg, skeletal traction is applied in extraarticular injuries (41-A). As has been pointed out, this is done using a wire inserted through the heel bone. In intraarticular fractures (41-B, 41-C) “disciplinary”traction is applied for convenience of application of the basic supports of the device.If required, the knee joint is punctured to allow aspiration of blood and effusion ﬂuid. In extraarticular fractures (41-A2, 41-A3 according to AO/ASIF classification) as well as epiphysiolyses, osteoepiphysiolyses, the device assembly is analogous to the one used for fractures of the proximal third of the diaphysis of the tibia (Figs. 2.5.5 and 2.5.6). Ilizarov external fixation starts with insertion of two crossing wires (0,2-8 and 0,4-10) at the level of the proximal epimetaphysis of the tibia. The proximal basic ring (a two-thirds or three-quarter ring) is oriented relative to the soft tissues as stated in the introductory section. Special attention should be paid to installing the ring perpendicular to the anatomical axis of the proximal fragment. Only then are the wires tensioned and fixed to the support. At the level of the distal metaphysis of the tibia, crossing distal basic wires VII,2-8 and VII,4-10 are inserted. A module is then mounted on the lower leg including the reductionally fixing ring at level III and the distal basic ring. This module is connected by three rods to the proximal basic support, without tightening the nuts on the rods so they can be moved in the holes of the ring. The distal basic ring is oriented relative to the soft tissues and installed so that the rods connecting the reductionally fixing and the distal basic supports are parallel to the anatomical axis of the distal fragment. Only then are the distal basic wires tensioned and fixed to the ring. If one end of the distal basic wire(s) appears to be beyond the plane of the support, it is fixed using a post.

175

The rods are stabilized between the proximal basic and reductionally fixing supports; a distraction force is then applied to create an interfragmental diastasis of 4–5 mm if this was impossible by skeletal traction. Radiographs in two standard planes are obtained or ﬂuoroscopy is used. To eliminate residual displacement of the distal fragment at the level of the reductionally fixing ring a wire with a stop III,3-9 or III,9-3 is inserted. If the proximal fragment is small a wire cannot be used for its final reduction. However, wire I,3-9 is inserted to increase the rigidity of the osteosynthesis. The residual displacement of the fragments is eliminated by moving the distal transosseous module relative to the proximal support. If the ligaments of the knee are injured, in the presence of marked oedema of the soft tissue with haemosynovitis, or in other situations when fixation of the knee joint is recommended, a support based on the wires VII,2-8; VII,4-10 is applied to the femur, or the combined support VI,8,120; VII,3-9 is used. Ilizarov external fixation of isolated fractures of the condyles of the tibia (injuries 41-B according to the AO/ASIF classification) starts with insertion of two crossing wires in the lower third of the femur; after tensioning, the wires are fixed to the ring support: VII,2-8; VII,4-10. The support is installed parallel to the joint surface of the femoral condyles. If the condyle is considerably displaced, the basic support should be installed with 7–10◦ hypercorrection with the ring inclined towards the injury. The proximal basic ring of the lower leg, which is preferably radiotransparent, is oriented relative to the soft tissues and connected by three or four hinges to the support on the femur. Crossing wires IV,3-9 and IV,4-10 are then inserted through the tibia at the level of its middle third. The distal basic ring is placed at level IV and connected by three rods to the proximal basic support of the lower leg without tightening the nuts on the connection rods. The distal support is oriented so that it is inclined 7– 10◦ towards the injury, and only then are the wires tensioned in the support. Preliminary installation of the outermost supports in a position of hypercorrection facilitates parallel positioning of all the ring supports after the main distraction force is applied on the side of the injury.Comparison radiographs are obtained (an image intensifier is used) or arthroscopic monitoring is used. If no reduction is achieved by ligamentotaxis and additional elevation of a condyle is required, a wire with a stop is inserted through it close to the sagittal plane. The position of the stop depends on whether the condyle is displaced forward or backward. The wire is tensioned in the support which is installed at the level of the condyles of the lower leg. A uniform dis-

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2 Specific Aspects of External Fixation

Fig.2.5.3a,b. Ilizarov external fixation devices for fixation of fracture 41-B1.2

1

2

5

3

4

VII,2-8; VII,4-10 —◦— I,5-1 ←→ IV,3-9; IV,4-10 (a) 180 150 150

a

b

traction force is then applied to all the rods between the supports installed on the lower leg (Fig. 2.5.3a). If the comparison radiographs confirm elevation of the condyle by the required amount, a wire with a stop in inserted in the frontal plane: 0,3-9 in fractures of the endocondyle or 0,9-3 in fractures of the ectocondyle. Then, at a distance of 15–20 mm from the exit point of the wire to the front or to the rear, a wire is inserted in the opposite direction. In the presence of osteoporosis, it is best to use wires with stops bent in the form of a corkscrew. The wire inserted in the sagittal plane is removed. Additional rigidity of the osteosynthesis is provided by insertion of an additional wire through the injured condyle. Then, unless there are special indications to fixation of the knee joint, the support can be dismantled from the femur (Fig. 2.5.3b). Ilizarov external fixation of both condyles (injuries 41-C according to the AO/ASIF classification) starts with insertion of two crossing wires in the lower third of the femur that are fixed after tensioning to the ring support: VII,2-8; VII,4-10. In the case of uniform displacement of the condyles, the support must be located parallel to the joint surface of the femoral condyles.The proximal basic ring of the lower leg, which is preferably radiotransparent,is installed at the level of the condyles and oriented relative to the soft tissues and connected by three or four hinges to the support on the femur. The reductionally fixing ring is placed at level IV and connected by three rods to the proximal basic support. The distal basic ring is placed at level VII and connected by three rods to the reductionally fixing ring. The connection rods of this module must be parallel to the anatomical axis of the primary fragment of the

0,3-9; 0,9-3; I,4-10 —— IV,3-9; IV,4-10 150

150

(b)

tibia. Wires VII,2-8 and VII,4-10 are then inserted in the plane of the distal basic ring, tensioned and fixed to the support. After mounting the device, a distraction force is applied between the auxiliary support applied to the hip and the proximal basic support of the lower leg with more force on the side of the greater displacement of the condyle. A comparison radiograph is obtained (ﬂuoroscopy is used) or arthroscopic monitoring is used. To eliminate residual displacement of the proximal fragment at the level of the reductionally fixing ring a wire with a stop is inserted: IV,3-9 or IV,9-3. If no reduction was achieved by ligamentotaxis and additional elevation of a condyle is required, a wire is inserted in the sagittal plane as shown in Fig. 2.5.3a. If required, both condyles are consecutively reduced using this technique. After congruity of the joint surfaces has been achieved, two wires with stops are inserted in opposite directions: 0,3-9 and 0,9-3. Additional rigidity of the osteosynthesis is ensured by insertion of wires I,2-8 and I,4-10. Unless there are indications to fixation of the knee joint, the support can be dismantled from the femur. Wire IV,4-10 is then inserted, tensioned and fixed to the reductionally fixing support; the distal basic support can be dismantled. Such an assembly (two supports on the lower leg) can be used as the initial one in cases where the device can be assembled in such a way that no additional reduction of the distal fragment is required. It should be noted that the use of the imaging intensifier or arthroscopic monitoring facilitates reduction considerably. Also cleansing of the joint to remove

2.5 Fractures of the Tibia and Fibula

a

b 1

2

6

7

177

c 8

9

4

5

3

VI,8,120; VII,3-9 ←◦→ 0,3-9; 0,9-3; I,2-8; I,10-4 —— IV,3-9; V,12,70 —— VI,3-9 (a) 3/4 180 3/4 160 160 160 0,3-9; 0,9-3; I,2,90; I,10,90 —— IV,3-9; V,12,70

(b)

0,3-9; 0,9-3; I,8-2; I,4-10 —— III,12,90; VI,12,90

(c)

3/4 160

3/4 160

1/2 160

mon

Fig.2.5.4a–c. CEF devices for fixation of fracture 41-C1.3. The distal support, VI,3-9, is removed after reduction and stabilization of the reduction fixation support by means of half-pin V,12,70. After 4–5 weeks under aseptic conditions, wires I,2-8 and I,104 are cut off at the posterior surface after maximally displacing the soft tissues towards the bone. Thus, the wires become console transosseous elements I,2,90 and I,10,90. This allows movement of the knee. At the same time to reduce the bulkiness of the device and to make it more dynamic, the posterior half-ring of the distal basic support is removed (b). The hybrid assembly (c) is smaller due to the use of a monolateral support to which the basic half-pins are fixed for fixation of the long fragment of the diaphysis. However, this assembly has a limited reduction ability as distraction is possible along the anterior and, partly, lateral surfaces of the segment

small bone splinters and cartilage fragments is a significant component of the prevention of traumatic deforming arthrosis. However, in fractures 41-B and 41-C, closed reduction is not always feasible. In these cases, it is necessary to start open alignment of the fragments; the issue of bone autoplasty is addressed depending on the indications. If it is impossible to perform full-volume osteosynthesis, the fracture can be immobilized by a fixation

device based on two supports. The proximal support is installed at level VII of the femur, the distal one at level II of the lower leg. The device assembly can be of the wire type or hybrid wire-pin type: Wire type: VII,2-8; VII,4-10 ←o→ IV,3-9; IV,4-10 Hybrid type: VI,8,120; VII,3-9 ←o→ IV,3-9; V,12,70 After the final radiography, the patient is transferred to the ward.

178

2 Specific Aspects of External Fixation

1

2

5

7

6

3

4

(I,8-2)I,8-2; I,4-10; II,3-9 —— III,9-3; IV,3-9 —— (VIII,8-2)VIII,8-2; VIII,4-10 150

150

150

Fig. 2.5.5. Ilizarov external fixation device for fixation of fracture 42-B2.1

a

b 1

3

6

5

c 4

7

2

I,9-3; II,3-9; II,1,70 —— III,10,120; IV,3-9; VI,12,70 →← VII,9-3 (a) 3/4 150 150 150 I,9-3; II,3-9; II,1,70 —— III,10,120; IV,3-9; VI,12,70

(b)

I,9-3; II,3-9; II,1,70 —— IV,3-9; VI,12,70

(c)

3/4 150

3/4 150

2.5.2

150

1/2 150

Diaphyseal Fractures (42-)

2.5.2.1 Proximal Third Ilizarov external fixation of fractures of the proximal third of the tibial diaphysis (injuries 42-A1.1, 42-A2.1,

Fig. 2.5.6a–c. CEF device for fixation of fracture 42-B2.1 (a). Fixation of half-pin V,12,70 to the reductionally fixing support allows the distal basic support VII,9-3 to be removed within 5–7 weeks (b). By modular transformation, the posterior half-ring of the reductionally fixing support can be removed within 9–11 weeks (c). Modular transformation is discussed in more detail in section 2.17

42-A3.1, 42-B1.1, 42-B2.1, 42-B3.1, 42-C1, 42-C3 according to the AO/ASIF classification) starts with the insertion of two crossing proximal basic wires at the level of the tibial tuberosity. One of them is inserted only through the tibial bone and the other is inserted

2.5 Fractures of the Tibia and Fibula

through the head of the fibula and the tibial metaphysis: I,4-10 and (I,8-2)I,8-2.2 The distal basic wires (VIII,82)VIII,8-2 and VIII,4-10 are then inserted at the level of the distal metaphysis. The bolts connecting the half-rings at one side are taken out of the preliminarily assembled device. The device is opened, placed under the shin and the halfrings reconnected. The proximal basic ring is installed perpendicular to the anatomical axis of the proximal fragment oriented relative to the soft tissues, as described in the introductory section, and the tensioned wires are fixed to it. The nuts of the connection rods are retracted 3–4 mm from the reductionally fixing ring that is installed at level IV. The distal basic ring is oriented relative to the anatomical axis of the distal fragment and soft tissues, and the distal basic wires are fixed to it after tensioning. If the wires are not perpendicular to the anatomical axis of the distal fragment, they are fixed to the ring using console posts. The reductionally fixing support is then restabilized by tightening the nuts of the connection rods. A distraction force is applied to create an interfragmental diastasis of 4–5 mm if this was not achieved by skeletal traction. Radiographs are obtained in two standard planes or an image intensifier is used. To eliminate residual displacement of the proximal bone fragment at level II,a wire is inserted in the frontal plane, for example II,3-9 or II,9-3. To eliminate residual displacement of the distal fragment, a second reductionally fixing wire is inserted at the level of the intermediate support: IV,3-9 or IV,9-3. Using known techniques (relocation of the bone fragment using a stop and arched bending of the wire), the proximal and then the distal bone fragments are reduced. Reduction must be confirmed radiographically.Large splinters are fixed by console wires, paraosseously inserted wires, or wires with stops, as shown in Fig. 2.5.5. 2.5.2.2 Middle Third Ilizarov external fixation of fractures of the middle third of the tibial diaphysis (injuries 42-A1.2, 42-A2.2, 42-A3.2, 42-B1.2, 42-B2.2, 42-B3.2, 42-C1, 42-C3 accord2

Bear in mind that according to MUDEF, the indication for transosseous elements to be inserted through the fibula is given in parentheses. If the wire is simultaneously inserted through both bones, it is designated in accordance with the priority with which the guiding end of the wire was inserted through the fibula and tibia. For example, the notation (I,8-2)I,8-2 designates a wire with a stop that was inserted from the side of the head of the fibula and then through the tibia. The notation I,8-2 designates a wire inserted through the tibia a bit to the front of the head of the fibula. The notation (III,6-12) designates a wire inserted at level III in the sagittal plane only through the fibula.

179

ing to the AO/ASIF classification) starts with the insertion of two crossing proximal basic wires at the level of the tibial tuberosity. One is inserted only through the tibial bone and the other through the head of the fibula and the metaphysis of the tibia: I,4-10 and (I,82)I,8-2. Two distal basic wires, (VIII,8-2)VIII,8-2 and VIII,4-10, are then inserted at the level of the distal metaphysis. The proximal reductionally fixing ring must be located at level III or level IV, depending on the level of the fracture. The distal reductionally fixing ring must be at level V (or level VI). If the device was preliminarily assembled, it is opened by removal of the bolts connecting the half-rings at one side. The structure is placed under the shin, installed perpendicular to the anatomical axis of the proximal fragment, oriented relative to the soft tissues,as explained in the introductory section, and the tensioned wires are fixed to it. The nuts on the connection rods are retracted 3-4 mm from the reductionally fixing supports. The distal basic ring is then oriented relative to the anatomical axis of the distal fragment and soft tissues and the distal basic wires are fixed to it after tensioning. If the wires were not inserted perpendicular to the anatomical axis of the distal fragment, they are fixed to the ring using console posts. The reductionally fixing supports are then stabilized and a distraction force is applied to create an interfragmental diastasis of 4–5 mm if this could not be achieved by skeletal traction. Radiographs are obtained in two standard planes or an image intensifier is used. To eliminate residual displacement of the proximal bone fragment, a wire is inserted at the level of the proximal reductionally fixing ring, for example III,3-9. To eliminate residual displacement of the distal fragment a second reductionally fixing wire is inserted at the level of the second intermediate ring, for example V,3-9. Using known techniques (relocation of the bone fragment using a stop together with arched bending of the wire), the proximal and then the distal bone fragments are consecutively reduced. Reduction must be confirmed radiographically. Large splinters are fixed by console wires, paraosseously inserted wires or wires with a stop, as shown in Fig. 2.5.7. 2.5.2.3 Distal Third Ilizarov external fixation of fractures of the distal third of the tibial diaphysis (injuries 42-A1.3, 42-A2.3, 42A3.3, 42-B1.3, 42-B2.3, 42-B3.3, 42-C1, 42-C3 according to the AO/ASIF classification) starts with the insertion of two crossing proximal basic wires at the level of the tibial tuberosity. One is inserted only through the tibial bone and the other through the head of the fibula and the metaphysis of the tibial bone: I,4-10 and (I,8-2)I,8-

180

2 Specific Aspects of External Fixation

1

2

5

7

(I,8-2)I,8-2; I,4-10 —— V,3-9; VI,3,90 —— 150

6

150

3

4

VII,9-3; (VIII,8-2)VIII,8-2; VIII,4-10 150

1

2

5

7

(I,8-2)I,8-2; I,4-10 —— III,3-9; IV,9-3 —— 150

6

150

3

Fig. 2.5.10. Ilizarov external fixation device for fixation of fracture 42-B2.3

4

V,3-9 —— (VIII,8-2)VIII,8-2; VIII,4-10 150

150

Fig. 2.5.7. Ilizarov external fixation device for fixation of fracture 42-B2.2

2. The distal basic wires (VIII,8-2)VIII,8-2 and VIII,410 are then inserted at the level of the distal metaphysis. The bolts connecting the half-rings at one side are taken out of the preliminarily assembled device. The device is opened, placed under the lower leg and the half-rings reconnected. The proximal basic ring is installed perpendicular to the anatomical axis of the proximal fragment, oriented relative to the soft tissues as described in the introductory section, and the tensioned wires are fixed to it. The nuts of the connection rods are retracted 3–4 mm from the reductionally fixing ring that is installed at level V. The distal basic ring is oriented relative to the anatomical axis of the distal fragment soft tissues and the distal basic wires are fixed to it after tensioning. If the wires were not inserted perpendicular to the anatomical axis of the distal fragment, they are fixed to the ring using posts. The reductionally fixing support is then restabilized and a distraction force is applied to create an interfragmental diastasis of 5 mm if this could not be achieved by skeletal traction. Radiographs are obtained in two standard planes or an image intensifier is used.

To eliminate residual displacement of the proximal bone fragment at level V, a reductionally fixing wire is inserted in the frontal plane, for example V,3-9. To eliminate residual displacement of the distal fragment a second reductionally fixing wire is inserted, for example VII,3-9. Using known techniques (relocation of the bone fragment using a stop together with bending of the wire), the proximal and then the distal bone fragments are consecutively reduced. Reduction must be confirmed radiographically.Large splinters are fixed using console wires with stops, paraosseously inserted wires, or console wires, as shown in Fig. 2.5.10. In patients with injuries to both lower extremities or in overweight patients in whom supports of diameter more than 160 mm need to be used, it is necessary to increase the rigidity of bone fragment fixation. In such cases osteosynthesis involves insertion of additional wires at the level of the reductionally fixing supports and in the case of the CEF at the level of the basic supports. In cases of isolated injury to the tibia wire I,8-2 inserted before the head of the fibula is used instead of wire (I,8-2)VIII,8-2. In these cases wire VIII,3-9 is used instead of wire (VIII,8-2)VIII,8-2. If separation of the distal tibiofibular syndesmosis is a possibility, wire (VIII,8-2)VIII,8-2 is inserted after reduction of the bone fragments. When full-volume external fixation of diaphyseal fractures of the lower leg is impossible, for example in

2.5 Fractures of the Tibia and Fibula

a

b 1

7

3

181

c

5

6

4

2

8

I,9-3 →← II,12,120; IV,3-9; V,2,80 —— V,10,120; VI,9-3; VII,1,70 ←→ (VIII,8-2)VIII,8-2 (a) 3/4 150 150 150 150 II,12,120; IV,3-9; V,2,80 —— V,9,110; VI,9-3; VII,1,70

(b)

II,12,120; IV,3-9 —— VI,9-3; VII,1,70

(c)

150

150

1/2 150

1/2 150

Fig. 2.5.8a–c. CEF device for fixation of fracture 42-C1.3 (a). Fixation of the half pins II.12.120 and VII.1.70 to the reductionally fixing supports allows the basic supports to be removed within 5–7 weeks (b). The posterior half-ring of the reductionally fixing supports can be removed within 9–11 weeks (c). Additional information is provided in section 2.17

a

b 1

5

3

c 4

6

2

I,9-3 —— II,2,120; IV,12,90 —— V,12,90; VII,1,70 —— (VIII,8-2)VIII,8-2 (a) 3/4 160 160 160 160 II,2,120;IV,90 —— V,12,90; VII,1,70

(b)

II,2,120; IV,90 —— V,12,90; VII,1,70

(c)

160

1/4 160

160

1/4 160

Fig. 2.5.9a–c. CEF variant device for double-plane bone fragment reduction using half-pins(a). The basic supports can be removed after 5–7 weeks (b). The posterior three-fourths ring of the reductionally fixing supports can be removed within 9–11 weeks (c)

182

2 Specific Aspects of External Fixation

a

b 1

5

4

3

c 2

6

II,9-3 ←→ III,12,70; V,3-9 →← VII,9-3; VII,1,70; (VIII,8-2)VIII,8-2 (a) 3/4 150 150 150 III,12,70; V,3-9 →← VII,9-3; VII,1,70; (VIII,8-2)VIII,8-2

(b)

III,12,70; V,3-9 →← VII,9-3; VII,1,70; (VIII,8-2)VIII,8-2

(c)

150

150

1/2 150

150

Fig. 2.5.11a–c. CEF device for fixation of fracture 42-A3.3 (a). Fixation of half-pin IV.12.70 to the reductionally fixing support allows the proximal basic support II,9-3 to be removed within 5–7 weeks (b). The posterior half-ring of the reductionally fixing support can be removed within 9–11 weeks by modular transformation (c). Additional information is provided in section 2.17

a

b 1

3

8

5

6

7

4

9

2

I,9-3; II,3-9; II,1,90 →← III,3-9; IV,1,90 —— V,10,110; VI,3-9; VII,1,70 —— (VIII,8-2)VIII,8-2 (a) 3/4 160 160 160 160 I,9-3; II,3-9; II,1,90 →← III,3-9; IV,1,90 —— V,10,110; VI,3-9; VII,1,70 3/4 160

1/2 160

1/2 160

(b)

Fig. 2.5.12a,b. CEF device for fixation of fracture 42-C2.2. Half-pin IV,1,90 is used for reduction of the distal end of the intermediate fragment and its further fixation. Console wire with a stop V,10,110 fixes the large splinter of the bone after reduction (a). The distal support is removed 1–1.5 months prior to the planned date of fixation completion, and the posterior half-rings of the reductionally fixing supports are removed 2–3 weeks before the date (b)

2.5 Fractures of the Tibia and Fibula

calc.,5–m/tars.V; calc.,7–m/tars.I

a

183

(a)

calc.,2-8; calc.,4-10; m/tars.V–m/tars.I (b)

b

Fig. 2.5.13a,b. External fixation supports for mounting on the foot

the event of mass admission of casualties, it is possible to perform a “fixation” variant of external fixation. Two crossing wires are inserted through the proximal and distal metaphyses of the bones of the lower leg. They are fixed under tension in two ring supports. A moderate distraction force is applied between the supports: I,8-2; I,4-10 ↔ (VIII,8-2)VIII,8-2; VIII,4-10. The “fixation” variant of external fixation has indisputable advantages over skeletal traction: less bulkiness, greater mobility of the patient, the possibility of reduction by both skeletal traction (elastic energy) and by insertion of reductionally fixing transosseous elements during final assembly of the device. After final radiography, skeletal traction is dismantled and the patient is transferred to the ward. During transportation there must be a soft cushion under the knee joint to ensure ﬂexion at 30–40◦ .

2.5.3

Distal Tibia and Fibula (43-)

Ilizarov external fixation of fractures in group 43, according to the OA/ASIF classification, starts with insertion of two crossing proximal basic wires at the level of the proximal tibiofibular joint. One wire is inserted through both bones.The proximal basic ring is installed perpendicular to the anatomical axis of the tibia, oriented relative to the soft tissues and the tensioned wires I,4-10; (I,8-2)I,8-2 are fixed to it. A reductionally fixing ring is installed at level VI of the lower leg and connected by three telescopic rods to the basic support, thus forming a proximal transosseous module. External fixation of extraarticular fractures (43-A according to the AO/ASIF classification) as well as of epiphysiolyses and osteoepiphysiolyses is generally performed similarly to intervention for fractures of the distal third of the tibial bone (Figs. 2.5.9 and 2.5.10). After mounting of the proximal transosseous module at the level of the epimetaphysis of the distal frag-

ment perpendicular to its anatomical axis, two crossing wires are inserted: (IX,8-2)IX,8-2 and IX,4-10. The proximal transosseous module is connected to the distal basic support by three or four rods. The nuts of the reductionally fixing support are not tightened to allow movement of the rods in the holes of the ring. The distal basic ring is oriented relative to the soft tissues and installed so that the connecting rods are parallel to the anatomical axis of the distal fragment.Only then are the distal basic wires tensioned and fixed to the ring. The reductionally fixing support is stabilized by tightening the nuts. A distraction force is then applied to create an interfragmental diastasis of 4–5 mm if this could not be achieved by skeletal traction. Radiographs are obtained in two standard planes or an image intensifier is used. To eliminate residual displacement of the proximal fragment at the level of the reductionally fixing ring, a wire with a stop is inserted:VI,3-9 orVI,9-3.A small distal fragment cannot be reduced using a wire. However, in order to increase the rigidity of the osteosynthesis wire VIII,3-9 can be inserted. Residual displacement is eliminated by mutual displacement of the external supports (Figs. 1.6.4–1.6.8). If fixation of the distal fragment is unstable, for example due to osteoporosis, the ankle joint is temporarily fixed. Two wires are inserted through the heel bone, tensioned in the elongated support and connected to the distal basic support of the device. To make the structure less bulky, the wire-type device can be transformed into a hybrid wire-pin device. After the half-pin V,12,120 is inserted and fixed to the reductionally fixing support, the proximal support can be dismantled (Fig. 2.5.13b). If the device was mounted with the junctions of the half-rings oriented in the frontal plane, the posterior half-ring of the wire-pin support is dismantled within 2–3 weeks.

184

2 Specific Aspects of External Fixation

Ilizarov external fixation of intraarticular fractures of the distal part of the bones of the lower leg (injuries 43-B, 43-C according to the AO/ASIF classification; pylon or plafond fractures) also starts with mounting of a module based on two supports: the proximal basic support and the reductionally fixing support. The ring support, preferably made from a radiotransparent material, is fixed to the module. The support must be located at level VIII of the lower leg. The support on the foot is then mounted (Fig. 2.5.13). The support is grasped and an attempt is made to reduce the bone splinters manually. The distal support is then connected by three or four rods to the basic device and a distraction force is applied. Comparison radiographs are obtained or an image intensifier is used. Wire VI,3-9 (orVI,9-3) is then inserted at the level of the reductionally fixing ring.It helps to correct the position of the proximal fragment and stabilize it. If no reduction is achieved by ligamentotaxis, the displaced fragments are brought together using a thin awl, the awl being used as a lever with monitoring using the image intensifier or arthroscopically. It should be noted that the use of arthroscopic monitoring does not just simplify reduction. Cleansing of the joint by the removal of small bone splinters and cartilage fragments is an important component in the prevention of traumatic arthrosis. If congruity of the joint surfaces cannot be restored, open reduction is performed. An advantage of external fixation in this case is the possibility of reducing the danger of devitalization of the splinters through minimization of surgical intervention (which is only required for monitoring the reduction), and unloading of the joint surfaces. Before the first incision the ring support at level VIII is raised on rods to the level of the reductionally fixing support, and the connection rods hindering the manipulation are removed. If the surgical approach is impeded due to soft tissue tension, the distraction force is removed. Standard pairs of wires are used: (VIII,8-2)VIII,8-2 and VIII,4-10 or (IX,8-2)IX,8-2 and IX,4-10 after reduction by a standard method. Additional transosseous elements (wires with a stop, console wires) are inserted according to the location of the splinters. In cases of osteoporosis stops bent in the form of a corkscrew are used. Bone autoplasty is used if considered appropriate. Figure 2.5.14 shows three device assemblies for osteosynthesis of pylon fractures. The hybrid assembly shown in Fig. 2.5.13c has smaller dimensions due to the use of a monolateral support for fixation of the long fragment of the diaphysis, the basic half-pins being fixed to the support. However, one should consider the limited reduction possibilities of this structure, as

distraction is possible along the anterior and partly lateral aspects of the segment. If full-volume osteosynthesis is impossible, the fracture can be immobilized using a “fixation” device based on two supports instead of skeletal traction: VI,8-2; VI,4-10 ←→ calc.,2-8; calc.,4-10. After final radiography, the patient is transferred to the ward.

2.5.4

Ankle Injuries (44-)

The operation must be preceded by closed manual reduction of the bone fragments. Classical Ilizarov external fixation of complicated fractures of the ankle joint starts with insertion of two crossing proximal basic wires at the level of the proximal tibiofibular joint, one of the wires being inserted through both bones: I,4-10 and (I,8-2)I,8-2. The proximal basic ring is installed perpendicular to the anatomical (mediodiaphyseal) axis of the tibial bone and oriented relative to the soft tissues, so that the distance between its inner edge and the skin along the anterior and inner aspects is no less than 3–3.5 cm. The tensioned wires are then fixed to the ring. An intermediate ring is installed at level V of the lower leg and connected by three telescopic rods to the basic support. When the device module is properly installed the connection rods are parallel to the anatomical axis of the tibial bone. The distal basic ring, which is preferably radiotransparent, is installed at the level of the distal tibiofibular joint (level VIII) and connected to the intermediate ring by three rods. If a metal ring is used, it is placed somewhat higher – closer to level VII – to avoid problems in reading the radiographs. In this case, the wires are fixed to the support with posts. The sequence of restoration of the anatomical image of the ankle joint must be as follows: 1. Reduction and fixation of fibula fragments (lateral malleolus). 2. Elimination of tibiofibular diastasis. 3. Reduction and fixation of the anteroinferior part of the tibial bone. This reduction is recommended when its value exceeds one-quarter of the joint surface. 4. Performance of stages 1, 2 and 3 eliminates or considerably decreases the dislocation of the foot. 5. Reduction and fixation of the medial malleolus eliminates the dislocation of the foot. In fractures of the fibula, a wire with a stop (VIII,5-11) is inserted through its distal fragment at the level of the distal tibiofibular syndesmosis perpendicular to the intermalleolar line. If the fibula is broken at the level of the syndesmosis, the wire is inserted directly under the fracture: (IX,5-11). The ends of the wire are bent down

2.5 Fractures of the Tibia and Fibula

a

b

185

c

Fig. 2.5.14a–c. External fixation devices for fixation of fractures 43-B and 43-C

a

b

and inward in external incomplete dislocations of the foot or down and outwards in internal incomplete dislocations. The amount of bending is determined by the degree of displacement of the lateral malleolus. The ends of the wire are then fixed to the distal basic ring.

Fig. 2.5.15a,b. External fixation device for reduction and fixation of fractures of the lateral malleolus

In fibula fractures at the level of or below the distal tibiofibular syndesmosis the end of the wire is fixed to the ring using posts.This allows preservation of the orientation of the ring at level VIII. By pulling the anterior end of the wire with a wire tensioner or a distraction

186

2 Specific Aspects of External Fixation

clip, the lateral displacement of the fragments is eliminated; simultaneous pulling at both ends abducts the ankle. If the comparison radiograph did not confirm reduction, longitudinal displacement is eliminated by a distraction force applied between the intermediate and distal basic rings (Fig. 2.5.15a). Displacement in the anteroposterior direction is eliminated by a stop with traction at the anterior end of the wire (Fig. 2.5.15b). If required, it is possible to increase the wire bending inwards (outwards) with its subsequent tensioning. It is necessary to pay special attention to accurate reconstruction of the fibula as it is the key to the ankle joint. To eliminate tibiofibular diastasis, the wire with a stop VIII,3-9 is inserted through the tibia. The ends of the wire inserted through the lateral malleolus (VIII,5-11) are bent inwards and tensioned at the same time (Fig. 2.5.16a). If the fibula was sound and the wire (VIII,5-11) was not inserted through the fibula, two wires are inserted: VIII,2-8(VIII,2-8) and (VIII,82)VIII,8-2. The distance between these wires, which are inserted parallel in opposite directions, must be 5–7 mm (Fig. 2.5.16b). It is necessary to remember that mutual compression of the third metatarsal in the syndesmosis area should not exceed 80–100 N [14]. It can be controlled by the mobility of the ankle joint with an amplitude of no less than 30/0/0. The posteroinferior (anteroinferior) part of the tibia can be reduced by directed pulling at the foot. In fractures of the posteroinferior part a wire is inserted through the calcaneal tuberosity, and in fractures of the anteroinferior part through the tarsal bones. The wire is tensioned in a half-ring connected to the device by threaded rods and axial distraction is applied. If no reduction is achieved by ligamentotaxis, reduction is performed in a similar manner to reduction of the lateral malleolus. A wire is inserted through the splinter parallel to the fracture plane. Its ends are bent down and fixed in the ring of the device. If required console posts can be used. The splinter is abducted by uniform tension of the ends of the wire. Figure 2.5.17 shows a variant of reduction wire fixation: directly into the basic support of the device. After reduction has been confirmed radiographically, final reduction and fixation of the splinter is performed by a wire with a stop. It is inserted outwards from the Achilles tendon through the splinter and the tibial bone. In the case of the posterior part, the wire is inserted from the back to the front and at an upward angle: IX,7-VIII,1. In fractures of the anteroinferior part of the tibial bone, wire IX,1-VIII,7 is inserted. The wire used to abduct, and the splinter is removed. The medial malleolus is adjusted using a thin awl or a single hook which is passed through the skin and brought to its top. In some cases complete alignment

of the fracture is hindered by the soft tissues. If this is the case, open reduction from the minimum approach is applied. The ankle is fixed by a wire with a stop. It is inserted from the side of the top of the ankle perpendicular to the fracture plane. The exit of the guiding end of the wire is usually on the posteroexternal aspect of the lower leg at the border of its middle and lower thirds. The wire is tensioned at this end and fixed with a traction clip to the middle ring of the device (Fig. 2.5.16a). The internal ankle can be fixed using a console wire with a stop. If comparison radiographs show residual incomplete dislocation of the foot outwards (inwards), this indicates absence of anatomical restoration of the ankle joint fork. The wire calc.,9-3 (or calc.,3-9) is inserted through the heel in the frontal plane. In the plane of the inserted wire a half-ring support is installed and connected by three rods with the distal basic support of the lower leg. Diastasis of 2–3 mm is created between the joint surfaces and by pulling at the guiding end of the wire the dislocation of the foot outwards (inwards) is eliminated. The orientation of the fragments of the external (internal) ankle is improved, and the tibiofibular diastasis is eliminated. If the foot is incompletely dislocated forwards or backwards, the wire calc.,3-9 without a stop is inserted. The ends of the wire are bent backwards or forwards in accordance with the foot displacement. Uniform tension of the ends of the wire results in transfer of the foot by the designated amount and elimination of the dislocation.In the case of a combined incomplete dislocation outwards and backwards, the foot is first moved inwards by means of a wire with a stop. The ends of the wire are then bent forwards and the residual incomplete dislocation is eliminated. Temporary immobilization of the ankle joint by means of an additional support on the heel bone is necessary in cases of injury to a deltoid ligament or the talofibular ligament,and in cases of incomplete dislocation of the foot forwards or backwards without fracture of the anteroinferior parts of the tibia. In other cases, it is sufficient to use an elastic foot support fixed to the device. Figure 2.5.18 shows other of fixation device variants that can be used for injuries of the ankle. In the device shown in Fig. 2.5.18a, instead of the proximal hybrid support V,12,120; VI,3-9, a support based on wires V,9-3; VI,2-8; VI,4-10 is used. However, this assembly based on one support (Fig. 2.5.18b) has limited abilities. In the case of an isolated rupture of the distal tibiofibular syndesmosis at level VIII, two wires with bending corkscrew-type stops are inserted from opposite directions. The ends of the wires are fixed in a two-thirds or three-quarter ring support. A half-pin is inserted at

2.5 Fractures of the Tibia and Fibula

a

b

a

Fig. 2.5.16a,b. Ilizarov external fixation device for fixation of pronation fracture-dislocations of the ankle

a

b

the higher level and fixed to the support. The wires are then tensioned in the opposite direction to eliminate the tibiofibular diastasis. The MUDEF designation of the device is as follows: VII,12,120; (VIII,8-2)VIII,8-2; VIII,2-8(VIII,2-8) Another algorithm can be used for the external fixation of the ankle joint. The first stage involves open reduction of the internal ankle and its fixation by a wire with a stop or a console wire. The minimum approach is used in this case involving only visual control and with the possibility of removing the tissues. This stage generally results in elimination of the incomplete dislocation of the foot outwards (inwards) and a better

187

b

Fig. 2.5.17a,b. External fixation device for reduction and fixation of the posteroinferior tibia (rear view)

Fig. 2.5.18a,b. CEF devices for fixation of fractures of the ankle

location of the fibula fragments. In addition, creation of an internal rest for the ankle bone prevents transfer of the external incomplete dislocation of the foot into an internal dislocation, which sometimes happens with the “traditional” method of reduction. A wire talus,9-3 with a stop is inserted through the ankle bone, parallel to the space of the ankle joint. The wire is inserted slightly to the front of the top of the external ankle. The wire is tensioned in the basic support of the device using posts. The next stage involves reduction and fixation of the anteroinferior part of the tibia. The radiographic monitoring of the degree of abduction of the splinter identifies the effectiveness of elimination of the in-

188

2 Specific Aspects of External Fixation

complete dislocation of the foot and the character of the displacement of the fibula fragments. The residual displacement of the foot is eliminated by pulling the guiding end of the wire and/or its arched bend forwards or backwards. If displacement of the fibula fragments still remains,it is eliminated in the way described above. It should be noted that use of arthroscopy facilitates reduction considerably. Cleansing of the joint with removal of small bone splinters and cartilage fragments is an important component of prevention of traumatic deforming arthrosis. If the operation involves use of arthroscopic devices, a device support is installed on the foot in all types of injuries and a distraction force is applied to increase the spacing of the ankle joint. External fixation in injuries of the ankle joint is completed by fixation of the anterior part of the foot by means of a foot support (Fig.1.10.1).The foot is fixed for 2.5–4 weeks,after which the wires are removed from the ankle (heel) bones.

2.5.5

Chronic Ankle Injuries

In the opinion of Oganesyan et al. [15] injuries of the ankle joint can be referred to as “chronic” when from 2 weeks to 1.5 months have passed since the injury, i.e. to the primary union of the fragments by membrane reticulated tissue. The methods of external fixation allow restoration (or improvement) of the anatomy of the ankle joint from 4 to 6 or more months since the injury. It should be noted that even if the decision was made to perform a reconstructive operation (arthrodesis, arthroplasty), the use of external fixation techniques allows restoration of the mechanical axis of the lower extremity as the first stage with minimum trauma. The operation starts with the installation of a basic transosseous module onto the lower leg that is based on two wire supports,I,2-8; I,4-10 — VI,2-8; VI,4-10, or on one combined, V,12,120; VI,9-3. Special attention must be paid to the orientation of the supports relative to the soft tissues. The module is placed perpendicular to the anatomical axis of the tibia so that the lower leg is located in the centre of the support located at level VI. In the case of a chronic incomplete dislocation of the foot outwards, the ring is placed inwards by the amount of the dislocation plus 2– 3 cm.Analogous methods are applied for other variants of foot displacement. Only then are the transosseous elements fixed to the support(s). Next, osteotomy of the ankle at the height of the deformity is performed with the minimum number of incisions. The line of the osteotomy of the lateral ankle must be made in the oblique direction for subsequent restoration of the

length of the fibula as its reconstruction is obligatory. An apposition suture is applied to the wounds. In the case of chronic rupture of the distal tibiofibular syndesmosis, that may further prevent elimination of the diastasis, the fibrous material is removed via a 5-mm incision with a Volkmann curette. The assistant then fixes the lower leg and the surgeon moves the foot in order to set it. A ring support is installed at level VIII and connected by three rods to the ring mounted at level VI. The foot is placed in the position 0/0/ and a wire with a corkscrew-like stop of diameter 5–8 mm is inserted through the centre of the ankle bone unit, parallel to its joint surface in the frontal plane. The more marked the osteoporosis, the larger the diameter of the stop. In cases of incomplete dislocation of the foot outwards the wire talus,9-3 is used. After that the wire calc.,3-9 is inserted through the heel bone perpendicular to its anatomical axis.The wire must be located parallel to the wire talus,9-3. A threequarter ring support is installed in the plane of the wire inserted through the heel bone and is connected by three rods to the support above. The distance from the internal edge of the distal three-quarter support on the heel must be sufficient to allow unhindered movement of the foot during setting of the dislocation. The wire inserted through the heel bone is tensioned and fixed to the three-quarter support. As the wires inserted through the ankle and heel bones are located one above the other, a slotted washer placed under the post is used for fixation of each end of the wire calc.,3-9.The wire inserted through the ankle bone is fixed via posts. The guiding end of the wire must be provided with a distraction clip. Thus, the wires inserted through the ankle and heel bones are fixed to the distal support of the device. The wire talus,9-3 is left untensioned at this stage. Over a period of 3–5 minutes a distraction force is gradually applied to increase the spacing of the ankle joint by 4–6 mm. Only then is the wire VIII,3-9 inserted through the tibial bone and fixed under tension to the support; in cases of internal incomplete dislocation of the foot, the wire VIII,9-3 is inserted. The incomplete dislocation of the foot is eliminated by traction on the wire with a stop inserted through the ankle bone. The wire inserted through the heel bone performs a double role: a guiding role and also allows maintenance of the diastasis between the joint surfaces (Fig. 2.5.19a). During setting, the foot is manipulated by hand. Elimination of the incomplete dislocation usually takes 5– 10 minutes of gradually increasing manipulations. In cases of incomplete dislocation of the foot forwards or backwards in the sagittal plane, the distal support is displaced in the necessary direction relative to the basic device (Figs. 1.6.4–1.6.8).

2.5 Fractures of the Tibia and Fibula

189

Fig. 2.5.19. External fixation devices for fixation of chronic injuries to the ankle joint (dislocation setting “inside the device”)

a

b 2

1

4

5

3

V,1,120; VI,9-3 —— VIII,3-9 ←→ talus,9-3; calc.,3-9 150

150

2

5

1

(a)

3/4 150

6

7

4

3

V,1,120; VI,9-3 —— VIII,3-9; (VIII,8-2)VIII,8-2; (IX,9,90) ←→ talus,9-3; calc.,3-9 (b) 150 150 3/4 150

Fig. 2.5.20a,b. Variant external fixation devices for fixation of injuries to the ankle. Fixation to the support of the half pin VIII,12,90 using the device shown in Figs. 1.2.2k and 1.4.10 allows easy elimination of the incomplete dislocation of the foot both in the frontal and sagittal planes (a). After reduction the proximal support can be removed (b)

a

b 1

2

5

3

4

5

3

4

II,8-2; II,4-10 —— VIII,12,90 ←→ calc,8-3; calc.,4-10 (a) 150 150 3/4 150 1

2

VI,2,120; VIII,12,90; (IX,9,90) ←→ calc,8-3; calc.,4-10 (b) 1/2 150 3/4 150

The use of the procedure described allows elimination of incomplete dislocations ofthe foot that occurred 3–4 or more months previously in a single step. If the comparison radiograph shows that there is residual dislocation, it is gradually eliminated during the postoper-

ative period. In this case, the manipulations described below are performed during the second stage of setting of the foot. If elimination of the incomplete dislocation of the foot is confirmed, open adaptation of the medial malleolus is performed and it is fixed by a wire with

190

2 Specific Aspects of External Fixation

1

3

2

8

4

9

VI,2-8; VI,10-4 —— VIII,3-9; VIII,4-10; (VIII,11-5); (IX,5-11) 150

150

5

6

7

←◦→ calc.,2-8; calc.,4-10; m/tars.,V–m/tars.,I oval 150

Fig. 2.5.21. External fixation device for fixation of chronic injuries to the ankle (dislocation reduction by mutual displacement of the transosseous modules)

a corkscrew-like stop. An anteroposterior radiograph is obtained to determine whether the lateral malleolus is shortened. If it is indeed found to be shortened, and “sliding”along the oblique osteotomy line does not correct the length, it is necessary to use free bone plasty of the diastasis. The proximal fragment of the fibula is fixed by a wire inserted through both bones of the lower leg: (VIII,8-2)VIII,8-2. The tibiofibular diastasis is eliminated by tensioning the wire. The ankle is stabilized by a wire inserted in a plane close to the sagittal plane: (IX,5-11). The lateral malleolus can be fixed by a console wire with a stop inserted in the frontal plane: (IX,9,90) (Fig. 2.5.19b). If not more than 6–8 weeks have passed since the injury, the location of the splinter of the anteroinferior or posteroinferior parts of the joint surface of the tibia is usually improved after setting of the foot. The residual displacement is eliminated by means of an arched bent wire, as described in the section devoted to issues of treatment of ankle fractures. After the reduction has been confirmed radiographically, the splinter is fixed

by a wire with a stop. It is inserted outside the Achilles tendon through the splinter and the tibia. In cases of a fracture of the posteroinferior part of the tibial bone the wire IX,7-VIII,1 is inserted; in cases of a fracture of the anteroinferior part, the wire IX,1-VIII,7 is inserted. The wire used for abduction of the splinter is removed. If the fragment has already fused in the wrong position, osteotomy, open reduction and fixation are performed. For a chronic injury of the ankle joint, it is possible to use the technique of mutual displacement of transosseous modules fixing the lower leg and the foot (Fig. 2.5.21). The operation starts with mounting of the basic device on the lower leg: VI,2-8; VI,10-4 — VIII,3-9; VIII,4-10. After that a support is installed on the lower leg (Fig. 2.5.13). Osteotomy of the ankles is performed with the minimum incisions along the line of the former fractures. A unit is mounted between the distal support of the lower leg and the support on the foot allowing a distraction force to be applied to move the foot in the necessary direction (Figs. 1.6.4–1.6.8). After setting of the dislocation the reduction and osteosynthesis ankle are performed following a method similar to that described above. Figure 2.5.20 shows, as an example, the method for eliminating a tibiofibular diastasis with the help of arched bending of wire (VIII,11-5), and reduction and fixation of the lateral malleolus by wire (IX,5-11). External fixation is completed by fixation of the anterior part of the foot with a foot support (Fig. 1.10.1). If the medial malleolus set 3–4 weeks after elimination of the incomplete dislocation of the foot, plasty of the deltoid ligament is performed.During osteosynthesis according to Fig. 2.5.18, a week prior to the intervention the wire is removed from the ankle bone. To stabilize the foot, an additional wire with a stop is simultaneously inserted through the heel bone: calc.,10-4. Analogous methods are used in cases of chronic injury of the ankle-fibula ligaments.

2.6

Compound Fractures

There are a number of criteria for selection of the external fixation technique in compound (open) fractures (Figs. 2.6.1–2.6.9), including gunshot wounds. Among them, the most important are the grade of damage to the bone (type “A”,“B” or “C” according to the AO/ASIF classification), the skin according to the IO scale, and the muscles and tendons according to the MT scale,and the grade of neurovascular damage according to the NV scale [1]. The degree of contamination and infection of the wound is also determined. In compound fractures with rupture of the skin from the inside (IO1) and up to 3–5 cm in size (IO2) or in presence of avulsion of the shoulder, forearm or

2.6 Compound Fractures

femur, with limited damage to the muscles of a single muscular group (MT2), and in the absence of neurovascular damage (NV1) during the primary surgical treatment, as a rule, the bone fragments need not be isolated. These injuries correspond to IA-IB compound fractures according to the classification of Kaplan [16]. The bone fragments are repositioned and fixed as in simple fractures following drainage and suturing of the wound. In gunshot fractures, primary surgical treatment is not indicated in multiple point wounds that contain no foreign bodies and are not accompanied by a growing haematoma or disorder of the peripheral circulation [17, 18]. The approach is different if the skin wound is over 5 cm long, if there are nonviable areas (IO3), if there is considerable contusion through the whole thickness of the skin, in graze wounds or if there are defects in the skin (IO4),if there is considerable damage to the muscles (MT3), if there are muscle defects or rupture of the tendons, or if there is extensive muscle contusion (MT4). These types of damage, according to the classification of Kaplan and Markova, correspond to the compound fractures IIA, IIB, IIIA, IIIB. The operation starts with installation of the basic supports. In injuries to the proximal or distal bone segments, the basic supports are mounted only on the longer bone fragment. When fixation of a joint is contemplated, the transosseous module is superimposed onto the adjacent segment. Sites of exit of the transosseous elements are covered with sterile drape and/or bandage. The margins of gunshot wounds, the exit aperture in particular, are widely dissected. Skin margins are dissected as economically as possible. The wound canal and the wound pockets are revised. If necessary, a decompression fasciotomy of damaged bone fascial sheaths is carried out, and obviously nonviable tissues are removed. With minimal damage, bone fragments are isolated preserving connections between the bone fragments and the soft tissues. Only small intensely contaminated bone fragments with no connection to soft tissues are removed. Free large fragments are treated and then placed in a saline solution of broad-spectrum antibiotics. During debridement, the wound is continually irrigated with antibiotic solution as a pulsed jet followed by active aspiration of the liquid. Additional prophylactic treatment against infectious complications is also carried according to the recommendations of Syzganov and Tkachenko (1958, cited in [19]), which includes ultrasonic cleansing of the wound, and infiltration of the surrounding tissue with a broad-spectrum antibiotic. Using the basic supports as “bone-holders”, the length and axis of the segment are restored with no repositioning or fixation of the bone fragments. This is

191

Fig. 2.6.1. Ilizarov method for replacement of a skin defect

necessary for determining whether it is possible to repair the damaged major vessels (if impossible replacing the defect with an autologous vein graft), nerves, muscles and tendons with simultaneous preservation of the anatomical length of the segment. If this is possible, then the next stage involves restoration of the damaged soft tissue structure. During this stage of the surgery, the basic supports are temporarily connected to two telescopic rods, and/or the main bone fragments are connected with the aid of diafixation with wires. If, due to artery injury, noncompensated ischaemia of the extremity is established, the main blood ﬂow should first be restored. Then, in compliance with the biomechanical requirements of the external fixation, the necessary number of intermediate reductionally fixing supports are installed. Under visual control, the main bone fragments and splinters are repositioned and then stabilized in the device by insertion of the reductionally fixing transosseous elements. For fixing splinters, as well

192

2 Specific Aspects of External Fixation

as conventional wires, console wires with a stop can be used. Because of the character of the bone and soft-tissue injuries, the selection of levels and positions for insertion of transosseous elements is limited in compound fractures. Therefore, as well as the reference positions, safe positions, which only avoid damage to the main vessels and nerves, may be used more widely. Further, in order to provide freedom of movement in the joints, some transosseous elements are better removed and new ones inserted using the reference positions. In a number of cases, in order to be able to restore the soft tissue structure without tension, including vessels and nerves, the adjacent joint should be placed in a position, for example with the lower leg bent, which can be maintained during the postoperative period,and which will allow the soft tissue to be removed afterwards, by installation of a transosseous module in the adjacent segment based on one or two external supports. This module, which is installed with the aid of hinges in compliance with the rotational axis of the knee or ankle joint, is connected with the basic device fixing the bone fragments (Figs. 2.3.18–2.3.20, 2.14.5, 2.14.18, 2.14.19, and 2.14.23).After repairing the vessels and nerves under microscopic control, the position of the joint is gradually changed to the zero position.After slight tension or“straightening”has been achieved [20], the hinges are stabilized. From the 14th to the 21st day, graded movement is started in the joint in the direction that will cause tensioning of the sutured soft-tissue structures. The distraction force applied with the aid of the swivel hinged section is selected such that the vessel and nerve stretching does not exceed 0.75–1 mm per day (three or four times by 0.25 mm). Later, the hinge subsystem is used, when necessary, for passive–active development of movement in the joint. The above procedure generally enables one to repair damaged soft tissues, providing the defect is less than 50–55 mm. In those cases when, after modelling the length and segment axis restoration, the diastasis remains or considerable tension of the damaged soft tissues is required, there is wide segmented damage to the vessels and nerves (NV4),and there is no possibility of performing plastic repair of the defect, the following method can be used. The bone fragments are repositioned and stabilized in the device supports. From medical records and photographs the positions of the external supports and transosseous elements by which the repositioning was achieved are noted. The fragments are then given an “atypical” position which allows suturing of the soft tissues without tension. These could be angular, rotational deformities, or lateral or longitudinal displacement of the fragments. The possibility of development of a trophic disorder as a result of crimping or excessive bending of major vessels

should be born in mind. The modules of the proximal and distal bone fragments are stabilized in this newly achieved position. This technique enables one to carry out a suture repair or a plastic repair of the damaged soft-tissue structures, and to secure the skin without any tension. Combining the methods of fixation of the adjacent joint in the desired position and rendering the fragments into an atypical position will make it possible to reduce the degree of deformity of the damaged segment. The operation is terminated with repeated abundant washing of the wound with antiseptic solution, followed by the establishment of a system of ﬂowing drainage. It is necessary to cover the bone fragments with soft tissue. Skin autografts or allografts or artificial skin are used to repair defects. In gunshot fractures, particularly those caused by modern weapons, suturing of the primary wound cannot be recommended. The method of choice is the method of Ilizarov which involves replacing the skin of the defect. In each margin of the wound, a Kirschner wire is inserted and then fixed with pulling and distraction clamps to the device supports (Fig. 2.6.1). In the postoperative period, the wound margins are gradually approximated (0.25 mm three or four times a day) until they can be stitched together. In extensive skin defects, vascularized full-layer autografts should be considered. Because of the relatively high traumatic character of such an intervention, particular attention should be paid to the preoperative preparation. When, during the debridement, bone defects occur in a segment, the assembly of the transosseous device must provide for the possibility of restoring the lost tissue. For this purpose, the monolocal and bilocal methods of external fixation can be used [21, 22]. The ends of the fragments during the debridement must be processed for their adaptation, if need be. In monolocal distraction osteosynthesis, the proximal and distal bone fragments are simultaneously approximated until in close contact. Within 14–18 days, the bone fragments are gradually separated at a mean rate of 0.25 mm three or four times a day until the segment length is restored (Figs. 2.6.2b, c and 2.6.3b, c). If the fibula hinders the approximation of the fragments of the femur, one should resort to its osteotomy or segment removal. In the forearm, the monolocal method of distraction osteosynthesis can be only used if the two bones show similar defects. In some cases, the simultaneous approximation of the main bone fragments is impossible. The most frequent cause of this is evident crimping of the soft tissues resulting in trophic disorders and hindering wound suturing. In these cases, monolocal successive compression-distraction osteosynthesis is used. For

2.6 Compound Fractures

a

b 1

2

3

193

c

6

5

4

I,8,90; II,11,90; II,9,90 →← V,8,90 —— VII,8,120; VIII,3-9 (a) 1/3 210 195 3/4 180 I,8,90; II,11,90; II,9,90 ←→ V,8,90 —— VII,8,120; VIII,3-9 (b) 1/3 210 195 3/4 180 I,8,90; II,11,90; II,9,90 —— VI,9-3 —— VII,8,120; VIII,3-9 (c) 1/3 210 195 3/4 180

a

b 1

2

4

c

3

I,11,90; II,8,90 →← V —— VII,8,120; VIII,3-9 1/2 160

1

140

3/4 140

2

4

1

140

2

3/4 140

5

(a)

3

I,11,90; II,8,90 ←→ V —— VII,8,120; VIII,3-9 1/2 160

Fig. 2.6.2a–c. Examples of open monolocal distraction (b → c) and alternating compression-distraction (a → b → c) for external fixation of segmented defects of the femur

4

3

(b)

I,11,90; II,8,90 —— V,4-10 —— VII,8,120; VIII,3-9 (c) 1/2 160 140 3/4 140

Fig. 2.6.3a–c. Examples of open monolocal-distraction (b → c) and alternating compression-distraction (a → b → c) for external fixation of segmented defects of the humerus

194

2 Specific Aspects of External Fixation

Fig. 2.6.5. After corticotomy, one or two stitches are placed into the wound. A cutaneous circular bandage should not be used. To reduce the volume haematoma, a compression sling-like bandage is applied. Five to eight layers of sterile fabric dressing are applied to the wound area and are fixed with bandage wound tightly on half-pins mounted on the device. A specially prepared small elastic sling with fixing hooks can also be used [24]

Fig. 2.6.4. Ilizarov method of corticotomy

this purpose the bone fragments are gradually approximated after the skin wound has healed. The rate of approximation is limited by the presence of a neurotrophic disorder and usually does not exceed 3–5 mm per day in four to six sessions. After approximation of the bone fragments, they are compressed axially or laterally, depending on the plane of the bone wound. In 14–18 days, the bone fragments are gradually separated at a mean rate 0.25 mm three or four times a day until the segment length is restored (Figs. 2.6.2 and 2.6.3). If by the end of the distraction period, signs of tension of the soft tissues appear, the tension caused by the transosseous elements fixed in the reductionally fixing supports, they should be replaced. For example, in Fig. 2.6.2, half-pin V,8,90 is replaced with wire VI,9-3. Segmental defects up to 45–50 mm of the humerus and femur can be restored, and defects of a single forearm bone can also be restored by elongation of one fragment – usually the longer one [23]. The same method must be used when there are signs of reducing revascularization of the main fragment ends, e.g. in the presence of free autografts (i.e. bone fragments with circulation failure). For elongation of a bone fragment, corticotomy together with osteoclasis are performed. The rods connecting the device supports proximal and distal to the contemplated corticotomy area are disassembled, i.e. the modules by which the proximal and distal bone fragments are to be fixed are moved apart. Following this, through an incision, the adjacent and lateral cortical plates are dissected with a narrow 5-mm osteotome (Figs. 2.6.4 and 2.6.5). The proximal and distal modules are rotated manually in opposite directions to fracture the remaining part of the cortical plate. In the Russian Ilizarov Research Center this type of bone destruction

has been proved to result in the formation of a distraction regenerate.The threaded rods are reinstalled in the apertures from where they were removed. Elongation can involve only one of the bone fragments when there is a thin “icicle-shaped” form at one end of the fragment. It can be inserted into the bone marrow canal of the opposite fragment, and the shortening will be compensated for by formation of a distraction regenerate at another level. Among the intermediate (movable) fragment variants presented in Fig. 2.6.6 (“cross-wire bone transport”), fixation with the transosseous elements in an external support is the most rigid. This condition is the most beneficial for the formation of the distraction regenerate. One should keep in mind that in this way relocation of a fragment by an average of 30–50 mm is possible, depending on the segment and condition of the soft tissues. If a half-pin cuts through soft tissues, inﬂammation of the soft tissues starts around the transosseous elements. In order to reduce the risk of such a complication, prior to insertion of the transosseous elements, the soft tissues are shifted aside with a finger or a small hook to the place where the distraction regenerate will later form. If the bone needs to be moved a greater distance, then during the debridement one should insert the axial wire (Fig. 2.6.6d) or ﬂexible pulls (Fig. 2.6.6e, f). When the relocating support has reached its limit of movement the transosseous elements fixed in it are removed. Further relocation of the fragment is performed with the axial wire (or ﬂexible pulls). Traction-guiding wires (Fig. 2.6.6c) are inserted immediately before removal of the transosseous elements of the intermediate support. In order to determine the magnitude of the traction to be applied to the traction-guiding wires to enable linear relocation of the intermediate bone fragment by 1 mm, it is necessary to perform calculations using a radiograph [4, 25, 26].

