Disorders of the lunotriquetral joint Atlas of the Hand Clinics - Volume 9, Number 1, March 2004

Author: David S. Ruch

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Atlas of the Hand Clinics Copyright © 2006 Saunders, An Imprint of Elsevier

Volume 9, Issue 1 (March 2004) Issue Contents: (Pages viii-128)

1 2 3 4 5 6 7 8 9 10

viii-viii Foreword Osterman A ix-ix Disorders of the lunotriquetral joint Ruch DS 1-6 Anatomy of the lunotriquetral joint Mastella DJ 7-15 Lunotriquetral dissociation: pathomechanics Garcia-Elias M 17-24 Lunotriquetral instability: clinical findings Kalainov DM 25-38 The role of wrist arthroscopy in the diagnosis and treatment of lunotriquetral joint injuries Hanker GJ 39-58 Combined lunotriquetral and triangular fibrocartilage complex ligamentous injuries Geissler WB 59-66 Lasers and electrothermal devices in the treatment of lunotriquetral instability Nagle DJ 67-82 Open treatment options for lunotriquetral instability and dissociation Moran SL 83-97 Lunotriquetral arthritis and ulnar impaction syndrome Bindra RR

11

99-104 Lunotriquetral arthritis: clinical and radiographic assessment Evans PJ

12

105-113 The role of arthroscopy in the management of lunotriquetral arthritis Kuzma G

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115-128 Lunotriquetral arthrodesis Novak V

Atlas Hand Clin 9 (2004) ix

Foreword

A. Lee Osterman, MD Consulting Editor

The lunato-triquetral (LT) intrinsic ligament has always been a stepchild compared with its sister, the scapholunate intrinsic ligament. Fortunately Dr. Ruch and his collaborators have corrected that neglect in this issue of the Atlas of the Hand Clinics. It is exciting to have so much useful LT information organized in this compact issue. This deﬁnitive work emphasizes the new appreciation of LT anatomy and cogently explains the pathophysiology of its injury. The various treatment algorithms available to the surgeon are covered in explicit detail. This body of articles is destined to be quoted as the ‘‘Bible of LT references.’’ Congratulations to Dr. Ruch and his authors for this wonderful eﬀort on our behalf. A. Lee Osterman, MD President The Philadelphia Hand Center 901 Walnut Street Philadelphia, PA 1907

1082-3131/04/$ - see front matter Ó 2004 Elsevier Inc. All rights reserved. doi:10.1016/j.ahc.2003.12.004

Atlas Hand Clin 9 (2004) xi

Preface

Disorders of the lunotriquetral joint

David S. Ruch, MD Guest Editor

Disorders of the lunotriquetral articulation of the wrist remain a challenging problem for hand surgeons in the twenty-ﬁrst century. The anatomy is complex and diﬃcult to repair or reconstruct. The pathophysiology remains diﬃcult. The diagnosis often is delayed or missed, and surgical treatment continues to be fraught with complications. It is for this reason that this edition of Atlas of the Hand Clinics is devoted to disorders of the lunotriquetral articulation. The text is organized in a logical progression. First, expert anatomists discuss the anatomy and kinematics of the lunotriquetral articulation. Next, our current understanding of the pathophysiology as it relates to the spectrum of ulnar-sided wrist pain is discussed. The clinical diagnosis, provocative maneuvers, and characteristic history are presented, followed by a section on imaging modalities. In the treatment of the disorders, it becomes immediately apparent that these injuries may seem to be isolated, but are often part of a spectrum of ulnar-sided injury. The treatment of these disorders reﬂects the progressive nature of the injury. The association of lunotriquetral injuries with ulnar carpal abutment is discussed, together with its management. Next, the spectrum of ulnar-sided injury is discussed with the relationship of the lunotriquetral joint to injuries to the triangular ﬁbrocartilage and to the midcarpal joint. Finally, techniques of reconstruction of the articulation, including soft tissue reconstructions and arthrodeses, are discussed, from a technical expertise perspective to the results of surgical treatment. As a guest editor, I am pleased to present this issue. I am also deeply indebted to the experts who have committed their time and energy to bringing this edition to publication. Each of these individuals was asked because of their experience and expertise with the management of this particular disorder. I am conﬁdent that this work represents the best and most current update on this problematic area of the wrist. Finally, I would like to thank WB Saunders and the editorial staﬀ, including Deb Dellapena, for their support and guidance in bringing this edition to press. The behind-the-scenes work makes the publication of a text like this extraordinarily easy. David S. Ruch, MD Wake Forest University School of Medicine Department of Orthopaedic Surgery Medical Center Boulevard Winston-Salem, NC 27157-1070, USA E-mail address: [email protected] 1082-3131/04/$ - see front matter Ó 2004 Elsevier Inc. All rights reserved. doi:10.1016/S1082-3131(03)00080-3

Atlas Hand Clin 9 (2004) 1–6

Anatomy of the lunotriquetral joint Daniel J. Mastella, MD, David S. Zelouf, MD* The Philadelphia Hand Center, 700 South Henderson Road, Suite 200, King of Prussia, PA 19406, USA

The wrist is a complex set of articulations that combine to allow hand motion with six degrees of freedom. Historically, the scaphoid articulations have received the greatest attention. This article examines the anatomy of the lunotriquetral joint. Understanding the anatomy of the lunotriquetral joint helps in understanding the pathology of the ulnar side of the wrist.