2.6 Compound Fractures

a

b

c

d

e

f

195

Fig. 2.6.6a–f. Main variants for the relocation of intermediate fragments in an external fixation device (“bone transport”). a, b With the aid of transosseous elements fixed to the external support. c With the aid of traction guiding wires. d With the aid of an axial wire. e With the aid of a pulled wire. f Technique of M. Weber. Variant b is different in principle from variant a in that the sector with the half-pins is an independent module that is installed in the preliminarily assembled device. In Weber’s technique (f), contrary to the pulled wire (e), thin flexible stranded cables are used together with roller units in the traction device

196

2 Specific Aspects of External Fixation

a

b

c 1

2

3

6

7

4

5

I,8,120; II,11,90; II,9,90 ←→ III,10,120; IV,8,90 →← VII,8,120; VIII,3-9 1/3 225

3/4 195

8

3/4 180

9

I,8,120; II,11,90; II,9,90 ←→ V,3,130; V,9,130 →← VII,8,120; VIII,3-9 3/4 195

1/3 225

11

(a)

3/4 180

(b)

10

I,8,120; II,11,90; II,9,90 ←→ V,8,120; VI,9-3 →← VII,8,120; VIII,3-9; VIII,4,90 (c) 3/4 195 1/3 225 3/4 180

Fig. 2.6.7a–c. Scheme of the bilocal compression-distraction osteosynthesis in segmented defect of the femur

2.6 Compound Fractures

a 1

2

3

b

6

7

5

c

4

I,4-10; I,5,90(I,5,90); (II,9,90) ←→ (III,9,90); (IV,12,70) →← (VII,10,120) VIII,6-12(VIII,6-12) (a) 3/4 120 120 120 I,4-10; I,5,90(I,5,90); (II,9,90) —— V —— (VII,10,120); VIII,6-12(VIII,6-12) 3/4 120

120

120

(b)

I,4-10; I,5,90(I,5,90); (II,9,90) ←→ (V,2-8); (VI,11,70) →← (VII,10,120); VIII,6-12(VIII,6-12) (c) 3/4 120 120 120

Fig. 2.6.8a–c. Devices for replacement of defects of radial segments by elongation of the proximal fragment

Fig. 2.6.9. Replacement of tibial defects by the method of A.P. Barabash

197

198

2 Specific Aspects of External Fixation

In bilocal distraction-compression transosseous osteosynthesis, the transport of the intermediate bone fragment is started on the 5th to the 7th day. The average rate of movement is 0.25 mm four times a day. One should try to join the fragments as soon as possible and to provide conditions for their joining. Therefore, simultaneously with the distraction (for formation of the regenerate), the opposite bone fragment should be approximated to the relocated fragment. The approximation rates are limited by the crimping of the soft tissues and the appearance of subsequent neurotrophic disorders. In osteosynthesis of the lower leg, the approximation of the fragments could be hindered by the fibula. Osteotomy or removal might be necessary. After contact of the fragments has been achieved, the device is again partially reassembled. Transosseous elements will again be inserted through the relocated fragments and fixed to the external support, an the distraction-guiding half-pins (axial wires, wire pulls) are removed. At the docking site counter compression is applied. Poor adaptation of the ends of the bone fragments or avascularity in the ends are indications for their open reduction or for bone grafting. The formation of the distraction regenerate is not terminated until the discrepancy in the lengths of the extremities is eliminated. Figures 2.6.7 and 2.6.8 show examples of bone segment defect replacement by elongation of the proximal fragment. Replacement of segment defects of over 5–7 cm (over 12–15% of the bone length) by polylocal osteosynthesis is discussed in section 2.10. In the case of a marginal defect triangular in shape, the segment will be given an angular deformity until fragment wound surfaces are in contact. The transosseous modules fixing every bone fragment are connected with two axial and one swivel hinge. On the 7th to 10th day after the operation, gradual distraction is started to provide an average movement of 0.25 mm three or four times a day in order to form a triangular regenerate. For simultaneous elongation, a trapezoidal regenerate is formed. More details of the formation of the wedge-shaped distraction regenerate are presented in sections dedicated to traumatic deformities, and the transosseous osteosynthesis of pseudoarthroses. In Fig. 2.6.9, one of the variants for replacing a longbone defect by means of dosed rotation and bringing down the intermediate fragment is shown.

2.7

Malunited Fractures

When bone fragments unite in the wrong position (Figs. 2.7.1–2.7.4), the advantages of external fixation in relation to the possibility of gradual elimination of

soft-tissue retraction,and the preservation of interfragmentary regenerate are clear. Depending on the degree of maturity, mechanical stability, and kind of fragment displacement, various frame configurations and rates of repositioning are used. If no more than 2 or 3 weeks has passed from the time of fracture (about 7 to 10 days for metaphyseal and metadiaphyseal fractures), and one-stage repositioning is complicated by retraction of muscles, accelerated repositioning is indicated using an external fixation technique. The operation is conveniently carried out under conditions of skeletal traction on an orthopaedic table. Devices configurations are similar to those recommended for emergency fractures at the same location. Reductionally fixing wires are fixed to the external support not with traction clips rather than with bolts. Half-pins can be used for elimination of residual displacement of bone fragments by pushing or pulling. It is necessary to keep in mind that one-stage forced traction can cause neurotrophic problems and the formation of contractures. Therefore the distraction force is applied on the operating table only within the limits of moderate elastic tension of soft tissues.Thus longitudinal displacement of fragments is usually eliminated by no more than 10–15 mm in one stage, and angular deformation by no more than 25–35◦.All other types of residual displacement should be eliminated gradually. Distraction is started at 3–5 days to provide movement of 1.5–2 mm a day six to eight times. Indications to reduce the movements and increase their frequency are the occurrence of neurotrophic problems that result in a painful syndrome. Correct (perpendicular to the anatomical axis of the fragments) installation of device supports promotes “automatic” improvement of the arrangement of bone fragments. Using reductionally fixing transosseous elements (Figs.1.6.9 and 1.6.10) or mutual displacement of the modules fixing the bone fragments (Figs. 1.6.4–1.6.8) achieves final reduction of the bone fragments. If the fracture occurred 4–6 weeks previously (2–3 weeks for metaphyseal fractures) the bone fragments have usually become united and the soft tissues have retracted. The tasks of external fixation in this case are repositioning of the bone fragments by transformation of interfragmental regenerate by distraction and measures to prevent neurotrophic impingement which can arise during accelerated reduction. Frame configurations are similar to those recommended for fractures in emergency setting. However, during the first stage, as a rule, only basic transosseous elements are inserted. In stable angular bone fragment deformation, the basic supports of the conventional Ilizarov assembly should not be placed perpendicular to the anatomical

2.7 Malunited Fractures

199

Fig. 2.7.1. Osteotomy of the fibula is better performed in the distal third because in this location it is more easy technically and less traumatic. A longitudinal anterolateral skin incision of 7–10 mm is made towards the anterior surface of the fibula. A periosteal elevator is used for separation of the soft tissue and periosteum, and for the introduction of the osteotomy instrument. Osteotomy is carried out with the soft tissue protected by the protector (a frame clamp) at a distance from the skin equal to the diameter of fibula. Osteotomy of the fibula is achieved by two or three impacts of a hammer. This procedure avoids damage to interfragmentary vessels

a

b 1

c 3

2

4

(I,8-2)I,8-2; I,4-10 —— III ←→ V —— (VIII,8-2)VIII,8-2; VIII,4-10 150

150

150

5

150

(a)

6

(I,8-2)I,8-2; I,4-10 —— III,3-9 —— V,9-3 —— (VIII,8-2)VIII,8-2; VIII,4-10 (b) 150 150 150 150 7

8

II,1,120; III,3-9 →← V,9-3; VII,12,70 1/2 150

1/2 150

(c)

Fig. 2.7.2a–c. External fixation devices for fixation of malunited fractures of the tibia. Modular transformation of the device (c) is the method of a choice, bearing in mind that this technique requires that the joints of the half-rings of the reductionally fixing supports be positioned in the frontal plane

200

2 Specific Aspects of External Fixation

a

b 1

c

2

II,5-11 —— IV ←→ VI —— VIII,9-3 1/2 150

140

1

140

(a)

3/4 140

3

4

2

II,5-11 —— IV,8,90 —— VI,8,90 —— VIII,9-3 (b) 1/2 150 140 140 3/4 140 5

3

4

2

140

3/4 140

III,11,120; IV,8,90 →← VI,8,90 —— VIII,9-3 140

a

Fig. 2.7.3a–c. Devices for the stepwise reduction of malunited humerus fractures. In osteoporosis the basic supports should have two basic wires

(c)

b 2

1

c

3

5

4

I,4-10; I,5,90(I,5,90); (II,9,90) —— III ←→ V —— (VII,10,120); (VIII,7-1) 3/4 120

120

120

(a)

120 7

6

I,4-10; I,5,90(I,5,90); (II,9,90) —— III ←→ V —— VII,8,120; (VII,10,120); VIII,6-12(VIII,6-12) (b) 3/4 120 120 120 120 9

8

11

10

I,4-10; I,5,90(I,5,90) —— III,8,90; (IV,10,90) →← V,8,6,90; (V,11,90) —— VIII,6-12(VIII,6-12) 3/4 120

120

120

120

(c)

Fig. 2.7.4a–c. In the treatment of malunited forearm bone fractures, restoration of the relationships in the radioulnar joint is especially important for the subsequent function of a segment. As an example, the stages of treatment of a malunited forearm bone fracture with primary shortening of the radius is shown. As can be seen, at each stage of reconstruction the method demands the insertion of additional transosseous elements and the removal of wires and half-pins that have performed their task

2.8 Basic Principles of Correction of Long-Bone Deformities

axis of the bone fragment, but with 5–7◦ of hypercorrection. A basic wire support allows the connection of modules that fix both bone fragments using threaded rods due to elastic deformation of the wires. It is necessary to take into account that the use of pins in the basic support allows connection of transosseous modules,fixing the proximal and distal bone fragments with the use of hinges. Reduction by mutual movements of the intermediate (reductionally fixing) support and the modules fixing each bone fragment (Figs. 1.6.4–1.6.8) can be used for elimination of any component of deformation. These procedures, as a rule, are complementary to the basic approach. They complement the opportunities for repositioning with the help of reductionally fixing transosseous elements (Figs. 1.6.9 and 1.6.10). First, longitudinal displacement is eliminated. The rate of distraction should be on average 1.0–1.5 mm (0.25 mm four to six times a day). Usually simultaneously with elimination of shortening,angular deformation decreases as well. Reductionally fixing transosseous elements should be inserted after the creation of a diastasis between the bone fragments of up to 3–5 mm. Using these elements, transverse and residual angular displacements of the fragments are corrected gradually. Any rotational deformity is eliminated as a last step in deformity correction, after which the diastasis between the bone fragments is eliminated. If more than 6–8 weeks has passed since the fracture there is minimal mobility between the bone fragments (the fragments have become united). In this case closed transformation of regenerate requires significant distractional effort. Loosening of callus by wire drilling or partial corticotomy can provide successful closed bone fragment reduction. Correction of deformity should be carried out at a rate not exceeding 0.75 mm per day (0.25 mm three times per day). In patients of this group gradual bone fragment repositioning by mutual movement of transosseous modules fixing each bone fragment is more often used (Figs. 1.6.4–1.6.8). For each stage of repositioning (elimination of longitudinal, angular, peripheral and twisting displacement) a unified reductional node can be used. With increasing experience in the use of external fixation some stages of repositioning can be carried out together using combined repositioning units. The most effective are hinge-distractional subsystems. A detailed description of the use of Ilizarov hinges is provided in section 2.8 on external fixation of deformations. Large bone splinters are repositioned by means of wires with a stop and/or bent wires. They can be inserted transcortically or paracortically to a bone splinter. The method of Shved et al. [27] can also be

201

used (Fig. 1.6.13). When the splinter is located in an interbone space or near main vessels and nerves, a fork-shaped half-pin is recommended for repositioning (Figs. 1.4.8 and 1.6.14).

2.8 Basic Principles of Correction of Long-Bone Deformities In contrast to deformities of the long bones of the arm (see section 2.8.1), restoration of the mechanical axis of the lower extremities (Figs. 2.8.1–2.8.27) is an essential element of the reparative plastic operation, because the physiology of joint loading and gait mechanics depend on it. Elimination of the deformity should be preceded by treatment aimed at the restoration (improvement) of the functions of the joints adjacent to the segment. This aspect is discussed in section 2.14 on the treatment of contractures. The principles of correction of basic deformities are discussed in the following sections.

2.8.1 Inequality in Length of the Extremities Shortening of bone is considered as a type of deformity. Inequality in the length of the legs of up to 1.5 cm is not an absolute indication for surgical correction because it can be adequately compensated for by means of orthopaedic inserts into footwear or by adding height to the heels. The problem of lengthening the femur in accordance with the anatomical or mechanical axis is solved individually (Figs. 2.8.1–2.8.4). When lengthening the lower leg, this is not a consideration, because the anatomical and mechanical axes of the bones of the lower leg are parallel. Corticotomy with osteoclasis (Fig. 2.7.1) for lengthening the femur (or lower leg) is carried out outside the zone of the former fracture and, as a rule, a longer fragment. However, one should bear in mind that the nearer to the joint the lengthening is performed, the higher is the danger of developing contracture in that joint. Therefore, if there is a restriction in movement of the knee joint, the distraction regenerate on the femur should be formed over the length of the proximal/central two-thirds of the segment (from level II to level V). Lengthening the lower leg should be approached in a similar way if there is contracture of the ankle joint etc. An external fixation device assembly for the monolocal lengthening of the femur is shown in Fig. 2.6.2.

202

a

2 Specific Aspects of External Fixation

b

c

d

For lengthening the femur and lower leg at the level of the proximal third of the segment using the Ilizarov apparatus, the orientation of the proximal basic support after placement of the wires deserves particular attention [24, 30]. The plane of the proximal basic support ring on the femur should be at an angle of 100–110◦ to the femur axis, open to outside. This is necessary for correction of the varus deformity of the femur during distraction. The proximal basic support ring on the lower leg is placed to prevent recurvation valgus deformity, at an angle of 100– 110◦ , open to the inside and forward. Only then are the wires mounted in the support. Then, using elastic deformation of the wires, the proximal basic support is oriented parallel to the transosseous module, which will fix the distal fragment after corticotomy, and they are connected. Basic supports based on half-pins are placed perpendicular to the longitudinal axis of the bone. Lengthening the segment by more than 5 cm should be performed with the help of polylocal distraction osteosynthesis (Figs. 2.8.5 and 2.8.6). The rate of distraction lengthening at the level of the proximal corticotomy should be on average 0.25 mm three or four times a day. On the distal level of

Fig.2.8.1a–d. Mechanical (a, b) and anatomical (c, d) axes of the femur and tibia [28, 29]. It will be recalled that the mechanical axis of the lower extremity is a straight line, joining the centres of the femoral head, the knee and the ankle joint (a, b). In contrast to the mechanical axis, the anatomical axis of each long bone is the central diaphyseal line (c, d). As a synonym for “anatomical axis” one can use the term “longitudinal axis” (of bone, fragment). In the frontal plane, the mechanical and anatomical axes of the femur make an angle of 7±2◦ . In the sagittal plane, the anatomical axis of the femur is a curved line, which intersects the mechanical axis approximately at the level of the middle third of the segment. In the tibia, the mechanical and anatomical axes are parallel to each other. In the frontal plane, the anatomical axis of the tibia is located somewhat inside the mechanical axis, and in the sagittal plane anteriad to it

lengthening, to prevent formation of hypoplastic distraction regenerate,distraction is carried out at the rate of 0.25 mm two or three times a day. Another approach to eliminating inequality in the lengths of the extremities is to shorten the intact extremity. Establishment of good function of the extremity shortened because of trauma before the operation guarantees that the approach of the muscle attachment points on the sound leg will ensure good function in terms of support and movement after shortening. When shortening the femur, it is necessary to prevent deviation of the lower leg from the mechanical axis by correcting the lateral displacement of fragments. Device assemblies are similar to those recommended for the fixation of fractures. Anatomic axes of fragments are disposed parallel. Figure 2.8.7 shows the importance of correcting the peripheral displacement of fragments so that the mechanical axis of the lower extremity can be restored. To eliminate this kind of deformity, each bone fragment is fixed with a transosseous module, without connecting them. Osteotomy is carried out and, if necessary, the fragments are openly adapted with singlestage restoration of the extremity axis. Then, the transosseous modules are connected in the new state.When

2.8 Basic Principles of Correction of Long-Bone Deformities

a

b

203

c

Fig. 2.8.2a–c. When planning reconstructive operations, it is necessary to consider the orientation of the articular surfaces of the femur and tibia relative to the mechanical (a) and anatomic axes (b, c)

Fig. 2.8.3. Relationship between the shortening of the femur and deviation of the extremity from the mechanical axis. The greater is the shortening of the femur along the anatomic axis (e.g. in the event of union of fragments after a fracture resulting in a bone defect), the more significant is the extremity deviation from the mechanical axis. Thus, in traumatic shortenings, the bone is lengthened along its anatomic axis

204

a

2 Specific Aspects of External Fixation

b

c

Fig. 2.8.4a–c. In some inborn pathologies that require aesthetic surgery to increase the height, the mechanical axis of the extremity is retained (a). In these cases, lengthening of the femur along its anatomic axis will result in deviation of the lower leg from the mechanical axis (b). And the greater is the lengthening, the more pronounced will be this deviation. Therefore, in such cases, the femur is lengthened along its mechanical axis (c). Accordingly, transosseous modules, which will fix the proximal and distal bone fragments after corticotomy, are arranged perpendicular to the mechanical axis of the extremity

it is impossible to displace fragments in one step, e.g. in patients with at risk of necrosis with scarred and bone-connected soft tissues, the transosseous modules are displaced gradually in a reciprocal manner (Fig. 1.6.4).

2.8.2

Angular Deformities

This is one of the most complicated types of deformity from the point of view of the specific features of the external device assembly. For angular and rotational deformities a special term (proposed by Dr.Yasui from Osaka, Japan) is used: “centre of rotation of angulation”(CORA) [29].For similar situations, the Russian scientific literature uses the term “apex of deformation”. Both terms are used synonymously in this book because there is no semantic difference between them (Fig. 2.8.10). In the German literature, the term “fulcrum” is often used.

When the fragments of fibula have united at the angle, with no visually apparent deformity (usually up to 30–35◦ ), osteotomy is performed in the lower third of the diaphysis, because it is more simple technically and less traumatic. If pronounced curvature is present the bone is cut at the level of the deformity. Angular deformity of the femur or bones of the lower leg can be corrected with a one-stage operation and gradually over time. It should be remembered that the elongation of great vessels and nerves of the lower extremity, which are in a state of retraction and/or surrounded by scarred tissues, by more than 8–10 mm in one step is dangerous because it carries the risk of neurotrophic disturbance. To determine the maximum increase in length that can be achieved in one step after removal of the angular deformity, radiographs or a special calculation are used [29]. By convention, deformities up to 30–35◦ can be considered for one-stage axis restoration. To correct angular deformities of greater

2.8 Basic Principles of Correction of Long-Bone Deformities

205

Fig. 2.8.5a,b. Schemes for Ilizarov bilocal distraction osteosynthesis [24]

a

b 1

2

3

4

8

9

5

6

7

I,6-12; I,11-5; II,11-5; II,6-12 ←→ IV,1-7; IV,6-12 ←→ VII,3-9; VIII,8-2; VIII,4-10 arc 210

1

arc 210

2

3

8

4

(a)

180

9

5

7

6

(I,8-2)I,8-2; I,4-10; I,9-3; II,3-9 ←→ (IV,8-2)IV,8-2; IV,4-10 ←→ VII,3-9; (VIII,8-2)VIII,8-2; VIII,4-10 150

150

150

(b)

Fig. 2.8.6a,b. Schemes for bilocal distraction osteosynthesis with CEF

a

b 1

2

3

6

7

5

4

I,8,120; I,11,90; II,9,90 ←→ IV,10,120; V,8,90 ←→ VII,8,120; VIII,3-9 1/3 225

1

3/4 195

2

3

6

(a)

3/4 180

7

5

4

(I,8-2)I,8-2; I,4-10; II,1,90 ←→ IV,12,120; V,3-9 ←→ VII,12,90; (VIII,8-2)VII,8-2 (b) 3/4 150 150 150

206

2 Specific Aspects of External Fixation

Fig. 2.8.7a,b. Relationship between lateral fragment displacement and the mechanical axis of an extremity

a

b

Fig. 2.8.8a,b. Restoration of the mechanical axis of an extremity with a laterally displaced fragment. In practice, there are situations when it is impossible to perform corrective osteotomy at the level of the deformity or this is undesirable because of the presence of an osteomyelitic cavity, foreign body, pronounced scarring or other reasons. Performing osteotomy in the intact zone and restoring the mechanical axis of the extremity is a possible approach. Restoration of the mechanical axis of the extremity by osteotomy below the level of the deformity level is shown. It should be noted that given the initial movement limitation in the knee joint, it is advisable to perform such reconstruction above the level of the deformity

a

b

2.8 Basic Principles of Correction of Long-Bone Deformities

207

Fig. 2.8.9a–c. The degree of deviation of the extremity from the mechanical axis depends on the apex of deformation level

a

b

angles in one step, it is necessary to make several cuts over the wedge or to reposition the adjacent joints, thus decreasing the tension in great vessels and nerves. The operation started with mounting a transosseous module above and below the apex of the deformity. The modules are assembled with due regard for preoperative planning on the basis of the “Principles of Frame Construction” (section 1.11). Assemblies recommended for the external fixation of fractures of the femur and bones of the lower extremity can be used as a basis. Thus, the device for external fixation can include one or two external supports in each transosseous module. In order to place external supports perpendicular to the longitudinal axis of the bone fragment, corresponding control radiographs with labels are obtained. In one-stage correction of angular deformity, the adjacent and lateral cortical plates are destroyed through a 5-mm incision from the projecting side of the curvature using a narrow corticotome. Each passage of the osteotome through the cortical plate is finished by “kneading” movements (upwards–downwards) of the osteotome. Then, using assembled external supports, ﬂexion or rotational osteoclasis of the remaining cortical plate is performed. In the presence of osteosclerosis or deformities exceeding 15–20◦ this method of osteotomy is not always appropriate, and removal of a

c

wedge of bone is preferred (Fig. 2.8.12a). When there are great vessels and nerves, or scars, which can change the soft-tissue topography, in the osteotomy level projection, this stage of the operation is performed under visual control. After the one-stage restoration of the bone axis, the modules of each bone fragment are connected by half-pins and a compressive force is applied. When after one-stage removal of the angular deformity, significant shortening of the segment remains, distraction is started in 5–7 days with a lengthening of 0.25 mm three or four times a day until the inequality in the length of the extremities is eliminated. For gradual removal of an angular deformity by regenerate formation, external fixation is also started with the installation of transosseous modules above and below the apex of the deformity.Then the two modules are connected by a pair of axial hinges, located diametrically opposite and symmetrically relative to the bone (Figs. 2.8.15–2.8.20). The coaxiality of the mounting of each device module and of the hinges is confirmed radiographically. If open osteotomy is performed, the hinges are mounted under visual control. During osteotomy, the hinges are temporarily disconnected. In 5–7 days gradual discrete distraction is started, using the swivel hinge so that the distance between the opening cortical plates on the concave side of the bone

208

a

2 Specific Aspects of External Fixation

b

c

Fig. 2.8.10a–c. It is advisable to perform corrective osteotomy at the apex of deformation level (i.e. CORA): at the intersection of the anatomic (or mechanical) axes of the proximal and distal fragments (a). If, as well as angular displacement, the fragments have fused in a position of lateral displacement (b) or lateral and longitudinal displacement (c), the apex of deformation will be at some distance from the contact zone of the basic fragments

a

b

c

Fig. 2.8.11a–c. To restore the mechanical axis of an extremity with osteotomy outside the apex of the angular deformity, it is necessary to additionally displace fragments laterally. The need for this reconstruction procedure does not depend on performing osteotomy above (b) or below (c) the apex of deformity. The greater is the extent of the angular deformity and the further from its apex osteotomy is performed, the greater will be the magnitude of the fragment displacement laterally required to restore the mechanical axis of the leg. Therefore, the use of such an approach to reconstruction is limited by the extent of the correction required which should not involve fragment displacement by more than one-third to one-half of the bone diameter

2.8 Basic Principles of Correction of Long-Bone Deformities

is increased by 0.25 mm four times a day on average. It should be born in mind that the degree of separation of the cortical plates does not correspond to the displacement of (each) rod of the swivel hinge in the external supports (Fig. 2.8.17). If after removal of the angular deformity shortening of the segment remains, the hinges are replaced by connecting rods. If there is excessive tension, the soft tissue around exit sites of the basic supports inserted in the immediate vicinity of the osteotomy level is cut and the basic supports are removed. Distraction is performed such that the length is increased at the rate of 0.25 mm four times a day on average to eliminate the inequality in length of the extremities. Then the reductionally fixing transosseous elements are placed again to correct the position and stabilize the bone fragments. This method for correction of complicated deformities (angular or shortening) is the first step in the formation of a triangular regenerate and then with even distraction this regenerate is transformed into regenerate of trapezoidal shape. An alternative to the formation of distraction regenerate of trapezoidal shape is correction of angular deformity and lengthening of the segment at different levels. The versions of external fixation in patients with traumatic angular deformity of the femur with segment shortening serve as an example (Figs.2.8.21 and 2.8.22).

2.8.3

Rotational Deformities

Rotation deformity is corrected by one of the known methods of external fixation (Figs. 1.6.8 and 1.6.12). When the distal fragment is rotated after osteotomy in one stage, rods are mounted at an angle, connected to the supports, or transosseous elements are displaced in the supports of the distal external device. All other versions presented in the figures are suitable for gradual correction of the deformity. Thus, in patients with deformities of the femur and lower leg, as a rule reduction is achieved using reciprocal displacement of the transosseous modules fixing each bone fragment. Each stage of the correction of a complex deformity (elimination of shortening, angular deformity, peripheral displacement, rotational deformity) requires a uniform subsystem, which is fixed with partial reassembly of the device. As experience is gained in the use of external fixation, it is possible to combine some of the stages of transfer of fragments using combined reduction units. Devices with passive computer navigation, such as the Taylor spatial frame, the SUV-frame and the Poli Hex frame (Fig. 1.2.2p–r), have been developed and used for 10 years. They allow all components of deformation to be corrected in one step. However, it is necessary to remember that these devices cannot be

209

used in every situation. Therefore an orthopaedic surgeon must understand and be able to use the “classic” Ilizarov method of deformity correction. Recently the two-stage treatment of deformities has been developed. This method includes elimination of the deformity components using the techniques of external fixation, and then stabilization of the fragments with an implant [29,31,32].Lengthening of the segment “over” an intramedullary nail (LON) with subsequent removal of the external distraction device [29, 33–35] also can be considered in this context.

2.8.4 Technical Tips and Tricks for the Humerus and Forearm If the bone fragments have consolidated with shortening of the segment and retention of its axis, limitation of function of the extremity or cosmetic considerations should be considered as indications for reparative surgery.To lengthen the humerus,corticotomy with osteoclasis is performed above or below the zone of the malunited fracture. Assembly of the external fixation device should be similar to that shown in Fig. 2.6.3. When lengthening the arm at the level of the proximal third of the segment, the orientation of the proximal basic support of the Ilizarov apparatus after placement of wires has its particular features. The plane of the proximal basic half-ring should be at an angle of 100–105◦ to the axis of the arm, open to outside. Only after this has been achieved are the wires attached to the support. Then, using elastic deformation of the wires, the proximal basic support is oriented perpendicular to the longitudinal axis of the bone and connected to the transosseous module, which will fix the distal fragment after corticotomy. Thisis necessary for correction of varus deformity of the arm during distraction. Basic supports based on half-pins are placed perpendicular to anatomic axis of the bone. If both forearm bones are shortened uniformly and rotational movements are permanently limited with a significant decrease in the arm force due to the closeness of the muscle attachment points corrective surgery is indicated.If the patient considers the rotational function to be satisfactory, corticotomy with osteoclasis of the ulna is performed usually above the deformation; the equivalent operation on the radius is performed below the union of the bone fragments. If the forearm bones are shortened unequally, as is generally the case, only more shortened bone should be lengthened to restore the relationships in the radioulnar joints. However, it is not improbable that both the ulna and radius need to be lengthened, for example in young patients with an occupation that requires complete restoration of anatomy and function of the forearm. In this case osteotomy in the area of the fragment

210

2 Specific Aspects of External Fixation

a

b

c

Fig. 2.8.12a–c. One-stage removal of angular deformity. Instead of the removal of a wedge-shaped piece of bone (a) hinge osteotomy (b, c) can be performed. When this is planned, using a skiagram, the needle of the calliper is positioned at the point of intersection of the anatomic axes of the proximal and distal bone fragments and a circle is made with a diameter equal to the bone diameter at this level. Hinge osteotomy can be performed either on the distal (b) or the proximal fragment (c)

a

b

c

Fig. 2.8.13a–c. Inappropriate approaches to one-stage removal of angular deformity. If hinge osteotomy is to be carried out based on a circle with a diameter exceeding that of the bone, restoration of the anatomic axis will be accompanied by a decrease in the area of contact of the fragments (a, b). And the further from the apex of the injury the osteotomy is made, the less will be the area of contact of the fragments. Performing hinge osteotomy through the point of intersection of the anatomic axes of the fragments also will lead to lateral displacement of the fragments (c)

a

b 3

1

4

c

2

IV,8,120; VI,3-9 →← VIII,8,90; VIII,3-9 180

3/4 180

Fig. 2.8.14a–c. Examples of external fixation for the one-stage elimination of femur varus deformity (a) after removal of a wedge (b) and after hinge osteotomy (c). It should be noted that the increase in bone length is greater in the latter example

2.8 Basic Principles of Correction of Long-Bone Deformities

a

211

b

Fig. 2.8.15a,b. To form a wedge-shaped regenerate it is necessary that the hinge arms coincide with the projection of the cortical plates on the convex side of deformity (a). The line connecting the hinge units should bisect the angle of the deformity. Placing the hinges on the concave side of the deformity will result in kneading the bone when the arms of the hinges are moved (b). Such a version is acceptable only when removing a minor deformity at the level of the osteotomy or in the presence of osteoporosis (the second axial hinge is “invisible”, because it is located parallel to that shown on the diagram)

a

b

Fig. 2.8.16a,b. The swivel hinge is generally mounted on the concave side of a deformity, parallel to the axial hinge (a). When removing a varus deformity of the proximal third of the femur or humerus, the swivel hinge is set more laterally from the axial hinge, from the convex side of deformity. In this case, each arm of the swivel hinge is connected to an external support by connection plates (b)

212

2 Specific Aspects of External Fixation

a

b

Fig.2.8.17a,b. The greater is the distance from the bone to the swivel hinge, the greater the required magnitude of distraction. A skiagram is used to calculate the required magnitude of distraction (a). The amount of lengthening of the segment after removal of an angular deformity is determined as shown in b

a

b

c

d

e

Fig. 2.8.18a–e. Location of axial hinges at some distance from the bone, but still with the line connecting the hinge units bisecting the angle of the deformity, results in the formation of a trapezoidal regenerate. The further from the bone are the axial hinges (a, c), the greater the segment lengthening obtained (b, d). e Diagram showing how the lengthening of the segment is calculated when forming a trapezoidal regenerate

2.8 Basic Principles of Correction of Long-Bone Deformities

a

213

b

Fig. 2.8.19a,b. If the axis of rotation of the axial hinge is not aligned with the line bisecting the angle of the deformity lateral displacement of bone fragments will result. The more the hinge is displaced relative to the bisector of the angle, the greater will be the peripheral displacement of the fragments. When the axis of rotation of the hinge is located above the bisector, the distal fragment will be displaced relative to the proximal one in the direction of the hinge location (a). When the hinge is located below the bisector, the displacement of the distal fragment will occur in the opposite direction (b)

a

b

c

Fig. 2.8.20a–c. Despite the level of performed osteotomy, axial hinges should be located in the bisector of deformity angle – CORA (a). Only in this case, the mechanical axis will be restored (b). Otherwise, the purpose of operation will not be achieved (c)

214

2 Specific Aspects of External Fixation

Fig. 2.8.21a,b. Diagram of bilocal compression-distraction CEF of a trochanter malunited fracture. By means of corrective osteotomy in the intertrochanteric region, the neck–shaft angle (a) is restored in one stage. Inequality in length of the extremities is removed through formation of the distraction regenerate in the middle third of the segment. In the period of fixation, after lengthening the femur to the required size, the proximal support is dismantled and the reductionallyfixing transosseous element, e.g. VI,9-3, is inserted (b)

a

b 1

2

5

6

4

3

I,8,120; I,11,90 →← III,10,120; IV,8,90 —— VI ←→ VII,8,120; VIII,3-9 (a) 1/3 225 3/4 195 180 3/4 180 7

I,8,120; III,10,120; IV,8,90 —— VI,9-3 —— VII,8,120; VIII,3-9 3/4 195

180

(b)

3/4 180

Fig. 2.8.22a,b. As already noted, the closer to the knee joint the distraction regenerate is formed, the greater is the danger of contracture developing in it. Therefore, when there is epicondyle angular deformity of the femur combined with segment shortening, bilocal compression-distraction external fixation is also advisable (a). When forming a distraction regenerate exceeding 5 cm, the time for its reorganization exceeds the period of fragment consolidation in the epicondyle region. In this case an additional half pin VII,8,70 is inserted and the distal support is dismantled (b)

a

b 1

2

3

6

7

5

4

I,8,120; II,11,90; III,9,70 ←→ V,8,120; IV,3-9 →← VIII,8,120; VIII,3-9 (a) 1/3 225 180 3/4 180 8

I,8,120; II,11,90; III,9,70 —— V,8,120; IV,3-9; VII,8,70 1/3 225

180

(b)

2.8 Basic Principles of Correction of Long-Bone Deformities

a

b

c

d

215

e

Fig. 2.8.23a–e. Versions of fragments displacement in case of their rotation. It is necessary to consider that derotation will not lead to the lateral displacement of fragments only when the longitudinal (anatomic) bone axis does not coincide with the centre of supports (a, b). However, in practice such an orientation of the device supports is used very seldom. If the bone is located eccentrically relative to the centre of the support, simultaneously with derotation lateral displacement of the fragments will occur (c, d). It is eliminated through reciprocal displacement in the plane of the deformity of the transosseous modules fixing the bone fragments (e)

a

b

Fig. 2.8.24a,b. Special methods are used to prevent the peripheral displacement of fragments fixed eccentrically relative to the centre of the support during their reciprocal rotation. For example, at the level of the osteotomy an intermediate ring is placed so that the bone axis coincides with its centre [36]

216

a

2 Specific Aspects of External Fixation

b

c Fig.2.8.25a–c. In this version of rotational deformity correction, a large support is fixed to the proximal and distal transosseous modules. These supports are oriented such that the bone is in the centre of each of them. Between them a derotation unit is placed, e.g. sloping half-pins (a). After osteotomy, the rotation deformity is corrected (b). In the final stage, the transosseous modules are connected to half-pins and the ring supports of larger diameter are removed (c)

2.8 Basic Principles of Correction of Long-Bone Deformities

a

b 2

1

c

3

5

4

I,4-10; I,5,90(I,5,90); (II,9,90) —— III ←→ V —— (VII,10,120); (VIII,7-1) 3/4 120

217

120

120

(a)

120

6

7

I,4-10; I,5,90(I,5,90); (II,9,90) —— III ←→ V —— VII,8,120; (VII,10,120); VIII,6-12(VIII,6-12) (b) 3/4 120 120 120 120 9

8

11

10

I,4-10; I,5,90(I,5,90) —— III,8,90; (IV,10,90) →← V,8,6,90; (V,11,90) —— VIII,6-12(VIII,6-12) 3/4 120

120

120

120

(c)

Fig. 2.8.26a–c. Stages of external fixation in patients with traumatic deformities of both forearm bones

Fig.2.8.27. Elbow deformity of the humerus and forearm bones also can be eliminated both by a single-stage operation and gradually. As an example, the figure illustrates the regimen for external fixation in patients with traumatic varus deformity of the supracondylar area of the humerus, eliminated by a single-stage operation

1

2

4

3

V,10-4; VI,8,70 →← VII,8,115; VIII,3-9 140

3/4 140

218

2 Specific Aspects of External Fixation

union is preferable. After restoring the length of the bones if the ends of fragments are incongruent, their open adaptation may be required. Assembly of the device for the stages of reconstruction may be equivalent to that shown in Fig. 2.8.26.

2.9 Aesthetic Correction of the Lower Extremities3 Aesthetic surgery involves the cooperation of several medical specialties for the implementation of the ideas of a healthy person about physical perfection by means of surgical intervention [37]. Aesthetic surgery of the lower extremities can be considered to be an integral part of both orthopaedics and plastic surgery. The medical indications for correction of deformities are presented in the previous section and involve in principle the restoration of the biomechanical axis and elimination of anisomelia (inequality of length of extremities). Therefore, aesthetic correction (Figs. 2.9.1–2.9.8) should formally include situations where the biomechanical axis is preserved and the extremities have equal length. In this respect it would be reasonable to use the term “curvature” instead of deformity in relation to aesthetic surgery. However, the paradox lies in the fact that modern medicine cannot draw a clear line between the notions of “deformity” and “curvature” as discussed in the present chapter, and indeed deformity of the extremities may be an ethnic feature in some countries. Research conducted by identical methods in Hong Kong, the USA and Sweden has revealed significant differences in deviations of the axis of the extremities from the biomechanical axis of the lower leg between races: among Chinese people the deviation is 5.4±2.5◦ among females and 4.9±2.3◦ among males, and is 3◦ among white Americans and Swedes. The ratio of the occurrence of gonarthrosis to hip arthrosis (for which axis deviation is less significant) was 9:1 among elderly Chinese of Hong Kong,3:1 among white Americans and 2:1 among Swedes. In other words, among the Chinese, in whom curvature of the extremities is an ethnic feature, arthrosis of the knee joints is three times more likely to occur than among white Americans and 4.5 times more likely than among Swedes [38, 39]. These findings lead to the conclusion that everyone having the slightest deviation of the axis should be operated upon on the grounds of the presence of a predisposing cause of arthropathy progression. At the same time according to the data of Vorobiev (1932), Shulyaka et al. (1967) and Straber (1917)

(quoted by Kotelnikov et al. [40]) deviations in the range 6–9◦ from the mechanical axis of the extremity are variants of the norm in the same way as inequalities in the length of the extremities in the range 1.0–3.0 cm [41, 42]. It is therefore justified to use the term “aesthetic deformity of a lower extremity” (AD) when the deviation of the biomechanical axis of an extremity (or extremity segment) from the average value accepted in orthopaedics4 is within the normal range5 . The term “curvature”can also be used as a synonym,but it should not be used in documents not intended for internal use of a medical institution, neither should attention be focused on it in communication with the patient. Varus (173–183◦) and valgus aesthetic deformity (163–171◦) of the lower extremities can be distinguished.An abnormality can be considered a deformity on the basis of clinical signs as well as on the basis of cosmetic or orthopaedic considerations. The deviation of an extremity from the biomechanical axis and/or its shortening accompanied by objective or subjective signs of bone and joint diseases is an object of study and should be considered for operative orthopaedic correction.The objective of aesthetic surgery is the correction of the aesthetic deformity (as a variant of the norm) in patients in whom there are yet no objective or subjective signs of bone or joint disease. The clinical importance of signs that are very close in terms of the external manifestations (varus deformity) in a patient suffering from Blount disease or rachitis and in a patient subjectively displeased with bow-legs will be absolutely different. The criteria for “clinical value” are sure to be specified with time. At the present time those for whom aesthetic corrective surgery can be considered most appropriate from both the aesthetic and orthopaedic points of view are those who seek such surgery and in whom the mechanical axis of the lower extremity can be improved. The orthopaedic contraindications to aesthetic corrective surgery are identical to those to external fixation given in section 1.3. The decisions concerning complicated reconstructive surgery in physically healthy people are a particular responsibility of the physician and require a conscientious attitude on the part of the patient. During the formation of the skeleton the shape and length of legs change, and they are fully developed by 16–17 years of age. Therefore, one should not perform remedial procedures for aesthetic indications at an earlier age. The patient must have no orthopaedic, hormonal or genetic diseases or their consequences. Aesthetic surgery requires a surgeon with special qualifications. 4

3

The material presented was prepared in collaboration with A.A. Artemiev and O.A. Kaplunov

5

172–174◦ [28, 29] 163–183◦ [43–45]

2.9 Aesthetic Correction of the Lower Extremities

One of the major features of aesthetic correction of the appearance is that it is performed according to the wishes of, and to suit, the patient. In this connection the psychological profile of a candidate for an operation and his/her self-appraisal are of special significance [46]. Belousov [47] identifies the following major types of character that affect the self-appraisal: 1. Positive-passive: the person is pleased with his/her appearance but does nothing to preserve it. 2. Positive-active: the person is intensely concerned with his/her appearance and is inclined to approach the surgeon for any reason. 3. Negative-conciliatory: the person is not pleased with his/her appearance but does nothing. 4. Negative-resolute: the person does not strive to improve his/her appearance by means of an operation, but is ready to be operated upon under the pressure of circumstances (family relations, professional standards). 5. Unreasonably critical: minimum deviations from beauty standards are exaggerated. The patient is set only on perfection; therefore,he or she will consider the results of any operation unsatisfactory. Proceeding from the individual characters listed above aesthetic correction is indicated only for individuals of the second and fourth groups. The fifth group comprises people who overstate their requirements which cannot be satisfied. Examples are those who seek to increase their height by more than traction osteogenesis is able to provide or seek to increase their height by an amount that would result in a body shape that is out of proportion, or when the patient sets conditions such as reducing the necessary period of treatment and rehabilitation. However, to obtain a psychological profile it is insufficient to send the patient to a psychiatrist to get a certificate similar to that required for a driving licence or a gun licence. Contact with the patient is an element of preoperative preparation. Long, sometimes hours-long, consultation allows thorough discussion of all the details of the treatment and makes it possible to establish a personal relationship that must be maintained over several months. In this period the patient may experience a moral breakdown, change his or her view on the prospect and success of the enterprise accusing the physician of nonobjective elucidation of the negative sides of the treatment (pain, duration, bulkiness of the device, related restrictions etc.). If this stage reveals such features as hot temper, irritability or weak will that will hinder treatment and contact with the patient, the patient should be refused correction. Identification of such patients and refusal to operate are essential elements of the consultation process and will enable

219

many problems to be avoided. The involvement of a psychotherapist is very helpful in such cases. One of the questions that must be clarified prior to the operation is why the person is determined to make such a step.The most favourable motive is that the correction will improve the ability to perform particular professional tasks. Some kinds of activities (show business, the services, law enforcement and others) set special requirements for height and shape of the legs. Therefore, in these cases the objective of the treatment is confined to the solution of a particular technical problem – correction of the curvature or elongation by a definite number of centimetres. In these cases moral feelings and abstract objectives are less of a consideration. The most unfavourable and doubtful situation for the surgeon is when,by changing his or her appearance, including the shape or length of the legs, the patient expects to solve some personal problems that are hard to formulate even for the patient. Although modern psychology considers such motives as a constructive way of psychological self-assertion [48], the failure to solve these “problems”can negatively affect the evaluation of an objectively excellent result of aesthetic correction.A good psychotherapeutic effect can be achieved by providing the candidate for an operation with the opportunity to communicate with patients who are undergoing or have already completed treatment. To achieve this it is necessary to make check-up appointments for patients at different stages of treatment on the same day. A candidate for an operation must receive exhaustive information about the prognosis, and the severity and duration of the operation and the entire treatment. Special attention should be paid to the probability of complications, the consequences of the operation, anaesthesia and postoperative treatment. There is currently no definite legal basis strictly regulating the relationship between the physician and the patient. If problems or complications occur both parties appear to be legally unprotected. An adequate amount and objectiveness of the information received by the patient prior to the operation represents a pledge of mutual understanding with the physician throughout the long period of treatment and makes it possible to overcome difficulties and complications that can emerge at any stage. No matter in what form the relationship between the patient and the medical institution are formally secured (informed consent, agreement, application etc.), the document should contain the following statements (or statements to the same effect) made by the patient: “I have been warned about the possible complications and I confirm my desire for operative correction of the shape (length) of my legs. I will not make any claim against the medical institution (surgeon) if complications arise provided that there is no negligence in the actions of the medical personnel.”

220

2 Specific Aspects of External Fixation

a

b

c

d

Fig. 2.9.1a–d. The shape of the lower extremities is determined in a neutral stance without tension. a The “ideal” shape of the legs is characterized by the presence of three fusiform gaps along the internal contour limited by the perineum, the touching knees, the soft-tissue mass of the upper third of the lower leg, and the touching ankles. b True bowlegs are manifested as a defect in the internal contour extending from the perineum to the touching ankles. c X-shaped curvature is characterized by the impossibility of closing the ankles. d False curvature is associated with the aesthetically unfavourable distribution of the soft tissue of the lower leg

Aesthetic correction is performed in one stage, on both legs at once.

2.9.1

Shape of the Legs

To determine the type of the aesthetic deformity it is necessary to perform a proper examination. Many of those who have been trying to hide the curvature of their legs for years unintentionally rotate their legs outward and bring their knees close together, which can affect the appraisal of the shape of the legs. For an objective appraisal it is necessary to achieve full relaxation of the muscles of the femur and lower leg. The patient is asked to assume the position of toes-in/heels-out by 1–2 cm (in this position the feet are parallel and the rotation of the extremities is eliminated). This diverts the attention of the patient. It is then necessary to find out what the patient wants. Even with marked curvature a small ﬂexion of the knee joints will make it possible to bring the knees close together and to show the patient the desired result (approximation of the knees). These positions (standing in the neutral-relaxed position and in the position of the desired result) must be photographed. The major types of lower extremity shapes are shown in Fig. 2.9.1. True aesthetic deformity is associated in most cases with deformity of the tibia. False aesthetic deformity is conditioned by specific features of the organization of

the lower extremities that give the impression of curvature without deformity of the bones and are related to the distribution of soft tissue. True aesthetic deformity requires orthopaedic correction. A mandatory condition is the requirement that the correcting osteotomy should not result in deterioration of the biomechanical axis of the extremity or to a deviation of the plane of orientation of the joints from the physiological one. In cases of false aesthetic deformity, if it is impossible to correct the “defect” of the soft tissue by conservative measures, it is recommended that contour plasty be performed using soft implants [49] or to remove a sliver of the tibia (reconstruction of the fibula is discussed below). In cases of false bow-legs, osteotomy to correct the epicondyle by medialization of the distal fragment allows closing of the soft tissue of the lower leg; however, this procedure results in deterioration of the biomechanical axis of the extremity, and valgus of the ankle joint. Nevertheless, in the cases when a true curvature is combined with a false curvature such corrective osteotomy is justified.

2.9.2 True Bow-Legs (Varus) Two types of varus deformity of the lower extremities are the most frequent [12]. In the first type the proximal end of the curvature is located in the prox-

2.9 Aesthetic Correction of the Lower Extremities

a

221

b

Fig. 2.9.2a,b. In the first type of deformity the angle between the proximal and distal supports is equal to the angle ˛ between the axis of the tibia and the mechanical axis of the lower leg. The proximal basic and intermediate rings to allow centreing of the device and the calculated alteration in the axis of the segment are connected by hinges (a). First osteotomy of the distal third of the fibula is performed. After corticotomy with osteoclasis of the tibia and correction of the segment axis the hinges are replaced by half pins (b). The Ilizarov device on each lower leg is as follows: 1

2

3

4

6

5

I,8-2; I,4-10; II,9-3 →← IV,9-3 —— (VII,8-2)VII,8-2; VIII,4-10 3/4 150

150

150

In CEF (a) modular transformation allows first the distal basic support to be removed (b) and then the rear half-ring of the second support to be removed (c) during the fixation period: 1

2

3

6

7

4

5

I,8-2; I,4-10; II,1,90 →← IV,9-3; VI,12,70 —— (VII,8-2)VII,8-2; VIII,4-10 (a) 3/4 150 150 150 I,8-2; I,4-10; II,1,90 →← IV,9-3; VI,12,70

(b)

I,8-2; I,4-10; II,1,90 →← IV,9-3; VI,12,70

(c)

3/4 150

3/4 150

150

1/2 150

imal third of the lower leg; in the second type it is located at the boundary of the middle and distal thirds of the segment (Figs. 2.9.2–2.9.5). The general principles of correction of the angular deformity of the segment are considered in in section 2.8 (Figs. 2.8.10– 2.8.20). The difference between true bow-legs and Xshaped curvatures is that the angular displacement is towards the other side. If the chosen strategy is gradual correction of deformation, the distraction starts on day 4–6 in at 1– 2 mm per day (0.25 mm four to eight times). Usually, 7–10 days are enough for normalization of the biomechanical axis of the extremity under visual and radiographic control. The required amount of distraction can be determined from the displacements in the bone-

device system that emerge during the process of correction. Specific features of the elimination of angular deformities with simultaneous elongation of the segment are described in section 2.8. Mobilization of patients starts the day after the operation so that by the end of the first week they can move freely within the room using crutches and can start using a walking stick within 3–4 weeks. If the surgical trauma is minimal and the fixation is sufficiently rigid, some patients are able to start work or study as early as the end of the first month. The fixation period is usually 2.5–4 months. The decision to remove the device is taken on the basis of the findings of a comparison radiograph and a clinical trial of the union as described in detail in section 2.17. After removal of the device the patient must be advised about gradually increasing the

222

2 Specific Aspects of External Fixation

Fig. 2.9.3. In this variant of correction of a deformity of the first type the device set includes two ring supports based on six 2-mm wires – three wires with stops in each support. The supports are connected by four telescopic half-pins with plane hinges at the level of the osteotomy. In the proximal epimetaphysis the wires are inserted only through the tibia bypassing the fibula head from the front. Such insertion of the wires does not require osteotomy of the fibula as the mobility in the proximal tibiofibular joint allows corrective rotation of the distal fragment of the tibia together with the fibula [12] 1

2

3

6

4

5

I,8-2; I,4-10; II,9-3 —◦— VII,3-9; (VII,8-2)VII,8-2; VIII,4-10 150

150

The hinges are installed so that the external ones coincide with the external contour of the tibia at the level of the osteotomy while the internal ones are more medial on the internal semicircle of the ring support. It is important to ensure the exact alignment of the half-pins between themselves and the lower leg axis and an equal distance between the medial pair of half-pins and the lateral half-pin. Otherwise rotationally angular displacement of the fragments is possible during the process of correction

a

b

c

Fig. 2.9.4a–c. For aesthetically unfavourable distribution of the soft tissue of the lower leg, i.e. combined true and false curvature (a), a good aesthetic result can be achieved by supplementing angular correction (b) with medialization of the distal fragment [37]. Displacement along the periphery of the distal fragment of the tibia of up to 15 mm preserving the mechanical axis within the norm allows the defect of the internal contour of the upper third of the lower legs to be reduced (c). Two methods of medialization are possible: gradual and single-stage [12]. The principal difference between them is the duration of rehabilitation and the possibility of an aesthetically profitable increase in length of the lower leg of 1.5-2 cm with the gradual method. The choice of method primarily decided by the patient after he/she is told about the details of the methods

2.9 Aesthetic Correction of the Lower Extremities

223

Fig. 2.9.5. In the second kind of varus deformity two proximal supports are placed perpendicular to the mechanical axis of the segment. The distal support is placed at an angle equal to the angle of correction. First osteotomy of the distal third of the fibula is performed. Corticotomy with osteoclasis of the tibia is performed at the top of the deformity and the deformity is eliminated. The Ilizarov device is assembled in the following way: 1

2

3

6

5

4

I,8-2; I,4-10 —— V,9-3 —◦— VII,9-3; (VIII,8-2)VIII,8-2; VIII,4-10 3/4 150

150

150

When CEF is used (a) during modular transformation first the proximal basic support is removed (b) and then the posterior half-rings of the remaining supports are removed (c) throughout the fixation period as the bone regenerate is formed: 1

3

2

5

6

4

II,3-9 —— IV,12,120; V,9-3 —◦— VII,9-3; VII,1,120; (VIII,8-2)VIII,8-2 (a) 3/4 150 150 150 IV,12,120; V,9-3 →← VII,9-3; VII,1,120; (VIII,8-2)VIII,8-2

(b)

IV,12,120; V,9-3 →← VII,9-3; VII,1,120; (VIII,8-2)VIII,8-2

(c)

150

150

1/2 150

1/2 150

load on the extremities to achieve full loading within 3–4 weeks.

2.9.3 Legs

Volume and Contour of the Lower

The question as to the most appropriate method for the plastic recontouring (remodelling by taking a sliver of the tibia, reconstruction of the fibula, or soft implant) is resolved on an individual basis. The criteria involved in the decision can be considered to be both objective data (degree and symmetry of hypotrophy, character of the soft-tissue mass of the lower legs, specific features of the segment contours) and the opinion of the patient after he or she is told about the advantages and disadvantages of each kind of plasty. The following circumstances must be taken into account. Bone plasty takes a longer time than plasty us-

ing silicone implants. It is also more traumatic and, consequently, involves a higher operative risk. At the same time a silicone implant is a foreign body and is not always well accepted by the immune system of the host. Infection around the prosthesis can occur and is a greater threat to the patient’s health than soft-tissue inﬂammation in the area of the wire exits. Infection is accompanied by gradual formation of a cicatricial capsule with partial loss of the cosmetic result, but this does not exclude a repeat operation.The effect achieved by bone plasty lasts for life. Plasty of the bones of the lower leg in the presence of hypotrophy of over 30–35% with a comparable volume of the segment at the boundary of the upper and middle third and obliterated subcutaneous and muscle masses is not justified. It will require considerable distraction of slivers of the tibia and fibula, but this will not provide a sufficient aesthetic result due to the slivers showing through in the soft tissue. For cor-

224

2 Specific Aspects of External Fixation

a

b

Fig. 2.9.6a,b. Remodelling the shape of the lower leg for correction of hypotrophy of the external group of lower leg muscles. For gradual displacement of the intermediate fragments of the fibula wires with stops are inserted close to their ends. The ends of the wires exiting on the posteroexternal surface of the shin are fixed by distraction rods to the support bar while the opposite ends are cut off and left under the skin. The splinters of the fibula are moved by tightening the nuts of the distraction rods outwards and backwards. If double osteotomy is performed the middle fragment is abducted taking account of the difference in the thickness of the proximal and distal parts of the lower leg, i.e. the upper end is abducted more than the lower. The average rate of displacement is 0.5–0.75 mm/day

rection of symmetrical hypotrophy of the soft tissue of both lower legs, bone plasty is not appropriate, either, because achievement of symmetry of the tibiae is a complicated process. For this situation, plasty using factory-made soft prostheses has more likelihood of a better outcome. If the patient has expansive hypotrophy of one lower leg of up to 30%, the method should be chosen taking into account the technical possibility of performing a certain method of correction and the patient’s wishes after he or she is informed of all the possible approaches. If atrophy of the soft tissue is present, mostly of the external semicircle of the lower leg, the extremity is remodelled by means of reconstruction of the fibula. We should note that the method of remodelling of the shape of the lower leg was developed following the experiments on lower leg thickening carried out by staff of the Russian Ilizarov Research Center in 1970. The success of development of the basic methods of shin

remodelling followed the research of Ilizarov et al. [50– 52] and Barabash et al. [53]. The method is performed by means of a device based on two basic ring supports installed at the level of the proximal and distal metaphysis of the cannon bone. The supports along the anterior and external surface are connected by rods. From the posterior external surface the supports are connected by means of a support bar.Osteotomy of the fibula is performed via small incisions. An oscillating saw should preferably be used to cut the bone. If atrophy of the external semicircle is seen mostly in the upper half of the lower leg, osteotomy of the fibula is performed at the boundary of the upper and middle thirds. With more extensive atrophy, double osteotomy of the fibula is performed in the upper third and at the boundary of the middle and lower thirds of the segment (Fig. 2.9.6). In severe cases, the external contours can be followed more exactly by osteotomy of the fibula at three levels. In abduction of the fragments the posteroexternal contour of the shin is expanded. In determining when remodelling is complete it should be born in mind that the increase in volume of the lower leg achieved intraoperatively will be partially lost 10–14 days later due to a reduction in oedema. Therefore, with a sufficient initial stock of soft tissue hypercorrection by 1.5–2 cm of the circumference is performed. If atrophy of the soft tissue is present together with the shortening of the lower leg the functional and cosmetic effects are achieved by equalization of the segment length and simultaneous modelling of the shape of the lower leg. If there is a difference in the volumes of the extremities as a result of atrophy of the soft tissues of the internal and external semicircles, additional remodelling of the internal contour is recommended at the expense of slivers of the tibia. In first stage a device comprising two rings is installed on the lower leg. Two slivers the thickness of the cortical layer are formed via three small longitudinal incisions 1.5–2 cm long on the anterointernal aspect of the lower leg (under the tuberosity of the tibia, at the middle of the middle third, and at the boundary of the middle and distal thirds of the tibia) using a narrow chisel from the posterointernal boundary of the tibia. Three transverse channels are made in the bone to the thickness of the cortical layer. Their level is chosen depending on the type and extension of hypotrophy. Then, by turning the chisel along the anatomical axis of the bone, longitudinal osteotomy is performed from the beginning of the upper transverse incision to the middle one and then to the lower one, thus achieving detachment of two slivers. During this operation the tibia can be fractured; therefore, the osteotomy must be performed by a surgeon with experi-

2.9 Aesthetic Correction of the Lower Extremities

225

b

a c Fig. 2.9.7a–d. Scheme for remodelling the internal and external contours of the lower leg. When a wire with a stop is inserted from the side of the bone wound (b) it is not always possible to remove the stop later. An alternative method for transposition of the fragment is to use a console “pushing” wire (c) or the usual wire with a stop (d). In cases c and d a channel somewhat larger than the diameter of the stop is preliminarily made in the anteroexternal cortical plate. In b and d the ends of the wires are fixed by traction clips to the support bar installed along the posterointernal surface of the lower leg. In c the support bar is installed along the anteroexternal surface of the lower leg. Traction starts on the fifth or sixth day at a rate of 0.75 mm/day (0.25 mm three times a day)

ence of working with bone tissue. Wires with stops are inserted through the slivers from the internal surface outwards and backwards: near the ends of the distal fragment and at the proximal end of the distal fragment (Fig. 2.9.7).

2.9.4 Growth and Length of the Lower Extremities Formally, correction of growth in cases of a “low” subjective appraisal category and correction of the length of the lower extremities should be considered separately. However, as both kinds of correction are based on segment elongation by the Ilizarov method, we consider them together. The specific features of external fixation in segment removal from an extremity are considered in section 2.8.As the need for leg shortening for aesthetic reasons arises relatively seldom, we pay primary attention to issues of elongation. Candidates for surgery are conventionally divided into the following groups [37]:

d

1. Those wishing to increase their height: a) by a definite amount to satisfy some professional requirement. b) to overcome various psychological complexes. 2. Those wishing to restore certain body proportions. To achieve the aims and to satisfy the patient’s wishes it is often necessary to resolve completely opposite problems. The maximum possible elongation of the legs may be out of proportion, while elongation by a small amount to achieve certain interrelationships (sometimes clear only to the patient) may be difficult to comprehend. Therefore, successful solution to the problem of aesthetic correction of the length of the lower extremities has two components: 1. An understanding of the primary notions of the norm held by both the physician and the patient. 2. Implementation of the technical (sometimes quite limited) aspects of elongation of the lower extremities. The objective factors inﬂuencing the correlation of individual parts of the body are sex and age.Sexual differ-

226

2 Specific Aspects of External Fixation

No.

Location

1 11 14 15 16 17 21 22 23

Crown of the head Centre of the heads of the humerus Navel Upper anterior iliac bone Pubis Centre of the figure Tip of the middle finger Knee Medial malleolus

Relative distance from the sole of the foot 1.0 0.8 0.61 0.57 0.51 0.5 0.37 0.27 0.04

Fig. 2.9.8. Proportions of the body of an “average person” according to Karuzin and a table made on the basis of the scheme [54]

ences inﬂuence the shape and volume of the extremities rather than the proportions. Therefore, in most cases it is possible to disregard gender-specific features as applied to the problem of leg elongation. As aesthetic operations on children are an exception, age-specific anthropometric features are not relevant either. There are several standards to determine a rational height increase: • Manouvrier index: difference (in millimetres) in height between standing and sitting on the height meter (normal range 760–920 mm). • Lower extremity length from 40% [54] to 47% (quoted in [40]) of height. • Femur length 48% and lower leg length 43% of the total length of the extremity, with a ratio between them of 1:0.91 [54]. • Femur length 32–34% and lower leg length 21–23% of height.

A more detailed and accessible model (with the ability to clinically identify anatomical reference points) is the diagram of Karuzin (cited by Pavlov et al. [55]). This is shown in Fig. 2.9.8 adapted for the particular task – identification of the proportions of the body and segments of the lower extremities. Simplicity and the possibility of clinical identification of the primary clinical reference points without additional instrumental and invasive methods make it possible for anyone to apply it to himself/herself with the help of a physician. However, whichever scheme is applied to identify the ideal proportions, variability in the length of an individual segment of the extremities may often lead to the situation where correction of one of them (the lower leg, for example) restores the “ideal” ratio with the femur length but results in a disproportion between the total length of the lower extremity and body height. However, these standards are relative and vary depending on the body build. Nevertheless, excessive change in these parameters by more than 12–15% negatively affects the overall aesthetic appearance; for example, excessive elongation of the lower legs make the person look like a heron, excessive increase in the length of the lower extremities, even though the segments are in proportion, results in a“short-armed”appearance. Disregard of these considerations leads to unsatisfactory results. Therefore, common sense and limited technical possibilities of the Ilizarov methods allow proper identification of the indications (and contraindications) for elongation of the lower legs to increase the height of healthy people. The most rational approach is simultaneous elongation of both lower legs by the Ilizarov method, as this ensures a symmetrical result and allows situations to be avoided where, after elongation of one extremity by a known amount,a similar correction to the contralateral extremity becomes impossible due to the emergence

2.9 Aesthetic Correction of the Lower Extremities

of complications (most often neurological) during the second stage [56].Femur elongation is technically more complicated and requires a longer stay of the patient in the clinic. Irregular scars are formed in the soft-tissue mass of the upper leg, and there is a higher frequency of specific complications in the form of soft-tissue inﬂammation at the exits of the transosseous elements and stiffness. Another important factor is the amount of elongation (distraction). The effect of distraction rate and amount on the postoperative course and the formation of bone regenerate during elongation of the extremities under experimental and clinical conditions are the subject of a large number of papers by researchers at the Kurgan Scientific Centre [57–59]. The studies of these authors using radioisotopic, densitometric, myographic,and biomechanical/biochemical methods have established the optimal rate (1–2 mm/day) and amount of elongation of the extremities. The optimal elongation is 18–20% of the initial segment length over one stage, which corresponds to 6–7 cm for the lower leg in an individual of height 175 cm. Similar findings have also been obtained by other authors. Vvedensky [60] defines the functionally permissible elongation as the maximum increment in length when the function in the distal joint can be recovered. This value is determined by the response of the neuromuscular apparatus to distraction, and by the reparative and functionally restorative possibilities. It has been established that the functionally permissible single-stage elongation is 20–30% of the initial segment length. The femur length is in the range 405–536 mm in males and 376–483 mm in females, and the lower leg length is 310–445 mm (average 365 mm) in males and 280–390 mm (average 345 mm) in females [61]. Thus, the functionally permissible elongation that is not accompanied by dystrophic changes in the distal part of the extremity is 6–8 cm for the lower leg and 7–10 cm for the femur. The paradox is that elongation in taller people (with a longer lower leg, accordingly) can be more than in shorter people. The studies mentioned deal with elongation of one extremity with different lengths of the lower extremities. Simultaneous elongation of two segments is a much larger load for the organism. Clinical experience has proved that the value of 6–7 cm is the limit up to which full-value distraction regenerates are formed. Elongation can be greater. However, this question must be solved individually taking into account the aesthetic consequences of excessive elongation discussed above. It is impossible to give the patient guarantees of a large amount of elongation prior to the operation.Besides,so far there are no objective clinical, laboratory or instrumental studies that would allow the maximum possible

227

value of elongation to be forecast for every individual patient. Methods of elongation of the extremities have been described in the literature, and the most detailed descriptions are provided in the works of the researchers of the Russian Ilizarov Research Center [59, 62, 63]. Fundamentals of application of external fixation for elongation of the femur and lower leg are given in the previous section. However, it should be taken into account that elongation of a segment that was shortened by trauma and elongation of a “healthy” extremity are different things. The standard rate of elongation (1 mm per day in four stages) must be constantly updated in accordance with the specific features of the formation of the distraction regenerate, the pain experienced by the patient, and condition of the peripheral parts of the extremity. A radiographic examination is performed on the 10th day of distraction, then every 3–4 weeks. If radiographs obtained on the 10th day show a solid regenerate with the possibility of early consolidation of the fragments, the distraction rate is increased to 1.5– 2 mm per day with further regulation according to the radiographic picture. The overall treatment period in elongation of an extremity consists of several periods: 1. From the moment of the operation to the beginning of distraction: 5–7 days. 2. Distraction period: depends on the amount of elongation.The duration of this period in days is usually equal to the amount of elongation in millimetres. 3. Period of remodelling of the distraction regenerate: this is quite individual and depends on the amount of elongation. With elongations of up to 5 cm the treatment period in months conventionally and approximately can be taken to equal the amount of elongation in centimetres. With greater amounts of elongation (6–7 cm) the treatment period increases considerably, sometimes up to 10–12 months. One way to reduce the treatment period is to use automatic highly divided distractors [64, 65] which allow elongation of the tibia at two levels (Figs. 2.8.5 and 2.8.6). However, it should be taken into account that in aesthetic elongation at one of the levels of elongation, usually the distal one, formation of regenerate is often slow and the expected reduction in the treatment period is not realized. If the patient requests it, after elongation of the lower leg it is also possible to elongate the femurs; however, a number of factors restrict the use of this method of height increase. From an aesthetic point of view, as noted above,elongation of the lower extremities by over 12% will create the visual effect of a short-armed ap-

228

2 Specific Aspects of External Fixation

pearance. Many years of experience of height correction shows that after elongation of the shins by the desired amount during the first stage, the major knot of the patient’s psychoemotional contradictions is cut: the patient is free from the inferiority complex, and the patient’s ego is considerably boosted. In a considerable majority of cases, these changes are the reason the patient positively refuses further elongation. Only if the patient is extremely short (150–155 cm) are there grounds to plan the stages and sequence of segment elongations in advance. The most rational approach involves crossed mono- and bilocal elongation of the contralateral femur and lower leg, i.e. the right femur and left lower leg during the first stage and the left femur and right lower leg during the second stage (Figs. 2.8.5 and 2.8.6). This method enables the patient to avoid the inconveniences related to wearing large heels, and reduces the period of the height increase.

2.9.5

Complications

For an objective appraisal of elongation of the lower leg for aesthetic indications it is necessary to consider two different types of outcomes following external fixation: complications and consequences. Complications are conditions that cannot be planned for in advance, require additional operative intervention or reduce the patient’s quality of life [66]. They include: • Injury to the peroneal nerve branches (2.94%). • Wire osteomyelitis (1.96%). • Regenerate fracture (1.96%). Consequences are normal results of the operative intervention, can be forecast and conservatively treated, and do not affect the quality of life or the long-term outcome. In elongation of the lower leg such consequences include transient stiffness of the knee and ankle joints and soft-tissue inﬂammation at wire exit points. A certain degree of stiffness occurs in practically all cases; however, in properly performed osteosynthesis such stiffness is treated well.Soft-tissue inﬂammation is generally responds to conservative management. Objective analysis of complications in aesthetic surgery is extremely important as an excessive complication rate beyond a certain critical level, insurmountable difficulties or unrecoverable errors in achievement of the set objective, that is to improve the quality of life of a healthy person, must lead to careful consideration, and even rejection, of the appropriateness of such methods of treatment. It is only the high professionalism of the surgeon and considerable experience of reconstructive operations combined with the patient’s insistent desire that ensures success in aesthetic surgery of the lower extremities.

2.10 Nonunions, Pseudoarthroses and Long-Bone Defects The external fixation methods given in Table 2.1 are recommended for treatment of pseudoarthroses of the long bones when elimination of the interfragmentary space does not result in shortening of the humerus by more than 8 mm, one of the forearm bones by more than 5 mm, and the femur and bones of the lower leg by more than 10–15 mm. In cases of apparent pathological mobility, the operation should be with closed methods of external fixation under the conditions of skeletal traction on the orthopaedic traction table (Figs. 2.10.1–2.10.9). In cases of closed monolocal compression, external fixation with transosseous device assemblies are used in a manner analogous to the recommended methods for fixation of acute fractures. In the postoperative period longitudinal (axial) compression is performed in cases of transverse direction of the false joint. In cases of oblique bone injury head support and lateral compression is achieved by inserting a wire with a stop near the level of the false joint by means of distraction clips [67]. Head support and lateral compression can be also achieved by mutual repositioning of the supports of the device, for example using external bars (Fig. 1.6.5). Figures 2.10.1 and 2.10.2 show variants of closed monolocal distraction-compression external fixation. The basic supports must be installed perpendicular to the axis of the respective bone fragment. In fixed deformities when wire-based devices are used it is recommended that the modules fixing every bone fragment be positioned in hypercorrection by 5◦ . After that the transosseous modules are connected by hinges located on the convex and concave surfaces. Some of them are for compression and others for distraction, and thus are different from axial and swivel hinges; their use is considered in section 2.8 (Figs. 2.8.15–2.8.19). Methods of closed monolocal consecutive distraction-compression external fixation of nonunions and false joints are applied in cases of longitudinal displacement of the fragments. The specific features of the transosseous external fixation devices are generally analogous to those given in the sections devoted to external fixation of fractures with wrongly positioned bone fragments (Figs. 2.7.2–2.7.4).When the longitudinal repositioning of the fragments exceeds 35–40 mm, the device is mounted only on the basis of basic transosseous elements. Distraction by 0.25 mm three or four times a day starts on the 3rd to the 5th day. If the process becomes painful or if a neurotrophic disorder arises, the distraction rate must be decreased. After elimination of the longitudinal displacement of the fragments, reducing transosseous elements are in-

2.10 Nonunions, Pseudoarthroses and Long-Bone Defects

229

Table 2.1. Methods of external fixation for nonunions and pseudoarthroses of the long bones Method of external fixation Closed monolocal compression

Closed monolocal synchronous distraction-compression Closed monolocal consecutive distraction-compression Open monolocal compression

Fragment displacement Proper axis of the segment or insignificant angular deformity that can be eliminated in a single step Angular displacement of fragments

Longitudinal displacement of fragments (and at an angle) Any kind of displacement

Indications Bone fracture line Degree of pathological mobility Oblique, transverse, Possibility of singleends of the fragstep recovery of the ments congruent segment axis

Oblique, transverse, ends of the fragments congruent Oblique, transverse, ends of the fragments congruent Ends of the fragments noncongruent

Impossibility of single-step recovery of the segment axis Impossibility of single-step recovery of the segment axis Possibility of singlestep recovery of the segment axis

1

Type of osteogenesis Hyperplastic

Hyperplastic

Hyperplastic

Hypoplastic; necessity to remove the ends of the fragments (osteomyelitis, broken implants)

3

4

2

II,5-11 —— IV,9,90 ↔◦↔ VI,8,90 —— VIII,3-9 (a) 1/2 150 140 140 3/4 140 5

a

b

III,11,120; IV,9,90 →← VI,8,90 —— VIII,3-9 140

140

3/4 140

(b)

Fig. 2.10.1a,b. CEF for nonunion of the humerus. During gradual elimination of the angular deformity (at an average rate of 0.25 mm four times a day) forces are created in the device in different directions: distraction on the concave side of the bone and compression on the convex side. At the same time an additional compression force is applied at the junction of the fragments using reductionally fixing transosseous elements

serted to achieve gradual coaptation of the bone fragments (0.25 mm three or four times a day) with subsequent supporting compression of 1 mm every 7– 10 days.

Open monolocal compression external fixation is used when, after open adaptation of the ends of the fragments, bone shortening affecting for the function of the extremity has not occurred. The transosseous

230

2 Specific Aspects of External Fixation

a

b 1

2

3

5

c 6

4

I,8,90; II,11,90 —— IV,10,90 ↔ ° ↔ VI,9,90; VII,8,70 —— VIII,3-9 (a) 1/3 225 3/4 195 180 3/4 180 I,8,90; II,11,90 —— IV,10,90 →← VI,9,90; VII,8,70 —— VIII,3-9

(b)

I,8,90; II,11,90 —— IV,10,90 →← VI,9,90; VII,8,70

(c)

1/3 225

1/3 225

3/4 195

1/3 195

180

3/4 180

1/3 180

devices assemblies are applied in a manner analogous to that recommended for osteosynthesis of acute fractures of the femur and bones of the lower leg. The ends of the fragments are treated in the plane of their maximum contact. Depending on the plane and location of the bone injury, longitudinal or head/lateral compression is applied during the postoperative period. Malunited fractures, false joints and hypotrophic distraction regenerates are treated using a method based on alternate application of “microcompression” and “microdistraction”. Golyakhovsky and Frenkel [68] call it “the accordion method”. It is implemented within 10–15 days using distraction of 0.25 mm twice a day. After 3–5 days of stabilization the fragments are brought together in the same mode. The cycle of compression and distraction must be repeated at least twice. It should be noted that the potential of external fixation to treat all types of false joints goes beyond the listed methods. The methods can be used in combination in some cases. For example, after closed elimination of the longitudinal displacement of the fragments their open adaptation with subsequent compression osteosynthesis is performed because of incongruity of the ends of the fragments.The ends of the fragments can be supplemented (replaced) by some type of bone graft. When the results of preoperative diagnosis and planning indicate that, following open or closed adap-

Fig. 2.10.2a–c. Osteosynthesis of nonunion of the femur using a hybrid device (a). After elimination of the deformity the hinges are replaced with connection rods (b). After a further 1–1.5 months, provided the bone wound healing dynamics are positive with recovery of the function of the extremity, the initial hybrid device can be transformed to the sector device (c)

tation of the fragments, recovery of the axis of the extremity will result in more significant shortening of the segment than is inherent in pseudoarthroses, the diagnosis “defect pseudoarthrosis” or “defect diastasis” is made. To decide upon the method of external fixation these diagnoses are classified into five groups [26]: 1. Defect-pseudoarthrosis with a slit-like intersplinter diastasis and anatomical shortening of the bone. 2. Defect-diastasis with an intersplinter diastasis of more than 10 mm without anatomical shortening of the bone. 3. Defect-diastasis with an intersplinter diastasis of more than 10 mm and anatomical shortening of the bone. 4. Defect-diastasis of the epiphysis without anatomical shortening of the segment. 5. Defect-diastasis of the epiphysis with anatomical shortening of the segment. In defect-pseudoarthroses the first stage involves recovery of the bone axis by means of external fixation and elimination of the longitudinal and lateral displacement of the fragments. Further action depends on the character of the osteogenesis in the zone of the false joint. Hyperplastic type of osteogenesis (stiff false joints) allows monolocal distraction osteosynthesis to be used (Figs. 2.6.2b,c and 2.6.3b,c). Distraction

2.10 Nonunions, Pseudoarthroses and Long-Bone Defects

a

b 1

2

3

c

5

4

I,8,120; II,11,90; III,9,90 ←→ VII,8,70 —— VIII,3-9 (a) 1/3 225 180 3/4 180 7

6

I,8,120; II,11,90; III,9,90 ←→ V,9,120; VI,9-3; VII,8,70 (b) 1/3 225 180 I,8,120; II,11,90; III,9,90 —— V,9,120; VII,8,70 1/3 225

1/2 180

231

(c)

is started on the 5th to the 7th day at a rate of 0.25 mm one to three times a day depending on the results of biochemical tests [69]. In hypotrophic defect-pseudoarthroses,open adaptation of the bone fragments is generally performed. If appropriate bone autoplasty is applied, and simultaneous corticotomy with osteoclasia of the longer fragment is performed. Distraction is started at an average rate of 0.25 mm four times a day on the 5th to the 7th day after surgery. During formation of the distraction regenerate, fixation with compression at the level of the false joint is performed. In hypotrophic defect-pseudoarthroses of one of the forearm bones with the other bone intact, the bilocal consecutive distraction-compression osteosynthesis is used. The longer bone fragment is elongated according to the Ilizarov method. After adaptation of the intermediate fragment with the fragment being joined, supporting axial or head-lateral compression is applied between them.Without interrupting the distraction the relationships in the radioulnar joints are restored. To reduce a chronic dislocation of the head of the radial bone, a reduction-fixation wire is inserted: (I,11-5)I,11-5 or (I,3-9) or (I,9-3). Open reduction of the head of the radius is applied as appropriate. In chronic dislocations of the head of the radius and

Fig. 2.10.3a–c. Variant of external fixation for correction of a hyperplastic false joint accompanied by shortening of the extremity (defect-pseudoarthrosis). Osteotomy is performed perpendicular to the plane of the false joint (a). After formation of a distraction regenerate of the necessary length wire VI,9-3 is inserted to correct the position of the distal fragment (at the same time half-pin VII,8,70 must be disconnected from the support!) (b). During the fixation period, 3–5 weeks before the planned removal of the device, wire VI,9-3 is removed and the internal half-ring is removed from the distal support (c)

marked degenerative dystrophic changes in the proximal radioulnar joint, removal of the radius head may be required instead of open reduction. Wire VIII,612(VIII,6-12) is inserted for fixation of the distal radioulnar joint. When the degree of the defect-diastasis allows closed or open reduction of the bone fragments with no more than minor compression of the soft tissue it is possible to use monolocal compression-distraction osteosynthesis. The recommendations for assembly of transosseous devices in such cases are given in the section on external fixation of open fractures (Figs. 2.6.2 and 2.6.3). A mandatory condition is adequate blood supply to the ends of the fragments. This type of osteosynthesis is recommended when both bones of the forearm show an equal degree of diastasis. In the presence of avascularity of the ends of the fragments, defects of less than 5–6 cm (10–15% of the segment length) can be replaced by elongation of one of the fragments – bilocal compression-distraction osteosynthesis (Fig. 2.6.7). If one of the bones of the forearm is intact, the approach to external fixation with a defect-diastasis of the second bone is analogous to that for replacement of traumatic defects of the forearm bones (Fig. 2.6.8). If shortening of the bone is still apparent after reduction

232

2 Specific Aspects of External Fixation

Fig. 2.10.4a,b. Diagram of external fixation for correction of a defect-diastasis of the ulna. The transosseous element VI,7,90 is a 4-mm half-pin. The console wire V,5,90 (a) is additionally inserted for rotational stability of the intermediate fragment. After joining of the intermediate fragment to the distal fragment the transosseous elements of the intermediate support are replaced because they cut into the soft tissues (b). Replacement of wire VIII,6-12(VIII,612) with half-pin VIII,6,120 allows correction of rotational movements to start

a

b 1

2

3

6

7

5

4

I,4-10; I,5,90(I,5,90); II,6,90 ←→ V,5,90; VI,7,90 →← VII,7,110; VIII,4-10 3/4 130

130

8

(a)

130

9

10

I,4-10; I,5,90(I,5,90); II,6,90 ←→ V,8,120; VI,4-10 →← VII,7,110; VIII,6-12(VIII,6-12) (b) 3/4 130 130 130

of the fragments, the distraction must be continued until the anatomy of the radioulnar joints is restored. Figure 2.10.4 shows, as an example, the stages of external fixation in defect-diastases of the ulna. Large defects of the femur and tibia are replaced by elongation of both bone fragments – polylocal compression-distraction osteosynthesis (Fig. 2.10.5). The average distraction rate for elongation of the proximal fragment is 0.25 mm three or four times a day. To avoid formation of a hypoplastic distraction regenerate the distal fragment is elongated by 0.25 mm two or three times a day. Therefore, the defect is replaced mostly as a result of elongation of the proximal fragment.The bone defect can also be replaced using polylocal elongation of the fragment. Figure 2.10.6 shows, as an example, the sequence of osteosynthesis in segmental defects of the femur. During the replacement of all segmental defects of the long bones, after approximation of the displaced fragment to the primary position it is necessary to determine whether open reduction is appropriate. Removal of the closing plates and anatomic alignment of the ends of the fragments optimizes the conditions for successful healing of the bone wound. If the ends of

the fragments are hypotrophic or hypovascular plasty can be performed according to the method of AlbiKhakhutov or a spongy autograft can be placed in the groove between the fragments. Open reduction of the fragments is performed in a single stage with partial remounting of the device which involves relocation of the external supports and insertion of transosseous elements. If the blood supply to the ends of the fragments is adequate, the diameters of the fragments are identical and anatomically closed alignment is possible an open intervention may not be necessary. An alternative to polylocal replacement of large tibial defects is reconstructive tibialization of the fibula [70]. One of the most widely used variants is gradual relocation of the fragment of the fibula to the area of the tibial defect: “fibula transport” (Fig. 2.10.7). Operations when the fibula forms a synostosis with the tibial fragments outside the defect, and combining synostosis formation with elongation of a fragment of the fibula can be categorized as complicated reconstructive-recovery interventions. They should be performed only by a specialist experienced in the use of external fixation. Figure 2.10.8 shows an example of one such intervention.

2.10 Nonunions, Pseudoarthroses and Long-Bone Defects

a

b 1

2

3

5

233

c 8

9

4

6

10

5

(I,8-2)I,8-2; I,4-10; II,1,90 ←→ III,3-9; III,4-10 ←→ VI,2-8; VI,4-10 ←→ VII,1,90; (VIII,8-2)VIII,8-2; VIII,4-10 (a) 3/4 150 150 150 150 (I,8-2)I,8-2; I,4-10; II,1,90 —— IV —— VI —— VII,1,90; (VIII,8-2)VIII,8-2; VIII,4-10 3/4 150

150

150

(b)

150

(I,8-2)I,8-2; I,4-10; II,1,90 ←→ IV,3-9; V,12,90 →← V,3-9; V,12,90 ←→ VII,1,90; (VIII,8-2)VIII,8-2; VIII,4-10 3/4 150

150

150

150

(c)

Fig. 2.10.5a–c. Polylocal osteosynthesis for replacement of a segmental defect of the tibia. Note the necessity for stepwise replacement of the transosseous elements transferring the fragments towards one another for distraction-guiding wires (b) and then for transosseous elements (c). The last stage comprises resetting of the intermediate rings at the level of insertion of the transosseous elements. This aspect is expanded on in more detail in the section devoted to external fixation of open fractures (Fig. 2.6.6)

One of the difficulties in relocating a fragment during bilocal osteosynthesis is retraction of the soft tissue in the area of the defect. To prevent perforation and necrosis of an indrawn scar it is necessary to change the direction of the bone fragment movement temporarily towards uninjured soft tissue (Fig. 2.10.9). On the lower leg it is generally necessary to change the vertical direction of movement of the intermediate fragment (coaxially to primary fragments) in order to achieve outward and backward relocation (Fig. 2.10.9a). After the repositioned fragment has passed the scar zone, the distraction guiding wires are replaced by a wire (or wires) with a stop inserted in the ring. Thus the displaced fragment is moved towards the distal island fragment, thus forcing the scars inwards and forwards (Fig. 2.10.9b).

If it is impossible to prevent completely soft-tissue retraction between the fragments, the following approach should be adopted. The displaced fragment is approximated as far as possible to the primary fragment and then their open reduction is performed. The defect arising as a result of the excision of the soft tissue is covered with locally mobilized skin or by a free skin graft. The method involving compression of the soft tissue between the fragments is acceptable but carries the risk of infectious complications. Large defects of the soft tissue must have recovered before replacement of the bone defect. The best results are achieved using vascularized full-thickness autotransplants. In some cases defects of the bone and soft tissue can be treated in a single step by microsurgery.The best

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2 Specific Aspects of External Fixation

a

b 1

2

3

c

7

8

6

4

5

I,8,90; II,9,90; II,11,90 ←→ III,9,90 ←→ VI,9,90 →← VII,8,120 VIII,3-9; VIII,4,90

(a)

I,8,90; II,9,90; II,11,90 ←→ IV ←→ VI →← VII,8,120; VIII,3-9; VIII,4,90

(b)

1/3 225

1/3 225

3/4 195

3/4 195 9

195

3/4 180

195

10

3/4 180

12

11

I,8,90; II,9,90; II,11,90 ←→ IV,8,90; IV,20,90 ←→ VI,9,90; VI,9-3 →← VII,8,120; VIII,3-9; VIII,4,90 (c) 1/3 225 3/4 195 195 3/4 180

Fig. 2.10.6a–c. Bilocal elongation of the proximal fragment of the femur. First the supports of the device are mounted. Insertion of half-pins in the fragments being transposed is necessary to perform corticotomy as well as to optimize the conditions during the early stage of distraction regenerate formation. The distraction-guiding wires can be inserted immediately during the first stage of the operation. After mounting the device, corticotomy with osteoclasia are performed at the distal level and then at the proximal level (a). The rate of movement of the distal fragment must be greater than that of the proximal fragment. If there are signs that the half-pins are cutting into the soft tissue, which is associated with the risk of inflammation, they are removed. Further movement of the fragments is performed by distraction-guiding wires. Approximation of the distal fragment is continued so that it makes contact with the fragment being transposed as early as possible (b). After the distal fragment being transposed makes contact with the primary fragment the distraction is continued until the planned amount of segment elongation is achieved. After that the device is partly remounted: the distraction-guiding wires are removed, the supports are placed at the level of the fragments being transposed and the latter are stabilized by transosseous elements (c)

approach to treating segmental defects of the humerus and forearm bones may be by using autotransplants from the fibula, the wing of the ilium or a rib. The transplant is fixed either by an external fixation device or by combined tension osteosynthesis (Figs. 2.11.12, 2.11.18, 2.11.19, 2.11.21–2.11.23). The lack of external supports, connection rods and transosseous elements in the area of the autotransplant facilitates the microsurgical stage of the operation as well as postop-

erative monitoring of the neurovascular status of the ﬂap. Quite frequently in clinical practice a patient presents with a false joint or a defect or shortening of the femur or tibia together with stiffness of the joints. Recommendations for the treatment of this group of patients are given in the sections devoted to application of external fixation in cases of pathology of the large joints.

2.10 Nonunions, Pseudoarthroses and Long-Bone Defects

235

Fig. 2.10.7a,b. Replacement of a tibial defect with a fragment from the fibula: “fibula transport”. For transposition of the fibula wires of diameter of 1.5 mm are used. To avoid damage to blood vessels and nerves the transposition rate should not exceed 0.25 mm four to eight times a day (a). After the fragment of the fibula has reached the necessary position, open adaptation of its ends with the ends of the tibia is performed and additional stabilizing wires are inserted: in b these are wires (III,3-9) and (VI,3-9). If there are signs of inflammation around the wires used for transposition of the fragment and/or pain caused by cutting into a large amount of soft tissue thus causing restriction of movement, these wires are replaced by wires (III,4-10) and (VI,4-10) or half-pins (IV,1,70) and (V,1,120)

a

b 1

2

3

7

8

150

150

4

6

5

(I,8-2)I,8-2; I,4-10; II,1,70 ←→ (III,7-1) —— (VI,7-1) ←→ VII,1,120; (VIII,8-2)VIII,8-2; VIII,4-10 3/4 150

150

9

10

(I,8-2)I,8-2; I,4-10; II,1,70 →← (III,7-1); (III,3-9) —— (VI,7-1); (VI,3-9) →← VII,1,120; (VIII,8-2)VIII,8-2; VIII,4-10 3/4 150

150

Fig. 2.10.8. Reconstructive tibialization of the fibula [70]

(a)

150

150

(b)

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2 Specific Aspects of External Fixation

a

b

Fig. 2.10.9a,b. Transposition of an intermediate fragment to correct a defect of the soft tissues. For a defect of the soft tissues of the lower leg it is necessary to change the vertical (coaxially to primary fragments) direction of transposition of the intermediate fragment to an outward and backward transposition (a). After the fragment being transposed has passed the scar zone, the distraction-guiding wires are replaced by a wire (or wires) with a stop inserted in the plane of the ring to enable the fragment being transposed move towards the distal island fragment thus forcing the scars inwards and forwards (b)

2.11 Combined Strained Fixation of the Long Bones Combined strained fixation (CSF) is a variant of combined external fixation (CEF) (Figs. 2.11.1–2.11.33). In CSF the long bones fragments are fixed intraosseously by inserted thin fasteners (wire or wires), one end of which is fixed to one of the fragments externally and extraarticularly, while the other with a controlled force is tensioned in the transosseous module mounted on another bone fragment. Each compression wire during insertion and exit from the medullary cavity perforates one compact layer on the one side of the hand and in places where the soft tissue volume is less and there are no major neurovascular formations (Fig. 2.11.1). The method is a combination of intramedullary compression and transosseous fixation. The term “strained” is used to stress the dynamic nature of the compression forces applied at the junction of the fragments. The effect is achieved both by special devices for tensioning the axial compression wires (calibrated springs, for example) and by elastic deformation of the basic transosseous elements. The general provisions of the CSF method are:

Fig. 2.11.1. Scheme for CSF of the femur. The intramedullary wires are “axial compression wires” which emphasizes the biomechanical principle of this type of fixation. The transosseous elements of the module for axial compression wire tensioning are “basic” transosseous elements

1. Identification of indications and the basic equipment for the procedure. 2. Preoperative preparation including choice of angle and level of axial compression wires in the medullary cavity.

3. Axial compression wire insertion in the medullary canal. 4. Axial compression wire insertion through both fragments.

2.11 Combined Strained Fixation of the Long Bones

237

5. Release of the axial compression wires from the medullary cavity and their external fixation. 6. Mounting of the transosseous module. 7. Gradual tensioning of the axial compression wires in the transosseous module. 8. Implementation of the postoperative protocol. CSF is used to create a stop between the bone fragments in the following circumstances: 1. In cases of diaphyseal and metadiaphyseal fractures, slowly joining fractures, false joints. 2. For correcting osteotomies. 3. For replacement of segmental bone defects with osteoplasty material. Details of indications are given in the sections dealing with CSF of the humerus, femur, and the bones of the forearm and lower leg. Contraindications to CSF are identical to those for CEF (page 6). The specific contraindications are: 1. Growth zones located where axial compression wires transit 2. Narrow medullary canal less than 4 mm. 3. Marked osteoporosis with the possibility of perforation of the medullary cavity wall with an axial compression wire in an unplanned place.

2.11.1 Equipment for CSF and Principles of Application As well as the standard equipment for external fixation described in section 1.4, CSF requires the following special devices: 1. A device to determine the angle and level of insertion of axial compression wires in the long bone (Fig. 2.11.3). 2. A conductor for insertion of axial compression wires in the medullary cavity (Fig. 2.11.5). 3. Wire reamers (Fig. 2.11.6). 4. Axial compression wires with stops (Fig. 2.11.7). 5. A conductor for wire stops (Fig. 2.11.11). 6. External supports (Figs. 2.11.19 and 2.11.29). These devices are described below, together with a discussion of their purpose and principles of use. A principal part of CSF is insertion of axial compression wires.When inserted at an acute angle into the medullary cavity, the wire reaches the opposite cortical plate, slides down it for some distance and then returns to the insertion side declining during the passage.Thus, the axial compression wire results in a characteristic three-point single-plane deformity that we refer to as a “transient” or “mounting” deformity (Fig. 2.11.2). The specific features of the axial compression wire deformity in the medullary cavity create the need to individualize the parameters of wire insertion for every

Fig. 2.11.2. Dependence of the distance of the intraosseous transit of the axial compression wire on the wire insertion angle and diameter of the medullary cavity. It has been experimentally established that the distance from the insertion point to the exit point of the axial compression wire depends on the properties of the wire (diameter, flexibility), the angle and level of insertion, and the diameter and shape of the medullary cavity. In particular, the less the internal diameter of the bone and the larger the wire insertion angle, the less the distance from insertion point to the exit point. The specific features of axial compression wire insertion into the medullary cavity of the forearm are given in Fig. 2.11.17

particular situation. This is achieved by means of a special device (Figs. 2.11.3 and 2.11.4). To insert an axial compression wire in the medullary cavity quickly and with minimal trauma (Fig. 2.11.7) the conductor (Figs. 2.11.5, 2.11.8 and 2.11.9) and special reamer (Fig. 2.11.6) are applied carefully at the calculated angle. Before insertion into the conductor, the end of the axial compression wire that is to be inserted is bent at an angle of 170–175◦ for a distance of 2–3 mm and an opposite bend in the same plane is made at the other end. The wire is inserted until it rests against the opposite cortical plane. The wire is then grasped with ﬂat-nosed pliers 3–5 cm from the conductor and the wire is progressively inserted by hammer taps to the pliers (Fig. 2.11.10). If the wire is being inserted correctly there is insignificant resistance to its passage. As the wire is further inserted the pliers are moved keeping the wire at an angle of 5–10◦ more than the angle of the canal in the cortical plate. When the wire enters the metaphyseal part of the bone some resistance to its passage can be felt. To avoid deformation of the wire, strict control of the insertion force is necessary. The force required to insert the wire increases as the angle of insertion increases and the diameter of the medullary cavity decreases. In addition to the above discussion, there are also specific recommendations for the insertion of axial compression wires: • It is necessary to acquire the skill of graduating the force for insertion of the wire into the medullary cavity on osteosynthesis the models.

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2 Specific Aspects of External Fixation

Fig. 2.11.3. Device to determine the angle and level of insertion of a flexible wire into a long bone. The device enables experimental determination of the parameters for axial compression wire insertion in the individual patient. It consists of a rectangular elastic plate 1 with five holes on each long side with inserted threaded rods 2 provided with domed nuts 3 on both sides of the plate 1. The ends of the threaded rods are inserted into the holes of the adjacent elastic plates 4, one on each side. Plates 4 are fixed on the threaded rods in a similar manner to plate 1 by means of domed nuts 3. The ends of the threaded rods are secured by rigid strips 5 forming the top and bottom of the device. A sliding bar with slots on its outer ends 6 can be moved along plate 4 in both directions. On one side of the sliding bar 6, a guide tube 7 is fixed via a hinge, with a calibrated screw 6 mounted so as to allow adjustment of the angle of tilt of the tube

Fig. 2.11.4. Determination of the parameters for axial compression wire insertion. To allow for any apparent increase in the diameter of the medullary cavity on the radiograph, a scale marker (for example, a metal ball of diameter 10 mm) should be visible on the radiograph. The required radiography plane depends on the plane of insertion of the axial compression wire. A skiagram is made reconstructing the actual dimensions of the medullary cavity. To identify the angle and level of insertion of the wire into the medullary cavity, the device is placed with its lateral side on the skiagram. By bending the elastic plates, the curvature of the cortical layers of the bone is simulated and the plates are stabilized using the nuts. Then by changing the angle and moving the sliding bar, the necessary trajectory of the wire in the simulated medullary cavity is empirically determined, i.e. the trajectory that would ensure the planned level of insertion of the axial compression wire going beyond its limits during surgery

2.11 Combined Strained Fixation of the Long Bones

239

Fig. 2.11.5. The guide for insertion of the axial compression wire into the medullary cavity consists of two rigidly connected tubes 1 of diameter of 1.7 mm and 3.5 mm. The inserted end of the guide is cut off at an angle of 25◦ . A tubular fixator 2 with an inserted calibrated wire 3 is rigidly connected to the opposite end of the guide at an angle of 60◦ . Marks on the wire show the angle of the tubes. A strip 5 is connected to the noninserted end of the tubes and in the same plane at an angle of 30◦ by means of a threaded connection. A second tubular fixator 6 with an inserted calibrated wire 7 is rigidly connected to the free end of strip 5 at an angle of 90◦

Fig. 2.11.6. Wire reamers of diameter of 3 mm and length 20 cm are intended for formation of a channel in the cortical plate for insertion of the axial compression wire. Their specific feature is the threaded end with two nuts screwed onto it. They are screwed to a specified distance from the outer end of the conductor, thus making a stop for further insertion of the reamer

a

b

Fig. 2.11.7a,b. For CSF of the clavicle, humerus and ulna axial compression wires of diameter 2 mm and length 40 cm are used. For osteosynthesis of the femur and tibia axial compression wires of diameter 2.5 mm and length 5.5 cm are used. The inserted end of the wires is provided with a metric thread 5 mm long with threaded stops screwed onto it. To avoid overtwisting the wires when they are screwed out, the stops for fixation of the wires on the humerus and femur are provided with slots. For the same reason their threaded channel is positioned eccentrically (a). For osteosynthesis of the clavicle, ulna and tibia the stops for the axial compression wires must have a shearing angle of 25–30◦ (b). The use of threaded stops facilitates removal of the wires if inflammation occurs at their exit point – the wire is screwed out of the stopper

240

2 Specific Aspects of External Fixation

Fig. 2.11.8. Insertion of an axial compression wire into the medullary cavity. Using convenient bone landmarks (greater trochanter, epicondyles, etc.) to locate the bone level identified experimentally, a guide with a wire preliminarily inserted in its 1.7-mm tube is brought close through a skin puncture. It is necessary to make sure that the inserted end of the conductor is placed right in the middle of the plane of the centre of the medullary cavity diameter. The conductor is inserted at an angle of 40–45◦ to the long axis of the bone and a wire is inserted through the adjacent cortical plate by means of a drill, thus fixing the conductor. In the tubular fixator the controlling (calibrated) wire is fixed at the level of the mark designating installation of the conductor at the necessary angle. The reamer is inserted into the bone into the second guiding tube of the conductor as far as it will go and the nuts at the end are screwed to a distance from the edge of the conductor equal to the thickness of the cortical plate. Together with rotation of the reamer the device is smoothly lowered until the controlling wire meets against the bone. After that the adjacent cortical plate is perforated. The reamer nuts resting against the edge of the conductor restrict the drilling depth, preventing drilling of the opposite cortical tissue

Fig. 2.11.9. Insertion of an axial compression wire into the medullary cavity of the forearm bones. If the wire is inserted near a joint, in the direction opposite to it a screw post is used. The difference in the conductor use is in the fact that the controlling calibrated wire is immediately installed with a rest against the bone. The angle of the conductor installation is reduced until the control mark appears at the tubular fixator of the post. The reamer is removed

2.11 Combined Strained Fixation of the Long Bones

241

Fig. 2.11.10. The axial compression wire is inserted into the medullary cavity using a “punching” technique. A drill should not be used as it will cause mixing of the medullary cavity and breakdown of the wire Fig. 2.11.11. The conductor for the wires with stops can be a standard nanoscope with halfthinned and cone-shaped working forceps

• • • •

The angle of wire insertion should be ﬂatter, the wider the medullary cavity and the more marked the osteoporosis. In the presence of osteosclerosis, to perforate the cortical plate, a wire of larger diameter should be used. In the presence of false joints, the canal of the medullary cavity should be restored before attempting to insert a wire. If one has not fully mastered the technique of CSF, radiographic monitoring (ﬂuoroscopy) should be used at all stages of wire insertion.

With proper insertion, the axial compression wire perforates the cortical plate in the metaphyseal area and becomes accessible to palpation. A 10-mm incision is made in this area and the wire is brought out by punching. A conductor for wires with a stops is inserted in the incision as far as the bone (Fig. 2.11.11), the stop is screwed onto the wire and by pulling at the free end the stop is inserted as far as the bone. The incision is closed with one or two stitches. Assembly of the transosseous module for tensioning of the compression wires is specific for every segment, but is subject to the general rule: deformational forces are most effectively resisted by tensioning compression wires of minimum size. Special devices are used to monitor and regulate the tension in the wires, for example distraction clips and calibrated springs. After wire tensioning the condition of the soft tissues is examined: the skin tension must be eliminated by means of small incisions at the exit points of the transosseous elements and axial compression wires. In the postoperative period, the tension of axial compression wires is maintained by tightening the nuts on the distraction clip by an average 1 mm every 10 days if measuring devices are not available.

2.11.2

Humerus

CSF is used when it is possible to ensure an end stop at the junction of the bone fragments. Thus, the indications for the use of CSF in cases of injury to the humerus and forearm are: 1. Transverse and short oblique fractures of the proximal humerus and the upper third of its diaphysis (injuries 11-A2, 11-A3, 12-A3.1, according to the AO/ASIF classification). 2. Slow-setting fractures and nonunions at the mentioned locations with a transverse line of injury or a line close to it with preservation of coaxiality of the bone fragments or the possibility of its restoration in a single step. 3. Traumatic dislocations provided they can be reduced in a single step before fixation. 4. Segmental defects (including joint defects) of the humerus (for transplant fixation). Axial compression wires should not be inserted through growth zones. For fixation of the humerus, the compression wires are inserted from the external aspect of the shoulder. This is done using a frontal radiograph. After determination of the contour of the internal cortical plate and the size and shape of the medullary cavity, the shape is modelled with the plates of the device shown in Figs.2.11.3 and 2.11.4. The optimal angle of insertion of the wire in humerus fixation is in the range 140◦ to 150◦ to the anatomical axis of the distal fragment (the angle is proximally open). By moving the bar of the device which changes the angle of the guide tube, the course of the wire where it exits the medullary cavity at the top of the trochanter is determined. The result of this

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2 Specific Aspects of External Fixation

evaluation provides information on the optimal configuration of the axial compression wire, which can be expressed, for example, as follows: “For the axial compression wire to penetrate the cortical plate in the area of the major tubercle on leaving the medullary cavity it must be inserted into the medullary cavity from the external aspect of the shoulder at an angle of 150◦ at a distance of 19.5 cm from the trochanter or at an angle of 145◦ at a distance of 17 cm from the trochanter.” The narrower the medullary cavity, the larger the wire insertion angle. It is important to note that during formation of the canal at the determined level, the reamer must perforate the skin a slightly more distally to take account of the thickness of the soft tissue (Figs. 2.11.5 and 2.11.8). The reamer is temporarily inserted in the head of the humerus and is used as a lever. Then closed or open reduction of the bone fragments is performed from the minimum approach and they are fixed by two wires. The quality of the reduction and orientation of the axial compression wires in the medullary cavity are determined from comparison radiographs. To avoid insertion of the wire through the acromial process of the scapula, the shoulder is maximally adducted. The axial compression wire is then inserted by punching through the central fragment, its exit oriented by means of controlled counter-ﬂexure of the external aspect of the segment. If the comparison radiograph shows that the wire is apparently coming out more medially than this area (inserted through the acromial process), the bending of the guiding end of the wire is increased by 5◦ , the guiding end of the wire is pulled back by pulling (not rotating!) at the opposite end of the wire as far as the fracture level, and the wire is again brought out by punching. If the wire is brought out more laterally than the designated zone (has passed the fracture line), the bending of the guide end of the wire is decreased. The stop is screwed onto the central end of the axial compression wire (Fig. 2.11.7). The skin is dissected away with a scalpel according to the size of the stop and a canal is formed in the soft tissue with a clip. The stop is then plunged as far as the bone by pulling at the opposite end of the wire. To reduce trauma to the soft issues, a guide for wires with stops is used (Fig. 2.11.11). The skin is closed with a suture. A transosseous module is then mounted for tensioning of the axial compression wire. The 5-mm halfpin VI,8,120 is inserted into the humerus and a connection plate bent in the plane is fixed to the external end of the half-pin. The axial compression wire is tensioned in the connection plate with the help of a distraction clip (with a force of 245–294 N (at 12-A3.1 with a force of 294–343 N) compressing the junction of the fragments (Fig.2.11.12a).The wire module VII,9-3;VIII,3-9;

a

b

Fig. 2.11.12a,b. Schemes for CSF of fractures, non-unions and defects of the humerus. Variant a is preferable: (1) if no marked osteoporosis is present; (2) when the soft tissues thickness at which the console length (the distance from the level of the half-pin closing in the bone to the tensioning node of the axial compression wire) does not exceed 60– 70 mm; and (3) if the diameter of the bone at the level of insertion of the half-pin is at least 30 mm

VIII,10-4 can be used as the transosseous subsystem for tensioning the axial compression wire (Fig. 2.11.12b). The technique of CSF for false joints of the humerus is the same as that for acute trauma. In case of indications to decortication or osteoplasty it facilitates control over insertion of the axial compression wire. The axial compression wire is tensioned with a force of 294–343 N. With traumatic deformation of the proximal part of the humerus, insertion of the axial compression wire must be preceded by removal of a wedge of bone or a hinge osteotomy. The axial compression wire is inserted under visual control after restoration of the bone axis. To restore segmental defects of the humerus (mostly in the proximal part) of up to 40 mm, free autotransplants from the wing of the ilium are used. For long defects vascularized autotransplants from the fibula can be used. At the ends of the bone fragments the internal cortical layer is removed to a depth of 3–5 mm first with a reamer and then with a cutter. The ends of the transplant are pressed into the resulting slots. To prevent “telescoping” of the transplant with the humerus diameter exceeding that of the transplant, blocking wedges of bone graft are used.

2.11 Combined Strained Fixation of the Long Bones

After stabilization of the transplant by CSF, a vessel suture is inserted using microsurgical equipment. The operation is completed by the installation of the additional module II,5-11; II,8,90 or I,10,90; II,8,90 which is connected to the module of the axial compression wire tension. 2,5. The proximal module is dismantled 3 months later providing that there are radiographic signs of bonding between the transplant and the fragments (Fig. 2.11.12b).

2.11.3

Femur

CSF is used when it is possible to ensure an end stop at the junction of the bone fragments. Thus, indications for CSF of injuries to the femur are: 1. Transverse and short oblique intertrochanteric and subtrochanteric fractures (31-A3.2,32-A3.1 according to the AO/ASIF classification), supracondylar fractures (33-A1.3). 2. Slowly setting fractures and nonunions of the mentioned locations with a transverse line of injury or a line close to it with preservation of the coaxiality of the bone fragments or the possibility of its restoration in a single step. 3. Intra- or subtrochanteric,supracondylar correcting osteotomy after which the end stop between the fragments can be placed (transverse, hinge, elbow according to Repke, Kryuk, McMarrey type, etc.). Axial compression wires should not be inserted through growth zones. For CSF of the proximal part of the femur, the axial compression wire is inserted from the external aspect of the distal fragment. For fixation of fractures in patients under 50 kg in weight, one axial compression wire is used; in other patients the insertion parameters are determined for each of the wires. To determine the angle and level of wire insertion, a frontal radiograph is used. If after osteotomy the spatial orientation of the proximal fragment can be changed in a single-step, this is shown on the radiograph. The optimal angle of wire insertion for humerus fixation is in the range 135–145◦ (the angle is proximally open). By moving the bar of the device which changes the angle of the guide tube, the course of the wire where it exits the medullary cavity at the top of the trochanter major (Fig. 2.11.4). The result of this evaluation provides information on the optimal configuration of the axial compression wire, which can be expressed, for example, as follows: “For the axial compression wire to penetrate the cortical plate in the area of the trochanter major on leaving the medullary cavity it must be inserted into the medullary cavity from the external aspect of the femur at an angle of 135◦ at a distance of 17 cm from the trochanter. The second axial compression wire should be inserted at an

243

angle of 145◦ at a distance of 21 cm from the trochanter.” The narrower the medullary cavity, the larger the angle of insertion of the axial compression wire. The operation is performed on the orthopaedic traction table with a pelvis bench with the patient supine. Fixation starts with marking off the proximal axial compression wire. The reference point is marked on the skin and a step is made distally to take account of the soft tissues thickness. The guide for insertion of the axial compression wire is taken through the skin puncture to the bone, fixed and installed at the specified angle with the help of a control (calibrated) wire (Fig. 2.11.8). A canal is formed using a wire reamer in the adjacent cortical plate. An angle of 175◦ is formed in the guiding threaded end of the axial compression wire; a control counter-angle is formed in the opposite end for proper orientation of the wire on insertion. The wire reamer is extracted and the axial compression wire is inserted into the medullary cavity; the guide is removed. An awl is temporarily inserted into the mass of the greater trochanter and is used as the counterstop. The axial compression wire is gripped with ﬂatnosed pliers 40–50 mm from the skin and inserted by hammer taps to the pliers through the medullary cavity to the level of the fracture. As the wire is inserted the pliers are moved distally. In the case of fractures, a reamer is inserted into the greater trochanter and is used as a lever. Then closed or open reduction of the bone fragments is performed from the minimum approach and they are diafixed with two wires. The quality of the reduction and orientation of the axial compression wire in the medullary cavity are determined on comparison radiographs. The femur is adducted to the maximum. The axial compression wire is inserted by punching through the central fragment, its outlet oriented to the external aspect of the segment. The wire must penetrate the femur from the inside at the top of the greater trochanter. If the wire has deviated towards the neck of the femur, the angle of bending of the guide end of the wire is increased by 5◦ , the guide end of the wire is pulled in by pulling (not rotating!) the opposite end of the wire as far as the fracture level, and the wire is again brought out by punching. If the wire is brought out more laterally than the designated zone (has passed the fracture line), the angle of bending of the guiding end of the wire is decreased. After the wire emerges from the skin at the required point, a threaded stop is screwed onto it (Fig. 2.11.7). If osteoporosis is present an allogenic bone pad of a larger diameter is placed under the stop. An amount of skin equivalent to the stop is dissected away with a scalpel and a canal is formed in the soft tissue with a clip. The stop is plunged as far as the bone by pulling at the opposite end of the axial compression wire. To reduce

244

a

2 Specific Aspects of External Fixation

b

Fig. 2.11.13a,b. CEF of fractures (a) and correcting osteotomies (b) of the femur. When a single-step change in the spatial orientation of the proximal fragment of the femur is impossible or inappropriate, a half-pin is inserted in the neck and connected by hinges to the external supports instead of the half-pin inserted if only the neck-shaft angle is to be corrected; or with forward or backward displacement for changing its ante(retro)version

soft issue trauma, a guide for wires with stops is used (Fig. 2.11.11).A suture is placed on the skin. The second axial compression wire is inserted in a similar way. A transosseous module is then mounted for tensioning the axial compression wires. Two 6-mm halfpins are inserted in the femur connected by the bar IV,8,120; V,8,120 (Fig. 2.11.13a). By means of the distraction clip the axial compression wire is tensioned with a force of 245–294 N, thus creating compression at the junction of the fragments. The technique of CSF in the case of nonunions of the femur generally corresponds to that described for acute trauma.In the case of indications to decortication or osteoplasty, it facilitates control over the insertion of axial compression wires. The axial compression wires are tensioned with a force of 294–343 N. If deformities of the proximal part of the femur are present, insertion of the axial compression wire must be preceded by a correcting osteotomy with singlestep placement of the fragments in the necessary positions. For convenience of the manipulations, the halfpin I,9,90 is inserted. It is also used (instead of an awl) as the counter-stop in axial compression wire insertion through the proximal fragment.After tensioning of the wire the half-pin I,9,90 is connected to the basic device (Fig. 2.11.13b). A wire module basis on two supports VI,9-3; VI,8-2 – VII,3-9 can be used as the transosseous subsystem for tensioning the axial compression wire.