Osteology The triquetrum (the triangular, pyramidal, or cuneiform) sits between the lunate laterally and the hamate distally. The lunotriquetral articulation is ﬂat and triangular. The triquetral hamate articulation is spiral (Fig. 1) and lies approximately 90 from the articular surface of the distal hamate with the fourth and ﬁfth metacarpals. The anterior surface of the triquetrum has a proximal nonarticular surface with vascular foramina and a distal oval articular surface for the pisiform [1]. The triquetrum has a proximal articular surface that has only a thin layer of articular cartilage and articulates only with the ulnar sling mechanism (Figs. 2–4). The lunotriquetral joint is positioned ulnar and distal to the scapholunate joint (Figs. 5 and 7; see Fig. 4). The lunotriquetral interosseous ligament is continuous with the proximal surfaces of the two bones and conceals this articulation (Fig. 9). The LTIO can be located nearly in line with the apex of the triangular ﬁbrocartilage complex [1]. The lunate (semilunar) articulates with the capitate, and in a type II lunate, the hamate distally. It articulates with the radius and TFCC proximally and the scaphoid laterally. The medial surface of the lunate articulates with the triquetrum through a small triangular articulating surface. Occasionally the lunotriquetral articulation fails to form correctly, resulting in a coalition. Rather uncommon in Caucasians (0.5%), carpal coalition is much more common in individuals of West African descent. For example, 9.5% of Hausa women in Nigeria have a carpal coalition. More than 50% of cases are bilateral. There are four types of carpal coalition: Type Type Type Type

I synchondrosis II (incomplete) synostosis with a notch III complete synostosis IV complete synostosis associated with other carpal anomalies

A coalition probably represents a failure of separation during embryologic development. The lunotriquetral coalition is by far the most common. Several syndromes are associated with carpal coalition. These include Ellis-van Creveld syndrome, hand-foot-uterus syndrome, hereditary symphalangism, diastrophic dwarﬁsm, Holt-Oram syndrome, and the otopalatodigital syndrome.

* Corresponding author. E-mail address: [email protected] (D.S. Zelouf). 1082-3131/04/$ - see front matter Ó 2004 Elsevier Inc. All rights reserved. doi:10.1016/S1082-3131(03)00081-5

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Fig. 1. Cadaveric dissection of a left wrist viewed dorsally from distal to proximal. Notice the helicoid shape of the triquetrohamate joint and the small type II lunate. L, lunate; T, triquetrum; C, capitate; H, hamate.

Vascularity The blood supply to the triquetrum comes from branches of the ulnar artery, the dorsal intercarpal arch, and the palmar intercarpal arch. The nutrient vessels enter the triquetrum at its dorsal and palmar nonarticular surfaces. The dorsal blood supply is dominant in most specimens, supplying 60% of the bone. The volar vessels enter the triquetrum proximal and distal to its articulation with the pisiform. The volar blood supply forms an anastomosis with the dorsal vessels in 86% of specimens [2]. The blood supply to the lunate comes from dorsal and volar in 80% of specimens and is volar alone 20% of the time. The lunate blood supply is tenuous because most of the bone is covered with articular cartilage. There are three major intraosseous anastomotic variants in the lunate. These are the Y, I, or X patterns, with the Y being most common [2].

Fig. 2. The same dissection viewed dorsally from proximal to distal with the proximal articulating surface of the proximal carpal row just distal to the retractor. The forceps are on the ulnar sling attachment to the triquetrum. Notice that although the scaphoid (S) and the lunate (L) have well developed articular surfaces for articulation with the radius, the triquetrum (T) has a much more poorly developed proximal articular surface. The dorsal hamate (H) and capitate (C) can be seen just past the proximal carpal row.

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Fig. 3. The wrist is hyperﬂexed, viewed dorsally (distal is lower and proximal is above). The retractor is on the dorsal aspect of the TFCC and the scaphoid facet, lunate (L) facet, and the soft tissue articulation of the triquetrum (T) can be seen clearly. The capitate and hamate are seen below the proximal carpal row.