Fig. 2.11.14. Scheme for CSF of fractures of the distal femur

In CSF for repair of the epicondylar region of the femur, a frontal radiograph of the injured bone is used to determine the parameters for insertion of the axial compression wires. Both wires are inserted from the side of the external cortical plate. Working with the device shown in Fig.2.11.3,the angle and insertion level of the proximal wire to ensure its curved passage through the medullary cavity such that it exits at the top of the external epicondyle are determined. The angle and level for insertion of the second wire are determined experimentally and must allow its emergence from the medial cortical plate 1–2 cm proximally from the level of the injury (fracture, osteotomy) of the femur. The operation starts with insertion of both wires to the bone injury level. After reduction or correcting osteotomy, the fragments are stabilized by diafixation. Using the punching technique, the proximal axial compression wire is inserted through the distal fragment until it penetrates the skin in the area of the external epicondyle. The second wire is rotated by 180◦ and is also inserted by punching through the distal fragment until it perforates the skin in the area of the internal epicondyle. It is permissible to insert the second wire by means of a drill from the side of the internal epicondyle. Stops are screwed onto the distal ends of the wires and inserted as far as the bone. Both axial compression wires are tensioned with a force of 196–294 N in the transosseous module III,9,70; IV,9,70 (Fig. 2.11.14).

2.11.4

Tibia

CSF is used in cases when it is possible to ensure an end stop at the junction of the bone fragments. Thus, the indications for CSF in cases of injury to the tibial bone are:

2.11 Combined Strained Fixation of the Long Bones

Fig. 2.11.15. Scheme for CSF of fractures of the distal third of the tibia

1. Transverse and short oblique diaphyseal and metadiaphyseal fractures (injuries 42-A3.3, 43-A1.3 according to the AO/ASIF classification). 2. Slowly setting fractures and nonunions of the mentioned locations with a transverse line of injury or a line close to it with preservation of the coaxiality of the bone fragments or the possibility of its single-step restoration. 3. Correcting osteotomy after which an end stop between the fragments (transverse, hinge, angular etc.) can be created. Axial compression wires for fixation of the tibia are inserted from the external and internal sides of the lower leg (Fig. 2.11.15). To determine the parameters of insertion of every wire, a frontal radiograph is used. After identification of the contour of the internal cortical plate, the size and shape of the medullary cavity is modelled with the plates of the special device shown in Fig. 2.11.3. The optimal angle of insertion of the axial compression wires for fixation of the tibia is in the range 40–40◦ . By moving the bar of the device and changing the angle of the guide tube, the passage of the wire can be adjusted such that it exits from the medullary cavity at the metaphysis of the distal fragment. The operation starts with closing of the wire inserted from the inside surface. For that purpose the tibial plane which can be well palpated is divided into

245

Fig. 2.11.16. For overweight patients of the “muscular” type when it is necessary to mount a ring support with a diameter of more than 160 mm at level II or III, we use the CSF variant with insertion of both compression wires from the internal side of the segment. The angle and level of insertion of the second compression wire determined experimentally must ensure its deviation from the external cortical plate by 1–2 cm more proximally than the level of injury (fracture, osteotomy) of the tibia. After that by controlled counterbending, the wire is rotated by 180◦ and is also inserted by punching through the distal fragment until it exits the skin in front of the external ankle. Both compression wires are tensioned in a module based on the half-pins: II,9,90; III,9,70

three equal parts. The axial compression wire is inserted at the level of the middle and posterior parts strictly in the frontal plane (not perpendicular to the tibial plane!). The second wire is inserted from the side of the external cortical plane in a similar way. In fractures the fragments are reduced by one of the known techniques and two diafixing wires is inserted. A comparison radiograph is obtained to determine the quality of reduction of the fragments and the wire orientation. If during the fixation of a false joint, there are indications to decortication or osteoplasty, this facilitates control over ACW insertion. The wires are inserted, also by punching, such that they exit from the internal and external aspects of the segment, respectively. The stops are inserted as far as the bone and the free ends of the wires are tensioned with a force of 294–343 N (30–35 kgf) in the ring support II,3-9; II,4-10; III,12,70 (Fig. 2.11.15).

246

2.11.5

2 Specific Aspects of External Fixation

Forearm

CSF is used when it is possible to ensure an end stop at the junction of the bone fragments. Thus, the indications for CSF in injuries of the humerus and forearm are: 1. Transverse and short oblique fractures of the diaphyses and metadiaphyses of the ulna and radius (22-A1.2, 22-A2.2), including Monteggia (22-A1.3) and Galeazzi (22-A2.3) fractures. 2. Slowly setting fractures and nonunions of the mentioned locations with a transverse line of injury or a line close to it with preservation of coaxiality of the bone fragments or the possibility for its single-step restoration. 3. The dislocation of traumatic deformities can be eliminated in a single step before fixation. 4. Segmental diaphyseal and metadiaphyseal, and joint defects of the forearm bones – for transplants fixation. In false joints, insertion of the axial compression wire should not be attempted before restoration of the patency of the medullary cavity.

2.11.5.1 Ulna For repair of injury to the ulnar diaphysis the axial compression wire is inserted in the posterior aspect of the distal fragment and exits through the top of the posterior aspect of the olecranon. To determine the angle and level for insertion of the wire, a lateral radiograph is used. Using the device shown in Fig. 2.11.3 the trajectory of the axial compression wire is determined such that the fracture is located between the location of the wire stop on the anterior cortical plate and the point at which the wire emerges from the posterior cortical plate (Fig. 2.11.4). The optimal angle of insertion of the wire for fixation of the ulna is in the range 150–155◦ to the anatomical axis of the distal fragment (the angle is proximally open). The narrower the medullary cavity, the lower the wire insertion angle. The operation starts with insertion of the axial compression wire using a special guide (Figs. 2.11.5 and 2.11.9) into the medullary cavity and its insertion by punching as far as the level of the bone injury. It is important to note that for formation of the canal at the determined level, the reamer must perforate the skin slightly more distally to take account of the thickness of the soft tissue. The axial compression wire is inserted into the canal. At the guiding end of the wire a ski-shaped bend of 170–175◦ and 2–3 mm long must be formed together with an opposite bend at the other end of the wire.

Fig. 2.11.17. In CSF of the forearm bones, the wire is inserted by punching to ensure its progressive motion and it then returns due to its bend to the cortical plate on same the side as it was inserted. Therefore, first, the angle of insertion of the axial compression wire must be minimal, i.e. up to 30◦ in CSF of the radius, and more than 150◦ in fixation of the ulna (the angle proximally open, and second, the bone destruction zone must be located between the compression wire stop on the opposite cortical plate and the point of its return to the cortical plate on the side it was inserted (the interval L). Nonobservance of this condition will result in the wire penetrating between bone fragments during surgery

The wire is gripped with ﬂat-nosed pliers 30–50 mm from the skin and is inserted by hammer taps on the pliers to the level of the bone injury, with the guiding end of the wire being oriented to the posterior aspect of the forearm. As the wire is inserted through the medullary cavity, the pliers are moved away from the skin. In fractures of the ulna, the fragments are reduced by closed manual reduction, by means of reduction plates, or by open reduction with the minimum approach. In Monteggia fractures, the head of the radius is reduced after repositioning the ulnar fragments, and the wire (I,11-5)I,11-5 is inserted for temporary immobilization of the proximal radioulnar joint and tensioned in the support used for tensioning the axial compression wire. Half-pin (I,10,90) can be used instead of wire (I,11-5)I,11-5. If external fixation for a false joint is combined with a decortication operation, after restoration of the patency of the medullary canal, plasty according to the method of Albi-Khakhutov facilitates control over insertion of the axial compression wire. If the ends of the bone fragments are exposed the axial compression wire is inserted retrogradely. For that purpose a wire with a ski-shaped bend at its end is inserted in the distal fragment and placed on a holding device. The wire is inserted by punching and its exit is oriented towards the posterior aspect of the bone in the area of the styloid process. An axial compression wire is also inserted by punching through the medullary cavity of the central fragment, its exit oriented towards the top of the olecranon. During open interventions the wire can be inserted through the central fragment using a low-speed drill. Before perforation of the skin with the wire, the forearm is placed in ﬂexion at 120–130◦. A threaded stop is screwed onto the peripheral end of the wire

2.11 Combined Strained Fixation of the Long Bones

247

Fig. 2.11.18. The variant of tensioning the compression wire based on the 5-mm halfpin I,6,40 is preferred in patients with a large volume of soft tissue, a bone diameter at the level of insertion of the half-pin of not less than 20 mm and without marked osteoporosis

Fig. 2.11.19. The axial compression wire can be tensioned by means of a transosseous module based on wires. Two wires with stoppers, I,4-10 and II,10-4, are inserted at the level of the base of the ulnar process and 50–60 mm distal from it in a plane close to the frontal plane in the opposite direction. The wires are tensioned in the original external support or in a support based on a half-ring lengthened by connection plates. The free ends of the connection plates are joined with a rod

(Fig. 2.11.7) or a stop is formed in the shape of a hook or spiral in the case of osteoporosis.The stop is inserted as far as the bone by pulling on the central end of the wire through an incision/puncture in the soft tissue. A transosseous module is then installed for tensioning the axial compression wire (Figs. 2.11.18–2.11.20). The wire is tensioned with a force of 245–294 N (25–30 kgf)

Fig. 2.11.20. In Monteggia injuries the radius is abducted and the wire (VIII,1-7) is inserted through its distal metaphysis and is tensioned in the ring support. This support is connected by two rods to the transosseous module for compression wire tensioning. The distal support is moved the necessary distance by distraction and after radiographic confirmation that the joint surfaces are at the same level, the wire with a stop (I,11-5)I,11-5 is inserted. If displacement is edgewise, the use of wire (I,3-9) or (I,9-3) can be recommended. The stop eliminates the edgewise displacement of the proximal part of the radius. Then the wire is bent backwards and inwards. The dislocation is eliminated by simultaneous traction at both ends of the wire. After this manipulation wire (I,3-9) is replaced by wire (I,11-5)I,11-5 at the halfpin I,9,90. Another wire is inserted VIII,6-12(VIII,6-12) through both bones at the level of their distal metaphysis. Six weeks later the distal support and the transosseous element inserted at the first level in the radial bone are removed

for fractures and 343–393 N for false joints, and is fixed to the support with a traction clip. In defect diastases with anatomical shortening of the ulna, the first stage involves restoration of the proper relations in the distal radioulnar joint with the help of external distraction fixation and then the ulna is lengthened by 3–4 mm. The device is then dismantled with the exception of wireVIII,6-12(VIII,6-12).The forearm is fixed in a plaster splint. In 7–14 days, if there are no clinical or laboratory signs of inﬂammation, osteoplastic substitution of the defect is performed. In

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2 Specific Aspects of External Fixation

defect diastases without anatomical shortening of the ulna, this surgical treatment stage is not required. The operation starts with visual evaluation of the ends of the fragments. Using the available configuration, they are treated so that there the end stop with the transplant can exit with minimum damage to the bone tissue. If the prominences of the receiving bed interpenetrate with the transplant the rotational rigidity of fixation and the surface area of contact are increased, promoting earlier engraftment and remodelling of the transplant. The medullary cavity is restored. An axial compression wire is inserted in the medullary cavity of the bone fragment orthogradely or retroretrogradely. The defect length is carefully measured. For defects of up to 40 mm, a free autograft from the wing of the ilium is used. The graft must be 3–5 mm larger than the size of the defect and must exceed the ulna diameter by 3–4 mm. A 2-mm canal is made in the projection of the anatomical axis of the transplant. Instead of an autograft it is possible to use ceramic or porous titanium nickelide, or other, bone-replacement materials. For defects of more than 40–50 mm in length, a vascularized autograft from the fibula should be used. The length of a cortical autograft must be 2–3 mm more than the length of the defect. Wire VIII,5-11 is inserted through the ulna and fixed into the half-ring. By pulling the wire the distance between the bone fragments can be increased to allow more convenient introduction of the autograft. The axial compression wire is inserted through the transplant and the proximal fragment. The half-ring is dismantled. The subsequent stages of the operation are similar to those for fractures of the ulna. The compression wire is tensioned with a force of 294–343 N. If the bone replacement of the defect is performed during the second stage of the operation, the device is installed according to the configuration shown in Fig. 2.11.20 after restoration of the length of the ulna. 2.11.5.2 Radius The axial compression wire is inserted into the radial bone from the external or anteroexternal aspect of the proximal fragment. As the wire will be in a plane close to the frontal plane, the calculations must be based on a frontal (anteroposterior) radiograph. The level of the bone injury must be between the axial compression wire stop on the internal cortical plate and the point of its return to the external cortical plate (Fig. 2.11.4). The optimal the angle of insertion of the axial compression wire for fixation of the ulna is in the range 25–30◦ to the anatomical axis of the proximal fragment (the angle is proximally open). The narrower the medullary cavity, the larger the angle of insertion of the axial compression wire.

The operation starts with insertion of the axial compression wire using the special guide (Fig. 2.11.9) into the medullary cavity and its insertion by punching to the level of the bone injury. It is important to note that during formation of the canal at the determined level, the reamer must perforate the skin slightly more proximally to take account of the thickness of the soft tissue. The wire is inserted into the canal, its guiding end having a formed ski-shaped bend of 170–175◦ and 2–3 mm long and an opposite bend in the same plane at the other end of the wire. The wire is gripped with ﬂat-nose pliers 30–50 mm from the skin and the wire is inserted by hammer taps to the pliers to the level of the bone injury, its guiding end being oriented to the posterior aspect of the forearm. As the wire is inserted into the medullary cavity the pliers are moved away from the skin. In fractures of the radius, the bone fragments are reduced using reduction plates or under visual control from the minimum operation approach. If the fixation of a false joint is combined with a decortication operation, after restoration of the patency of the medullary canal, plasty according to the method of Albi-Khakhutov facilitates control over insertion of the axial compression wire. Insertion of the axial compression wire should not be attempted before restoration of the patency of the medullary cavity. In open operations the proximal edge of the skin wound is cut back 2.5–3 cm from the level of bone destruction, a canal is formed, and the axial compression wire is inserted into the medullary cavity under visual control. The axial compression wire is inserted by punching through the medullary cavity of the distal fragment orienting its exit towards the top of the styloid process. Before the skin is penetrated by the wire, the hand is placed in ulnar deviation of 25–30◦ . If the wire has penetrated the skin in the wrist projection, the bend at its guiding end is increased by 3–5◦ , the wire is inserted to the level of the distal metaphysis of the radius and is again distally inserted by punching. A threaded stop is screwed onto the central end of the wire (Fig. 2.11.7) or a stop is formed in the shape of a hook or spiral in the case of osteoporosis. The stop is inserted as far as the bone by pulling the peripheral end of the wire through an incision puncture in the soft tissue. The transosseous module is then constructed for tensioning the wire (Figs. 2.11.21–2.11.23).The axial compression wire is tensioned with a force of 245–294 N (25–30 kgf) for fractures and 343–393 N for false joints and is fixed to the support using a traction clip. The protocol for CSF of defect diastases of the radius is generally identical to that described for defects of the radius. If required, proper relationships are restored in the radioulnar joints during the first stage by external fixation. The axial compression wire is in-

2.11 Combined Strained Fixation of the Long Bones

Fig. 2.11.21. The axial compression wire can be tensioned by a transosseous module based on the 5-mm half-pin VIII,12,120 or three 2-mm console wires

Fig. 2.11.22. If osteoporosis is present, the transosseous module is mounted by means of two wires tensioned in the lengthened half-ring VII,1-7; VIII,7-1

serted in the medullary cavity under visual control moving the soft tissue in the proximal direction. If osteoplastic replacement of the defect is performed as the second stage, the axial compression wire is tensioned in the ring supports shown in Fig. 2.11.23. In defect diastases without anatomical shortening of the radius the module for tensioning the compression wire

249

Fig. 2.11.23. The CSF of Galeazzi fractures is basically performed using a method similar to that described for isolated fractures of the radial bone. The ring support is used for tensioning the basic wires. After reduction and stabilization of the bone fragments, proper relationships are usually restored in the distal radioulnar joint. For its temporary immobilization the stabilization wire with a stop VIII,6-12(VIII,6-12) is inserted through the distal metaphysis of the forearm bones

is mounted as for fractures and false joints of the radius (Figs. 2.11.21 and 2.11.22). 2.11.5.3 Both Forearm Bones (Combinative Fixation)6 In general, CSF essentially involves the identification of the parameters for compression wire insertion, and their insertion through both bone fragments. The fixation in the transosseous modules does not differ from that designated in the sections devoted to fixation of isolated injuries of the ulna and radius bones. Combined fixation of injury to both bones of the forearm can be performed if indications for the CSF of the ulna or radius are present. If the injury is such that an end stop cannot be provided, the splinters of the paired bone are stabilized using a transosseous or an implanted fastener. In oblique diaphyseal fractures, plates, intramedullary nails, or titanium nickelide fasteners are used. In splinter injuries or already compromised osteogenesis (nonunions, false joints), external fixation is used. The most appropriate installations for combination fixation of forearm fractures are shown in Figs.2.11.24– 2.11.26. The of combination fixation operation always starts with CSF. The axial compression wire is tensioned only after reduction of the fragments of the paired bone. 6

The definition of combinative fixation is given in section 1.7.

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2 Specific Aspects of External Fixation

Fig.2.11.24. In CSF of both bones of the forearm, the operation starts with insertion of an axial compression wire through the radius. After that an axial compression wire is inserted through the fragments of the ulna. Then modules for compression wire tensioning are mounted. The modules are connected by two rods. The compression wire is tensioned after the fragments of both bones of the forearm have been adapted. The force compression by the connection rods must match the tensioning force of the axial compression wires. Three or four weeks prior to the planned date of removing the device, the rods connecting the modules for compression wire tensioning are removed, which allows the patient to begin developing rotational movements

Fig. 2.11.25a,b. A mandatory condition in using implants in combinative fixation is the possibility of ensuring “stablefunctional” (not requiring the plaster bandage) fixation, which allows restoration of all kinds of movements in adjacent joints, including rotation

a

b

2.11 Combined Strained Fixation of the Long Bones

251

Fig. 2.11.26a,b. In a combination of CSF of the radius with external fixation of the fragments of the ulna (a) to ensure rotational function, reference positions designated in the atlas with the sign “→” are used for insertion of transosseous elements in the ulna. In the case of oblique, spiral or splintered destruction of the radius and transverse destruction of the ulna, combinative fixation will involve the use of fewer transosseous elements than external fixation, and will ensure the optimal biomechanics of fixation of every forearm bone (b)

a

2.11.6

b

Clavicle

Structurally the clavicle is a spongy bone since its internal lumen is filled with cellular bone and there is no intermedullary canal. Our research [71] has shown that an axial wire in the spongy bone provides sufficient rigidity for fixation of splinters, even in cases of minimum axial compression, preventing displacement both in transverse and short oblique fractures (91.2-A3 type according to the AO-ASIF classification) and oblique (91.2-A2), spiral (91.2-A1) and splintered (91.2-B1, 91.2-B2) fractures. Moreover, indications for CSF are nonunions and segmental defects of the clavicle (for bone graft fixation). The axial compression wire in CSF of the clavicle is inserted through both fragments retrogradely with the

help of a drill. Therefore, each end of the wire must be provided with a triquetral grind. Where the wire penetrates the cortical plate of the bone fragments depends on the fracture level (Fig. 2.11.27). Regional anaesthesia or sedation is generally used for CSF of the clavicle. The operation is performed with the patient lying supine with a cushion along C7– D7 and the arm behind the back on the side of the injury. The patient’s head is turned in the direction opposite to the injured clavicle. In successfully closed reduction of fractures, CSF of nonunions without angular deformity with displacement of fragments along the periphery, the axial compression wire is inserted closed orthogradely from the side of the central fragment. In open reductions, after separation of the bone

Fig. 2.11.27. Scheme for insertion of axial compression wires in fractures of the internal third (a), middle third (b), and external third (c) of the clavicle

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2 Specific Aspects of External Fixation

Fig. 2.11.28. In fractures a bayonet-shaped stop is formed at the central end of the axial compression wire and inserted as far as the bone. The remaining part of the wire is bent at an angle of 90◦ and cut off 1–1.5 cm from the surface of the skin, which facilitates its later removal. A console wire of diameter 2–2.5 mm with a stopper is inserted in the acromial process of the scapula and a connection plate from the Ilizarov device is used as a module for tensioning and fixation of the axial wire

a

b

Fig. 2.11.29a,b. Schemes for CSF in diaphyseal fractures, false joints (a) and defects of the sternal extremity (b) of the clavicle. It is important to note that the basic wires seldom appear in the plane of the support as shown in the schemes. The 1-3 ends of the wires are usually fixed with posts. Both basic wires can be inserted through the acromial process of the scapula: acr.,7-1;acr.,11-5. After mounting the external support and tensioning of the compression wire, the skin around the wires is examined, and if skin tension is present, the skin is released and sutured

fragments, the direction of wire insertion into the fragments is marked with an awl on the side of the bone wound. The central splinter is deﬂected backwards and the wire is inserted using a drill until it appears above the skin and then further until it stops preventing adaptation of the fragments. For short (20–30 mm) central fragments the axial compression wire is inserted through the fragment by punching. A bend of 165–170◦ is formed in the central end of the wire and an opposite bend at the other end for orientation control. The wire is inserted in the prepared canal, gripped with ﬂat-nosed pliers and pushed using hammer taps orienting the exit to the anterior surface of the clavicle (sternum). After penetrating the skin the ends of the wire are straightened (Fig. 2.11.28). The operation to replace a clavicle defect starts with visual evaluation of the ends of the fragments.Using the available configuration, they are treated so that the end stop with the transplant can exit with minimum damage to the bone tissue. It should be born in mind that if prominences of the receiving bed interpenetrate with

the transplant the surface area of contact is increased promoting a higher stability of fixation. Especially important is their presence at the junction of the transplant with the central fragment as the largest displacing forces arise here. After reduction the axial compression wire is inserted using a drill through the peripheral fragment until it appears above the skin. In fixation of nonunions and defects of the sternum, and when a longer fixation period is considered necessary, a stop is screwed on the central end of the axial compression wire (a bend stop is formed) and the wire is inserted as far as the bone. The wound is drained and sutured. The module for tensioning the axial compression wire is then installed. The coracoid process of the scapula is located by palpation and a wire is inserted in its base so that its guiding end is oriented in the direction of the spine of the scapula. We stress that first the direction of insertion of the wire is established, and only then is the skin pierced with it. If after insertion of the wire along the

2.11 Combined Strained Fixation of the Long Bones

base of the coracoid process–spine of the scapula axis the soft tissue under the wire appears to be compressed, the wire must be extracted and inserted at a different angle. Only then is the wire fixed in the chuck of the drill and inserted until its guiding end lies in the projection of the spine of the scapula. The second basic wire must be provided with a stop. It is inserted through the acromial process of the scapula (peripheral fragment of the scapula) in the back to front direction. The external support is consists of a half-ring and connection plates. It is placed at an angle of 120–130◦ to the anatomical axis of the shoulder so that it will not further prevent abduction in the humeral joint. The distance between the support and the skin surface at the front should be at least 1.5 cm and the distance at the back should be 2 cm. Only then are the basic wires tensioned simultaneously (Fig. 2.11.29). The axial compression wires should be tensioned in the external support with a force of 176.4–196 N (18–20 kg). 2.11.6.1 External Fixation of the Clavicle A pioneer in the development of external fixation of fractures and dislocations of the clavicle was Sushko [72]. The recommendations for the method published by the Russian Ilizarov Research Center [73] form the basis of the requirements of the method of fixation that are generally still applicable: 1. At least two 2-mm console wires at an angle to each other are inserted in each bone fragment. 2. The points of insertion of the wires must be near the epiphyses of the clavicle. 3. The points of insertion of the wires must be on the upper surface of the clavicle. 4. The direction of wire insertion must coincide with the anatomical axis of the bone fragments. 5. With diaphyseal fractures wires are inserted through both cortical layers. 6. With fracture-dislocations of the acromial end of the clavicle the console wires are inserted in the acromial end of the clavicle only as far as the opposite cortical layer; console wires are not inserted in the acromial process of the scapula but rather Kirschner wire acr.,6-12 is used, its ends bent in a U-shape towards each other. 7. The minimum distance between the skin surface and the external supports must be in the range 1.5– 2 cm. Indications for external fixation are: fractures of various severity levels (91.2-A, 91.2-B, 91.2-C according to the AO/ASIF classification), fractures joining with an improper position of the bone fragments, fracturedislocations and dislocations of the acromial end of the clavicle. False joints and clavicle defects are better treated with CSF.

253

When an original device of Sushko is not available, the fixation frame can be assembled from the parts of an Ilizarov device. This will require two plates (direct or radius), posts, wire fixators and a connection rod; 3mm half-pins can be used instead of wires. Regional anaesthesia or sedation is generally used. The operation is performed with the patient supine with a cushion along C7–D7 and the forearm behind the back. The patient’s head is turned in the direction opposite to the injured clavicle but it should not be thrown back; the side of the face must be level with the anterior aspect of the chest. First, all the points for insertion of the wires are determined from radiographs in two projections. Radiopaque markers are placed 2 cm from the joint surfaces of the acromial and sternal extremities of the clavicle perpendicular to the anatomical axes of the bone fragments. Injection needles are also placed to mark the anterior and posterior boundaries of the bone fragments at the levels of insertion of the transosseous elements. Mounting of the device starts from the medial support. The wires are fixed in the extreme holes of the connection plate by hand using wire fixators, so that their guiding ends only slightly protrude over the edge of the plate. The plate is applied onto the skin and the wire directed towards the sternal extremity of the clavicle and inserted by hand to the bone. One should again make sure that the wire is located from the upper aspect of the clavicle and in the centre of the bone diameter.A reference point is marked on the wire showing the depth of its insertion indicating the depth at which it will exit from the lower cortical plate.The wire is drilled at low speed monitoring its insertion depth. The bar is then moved away from the skin by 1.5–2 cm. The second wire is then inserted until it touches the bone and, after making sure that it is located in the centre of the clavicle diameter, the first wire is fixed rigidly to the support.After the second wire is inserted and fixed, the support is similarly mounted on the peripheral fragment.

2.11.7

Postoperative Protocol

The principles of the postoperative management of patients with external fixation are given in section 2.17. The specific features of CSF are provided in this additional section. In the operating room after the tensioning the axial compression wires, the skin around the wires is examined. If the skin is compressed, either in the neutral position of the extremity or during passive movements, the skin and if necessary the fascia are dissected and sutured. A pressure bandage in the form of a sling is applied to the area of the axial compression wire inser-

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2 Specific Aspects of External Fixation

Fig. 2.11.30. In dislocations of the acromial end of the clavicle, the operation described by Ilizarov and Barabash starts with mounting of the transosseous module based on one (shown) or two wires (Fig. 2.11.29). The clavicle is then reduced by single-stage manual reduction and is held with a single-tooth hook. A wire is inserted in the acromial process of the scapula from its posteroexternal surface upwards. The guiding end of the wire is oriented to the upper surface of the acromial extremity of the clavicle. A stop is formed at the central extremity of the wire and inserted as far as the bone. The wire is tensioned in the external support with a force of 147–176 N. In chronic injuries (“nonreducible” dislocations) the joint surfaces are openly aligned. When indicated ligamentoplasty is also performed

Fig. 2.11.31. A possible approach is to use console wires with stops. After both transosseous modules have been mounted, the fragments are reduced either in a single step in acute trauma or over a certain time in badly joined fractures. In both cases the modules fixing the bone fragments are mutually displaced (Fig. 1.6.4–1.6.8)

tion for 2–3 hours (Fig. 2.6.5). The wires exit points are covered with gauze dressings soaked in 70% ethyl alcohol. During the first 3–4 days the dressings are changed daily then as required, but no less frequently than every 7–10 days. The places of the ACW exit are to be daily checked thoroughly. After CSF of the femur, the patient is placed on the bed and a soft cushion is placed under the knee joint to ensure leg ﬂexion of 80–100◦. After fixation of the clavicle or the humerus, wedge-shaped cushion is placed between the shoulder and the body to abduct the extremity by 45◦ . Active–passive movements in the adjacent joints and gentle massage are prescribed from the second day after the operation. At 5–12 days the patients are managed as outpatients.With clinical and radiographic monitoring, the load on the extremity is increased and to 70–85% of the functional norm by the end of the fixation period. In elderly patients with weak muscles of the shoulder and forearm subluxation of the head of the humerus can occur following CSF. To prevent this complication, we recommend use of a cravat bandage for 1–2 weeks and measures to strengthen the shoulder girdle muscles. Throughout the fixation period (not less than every 1.5–2 weeks) the tensioning of the axial compression wires is monitored by a calibrated spring or wire

fixator. Interfragmental compression is reduced by 30– 50% from the initial value over the 2 weeks prior to the planned dismantling of the structure and tension is completely removed 5–7 days prior to dismantling. We stress that the fixation schedule is established individually from the dynamic results of the clinical and parallel radiographic monitoring. For example, normal skin colour, no soft tissue oedema, painless movement in adjacent joints are negative indications for restoration of the mechanical strength of the bone, and conversely lack of discontinuity of the shadow of the periosteal regenerate, and a changing radiological picture even with the preserved tracked space between the fragments are indications for completion of the fixation period. In fractures of the diaphysis and metadiaphysis of the femur/tibia the structure is generally dismantled within 7–12 weeks, in corrective osteotomies within 6– 9 weeks, in fractures of the diaphysis of the humerus within 6–7 weeks, in fractures of the metaphysis and metadiaphysis of the humerus within 4–6 weeks, after CSF of false joints within 8–10 weeks, after CSF of fractures of the clavicle within 3.5–5 weeks, and after corrective fixation of orthopaedic pathology within 11–14 weeks. The CSF structure is dismantled in the outpatient setting. Local infiltration anaesthesia is combined with the administration of promedol (trimeperidine), Relanium (diazepam) or Dimedrol (diphenhydramine).

2.11

Combined Strained Fixation of the Long Bones

255

Fig. 2.11.32. In fractures and dislocations of the acromial end of the clavicle, the medial support is assembled at the level of the internal third of the clavicle. An external support is mounted based on wire “acr.,6-12”, and its ends are immediately bent above the skin towards each other at an angle of 80–90◦ . A moderate distraction force is applied. A console wire with a stop is then inserted into the acromial end of the clavicle downwards. To avoid cutting during fixation of chronic injuries, a flexural stop of diameter 5–6 mm is used. In chronic injuries this wire is fixed to the external support by a traction clip

Fig. 2.11.33. According to the method of Barabash [90] the basic support is mounted in a similar manner to that used in CSF (Fig. 2.11.29). A console wire with a stop is then inserted into the acromial end of the clavicle. The wire is fixed to the basic support by posts and a distraction clip

First the transosseous module for tensioning the axial compression wires is dismantled. To remove the compression wires from the humerus or femur, the extremity is adducted to the maximum.The tensioning ends of the compression wires are thoroughly treated with an antiseptic. The wire is gripped with sterile ﬂat-nosed pliers and pushed proximally with a hammer until the stops appear under the skin. The skin is punctured and the stops are released and unscrewed (or cut off). The

wires are extracted by pulling at the opposite end. The skin is sutured. If it becomes necessary to remove a compression wire early, for example due to soft-tissue inﬂammation not controlled by conservative measures, first a transosseous module is mounted on the opposite bone fragment and connected by connection rods to the wire tensioning module then the wire is screwed out of the threaded stop with moderate pulling and is removed.

256

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2 Specific Aspects of External Fixation

Pelvic Injuries7

2.12.1 Insertion of Transosseous Elements into the Pelvic Bones In external fixation of the pelvis (Figs. 2.12.1–2.12.31), 2-mm wires with a stop and wires without a stop are used as well as console transosseous elements comprising console wires and half-pins of 5- and 6-mm diameter with a spongy thread. The use of half-pins with a cone-shaped cutting end and limiting stay nuts enhances the strength of the bone–metal block. Prior to insertion of the half-pins into the bone, an hole is made with a stiletto in the adjacent cortical plate. We recommend using half-pins having a 4-mm screw part and a shank end provided with an M6 thread [74]. When using it, the tail is inserted 10–20 mm into the bone (Figs. 2.12.4 and 2.12.5). This approach is equivalent to using a half-pin with stepwise change in diameter. This enables the length of the pin in the bone to be increased, which also enhances its stability. Determination of the positions for insertion of the transosseous elements through the pelvis is based upon two main requirements: safety of the major vessels, nerves and intrapelvic structures,and the optimal morphometric parameters (width,height,length,bone density) for maintenance of strong fixation of the wires and half-pins. However, as indicated in section 1.6, for determination of the optimal positions for insertion of transosseous elements (the reference positions), displacement of soft tissue in relation to the bone during movement of the adjacent joints must be taken into consideration. Positions with minimal displacement of soft tissue are associated with a lower risk of pin-induced joint stiffness and pin-tract infections. As reference positions for the pelvis have not yet been determined, the “available positions” are presented below using the terminology presented in section 1.9 [1,75–86].The figure legends give the angles of deviation of the tail of the transosseous elements relative to the sagittal plane of the body. However,it is necessary to bear in mind that the recommendations given in the literature concerning angles of insertion of the transosseous elements relative to the “human body axis” are based on the anatomictopographic characteristics of the intact pelvis so that they would be quite difficult to implement in practice when there are displacement of bone fragments, multiple lesions and obvious oedema of soft tissues, and in obese patients. 7

The material presented was prepared in collaboration with A.V. Runkov.

“Closed” insertion of transosseous elements facilitates the use of: • Probes (needles, wires) to determine the limits of the internal and external cortical plates both at the site of insertion and exit when placing the wires. • Fluoroscopy or X-ray imaging with radioopaque markers. In difficult cases, one should resort to open insertion of the half-pins. An incision should be made in the soft tissues so that the direction of insertion of the transosseous element can be controlled visually. In any case,final radiographic confirmation of the correctness of positioning of the transosseous elements is mandatory. Wires should be inserted through the wing of the ilium (Figs. 2.12.1 and 2.12.2). According to Menshchikova et al. [81], the wires should be inserted not lower than the anterior inferior iliac spine in front, and the posterior inferior iliac spine at the back. For insertion of the half-pins, the crests of the iliac wing, the anterior spines, the supraacetabular area, the pubic bones and the lateral masses of the sacrum should be used (Figs. 2.12.3–2.12.8). As mentioned above, the angle of the iliac wing depends on the character of displacing the pelvis half and the sex of the patient. Therefore an injection needle or a thin wire is inserted along the inner aspect of the ilium (as for an intrapelvic Novocain block) to serve as a marker for determining the plane for insertion of

Fig. 2.12.1. Olive wire 1 is inserted into the anterior-upper spine of the iliac bone. The shank end of the wire is bent internally at an angle of 30–35◦ and distally at an angle of 40– 45◦ . The wire must pass through the thick part of the anterior third of the iliac bone and exit at the junction with the middle part. Wire 2 is inserted somewhat anteriad to the exit point of wire 1, its exit being oriented towards the junction between the middle and posterior thirds of the iliac bone crest. The wire is inserted until its end protrudes 30–40 mm. Then, on the opposite side, next to soft tissues, a corrugated or bayonet-like flexural stop block is formed. The shank end is pulled until the stop block contacts is plunged to the bone

2.12 Pelvic Injuries

257

Fig. 2.12.2. A method for fixing the iliac bone crest using two parallel pairs of wires has been described by Shevtsov and Tropin of the Russian Ilizarov Research Center. Wire 1 is a halfpin inserted into the anterior-upper spine with its exit oriented towards a point situated 3 cm above the posterior third of the posterior-upper spine of the iliac bone wing. Wire 2 is inserted 1.5 cm below and set back from wire 1 and parallel to it. The exit site of wire 2 must be 1.5 cm above the posteriorupper spine. Wire 3 is inserted at the junction between the anterior and middle thirds of the iliac bone crest at an angle of 35–40◦ relative to wire 1 directed towards the posteriorlower spine of the iliac bone. Wire 4 is inserted 1.5 cm cranially from wire 3 and parallel to it with its exit oriented towards the posterior-upper spine. Wires 1 and 4 are inserted at an angle of 25–40◦ (the optimal angle being 28◦) relative to the sagittal plane. For wires 2 and 3 the angle of the bend is 25–35◦ (the optimal angle being 32◦ ). If the bend angle is greater than the recommended range the major vessels may be damaged in the area of the sacroiliac joint. If the bend angle is insufficient, the wires only pass through the anterior half-round of the iliac bone wing [81] Fig. 2.12.3. In the anterior third of the iliac bone crest, halfpins are inserted to a depth of up to 5 cm along the iliac bone wing bending the shank end cranially at an angle of 40–45◦ and laterally at an angle of 30–35◦ . In the middle third of the iliac bone crest, half-pins are inserted to a depth of up to 3.5– 4 cm along the iliac bone wing parallel to the body axis (at an angle of 90◦ relative to the sagittal axis), having bent the shank end laterally at an angle 30–35◦

Fig. 2.12.4a–c. Correct (a) and incorrect (b, c) insertion of the half-pin a

b

c

258

2 Specific Aspects of External Fixation

a

b

c

d

Fig. 2.12.5a-d. Insertion of half-pins into the iliac bone wing. a Landmark for insertion of the awl. b Insertion of a thick awl. c Insertion of a thin awl. d Insertion of a half-pin with two diameters

Fig. 2.12.6. A half-pin is inserted to a depth of 3–3.5 cm into the anterior-upper spine of the iliac bone after bending the shank end internally at an angle of 30–35◦ and distally at an angle of 30–35◦ . A half-pin is inserted to a depth of 3–4 cm Into the anterior-lower spine of the iliac bone having bent its tail at an angle of 8–10◦

the half-pin. The most ventral half-pin is inserted into the ilium wing set back 10 mm from the anterior upper spine. The projection of the external border of the bone diameter can also be shown by a wire or needle marker. Following skin incision, a conical recess is made with the aid of a triangular stiletto of a 5-mm diameter to perforate the upper cortical plate. The awl must be inserted set back from the crest of the inner margin equal to one-third of its thickness (Fig. 2.12.5a). For insertion of a half-pin with stepped diameters, a recess of up to 5 mm is made with a 5-mm awl. Then in the centre of the recess, a canal of 40–50 mm is made using a ﬂexible 2-mm awl inserted parallel to the inner needle marker. While forming the canal with the

awl, some resistance from the bone may be sensed as a slight characteristic crunch which is an indirect sign of absence of perforation of the compact layer. If a dip of the awl is sensed, it should be reinserted. The stepped half-pin is inserted into the formed canal to a depth of 40–50 mm, so that the part of the half-pin of greater diameter enters the bone to a depth of 10– 20 mm (Figs. 2.12.4a and 2.12.5d). Depending on the device assembly, two to five halfpins are inserted into the iliac wing 10–15 mm apart. In the sacrum, the half-pins are inserted to a depth of 1.5 cm into the upper part of the lateral mass at level S1, i.e. directly through the crest of the iliac bone and sacroiliac joint.

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259

a

b

c Fig. 2.12.7a–c. a Half-pins are inserted 1–1.5 cm above the margin of the acetabulum into the supratrochanter area at an angle in the range 10–60◦ relative to the frontal plane. Half-pins are inserted in the horizontal plane 3–5 cm more proximally from the projection of the greater trochanter apex to a depth of 4–5 cm. b, c Insertion of the half-pins into the pubic bone is controlled with the aid of fluoroscopy in two projections. The pin is inserted 5–7 mm from the inner edge of the pubic bone and 5–7 mm from the edge of the pubic joint to a depth of 3–4 cm until it is 2–3 mm beyond the lower edge of the pubic bone

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2 Specific Aspects of External Fixation

Fig. 2.12.8a,b. A needle is inserted into the posterior third of the crest of the iliac bone with the patient lying on his or her side. The posterior-upper spines of the iliac bones are identified by palpation and, at that level, a marker needle is inserted paraosseously along the external cortex in fractures of the lateral mass of the sacrum or along the inner cortex in ruptures of the sacroiliac joint. A channel in then formed parallel to the needle into which a half-pin is inserted until it exits beyond the edge of the iliac bone. Up to three half-pins may be inserted from the posterior-upper to posterior-lower spine of the iliac bone

a

b

2.12.2 Principles of Assembly of External Devices for Fixation of Pelvic Injuries For osteosynthesis of the pelvis, open (arched, anterior frame) and closed (circular) devices have become the most widely used. The biomechanical properties of semicircular devices (Figs. 2.12.12–2.12.14) are similar to those of arched devices, but they are more cumbersome. The external device is assembled from the parts of the standard Ilizarov kit (section 1.4).To reduce the separate components of an injured pelvic ring, the modules fixing bone fragments are mutually displaced. In the arched device, the supports are those of half a femoral arch (Fig. 2.12.9a). Assembly of the external frame and the choice of transosseous elements depend on the clinical objectives and on the type of injury. The use of an isolated assembly of the anterior frame type is ineffective in vertical unstable injuries. In such injuries, the posterior parts can be fixed, for example, in a ring device. In contrast, the use of cumbersome circular devices in unstable rotational pelvic injuries (and even in stable injuries) is inappropriate. The orientation of both arched and bow supports is as shown in Fig. 2.12.10. For circular devices, large femoral arches should be used as the external supports. The distance from the skin surface to the frontal support is in the range 2.5–3 cm, and to the rear support 2–3 cm more [78].

2.12.3

Surgical Technique

The details of the intervention depend on the type of pelvic injury and on the general condition of the patient: in unstable vertical injuries and in rotational injuries of the “open book” type, external fixation is one element of the antishock measures. The external fixation is performed under general or regional anaesthesia with the patient supine with the bladder catheterized. A table with a recess is used for applying a ring device.

2.12.4 Osteosynthesis in Stable and Partially Stable Pelvic Injuries In stable pelvic injuries, external fixation is used for fractures of the iliac wing with displacement of the broken fragment, and for injuries involving considerable destruction of the anterior semi-ring; for example, bilateral fractures of both pubic bones and ischial bones (injuries 61-A2 by the AO/ASIF classification) (Figs. 2.12.11–2.12.14). In fractures of the “butterﬂy” type (Fig. 2.12.17a), an anterior frame type is used, and half-pins are inserted into the body of the pubic bones. In the first stage, the iliac wings are separated to form a diastasis at the fracture level (Fig. 2.12.17b). As displacement of the fragment butterﬂy will, as a rule, involve a rotational component as well, the half-pins inserted into

2.12 Pelvic Injuries

261

a

b

Fig. 2.12.9a,b. Arched support (a) and two types of arms (b) for fixing half-pins to it

Fig. 2.12.10. Diagram of the location of the pelvis support relative to bone landmarks

a

c

b

Fig. 2.12.11a–c. a Assembly of an arched external fixation device involves insertion of bilateral half-pins into the anterior third of the iliac bone crest. b, c If necessary, the rigidity can be increased by insertion of additional half-pins into the supraacetabular area and anterior-lower spine of the iliac bone

262

2 Specific Aspects of External Fixation

a

b

Fig.2.12.12a,b. The rigidity of the basic wire arrangement developed at the Russian Ilizarov Research Center with semicircular supports (a) can be increased by insertion of additional half-pins (b). The wires have stoppers situated in a counter direction

Fig. 2.12.13. In this arrangement, through anterior and middle thirds of iliac bone crests, three to five olive wires are inserted to meet each other. The wires are bent in a U shape and attached to the supports [91]

Fig.2.12.14. In this assembly, console wires are inserted into the iliac bone crests to a depth of 1.5 cm. As the wires are bent externally after insertion at right angles, before insertion it is necessary to displace the skin proximally. On each side, no fewer than four wires are inserted. In addition, two to four console olive wires are inserted horizontally into each wing 2–3 cm below the crest. The length of the wire in front of the stop block platform must be no more than 1.5 cm [92]

the pubic bones should be turned anteriad and backward (Fig. 2.12.17c), and then the vertical displacement is eliminated. Then the half-pins in the pubic bones are fixed to the basic supports, the diastasis is eliminated, and the apparatus is stabilized. In partially stable injuries to the pelvic ring, the ligaments of the pelvis posterior segment are partially preserved, the vertical displacement of the pelvic half being absent. In these cases, sufficient stability of the osteosynthesis may be achieved by fixation of the pelvic anterior segments alone. In injuries of the “open book” type, the pelvic half is displaced externally and backwards (Fig. 2.12.18a). The device is assembled with the arches turned to-

wards each other at an angle of 10–15◦, the angle being open cranially (Fig. 2.12.18b). Under ﬂuoroscopic control, a single-step reduction is performed by levelling the support positions relative to each other (Fig. 2.12.18c). In partially stable fractures, lateral compression (61-B2 by the AO/ASIF classification) results in damage the anterior parts of the pelvis in the form of rupture of the pubic joint or fracture of the pubic and ischial bones with the fragments overlapping each other. Persistence of the damaging force results in damage to the lateral mass of the sacrum or a vertical fracture of the posterior segments of the ilium. The ligaments of the sacroiliac joint will remain intact whereas

2.12 Pelvic Injuries

a

c

263

b

Fig. 2.12.15a–c. A posterior reduction node is assembled in the circular assembly for elimination of displacements in the dorsal parts of the pelvis in vertical unstable injuries

Fig. 2.12.16. In this assembly, the circular apparatus is assembled with four arches connected to each other with repositioning nodes. This makes it possible to control the position of pelvic bones attached to them and to perform precise gradual dynamic reduction. In the course of treatment, part of the apparatus may be removed, generally the posterior arches. Such modular transformation (by analogy with external fixation of long bones) enables the size of the assembly, and therefore also the discomfort for the patient, to be minimized

half of the pelvis will be displaced inward and backward. The total volume of the pelvis will not increase (Fig. 2.12.19a). In the first stage, supports should be applied to the iliac wings positioning them at angle in the range 10– 15◦ , the angle being opened caudally. Then the pelvic wings are moved apart 2–3 cm (Fig. 2.12.19b), and the semibow supports are positioned using threaded bars. Reduction of the fragments now occurs (Fig. 2.12.19b). The apparatus is stabilized.

2.12.5 Osteosynthesis in Vertical Unstable Pelvic Injuries Injuries of the 61-C type are characterized by the vertical displacement of one half or both halves of the pelvis, i.e. the injuries are rotationally and vertically unstable. Anteriorly symphysis rupture, fracture of the anterior and lower branches of one or both pubic bones or fracture of both branches and rupture of the symphysis may occur. Posteriorly the iliac fracture (61-C1.1), dis-

264

2 Specific Aspects of External Fixation

a

b

c

Fig. 2.12.17a–c. Scheme for the external fixation of fracture 61-B2.2

a

b

c

Fig. 2.12.18a–c. Scheme for reduction of unilateral injuries to the pelvis of the “open book” type: 61-B1

a

b

c

Fig. 2.12.19a–c. Scheme for reduction of unilateral injuries to the pelvis of the “lateral compression” type: 61-B2

Fig. 2.12.20. Add-on device for attachment of the apparatus to the operation table comprises two bars (1, 2) and connecting half-pins (3). Bar 1 is attached to the operation table, half-pins 3 are connected to the apparatus external support, and bar 2 is moved relative to the latter [86]

2.12 Pelvic Injuries

a

b

c

d

e

f

265

Fig. 2.12.21a–g. Scheme for external fixation of injury 61-C1 g

location or fracture-dislocation of the sacroiliac joint (61-C1.2), or fracture of the sacrum (61-C1.3) may occur. A rotationally unstable injury on one side and on the other – a vertically unstable injury – is classified as 61-C2. A bilateral vertical unstable injury, the most complex injury, is classified as 61-C3. These injuries are accompanied by stretching or rupture of the sacral plexus roots, and damage to the pelvic diaphragm, bladder, vagina and rectum. Fixation and repositioning of the anterior pelvic segments alone in this kind of injury will not restore the anatomical interrelationships in the posterior segments of the pelvic ring and neither will it provide sufficient stability for early mobilization of the patient. Successful treatment of these injuries involves early repositioning and fixation of the posterior parts of the pelvis. In unilateral injuries (Fig. 2.12.21a), skeletal traction is applied in order to reduce the displacement of the injured half of the pelvis. An anterior frame de-

vice is then applied and the pelvis is stabilized in this newly achieved position (Fig. 2.12.21b, c). The patient is then turned on his or her side. The arch of the anterior semiframe must be located in the recess of the orthopaedic table. Anterior and posterior semibow devices are connected to form a circular pelvic support. Into each posterior third of the iliac crests, a half-pin is inserted. In obese patients and in considerable displacements up to three half-pins can be inserted on each side in the space between the posterior-upper and the posterior-lower spines of the ilium. The half-pins are attached by arms to the respective supports of the device. The posterior supports should be connected to each other by plates and threaded bars enabling further correction of any remaining displacement of the pelvis. First the supports should be moved apart until a diastasis is obtained (Fig. 2.12.21d), then the injured half of the pelvis is brought down in the vertical and anteroposterior direction (Fig. 2.12.21e). Radiographs

266

2 Specific Aspects of External Fixation

in two planes are obtained, and then the posterior and anterior parts of the pelvis are brought together (Fig. 2.12.21f). After reduction, supportive compression is applied to the posterior and anterior semiring devices (Fig. 2.12.21g). If both sacroiliac joints are damaged, half-pins are inserted into the sacrum lateral masses of the sacrum. If bone needs to be lowered, for example the left half of the pelvis, then reduction is facilitated by attaching the support mounted on the right half of the pelvis to the operation table with a special add-on device (Fig. 2.12.20). Reduction of acute injuries, except fractures of the second or third zone of the sacrum (transforaminal or midline), is completed on the operation table. Singlestep reduction, either manually or with a device, is dangerous because it may cause or exacerbate neurological symptoms involving the roots of the lumbosacral plexus [84]. Reduction using a device may be considered satisfactory if: • The remaining displacement in the posterior parts is not more than 0.5 cm. • The remaining displacement in the anterior parts is not more than 1.5 cm,including displacement at the level of the pubic joint which should not be more than 1 cm. • Asymmetry of the hip joints relative to the sacrum should not exceed 2 cm. In addition, the indications for the need to correct an existing deformity include the presence of any type of the pelvic ring instability. Therefore, if only the anterior pelvis is injured (61-B1.1) or if injury to the posterior pelvis is insignificant (61-B1.2), arched and semiring devices should be used. Biomechanical studies have shown that devices of this type do not prevent pathological mobility of the sacroiliac joint [84].Therefore, semiring devices can only be used in injuries with insignificant displacement of the posterior pelvis (61B1.3, 61-B2). If reduction fails or if fixation is insufficient fixation (pain syndrome), a posterior reductionfixation device is used. In vertical unstable injuries (61-C), only ring devices should be used. In addition, the greater the time since the injury, the greater must be the rigidity of the assembly. To achieve this, additional wires and halfpins should be used in the assembly. Reduction of vertical unstable injuries should be performed gradually and in the following order: 1. Diastasis is created in the posterior segments. 2. Vertical (usually cranial) displacement of posterior segments is eliminated. 3. Displacement in the sagittal plane (anteroposterior) is eliminated.

4. Displacement in the anterior pelvic segments (usually rotational) is eliminated. 5. Diastasis in the posterior segments is eliminated. 6. The apparatus is stabilized.

2.12.6 External Fixation of Fractures of the Acetabulum As an urgent osteosynthesis or for transport immobilization, the simplest apparatus is used (autonomous skeletal traction) as shown in Figs. 2.12.22 and 2.14.12. In the first stage, the pelvic ring configuration is restored by moving the pelvic half-supports relative to each other in accordance with the procedures described above. Closed reduction of the fracture is performed under the ﬂuoroscopic or radiographic control. Reduction of the acetabulum fragments in simple fractures in which there is one large fragment is achieved by traction on the respective part of the hip joint capsule by pulling the femur (Fig. 2.12.23). In displacements of the acetabulum posterior column, traction is applied in the position of maximal internal rotation. In displacements of the anterior column, the hip is maximally abducted with up to 90◦ of ﬂexion and maximally rotated outwards. In complex fractures with displacement of dissociated posterior and anterior columns (T-form and two-column frac-

Fig. 2.12.22. Scheme for reduction of central dislocations of the hip

2.12 Pelvic Injuries

267

a

b

tures), successive repositioning and fixation of the acetabulum columns is performed. First, with the aid of half-pins and traction on the hip the anterior column is reset and fixed, and then the direction of traction is changed to reset the posterior column. In fractures of the anterior column of the acetabulum, the fracture line may have spread to the iliac wing. In these cases, two half-pins are inserted into the intact parts of the ilium near the sacrum. The fragment of the anterior column is separately fixed after a preliminary repositioning (Fig. 2.12.24). To transfer the reduction force directly onto the fragment, the head of the femur and the displaced fragment of the acetabulum are attached to each other with wires to form a single block. A half-pin is inserted into the acetabulum and temporary reduction is achieved by moving the femur/fragment block in the necessary direction. After reduction has been achieved, the fragments are fixed to each other with half-pins, wires and

Fig.2.12.23a,b. Scheme for reduction of transverse fractures of the acetabulum and ruptures of the sacroiliac and pubic joints (posterior repositioning node is not shown)

screw inserted under ﬂuoroscopic control through a small incision. Then the repositioning wires are removed and the hip is put into the physiologically neutral position (Fig. 2.12.25), i.e. 20◦ of ﬂexion in the hip joint, 0◦ of abduction and rotation. The operation is completed by releasing the soft tissues around the transosseous elements: the skin is incised, displaced relative to the wires (or half-pins), and then resutured. When it is impossible to perform full fixation, e.g. in the event of mass admission of casualties, or because of the seriousness of the condition of the victim, the “fixation” variant of external fixation is performed (Fig. 2.12.11). In injuries to the anterior and posterior pelvis, this fixation should be used in combination with conservative treatment approaches: lying by Volkovich,“hammock”, skeletal traction. In the second stage, either the device is disassembled or implantation osteosynthesis is performed.

268

a

a

2 Specific Aspects of External Fixation

Fig. 2.12.24a,b. Schemes for reduction of high (a) and low (b) fractures of the acetabulum anterior column

b

b

c

Fig. 2.12.25a–c Scheme for repositioning acetabulum fragments with a “single-block” external fixation device. a, b Prior to and after manipulation; c internal fixation of the fracture with a screw inserted transcutaneously

2.12.7

Postoperative Recommendations

Following osteosynthesis of the pelvis with ring devices, a special trolley and bed with a recess for the assembly are required.If the assembly consists of anterior half-rings alone, there are no special recommendations for lying. The bed must allow the patient access to personal items, must allow the prophylaxis of bed sores, and must be equipped with a Balkan frame to which the assembly can be temporarily attached with damper springs to enable comfortable therapeutic physical exercise. If in very unstable injuries (61-C3) the assembly did not include the insertion of half-pins into the posterior lower spine or the sacrum, then in order to avoid secondary displacement of the pelvis it is necessary to apply skeletal traction via the femoral condyles [84].

Maintenance of the transosseous elements should be performed in the same way as for the Ilizarov apparatus. Dressings are changed using antiseptic agents daily during the first 2 weeks and then once a week. Any remaining displacement of fragments is eliminated starting on the 2nd or 3rd day after the operation at a rate of 1 to 4 mm per day (0.25–1 mm four times daily). The patient starts mobilization as the pain reduces, and in relation to the seriousness of the injury and stability of the fixation. Mobilization can start on the second day in simple injuries, and by the end of the third week in serious injuries. First the patient is encouraged to sit, and then to walk with crutches. If repositioning of the displaced bone is good and the fixation is sufficiently rigid, the patient should be able to walk

2.12 Pelvic Injuries

Types of disorder of the posterior parts Unilateral

Bilateral Simple

Combined

Vertical-rotational Vertical Stable

Unstable

painlessly with a walking stick in 1.5–2 months. The time until movement training of the hip joint in fractures of the acetabulum can be started depends on the character of the injuries and the completeness of the surgical restoration of the joint anatomy. In full reduction with stable fixation of the acetabulum fragments with a pelvic support and half-pins, movement training can be started after removal of the femur support 3 or 4 weeks after device installation. The time for fixation of pelvic fractures is 6 to 8 weeks. In “clean” ruptures of the joint with no internal fixation, the device is disassembled not before 3 months. On the planned day for removal of the assembly, a functional test is performed. The reduction nodes are removed or loosened, and the patient is asked to walk with a full load for 0.5 to 1 hour. If there is no pain and the halves of the pelvis show no mobility, the assembly is removed. Following disassembly, crutches (or a walking stick) are recommended again for walking. If there is no pain, weight-bearing should be increased to the functional load within 3 weeks. Partial weightbearing of the extremity operated upon in fractures of the acetabulum should take place not before 3 months after osteosynthesis, and full weight-bearing not before 4 months. Clinical restoration of the pelvic anatomy is confirmed radiographically. The appropriateness of using support belts, braces or bandages is addressed on an individual basis.

2.12.8 External Fixation of Malunited Pelvic Fractures In patients with traumatic deformities of the pelvis, particular attention should be paid not only to their orthopaedic status but also to their neurological and urogenital status. It is advisable to find out the reason for any pain or inability to weight-bear, and to take the patient’s wishes into consideration [87]. Instability of the pelvic ring can be determined clinically by pressing upon the pelvis wings in different directions.It is important that the instability is confirmed by functional radiographic tests, which include standing in turn on each leg, or lying with the legs apart with weights attached and bent at the knees and hips. Relative movement of the pelvic halves of over 5 mm indicates instability of the pelvic ring. To precisely identify the character of the deformity and the grade of adhesion of the bone fragments ra-

Rotational Stable

Unstable

269

Table 2.2. Classification of pelvic posttraumatic deformities [88] (grades of hip joint displacement: I, asymmetry of the hip joints up to 1 cm or no asymmetry; II, asymmetry of 1–2 cm; III, asymmetry of over 2 cm)

diographically, images are obtained in the frontal and internal oblique planes (Fig. 2.12.26). The condition of the anterior pelvis can be determined using routine radiographic imaging, but in the posterior pelvis a tomographic study may be necessary to more precisely determine the location of the injury, the direction of the displacement, and the presence or absence of bone union. The direction of the displacement of the pelvic half indicates whether the deformity is vertical or rotational (Table 2.2). Rotational deformity implies a change in shape of the pelvic ring as a result of rotational displacement of the innominate bone relative to the sacrum in one of the three planes; for example, an old rupture of the sacroiliac joint and pubic joint following injury of the “open book” type. Vertical deformity implies a change in shape of the pelvic ring when, along with rotation, there is cranial displacement of one of the innominate bones at the level of the posterior pelvis; for example,an incorrectly consolidated fracture of the sacrum lateral masses with cranial displacement of the pelvis half, or an ipsilateral false joint of the pubis and ischium. The degree of pathological mobility of the pelvic halves can indicate whether a deformity is stable or unstable. Instability may be associated with rupture of joints, false joints of the innominate bone and the sacrum as well as with incomplete consolidation of incorrectly consolidated fractures within 6–8 weeks of the injury. The indications for surgical treatment in old injuries include: 1. Vertical deformities of the pelvis of grade II or III irrespective of the stability grade. 2. Unstable rotational deformities of the pelvis of grade II or III. 3. Stable rotational deformities of the pelvis of grade III. The aim of surgical treatment is to eliminate asymmetry of the hip joints and to stabilize the pelvic ring in the correct position. If the deformity is evaluated as stable then the application of the device is preceded by osteotomy. As a rule, an unstable deformity requires an additional stage of open intervention in the zone of poor consolidation after correction in the device, especially when the deformity includes old ruptures of joints. In rotational deformities, the asymmetry of the hip joints does not,as a rule,exceed 2 cm and the instability

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2 Specific Aspects of External Fixation

a

b

Fig. 2.12.26a,b. Radiographic imaging of the pelvis: frontal projection (a) and internal oblique projection (b)

most often is associated with an old rupture of the pubic joint or incomplete consolidation of the fragments in the anterior pelvis. This makes closed elimination of the pelvic deformity possible by means of a slight turn of the half pelvis in the device at the level of the sacroiliac joint. In vertical deformities, the asymmetry of the hip joints often exceeds 2 cm and is due not only to rotation of the innominate bone but also to cranial displacement of the posterior pelvis. Therefore, restoration of the extremity length by correction of the half pelvis only might prove ineffective without also correcting the displacement of the posterior pelvis. Hence elimination of asymmetries of less than 2 cm is possible by correction of the rotational displacement of the innominate bone, and in greater asymmetries by correction of the vertical displacement of the posterior half pelvis. Stable vertical deformities can be corrected with the aid of osteotomy of the lateral mass of the sacrum laterally relative to the sacrum foramens and the pubis and ischium. In unstable injuries, the osteotomy of the posterior segments may be omitted if there is an obvious (over 5 mm) vertical mobility in

the pelvis posterior segments confirmed by functional testing. Surgical treatment is performed in several steps. In unstable deformities of the pelvis, the first step involves closed restoration of the shape of the pelvic ring with the aid of an external fixation device. The assemblies recommended for analogous fresh injuries must include reinforced reductional nodes and additional half-pins. Rotational deformities of the pelvis result from rotational unstable fractures of the pelvic ring as well as from vertical unstable fractures of the pelvis if, during treatment, the cranial displacement of the half pelvis was eliminated.Furthermore,the innominate bone may also be rotated inward or outward (in the horizontal plane) in ﬂexion (basket handle type injury: rotation in the sagittal plane) or abduction or adduction (rotation in the frontal plane) relative to the sacrum. The actual position will be a combination of these various types of displacement, but it is always possible to determine the most obvious components of the deformity in order to successively eliminate them.

2.12 Pelvic Injuries

Fig. 2.12.27. Reduction node for reduction of rotational deformities of the pelvis

The external supports of the device should be positioned in hypercorrection relative to the present displacement of the half pelvis, and then connected to each other with a repositioning node in order to eliminate the rotational displacement in the sagittal plane which makes it possible to eliminate the inequality in leg length (Fig. 2.12.27). Displacement of the pelvis half will start on the second day after the operation at the rate of 1 mm four times a day at the same time as mobilization of the patient without loading the injured side. Therapeutic exercises are prescribed and physiotherapy if there is pain. After bringing down the anterior parts of the pelvis as confirmed by serial radiographs, the repositioning node is reassembled to bring the parts together and to provide compression in the horizontal plane. Having eliminated the deformity, the supports of the anterior and posterior parts are rigidly connected thus enabling full loading of both lower extremities. In old ruptures of the pubic joint, its synthesis is achieved using a tendon allograft or a plate, without disassembling the external fixation device. If there is limited contact between the pubis and ischium, osteosynthesis is achieved using a plate. The fixation device must remain in place for not less than 3 months after the final stabilization of the fragments until consolidation is confirmed radiographically. In unstable vertical deformities of the pelvis, the integrity of the posterior bone–ligament complex is completely destroyed. There is a vertical displacement

271

of the pelvic half ring with stretching or rupture of the sacral plexus roots. In the absence of obvious vertical mobility of cranially displaced posterior parts of the pelvis, in the first stage, osteotomy of the sacrum is performed (see the technique for this operation below), and half-pins are inserted into the posterior spines of the iliac bones. The patient is then turned on his or her side and halfpins are inserted into the anterior parts of the pelvis. The supports of the device are installed with hypercorrection relative to the present displacement of the half pelvis half,and then they are attached to each other with reduction nodes in the front and in back for creation of a diastasis in the osteotomy area. If vertical mobility is present in the posterior parts then osteotomy is not required. Gradual distraction at a rate of 1 mm four times a day is started after elimination of pain on the 3rd to 5th day at the same time as mobilization of the patient without loading the injured side. Therapeutic exercises and physiotherapy are prescribed. If obvious pain or signs of irritation of segments S1–S3 roots develop, it is necessary to reduce the rate of displacement to 1 mm per day or temporarily halt the distraction. Traction of the posterior parts is performed until a diastasis of 10–15 mm is produced. In the next stage the posterior reduction node is pulled into a vertical position for gradual elimination of the cranial displacement of the half pelvis. The distraction rate is 0.25 mm four times a day (Fig. 2.12.28). Following the vertical alignment of the posterior ilium relative to the sacrum, if necessary the anteroposterior displacement is eliminated (Fig. 2.12.29). The final stage of correction involving the anterior repositioning node is elimination of the remaining rotational displacement as described above. Compression is applied between the fragments, while the device is stabilized (Fig. 2.12.30). Internal fixation of the pubic bones and symphysis is achieved using plates. Final stabilization of the position achieved is maintained by forming an ileosacral block with one or two compressing screws inserted under ﬂuoroscopic control via the ilium into the sacrum. Partial weight-bearing on the injured side is permitted after completion of all the interventions, gradually bringing it up to full weight-bearing within a month. The fixation device must remain in place for not less than 3 months after final stabilization of the fragments until consolidation is confirmed radiographically following clinical testing. In stable deformities, the surgery proceeds in three stages: 1. Mobilizing osteotomy in the areas of incorrect consolidation.

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2 Specific Aspects of External Fixation

Fig. 2.12.28. Scheme for elimination of cranial displacement

Fig. 2.12.29. Scheme for elimination of anterior-posterior displacement

Fig. 2.12.30. Scheme for creation of compression between fragments after elimination of rotational displacements

2.12 Pelvic Injuries

2. Gradual correction of existing displacements using an external fixation device. 3. Internal fixation. For osteotomy of the anterior pelvis and lateral areas of the sacrum, the open method is applied or a minimally invasive approach is under ﬂuoroscopic control. Before osteotomy the device is installed or, as a minimum, the transosseous elements are inserted. Osteotomy of the sacrum is performed with the patient lying prone. Under the ﬂuoroscopic control in two planes X-ray contrast marks (injection needles) are inserted to mark the upper and lower margins of the lateral mass of the sacrum, and the incision line is drawn with the aid of the marks. An incision of 3–5 cm is made parallel to the posterior spines of the ilium 0.5– 1 cm inwards. The posterior upper aspect of the lateral mass of the sacrum is exposed by blunt and acute dissection. At the front and back the elevators/protectors are established and between them under radiographic control in two planes osteotomy of the sacrum is performed using a chisel lateral to the sacral foramina. The chisel must not exit onto the anterior aspect of the sacrum. Finally, clear mobility of the dissociated fragments must be achieved. The wound is sutured layer by layer. Osteotomy of the ischium is performed with the patient lying prone. The ischial tuberosity is found by palpation. An incision of 1–2 cm is made along the gluteal fold 1 or 2 cm medially from the ischial tuberosity apex. The ascending branch of the ischium is isolated by blunt dissection. Osteotomy is performed medial to the ischial tuberosity for 1–2 cm. The wound is sutured. Osteotomy of the pubis is performed with the patient lying supine with a catheter in the bladder. An incision of 1–2 cm is made 2–3 cm lateral to the symphysis over the horizontal branch of the pubis. Its anterior upper aspect is exposed by blunt and acute dissection. Osteotomy is performed with a chisel under the protection of elevators inserted along the anterior and posterior aspects of the pubic bone. The wound is sutured. In stable vertical deformities of the pelvis, immobility of the cranially displaced half of the pelvis is due to incorrect consolidation both in the anterior and in posterior pelvis.In some cases,in spite of consolidation of the anterior pelvis and absence of clinical or radiographic signs of instability of the pelvic ring, there is a false joint of the lateral mass of the sacrum that can be revealed only by tomography. In order to eliminate this type of deformity, osteotomy is necessary not only of the sacrum, but also of the pubis and ischium, generally on the side of the greater displacement.

273

The operation is performed in three steps under general anaesthesia on an X-ray-negative operation table using ﬂuoroscopy. In the first step, with the patient supine, osteotomy of the pubic bone is done. The second step involves turning the patient to the prone position for successive osteotomy of the ischium and the lateral mass of the sacrum. Once clear mobility of the half pelvis been achieved, half-pins are inserted into the posterior spines of the iliac bones. In the third step, with the patient lying supine and a recess at the level of the pelvis, half-pins are inserted into the anterior parts of the innominate bones, and the device is assembled. Assembly of the device, the beginning and rate of distraction, the order of elimination of the displacements, the final stabilization of the pelvic ring with internal half-pins, and the time the device remains in place are analogous to those for stable vertical deformities. The device is removed when there is radiographic evidence of consolidation and after clinical testing. Internal fixation of the bones and joints is performed using reconstruction plates. The use of allotendoplastics for fixing the pubic symphysis is possible. In old ruptures of the pubic joint, after joining the pubic bones, an ultrasonic examination is necessary as well as examination of the bladder after administration of contrast agent in order to rule out its entrapment. After that, osteosynthesis is performed with the immersed constructions (plates, implants with shape memory). The device is not disassembled and the fixation is continued for 4–6 weeks more. One of the most difficult tasks in the treatment of the patients with posttraumatic deformities of the pelvis is the elimination of pathological mobility of the posterior segments that can occur at the sacral level, or at the level of the sacroiliac joint or the iliac bone. If there is a malunion or a nonunion of the ilium, osteosynthesis is done with plates and screws. In instability at the level of the sacroiliac joint or lateral mass of the sacrum, an ileosacral block is formed by insertion of compressing screw via the iliac bone and sacroiliac joint into the body of the first or second sacral vertebra. This operation is performed at the final stage of the treatment when all the displacements have been eliminated with the aid of the external fixation device. This operation is carried out with the patient lying supine on an X-ray-negative table with a recess for the ring support of the apparatus. Under general anaesthesia, under ﬂuoroscopic control in two projections, and with the aid of a preliminarily inserted guide-wire, the place for insertion of the half-pin is determined. The wire should be oriented perpendicularly to the sacroiliac joint,stay outside the projections of the sacral foramina and not exit beyond the limits of the contour of the sacral vertebrae.

274

2 Specific Aspects of External Fixation

Fig. 2.12.31. Scheme of ileosacral blocking with a compression screw

The location of the incision is situated 1–2 cm distal from a position at the border of the middle and lower thirds of the line connecting the anterior upper and posterior upper spines of the iliac bone. Through an incision of 10–15 mm, using a protector, a canal is formed parallel to the guide-wire using a chisel, and into this canal a compressing spongy screw of 6.5 mm diameter is inserted (Fig. 2.12.31). The wound is sutured. The use of cannulation spongy screws considerably facilitates the performance of this task. The device is removed not before 3–4 months after correction irrespective of the type of deformity. Radiographic evidence of bone consolidation in the pelvis as well as positive results of functional testing are mandatory. It is important to note that, in old ruptures of the joints, loss of reduction will occur even after prolonged fixation after removal of the constructions. Therefore it is recommended that internal fixation be performed after achieving the reduction. In analogous way, internal fixation should be done in situations of probable nonunion at the fracture level, i.e. in the presence of a considerable diastasis or a longstanding nonunion.

ing and facilitates nursing care particularly in patients with polytrauma including the foot. It provides efficient fracture stabilization and the possibility of indirect fracture or fracture-dislocation reduction based on the principle of ligamentotaxis. It can be used as a temporary foot-stabilizing device in compound fractures until the condition of soft tissue allows major reconstructive procedures to be performed [89]. In the presence of acute or chronic foot infections, Ilizarov external fixation may be the ultimate way of stabilizing an infected fracture or nonunion, as the pins are inserted away from the infection focus. Ilizarov external fixation is a versatile system with different components that allows a specific frame configuration to be constructed for reduction and stabilization of a particular fracture type in a particular part of the foot. The following sections illustrate various external fixator configurations employed for the treatment of different types of foot injury and deformity. Important features of surgical technique are described in a comprehensive step-by-step manner.

2.13.1

2.13

Foot

In this section we discuss the treatment of forefoot, midfoot and hindfoot injuries by the Ilizarov external fixation technique. The importance of anatomic reconstruction of the injured foot must not be underestimated as each of the foot structures plays a unique role in establishing balanced support of the body during ambulation: the hindfoot consisting of the talus and calcaneus converts the rotary tibial forces into foot pronation. Normal gait depends on the normal function of the tarsometatarsal and metatarsophalangeal joints and relationship of individual bones to each other. The Ilizarov external fixation technique,being minimally invasive, does not add any additional surgical insult to the patient. The technique therefore allows control of pain, is associated with decreased bleed-

Forefoot Injuries

Forefoot injuries include phalangeal fractures, fracture-dislocations, fractures of the metatarsals and tarsometatarsal (Lisfranc) joint injuries (Figs. 2.13.1– 2.13.13). Most forefoot injuries are treated conservatively, with a walking cast or hard sole shoe immobilization. Only in injuries with significant fragment displacement are surgical reduction and internal fixation indicated. In old malaligned fractures or fracturedislocations one-stage reduction may be technically difficult due to acquired soft-tissue stiffness or scar tissue formation. Gradual fragment distraction using an Ilizarov external fixator may be the only way of achieving anatomical reduction of the fracture/dislocation.As soon as fragment alignment is corrected, open reduction and internal fixation can be performed as a definitive method.We would recommend external fixation as the method of choice for the treatment of compound fractures or fracture-dislocations, for the treatment of

2.13 Foot

a

b

275

c

Fig. 2.13.1a–c. Longitudinal axial traction is essential for reduction of phalangeal and metatarsal fractures. a, b Traction is applied to a K-wire inserted through the distal phalanx of the toe in the frontal plane. Both ends of the wire are bent 3– 4 mm away from the skin to create a triangle (b). The top of the triangle is formed into a hook where the traction (a) is applied. If radiographs of the foot reveal marked osteoporosis, the K-wire is introduced through the distal phalanx in the sagittal plane (b), with the insertion point 2–3 mm distal from the proximal end of the nailbed in order to prevent migration of the K-wire through the bone. c As an alternative to above technique, traction can be applied using a console wire. Apart from longitudinal axial traction, accurate fragment reduction requires interfragmentary compression. This can be achieved by insertion of additional 3-mm half-pins or console wires into the main fragments of the metatarsal bone

old malaligned fractures and nonreduced old dislocations,and for the correction of various foot deformities. The treatment of phalangeal fractures or fracturedislocations and metatarsal fractures by external fixation begins with insertion of two 1.8–2-mm crossing wires through the calcaneus: calc.,2-8 and calc.,4-10. Both K-wires are fixed to a half-ring support and tightened using wire a tensioning device. A third 1.8–2.0mm wire with a stop is inserted through the proximal metaphysis of metatarsal bones 1 and 5: m/tars.Vm/tars.I. The wire is fixed to a half-ring support and tightened with a wire tensioning device. Half-ring supports are connected to each other using connecting plates. In compound injuries of the foot or the ankle joint area, temporary spanning fixation of the ankle is indicated. This can be done by extending a foot external fixator module to the lower leg. The ring is positioned at level VIII of the lower leg: (VIII,8-2)VIII,8-2; VIII,4-10. This is connected to the foot frame by three rods. In multiple maluniting metatarsal fractures, traction applied to the distal phalanx of the toe is inefficient. In such situations the alignment of the fragments can be corrected only by traction applied directly

to the distal metatarsal bone fragment. A K-wire inserted through the distal metaphysis of the metatarsal bone will provide the required control over the fracture reduction. Unequal longitudinal displacement of the metatarsal bone fragments is not a contraindication for the above technique. Initially the most displaced metatarsal fragment is reduced. As soon as the original length of the bone has been restored, the external fixator is adjusted as required to reduce the adjacent metatarsals. Figure 2.13.2 shows the Ilizarov “miniexternal fixator” used in the treatment of juxtaarticular phalangeal and metatarsal fractures.

2.13.2

Midfoot Injuries

Severely comminuted displaced fractures of the navicular, cuneiform and cuboid bones can cause significant disability. That is why accurate reduction of tarsal bones fractures is essential. External fixation of such types of foot injury based on the principles of gradual distraction and ligamentotaxis allows restoration of the midfoot anatomy and maintenance of the fragments reduction achieved until the bone has healed.

276

2 Specific Aspects of External Fixation

a

b

Fig. 2.13.2a,b. Features of the Ilizarov “miniexternal fixator” which uses 1.8–2.0-mm console wires. For external fixation of metatarsal bone fractures it is recommended three wires are inserted in each fragment; two wires are usually sufficient for fixation of phalangeal fracture [93]

a

b

Fig. 2.13.3a,b. For reduction of dislocations or fracture-dislocations of the tarsometatarsal (Lisfranc) joint (a) K-wires are inserted through the distal metaphysis of the dislocated metatarsals. The K-wires are fixed and tightened in a half-ring support. The divergent type of Lisfranc joint dislocation requires separate fixation of the K-wires which allows adjustment of the amount of axial traction applied to each fragment depending on the displacement. Applied axial traction is helpful for reduction of longitudinal fragment displacement (one-stage reduction in acute injuries and gradual distraction in old injuries). During the later stages the direction of traction is adjusted (medially, laterally, dorsally or in the plantar direction) corresponding to the direction of fragment displacement. The external fixation foot module is adjusted accordingly. b After the desired fragment alignment has been achieved the fragments are stabilized by insertion of additional wires

External fixation of compound tarsal fractures or fracture-dislocations of a tarsometatarsal joint is a valuable technique for foot stabilization, while open reduction and internal fixation maybe associated with a higher risk of postoperative complications related to soft-tissue healing, such as skin necrosis and wound

infection. In neglected cases, when attempted primary reduction has failed, gradual distraction may be the only method to correct fragment alignment n order to restore foot function. Injuries to a tarsometatarsal joint are renowned not only for their association with immediate, often dis-

2.13 Foot

abling, pain and swelling, but also for later problems due to alteration of foot mechanics and degenerative change. If, despite treatment, there is severe loss of foot function as a result of pain, midfoot fusion can be contemplated and performed using the Ilizarov external fixator. Patients with midfoot injury are divided into four groups depending on the time since injury [89]: 1. Acute injury (up to 3 days).Single stage open/closed reduction. 2. Subacute injury (up to 6 weeks). Single stage open/closed reduction using a distraction device. 3. Old injury (up to 8 months). Two-stage procedure: distractor is applied and gradual distraction is continued for 1–3 weeks. As soon as fragment alignment is achieved, open reduction and internal fixation can be performed as a definitive method of fracture fixation. 4. Old injury (more than 8 months). Advanced posttraumatic degenerative changes of the midtarsal or tarsometatarsal joints are evident. Reconstructive surgery consists of various corrective osteotomies depending on the type of deformity. Comminuted fractures of the tarsal bones make primary reconstruction of joint surface congruency technically demanding and not always possible. Due to a high incidence of posttraumatic osteoarthritis described for such types of midtarsal and tarsometatarsal fractures, primary arthrodesis may be advisable. It is essential to restore and maintain the lengths of the lateral and medial foot columns in order to prevent planovalgus/varus deformity.The gap between the fragments is filled with autogenous cancellous bone graft. Extension of foot external fixation module to the lower leg is not compulsory although it provides more control over foot position, avoiding the need for permanent foot support. Two 1.8–2.00-mm Kwires are inserted through the tibia at level VIII: (VIII,8-2)VIII,8-2; VIII,4-10. These are then connected to the ring support, and the support is connected to the foot module by three threaded rods. Fractures of the navicular, cuneiform and cuboid bones can be treated by external fixation. Two crossing 1.8–2-mm K-wires are inserted through the calcaneus. The wires are tightened with a wire tensioning device and fixed in a half-ring support: calc., 2-8; calc.,4-10. A third wire is inserted through the first and second metatarsal bones. A fourth wire is inserted through the third and fifth metatarsal bones. The wires are tightened and fixed to a half-ring support positioned vertically: m/tars.I–m/tars.II; m/tars.V–m/tars.III.The halfring supports are connected to each other with two threaded rods which give the direction of gradual distraction. If accurate fracture reduction and fixation are

277

necessary, additional console wires with stops can be installed. These provide better control of the fragments and more stability to the fixation, particularly in osteoporotic bone fragments. Reduction of Lisfranc joint dislocations or fracturedislocations by external fixation is technically demanding and requires an expert level of surgical skill. Successful anatomical reduction can be compromised by soft-tissue interposition (torn tarsometatarsal ligaments, joint capsule). In such circumstances after fragment distraction is accomplished, open reduction combined with transarticular K-wire fixation is advised [89]. Primary fusion of the tarsometatarsal joint is indicated if articular surface reconstructionis unsuccessful (severely comminuted fracture type). Additional information is provided in section 2.14. The technique for external fixation of posttraumatic foot deformities is discussed in section 2.13.4.

2.13.3

Hindfoot Injuries

2.13.3.1 External Fixation of Talus Fractures Lee and Bashirov [92] recommend starting external fixation of talus fractures with construction of the frame on the distal third of the lower leg. Two ring supports are fixed to the tibia: V,3-9; V,4-10 – (VIII,8-2)VIII,8-2; VIII,4-10 (Fig. 2.13.4). A combination of wires with half-pins on the lower leg allows modification of the lower leg module from two ring supports to one ring without compromising fixation stability: VII,1,120; (VIII,8-2)VIII,8-2; VIII,4-10. After the tibial module has been constructed two 1.8-mm crossing wires are inserted through the calcaneus. The wires are fixed and tightened in the half-ring support. The lower leg ring supports are connected to the hindfoot module by three threaded rods.Under ﬂuoroscopic control distraction is applied to create a 3–4-mm diastasis between the tibia and talus. Reduction of the talar fragments is achieved by distraction combined with manual manoeuvres. As soon as satisfactory reduction is obtained two wires with stops are inserted through the main talar fragments in the frontal plane under ﬂuoroscopic control. Joint distraction is released leaving a gap of 2–3 mm. If indirect closed fracture reduction is unsuccessful, open reduction of the bone fragments is performed and the fragments are fixed with screws. It is advisable to leave the external fixator in place to provide temporary support for the ankle joint. 2.13.3.2 External Fixation of Calcaneal Fractures The procedure begins with construction of the ring support VII,3-9; (VIII,8-2)VIII,8-2; VIII,4-10 on the

278

2 Specific Aspects of External Fixation

Fig. 2.13.4. Frame construction for reduction of talar fractures described by Lee and Bashirov [92]

lower leg (Fig. 2.13.6a). The first wire is inserted through the talus,3-9 in the frontal plane. It is fixed and tightened in an additional three-hole support which is firmly fixed to the ring support. The optimal position for wire insertion is below the tip of the medial malleolus so that it passes through the talus and through the middle of the lateral malleolus. Alternatively the wire can be inserted through both malleoli. A second olive wire is inserted through the metatarsal bones m/tars.V– m/tars.I. It is tensioned and fixed to a half-ring support. The forefoothalf-ring module is connected to the lower leg module using an additional support and a threaded rod of appropriate length. The main (basic) module can be constructed combining wires and half-pins – a hybrid construction: VII,12,120;VIII,9-3; talus,1,90 (Fig. 2.13.6b). A half-pin is inserted into the talus in the oblique-sagittal plane from front to back lateral or medial to the tibial anterior muscle tendon (position 1 or 2), or in the obliquesagittal plane from front to back, from outside inside more lateral than the long extensor muscle of the toes (position 10 or 11) [95]. Then two crossing wires are inserted through the calcaneal tuberosity at an angle of less then 45◦ to the frontal plane. The wires are tensioned and fixed in a two-thirds ring support. External fixation of posttraumatic deformities of the calcaneus can be achieved by applying gradual distraction to the displaced malunited fragments. The frame construction is similar to that described above and is illustrated in Fig. 2.13.7. The proximal and distal wires must be inserted through the calcaneus as far

Fig. 2.13.5. Frame construction for reduction of talar fracture-dislocations described by Shigarev and Zyryanov [94]. The device is based on the principle of “two level distraction” applied to the subtalar and ankle joints combined with manual fragment reduction. The directions of the olive K-wires depend upon the fracture plane and the direction of displacement of the main fragments

apart as possible. Calcaneal osteotomy is performed. Gradual distraction of the fragments should be started after 5–7 days at 0.25 mm three of four times per day. It is mandatory to monitor the condition of the skin throughout the whole period of distraction at the hindfoot area in order to prevent soft tissue related complications. If a primary hindfoot injury has led to the development of posttraumatic ﬂat foot deformity and subtalar joint arthritis then simultaneous correction of the longitudinal arch of the foot can be combined with arthrodesis of the subtalar joint. In order to achieve such a complex goal, the external fixation device is constructed as illustrated in Fig. 2.13.6. Distraction begins three or four days after the operation in the standard protocol (0.25 mm three or four times per day). It is always important to monitor the condition of the soft tissue around the K-wires in order to reduce the risk of pin tract sepsis. After restoration of the longitudinal arch of the foot the distraction process is continued until the subtalar joint gap is 5–7 mm. Simultaneously varus/valgus heel deformity is corrected by applying additional distraction along the medial/lateral hinged connecting rods (as described above). If during distraction the soft tissues around the wires become inﬂamed the distraction should be stopped. The reaction generally subsides within 3– 4 days, and then distraction is resumed. It is recommended that wires be removed from the area of softtissue inﬂammation if antiinﬂammatory treatment is

2.13 Foot

a

279

b

Fig. 2.13.6a,b. A two-thirds ring calcaneal support is connected to the main module by three hinges, two on the medial and lateral aspect of the foot and one in the midline. It is important that the rotational axis of the lateral and medial hinges corresponds to the top of calcaneal deformity (CORA). This assembly allows reduction of any kind of calcaneal fragment displacement. If the fragment is in the varus position, then distraction applied along the medial hinge will reduce the displacement; If the fragment is in the valgus position, gradual distraction is applied along the lateral hinge until the fragment is reduced. For correction of the Bohler angle the distraction is applied along all three hinges. Rotational alignment of the calcaneal fragment can be achieved by changing the position of the hinged connecting rod in the two-thirds ring support

Fig. 2.13.7. It may happen that distraction created along the connecting hinged rods increases the subtalar joint gap so that reduction of the impacted calcaneal fragment fails. In such cases an additional half-ring support is installed. Moderate distraction is applied to the subtalar joint to widen the joint gap and restore the longitudinal arch of the foot. An additional one or two wires are inserted through the impacted calcaneal fragment. The wires are tensioned and fixed to newly added half-ring support. Gradual distraction at a rate of 0.25 mm three or four times a day is applied to the impacted fragment until it is reduced and the Bohler angle is restored [96]

not successful and inserted in an adjacent nonaffected area. Alternatively, half-pins can be used instead of wires: calc.,7,90 or calc.,5,90 [76, 95]. The second stage of the surgical procedure consists of harvesting bone from the iliac wing. The size of the graft should be wider than the subtalar joint gap by 3–5 mm. The subtalar joint is debrided by removal of the degeneratively changed articular surfaces. The bone graft is placed between the calcaneus and the talus vertically as illustrated in Fig. 2.13.8. The external fixation device is adjusted to generate moderate compression between the talus and calcaneus to facilitate reliable graft fixation.

2.13.4

Correction of Foot Deformities

In this section we introduce only the basic principles of foot deformity correction by external fixation. Because of the variety and complexity of congenital and acquired foot deformities it is practically impossible to describe in one section all the methods of foot deformity correction using Ilizarov external fixation. The main idea of presenting this material is therefore to demonstrate that complex foot deformities can be successfully corrected by external fixation techniques developed at the Russian Ilizarov Research Center. Before reading this section, the reader is referred to the previous sections in which the principles of construction of

280

2 Specific Aspects of External Fixation

a

b

Fig. 2.13.8a,b. External fixator for restoration of the longitudinal arch of the foot and subtalar joint fusion

Fig. 2.13.9. External fixator for correction of pes calcaneus is similar to the frame described for equines foot correction. It is important that the axis of the hinged connecting rods corresponds to the talar head centre

external fixation devices for the treatment of foot and ankle joint injuries are introduced. There are eight major kinds of foot deformity [28] that can be united into four pairs (Table 2.3).In practice the various main types of foot deformity are often combined in a complex foot deformity. An example of such a complex combination is club foot deformity where foot equinus is combined with forefoot adduction. Distinguishing the main components of a complex foot

deformity allows proper planning of deformity correction and the construction of appropriate external fixation modules. The main principles of equinus foot deformity correction are discussed in section 2.5.4 (Fig. 2.14.23). The external fixation device for correction of a complex foot deformity is constructed of modules designed to correct the individual components of the deformity. As described above, foot deformity correction

2.13 Foot

a

b

281

Fig. 2.13.10a,b. Excessive forefoot adduction is corrected using two supports. One half-ring support is placed on the hindfoot. Wires are inserted through the calcaneus: calc., 2-8; calc., 4-10. A alternatively instead of the wires a half-pin hybrid configuration can be used: calc.,4-10; calc 7,90. The second halfring support is placed on the forefoot. A Kwire is inserted through the metatarsal bones: m/tars.I–m/tars.V. If the forefoot deformity is relatively mobile then only one K-wire is sufficient to achieve the desired correction. If the forefoot deformity is rigid or the metatarsal bones are osteopenic then two K-wires are inserted: m/tars.I–m/tars.II; m/tars.V–m/tars.III. This provides better control over the forefoot and prevents loosening of the K-wires by allowing a more equal distribution of the distraction force. Hinged connecting rods are attached to each half-ring support (a). b Alternative configuration using two olive wires for the correction of excessive forefoot adduction

Fig. 2.13.11. External fixator for correction of pes cavus consists of two supports. one fixed to the calcaneus and the other to control the forefoot position. Half-ring supports are connected to each other by hinged rods. The rotational axis of the hinges should correspond to the top point of the forefoot deformity

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2 Specific Aspects of External Fixation

Pes equinus

Pes calcaneus

Pes adductus (metatarsus varus)

Pes abductus (metatarsus valgus)

Pes excavatus

Pes planus

Pes supinatus (pes varus)

Pes pronatus (pes valgus)

a

Table 2.3. Main types of foot deformity

b

Fig.2.13.12a,b. External fixator for correction of varus foot deformity. The frame is constructed using two modules, one placed on the distal lower leg and the other mounted on the foot. The ankle joint is stabilized either by a wire 3-9 inserted through the talus in the frontal plane: talus (or through the lateral malleolus) or by a half-pin inserted into the talus: talus,2,90. The transosseous element stabilizing the ankle joint is fixed to the ring support on the lower leg. The foot and lower-leg modules are connected to each other by two threaded rods with hinges (a view from the back). b A similar technique is used for the correction of forefoot supination

Fig. 2.13.13. Simultaneous lengthening of the hindfoot and midfoot [100]. A K-wire is used to stabilize the talus: talus, 3-9. More stable fixation of the intermediate fragment can be achieved using two wires introduced through the talus: talus,1-7 and talus,11-5. The wires are tightened and fixed to the ring support on the lower leg

by external fixation always requires stabilization of the ankle joint by connecting the foot module to the lower leg ring support.

In children, the correction of congenital foot deformity may also require soft-tissue release involving lengthening of the Achilles tendon, plantar fasciotomy

2.14 Large Joint Pathology

or capsulotomies. In adults, correction of foot deformity by external fixation should be followed by footstabilizing procedures (arthrodesis) after the desired correction has been achieved. Otherwise there is a risk of recurrence of the deformity after the external fixation device is removed. That is why the surgery is planned in two stages: initially the foot deformity is corrected, and then the foot is stabilized in a second step. Alternatively the surgery can be planned as a onestage procedure: after removal of wedge or falciform piece of bone (according to the method of Kuslik) the external fixation device can be used to stabilize the fragments or for the gradual correction of the residual deformity. In clinical practice methods for changing the shape of all parts of the foot based on the gradual distraction of bone fragments to induce new bone formation in the osteotomy zone are widely used [97–100]. Figure 2.13.13 shows a scheme for changing the foot shape and size through formation of a distraction regenerates after V-shaped osteotomy.

2.14

283

the half-ring: acr.,7-1; acr.,11-5. Additional stability for the support is provided by insertion of a half-pin into the scapular spine. For this the anterior and posterior cortical plates of the scapular spine are marked by two needles.A canal is made with an awl between them and the half-pin is inserted in it to a depth of 35–45 mm. It is possible to use a support based on two half-pins inserted in the scapular spine [3]. Wires VII,9-3 and VII,10-4 are then inserted through the humerus and fixed after tensioning to the ring support. In anterior dislocations a half-pin II,8,70 with a spongy thread is inserted. In inferior dislocations half-pin II,9,70 is inserted, and in posterior dislocations half-pin II,10,70. In the presence of marked osteoporosis or if the dislocation occurred more than 4–5 months previously an additional half-pin is inserted at the level III. The supports are connected by three bars. At this stage the half-pin remains unfixed to the supports of the device (Fig. 2.14.1). For compression arthrodesis of the shoulder joint the position of the patient on the operating table de-

Large Joint Pathology

In its general form the external fixation device used for treatment of large joints pathology includes: 1. A transosseous module fixing the proximal joint segment. 2. A transosseous module fixing the distal joint segment. 3. A hinge subsystem connecting the transosseous modules. In each case the assembly of each component of the device has its own specific features.

2.14.1

Shoulder

In this section we consider the fundamentals of external fixation of chronic dislocations of the shoulder joint and arthrodesis of the shoulder joint (Figs.2.14.1– 2.14.4). External fixation of chronic dislocations of the shoulder involves three stages [101]: 1. Abduction of the head under the edge of the glenoid cavity of the scapula by means of axial distraction. 2. Adduction of the head outwards. 3. Approximation of the joint surfaces. The operation is performed with the patient supine with a cushion throughout C7-D7. The glenohumeral joint must project beyond the operating table. Two wires are inserted through the acromial process and scapular spine and are fixed after tensioning to

Fig. 2.14.1. Distraction between external supports starts on the 3rd to the 5th day at a rate of 1.5–2 mm per day in six to eight stages. The distraction rate is decreased and the number of stages increased if pain or neurotrophic disturbance occurs. Correct insertion of wires VII,9-3 and VII,10-4 (i.e. perpendicular to the anatomical axis of the fragment) helps to bring the proximal part of the humerus outwards during distraction. Depending on the duration of the dislocation and rigidity of the soft tissue this stage takes from 5 to 18 days

284

2 Specific Aspects of External Fixation

Fig. 2.14.2. After radiographic confirmation of abduction of the rim of the head of the humerus by 3–5 mm more caudally than the lower edge of the fossa glenoidale the device is removed. For this purpose a long connection plate with threaded ends is installed between the external supports near the half-pin. To exclude further rotation of the connection plate due to pulling of the half-pin a stabilizing derotational unit is mounted on its distal end by connection plates with posts. The free end of the half-pin is connected to the connection plate so that it can be pull at an angle of 110– 115◦ to it (the angle is proximally open) as shown in the diagram, rather than perpendicular to the anatomical axis of the humerus. Insertion of a half-pin at an angle of 70–75◦ and the application of a traction force at an angle of 110–115◦ to the anatomical axis of the humerus decreases the risk of forcing out the half-pin and ensures better biomechanics of adduction of the proximal part of the humerus outwards. Traction at the half-pin is performed at a rate of 0.25 mm four to six times a day. The direction of the angular transposition of the humerus is monitored radiographically: only outwards, outwards and forward, outwards and backwards are allowed. This stage usually takes from 3 to 8 days

pends on the approach planned for removal of the joint surfaces: supine with a cushion between the scapulas and the shoulder girdle projecting beyond the table edge, or on the healthy side [102]. The synovial membrane is not excised, the cartilage on the head of the humerus is removed only in where it contacts the glenoid cavity of the scapula. The shoulder should be

Fig. 2.14.3. After radiographic confirmation of adduction of the proximal humerus outwards, gradual closure of the external supports is started for final reduction of the dislocation. After 4 weeks of fixation the device is removed and restoration of movement in the shoulder joint starts

placed in the position of abduction of 60◦ , anterior deviation of 30◦ and inward rotation of 15◦ [103]. In order to increase the area of contact between the scapula and humerus it is also possible to use elements of the operations of Goht, Watson-Jones, Movshovich and others. The most important part of compression arthrodesis is identification of the vector of the compression force at which the head of the humerus will not slide from the joint surface of the scapula. A wire is then inserted through the head of the humerus in the centre of the fossa glenoidale in a direction strictly coinciding with the optimal direction of the compression force. One or two more diafixing wires are inserted for the convenience of installing the device. Two crossing wires are inserted through the neck of the scapula, 1,5–2 cm below the top of the coracoid process. One of must pass through the scapular spine, the second one under the scapular spine. The external support (lengthened half-ring or arc) is installed on the shoulder girdle so that: • It is located perpendicular to the wire inserted in the plane of the compression force vector. • The wires cross at the centre of the support.

2.14 Large Joint Pathology

285

Fig. 2.14.4. The external supports of the girdle and shoulder are positioned perpendicular to the compression force vector at which only mutual compression of the surfaces occurs, i.e. the shoulder does not slide relative to the scapula. Alignment of the direction of the compression force and a straight line connecting (conventional) points of decussation of the basic transosseous elements is also beneficial. A clinical test (compression of an unsutured operative wound) ensures correct installation of the device from a biomechanical point of view

Only then are the wires tensioned and fixed to the support. As the half-ring is not parallel to the insertion plane of the wires, fixation clamps are used for their fixation. Additional rigidity is provided by one or two half-pins inserted into the scapular spine. The transosseous module is then mounted on the shoulder: IV,8-2; V,10,70. This ring support is also placed perpendicular to the wire inserted in the plane of the compression force vector. The humerus must be located in the centre of the ring. Both supports are connected by three or four threaded rods that are strictly parallel to the wire inserted in the plane of the compression force vector. After the operation the arm is placed on an abduction splint or two telescopic half-pins connected to a broad belt are fixed to the distal support of the device. Supporting compression is applied at a rate of 1 mm every 10–14 days.Ankylosis usually emerges 2.5– 3 months after the operation.

2.14.2

Elbow

In this section we consider the fundamentals of external fixation of chronic dislocations of the forearm, elbow joint stiffness, and arthrodesis of the elbow joint (Figs. 2.14.5–2.14.8). The first stage of the closed reduction of chronic dislocations of the forearm involves installation of a double-support module based on a ring and a twothirds ring on the shoulder. The support is based on wires (Fig. 2.14.5a) or may be a hybrid device (Fig. 2.14.5b). The second module fixing the forearm can also be a wire or hybrid wire/half-pin device: II,6,90; III,9-3; IV,6,90 (as shown in the figure) or III,9-3; IV,6,70. A hinge-distraction subsystem is mounted between the modules. After reduction of the dislocation the elbow joint is fixed in the mid-physiological posi-

tion for 2–3 weeks, after which the device can be used for development of movement in the elbow joint. One of the conditions for successful external fixation for stiffness in the elbow joint is to use the reference positions shown in the atlas for insertion of transosseous elements. Thus, the device shown in Fig. 2.14.5b is recommended. Figure 2.14.6 shows the assembly developed at the Russian Ilizarov Research Center [104]. Using a swivel hinge gradually increasing ﬂexion of the elbow joint starts at an average 2–6◦ per day in four to six stages. The ﬂexion rate must be reduced if pain occurs or if there are signs of irritation of the great vessels and nerves. The manipulations must not cause any pain. The evaluation as to whether the amount of movement of the swivel hinge causes no pain must be made in the morning. Only after a night without analgesia should an increase in the rate of joint movement be recommended.Systematic prescription of analgesics for development of movement “at any cost” is impermissible. After forearm ﬂexion to an angle of 130–140◦ has been achieved, its extension starts at the same rate. After the full cycle of “ﬂexion–extension” is completed, it is repeated. The repeat cycle usually takes less time. After 10–15 passive ﬂexion and extension cycles the time for a full cycle is reduced to several minutes. Passive movements are then supplemented by development of active movements, for which the arms of the swivel hinge are disconnected. Over 3–7 days a gradual transition is made to the priority development of active movements. Then the device is dismantled and restorative treatment continues. The procedure for using external fixation devices presented is intended for patients with stiffness with no bone component. If the joint surfaces are congruent installation of the device is preceded by arthroplasty

286

2 Specific Aspects of External Fixation

a

b IV,10-4; IV,8-2 —— VII,3-9 ←◦→ III,3-9 —— VI,4-10; VI,6-12(V,6-12) (a) 130 3/4 130 3/4 120 120 IV,8,90; V,10-4 —— VII,3-9 ←◦→ II,6,90; III,9-3; IV,6,90 130

3/4 130

3/4 120

(b)

Fig. 2.14.5a,b. Schemes for an Ilizarov device (a) and CEF device (b) for reduction of chronic dislocations of the forearm. Distraction starts on the 3rd to the 5th day at a rate of 0.25 mm six to eight times a day. The rate of distraction is decreased if pain or signs of hyperextension of the great vessels and nerves occur. After lateral radiographs confirm the presence of the necessary diastasis for unhindered horizontal movement of the ulnar epiphysis, the subsystem connecting the modules is remounted. Its construction (Fig. 1.6.4–1.6.8) depends on the type of dislocation: anterior, posterior, medial, lateral

2.14 Large Joint Pathology

287

Fig. 2.14.6. Axial hinges are installed according to the axis of movement of the elbow joint approximately 1.2 cm from the joint space [26, 105] at the level of a line connecting the epicondyles of the humerus. A diastasis of 2–3 mm is created between the joint surfaces. Introducing water in the joint under pressure (using the arthroscopic technique) is beneficial

Fig. 2.14.7. Restriction of extension of the elbow joint because of lack of conformity between the ulnar process and its fossa, decentralization, or hypertrophy of the top of the ulnar process can be corrected by modifying the curvature of the trochlear notch. For this purpose, in accordance with the results of specific calculations, a wedge of bone at the base of the ulnar process is removed [26]. Osteosynthesis of the ulnar process is then performed as for fractures (Fig. 2.3.3). The supports for tensioning the compression wires are used as the module of the device for subsequent development of movements in the elbow joint

V,10,120; VI,7-1 →← 0,4-10; I,10-4 —— V,6,90 130

2/3 130

120

Fig. 2.14.8. For compression arthrodesis of the elbow joint installation of the device is preceded by removal of the joint surfaces and their adaptation by placing the forearm in the position 80/80. A wire is then inserted through the ulnar process base in the ulna. The direction of the wire must precisely coincide with the vector of the compression force providing only mutual compression of the humerus and ulna without risk of sliding. Then for convenience of the device mounting one or two diafixing wires are additionally inserted. Note that the device supports are located perpendicular to the compression force vector rather than to the anatomical axes of the bone fragments. The support VI,6,90 is of auxiliary significance

288

2 Specific Aspects of External Fixation

which may include, according to the indications, partial removal of the ulnar processes, excavation of the olecranon fossa, removal of ossified material.

2.14.3

Wrist

In this section we consider the fundamentals of external fixation of chronic dislocations of the hand, stiffness of the wrist joint, and arthrodesis of the wrist joint (Figs. 2.14.9–2.14.11). In dislocations and fracture-dislocations of the wrist joint (wrist bones), provided there are indications for open reduction, the use of a distraction device must be considered as the first mandatory stage of surgical treatment [106]. If up to 2 weeks has passed since the trauma, the device is applied by means of an incision to ease reduction. The device is based on two wires with stops tensioned in two half-ring supports: VI,6-12(VI,6-12) ←→ m/carpV–m/carpII. This device is removed immediately after restoration of the anatomy of the wrist joint and diafixation by the wires. In nonacute injuries (3–4 weeks since the trauma) a single-step reduction of the dislocation is possible; however, if there is insufficient experience in the treatment of such patients the recommended first stage is to apply a distraction device based on two supports: VI,6-12(VI,6-12); VI,4-10←→ m/carpV–m/carpII.Distraction at a rate of 0.25 mm four to six times a day starts from the second day. Five to seven days are usually enough to “stretch” the joint, thus providing more convenient conditions for open intervention. In chronic injuries 8–9 months old with osteoporosis and marked rigidity of the soft tissues, the distraction device must include a large number of transosseous elements (Fig. 2.14.9). The distraction period usually lasts 7–12 days.After open reduction the device can be left in place not only for immobilization but also to remove the load from the injured structures to prevent aseptic necrosis. The Russian Ilizarov Research Center has developed methods for the use the Ilizarov “minidevice” for the treatment of fractures of the wrist bones and metacarpal bones that also involves the use of a large device to facilitate reduction. In 5–7 days the large device is removed and further fixation of the bone fragments involves only the minidevice [93]. One of the conditions for successful external fixation for elimination of stiffness in the wrist joint is to use the reference positions described in the atlas for insertion of transosseous elements. The device given in Fig. 2.14.10 is recommended. Flexion stiffness is the most frequently occurring wrist joint problem in clinical practice. With a swivel hinge gradually increasing extension starts at an average rate of 2–6◦ per day in four to six stages. Flexion

(V,3-9); VI,6-12(VI,6-12); VI,4-10 ←◦→ 120

m/carpII–m-carpIV; m/carpV–m/carpIII 2/3 120

Fig. 2.14.9. Distraction device for the wrist joint. A wire is inserted through metacarpal bones II and IV; a second wire is inserted through metacarpal bones V and III. After tensioning they are fixed to a two-thirds or three-quarter ring support. The transosseous module on the forearm is based on three wires fixed to one ring support

must be decreased if pain occurs or if there are signs of irritation of the vessels and nerves that can be manifested as finger blanching or paraesthesia. The manipulations must not cause any pain. The evaluation as to whether the amount of movement of the swivel hinge causes no pain must be made in the morning.Only after a night without analgesia should an increase in the rate of joint movement be recommended. Systematic prescription of analgesics for development of movement “at any cost” is impermissible. After dorsal ﬂexion of the hand to an angle of 40– 45◦ is achieved, the device is stabilized for 2–3 days. Return to the initial position of the palmar ﬂexion does not usually cause any difficulties. After 10–15 cycles of passive ﬂexion and extension the time for an full cycle is reduced to several minutes. Passive movements are then supplemented by development of active move-

2.14 Large Joint Pathology

2.14.4

V,6-12(V,6-12); V,4-10 —— VIII,6-12(VIII,6-12) 120

120

←◦→ m/carpII–m-carpIV; m/carpV–m/carpIII 2/3 120

Fig. 2.14.10. In the device for elimination of wrist joint stiffness the axial hinges are installed according to the axis of movement of the wrist joint, that is along the lower edge of the styloid process of the radius [105]. A diastasis of 2–3 mm is created between the joint surfaces. Introducing water in the joint under pressure (using the arthroscopic technique) is beneficial

ments, for which the arms of the swivel hinge are disconnected. Over 3–7 days a gradual transition is made to the priority development of active movements. Then the device is removed and restorative treatment is continued. For arthrodesis of the wrist joint the hand is placed in dorsal ﬂexion of 20◦ . The device is analogous to that shown in Fig. 2.14.10. If, after removal of the traumatic defect of the epiphysis of the radius, the excess length of the ulna does not exceed 2 cm, its distal epiphysis is resected and used as grafting material. If the defect of the distal end of the radius is greater than 2 cm, it must be replaced with bone graft or by lengthening the remaining part of the bone according to the method of Ilizarov. This subject is discussed in more detail in sections 2.10 and 2.11.

289

Hip

In this section we consider the fundamentals of external fixation of dislocations of the hip and arthrodesis of the hip joint (Figs. 2.14.12–2.14.16). Surgery is carried out with the patient on an orthopaedic traction table with a pelvic support and perineal rest. Both legs are abducted at 15–20◦ with moderate traction to the feet. Ilizarov external fixation of a central dislocation of the hip starts with insertion of two wires with stops through the wing of the ilium. (The main discussion of external fixation of acetabulum fractures is in section 2.12.) One wire is inserted through the anterosuperior spine and the other wire is inserted from the back to the front at an angle of 30◦ to the first wire. Both wires are tensioned and fixed to the basic arched support. Two crossing wires are inserted into the supracondylar area of the femur and fixed after tensioning to the ring support: VII,2-8; VII,4-10. The arch and ring are connected at the front and at the back by telescopic rods and by a bar along the external aspect. After that wire I,12-6 is inserted through the external part of the greater trochanter preliminarily displacing the soft tissues inwards. The wire is tensioned and fixed to the reductionally fixing arch support. The arch is connected by two threaded pulls to the bar (Fig. 2.14.12a). A distraction force is applied along the telescopic rods connecting the proximal and distal supports. Then, by tightening the nuts of the rods connecting the reductionally fixing support to the support bar, the proximal part of the hip is brought outwards. A radiographic examination is carried or the CRM is used. To optimize the effect of the ligamentotaxis the head of the femur must be placed in a position of light hypercorrection. When a hybrid device is used two half-pins and one wire are inserted into the ilium. The wire is inserted into the anterosuperior spine of the ilium at an angle of 30–35◦ to the sagittal plane and at 40–45◦ to the horizontal plane (the angle is distally open). The first half-pin is inserted into the anteroinferior spine of the ilium at an angle of 45◦ to the sagittal plane perpendicular to the vertical axis of the body 3–3.5 cm deep [85]. The second half-pin is inserted into the anterior third of the wing of the ilium in an outside inwards and downwards at an angle of 20–30◦ to the sagittal plane. The transosseous elements are fixed to a one-thirds ring support. If the roof of the acetabulum is intact, a third half-pin is inserted into it. If a wire is not used a one-third ring support is used as the basic support. Two wires are then inserted through the distal part of the femur and fixed after tensioning to the ring support: VII,9-3; VII,8-2. The two basic supports are con-

290

2 Specific Aspects of External Fixation

a

b

c

d

e

f Fig. 2.14.11a–f. Scheme for reconstruction of the forearm in defects of the ulna and radius, chronic osteomyelitis or extensive defects of the soft tissues (a). A non-free graft is transplanted from the radius to the ulna defect, and arthrodesis of the distal part of the ulna with the first row of wrist bones and combined osteosynthesis are performed (b). After arthrodesis is achieved in 9 weeks the distal support is removed (c–e). The device is removed 5 months after surgery (f)

2.14 Large Joint Pathology

Fig. 2.14.12. Scheme for an Ilizarov device for correction of a central dislocation of the hip. If adduction of the hip occurs during distraction an additional support is mounted on the wing of the ilium in a manner analogous to that shown in Fig. 2.12.22

nected by two telescopic rods and a distraction force is applied to moderately tension the soft tissues. Half-pin I,9,70 with a thread is inserted into the greater trochanter. If marked osteoporosis or nonacute dislocation is present an additional half-pin II,9,70 is inserted. A bar is installed in immediate proximity to the half-pin and the ends of the bar are fixed to the basic supports. The free end of the half-pin is connected to the bar so that traction on the pin applies a force not perpendicular to the anatomical axis of the femur but at an angle of 110–115◦ to it as shown in Fig. 2.14.13. Insertion of the half-pin at an angle of 70– 75◦ and the application of a traction force at an angle of 110–115◦ to the anatomical axis of the femur decreases the risk of forcing out the half-pin and is better biomechanically in bringing the proximal part of the femur outwards. After confirmation of elimination of the dislocation and reduction of the bone fragments the device is stabilized. The average immobilization period is 6 weeks. The external fixation devices for fractures of the roof of the acetabulum with superior dislocations of the hip generally coincide with those recommended for central dislocations of the hip. Distraction between the proximal and distal basic supports ensures abduction of the proximal femur to the level of the acetabulum and reduction of the dislocation. If the radiograph shows that the large splinter of the roof of the acetabulum has not been sufficiently abducted, the distraction between the supports is continued down to the inferior

291

Fig. 2.14.13. Scheme for mounting a hybrid device for correction of a central dislocation of the hip. Traction at half-pin I,9,70 is performed simultaneously with separation of the basic supports so that the femur transposition vector is parallel to the axis of the neck of the femur. If adduction of the femur occurs the device is stabilized by mounting of an additional support on the contralateral coxal bone

incomplete dislocation of the hip. In the reduced state the splinter is fixed by one or two console wires. In reduction fails, presence of small bone splinters in the cavity of the joint makes moving to open intervention necessary. The operation of compression arthrodesis of the hip joint starts with removal of the joint surfaces and adaptation of the stump of the neck of the femur to the acetabulum. The hip is placed abducted at 10◦ and ﬂexed at 30◦ for those in sedentary occupations and 20◦ for those whose occupation mostly involves standing and walking [102]. To increase the contact areas in the acetabulum a slot is made corresponding to the diameter of the femoral neck. If there is a defect in the proximal part of the femur or insufficient area of the surfaces being aligned, a slot is made in the greater trochanter and the roof of the acetabulum and a spongy transplant is placed in it from the acetabular area or the wing of the ilium. Before installation of the device (Fig. 2.14.14) two or three diafixing wires are inserted.

2.14.5

Knee

In this section we consider the fundamentals of external fixation of dislocations of the lower leg and knee joint arthrodesis (Figs. 2.14.17–2.14.22). For closed reduction of lower leg dislocations the first stage involves mounting a transosseous module based on wires (Fig. 2.14.17a) or a hybrid module (Fig. 2.14.17b) on the femur. A second module that can

292

2 Specific Aspects of External Fixation

Fig. 2.14.14. The device for compression arthrodesis of the hip joint generally corresponds to the device recommended for elimination of hip dislocations and includes three external supports. It is recommended, especially in the presence of osteoporosis, that two half-pins I,8,120; II,10,90 are inserted at the level of the intermediate supports. To avoid hinge connections the proximal basic support is installed parallel to the distal basic support mounted at level VI of the femur: V,8,120; VI,3-9. Compression is created on the operating table by approximation of the basic supports and through medial transposition of the intermediate support

a

b

Fig. 2.14.15a,b. To lengthen a shortened femur the segment can be lengthened at the same time as the arthrodesis. The support fixing the coxal bone is unchanged. The femur is fixed by device I,8,120; II,8,120 —— IV ←→ VI,8,120; VII,3-9. Insertion of half-pins at two proximal levels in the projection of position 8 (or 9) is necessary to create a compression force, its vector maximum coinciding with the anatomical axis of the femoral neck (a). After lengthening the femur by up to 1–2 cm to restore the length of the extremity, half-pin V,8,90 or V,9,90 is inserted. This helps to correct (if required) the position of the distal fragment and to stabilize the device fixing it to the reductionally fixing support. If ankylosis has taken place (usually in 2–3 months) and the femur requires further fixation, half-pin II,11,90 is inserted and fixed to the proximal support of the femur. The support is then removed from the pelvis (b)

2.14 Large Joint Pathology

Fig. 2.14.16. In females with a defect of the proximal part of the femur and ankylosis in an inappropriate position a reconstructive operation is performed to improve sexual function

also be based on wires or a hybrid module is mounted on the lower leg.A hinge-distraction system is installed between the modules. If the dislocation of the shin is a complication of femur lengthening, an additional transosseous module is mounted on the lower leg and connected by a hinge subsystem to the basic support. One of the conditions for successful external fixation for knee joint stiffness is to use the reference positions described in the atlas for insertion of transosseous elements (section 1.9). The assembly shown in Fig. 2.14.17b can be used.8 It is important to recognize that treatment of knee joint stiffness is quite a complicated problem and it is not always possible to solve it by external fixation only [107].One should have a clear idea of the functional and anatomical-topographic characteristics of the femur muscles and the degree of development of the cicatricial process in the knee joint and paraarticular tissues. Preoperative examination includes electromyography, ultrasonography, computed tomography, magnetic resonance imaging, and particularly contrast roentgenography of the muscles [108, 109]. The data from the clinical/functional examinations allow four groups of patients to be identified (Table 2.4). 8

There are devices that take more account of the biomechanics of the movements in the knee joint; for example the device of Volkov and Oganesyan [105, 142], and the modified device of Ilizarov [4].

293

Reconstruction of the knee joint involves various variants and modifications of operations to mobilize and reconstruct the quadriceps [29, 112–115]. Lengthening of the distal tendon of the quadriceps in adults is undesirable as it will result in restricted active extension of the lower leg. Besides, external fixation allows a gradual increase in ﬂexion of the lower leg to the necessary angle in the postoperative period. In neurogenic stiffness of the knee joint lengthening of the semitendinosus, semimembranosus biceps femoris by external fixation is comparatively rarely indicated – in case of a continuous process there is a tendency to spasticity. Apart from the indicators given in Table 2.4, it is necessary to take into account: 1. The degree and duration of the stiffness and the patient’s age. 2. The patient’s attitude to treatment and his/her desire to restore the amplitude of the knee joint movement. Some patients insist on the maximum possible restoration of joint movement, for others restoration of 30–45% of movement amplitude is sufficient for their social rehabilitation. 3. The intensity of changes to the articulating surface of the femur. For example, in extension stiffness, a 40% shortening of the belly of the rectus and median muscles due to their atrophy and fibrous changes prejudices the possibility of restoration of full active extension of the lower leg. 4. The presence and characteristics of a chronic inﬂammatory process of the femur or knee joint. 5. The presence of another orthopaedic pathology: nonunions or deformities, including shortening of the femur or lower leg. These factors form the basis for drawing up informed consent to be signed by the patient before the operation so that the patient is aware of the real chances of success and the limitations of restorative surgery. It is known that major stiffness of the knee joint may result in a state of decompensation, even with a normal axis and length of the lower extremities [116]. Therefore one should use all means to improve, if not to restore, the function of the knee joint. Signs of gonarthrosis are not a contraindication. If extension stiffness occurs during femur lengthening, especially during formation of a regenerate in the distal third of the segment and the closed redressment failed, external fixation can be used. For this purpose a transosseous module is mounted on the lower leg as shown in Fig. 2.14.17 or the module is based on two half-pins and a wire (Fig. 2.14.20b). The module is connected by a hinge subsystem to the basic support. This approach should be used if extension stiff-

294

2 Specific Aspects of External Fixation

a

b

7 —— VII,3-9; VII,8-2 ←◦→ II,3-9; II,10-4 —— VII,2-8; VII,4-10 (a) III,12-6; III,7-1 arc 210 180 3/4 150 150 II,8,90; III,10,90 —— VI,8,120; VII,3-9 ←◦→ II,3-9; II,10-4; IV,12,70 1/3 210

180

3/4 150

(b)

Fig. 2.14.17a,b. Schemes for an Ilizarov device (a) and a CEF device (b) for reduction of the lower leg. The external supports of the module fixed to the femur are located parallel to the axis of the femoral condyles. Distraction starts on the 3rd to the 5th day at a rate of 0.25 mm six to eight times a day. The distraction rate is decreased if pain or signs of hyperextension of the great vessels and nerves occur. In lateral (external, internal) dislocations and subluxations the distraction first must be uniform on all three hinges. After radiographic confirmation of the presence of the necessary diastasis for unhindered movement of the lower leg in the horizontal plane the subsystem connecting the modules is remounted (Figs. 1.6.4–1.6.8). The remounting depends on the type of dislocation: anterior, posterior, medial or lateral. After reduction of the dislocation the knee joint is fixed in the midphysiological position for 2–3 weeks. After that the device can be used to develop movements in the knee joint

Fig. 2.14.18. Axial hinges are installed between the transosseous modules fixing the femur and the lower leg 2 cm from the joint surface, and at the junction of the middle and posterior thirds of the femoral condyle [110, 111]

2.14 Large Joint Pathology

a

b

295

c

Fig. 2.14.19a–c. The swivel hinge is installed on the anterior and posterior surface or on both sides

VI,8,120; VII,3-9; VIII,4,90 (a)

a

b

I,1,90; II,3-9; III,12,120

(b)

Fig. 2.14.20a,b. Alternative supports for the femur and tibia

ness forms during treatment of femoral fractures, specially open injuries to the distal third of the segment. This approach ensures that the emergence of rough cicatricial unions of tendons and muscles with the bone in the place of the fracture is avoided.

The surgeon must be prepared for the following. In most cases all supports of the device fixing the femur are located perpendicular to the anatomical (middiaphyseal) axis of the femoral bone. Accordingly, the distal basic ring (as well as all supports) is not parallel

296

2 Specific Aspects of External Fixation

Table 2.4. Groups of patients with knee joint stiffness and its treatment Group

Reason for stiffness

Clinical/laboratory data

Treatment

I

Immobilization of fractures of the proximal and middle third of the femur; less frequently, fixing of the knee by bandaging in fractures of the lower leg

The stiffness is not associated with a cicatricial process in the knee joint; there are no rough unions or malunions between muscle and bone (myofasciodeses). Conservative treatment, including redressment attempts over 2–3 months, have failed

Passive-active development of movement using an external fixation device

The femur muscles are intact or have no marked secondary fibrous changes or atrophy. The points of pathological fixation of the muscles to the femur are not available or not marked. A cicatricial process occurs in the knee joint cavity and paraarticular tissues The stiffness is not associated with a cicatricial process in the knee joint or it is not marked and is secondary in character. Marked signs of myofasciodesis: cicatricial union of muscles and tendons with bone, union of tissues

Arthroscopic release of the knee joint with subsequent passiveactive development of movement using an external fixation device

Complication of lengthening of the femur (extension stiffness) or lower leg (flexion stiffness) II

Inflammatory process in the knee joint or intraarticular fracture

III

Fracture of the distal third of the femur

IV

United open fracture, after extensive injury of the soft tissues of the distal femoral muscle; osteomyelitis in remission

The stiffness is associated with a cicatricial process in the paraarticular tissues; polylocal myofasciodeses

to the knee joint plane.Therefore,to install axial hinges, an additional support fixed at the necessary angle to the distal basic support of the femur must be introduced into the assembly.Another possibility is to use complex hinges, one part serving for fixation to the distal basic support of the femur device and the other the axial hinge itself. The formation of persistent ﬂexion stiffness of the knee joint that does not respond to conservative treatment can be a complication of lengthening of the lower leg. Lack of loading on the extremity can negatively affect the distraction regenerate; thus, the stiffness needs to be eliminated as soon as possible. For this purpose a transosseous module is mounted on the femur as shown in Fig. 2.14.17 or a ring support based on a wire and two half-pins is used (Fig. 2.14.20a). If patellofemoral synostosis or fibrous union of the patella with the femoral bone has occurred its open or arthroscopic mobilization is required. After this a wire is inserted through the patella in the frontal plane and

“Semiclosed” with a local process or open myolysis with reconstruction of the articulating surface. If required, release of the knee joint. Subsequent development of movement in the knee joint using an external fixation device Open arthrolysis, myolysis with reconstruction of the articulating surface with subsequent passive-active development of movement using an external fixation device

tensioned in the additional half-ring support. The support is fixed to the basic support thus creating diastasis between the patella and the femur. Frequently in clinical practice extension stiffness of the knee joint is present together with a nonunion, deformity, defect or shortening of the femur. Simultaneous restoration of the anatomy and function of the injured extremity is the priority in planning the rehabilitation of the patient.At the same time, the operation for single-stage restoration of the knee joint function must be performed with the participation of a surgeon with experience of such interventions. The opinion that following external fixation of the femur (particularly lengthening) there necessarily emerges marked restriction of knee joint movement currently needs revision. This problem can be avoided by the use of a CEF device and the observance of the recommendations for postoperative management of the patient.

2.14 Large Joint Pathology

A single-stage operation to treat a traumatic injury simultaneously with mobilization of the knee joint involves the following: 1. In malunited fractures with angular and rotational deformity exceeding 15–20◦,a shortening osteotomy of 20–40 mm is recommended with subsequent gradual correction of the deformity. 2. In hypertrophic defect pseudoarthroses and anatomical shortening of the femur by 2–3 cm microdistraction is performed to eliminate the inequality in the lengths of the extremities and to restore the anatomy of the bone simultaneously with restoration of the knee joint movement. 3. If external fixation of a nonunion of the femur involves an intervention with an open stage (removal of a metal structure, osteoplasty), it is combined with an operation to mobilize the knee joint. 4. In atrophic nonunions of the femur and shortening of the segment by 40 mm the bone fragments are openly reduced using, according to the indications, osteoplasty, and corticotomy is performed with osteoclasia of the femoral bone to eliminate inequality in the lengths of the extremities [117]. 5. The operation to treat shortening of a lower extremity that is accompanied by severe stiffness of the knee joint after malunion of intraarticular fractures not more than 1.5 years after trauma starts with surgery to the knee joint. The congruity of the joint surfaces is restored and the joint is mobilized. The second stage involves lengthening of the segment [116]. It is known that the closer osteotomy is performed to the knee joint, the higher the danger of stiffness. Therefore, if the top of the deformity is located in the distal part of the femur or proximal part of the lower leg, correcting osteotomy is performed as far as possible from the knee joint. The issue is considered in more detail in section 2.8. Passive development of knee joint movement may have effects that result in destabilization of fragments in their zone of contact. If axial compression is at the junction of fragments it is easier to achieve rigidity of external fixation. Therefore, in correcting osteotomy for adaptation of fragments the bone wound should be located in a plane close to the transverse plane. An alternative to lengthening a shortened femur is to lengthen the lower leg providing unevenness of the knees is not rejected by the patient for aesthetic reasons. If the femur is shortened by more than 5–7 cm some of the shortening can be addressed by lengthening the femur and the rest by lengthening the lower leg. This allows an improvement in knee joint function, reduces the rehabilitation period, and reduces the unevenness of the knees.

297

In replacement of a segmental defect of the femur by the Ilizarov method operative approaches to improve the function of the knee joint must be postponed at least until adaptation of the transposed fragment to the basic fragment and their stabilization. Arthrolysis and myolysis can be performed in a single step with open adaptation of the transposed and basic bone fragments. Multiple solid myofasciodeses, filling the knee joint cavity with healing tissue, osteomyelitis favours a two-stage treatment for restoration of the weightbearing ability of the extremity and then improve knee joint function. After closed operations the knee joint is stabilized in the position achieved by maximum elimination of the stiffness. However, to reduce pain we have to reduce the position in the joint achieved by the end of the operation by 30–50%. It often happens that after open arthrolysis and myolysis, to avoid excessive skin stretching the skin is taken in with the knee joint ﬂexed less than was achieved during the operation. To reduce the risk of soft-tissue necrosis after surgery the knee joint is stabilized in a position that ensures good blood supply to the wound edges. If there is a marked cicatricial process occurring in the area of the knee joint, the knee is stabilized in a position close to full extension. A diastasis of 5–6 mm is created between the joint surfaces in two or three stages. It is important to note that due to the ﬂexure of the transosseous elements the amount of separation on hinges will not correspond to the joint space. Therefore, the effectiveness of the distraction should be monitored radiographically. Radiographic monitoring of the installation of the axial hinges is also necessary. On the second or third day after closed osteosynthesis and after arthroscopic release, gradually increasing ﬂexion (extension in the presence of extension stiffness) of the lower leg starts by means of a swivel hinge at an average rate of 2–6◦ per day in four to six stages. The rate is reduced if pain occurs or if there are signs of irritation of the great vessels and nerves. The manipulations must not cause any pain. The evaluation as to whether the amount of movement of the swivel hinge causes no pain must be made in the morning. Only after a night without analgesia should an increase in the rate of joint movement be recommended. Systematic prescription of analgesics for development of movement “at any cost” is impermissible.After the skin has healed following open arthrolysis and myolysis redressment of the knee joint under raush-anaesthesia is recommended. After ﬂexion of the lower leg to an angle of 120◦ has been achieved (or less if planned preoperatively), extension starts at the same rate. The same is done for ﬂexion stiffness. When the full cycle of ﬂexion-

298

2 Specific Aspects of External Fixation

Fig. 2.14.21a,b. Devices for compression arthrodesis of the knee joint. It should be noted that in arthrodesis there is no need to use reference positions for the transosseous elements. The choice can be expanded through the use of safe positions. For lengthening the extremity by 3–4 cm the method of lengthening arthrodesis is used which involves gradual separation of the modules on the femur and lower leg at a rate of 0.25 mm three or four times a day starting after 2–3 weeks

a

b 3

4

1

2

5

6

7

8

V,8-2; V,1-7 —— VII,2-8; VII,4-10 →← I,2-8; I,4-10 —— III,9-3; III,4-10 (a) 180 180 160 160 2

1

3

4

5

6

VI,2,120; VII,4-10; VIII,8,90 →← I,2-8; I,10-4; III,12,120 180

(b)

160

extension is completed, it is repeated. The repeat cycle usually takes less time. After 10–15 cycles of passive ﬂexion and extension the time for a full cycle is reduced to several minutes. Passive movements are then supplemented by the development of active movements. For this the arms of the swivel hinge are disconnected. Over 3–7 days a gradual transition is made to the priority development of active movements. The device for development of movements can be removed after the patient can achieve ﬂexion–extension of the knee joint in 10–20 minutes [115]. Restorative treatment involving massage, exercise therapy and myostimulation is continued. Arthrodesis of the knee joint starts with removal of the joint surfaces and adaptation of the prepared bone ends with the lower leg in 10◦ of ﬂexion and 10◦ of outward rotation. The fragments are stabilized with two or three wires. If the placement of the extremity is correct a long thread passing from the anteriorupper spine of the ilium to the first interdigit space passes across the middle of the patella [1]. Unless lengthening arthrodesis is planned, a rectangular autograft is formed from the patella. A slot is formed through both bones 2–3 mm smaller than the auto-

graft, which ensures a tight fit. The wound is cleaned and stitched. The external fixation device is then mounted. In Ilizarov external fixation crossing wires are inserted into the epicondylar area. Another pair of wires are inserted 8–10 cm more proximally. The wires are tensioned and fixed to two ring supports connected by three rods. A similar module is mounted on the lower leg. The modules are connected with bars and compression is applied at the junction of the bones (Fig. 2.14.21a). Figure 2.14.21b shows a hybrid variant of the device for compression arthrodesis of the knee joint.

2.14.6

Ankle

The fundamentals of external fixation of malleolus fractures are considered in section 2.5.4. In this section we consider external fixation for stiffness and arthrodesis of the ankle joint (Figs. 2.14.23–2.14.25). The device is assembled from two transosseous modules fixing the ankle and foot. The modules are connected by a hinge subsystem (for stiffness) or rods (for arthrodesis).

2.14 Large Joint Pathology

299

Fig. 2.14.22a,b. If the extremity is to be lengthened by more than 4 cm, the method of bilocal osteosynthesis is used. For that purpose the device is mounted so as to allow compression at the junction of the fragments after removal of the knee joint and distraction at the level of corticotomy with osteoclasis of the tibia (a). The newly inserted transosseous elements are further fixed to the intermediate support; the distal support can be removed 2– 3 weeks prior to the end of the fixation period (b). It is possible to obtain distraction regenerate at both at the level of contact of the femur and tibia and at the level of the lower leg

a

b 2

1

3

4

5

2

1

3

4

5

6

7

V,2,120; VII,4-10; VIII,8,90 →← I,9-3; II,12,90 ←→ IV —— VII,8-2; VII,4-10 (a) 180 160 160 160 6

7

8

V,2,120; VII,4-10; VIII,8,90 →← I,9-3; II,12,90 —— V,3-9; V,4-10; VII,11,70 180

160

Flexion stiffness of the ankle resulting in talipes equinus is frequent in clinical practice. The most frequent reasons for persistent ﬂexion stiffness are the consequence of breaking the rules concerning plaster immobilization and lower leg lengthening. These complications are grounds for using external fixation by “closed” methods. In stiffness resulting from the diseases that caused persistent relative shortening and changes of the gastrocnemius muscle (for example, due to previous poliomyelitis) or marked osteoporosis, the external fixation operation is performed simultaneously with lengthening of the Achilles tendon. In stiffness emerging after intraarticular fractures of the ankle joint, after a previous infectious process (provided there are no contraindications), arthroscopic release is performed in one stage at the same time as installation of the external fixation device. The intervention starts with mounting the transosseous module on the lower leg. If the lengthening of the lower leg is complicated by the presence of tal-

160

(b)

ipes equinus,the basic device is used.In other cases two pairs of wires are inserted and are fixed after tensioning to two ring supports. The supports are connected by three rods: VI,2-8; VI,4-10 —— (VIII,8-2)VIII,8-2; VIII,4-10. The lower leg module can be a combined single-support module: VII,1,120; (VIII,8-2)VIII,8-2; VIII,4-10. A module based on a lengthened closed halfring is mounted on the foot (Figs. 2.5.13 and 2.14.23). By means of swivel hinges gradual extension (ﬂexion in the case of ﬂexion stiffness) of the foot is started at an average of 2–6◦ per day in four to six stages on the second or third day. The rate is reduced if pain occurs or if there are signs of irritation of the great vessels and nerves. The manipulations must not cause any pain. Systematic prescription of analgesics for development of movements “at any cost” is impermissible. After extension to an angle of 15–20◦ has been achieved, the foot is stabilized for 3–5 days. After that ﬂexion is started, its rate being limited only by the occurrence of pain or a neutrophic disorder. After a full

300

2 Specific Aspects of External Fixation

Fig. 2.14.23. A hinge subsystem is installed between the transosseous modules fixing the lower leg and foot. The centre of rotation of the axial hinges on the external and internal surfaces of the foot must be located at the level of the centre of the head of the talus [4]9 . One swivel hinge is installed on the posterior aspect of the foot and one on the anterior aspect. A diastasis of 3–4 mm is created between the joint surfaces. It is important to note that due to flexure of the transosseous elements the value of the distraction force on the hinges will not correspond to the value of the distraction force at the joint space. Therefore, the effectiveness of the distraction should be monitored radiographically. Radiography is also necessary to make sure that the axial hinges have been properly installed

cycle of ﬂexion–extension is completed, it is repeated. The repeat cycle usually takes less time. After 10–15 passive ﬂexion and extension cycles the time for a full cycle is reduced to several minutes. Passive movements can be developed using a special automatic pneumatic attachment [15]. Passive movements are then supplemented by the development of active movements. For this purpose the arms of the swivel hinges are disconnected. Over 3–7 days a gradual transition is made to the priority development of active movements. The device for development of movements can be removed after the patient has achieved confident movements in the ankle joint. Restorative treatment involving massage, exercise therapy and myostimulation is continued. 9

According to Oganesyan et al. [15] the imaginary biomechanical axis of the ankle joint (rotational axis) passes under the medial malleolus, through the centre of the trochlea of the talus and comes out under the top of the lateral malleolus. In accordance with this the axial hinges should be installed.

Fig. 2.14.24. In case of simultaneous arthrodesis of the ankle and calcaneostragaloid joints two crossing wires are inserted through the heel bone, tarsal bones and metatarsal bones: calc.5–m/tars.V; calc.7–m/tars.I

External fixation is used when dorsal ﬂexion of the foot by 25–30◦ was not achieved after lengthening of the Achilles tendon. The foot is fixed by the device for 1–2 weeks, after which the hinge subsystem is used in accordance with the above descriptions. Compression arthrodesis of the ankle joint starts with removal of the joint surfaces.Any known approach can be used. At the same time, in external fixation the external approach has certain advantages: the resected lateral malleolus covers the bone saw lines of the tibia and fibula thus improving conditions for ankylosing the joint. A curved incision of 6–8 mm bypassing the lateral malleolus is made. Oblique osteotomy of the fibula is performed 1–2 cm above the ankle joint space. The talus–fibula ligaments are crossed and the distal fragment of the fibula together with the soft-tissue ﬂaps are adducted outwards and forward thus exposing the ankle joint space. The foot is maximally supinated, which facilitates removal of the articular cartilage from the talus and tibia.If the approach to the internal part of the joint is restricted there is a risk that a valgus position of the foot may result due to nonuniform removal; in such cases an additional medial approach is used. The medial malleolus is resected from a curved incision of 2–3 cm and the articular cartilage in the internal part of the joint is removed. The foot is moved backwards by 1–2 cm and placed in a functionally advantageous

2.15 Infectious Complications of Long-Bone Fractures

Fig. 2.14.25. Scheme for compression panarthrodesis of the foot with simultaneous mounting of a device for lengthening of the lower leg. Corticotomy with osteoclasis of the proximal metadiaphysis of the tibia is performed as the final stage of the operation. After completion of the distraction period a reduction-fixation wire IV,3-9 is inserted at the level of the intermediate support

olus. The wound is actively drained and sutured after haemostasis has been ensured. After that the external fixation device is mounted. Three wires are inserted through the lower leg and tensioned in the ring support: VI,3-9; (VII,8-2)VII,8-2; VII,4-10. To avoid injury of the anterior tibial vessels, anterior wire VI,3-9 is inserted close to the ridge of the tibia. If the lower leg is to be lengthened (see below), instead of wire (VII,8-2)VII,8-2, a wire is inserted only through the tibia immediately in front of the fibula: VII,8-2. It is possible to use a hybrid wire/pin support: VI,12,120; VII,3-9; (VII,8-2)VII,8-2. The wires through the foot bones are inserted in a plane parallel to the plane of installation of the basic support of the lower leg. In arthrodesis of the ankle joint the wires are inserted only through the talus. To stabilize the anterior part of the foot, a wire is inserted through metatarsals I–V. Three wires are tensioned and fixed in the lengthened closed support: talus,1-7; talus,11-5; m/tars.V–m/tars.I. In panarthrodesis of the foot (Fig. 2.14.25) two wires are inserted through the heel bone, one through the tarsal bones and one through the distal third of metatarsals I–V.If no correction of the shape of the foot is necessary (see section 2.13.4), all four wires are fixed in the lengthened closed support. The wires inserted through the heel bone are fixed directly to the support. The wires inserted through the middle part of the foot are arched backwards and fixed by distraction clamps to ensure compression osteosynthesis. Finally the wire with the stop inserted through the lateral malleolus and talus is tensioned by means of a distraction clamp fixed to the distal basic support. If segment is also shortened, the following Ilizarov device for lengthening the lower leg is mounted prior to the arthrodesis operation: 1

◦

◦

position: 80–105 in males and 95–110 in females. The surfaces in contact may need additional adaptation depending on the consequences of the foot displacement. This approach is also suitable for arthrodesis of the subtalar joint. For arthrodesis of the taloscaphoid and calcaneocuboid joints the incision is extended to the anterior aspect of the foot. After removal of the joint surfaces the fragments of the bones remaining after removal of the medial malleolus are used as grafting material. The foot is stabilized by two or three diafixing wires inserted from the heel side into the tibia. The osteotomied lateral malleolus is shortened by the amount of joint surface removed. Its internal cortical plate is then removed. This bone–soft-tissue ﬂap is used to cover the junction of the talar and tibial bones. A wire with a spiral stop is inserted in the frontal plane that must be located in the centre of the lateral malle-

301

2

5

I,8-2; I,4-10; II,1,90 —— IV —— 3/4 160 3

160

4

(VII,8-2)VII,8-2; VII,4-10 160

2.15 Infectious Complications of Long-Bone Fractures If infectious complications occur external fixation gives the best outcome and is the only method that should be implemented,because internal fixation is inadmissible and conservative methods cannot be the main ones. Only external fixation is able to provide the optimum conditions for treatment of infected bone and softtissue injuries and restoration of the anatomy and function of the extremities. The “purifying” effect of exter-

302

2 Specific Aspects of External Fixation

nal fixation on purulent defects of bones and joints is known. Thus, Ilizarov’s statement that“in the fire of the distraction regenerate burns the infection” has practical embodiment. The variety of pathologies that can be considered (aetiology, types, localization, process stages, etc.) are beyond the scope of a book of this size. Thus, we can discuss the general recommendations for the use of external fixation in infectious complications on the basis of the Russian Ilizarov Research Center techniques [118, 119]. The duration of fixation of fractures in the presence of infectious complications is quite often long. Therefore, the preoperative preparation, transosseous element insertion, assembly of the frame and the postoperative management should be given due attention. Transosseous elements should not be inserted if the bone or soft tissue is inﬂamed. This rule does not exclude wire insertion for bone transport for replacement of bone loss by Ilizarov’s method and transosseous element insertion in the presence of anaerobic gas infection. Infectious complications may result in changes to the topography of the main vessels and nerves due to deformation, extensive scarring and repeated operations. To reduce the risk of vessel and nerve damage during transosseous element insertion, additional preoperative imaging, including computed tomography, magnetic resonance imaging, and selective vasography, should be carried out. In the presence of infected tissue or extensive scarring, which are undesirable conditions for the insertion of transosseous elements, the use of only reference positions is not always possible. At the same time a particular patient may have an increased risk of joint stiffness or may already be experiencing restriction of mobility in adjacent joints. Thus, the necessity to use safe positions conﬂicts with the requirement to fulfil all the conditions for restoration of joint movement. External fixation allows priorities in this regard to be defined. The maintenance of the correct reduction of bone fragments and their rigid fixation are priorities in external fixation. Later, if the local dynamics are positive, transosseous elements should be replaced using reference positions. As a rule, a chronic infectious process accompanies osteoporosis which creates additional complexities for the achievement of fixation, mainly the maintenance of optimum rigidity of the fixed bone fragments. The decision-making process concerning these problems is discussed in section 2.16. The bone canal is drained only after insertion of transosseous elements, unless precautions are taken, the exception being fixing drainage tube by wires. Halfpins with a channel and a lateral aperture can be used

for bone canal drainage and the introduction of drugs [120]. Adjacent joint immobilization is often necessary in the presence of infectious complications of bone fractures. It is necessary to achieve some stabilization of joints in their physiological position. The forearm should be fixed in a position between supination and pronation. If for any reason the physiological position cannot be achieved, external fixation modules fixing bone fragments are connected by two axial hinges and a swivel hinge. After the physiological position of a joint has been achieved, the frame can be used for passive/active development of joint movement. Detailed information can be found in section 2.14. The decision to use of external fixation in the presence of infection is subordinate to the decisions concerning the problems of bone fragment reduction, the rigid fixing of the fragments and adequate wound drainage. The basic principles for deciding the approach to the specified tasks are outlined in the sections on external fixation of open fractures (section 2.6) and malunited fractures (section 2.7). During debridement only small bone fragments with no blood supply are removed. External fixation combined with modern antibacterial therapy and physiotherapy avoids the necessity to remove large bone defects. At the same time, high-energy trauma (for example, gun shot fractures) demands more radical surgery [121]. With acute purulent inﬂammation and extensive soft-tissue infection, it is impossible to place transosseous elements near a bone wound. In such cases, the stability of the basic supports should be increased. To achieve this, additional wires and half-pins are inserted at some distance from the basic support and are fixed by means of posts. After the soft-tissue inﬂammation has resolved, and taking into account the additional issues to be resolved, additional supports and transosseous elements can be placed near the fracture area. External fixation as treatment for chronic traumatic osteomyelitis during remission follows the principles outlined in sections 2.8 and 2.10. Nonviable bone can be radically removed at nonunions and pseudoarthroses. The stage of an infectious process in bone and the borders of the nonviable soft tissue can be defined by radiography, including enhanced images, fistulography, osteophlebography, computed tomography, and magnetic resonance imaging. The apparatus is assembled such as to allow subsequent replacement of a bone defect. After surgical wound processing, drainage and suturing of soft tissues have been performed, the operational field is again cleansed, and surgical drapes, gowns and gloves are changed. After that corticotomy of one or both

2.16 External Fixation in Children, the Elderly and the Senile

bone fragments (for bone transport) is done. When contraindications, such as gross haemodynamic instability of the patient or adverse local conditions, are present,bone transport is carried out during the second stage. With extensive tibia defects, “tibialization” (fibula transport) can be used which involves moving a fibula fragment toward the tibial defect. A more detailed discussion of the possible techniques is presented in section 2.10. With a hyperplastic type of osteogenesis and a chronic infectious process, external fixation can be used as the first stage to remove deformation and in the union of pseudoarthroses. The second stage is disinfection at the focus of the osteomyelitis. Either the damaged bone is replaced with a bone and muscle ﬂap [122] or the osteomyelitis focus is replaced with a graft of transported bone [123]. In the presence of an osteomyelitis cavity, the tactics for external fixation mainly depend on the size and location of the cavity [124]. If the cavity is located centrally and its the size does not exceed onethird of the diameter of the bone, oblique osteotomy through the cavity is carried out. The osteotomy begins 15–20 mm proximally and ends 15–20 mm distally. Sequestrations, pathological granulations and purulent contents are then removed. The wound is drained and sutured with one or two rows of sutures. Distraction at a rate of 0.25 mm four times a day is begun in 8 to 10 days. This procedure results in filling of the osteomyelitis cavity with new bone callus, removal of deformation and restoration of the length of the segment up to 50–70 mm. With a localized osteomyelitis cavity with the defect occupying one-third of the diameter of the bone, the cavity can be filled by bone transport, which can be formed above or below the defect. It is necessary to perform a sequestrectomy with removal of the cavity wall to the limits of the healthy tissue. In the presence of an extensive osteomyelitis cavity occupying one-half or more of the bone diameter, the bone should be resected to the limits of the healthy tissue. The defect is replaced by bone transport of one or both bone fragments (Fig. 2.10.5). The epimetaphysis is resected to the limits of the healthy tissue if the articulating ends of a bone are involved in a chronic inﬂammatory process.If the cortical plate with an articulating cartilage can be preserved, the role of external fixation is to remove the loading of the joint and to provide passive and active development of joint movement. If the articulating end of a bone is removed,compression arthrodesis is carried out.When the defect is at the distal articulating end of the radius, the excess length of the ulna does not exceed 2 cm, its distal articulating end is resected and used as an osteo-

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plasty filler material. If the defect at the distal end of the radius exceeds 2 cm, it should be replaced by a bone autograph or by lengthening the remaining part of the bone. In pathology of humeral and cubital joints, formation of neoarthrosis is an alternative method. The timing of subsequent arthroplasty is determined on an individual basis. When a soft-tissue defect occurs after fistulas and scars have been removed, the following method can be used. The location of the external support and the connecting rods that provide the proper positioning of the bone fragments are marked. The fragments are then positioned so as to allow wound closure without tension in the soft tissue. The deformities could be either angular or rotational or the fragments could be displaced laterally or longitudinally. It is necessary to remember the potential for the development of trophic disorders due to goffering or excessive ﬂexion of the main vessels and nerves. Bone fragments are stabilized in a the newly achieved position. After the soft-tissue wound has healed and removal of the sutures gradual restoration of the position of the bone fragments can be started.

2.16 External Fixation in Children, the Elderly and the Senile It is obviously impossible to precisely define age limits for the use of external fixation. External fixation is not recommended in children under 2 to 3 years of age. There are no data in the literature on the use of external fixation in children under 6 months of age. In planning operations, it is necessary to remember that any condition which prevents the patient from understanding or carrying out the doctor’s recommendations is a contraindication to external fixation. Therefore, if the patient is a young child or elderly it is necessary to ensure that the carers can help the patient carry out all instructions for the postoperative period, prevent nonauthorized adjustment of the device, and ensure observance of measures to prevent pin-tract infection. With these age groups, the method of frame construction (see section 1.11) has some special features. Insertion of wires and half-pins through bone growth zones is forbidden. In older patients insertion of transosseous elements near joints should be avoided because of osteoporosis. Half-pins should not be used in the presence of severe osteoporosis. There are a number of methods for increasing and maintaining a necessary level of rigidity of the external fixation (Fig. 2.16.1):

304

2 Specific Aspects of External Fixation

• Pairs of wires with a stop are inserted towards one another, for example: II,8-2; II,10-4. In severe osteoporosis, allograft bone discs can be used as stops. • Additional wires and half-pins inserted outside support plane are fixing with posts, for example: I, 11-5; I, 1-7; II, 6-12 or I, 11-5; I, 1-7; II, 9,70. • Wires are inserted at an angle to the anatomical axis of the bone, passing from one level to another. The support should be placed perpendicular to the bone anatomical axis and the ends of wires at some distance from it are fixed by means of posts, for example: I,6-II,12; II,11-I,5. • Drills of a smaller diameter are used for formation of half-pin holes. In an osteoporotic area, metaphyseal threaded cortical or cancellous half-pins are inserted into the shaft part of the bone at a sharp angle to the bone anatomical axis. • Strain is created in each module fixing bone fragments. Between two supports that fix a bone fragment, a moderate, slow compression force is applied in the module fixing one bone fragment, and a distraction force in the module fixing the second fragment. • The opposite ends of a wire are fixed at different sides [25]. • A “bicycle-wheel” effect is created [125]. These approaches to increasing the rigidity of osteosynthesis can be combined. In young children frame “minimization” is desirable. For this purpose, lighter materials. i.e., alloys of aluminium or titanium, or special grades of plastic are used. The use of multicoloured external supports in an assembly can have a positive psychological effect. To reduce the risk of injury, console wires are used instead of half-pins. Bulkiness and weight can be reduced by assembling the frame on two basic supports only. In such cases, the transosseous elements are not fixed to a reductionally fixing support, but by means of posts to the basic supports. This method can be used in senile patients as well [4, 126, 127]. However, it should also be born in mind that decreasing the number of external supports and transosseous elements reduces the reduction potential of the device as well as osteosynthesis rigidity. The specified methods of external fixation are recommended where the device is applied only to fix bone fragments or for insignificant correction of their spatial orientation. An easier result could be achieved using a complete assembly, and then using “modular transformation” to minimize the frame. This approach is inappropriate where, because of the shortness of a segment, the distance between the base support and the reduction wires is less than the length of a four-hole post.

Instability of the external fixation device is one of the principal reasons for some complications occurring. A large external support should be used in obese patients, it reduces osteosynthesis rigidity. In such patients, it is not advisable to apply the minimized frame assembly with a reduced quantity of external supports. Indeed, it is necessary to insert additional transosseous elements, use hybrid and pin-based configurations and connect the external support with four or five threaded rods. Diabetes is not a contraindication to external fixation. Only decompensated and serious forms of the disease have preliminary specific therapy [107]. Pin-based and hybrid devices provide the better stability of bone fragment fixation than wire-based devices. It is especially important in the elderly and weak patients when gradual weight-bearing cannot always be guaranteed. In external fixation of the femur, these types of devices are more convenient for patients as they allow comfortable sitting and do not require special beds. Children, in contrast to the elderly, have less sensitivity to pain.Therefore,it is necessary to pay due attention to measures to prevent pin-induced joint stiffness. The use of the reference positions for insertion of transosseous elements plays an important role among other preventive procedures. The decrease in elasticity of the soft tissues in the elderly and obesity are the main reasons for insertion of transosseous elements in positions with minimal displacement of soft tissues, and also at places with less soft-tissue thickness. This issue is immensely important for external fixation of the humerus and femur. Wires and half-pins should not be inserted in positions 5, 6 or 7 at any level in patients with ﬂabby skin or muscles. When the operation has been completed, it is necessary to be sure of the absence of wire and half-pin pressure over the soft tissues with change in the position of the extremity. To check this for external fixation of the humerus, the patient is seated on an operation table. For fixation of the lower leg, the lower leg should be held vertical by knee joint ﬂexion. If necessary an incision is made in the skin and fascia with a scalpel and the transosseous elements displaced through the formed channel and the skin sutured. If a soft-tissue channel of more than 30 mm is needed, it is better that the transosseous element be replaced, if possible. Similar complications may occur with wires inserted at the first three levels of the humerus or femur. It is necessary to determine the amount of pressure on the soft tissue from the transosseous elements, which is only possible in the postoperative period when the patient starts using the extremity. Therefore ma-

2.17 General Principles of Patient Management in the Postoperative Period

305

b

a

c

I,8-2; I,4-10; II,3-9 ←→ III,12,120; IV,3-9 →← V,8-2; VI,4-10 ←→ VIII,2-VII,8; VIII,10-VII,4

(a)

Fig. 2.16.1a–c. General diagrams of methods for increasing the rigidity of osteosynthesis

nipulations to release the soft tissues are carried out late on the second or third day in a dressing room. It is important in patients of this age group to achieve accurate bone fragment reduction in fractures. Furthermore, reduced potential for regenerate formation in the elderly makes maintenance of all conditions (accurate reduction included) for successful bone wound healing essential. Bone fragment union in the wrong position in children can have gross effects on extremity function. Furthermore, in the elderly, in humerus and forearm bone malunion complete restoration of a segment length is unlikely. Shortening of the humerus and even shortening of the forearm bones up to 50 mm can affect arm function.

At the end of the operation, it is necessary to carefully bend the free ends of the wires so that they closely approach a support of the device, and to put on caps.

2.17 General Principles of Patient Management in the Postoperative Period After surgery it is necessary to check the peripheral pulse the colour of the skin.After recovery from anaesthesia, nerve function tests are carried out.

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2.17.1

2 Specific Aspects of External Fixation

Position in Bed

The bed for patients who have undergone external fixation should be equipped with a Balkan frame for subsequent exercise therapy (Fig. 2.17.1). After external fixation of the humerus, a wedge-shaped pillow is placed between the side of the body and the device so that the arm is abducted by 35–45◦ . After external fixation of the forearm, the arm is elevated by placing it on a roll or pillow. Two rods are fixed to the distal support of the forearm between which a gauze sling is attached to support the hand in the midphysiological position. After external fixation of the femur the patient should stay in bed for 7–10 days with the knee ﬂexed at 90–100◦. A convenient method is to attach the distal support with an elastic fixator to the Balkan frame. It is also possible to use a stand made from the components of the Ilizarov apparatus, one end of which is fixed to the distal support and the other rests against the bed. The first night after the operation is particularly important. After the patient has regained consciousness the knee joint is ﬂexed. The time spent in bed with the knee joint ﬂexed can gradually be reduced. After external fixation of the bones of the lower leg the extremity is kept elevated for 2–4 days. A footsupport, which limits plantar ﬂexion (Fig. 1.10.1), is used. In fractures it is used until the active range of motion in the ankle joint is not less than 30/0/5. When correcting deformities, and especially lengthening of the lower leg, the foot-support should not be removed for the entire period of distraction, and should preferably be kept on overnight for the entire period of fixation.

2.17.2

Anaesthesia

Narcotic and non-narcotic analgesics are used for the first 2 or 3 days after the operation. The need for further administration of drugs is determined individually.After external fixation for acute trauma, pain in the fracture region should last no more than 3 or 4 days. Remaining stable pain indicates, generally, a technical problem with the external fixation. First, it is necessary to remove pressure from the transosseous elements on the soft tissue by releasing the skin and fascia, if necessary, and by moving the element in the tunnel formed in the soft tissue. The skin is then sutured. There is more information about treatment and prophylaxis of pain in the section 2.18. Pain is a symptoms of most the complications discussed.A reduction in pain threshold and psychological lability of the patient suggest that a consultation with a psychotherapist may be beneficial.

Fig. 2.17.1. A special trolley and bed (with a recess for the frame) are required after Ilizarov external fixation of the femur [92]

2.17.3

Dressings

The first dressings are generally applied the day after the operation. All gauze dressings are removed. The skin and device components are carefully cleaned of blood and wound exudate using a solution of hydrogen peroxide. The exit sites of the transosseous elements are treated with iodine solution, the traces of which are removed using alcohol solution to prevent skin burn. The next step is to cover the exit sites of the transosseous elements with gauze dressings impregnated with 70% ethyl alcohol solution. The dressing should not be wound on the wire because this leads to pressure on the skin. The dressing is cut to the middle, put over the wire and pressed to the skin with a holder. For the first 2 or 3 days the dressings are changed every day, or as necessary, and thereafter as they become dirty, but at least once every 7–10 days. The cotton cover is changed together with the dressings. During each dressing change the skin tension at the transosseous elements is estimated and changes in oedema determined by measuring the circumference of the extremity at the level of the bone wound, and above and below it.

2.17 General Principles of Patient Management in the Postoperative Period

2.17.4

Exercise Therapy

The protocol for restoration of weight bearing and movement is established on an individual basis, with due regard to the purposes of the external fixation, the type of pathology treated, the segment, the age of the patient, the specifics of the patient’s somatic and local status, and the biomechanical characteristics of the fixation device used. Usually, on the first day after the external fixation, isometric exercises and active–passive movements of the fingers or toes and the wrist or ankle are recommended. In order to prevent the development of pin-induced joint stiffness, providing the rigidity of the bone fragment fixation allows, exercises therapy is started as early as possible, generally 2 or 3 days after the operation. However, if concomitant muscle injury is present exercises with minimum load are recommended, placing emphasis on passive movements. Exercise therapy is combined with breathing exercises, and general health-improvement measures which are very important for elderly and senile patients. For the first 3 or 4 days the exercises can be carried out in the ward, under the guidance of an exercise therapist. Each exercise session is 20–30 minutes with one or two sessions per day. Exercises should include passive and active movements in adjacent joints. On the third or fourth day, the exercises are transferred to the gym and the duration is increased to 45–60 minutes.As the acute postoperative events ameliorate, mechanotherapy is started using special equipment.Light massage is also beneficial.At the same time, the patient must understand that exercise therapy under the supervision of a specialist cannot alone lead to restoration of the extremity function, and that such therapy is not the end of the rehabilitation process. The exercises mastered should form the basis for independent effort aimed at restoring the lost potential for of self-support and working skills. After external fixation of a leg weight bearing is recommended from the first days after the operation. The procedure for selecting the individual load is as follows. The patient is asked to balance on the treated leg on the ﬂoor, and the load is gradually increased until some discomfort is felt (pain, sensation of tissues tension at the wires etc.). That load is taken as the initial load and is recorded in the patient’s medical record. Thereafter, the increments in weight bearing are monitored weekly. Restoration of a correct gait is also an important consideration. To allow the patient to make a step with the treated leg and then set against it the other leg is a gross methodological error. Special attention should be given to equal steps. In the first days the patient should be encouraged to make small steps, equal in length,

307

i.e. when making the next step, to set the heel at the level of the toe. The step length will gradually increase to the length it was before the trauma. An important element in the biomechanics of the gait is “the phase of rolling over the ankle joint”.Therefore,avoidance of pes equinus and early restoration of rear ﬂexion of the foot are necessary. For this purpose, a foot-support is used (Fig. 1.10.1). It is a mistake to use a rigid sole-shaped foot-support because it would impede the rolling over of the foot.

2.17.5

Physio- and Pharmacotherapy

Participation of a physiotherapist and clinical pharmacologist in working out the different components of the rehabilitation protocol is essential. A complex rehabilitation protocol is necessary when the patient shows pronounced oedema of the soft tissues of the injured extremity (increase in circumference at any level by more than 40–60 mm), tension in the soft tissues, change in skin colour, asymmetry in the rheological indices of the two extremities by more than 40%, and a shift in the haemostasis value towards hypercoagulation. Pharmacotherapy involves drugs that improve the rheological properties of the blood, microcirculation,tissue oxygenation,and vasoconstriction.Types of treatment include laser treatment, UHF therapy, magnetotherapy, light therapy and reﬂex therapy. The protocol is used for 7–10 days, with dynamic monitoring of efficiency and the required correction. Decisions as to whether the treatment should be stopped, continued or modified are based on dynamic clinical data (pain, oedema, skin colour, function of the extremity), functional test indices and biochemical tests.

2.17.6

Biomechanical Device State

The main discussion of the different biomechanical devices is presented in the sections on the treatment of fractures, malunions, nonunions, deformations, and long-bones defects. In this section we expand the previous discussion. At least once every 3 weeks it is necessary to check the tensioning of the wires by one of the following means: using a wire tensioner or traction clips,or tightening the wire fixing nuts (Figs.1.11.5 and 1.11.6).In the latter case bone fragments may become displaced if the wire fixation point on the support is displaced. Wires with a stop should be tensioned with two wire tensioners simultaneously. Maintenance of wire tension in the Ilizarov apparatus is particularly important and more important than in combined wire–pin assemblies. Of great significance is maintenance of the biomechanical state (distraction, compression and neutral forces) required at that specific moment, both between

308

2 Specific Aspects of External Fixation

the supports of the device and between the modules, for fixing the bone fragments. When performing any manipulations involving displacement of the external supports, it is necessary to place control marks on the connecting rods, e.g. narrow strips of adhesive plaster. Such marks are also placed on the traction wire clips with arrows showing the direction of nut rotation. The patient should also have a diagram of the external device indicating the rods that are used to carry out distraction or compression and the manipulations that have to be performed and their magnitude. It would be a grave error to carry out longitudinal compression of bone fragments with oblique or helical ends.10 In such cases it is necessary to perform contrary-lateral compression by means of transosseous elements (Figs. 1.6.9 and 1.6.10), or via the mutual displacement of the modules fixing the bone fragments (Figs. 1.6.4 and 1.6.5).Average compression in fractures is 1 mm over 10–14 days. In external fixation of metaphyseal fractures or compression arthrodesis of the large joints, the fragment ends are brought into close contact for 3–5 days. Primary vascular lacunae need to form at the site of contact. Thereafter, compression is carried out at a rate of 0.25 mm two or three times a day for 7–10 days. After a pause of 5–7 days, a radiograph is obtained. After arthrodesis, compression is, as a rule, continued at a rate of 0.5 mm a day for 4–7 days, and then supporting compression of 1 mm over 7–10 days [68]. In neutral external fixation (e.g. fragmented fractures) it is advisable to apply the tension in the modules fixing the bone fragments. For this purpose the supports that fix one bone fragment are brought together by 1 mm once in 3 weeks, and the external supports, that fix the second bone fragment are moved apart by the same distance. The rate and magnitude of distraction can vary not only with different pathologies but also over time during treatment of the same patient.A magnitude of 1 mm a day in four stages (0.25 mm four times a day) is accepted as the gold standard in external fixation. Rotation of an M6 nut by 90◦ corresponds to a movement of 0.25 mm. Better conditions for the formation of distraction regenerate will be obtained using automatic high-rate distracters [24, 25, 59, 64]. The first two or three days are taken up with bending the transosseous elements, especially in devices based on wires. Later, the increase in distance between the bone fragments should correspond to the rate of distraction, which is estimated from marks on the connection rods. 10

In such cases it is more appropriate to refer to the external supports being brought together leading to the bone fragments “sliding off” one another rather then compression.

It should be noted that the magnitude of distraction (compression) is the same as the change in the distance between the bone fragments. Therefore, in those cases in which a triangular regenerate is formed,monolateral distraction of the external supports by 1 mm does not lead to lengthening of the regenerate base by the same value (Fig. 2.8.17). Similarly, when tractionguiding wires are inserted at an angle to the displaced bone fragment (oblique-wire bone transport) are used, displacement of the traction clip by 1 mm leads to lengthening the regenerate by a smaller amount. To ensure a preset rate of distraction, skiagrams are used to carry out the special calculations given in the sections discussing open injuries and deformities of the femur and lower leg, and in the specialist literature [4, 26, 29, 36, 68]. In malunited fractures the distraction to reduce the bone fragments is started after 3–5 days at a rate of 0.75–2 mm a day depending on the fracture location (metaphysis, diaphysis), the time elapsed since the trauma (p. 196). Distraction of a tight nonunion with the aim of forming a distraction regenerate is carried out at the lower rate of 0.25 mm one to three times a day monitored by biochemical testing [69]. To form a distraction regenerate, displacement of bone fragments after corticotomy is started after 5– 7 days. After open osteotomy the distraction is started after 10–14 days [128]. In children the rate of distraction can be increased to 1.25–1.5 mm a day and decreased in elderly patients to 0.5 mm. When replacing a bone defect by lengthening both fragments (polylocal distraction-compression external fixation, or bilocal bone transport), the rate of distraction at the distal regenerate is, as a rule, 0.25–0.5 mm less than at the proximal bone fragment. After V- and Y-shaped foot osteotomy the distraction is started after 3 days at a rate of 0.25 mm four to eight times a day [98]. The absence of pain and neurotrophic disturbance and satisfactory functioning of adjacent joints are indicators of a favourable reparative course of osteogenesis processes including tension and lengthening of the soft tissues. The amount and rate of distraction are monitored using radiography,densitometry and ultrasonography, and biochemical testing is carried out monthly [24, 26, 36, 69, 90, 129–132]. The period after formation of the distraction regenerate is termed the “fixation period”. To maintain the rigidity of the osteosynthesis support distraction of 1–2 mm is performed in one stage over 7–10 days. It is recommended that the distraction regenerate is increased in thickness by an amount equal to its “growth zone” (5–10 mm). The supports are then brought together in a single step by the amount of that additional lengthening. This method, developed at the Russian Ilizarov Scientific Center “Restorative Traumatol-

2.17 General Principles of Patient Management in the Postoperative Period

ogy and Orthopaedy”, leads to a significant reduction in the time needed for reconstruction of a distraction regenerate [24, 26]. Distraction for reducing old dislocations or removing joint contractures is started after 3–5 days at a rate of 1.5–2 mm a day, in six to eight steps. The magnitude of distraction should be reduced and the number of manipulations increased when pain or symptoms of tension in the vessels and nerves occur [101]. Exercise therapy, physiotherapy and monitoring of the biomechanical status of the device are the most important components of the complex of restorative treatment in patients after external fixation. Generally, 2–3 weeks lack of monitoring the biomechanical status of the device and the dynamics of extremity function restoration should be considered a treatment error.

2.17.7

Outpatient Treatment

After external fixation of closed fractures, the ambulant regimen can begin after 3–5 days (and sometimes earlier). In patients with prolonged correction of fragment position (removal of deformity, replacement of a bone defect, segment lengthening etc.) and continuing presence of the wound, the timing of the transfer to the outpatient treatment regimen is determined individually. So, when lengthening the segment or replacing a segment defect, patients should have a radiographic examination after 7–10 days of distraction. Correspondence between the distraction rate and the regenerate length and coaxial separation of the fragments are important factors in allowing a patient’s discharge from the hospital. After discharge a nurse will examine the patient every 7–10 days and change the dressings. At least once a month the patient should consult the doctor who controls the postoperative regimen. During outpatient treatment the involvement of the surgeon who performed the operation is also essential. At home the patient follows, under the supervision of an attending doctor, a course of rehabilitation to ensure self-support, to restore the ability to work and to carry out domestic tasks (cooking, cleaning, ironing), and to enable re-engagement in hobbies (playing musical instruments etc). Students can return to their studies, and those in nonmanual employment can return to work. Elderly patients after external fixation of the arm, forearm or lower leg, as a rule, can fully attend to themselves and do not require the continued support of carers. The rehabilitation regimen after external fixation of the femur is somewhat more limited. Later, in accordance with the clinical and radiographic findings, the loading of the extremity is increased so that by the end of the fixation period weight-

309

bearing is 70–100% of the normal functional level (Figs. 2.17.2–2.17.4). Partial reassembling of the frame is considered as a technology component in external fixation. So, when soft tissues are cut through, the replacement of wires, strung on the external support (“cross-wire bone transport”), by the traction-guiding wires (“reins-wires” in “oblique-wire bone transport”) is the term for successful displacement of the bone fragment in case of bilocal replacement of the large bone defect (Figs. 2.10.5 and 2.10.6). After the deformity has been corrected, hinges may be replaced by connection rods or additional reductionally-fixing transosseous elements may be inserted. Furthermore, nonsystematic and disorganized manipulations, a lack of care in the initial planning, and arrangement of a device such that errors can be corrected later are unacceptable practices. The order of all manipulations should be planned in advance and documented in the medical records. Exceptions to this planned approach are when a wire needs to be reinserted because of pin-tract infection or a defective component of a device needs to be replaced, and similar situations requiring urgent attention. Most of the above-mentioned manipulations can be carried out in the out-patient department. Another example of changing the arrangement of a device during the period of fixation is modular transformation, which is a component of CEF.As mentioned in section 1.7, the modular transformation of an external device is planned in accordance with the weightbearing capacity of the bone regenerate, with the potential to gradually reduce the number of transosseous elements, connection rods and supports without insertion of additional transosseous elements, and with the amount of change in the geometry of the external support following removal of a part of the support. The aims of modular transformation are to optimize the conditions for bone wound healing (Ilizarov’s phrase“training the regenerate”; “dynamization”of the frame), reduce the risk of pin-induced joint stiffness and pin-tract infection, and make the treatment less uncomfortable for the patient by making the device less bulky. Following fixation of fractures, weight bearing in 5–8 weeks is in the range 50–70% of body weight – the patient can walk with one crutch. There is generally no oedema of the soft tissues; but if there is any it does not exceed 1–2 cm above and below the level of the fracture. The range of motion in the adjacent joints is being restored. Radiographs obtained during this period show fine periosteal regenerate over the surface of the fragment ends, with a density exceeding that of the soft tissues. There is pronounced endosteal regenerate rarefaction of the cortical plate (fibrosis of the cortical layer). The presence of these

310

2 Specific Aspects of External Fixation

a

b

c

d

e

f

Fig. 2.17.2a–f. Function of the arm after external fixation of a diaphyseal fracture (a, b) and nonunion of the humerus (c, d;, and after CSF of a nonunion of the humerus (e, f)

clinical and radiographic signs indicates that the basic supports of the device can be removed (Figs. 2.2.5b, 2.2.8b, 2.2.10b, 2.2.12b, 2.2.15b, 2.4.7b, Fig. 2.4.10b, 2.4.12b, 2.14.4b, 2.5.6b, 2.5.8b, 2.5.10b, 2.5.11b, and 2.17.4d).

In 9–11 weeks from surgery weight bearing has increased to 70–100% – the patient can walk with a walking stick. Movements in the knee and ankle joints are not limited. Clinical testing of the union shows the presence of a tight bond. Radiography shows an

2.17 General Principles of Patient Management in the Postoperative Period

a

b

c

d

311

Fig. 2.17.3a–t. Function of the arm after CEF of a Monteggia fracture (a–d), a nonunion of the ulna (e–h), and a deformity of both forearm bones (i, j). k–t Function of the arm after CSF of an ulna fracture (k–n), a malunited fracture of both forearm bones (o–r), and a defect of the soft tissue and the ulna (s, t)

312

2 Specific Aspects of External Fixation

e

f

g

i Fig. 2.17.3a–t. (cont.)

h

j

2.17 General Principles of Patient Management in the Postoperative Period

k

m Fig. 2.17.3a–t. (cont.)

l

n

313

314

2 Specific Aspects of External Fixation

o

q

s Fig. 2.17.3a–t. (cont.)

p

r

t

2.17 General Principles of Patient Management in the Postoperative Period

a

315

b

c Fig. 2.17.4a–m. a–f Function of the lower extremity after CEF of a nonunion of the femur (a–c), and a traumatic coxa vara with the femur shortened by 11 cm (d–f). g–m Function of the lower extremity after CEF of a segment fracture of the tibia (g–l), and splintered fractures of the femur and lower leg bones (k–m)

316

2 Specific Aspects of External Fixation

d

f Fig. 2.17.4a–m. (cont.)

e

2.17 General Principles of Patient Management in the Postoperative Period

g

i Fig. 2.17.4a–m. (cont.)

h

j

317

318

2 Specific Aspects of External Fixation

k

m Fig. 2.17.4a–m. (cont.)

l

2.17 General Principles of Patient Management in the Postoperative Period

increase in density of the periosteal regenerate with structural conversion into bone. In the interfragmentary gap single longitudinally oriented shadows of the new-built bone regenerate are seen, and there are the initial signs of the formation of a common cortical plate. The presence of these signs indicate that sectors of the reductionally fixing supports can be removed (Figs.2.3.7b,2.3.9b,2.3.11b,2.4.8b,2.4.13b,2.5.4b,2.5.6c, 2.5.8c, 2.5.10c and 2.17.4c). Similar clinical and radiological data are used to decide upon modular transformation in patients with nonunion or deformation of the long bones (Figs. 2.7.2, 2.7.3, 2.8.22, 2.9.2, 2.9.5, 2.10.1, 2.10.2, 2.10.3, 2.14.11, 2.17.3b and 2.17.4b). If necessary (for example, for insertion of additional transosseous elements or partial reassembly of the device) a patients can be hospitalized again for a short time.

2.17.8

Device Removal

There are three levels of strength of bone fragment unions: stabilized, strong and final [133]. In stabilized unions the strength of the bone callus ensures the absence of pathological mobility, but slight mobility (where the fragments have become bonded) still occurs in the fracture zone. Establishment of this level of union, according to the recommendations of the Russian Ilizarov Scientific Center “Restorative Traumatology and Orthopaedy”, indicates that the device can be removed. Such conditions are generally found in external fixation of the humerus or forearm bones. When a strong union has been achieved, 1–2 months after removal of the device, the strength of the callus is such that the patient can return to work without limitations. When a final union has been achieved, 1.5–2 years after the trauma in diaphyseal fractures, the coarse bundle of bone callus with a low strength has been replaced by lamellar bone. Clinical testing of the strength of the bone fragment union is carried out 10–14 days before the intended day for removal of the device. Before the testing, the modules fixing the proximal and distal bone fragments are left unattached for some time. The degree of mobility of the bone fragments is then determined by testing the ability to maintain the extremity in the horizontal position, and by manually applying lateral, axial and torsional loads. When no pathological mobility is seen, the connection rods are reattached and the device is “dynamized” by slackening the nuts of the connection rods of the intermediate support(s) by 1–2 mm. In CSF the dynamization is carried out by reducing the tension of the axial compression wire. Earlier dynamization of the frame (3–5 weeks before the intended day for removal of the device) is also known. For enable this, in order to “train” the regenerate some transosseous ele-

319

ments are removed in stages, some external supports are removed, and spring-loaded connection rods are used etc. This type of procedure is the basis of modular transformation, which is discussed above. In conclusion, we can say that there are two approaches to determining when the device can be removed. First, the device is removed in the presence of a stabilized union. In such cases, the weight-bearing by the extremity is considerably reduced. Whether a plaster support or brace is used is decided on an individual basis. Second, the device is removed when a strong union is present. In such cases, reduction in weightbearing by the extremity is insignificant after removal of the device. The patient should be involved in the decision as to which approach is adopted: to continue fixation with the device (with some continuing inconvenience) or to remove the device earlier (with the initial limits to activity) [134]. It should be noted also that the period of fixation with an external device is established individually, on the basis of dynamic clinical and radiographic monitoring.Normal skin colour,absent or insignificant oedema,painless movement of the joints,positive clinical testing for union, and absence of negative dynamics after “dynamization” of the device are clinical criteria for device removal. The presence of a radiographically visible fracture line and the absence of pronounced periosteal regenerate in the presence of the listed signs of union are not contraindications for device removal. Computed tomography can be used to resolve uncertain cases. Methods for the quantification of restoration of the mechanical strength of bone on the basis of biomechanical, laboratory, optical, electrophysiological, radiological and other kinds of monitoring are currently the subject of intensive development.Unfortunately,for various reasons, at the time of publication of this book, none of the widely known approaches and methods was in clinical use. Therefore, in uncertain cases we should be guided by the principle: “Better one month late than one day early”. Table 2.5 gives average periods of fixation and treatment for external fixation of fractures according to the data of the Russian Ilizarov Scientific Center “Restorative Traumatology and Orthopaedy” [4, 25, 127, 133, 135–137]. The period for fixation of a pseudoarthrosis mainly depends on the initial type of bone formation,the shape of the bone fragment ends and the degree of their devitalization,and is in the range 2–3 to 5–6 months.Longer periods for fragment consolidation should be expected if nonunion occurs after bone osteosynthesis. Union of an arthrodesis takes place in 2–4 months. During formation of distraction regenerate, the fixation index (number of days for fixation of the formed

320

2 Specific Aspects of External Fixation

Table 2.5. Average periods of fixation and treatment (days) in Ilizarov external fixation Location and type of fracture

Period of fixation

Period of treatment

Closed fractures of the proximal humerus (11-A, 11-B)

22–27

46–51

Closed/open diaphyseal fractures of the humerus (12-A, 12-B, 12-C1)

39–66/49–73

85–118/109–156

Closed fractures of the distal humerus (13-A, 13-B)

18–25

32–53

Closed fractures of the proximal forearm bones (21-A, 21-B)

25–47

39–89

Closed/open diaphyseal fractures of both forearm bones (22-A3, 22-B3)

49–67/88–117

100–115/124–152

Closed/open diaphyseal fractures of the ulna (22-A1, 22-B1)

50–67/65–82

77–94

Closed/open diaphyseal fractures of the radius (22-A2, 22-B2)

48–59/62–77

80–96

Closed fractures of the distal forearm bones (23-A, 23-B)

18–37

32–58

Closed fractures of the proximal femur (31-A, 31-B)

50–53

155–186

Closed/open diaphyseal fractures of the femur (32-A, 32-B)

62–92/77–92

109–154/189–229

Closed fractures of the distal femur (33-A, 33-B, 33-C1) and the proximal lower leg (41-A, 41-B, 41-C)

46–52

78–88

Closed/open diaphyseal fractures of the lower leg (42-A, 42-B)

60–82/101–121

97–122/151–169

Closed fractures of the ankle (44-B, 44-C)

51–57

106–116

regenerate divided by the length of the regenerate in centimetres) should not exceed 25–30. Devices are generally removed in the out-patient department. To remove wires with stops and half-pins local anaesthesia is sometimes required. In children and psychologically unstable patients a sedative is also required, and induction of brief narcosis may sometimes also be required. First the basic transosseous elements are disconnected from the external supports. Then the reductionally fixing wires and half-pins are disconnected. To avoid causing pain by the sudden release of tension in a wire, the tension should be eliminated before the wire is cut off at the level of the skin. After removal of the transosseous elements, the wounds are treated with antiseptics and covered with a sterile dressing. The patient can take a hygienic bath only after the skin wounds have healed and not earlier than in 10–14 days after removal of the device. After removal of the device weight bearing should be decreased and then gradually increased up to the functional norm. Again the advisability of using plaster bandages and braces during this period is established on an individual basis. Patients with a device

mounted on the ankle or foot should be advised to use an orthopaedic insole for 6 months after removal of the device.

2.18 Mistakes and Complications of External Fixation External fixation devices are more complicated engineering constructions than implants. Therefore, external fixation has more nuances than any other method of osteosynthesis. So the surgeon must know how to avoid possible mistakes and complications. The percentage of complications in external fixation presented in the literature (1.5% to 100%) gives occasion for discussion which still continues. The complications can be divided into those inherent at the stage of performing the operation and those inherent in the postoperative period during the period of fixation and after removal of the device. In some cases different mistakes and complications can lead to the same results.

2.18 Mistakes and Complications of External Fixation

Table 2.6 shows some complications, the causes of their development, and the principles involved in their avoidance and treatment. If conservative treatment of pin-tract infection for three or four days is ineffective, the transosseous element should be removed. In the presence of concomitant diabetes more active tactics are used: wide opening of the wire channel, drainage, antiseptic dressings, and treatment with antibiotics (with due regard for sensitivity), enzyme drugs, or a solution of insulin and glucose. According to indications, dressings with a watersoluble ointment are put on the wound. Optimum insulin therapy is supplemented with the use of albumin drugs, anabolic hormones, angioprotectors and immunostimulants [137]. Special attention also should be paid to wires inserted near the zones of growth. How the frame can be stabilized by insertion of additional wires (half-pins) is resolved on an individual basis. The ill-timed removal of a wire can lead to the socalled “pin-tract osteomyelitis”. Another cause of this complication is bone burn resulting from insertion of a wire with inadequate sharpness and/or from the use a high-speed drill. Usually, the course of pin-tract osteomyelitis is not malignant, and it often shows spontaneous remission. If resistance occurs surgical excision of the annular sequestrum may be necessary. Inﬂammation of the soft tissues near transosseous elements inserted near joints can result in arthritis. In such cases the injured joint is stabilized by mounting on an additional transosseous module or with a plaster bandage in addition to the external fixation device, and then the wires inserted through the epiphysis (epimetaphysis) are removed. Arthritis is treated by the usual method with due regard to peculiarities of the disease course. When a nerve trunk is damaged by a wire or there is neuritis caused by pressure from a transosseous element, the element should be removed. In such cases treatment is generally conservative in consultation with a neurologist. Symptoms of biologically active infection in association with wires have been reported, including dermatitis, oedema and pain, which do not respond to conservative treatment. Idiopathic conditions such as prolonged intermittent fever, heart pain and disturbances of digestion have also been reported [15, 105, 138, 139]. Consultation with a reﬂex therapist, or removal or displacement of one or two wires are recommended.

321

Wires cutting into the soft tissues mostly occurs during distraction and cross-wire bone transport. This complication is generally cured in two stages. In distraction of up to 4–6 cm (depending on the segment) the releasing the soft tissues is sufficient. Later, reinsertion of the transosseous elements is required. The use of oblique-wire bone transport or an axial distraction wire (Fig. 2.6.6) allows the risk of developing this complication to be reduced. If the soft tissues are damaged by movement of the joint, the skin should be incised the necessary amount. It is important to recall that the diameter of the half-pin must not exceed 20% of the bone diameter at the level placement so that the mechanical strength of the bone is not decreased [140]. If pin-hole fracture occurs reassembly of the device or, rarely, a change of the fixation method is necessary. To avoid resistant joint contractures the segment should not be lengthened in one stage and should not exceed a certain critical value that is determined individually with due regard to the segment being lengthened, the type of pathology and the method used. In particular, lengthening by more than 15% of the initial segment should not be attempted if before treatment there was moderate limitation of the range of motion in the adjacent joints.A decrease in the range of motion by an average of 50–60% of the initial value is the limit. It should be remembered that the closer to the joint the transosseous elements are inserted or the closer to the joint corticotomy is performed, the greater is the risk of development of contracture. In case of bilocal lengthening of the lower leg, after formation of a distal distraction regenerate of more than 20–30 mm there appears to be an increased risk of development of the equine foot position,even when all avoidance measures are taken. This is an indication that the rate of distraction should be reduced to 0.25 mm once or twice a day or even stopped. Residual shortening should be compensated for by formation of the proximal distraction regenerate. The main way to avoid mistakes and complications in external fixation is to follow the advice of Ilizarov [141]: “A surgeon should know not only the device but also the method proposed with it, therefore its detailed mastering is a must”. Indeed, it is easy to verify that most mistakes and complications occur because of failure to follow the methods of external fixation and to take into account the knowledge of the biomechanics of external fixation, and because of omissions made during the postoperative period.

322

2 Specific Aspects of External Fixation

Table 2.6. Complications of external fixation Complication Inflammation of soft tissues around transosseous elements (pintract infection)

Main causes Violation of asepsis and rules of antisepsis

Chronic trauma of the soft tissues caused by the transosseous elements

Instability of the modules of the external device or the device overall Necrosis of soft tissues (caused by pressure of external supports and other device elements)

Use of external supports of inadequate size

Excessive pressure from rubber protection stops fixing gauze dressings on wires

Prophylaxis Strict observance of asepsis and rules of antisepsis during insertion of transosseous elements and application of dressings; regular of dressing changes The use of positions involving minimum displacement of soft tissues during insertion of transosseous elements; elimination of tension of soft tissues Measures to maintain device stability

Treatment Local administration of antibiotics with due regard for the sensitivity of the microflora; laser, UV or UHF therapy

Arrangement of device supports with due regard to the possibility of increasing the length of the segment circumference by 4–6 cm. Eccentric arrangement of supports with room for the tissues where oedema is most likely When there is the risk of oedema, use rubber protection stops of greater internal diameter so that the stop moves freely over the wire

In an emergency when there is risk of pressure, a flat spacer can be placed between the ring and the skin; elevation of the extremity; antioedema therapy

Cutting of the soft tissues to release tension

Restoration of stability of the modules and the frame

Partial reinstallation of the device

Necrectomy (if necessary), local treatment of the pathological process Injury of main vessels and nerves

Insertion of transosseous elements in the projection of vessels and nerves

Winding of soft tissues on the wire

Use safe and reference positions for insertion of wires and half pins; use preliminary contrast vasography, MRT in difficult cases. Half-pin insertion control in the presence of vessels and nerves beyond the second cortical plate Use wires with a polished surface; use a conductor

Removal of the transosseous element and compression haemostasis; suturing the vessel (if necessary)

Bleeding caused by a bedsore is treated surgically (ligature, vessel reconstruction)

2.18 Mistakes and Complications of External Fixation

Complication

Main causes

Prophylaxis

Treatment

Dermatitis

Dressings with drugs causing an allergic reaction Reaction to infection, inflammation of soft tissues around transosseous elements (microbial eczema)

Elimination of the allergen

Elimination of the allergen

Timely diagnosis and treatment of the inflammatory process

Stopping the inflammatory process

Topical glucocorticoid treatment of wound surfaces; desensitization, detoxification therapy Consultation with a dermatologist Neurovascular disorders

Generally, exceeding the rate of distraction (compression)

Control the rate of change of the spatial orientation of the bone fragments Use automatic highfractional distractors

Contractures (pininduced joint stiffness)

Insertion of the transosseous elements where displacement of soft tissues relative to the bone is great Disregarding the method for changing the extremity position such that soft tissue is displaced during wire insertion

The use of closed external supports (rings) close to joints Tension in soft tissues because of distraction (when lengthening a segment)

The use of reference positions for wires and halfpin insertion

Formation of a soft tissue “reserve” by correct positioning of the extremity when inserting the transosseous elements through “flexion” and “extension” surfaces of the segment; manual displacement of soft tissue The use of nonclosed external supports (half-rings, two-thirds rings) near joints To avoid hard contractures, the segment should not be lengthened in one stage more than a certain critical amount

Increase the number of distraction steps (e.g. from 0.25 mm four times to 0.125 mm eight times) Decrease the rate of distraction or temporarily stop distraction (compression) Drug treatment, physiotherapy Intensive exercise therapy

The use of special modules in the device that increase the range of movement

Replacement or removal of transosseous elements

Reducing the rate of or stopping segment lengthening

323

324

2 Specific Aspects of External Fixation

Complication

Faulty position of joints, subluxations

Main causes

Prophylaxis

Disregarding additional measures for contracture prophylaxis

The use of special positions for the extremity after surgery; also using devices attached to the apparatus. Active-aggressive postoperative rehabilitation; daily maintenance of movement amplitude preset on the operating table during the entire fixation period instead of increasing the range of movement after the contracture has appeared

Treatment

Violation of the segment lengthening method (including inadequate magnitude of lengthening and rate of distraction; errors in the apparatus assembly) Disregarding prophylactic measures for this complication

Strict observance of the osteosynthesis method

Stopping the distraction

Taking preventive measures (e.g. temporary fixation of the joint with a transosseous hinge module)

Partial reinstallation of the device (if necessary)

Mounting of an additional transosseous module to correct the complication Arthrolysis, lengthening the tendons (according to indications) Secondary bone fragment displacement

Breakage of a transosseous element or failure of a device unit

Biomechanical fundamentals of the device mounting and reduction and fixation of bone fragments are not used or ignored Failure of device units

The patient’s range of movement, condition of the segment and the frame are not monitored Overloading of the frame– extremity system

Strict observance of biomechanical standards

Generally, partial reinstallation of the external device

The use of high-quality certified equipment; observance of rules for storage, sterilization and disinfection of the device. Adequate monitoring of the patient

Care during the device mounting (including wire tensioning); loading on the extremity should correspond to the weightbearing capacity of the bone callus, rigidity of bone fragments fixation, ensured by use of an adequate device assembly

Replacement of defective unit, partial reinstallation of the device

2.18 Mistakes and Complications of External Fixation

Complication

Cutting into the bone with transosseous elements

Patient’s psychological inability to tolerate external fixation treatment

Main causes

Prophylaxis

Defect in the metalwork or metal fatigue Rules for storage, sterilization and disinfection of the device are not observed resulting in e.g. corrosion, deformation, loss of mechanical properties due to sudden temperature changes Edge insertion of transosseous elements

The use of high-quality certified equipment. Observance of the rules for storage, sterilization and disinfection of the device

Insufficient area of the wire stop in relation to the load used and the degree of osteoporosis The use of half-pins in pronounced osteoporosis

Increase the number of the transosseous elements and use wire stops of sufficient area Use only wires with stops in pronounced osteoporosis

Underestimation of the patient’s psychological condition before treatment. Critical circumstances in the patient’s life making the further use external fixation devices impossible

Taking into consideration all contraindications for the use of external fixation

Insertion of transosseous elements through two cortical plates, except in special cases

Treatment

Replacement of the transosseous elements (when it is necessary to retain the initial number of transosseous elements and the degree of bone fragment fixation rigidity)

Consultation with a psychotherapist

Sedative therapy Removal of the device if absolutely necessary and the use of another method of bone fragment fixation Malunion or nonunion, or formation of a hypoplastic distraction regenerate (open or closed segment injuries resulting from highenergy injuries are not considered here)

Absence of exact reduction of the bone fragments; secondary displacements

Ensuring exact bone fragment reduction (adaptation); prophylaxis of secondary displacements

(Gradual) bone fragment reduction

The frame used could not provide early restoration of range of motion and weight bearing

Use of external fixation device that ensures the rigidity of bone fragment fixation, adequate weightbearing capacity of the bone regenerate and early range of motion restoration

Ensuring adequate rigidity of the bone fragment fixation

325

326

2 Specific Aspects of External Fixation

Complication

Refracture, secondary deformity

Main causes

Prophylaxis

Premature removal of the device

Considering clinical and radiographic criteria before device removal

Bone union without restoration of the mechanical axis of the extremity Union over a limited area

Restoration of the biomechanical extremity axis

Primary union (without periosteal callus)

Treatment Use of special methods for optimization of reparative osteogenesis on the basis of biological, mechanical, physical, bioenergetic and pharmacological factors Conservative treatment, reosteosynthesis, reconstructive surgery (according to indications)

Exact reduction of fragments Decrease in weightbearing after removal of the device

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Kutepov SM, Stelmakh KK, Mineev KP, Shevalajev GA (1994) The technique of external fixation in patients with pelvic fractures (teaching aid). Ural NIITO, Ekaterinburg

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112. Ebraheim NA, Saddemi SR, De Troye RJ (1993) Results of Judet quadricepsplasty. J Orthop Trauma 7:327–330 113. Harner CD, Miller MD, Irrgang JJ (1994) Management of the stiff knee after trauma and ligament reconstruction. In: Traumatic disorders of the knee. SpringerVerlag, Berlin Heidelberg New York, p 364 114. Kaplan AV (1967) The pathology of bone and joints. Meditsina, Moscow

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115. Makushin VD, Kamerin VK, Jugaj AE, Djachkova GV (1994) Surgical treatment of posttraumatic extension contracture of knee joint (methodological recommendations). RSC “RTO”, Kurgan

130. Desyatnichenko KS, Grachjova LI, Kuznetsova LS (1990) Functional biochemical studies in orthopedic surgery and traumatology clinics (methodological recommendations). RSC “RTO”, Kurgan

116. Reutov AI, Gyulnazarova SV, Myakotina LI (2000) About functioning of locomotor system of patients with lower extremity shortening associated with permanent limitation in the range of knee motions. Travmatologia i Ortopedia Rossii 1:45–49

131. Sveshnikov AA, Makhushin VD, Kuftirev LM et al (1991) Clinical-and-roentgenoradionuclide assessment of reparative osteogenesis at building of diaphyseal defects of crural and femur bones using Ilizarov’s method of lengthening of one of bone fragments (methodological recommendations). RSC “RTO”, Kurgan

117. Kornilov NV, Karptsov VI, Novoselov KA et al (1992) Comparative analysis of one- and two-stage methods of surgical treatments of femur pseudoarthrosis and malunions associated with knee joint contractures. In: Kornilov NV (ed) Planned surgical interventions (preoperative examination and patient preparation, complications, outcomes). RNIITO, Saint Petersburg 118. Klyushin NM (1998) Surgical external fixation in patients with chronic osteomyelitis (methodological recommendations). RSC “RTO”, Kurgan 119. Shevtsov VI, Lapynin AI, Klyushin NM (2001) The application of external fixation for treatment of patients with chronic osteomyelitis. Zaural’e, Kurgan 120. Ankin LN, Ankin NL (1994) The practice of osteosynthesis and prosthetic arthroplasty. Naukova Dumka, Kiev 121. Shapovalov VM, Ovdenko AG (2000) Gunshot osteomyelitis. Morsar, Saint Petersburg 122. Nikitin GD, Rak AV, Linnik SA et al (2000) Surgical treatment of osteomyelitis. Russkaya Graphika, Saint Petersburg 123. Vinogradov VG (2000) Outwards bone repart in complex treatment of chronic osteomyelitis of lower extremity bones. Irkutsk University Press, Irkutsk 124. Aranovich AM, Lapynin AI (1994) The treatment of patients with osteomyelitic cavities (methodological recommendations). RSC “RTO”, Kurgan 125. Kolomiets AA, Raspopova EA (1997) The osteosynthesis by Ilizarov’s apparatus. Altaian Polygraphic Centre, Barnaul 126. Ilizarov GA, Devjatov AA, Shved SI (1979) External fixation of diaphyseal femur fractures in elderly and old persons (methodological recommendations). RSC “RTO”, Kurgan 127. Shevtsov VI, Makushin VD, Kuftirev LM (1997) Treatment of congenital non-unions of tibial bones. Zauralye, Kurgan, 255 p 128. Yerofeyev SA (2003) Experimental substantiation of the modern technology of extremity lengthening (dissertation). RSC “RTO”, Kurgan 129. Baldin YuP, Desyatnichenko KS (1991) Assessment of the process of reparative osteogenesis (methodological recommendations). RSC “RTO”, Kurgan

132. Sveshnikov AA, Popkov AV (1991) Complex roentgenoradionuclide assessment at the lengthening of lower extremities (methodological recommendations). RSC “RTO”, Kurgan 133. Shevtsov VI, Shved SI, Sysenko YuM (2002) External fixation for the treatment of comminuted fractures. Dammi, Kurgan 134. Khrupkin VI, Artemiev AA, Popov VV, Ivashkin AN (2004) The use of Ilizarov’s method for the treatment of fractures of the shin bones. GEOTAR-MED, Moscow 135. Popova LA (1991) The terms of restorative treatment and temporary disability in patients with lower extremity fractures at their rehabilitation using Ilizarov’s method of external fixation (methodological recommendations). RSC “RTO”, Kurgan 136. Popova LA (1994) Organization of examination and a substantiation of terms of disability in treatment of bone fractures using Ilizarov method (methodical recommendations). RSC “RTO”,Kurgan 137. Shved SI, Sisenko JM, Novichkov SI (1997) Transosseous using Ilizarov’s method at the treatment of long bone diaphyseal fractures of upper extremities in patients with insular diabetes (methodological recommendations). RSC “RTO”, Kurgan 138. Ivannikov SV, Oganesjan OV, Shesternja NA (2003) External fixation for the treatment of forearm fractures. BINOM, Moscow 139. Mironov SP, Oganesjan OV, Zilov VG et al (2002) Reaction of an organism at insertion of external fixation devices wires in biologically active zones. N.N. Priorov Bulletin of traumatology and orthopedy 2:14–18 140. Vidal MJ (1968) Notre expérience du fixateur externe d’Hoffmann. Montpellier cbir 14:451–60 141. Ilizarov GA (1975) External fixation using the author’s device in acute trauma. Third All-Union Congress of Traumatologists and Orthopedists, Moscow, pp 148– 153 142. Oganesyan OV (2004) The basic foundation of external fixation. Meditsina, Moscow

Suggested Reading

Suggested Reading Artemiev AA (2003) The correction of shape and length of the lower extremities in reconstructive and aesthetic surgery (abstract of dissertation). CITO, Moscow Artemiev A, Mirzoyan A, Popov V (2004) Aesthetically indicated surgical correction of shape and proportion of the legs. In: Proceedings of the 3rd Meeting of the ASAMI International (abstract book). Istanbul, p 299 Barabash AP, Solomin LN (1992) Combined Strained Fixation of Long Bones. RIO, Blagoveshchensk Barabash AP, Solomin LN (1997) “Esperanto” of transosseous elements insertion at osteosynthesis using Ilizarov device. Nauka, Novosibirsk Behrens F (1990) External fixation: special indications and techniques. AAOS Instr Course Lect 39:173 Bianchi Maiocchi A, Aronson J (1991) Operative principles of Ilizarov: treatment of fracture, non-union osteomyelitis, lengthening, deformity correction. In: ASAMI Group (Association for the Study and Application of the Method of Ilizarov). Medi Surgical Video, Milan, p 579 Bliskunov AI, Leikin MG, Dzhumabekov SA (1996) The lengthening of femur using the Bliskunov apparatus with different kinds of osteotomy. Vestnik Travmatologii i Ortopedii n.a. Priorov 3:22–30 Chelnokov AN, Novitskaja NV, Gukov PV (2001) Osteosynthesis using the wire-pin and pin apparatus in the treatment of patients with diaphyseal fractures of the lower leg. Ural NIITO (Research-scientific Institute traumatology and orthopedy), Ekaterinburg De Basiani G, Apley AG, Goldberg A (2000) Orthofix external fixation in trauma and orthopaedics. Springer-Verlag, Berlin Heidelberg New York Devyatov AA (1990) External fixation. Shtiintsa, Kishinev Devyatov AA, Konstantinov BK (1979) External fixation using Ilizarov’s apparatus in patients with fractures of knee joint (methodical letter). RSC “RTO”, Kurgan Faddeev DI (1997) Early metal osteosynthesis in patients with closed and open multiple and combined fractures of the long bones. Printing house of the Smolensk Center of the Scientific and Technical Information, Smolensk Gafarov KhZ (1995) The treatment of children and adolescents with orthopedic diseases of the lower extremities. Tatar Book Press, Kazan Green SA (1981) Complications of external skeletal fixation: causes, prevention and treatment. Charles C. Thomas, Springfield

331

Ilizarov GA, Devjatov AA, Trokhova VG, Meshkov AN (1979) External fixation using Ilizarov apparatus for the treatment of femur defects in purulent infections (methodical letter). RSC “RTO”, Kurgan Ilizarov GA, Makhushin VD, Nemkov VA, Kuftirev LM (1990) Evaluation of the rational options for fragment lengthening by Ilizarov’s technique for the restoration of bone defects (methodical letter). RSC “RTO”, Kurgan Ilizarov GA, Shevtsov VI, Kaljalina VI, Skljar LV (1991) The treatment of children and adolescents with O-shaped deformities of the lower extremities (letter of recommendation). RSC “RTO”, Kurgan Kuftyrev LM, Kamerin VK (1994) Reconstructive-restorative operations based on controlling external fixation for femur defects. RSC “RTO”, Kurgan Kutepov SM, Runkov AV, Antoniadi YuV (1999) Surgical reconstruction of the shape and stability of the pelvic ring. In: Kluchevsky VV (ed) New implants and technologies in traumatology and orthopedics. The Yaroslavl State Medical Institute, Yaroslavl Lee AD (1992) External fixation in traumatology. Tomsk University Press, Tomsk Mears D (1979) The management of complex pelvic fractures. External fixation. Slack, Thorofare, NJ Mears D (1983) Skeletal external fixation. Williams and Wilkins, Baltimore Mineev KP (1993) Anatomical and surgical substantiation of external fixation of fractures of the bones of the extremities. Mordovian University Press, Saransk Mora R (2000) Tecniche di compressione-distrazione. Indicazioni e limiti. Amplimedical, Milano Per H (2001) The plastic surgery encyclopedia. Astrel, Moscow Popkov AV, Zyryanov SYa (1991) Surgical lengthening of the lower leg using Ilizarov’s method (methodological recommendations). RSC “RTO”, Kurgan Popkova LA (1994) The examination and estimation of disability in patients with fractures of the extremities treated using Ilizarov’s method (methodological recommendations). RSC “RTO”, Kurgan Popova LA, Djachkova GV, Gugkova NE (1987) Determination of the cost-effectiveness of new methods of treatment of orthopedic and traumatologic patients (methodological recommendations). RSC “RTO”, Kurgan Rubash HE, Mears DC (1983) External fixation of the pelvis. AAOS Instr Course Lect 32:329–348

Ilizarov GA, Smelyshev NN (1975) Compression arthrodesis of hip joint (letter of recommendation). RSC “RTO”, Kurgan

Runkov AV, Kutepov SM, Stelmakh KK et al (2001) The elimination of pelvic traumatic deformities. In: Kutepov SM (ed) Treatment of injuries and diseases of pelvic bones. Ural Research-scientific Institute traumatology and orthopedy, Ekaterinburg, pp 48–50

Ilizarov GA, Trokhova VG, Murashka VI (1978) Femur lengthening in patients with the hip fused in an incorrect position (methodical letter). RSC “RTO”, Kurgan

Ryf Chr, Weymann A (1996) The method of neutral zero position is the measurement principle of joint range of motion. Vestnik “Mathys” 2:6–7

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Ryf Chr, Weymann A (1996) The method of neutral zero position is the measurement principle of joint range of motion. Vestnik “Mathys” 3:3–7 Shevtsov VI, Shrejer AA, Borodajkevich RD (1993) The out-patient treatment of diaphyseal tibial malunions (methodologicalrecommendations). RSC “RTO”,Kurgan Shevtsov VI, Nemkov VA, Burlakov EV (1998) The rigidity of cantilever wires and pins during external fixation. Genii Ortopedii 1:45 Shevtsov VI, Karasjova TJ, Makushin VD, Teplenky MP (1998) Surgical treatment of patients with varus deformity of the femur neck using Ilizarov’s apparatus (methodological recommendations). RSC “RTO”, Kurgan Shevtsov VI, Aranovich AM, Borodeykevich RD (2003) Rehabilitation of patients with malunions of the bones of the lower leg. Dammi, Kurgan Shevtsov VI, D’yachkova GV, Alekbarov AD (2004) ErlacherBlount disease: diagnostics, treatment and prophylaxis of recurrences(methodological recommendations). RSC “RTO”, Kurgan

Shlykov IL, Kutepov SM, Runkov AV (1999) Applying perosseous osteosynthesis in treatment of old deformations of the pelvic ring. In: Proceedings of the Third European Congress of Trauma and Emergency Surgery, 15–17 September, Lyon Shlykov IL (2004) Surgical treatment of patients with the consequences of injuries to the pelvic ring (dissertation). RSC “RTO”, Kurgan Solomin LN, Andrianov MV (2004) Combined external fixation of diaphyseal femur fractures (New medical technology). RNIITO n.a. R. Vreden, Saint Petersburg Stelmakh KK, Kutepov SM, Lazareva NN (1998) Therapeutic exercises for patients with pelvic fractures following external fixation (methodological recommendations) Ural Research-scientific Institute traumatology and orthopedy, Ekaterinburg Stetsula VI, Veklich VV (2003) The foundation of directed external fixation. Meditsina, Moscow Tile M (1984) Fractures of the pelvis and acetabulum. Williams & Wilkins, Baltimore

3 Appendix 1: Method for the Definition of “Reference Positions” for the Insertion of Transosseous Elements 3.1

Introduction

“Reference positions” for the insertion of transosseous elements must comply with two most important requirements: minimum displacement of soft tissues during movement in the joints adjacent to the segment, and no risk of damage to great vessels and nerves. The use of positions with minimum displacement of soft tissues decreases the risk not only of pin-induced joint stiffness,but also of pin-tract infection because chronic traumatic injury to the soft tissues by the transosseous elements is reduced.When the displacement of soft tissues is not considered, the term “safe positions” is used. Thus, to find the reference positions it is necessary to determine positions with minimum displacement of soft tissues and then from these positions to eliminate those where the insertion of wires and half-pins could damage great vessels and nerves, i.e. “contraindicated positions”. Thus reference positions are positions with minimum displacement of soft tissues that are not forbidden (contraindicated) positions. For the exact designation of “reference positions”, “safe positions” and “contraindicated positions” a system of coordinates is used according to the method for unified transosseous osteosynthesis designation. The Method for the Unified Designation of External Fixation is described in section 1.8.

3.2 Main Principles for the Determination of Positions with Minimum Displacement of Soft Tissues Skin, fascia and muscle at the same level are displaced by different amounts. Therefore, this required component in defining a reference position is determined from cadaver experiments1 . The method involves determining the magnitude of the displacement of each soft-tissue layer (skin, fascia, 1

The method for determination of skin displacement in individual patients is given at the end of this appendix.

Fig. 3.1. Diagram of the device for determination of softtissue displacement. The device consists of two or three halfpins (1), to which a basic support (2) is rigidly fixed. Guides (3) are rigidly fixed to the basic support. There should be at least two guides in order to prevent rotational displacement of the control support. The control support (4) based on a half, three-quarter or full ring can move on the guides. Each guide is provided with thread, nut and lock nut. The control support is shown in greater detail in Fig. 3.2

muscle, tendons) using the device shown in Figs. 3.1 and 3.2. Its main features are its rigid fixation to the bone, rigid fixation of the guide to the basic support, precise orientation of the guides relative to the long bone axis, and the possibility of controlling the orientation of the positions under examination relative to the centre of the bone diameter. Because soft-tissue displacement decreases the further away from the joint where movements are occurring, the basic support is placed at the maximum distance from the joint. For example, when evaluating soft-tissue displacement during movements of the knee joint, the half-pins are inserted at the level of the proximal femur metaphysis. In order to fully eliminate the possibility of restricting soft-tissue displacement relative to the bone, radial full-depth incisions in the soft tissues as far as the bone are made in the half-pin insertion region. The basic support with rigidly fixed guides is fixed to the half pins. In doing this, the following conditions should be fulfilled: 1. The guides are oriented parallel to the anatomic bone axis.

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Fig. 3.3. Example graphs of soft-tissue displacement relative to the femur for flexion of the knee joint with an amplitude of 90/0 at level VII

Fig. 3.2. To the control support are rigidly fixed 12 tubes (1) located diametrically opposite each other in pairs, each with a fixing bolt (2). Into each guiding tube is inserted a feeler (3). When all feelers are inserted, their guiding ends meet in the support centre

2. The shortest distance at the same level of each guide to the bone diameter centre should be equal, i.e. the centre of the control support should correspond to the bone diameter centre at any point during movement of the support over the guides. To fulfill these requirements, well known tips such as roentgenograms, feelers etc. are used. For providing of these requirements well known tips, like roentgenograms, feelers etc. are used. The control support is then put on the guides and fixed with nuts and lock nuts at the level where evaluation of soft-tissue displacement is intended. The joint is placed in the “zero” position.

3.2.1

Skin Displacement Evaluation

A dye,e.g.a solution of brilliant green,is put on the feelers. All feelers in turn are moved to the bone up to the stop. Reference marks are left at the points where the feelers contact the skin and are shown as circles of dye. The feelers are removed from the skin and fixed with bolts. All the marks are then connected. The segment at the level of examination is wrapped with transparent material (tracing paper, clear plastic film etc.). The following step is transferring (copying) to clear plastic

film a curve 1 with a designation of all of 12 positions (according to the feeler number). Movement of the type under study is performed with maximum possible amplitude and the joint is fixed in a new position. Once more dye is put on the feelers, but of a different colour. The feelers are moved to the bone up to the stop. Where the feelers contact the skin and underlying soft tissue, the marks remain. The feelers are removed from the skin and fixed with bolts. All the new marks obtained are connected to form curve 2. Once more, the segment at the level of examination is wrapped with the same sheet of tracing paper (or clear plastic film) oriented such that the feeler ends of the control support exactly coincide with the feeler marks of curve 1. Curve 2 is transferred to the tracing paper. Thus, displacement of curve 2 relative to curve 1 shows the displacement of the skin relative to the “zero” position with the given movement of the joint. To facilitate data processing, both curves are transferred to graph paper. It is essential to retain the positional marks designated by the feelers because the bones of all the extremities are located eccentrically relative to the soft tissues and the distances between control positions are different. Therefore, it would be a mistake to divide the obtained “zero” line into 12 equal segments (parts). The above procedure is carried out to determine the displacement of the soft tissues for all movements. A separate sheet of graph paper should be used for each movement for convenience of the subsequent analysis. Thus, by the end of the first stage of the evaluation the number sheets of graph paper with the curves of softtissue displacement is equal to the number of movements evaluated.

3.3 Determination of Positions with Minimum Soft-Tissue Displacement

3.2.2

Fascia Displacement Evaluation

Skin and subcutaneous fatty tissue are removed from the segment under examination. The entire procedure described above is repeated, with the exception of transferring curve 1 (“zero” position, initial position of soft tissues) to the tracing paper and later to the graph paper. As a result, on each sheet of graph paper there should be three lines: zero, skin displacement and fascia displacement. The precision of the process is ensured by alignment of the extended feelers with the available control point marks.

3.2.3

Muscle Displacement Evaluation

In the next stage, the fascia is removed and some experiments on the muscles are performed. Separate curves can be obtained for different groups of muscles (superficial, deep etc.) and muscle tendons. Therefore, on the sheets of graph paper there should be a number of lines, equivalent to the number of experiments. As an example, Fig. 3.3. shows schemes of the soft-tissue displacement relative to the femur, in case of ﬂexion in the knee joint with the amplitude of 90/0 at the level VII. The data obtained are then analysed to determine the positions with minimum displacement of skin, fascia and muscles for a specific movement. In the next stage, the positions with minimum softtissue displacement for all movements in the given joint are determined. For example, at level II of the upper arm, the minimum displacement of soft tissues is determined: • For ﬂexion of the shoulder joint in the projection of positions 2, 3, 4, 8, 9, 10, 11. • For abduction of the upper arm in the projection of positions 8, 9, 10, 11. Thus, positions III,8; III,9; III,10 and III,11 have the minimum soft-tissue displacement for given movements of the shoulder joint at level II of the upper the arm. Finally,the positions with minimum soft-tissue displacement for all evaluated movements of the joints adjacent to the segment are determined. The following should be born in mind. As already mentioned, displacement of soft tissues relative to the bone decreases with increasing distance from the joint where the movement is occurring. So, at the level of the middle third of the segment the maximum amount of displacement is close to the minimum amount in the immediate vicinity of the joint. Thus, it may be conditionally assumed that the soft tissues of the proximal third of the segment (from level 0 to level III) are “relatively stationary” during movement of the joint, which is distal relative to the given segment. Similarly, the amount of soft-tissue displacement relative to the bone during movements

335

of the joint proximal to the given segment can be neglected from level VI to level IX. Levels IV and V are the “boundary”levels and the data obtained here should be interpreted individually. Displacement of soft tissues is minimal in the projections of positions 4 and 8; and is somewhat greater in the projections of positions 9 and 10. In the projection of these positions there are no great vessels or nerves, so at level VII the reference positions are: VII,3; VII,4; VII,8 and VII,9 (page 106). Reference positions are similarly determined for all segments, which is reﬂected in the atlas discussed in section 1.9. The specific characteristics of the evaluation of soft-tissue displacement of the upper arm and forearm, and the upper and lower leg are discussed below.

3.3 Determination of Positions with Minimum Soft-Tissue Displacement 3.3.1

Femur2

For investigating the displacement of soft tissues due to movements of the hip joint, the basic support is positioned at the level of the distal femur metaphysis (Fig. 3.4), and due to movements of the knee joint, at the level of the proximal femur metaphysis (Fig. 3.5). Because of the particular anatomical characteristics, positions 2, 3 and 4 at levels 0 and I are excluded from examination. In the atlas (section 1.9) reference positions are determined during investigation of soft-tissue displacement as a result of: • Flexion of the hip joint with an amplitude of 90/0. • Hip abduction with an amplitude of 45/0. • Flexion of the lower leg with an amplitude of 90/0.

3.3.2

Upper Arm3

For investigating the displacement of soft tissues due to movements of the shoulder joint, the basic support is positioned at the level of the distal metaphysis of the humerus (Fig. 3.6), and due to movements in the elbow joint, at the level of the proximal metaphysis of the humerus (Fig. 3.7). Because of the particular anatomical characteristics, positions 2, 3 and 4 at levels 0 and I are excluded from examination. In the atlas (section 1.9) reference positions are determined during investigation of soft-tissue displacement as a result of: 2

3

The material presented was prepared in collaboration with M.V. Andrianov. The material presented was prepared in collaboration with R.E. Inyushin.

336

3 Appendix 1: Method for the Definition of “Reference Positions” for the Insertion of Transosseous Elements

VIII,8,90;VIII,4,90;VIII,12,90

I,8,90; I,12,90; II,10,90

Fig. 3.4. Device for investigating soft-tissue displacement as a result of hip flexion and abduction

Fig. 3.5. Device for investigating soft-tissue displacement as a result of flexion of the lower leg

VIII,4,90; VIII,8,90; olecr.,6,90

I,8,90; I,10,90; II,11,90

Fig. 3.6. Device for investigating soft-tissue displacement as a result of flexion and abduction of the arm

Fig. 3.7. Device for investigating soft-tissue displacement as a result of flexion of the forearm

3.3 Determination of Positions with Minimum Soft-Tissue Displacement

337

VII,5,90; VIII,9,90; VIII,12,90

I,3,90; I,12,90; II,8,90

Fig. 3.8. Device for investigating soft-tissue displacement as a result of flexion of the knee joint

Fig. 3.9. Device for investigating soft-tissue displacement as a result of movement of the ankle joint

•

3.3.4

Flexion of the shoulder joint with an amplitude of 65/0. • Arm abduction with an amplitude of 90/0. • Flexion of the forearm with an amplitude of 90/0.

Forearm5

For investigating soft-tissue displacement due to movements of the knee joint, the basic support is positioned at the level of the distal metaphysis of tibia (Fig. 3.8), and due to movements of the ankle joint, at the level of the proximal metaphysis of the tibia (Fig. 3.9). Because the evaluation of soft-tissue displacement relative to the fibula does not have any important clinical significance, in the atlas (section 1.9) reference positions are determined during investigation of soft-tissue displacement relative to the lower leg as a result of: • Flexion in the knee joint with an amplitude of 120/0. • Movements in the ankle joint with an amplitude of 40/0/20.

Experiment features: 1. The displacement of soft tissues relative to the ulna and the displacement relative to the radial bone are investigated separately. 2. The forearm is positioned midway between pronation and supination. 3. The control support is centred in relation to the bone for which measurements are to be made. In the atlas (section 1.9) reference positions are determined during investigation of soft-tissue displacement as a result of: • Flexion in the elbow joint with an amplitude of 140150◦ . • Movements of the wrist joint (amplitude of ﬂexion/extension 110–130◦ and radial/ulnar abduction 50–70◦ ). • Rotational movements with an amplitude of 160◦ (80◦ supination, 80◦ pronation).

4

5

3.3.3

Lower Leg4

The material presented was prepared in collaboration with D.A. Mykalo.

The material presented was prepared in collaboration with P.N. Kulesh.

338

3 Appendix 1: Method for the Definition of “Reference Positions” for the Insertion of Transosseous Elements

Fig. 3.10a,b. Devices for investigating softtissue displacement as a result of movement of the elbow joint relative to the ulna (a) and relative to the radius (b)

VII,3,90; VIII,6,90(VIII,6,90); m.carpi II,12,90 a

b

(VII,3,90); VIII,6,90(VIII,6,90); m.carpi II,12,90 (b)

olecr.,6,120; I,5,90(I,5,90); I,9,90 a

b

(a)

(a)

olecr.,6,120; I,5,90(I,5,90); (II,9,90) (b)

Fig.3.11a,b. Devices for investigating soft-tissue displacement as a result of movement of the wrist joint relative to the ulna (a) and relative to the radius (b)

3.3 Determination of Positions with Minimum Soft-Tissue Displacement

339

Fig. 3.12. Device for investigating soft-tissue displacement as a result of forearm rotation relative to the ulna bone. The distance between lines AA and BB at each level reflects the magnitude of the softtissue displacement at that level as shown, for example, in the projection of position 4

olecr.,6,120; I,5,90; I,8,90

When investigating soft-tissue displacement due to movements of the elbow joint at levels 0, I, II and III, the control support on the ring base will not allow the forearm to be bent by 140–150◦ . Therefore, at these levels a three-quarter support is used. The basic support is fixed on three half-pins (Fig. 3.10). When measuring soft-tissue displacement due to movements of the wrist joint,the basic transosseous elements are inserted at the level of the proximal metaphysis of the forearm bones (Fig. 3.11). To measure soft-tissue displacement due to forearm rotation, the control support is replaced by a long connection plate with a threaded end in which the guides for insertion of the feelers are fixed at the standard levels of the forearm. During the procedure a cantilever is fixed at each of 12 standard positions in turn. When investigating soft-tissue displacement relative to the ulna, the basic transosseous elements are inserted at the level of the proximal metaphysis of the forearm bones. The half-pin olecr.,6,120 is inserted into the distal metaphysis of the humerus, blocking the elbow joint (Fig. 3.12). When investigating soft-tissue displacement relative to the radius due to forearm rotation,the basic transosseous elements are inserted at the level of the distal metaphysis of the radius. To prevent movements of the wrist joint, a half-pin is additionally inserted into the second metacarpal (Fig. 3.13).

(VII,1,90); (VIII,10,90); m/carpi II,12,90 Fig. 3.13. Device for investigating soft-tissue displacement as a result of forearm rotation relative to the radius

340

3 Appendix 1: Method for the Definition of “Reference Positions” for the Insertion of Transosseous Elements

Fig. 3.14. Device for determining the magnitude of skin displacement due to movement in a joint. Two fixing belts (2) with textile fasteners (3) are attached to a platform (1). A riser (4) is rigidly fixed in the centre of the rectangle and perpendicularly to it. To the riser is attached a pivoted telescopic rod (5) to the opposite end of which is fixed with nuts a support (6) (ring, half-ring, or three-quarter ring) with a slide (7). To the slide (7) is fixed a pivoted tube (8) onto one end of which are mounted a light source (incandescent lamp) and a beam-focusing device (9)

The further measurements are carried out in the same way as described for the ulna. To determine skin displacement due to movements of joints in an individual patient the device shown in Fig. 3.14 is used. Its main feature is nonrigid fix-

ation of the basic support onto the segment surface. Instead of the light source (incandescent lamp) and a beam-focusing device (Fig.3.14(9)),one may use a laser pointer or the feelers – as in a standard device (Figs. 3.1 and 3.2).

4 Appendix 2:Method for RigidityTesting of External Fixation Assemblies1

4.1

Introduction

Rigidity is the ability of the elements of a construction to resist displacement. Values for the rigidity of bone fragment fixation are basic values characteristic of devices for external or internal fixation. Testing instruments used in machine building can only to some extent be adapted for determination of the rigidity of osteosynthesis. To determine the rigidity of models in six degrees of freedom, it is necessary to have many testing instruments, which only few investigators can afford. Therefore, some investigators are forced to use nonstandard equipment of their own design. Differences in experimental methods in relation to the choice of material for simulating bone and the way it is destroyed, the way the model is fixed to the bench, the number of displacement indicators and methods for their installation, the methods for evaluation of the test results etc. do not allow data from different authors to be compared. Thus, the absence of a standard method for rigidity testing of external fixation assemblies can be considered an obstacle to determining the optimal construction for a particular application. Clinically, this situation is often seen in the use of external devices that do not provide sufficient osteosynthesis rigidity for effective functional treatment. This enhances the risk of complications and can inﬂuence the results of treatment. Also attempts to increase the rigidity of bone fragment fixation which are not quite sufficient may result in increased surgical trauma and a bulky device. The material presented in this chapter enables deficiencies in preoperational planning to be made up and provides the investigator and practicing physician with a method for the analytical determination of the optimal external device assembly for a specific clinical situation. The method for investigating the rigidity of bone fragment fixation presented here includes an algorithm of standard actions and calculations to determine the basic rigidity characteristics of the external fixation device. The ability to replicate the experiment and to 1

The material presented was prepared in collaboration with P.I. Begun and V.A. Nazarov.

verify the research data is ensured by the use of the “Method for the Unified Designation of External Fixation” and by applying standard displacing forces and standard processing to determine the Ilizarov index.

4.2 Indications and Contraindications From the biomechanical point of view, long bones injuries can be divided into two types: • Type I: Fracture of a single-bone segment or fracture of both bones in a two-bone segment.Fractures of one bone of a two-bone segment due to luxation of the proximal or distal interosseous articulations (radioulnar, intertibial) are classified as type I. • Type II: Fracture of one bone of a two-bone segment with retention of anatomic interrelationships in the proximal and distal interosseous joints.When a previous luxation of a pair bone was set and the possibility of reluxation is eliminated (ligament suturing performed, diafixing wire inserted), then the given injury could also be classified as type II. The method is developed for the experimental determination of fixation rigidity values in models of extrajoint diaphyseal monolocal fractures of type I for any external devices. The method is not intended for examining models of external fixation of intraarticular fractures and injuries of type II.

4.3

General Theoretical Principles

4.3.1 Transosseous Module Classification A functional unit in the construction of external devices is the external support with one or several transosseous elements fixed to it. This functional unit is designated as a transosseous “first-order module” (M1; Fig. 4.1). Two modules of the first order united into a general subsystem (fixing one bone fragment) are designated as a “second-order module” (M2; Fig. 4.2). Third-order modules (M3) for one bone fragment can be considered only in hypothetical terms. Therefore, a

342

4 Appendix 2: Method for Rigidity Testing of External Fixation Assemblies

a

Fig. 4.1a,b. First-order modules. a Modules with transosseous elements of the same type (only wires or only half-pins) are uniform first-order modules (M1u). b Modules with external supports and different types of transosseous elements (e.g. a wire or a half-pin) are combined first-order modules (M1c)

b

a

b

Fig. 4.2a,b. According to established biomechanical requirements, each bone fragment fixed in an external device is fixed with one or two first-order modules. A subsystem comprising two first-order modules (fixing one bone fragment) is designated a second-order module (M2). a A uniform second-order module (M2u) is a subsystem comprising two uniform firstorder modules. b A combined second-order module (M2c) is a subsystem comprising two combined first-order modules or a uniform second-order module together with a combined second-order module

module M3 is the complete arrangement of the external device. When there are two bone fragments, there are three versions of the module M3: M1 + M1 M1 + M2 or M2 + M1 M2 + M2 Depending on the types of transosseous elements being used (only wires, only half-pins, combination of wires and half-pins), modules M3 are formally designated as M3u or M3c. A general classification of external fixation modules is given in Table 4.1. The use of the concept “module” in the given context allows the use of the term in external fixation to be regulated.The given classification of modules ensures a standardized approachto investigating the biomechanics of transosseous osteosynthesis rigidity: in the direction from the most known uniform (wire) first-order modules (M1u) to combined second-order modules (M2c) to the complete external device assembly (module M3).

Table 4.1. Classification of transosseous modules M1 M1u

First-order modules Uniform first-order modules

M1c M2

Combined first-order modules Second-order modules

M2u M2c

Uniform second-order modules Combined second-order modules

M3 M3u

Third-order modules Uniform third-order modules

M3c

Combined third-order modules

4.3.2 Method for the Unified Designation of External Fixation To allow replication and verification of experiment results by any investigator, all assemblies of the external devices should be strictly designated. It is known that changing the levels of insertion of transosseous elements, their angle of intersection, the geometry and dimensions of the external supports, the distance be-

4.3 General Theoretical Principles

a

343

b

Fig. 4.3a,b. Schematics of standard displacing loads. a Possible displacements according to degrees of freedom, b Loading scheme). F1 longitudinal distraction/compression force, F2 transverse abduction/adduction force, F3 transverse flexion/extension force, F4 rotational inward/outward force, A frontal plane, B transverse (horizontal) plane, C sagittal plane

tween the supports and the biomechanically preset condition between them, and also other values, inﬂuences the experiment results. Therefore, an obligatory condition for investigating the rigidity of transosseous osteosynthesis is the exact designation of assemblies of the examined devices with the help of the “Method for the Unified Designation of External Fixation”. Section 1.8 gives a full description of the method.

4.3.3

Modelling the Displacing Forces

When investigating the rigidity of osteosynthesis, the response of the transosseous modules to displacing loads in six standard degrees of freedom is examined (Fig. 4.3a). The rigidity of a transosseous module is represented by its ability to resist the displacement of fragments caused by the inﬂuence of an external load. The rigidity of osteosynthesis is characterized by: • Rigidity coefficient (K), which is determined from the ratio of the external loads to the linear and angular displacements. • Compliance, which is determined from the ratio of the linear and angular displacements to the isolated loads (of opposite magnitude to the rigidity coefficient). This method uses the first of the above characteristics. The greater the rigidity coefficient, the greater the rigidity of the bone fragment fixation.

Axial forces F1 , compression and distraction, are applied in the direction of the longitudinal axis of the model bone. The rigidity of osteosynthesis in longitudinal distraction is the rigidity of external fixation under the inﬂuence of an extension force F1 in the longitudinal direction. The rigidity of osteosynthesis in longitudinal compression is the rigidity of osteosynthesis under the inﬂuence of a compression force F1 in the longitudinal direction. Transverse forces F2 during abduction and adduction cause angular displacements of the fragment in the frontal plane A (Fig. 4.3). The rigidity of osteosynthesis in abduction is the transverse rigidity of osteosynthesis during ﬂexion of the fragment by a force F2 in the frontal plane. The rigidity of osteosynthesis adduction is the transverse rigidity of osteosynthesis during ﬂexion of the fragment by a force F2 in the frontal plane. Transverse forces F3 cause angular displacements of the fragment in the sagittal plane C (Fig. 4.3). Flexion rigidity of osteosynthesis is the transverse rigidity of osteosynthesis during ﬂexion of the fragment by a force F3 in the sagittal plane. Extension rigidity of osteosynthesis is the transverse rigidity of osteosynthesis during ﬂexion of the fragment by a force F3 in the sagittal plane. Rotational forces F4 cause angular displacements of the fragment in the transverse plane B (Fig. 4.3). Outward rotation of osteosynthesis is the rigidity of osteosynthesis during rotation of the fragment by a force F4 in the transverse plane. Inward rotation rigidity of

344

4 Appendix 2: Method for Rigidity Testing of External Fixation Assemblies

Fig. 4.4. The standard first-order module (M1st) is considered a model based on a ring support from the complete set of the Ilizarov apparatus with an inner diameter of 160 mm. The long axis of the bone model is located in the centre of the ring support. The diameter of the wires is 2 mm, their angle of separation is 60◦ , and their tensioning force is 1000 N. The bone model is 175 mm long. The wires are inserted at a distance of 25 mm from the base of the bone model, which is assumed to be at level I. The length of loading arm in the sagittal and frontal planes (L) is 100 mm I,2-8; I,4-10 160

Fig. 4.5. The standard second-order module (M2st) is considered a model based on two ring supports 150 mm apart and connected with three rods. The bone model is 280 mm long. The wires of the proximal support are inserted at a distance of 25 mm from the base of the bone model, which is assumed to be at level I. The distance between the levels is assumed to be 50 mm. The wire with a stop of the second support is inserted at the level IV at a distance of 150 mm from level I. The tensioning force of the wires is 1000 N. The length of the loading arm in the sagittal and frontal planes (L) is 250 mm I,2-8; I,4-10 —— IV,3-9 160 160 Fig. 4.6. The standard third-order module (M3st) is considered a complete external device, consisting of two standard second-order modules connected by three rods. The bone simulator is 500 mm long. The wires of the proximal support are inserted at a distance of 50 mm from the base of the bone simulator; which is assumed to be at level I. The distance between the levels is assumed to be 50 mm. A diastasis of 2 mm is made between the bone fragments in order to investigate the response of the model to an axial compression load. The length of the loading arm in the sagittal and frontal planes (L) is 275 mm I,2-8; I,4-10 —— IV,3-9 —— V,9-3 —— VIII,2-8; VIII,4-10 160 160 160 160

osteosynthesis is the rigidity of osteosynthesis during rotation of the fragment by a force F4 in the transverse plane. Linear rigidities of the module are characterized by the rigidity coefficients of distraction and compression K: K = F1 /U where U is the fragment displacement in the axial direction due to distraction or compression. The unit for measuring the linear rigidity coefficient is Newtons per millimetre (N/mm). Transverse rigidities of osteosynthesis are characterized by rigidity coefficients K: K = F2 L/ where L is the length of the arm on which the transverse forces create bending moments (distance from the point of application of the force to the site of rigid

fixation of the module, Fig. 4.3), and is the angle of fragment rotation under the inﬂuence of the transverse forces, during abduction, adduction, ﬂexion or extension. In module M1st, LM1st = 100 mm (Fig. 4.4); in module M2st, LM2st = 250 mm (Fig. 4.5); in module M3st, LM3st = 275 mm (Fig.4.6).The unit for measuring transverse rigidity coefficients is Newton millimetres per degree (N mm/degree). Rotational rigidities of osteosynthesis are characterized by rigidity coefficients K of osteosynthesis during inward and outward rotation: K = F4 h/ where h is twice the distance from the point of application of force F4 to the fragment axis (Fig. 4.3, and is the angle of fragment rotation under the action of rotational forces, inwards or outwards. For all modules (M1, M2, M3) h = 200 mm.

4.4 Experimental Procedures

345

Table 4.2. Rigidity coefficients of standard modules Rotational rigidity Module

KM (N mm/degree) Inward 3

Outward 3

Transverse rigidity

Longitudinal rigidity

KM (N mm/degree) Sagittal plane Flexion 2

KM (N/mm)

Frontal plane

Extension 2

Adduction 2

Abduction 2

Distraction

Compression

First-order M1st

3×10

3×10

3×10

3×10

7×10

7×10

63

63

Second-order M2st

3.2×103

3.2×103

2×103

2×103

3.51×103

3.51×103

54

54

Third-order M3st

2.8×103

2.8×103

2.03×103

2.03×103

6.6×103

6.6×103

53

53

It should be noted that the purpose of the experiment is not to determine the displacing force which will destroy or deform the transosseous elements and the device frame,because such knowledge is of no great importance for clinical practice. The experiment is carried out on the basis that, when the displacement of the loaded fragment (when investigating first- and secondorder modules) or the displacement at the junction of bone fragments (when investigating third-order modules) has reached 1 mm or 1◦ , further loading is not advisable (it would serve no purpose).

elling the displacing forces,the deformation of the bone model is infinitesimal compared with the deformation of the transosseous elements. The use of cadaver bones for the bench tests also has no obvious advantages; but has limitations of a legal and ethical nature. There is also the practical difficulty of obtaining cadaver bones with similar anthropometric properties suitable for the experiment. Therefore, wooden rods with a diameter of 30 mm are used in the investigations as bone models.

4.3.4 Primary Standard for Rigidity of Transosseous Modules

4.4

To compare the rigidity of modules of different devices, it is necessary to use a primary standard. When comparing a module with the standard module, the relative rigidity (Ilizarov rigidity index, Il) is determined: Il = Kst /Kex where Kst is the rigidity coefficient of the standard module,and Kex is the rigidity coefficient of the module under examination. Thus, to determine the Ilizarov index it is necessary to know the values of Kst for M1st, M2st, M3st in the presence of compression, distraction, ﬂexion, extension, adduction, abduction, inward rotation and outward rotation. Table 4.2 shows rigidity coefficients of standard modules. For example: • When Il = 1, the rigidity of the examined module equals that of the standard module. • When Il = 0.5, the rigidity of the examined module is twice that of the standard module. • When Il = 2, the rigidity of the examined module is half that of the standard module. The use of wood, metal or plastic for simulating bone may be considered a problem in principle, but is not a problem in practice because, in the process of mod-

Experimental Procedures

The experiment is repeated three times in each case and the results are analysed statistically using a software program package, e.g. Statgraphics.

4.4.1 Investigating Rigidity of the Transosseous Modules of the First (M1) and Second (M2) Order An algorithm for investigating the rigidity of first- and second-order modules is presented, by way of example, for investigating a standard first-order module (M1st; Fig. 4.4).

4.4.1.1 Longitudinal Rigidity A diagram of the experiment is shown in Fig. 4.7. The force that causes a displacement of 1 mm is considered the control force. When loading most assemblies in the range 5–200 N, the load–displacement curve can be approximated with sufficient accuracy by straight-line segments with load increments of 5 N. The relationship between displacement and force is assumed to be linear with these increments. When investigating assemblies, to ensure adequate rigidity values for the osteosynthesis, the load increment can be decreased.

346

4 Appendix 2: Method for Rigidity Testing of External Fixation Assemblies

a

b

Fig. 4.7a,b. Investigation of the longitudinal rigidity of a first-order module in compression (a) and distraction (b). The external support of the module is rigidly fixed. An instrument to measure the linear displacement is attached to the base of the bone simulator. The studied load (e.g. distraction) is applied gradually increasing in increments 5 N. The displacements of the bone simulator with each load increment are recorded. The experiment is stopped as soon as the displacement reaches 1 mm

Fig. 4.8. Schematic modelling rotational loads. The external support of the module is rigidly fixed. On the free end of the loaded bone simulator fragment a metal bar (1) is mounted. To points A and B, which are at the same distance from the centre of the bone simulator, two sensing instruments are attached at a recommended distance apart (L) of 100 mm. The load is applied at points A1 and B1 on a second metal bar, which is also mounted on the free end of the loaded bone simulator fragment at a distance of 50 mm from the support plane (for a second-order module at a distance of 50 mm from the distal support). Points A1 and B1 are also equidistant from the centre of the bone simulator. The recommended distance between points A1 and B1 (h) is 200 mm

Investigation of standard first-order modules has shown that a displacement of 1 mm occurs with a load

The rotational angle of the bone model is calculated from the equation:

of 63±5 N. Thus, the rigidity coefficient of the module under the inﬂuence of a distraction force is:

tg'i = (|VAi | + |VBi |)/L,

KM1st/distraction = 63 N/mm

where L is the distance between points A and B. The force that causes outward or inward displacement of the bone model (depending on the direction of the rotational load) ' 1◦ is considered the control force. Investigation of M1st has shown that displacement of 1◦ occurs with an inward or outward load (F4) of 15±1 N. Thus, the rigidity coefficient of a standard first-order module under the inﬂuence of an inward or outward rotational force is:

The particular characteristics of the N1st (insertion of two wires without stops in one plane perpendicular to the long axis of the bone model) ensure the same value of the rigidity index for distraction and compression: KM1st/compression = 63 N/mm 4.4.1.2 Rotational Rigidity A diagram of the experiment is shown in Fig. 4.8. The load F4 is applied inwards or outwards gradually increasing in increments of 2 N. Displacement values VA and VB at points A and B obtained from displacement sensing instruments after each load increment (VAi andVBi ,where i is the number of the applied load) are used for further processing.

KM1st/inward = KM1st/outward = 15 × 200 = 3 × 103 N mm/degree 4.4.1.3 Transverse Rigidity A diagram of the experiment, modelling ﬂexion and extension, is shown in Fig. 4.9.

4.4 Experimental Procedures

Fig. 4.9. Investigation of the transverse rigidity of the standard first-order module in the sagittal plane under flexion. To apply the flexion load in the sagittal plane (for the standard first-order module – in wires intersection sector of 120◦) two linear displacement sensing instruments of the clock type are attached to the free end of the bone simulator at a distance apart (a) of 40 mm. The distance from the plane of the ring support (point O) to the first indicator (b) is 40 mm. In a second-order module, point O is in the plane of the distal support. To apply an extension load in the sagittal plane, the assembly is rotated by 180◦ and fixed

Displacements of the bone model (V) at points A and B following each load increment (VAi and VBi , where i is the number of the applied load) are measured using displacement sensing instruments. The rotational angle of the bone model following each load increment is determine from the equation: tg'i = |VAi − VBi |/a = n, where a is the distance between points A and B. A load is applied in the sagittal plane (relative to the orientation of M1 and M2) gradually increasing in increments of 1 N. The load is applied at a distance of 100 mm from the conventional point O. For ﬂexion and extension resulting from the application of force F3 , the load that leads to rotational displacement of the bone model by ' 1◦ is considered the control force. For M1st it has been established that a displacement of 1◦ in the sagittal plane due to ﬂexion and extension occurs with a load of 3±0.5 N. Thus, the rigidity coefficient of a standard first-order module under ﬂexion or extension is: KM1st/ﬂexion = KM1st/extension = 3 × 100 = 3 × 102 N mm/degree

347

Fig. 4.10. Investigation of the transverse rigidity of a firstorder module in the frontal plane (for the standard firstorder module – in wires intersection sector of 60◦ ). The experiment is similar to that for module load in the sagittal plane (Fig. 4.9) with the difference that abduction and adduction are modelled

The arrangement of sensing instruments in the plane of application of the forces, the values of the forces F2adduction , F2abduction , and the calculations are similar to those discussed for investigations in the sagittal plane. For M1st it has been established that displacement of 1◦ in the frontal plane for abduction and adduction occurs with a load (F2) of 7 ± 0.5 N. Thus, the rigidity coefficient of a standard first-order module in the frontal plane is: KM1st/abduction = KM1st/adduction = 7 × 100 = 7 × 102 N mm/degree For investigation (when necessary) of a module in any other intermediate transverse plane the model is fixed to the fixing panel of the bench in a position that ensures loading in the plane under investigation.

4.4.2 Investigating the Rigidity of ThirdOrder Modules (M3) Diagrams of the experiment for investigating longitudinal rigidity are shown in Fig. 4.11. The load leading to displacement of the bone model by 1 mm is considered the control load. For standard third-order modules it has been established that displacement of 1 mm occurs with a load of 55±5 N. Thus, rigidity coefficient of a third-order module is: KM3st/distraction = KM3st/compression = 55 N/mm

4.4.1.4 Transverse Rigidity in the Frontal Plane when Modelling Abduction and Adduction

4.4.2.1 Rotational Rigidity

A diagram of the experiment is shown in Fig. 4.10.

A diagram of the experiment is shown in Fig. 4.12.

348

4 Appendix 2: Method for Rigidity Testing of External Fixation Assemblies

a

b Fig. 4.11a,b. Investigation of the longitudinal rigidity of a third-order module (a compression, b distraction). The free proximal end of the fragment is rigidly fixed. A linear displacement measuring instrument is attached to the base of the loaded fragment. The load (e.g. distraction) is applied gradually increasing in increments of 5 N. The displacements of the bone simulator with each load increment are recorded. The experiment is stopped as soon as a displacement of 1 mm has been reached

A load is applied gradually increasing in increments of 2 N. Displacement (V) at points A and B following each load increment (VAi andVBi ,where i is the number of the applied load) are measured using displacement sensing instruments. The rotational angle of the bone model is calculated from the equation:

applied load) are measured using displacement sensing instruments. To apply the load for extension, the assembly is fixed after turning through 180◦ . The rotational angle of the bone model is determined following each load increment from the equation: tg'i = (|VAi | + |VBi |)/L,

tg'i = (|VAi | + |VBi|)/L,

where L is the distance between points A and B. The force that causes displacement of the bone model by 1◦ is considered the control force. For thirdorder modules it has been established that a displacement of 1◦ in the sagittal plane during ﬂexion and extension occurs with a load of 11±0.1 N. Thus, the rigidity coefficients of a standard third-order module in the sagittal plane during ﬂexion and extension are:

where L is the distance between points A and B. For standard third-degree modules it has been established that a displacement of 1◦ occurs with a load of 14 ± 1 N. Thus, the rigidity coefficients of a standard third-order module for inward or outward rotation are: KM3st/inward = KM3st/outward = 14 × 200 = 2.8 × 103 N mm/degree

KM3st/ﬂexion = KM3st/extension = 11 × 275 = 3.02 × 103 N mm/degree

4.4.2.2 Transverse Rigidity A diagram of the experiment modelling ﬂexion and extension in the sagittal plane is shown in Fig. 4.13. A load is applied gradually increasing in increments of 1 N.The load is applied at a distance 100 mm from the conventional point O, located in the plane of level VIII. Displacement (V) at points A and B following each load increment (VAi and VBi , where i is the number of the

4.4.2.3 Transverse Rigidity in the Frontal Plane when Modelling Abduction and Adduction A diagram of the experiment is shown in Fig. 4.14. The arrangement of the sensing instruments in the plane of application of the forces, the applied loads F2 , and the calculations are similar to those for investigating rigidity in the sagittal plane.

4.4 Experimental Procedures

349

Fig. 4.12. Investigation of the rotational rigidity of a third-order module. The free proximal end of the fragment (2) is rigidly fixed. A metal bar (1) is mounted on the loaded end of the bone simulator. Two sensing instruments are attached to points A and B, which are located at the same distance from the centre of the bone simulator at a recommended distance apart (L) of 100 mm. The load is applied to points A1 and B1 on a second metal bar which is also mounted at the loaded end of the bone simulator at a distance of 50 mm from the plane of the distal support. Points A1 and B1 are also equidistant from the centre of the bone simulator and are at a recommended distance apart (h) of 200 mm

Fig. 4.13. Investigation of the transverse rigidity of a third-order standard module in the sagittal plane during flexion and extension (for the standard third-order module - in wires intersection sector of 120◦ of the basic supports of thirdorder module). To apply the load in the sagittal plane during flexion two linear displacement measuring instruments are attached to the distal end of the bone simulator at a distance apart (a) of 40 mm. The distance from the point O (point O is at level VIII) to the first sensing instrument (b) is 40 mm

Fig. 4.14. Investigation of the transverse rigidity of a third-order module in the frontal plane (for a third-order module with an angle opening of the basic supports for the standard third-order module in the sector of the basic supports wires intersection of 120◦). The algorithm for performing the experiment is similar to that for the module loading in the sagittal plane (Fig. 4.13)

For standard third-order modules it has been established that a displacement of 1◦ in the frontal plane due to abduction or adduction occurs with a load of 24 ± 0.1 N. Thus, the rigidity coefficients of a standard third-order module in the frontal plane during abduction or adduction are: KM3st/abduction = KM3st/adduction = 24 × 275 = 6.6 × 103 N mm/degree

For investigation of a module in any other intermediate transverse plane the model is fixed to the fixing panel of the bench in a position that ensures loading in the plane under investigation. Experimental rigidity coefficients for all standard modules are presented in Table 4.2. These data not only allow the Ilizarov index to be obtained but also serve as criteria for establishing the correctness of manufacture of the biomechanical bench and of the conduct of the investigation.

Index

Accordion method 230 Achilles tendon 186, 190, 282, 299, 300 Aesthetic deformities 218–220, 222 – correction 218 – false 220 – true 220 Aesthetic surgery 204, 218, 228 Ankle 5, 13, 114–117, 128, 172, 183, 184–190, 192, 201, 202, 220, 228, 245, 275, 277, 278, 280, 282, 291, 298–301, 306, 307, 310, 320, 335, 337 Apex of deformation (see also Fulcrum, Centre of rotation of angulation (CORA)) 204, 207, 208 Apparatus (see also Assemblies, Devices, External supports, Modules) 6, 12, 23, 24, 27, 117, 118, 262–264, 266, 268, 273, 302, 324 – Barabash 3, 165, 197, 255 – Biomet 3, 4 – Demianov 1, 2, 4, 160, 161 – Gudushauri 1, 2, 4 – Hoffman-Vidal 2, 4 – Ilizarov 5, 6, 25, 202, 209, 306, 307, 344 – Kalnberz 1, 2, 4, 33 – Lambotte 1, 2, 4 – Lee 3, 4, 277, 278 – Malgaigne fixator 1 – OrthoFix 3, 4 – Poli Hex 3, 4, 15, 209 – Sivash 1, 4 – Stryker 3 – SUV-frame 3, 4, 15, 25, 209 – Synthes 3 – Taylor spatial frame 3, 4, 15, 37 – Tkachenko 1, 2, 4 – Volkov-Oganesyan 1, 2, 4 Arthrodesis 6, 118, 121, 121, 188, 277, 278, 283, 284, 285, 287–292, 298, 300, 301, 303, 308, 319 – ankle 298, 300, 301 – calcaneocuboid 301 – compression 118, 283, 284, 297, 291, 292, 298, 300, 303, 308 – elbow 285, 287 – hip 289, 291, 292 – humeral joint 283 – knee 298 – lengthening 298 – Lisfranc joint 274, 276, 277 – panarthrodesis of the foot 301

– subtalar joint 301 – taloscaphoid 301 – wrist 288, 289 Arthrolysis 296, 297, 324 Arthroscopic monitoring 171, 175, 176, 184 Arthroscopic release 296, 297, 299 Assemblies (see also Apparatus, Devices, External supports, Modules) 9, 18, 27, 158, 163, 184, 202, 207, 228, 230, 270, 307, 341–347 – components see under Modules – external devices 34, 118, 119, 204, 209, 260, 308, 309, 319, 322, 324, 341, 342, 344 – external supports 1, 4, 7, 13, 15, 20, 22, 23, 25, 26, 28, 34, 118–122, 124, 129, 130, 131, 133, 139, 141, 142, 145–147, 150, 151, 153, 154, 156, 158, 159, 161, 164, 165, 172–174, 183, 192, 194, 195, 198, 207, 209, 211, 232, 234, 237, 244, 247, 252, 253–255, 260, 264, 271, 283–285, 292, 294, 303, 304, 308, 309, 319, 320, 322, 323 Atlas for Insertion of Transosseous Element “Reference Positions” (see also Method for the Unified Designation of External Fixation (MUDEF)) 35–116, 155, 288, 293 – contraindicated positions 35, 38, 41–48, 50–73, 75–98, 100–107, 109–116, 333 – reference positions 13, 35–116, 118, 119, 130, 141, 144, 158, 173, 192, 251, 256, 285, 288, 293, 298, 302, 304, 322, 323, 333–338, 340 – safe positions 35, 38, 40–112, 114–116, 118, 119, 121, 131, 132, 139, 142, 146, 149, 151, 155, 159, 164, 174, 192, 298, 302, 333 Bandage 191, 194, 250, 253 – cravat 153, 155, 158, 254, 269 – plaster 250, 320, 321 – sling 194 Barabash cube 10, 165 Biomechanical principles 12 Biomechanics 10, 12, 23, 26, 38, 119, 124, 165, 251, 284, 293, 307, 321 – bone-metal block 12, 22, 256 – displacing forces 22, 23, 252, 341, 343–345 Bolts 122, 123, 128, 131, 179, 181, 198, 334 Bone fragments (see also Repositioning) 13–15, 17, 19, 20–28, 35, 36, 38, 49, 117–119, 122–124, 129–136, 138–143, 146–168, 171, 173, 174, 179–181, 184, 192, 194, 198, 201, 202, 204, 207, 209, 210, 213, 215, 228,

352

Index

229, 231, 232, 233, 236, 237, 241–246, 248, 249, 251, 253–256, 260, 269, 275, 277, 283, 287, 288, 291, 297, 302, 304, 307–309, 319, 323–326, 341–345 – displacement 38, 117, 129, 198, 213, 256, 308 – distal 124, 131, 133, 134, 136, 138, 140, 146, 147, 150–153, 155, 158, 164, 165, 168, 179, 181, 192, 194, 201, 204, 210, 319 – “icicle-shaped” form 194 – intermediate 194, 198 – proximal 132, 134–136, 138–140, 146–148, 151–153, 162–165, 167, 168, 179, 181, 308 – reduction 10, 25, 27, 124, 180, 201, 302, 305, 325 – relocation 173, 179, 181, 194, 195, 232, 233 – rigidity 5, 12, 15, 20, 22–26, 119, 120, 122, 124, 143, 175, 176, 181, 183, 302, 304, 305, 307, 324, 325, 341–343 – spatial orientation 20, 23, 28, 49, 121, 129, 130, 141, 159, 173, 243, 244, 304, 323 Bone transport (see also Defects, Intermediate fragment relocation) 36, 194, 195, 302, 303, 308, 309, 321 – cross-wire 194, 309, 321 – oblique-wire 308, 321 – Weber’s technique 195 Bone-metal block 12, 22, 256 Calcaneus 274, 275, 277–282 Carpals 49, 56, 57, 69–74, 78–82, 87–90, 142, 156, 158, 288, 339 Centre of rotation of angulation (CORA) (see also Apex of deformation) 204, 208, 213, 279 Classification 1, 26, 269, 341, 341 – AO/ASIF (fractures) 4, 5, 118, 129, 158, 162, 164, 165, 168, 169, 172, 175, 176, 178, 179, 183, 184, 190, 241, 243, 245, 251, 253, 260, 262 – Kaplan-Markova (open fractures) 191 Clavicle 5, 27, 125, 251–255 Clinical testing 271, 273, 310, 319 Clubfoot see Talipes Combined external fixation (CEF) 23, 25–27, 129, 132, 133, 135, 137, 138–141, 148, 151, 151, 152, 154, 155, 157, 158, 160, 163, 165–167, 170, 172, 173, 177, 178, 180–182, 187, 205, 214, 221, 223, 229, 236, 237, 244, 286, 294, 309, 311, 311, 315 Combined strained fixation (CSF) 6, 236–255, 310, 311, 319 Complications (see also Dermatitis, Inﬂammation of soft tissues, Necrosis) 12, 28, 34, 38, 118, 143, 191, 219, 227, 228, 233, 276, 278, 299, 301–304, 306, 320–326, 341 – infectious (see also Osteomyelitis, Pin-tract infection) 12, 28, 34, 38, 118, 136, 143, 191, 194, 219, 227, 228, 233, 254, 276, 278, 293, 296, 299, 301, 302, 304, 306, 320–326 Compression 1, 14, 22, 26, 34, 36, 118, 146, 147, 151–157, 160, 161, 171, 172, 186, 191–194, 196, 198, 214, 228–233, 236–255, 262, 264, 266, 271, 272, 274, 275, 279, 283–285, 287, 291, 292, 297–301, 303, 304, 307, 308, 319, 322, 323, 327, 343–348 – axial interfragmentary 147

– “microcompression” 230 – rate 285, 308 Computer navigation 15, 25–27, 207 Contracture (see also Polylocal myofasciodeses) 5, 6, 13, 38, 118, 129, 198, 201, 214, 309, 321, 323, 324, 327 – ankle joint 201 – elbow joint 130, 149, 285 – shoulder joint 129 – transfixion 13 – wrist joint 288 Coordinates 28, 337 Corticotomy 194, 201, 202, 204, 209, 221, 223, 231, 234, 297, 299, 301, 302, 308, 321 Coxa vara 315 CRM (see also Image intensifier) 289 Curvature 21, 121, 124, 204, 207, 218, 219, 220, 222, 238, 287 – false curvature 220, 222 – X-shaped 220, 221 Debridement 191, 192, 194, 302 Defects (see also Bone transport) 5, 6, 27, 36, 196–198, 203, 220, 222, 228–235, 237, 241, 242, 246, 248, 251–253, 290, 302, 303, 307 – defect-diastasis 230–232 – defect-pseudoarthrosis 228–235 Deformities 1, 5, 6, 15, 38, 130, 140, 158, 192, 198, 201–209, 211, 213, 215, 217, 218, 221, 228, 230, 237, 244, 246, 251, 266, 269–275, 277–283, 293, 296, 297, 303, 306, 308, 309 – recurvation valgus deformity 220 – torsion 18 – transverse 16, 17, 201 Delayed union 5 Dermatitis 321, 323 Devices (see also Apparatus, Assemblies, External supports, Modules) 19, 21–30, 34, 36, 37, 117–119, 121, 122, 124, 229–232, 234, 236–238, 240, 241, 244–248, 250, 252, 253, 258, 260–262, 264–271, 273–275, 277–280, 283–296, 298–301, 303–310, 319–326, 333, 336–345 Dislocation fractures 131, 133 – chronic dislocation of the head of the radial bone 231 – Lisfranc joint 274, 276, 277 Displacement 13, 15–17, 19–21, 27, 35, 38, 40–73, 75–80, 82–107, 109–119, 121, 129, 136, 138–143, 146–155, 158–160, 162, 164, 165, 168, 169, 171–176, 179, 181, 183, 185, 186, 188, 190, 192, 198, 201, 202, 206, 208–210, 213, 215, 221, 222, 224, 228–230, 244, 247, 251, 256, 260, 262, 263, 265, 266, 268, 270–274, 278, 301, 304, 308, 309, 321–325, 333–335, 336–349 – angular 143, 146, 149, 151, 201, 208, 221, 222, 229, 343 – residual 130, 131, 134–136, 139, 141, 142, 146, 148, 151–153, 155, 164, 165, 168, 169, 175, 179, 181, 183, 185, 188, 190, 198, 201 – rotational 131, 151, 152, 153, 162, 164, 165, 168, 174, 269–272 – soft-tissue 13, 21, 38, 40, 42–116, 120, 170, 177, 256, 289, 304, 323, 333–340

Index

– splinter 191, 201, 224 – transverse 16, 17, 19, 201 Displacing forces (see also Biomechanics) 22, 23, 252, 341, 343, 345 – anatomic axes of fragments are disposed parallel 202 – modelling 343–345 – standard 341, 343 Dissection 273 – acute 273 Distraction (see also Skeletal traction, Traction) 1, 6, 14, 15, 26, 34, 117, 118, 124, 131, 136, 138, 139, 141, 142, 145–148, 150–153, 155–158, 160, 164, 165, 168, 169, 171, 174, 175–177, 179, 181, 183, 184–186, 188, 190, 192–194, 196, 198, 201, 202, 205, 207, 209, 212, 214, 221,223, 224, 227–234, 236, 241, 242, 244, 247, 255, 271 – “microdistraction” 230, 297 Dressings 305, 306, 309, 320–323 – bandages 153, 155, 158, 191, 194, 250, 253, 254, 269, 320, 321 – slings 117, 141, 145, 150, 153, 158, 194, 253, 306 Dynamization 167, 309, 319 Elongation (see also Lengthening) 130, 141, 167, 173, 194, 197, 198, 204, 219, 221, 225–228, 231, 232, 234 Exercise therapy 117, 298, 300, 306, 307, 309, 323 External fixation (see also Osteosynthesis, Transosseous elements) 6, 15, 16, 18, 20, 22–29, 38, 74, 117–119, 121, 129, 131–162, 164–166, 168–176, 178–202, 204, 206–210, 212, 214, 216, 217, 218, 220, 220, 222, 224, 225–234, 236–238, 240, 242, 244, 246, 248–254, 256, 258, 260–280, 282–286, 288–294, 296–304, 306–310, 319–322, 325, 333, 341–343 – combined see Combined external fixation (CEF) – strained see Combined strained fixation (CSF) External supports (see also Assemblies, Devices, Modules) – 1, 4, 7, 13, 15, 20, 22, 23, 25, 26, 28, 34, 118–122, 124, 129, 130, 131, 133, 139, 141, 142, 145–147, 150, 151, 153, 154, 156, 158, 159, 161, 164, 165, 172–174, 183, 192, 194, 195, 198, 207, 209, 211, 232, 234, 237, 244, 247, 252, 253–255, 260, 264, 271, 283–285, 292, 294, 303, 304, 308, 309, 319, 320, 322, 323 Extracortical bone clamp 10 False joints (see also Pseudoarthrosis, Nonunion) 228–235, 241, 242, 245–249, 252–254, 269, 273 Femur 5, 21, 27, 29, 30, 99–107, 158–171, 174–177, 191–194, 196, 201–204, 207, 209–211, 214, 220, 226–228, 230, 232, 234, 236, 237, 239, 243, 244, 254, 255, 267, 269, 289, 291–299, 304, 306, 308, 309, 315, 320, 333–335, 349 Fibula (see also Tibia) 6, 21, 27, 29, 33, 34, 36, 107, 118, 172–190, 192, 199, 204, 220–222, 224, 232, 234, 235, 242, 248, 300, 301, 303, 337 – tibialization 6, 232, 235, 303 Fixation see External fixation – combinative 26, 249–251 – fixator 1, 4–6, 8, 26, 28, 122, 173, 239, 240, 253, 254, 274–277, 280–282, 306

353

– large splinters 131, 133, 139, 142, 146, 151, 152, 155, 159, 160, 166, 175, 179, 181, 182, 191 Foot 5, 6, 13, 117, 118, 161, 168, 172, 174, 183–190, 201, 226, 274–283, 298–301, 306–308, 320, 321 – abductus 282 – adductus 282 – calcaneus 2745, 275, 277–282 – excavatus 282 – planus 282 – supinatus 282 – talipes see Talipes – forefoot 274, 278, 280–282 – hindfoot 274, 277, 278, 281, 282 – midfoot 274, 275, 277, 282 Forearm (see also Radius, Ulna) 5, 10, 21, 26, 29, 31–35, 49, 52–57, 60–65, 68–74, 81, 89, 90, 97, 98, 130, 141–157, 190, 192, 194, 200, 209, 217, 228, 231, 234, 237, 240, 241, 246–251, 253, 254, 285–288, 290, 302, 305, 306, 309, 311, 319, 320, 335–339, 349 Fork device 10, 159, 173 Fractures – calcaneal 277, 278 – classification of 129 – clavicle 251–253 – compound 190–197, 274–276 – cuboid 275, 277 – cuneiform 275, 277 – femoral condyle 169 – femoral neck 160 – femur 5, 158–171, 190, 243, 254, 296, 290 – fibula 5, 172–190 – humerus 129–140, 200, 241, 246, 254, 310, 320 – infected 153, 274 – intraarticular 5, 119, 129, 131, 133, 134, 139, 141, 143, 157, 158, 168, 172, 175, 184, 296, 297, 299, 341 – juxtaarticular 129, 131, 141, 143, 144, 156, 158, 172 – malunited 198, 199, 209, 214, 230, 297, 302, 308, 311 – metatarsal 274–276 – navicula 275, 277 – oblique 146, 147, 151, 153, 154, 171, 241, 246, 251 – oblique-transverse 146, 147, 151–154, 171, 229, 243, 245, 246, 251 – olecranon 1, 144, 145 – open 141, 190, 231, 233, 296, 302 – patella 1, 171, 172 – pelvis 5, 256–273 – phalangeal 274–276 – radius 143, 246–249, 320 – spiral 146, 147, 151–153, 251 – subtrochanteric 160, 162, 243 – talus 277–279 – ulna 142, 144, 145–156, 246, 311, 320 Fragments see Bone fragments Fulcrum 204 Fusion (see also Arthrodesis) 277, 280 Galeazzi 246, 249, 153 Half-pin 4, 6, 8, 9, 10, 12–15, 18–28, 33–35, 38, 49, 74, 119, 121–124, 129–133, 135, 137, 138, 140–142, 148,

354

Index

150, 154, 157–159, 161, 163, 165, 167–173, 177, 178, 180, 182–184, 186, 194, 195, 198, 200–202, 207, 209, 216, 222, 231, 232, 234, 235, 242, 244–247, 249, 253, 256–262, 264–271, 273, 275, 277–279, 281–285, 289, 291–293, 296, 302–304, 320–322, 325 Hinges 12, 17, 34, 124, 141, 145, 169, 171, 175, 176, 192, 201, 207, 209, 211–213, 221, 222, 228, 230, 240, 279, 281, 287, 289, 294, 296, 297, 299, 300, 302, 309 Humerus 5, 21, 29, 30, 36, 40, 43, 44, 124, 129–139, 193, 194, 200, 209–217, 226, 228, 229, 234, 237, 239, 241–243, 246, 254, 255, 283–285, 287, 304–306, 310, 319, 320, 335, 339 Hypercorrection 130, 141, 158, 166, 168, 169, 173, 175, 201, 224, 228, 271, 289 Ilizarov 1, 5, 129 – apparatus 5, 6, 25, 202, 209, 306, 307, 344 – device 25, 36, 119, 129, 221, 223, 252, 253, 286, 291, 294, 301 – external fixation 25, 131–141, 145, 146, 148, 151–154, 158–162, 164–166, 168–170, 175, 176, 178, 179, 181, 183, 184, 187, 274, 279, 289, 298, 306, 320 – hinges 17, 124, 201 – method 129, 151, 209, 231, 297 – minidevice 171, 288 Image intensifier (see also CRM) 132, 134–136, 139, 146–148, 152, 153, 155, 160, 164, 165, 168, 169, 171, 174, 175, 179, 181, 183, 184, 297 Infection see Arthrolysis, Complications, Inﬂammation of soft tissues, Myolysis, Necrosis, Osteomyelitis, Pin-tract infection Inﬂammation of soft tissues (see also Pin-tract infection) 13, 302, 303, 231–232 Insertion of transosseous elements (see also Atlas for Insertion of Transosseous Element “Reference Positions”, Transosseous elements) 1, 13, 25, 29, 35–116, 121, 122, 130, 141, 155, 158, 160, 172, 192, 232, 251, 256, 285, 288, 293, 302–304, 322, 325, 333–342 Intermediate fragment relocation (see also Defects, Bone transport) 17, 148, 152, 155, 167, 182, 195, 198, 224, 231–233, 236, 282 – cross-wire 197, 309, 321 – oblique-wire 308, 309, 321 – Weber’s technique 195 K-wires (see also Wires) 4, 6, 28, 29, 31, 32–36, 40, 49, 74, 99, 114, 139, 151, 160, 192, 253, 275–278, 281, 282 Kirschner wires see K-wires Lengthening 6, 27, 36, 158, 201, 202, 204, 207, 209, 212, 214, 282, 289, 293, 296–301, 303, 306, 308, 309, 321, 323, 324 – in accordance with the anatomical axis 201 – in accordance with the mechanical axis 201 – arthrodesis 6, 298 – femur 201, 202, 204, 214, 292, 293, 296, 297 – foot 282 – forearm 209 – functionally permissible elongation 227 – monolocal 201

– over the intramedullary nail (LON) 209 – soft-tissue 6, 308 – tibia 6, 36 Levels (see also Method for the Unified Designation of External Fixation (MUDEF)) 4–6, 22, 24, 25, 27, 28–35, 38, 40–119, 121, 124, 129–136, 138–156, 158–161, 164, 165, 168, 169, 172, 174–179, 181, 183–188, 192, 201, 202, 204, 206–211, 213, 215, 222, 224, 227, 228, 231, 233, 234, 236–238, 240, 242–248, 251, 253, 255, 258, 260, 262, 266, 269, 270, 273–275, 277, 278, 283, 287, 291, 292, 299–301, 303, 304, 309, 319–321, 335, 339, 342, 344 Ligamentotaxis 157, 169, 175, 176, 184, 186, 274, 275, 289 L-shaped clips 8, 123, 131, 141, 159, 173 Metacarpals 142, 156, 158, 288, 339 Metatarsals 186, 274–278, 281, 300, 301 Method for the Unified Designation of External Fixation (MUDEF) 25–27, 28–34, 35, 36, 38, 40, 49, 74, 99, 108, 144, 179, 187, 333, 341–343 – contraindicated positions 35, 38, 41–44, 48, 50–73, 75–98, 100–107, 109–116, 333 – coordinates 28, 337 – designation of external support frame 34 – designation of half-pins 34 – designation of whole device 34 – designation of K-wires 33 – device for division of an extremity into levels 6 – levels 4–6, 22, 24, 25, 27–35, 38, 40–119, 121, 124, 129–136, 138–156, 158–161, 164, 165, 168, 169, 172, 174–179, 181, 183–188, 192, 201, 202, 204, 206–211, 213, 215, 222, 224, 227, 228, 231, 233, 234, 236–238, 240, 242–248, 251, 253, 255, 258, 260, 262, 266, 269, 270, 273–275, 277, 278, 283, 287, 291, 292, 299–301, 303, 304, 309, 319–321, 335, 339, 342, 344 – reference positions 13, 35–116, 118, 119, 130, 141, 144, 158, 173, 192, 251, 256, 285, 288, 293, 298, 302, 304, 322, 323, 333–338, 340 – safe positions 35, 38, 40–112, 114–116, 118, 119, 121, 131, 132, 139, 142, 146, 149, 151, 155, 159, 164, 174, 192, 298, 302, 333 – standard and additional symbols 28, 29 Modules (see also Assemblies, Devices, External supports) 6, 11–15, 17, 24, 25, 119, 121, 130, 131, 135, 136, 138, 140–142, 145, 152, 158, 159, 162, 164, 165, 168, 169, 173–176, 183, 184, 188, 190–192, 194, 195, 198, 201, 202, 204, 207, 209, 215, 216, 228, 236, 237, 241, 242, 245, 247, 250, 252, 254, 255, 260, 275, 276–280, 282, 283, 285–288, 291, 293, 294, 296, 298–300, 302, 304, 308, 319, 321–325, 341–349 – classification – first-order 341–349 – second-order 341–349 – third-order 341–349 – components – bolts 122, 123, 128, 131, 179, 181, 198, 334 – hinges 12, 17, 34, 124, 141, 145, 169, 171, 175, 176, 192, 201, 207, 209, 211–213, 221, 222, 228, 230, 240, 279, 281, 287, 289, 294, 296, 297, 299, 300, 302, 309

Index

– nuts 7, 19, 146, 150, 151, 175, 179, 181, 183, 224, 238–241, 256, 289, 307, 319, 334, 340 – plates 7, 13, 119, 129, 135, 136, 158, 171, 194, 207, 209, 211, 232, 238, 241, 245–249, 253, 256, 265, 271, 273, 275, 283, 284, 325 – posts 6, 7, 10, 19, 122, 123, 130, 131, 133, 141–147, 149, 150, 153, 155, 157, 159, 164, 173, 179, 181, 184–188, 252, 253, 255, 302, 304 – rings 4, 7, 22, 119, 129, 135, 141, 147–149, 154, 158, 159, 163, 169, 171–173, 179, 181–183, 186, 199, 221, 223, 224, 233, 236, 241, 268, 323 – rods 4, 7, 12, 14, 22, 25, 33, 34, 131, 134–136, 138, 139, 142, 146, 148, 150–156, 158, 159, 164, 165, 168, 169, 171, 173, 175, 176, 179, 181, 183, 184, 186, 188, 191, 194, 201, 209, 224, 230, 238, 247, 250, 255, 275, 277–282, 285, 289, 291, 298, 299, 303, 304, 306, 308, 309, 319, 344, 345 – washers 7, 19, 122, 130, 141, 159, 173 Monteggia fracture 149, 246, 247, 311 Myolysis 296, 297 Navicula (navicular bone) 275, 277 Neck-shaft angle 214, 244 Necrosis 204, 233, 276, 288, 297, 322 Nerves 6, 10, 21, 24, 25, 38, 131–134, 139, 142, 146, 149, 151, 155, 159, 164, 174, 191, 192, 201, 204, 207, 235, 256, 285, 286, 288, 294, 297, 299, 302, 303, 309, 322, 333, 335 – radial 151, 155 Neurovascular disorders 190, 191, 323 Nonunion (see also Pseudoarthrosis, False joints) 1, 5, 6, 228–235, 241, 243–246, 249, 251, 273, 274, 293, 296, 297, 302, 307, 308, 310, 311, 315, 319, 325 – atrophic 297 – hypertrophic 297 – hypotrophic 231 – treatment 228–235 Nuts 7, 19, 146, 150, 151, 175, 179, 181, 183, 224, 238–241, 256, 289, 307, 319, 334, 340 Orthopaedic (traction) table 6, 129, 139, 142, 160, 164, 165, 168, 198, 265 Osteoclasia 231, 234, 297 Osteogenesis (see also Regenerate) 1, 6, 13, 219, 229, 230, 249, 303, 308, 326 – hyperplastic type 229–231, 303 – hypoplastic type 202, 229, 232, 325 Osteomyelitis 228, 229, 290, 296, 297, 302, 303, 321 Osteosynthesis (see also External fixation) 1, 5–7, 13, 20, 22–27, 35, 117–122, 124, 141–143, 146, 147, 151–153, 158, 171–173, 175–177, 181, 183, 184, 190, 192, 198, 202, 205, 228, 230, 232–234, 236, 237, 239, 260–266, 267–269, 271, 273, 287, 290, 297, 299, 301, 304, 305, 308, 319, 320, 324, 326, 333, 341–345, 349 – alternating 1, 26, 193 – bilocal 1, 130, 141, 158, 173, 192, 233, 234, 299, 308, 309, 321 – bilocal distraction 205 – bilocal distraction-compression 198, 231, 232 – bilocal consecutive distraction-compression 231

355

– – – – – – – – – – – – – –

combinative 26, 249–251 combined 1, 4, 23, 26, 27, 234, 249, 290 compression 1, 230, 301 conjunctive 26 consecutive 1 distraction 202 external 1 extrafocal 1 internal 1, 6 intrafocal 1 monolocal 1 monolocal compression 229 monolocal distraction 192, 230 monolocal consecutive distraction-compression 192, 228, 229, 231 – monolocal synchronous distraction-compression 229 – polylocal 1, 198, 233 – polylocal compression-distraction 232, 308 – synchronous 1 Osteotomy 188, 190, 192, 198, 199, 202, 204, 206–211, 213–216, 220–224, 231, 242, 243–245, 269–271, 273, 278, 283, 297, 300, 303, 308 – trochanteric 243 – V-shaped 283 Outpatient treatment 131, 143, 254, 309 Patella 1, 171, 172, 174, 296, 298 Pelvis 5, 161, 243, 256–273, 274, 292 Phalanges 274–276 Pharmacotherapy 307 Physiotherapy 271, 302, 307, 309, 323 Pin-tract infection (see also Complications, Infections, Inﬂammation of soft tissues) 12, 24, 25, 28, 38, 149, 151, 256, 303, 309, 321, 333 Plate 7, 13, 119, 129, 135, 136, 158, 171, 194, 207, 209, 211, 232, 238, 241, 245–249, 253, 256, 265, 271, 273, 275, 283, 284, 325 Pliers 7, 237, 243, 246, 248, 252, 255 Polylocal myofasciodeses 296 Positions see Atlas for Insertion of Transosseous Element “Reference Positions” Posts 6, 7, 10, 19, 122, 123, 130, 131, 133, 141–147, 149, 150, 153, 155, 157, 159, 164, 173, 179, 181, 184–188, 252, 253, 255, 302, 304 – female 7, 19, 123, 130, 141, 159, 173 – female slotted 10 – male 7, 123, 130, 141, 159, 173 Postoperative period 18, 26, 118, 119, 129, 141, 189, 192, 228, 230, 241, 293, 303–321 Preoperative preparation 117, 118, 129, 192, 219, 236, 302 Pseudoarthrosis (see also Nonunion, False joints) 198, 228–235, 297, 302, 303, 319 Radius 21, 26, 29, 31–35, 49, 74–98, 142–145, 147, 149–152, 153–156, 158, 200, 209, 231, 246–251, 253, 289, 290, 303, 320, 338, 339 Range of motion 76, 81, 306, 309, 321, 325 Reduction 5, 10, 17, 24, 25, 27, 28, 39, 124, 131–136, 138–144, 146–149, 151–161, 164–201, 209, 224, 227,

356

Index

231, 232, 242–246, 248, 249, 251, 252, 254, 262–264, 266–271, 274–279, 285, 286, 288, 289, 291, 292, 294, 301, 302, 304–306, 309, 319, 320, 324–326 Reference positions (see also Positions, Safe positions) 13, 25, 35–116, 118, 119, 130, 141, 144, 158, 173, 192, 251, 256, 285, 288, 293, 298, 302, 304, 322, 323, 333–338, 340 Reﬂexotherapy 117 Refracture 326 Regenerate (see also Osteogenesis) 25, 194, 198, 201, 202, 207, 209, 211, 212, 214, 223, 227, 228, 230–232, 234, 254, 283, 293, 296, 299, 302, 305, 308, 309, 319–321, 325 – hypoplastic distraction 202, 232, 325 – interfragmentary 198 – trapezoidal 198, 209, 212 – wedge-shaped 198, 211 Release 100–102, 237, 252, 255, 277, 282, 296, 297, 299, 305, 320, 322 – arthroscopic 296, 297, 299, Reamers 237, 239, 240, 242, 243, 246, 248 Repositioning (see also Bone fragments, Reduction, Barabash cube) 5, 15, 18, 20, 21, 27, 118, 119, 122, 124, 151, 152, 161, 164, 165, 173, 191, 192, 198, 201, 228, 246, 263, 265, 267, 268, 271 Rigidity 5, 12, 15, 20, 22, 23–28, 119, 120, 122, 124, 143, 162, 164–166, 168, 169, 171, 175, 176, 191, 183, 248, 251, 261, 262, 266, 283, 285, 288, 297, 302–305, 307, 308, 324, 325, 341–349 – abduction 347, 348 – adduction 347, 348 – bone fragment 15, 23, 341 – coefficient 343–349 – extension 343 – ﬂexion 343 – index 345, 346, 349 – inward rotation 343, 345 – longitudinal – compression 343 – distraction 343 – osteosynthesis 22, 124, 304, 341, 342 – outward rotation 343–346, 348 – testing 27, 341–349 Rod 4, 7, 12, 14, 22, 25, 33, 34, 131, 134–136, 138, 139, 142, 146, 148, 150–156, 158, 159, 164, 165, 168, 169, 171, 173, 175, 176, 179, 181, 183, 184, 186, 188, 191, 194, 201, 209, 224, 230, 238, 247, 250, 255, 275, 277–282, 285, 289, 291, 298, 299, 303, 304, 306, 308, 309, 319, 344, 345 Safe positions (see also Positions, Reference positions) 35–116, 118, 119, 121, 131, 132, 139, 142, 146, 149, 151, 155, 159, 164, 174, 192, 298, 302, 333 Scapula 34, 131–134, 242, 252–254, 283–285 Schanz screws (S-screws) 4, 6, 25, 28, 29, 34, 35 Shape of lower extremities 201, 218, 220–228 – “ideal” 220, 226 – shin 171, 179, 224, 228, 293

Shortening 38, 194, 200–203, 207, 209, 214, 218, 224, 225, 228–231, 234, 247–249, 293, 296, 297, 299, 306, 321 Skeletal traction (see also Traction) 6, 27, 121, 122, 131, 132, 134–136, 138, 139, 141–143, 148–151, 153–156, 160–169, 174, 175, 179, 181, 183, 184, 198, 228, 265–267 Sliver see Bone fragments Smith’s fractures 156 Steinmann rod 4, 25, 33 Surgical drill 6, 9 ‘T’ wrench 8 Talipes 299 – valgus 202, 218, 220, 277–279, 282, 300 – varus 202, 209–211, 217, 218, 220, 223, 277–279, 282 Talus 34, 274, 277 – fracture 34, 274, 277 Tarsals 186, 274–278, 281, 300, 301 Tendons 6, 186, 190, 191, 271, 278, 282, 293, 295, 296, 299, 300, 324 – Achilles 186, 190, 282, 299, 300 Testing 27, 270, 271, 273, 274, 308, 310, 319, 341–349 – biochemical 308 – clinical 271, 273, 310, 319 – rigidity 27, 341–349 Tibia (see also Fibula) 5, 21, 27, 29, 33, 34, 36, 108–116, 118, 160, 168, 169, 172–190, 197, 199, 202, 203, 220–222, 224, 227, 232–235, 239, 244, 245, 254, 274, 277, 278, 295, 299–301, 303, 315, 337, 341 – defect 36, 197, 232, 233, 235, 303 – fracture 171–190 – nonunion 245 Tibiofibular diastasis 184, 186, 187, 190 Tools – drills 6, 9, 121, 122, 240, 241, 244, 246, 251–253, 304, 321 – extracortical bone clamp 10 – pliers 7, 237, 243, 246, 248, 252, 255 – reamers 237, 239, 240, 242, 243, 246, 248 – wrenches 8 Traction (see also Skeletal traction) 6, 7, 27, 121, 122, 131, 132, 134–136, 138, 139, 141–143, 148–151, 153–156, 160–169, 174, 175, 179, 181, 183, 184, 194, 195, 198, 228, 265–267 – clip 7, 9, 123, 144, 186, 198, 225, 247, 248, 255, 307, 308 – one-stage forced 198 Transosseous elements 1, 4, 6, 11, 12–124, 129–131, 133, 138, 140–144, 147, 149, 151, 157–161, 164, 168, 170–175, 177, 179, 183, 184, 188, 191, 192, 194, 195, 198, 201, 209, 214, 227–229, 232–234, 236, 241, 247, 251, 253, 256, 260, 267, 268, 273, 282, 285, 288, 289, 293, 297–300, 302–304, 306, 308, 309, 319–325, 333–340, 341, 342, 345 – console 1, 4, 22, 34, 41–73, 75–98, 100–107, 109–112, 114, 115, 151, 170, 177, 256 – half-pins see Half-pins – insertion see Insertion of transosseous elements

Index

– K-wires 4, 6, 28, 29, 31, 32–36, 40, 49, 74, 99, 114, 139, 151, 160, 192, 253, 275–278, 281, 282 – reinsertion 118, 321 – Steinmann rods 4, 25, 33 – S-screws 4, 6, 25, 28, 29, 34, 35 – transsegmental elements 6, 22, 25, 33 – wires see Wires Transport 36, 131, 142, 194, 195, 198, 232, 235, 266, 302, 303, 308, 309, 321 – bone 36, 195, 302, 303, 308 – cross-wire bone 194, 309, 321 – fibula 232, 235, 303 – oblique-wire bone 308, 309, 321 Trochanter 29, 160, 161, 162, 214, 240–243, 259, 289, 291 – osteotomy 243 Ulna 21, 26, 27, 31, 32, 34, 35, 49–73, 74, 89, 90, 98, 142, 144, 145–157, 200, 209, 231, 232, 239, 246–251, 286–290, 303, 311, 320, 337–341 Washers 7, 19, 122, 130, 141, 159, 173 – conical 7 – lock 7 – serrated 7 – slotted 7, 188 – spherical 7

357

Weight-bearing 269, 271, 304, 319 Wires (see also Insertion of transosseous elements, K-wires, Transosseous elements) – arched bending 139, 146, 149, 151, 173, 179, 188, 190 – console 4, 6, 22, 25, 33, 34, 129, 131, 139, 146, 151–153, 155, 158–160, 162, 171–173, 178, 179, 181, 182, 186, 187, 190, 192, 253–256, 275–277, 291 – designation 33 – diafixing 171, 172, 245, 284, 287, 291, 301, 341 – distraction-guiding 198, 233, 234, 236 – feather 12, 13 – insertion 12, 13, 24, 27, 121, 132, 141, 151, 172, 176, 236–238, 241–244, 246, 249, 252, 253, 278, 302, 303, 322, 323, 333 – module – fixation bolts 7, 122, 131 – reamers 237, 239, 240, 242, 243, 246, 248 – single-facet 12, 13 – smooth 7 – stop wires 7 – tensioner 7, 8, 122, 123, 185, 307 – three-facet 13 – transsegmental 25 X-ray contrast markers 131, 143, 160, 273