Ligaments The proximal row of the carpus has no tendinous origins or insertions and is thus referred to as an intercalated segment. As a result of this, its articulations and ligaments dictate all proximal carpal row motions. The triquetrum is the most ﬁxed carpal bone in the proximal row, and it has the greatest number of ligamentous attachments [3]. There are volar and dorsal extrinsic wrist ligaments that attach to the triquetrum. The volar extrinsic triquetral ligaments are the ulnotriquetral ligament, the ulnar arm of the arcuate ligament (lunocapitate ligament), and the meniscal homolog of the ulnar sling mechanism. The ulnotriquetral ligament has a fenestration between the radiocarpal and pisotriquetral joints. This fenestration admits an arthroscope after signiﬁcant ligamentous disruption and in some ligamentously lax individuals. The dorsal triquetral extrinsic ligaments are the dorsal radiocarpal and the dorsal intercarpal ligaments. None of the ligaments that connect the proximal carpal row to the distal carpal row attach to the lunate. The intrinsic carpal ligaments that attach to the triquetrum are the lunotriquetral interosseous ligament (LTIO), and the triquetrohamate ligament. The triquetrum also has ligamentous attachments to the pisiform at its volar articulation, adding additional stability to the triquetrum by way of the pisiform attachments to the hamate and ﬁfth metacarpal. Much like the scapholunate interosseous ligament, the lunotriquetral interosseous ligament has three components: a dorsal ﬁbrous portion, a volar ﬁbrous portion, and a proximal membranous portion. The dorsal portion of the LTIO ligament receives ﬁbers from the

Fig. 4. Excised proximal carpal row with forceps at the dorsal scapholunate ligament. Notice that with the scapholunate joint vertical, the lunotriquetral joint is angled 45 distal to it. The ulnar sling tissue is seen surrounding the triquetrum. L, lunate; T, triquetrum; S, scaphoid.

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Fig. 5. The excised proximal carpal row is viewed distally, looking at the midcarpal surface. The forceps are on the distal volar scaphoid, holding it extended. In this position, the lunate is balanced between the scaphoid and the triquetrum. L, lunate; T, triquetrum; S, scaphoid.

overlying dorsal radiocarpal ligament (see Fig. 5). At the lunotriquetral joint, the volar ﬁbrous portion of the lunotriquetral interosseous ligament is thicker and more critical for lunotriquetral stability than is the dorsal portion (Fig. 8, see Fig. 6). The dorsal portion of the LTIO ligament is important for control of lunotriquetral rotation. The volar portion of the LTIO ligament is reinforced by ﬁbers from the ulnocarpal ligaments. The LTIO ligament dorsiﬂexes the lunate with the triquetrum in ulnar deviation. The extrinsic ligaments that help stabilize the lunotriquetral articulation include the dorsal radiocarpal and dorsal intercarpal (scaphotriquetral) ligaments and the volar long and short radiolunate ligaments, lunocapitate (arcuate), ulnotriquetral, and ulnolunate ligaments [4,5].

Kinematics The lunotriquetral joint has less motion than the scapholunate joint [1]. Carpal motion can be described by using the analogy of a screw axis with obligatory motion in translation and rotation [6]. Radioulnar motion in the proximal carpal row is linked to wrist ﬂexion–extension. This coupled motion is driven by the scaphoid-trapezium-trapezoid joint laterally and the helicoid triquetrohamate joint medially. The lunate is ﬂexed by the scaphoid and is extended and dorsally displaced by the triquetrum (Fig. 5). If either the scapholunate or lunotriquetral ligaments fail, with some degree of extrinsic ligament failure, the lunate assumes a dorsiﬂexed or volarﬂexed position (DISI or VISI) driven by the lunate’s remaining ligaments. This description is helpful in understanding the ﬂuid motions at the wrist. Several investigators have also studied wrist kinematics after sectioning various ligaments [7,8]. After cutting the lunotriquetral interosseous ligament, no signiﬁcant change was seen in

Fig. 6. Volar view of the excised proximal carpal row. The pisotriquetral articulation can be seen at left. The forceps are at the scaphoid attachment of the scapholunate interosseous ligament. Notice the stout ﬁbers of the volar lunotriquetral interosseous ligament distal and volar to the P-T articulation. L, lunate; T, triquetrum; P, pisiform.

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Fig. 7. The proximal carpal row disarticulated, viewed dorsally at the midcarpal surfaces. Note that the lunotriquetral face of the lunate is much smaller than the scapholunate, triangular in shape, and angled 45 distally to the scapholunate joint. L, lunate; T, triquetrum; S, scaphoid.

the motion of the proximal row. After additionally sectioning the dorsal intercarpal and dorsal radiocarpal ligaments, there was a signiﬁcant increase in abnormal carpal motion. Most signiﬁcantly, the lunotriquetral joint was hypermobile. Without the lunotriquetral constraint, in ulnar deviation, the scaphoid and lunate abnormally extend without the triquetrum following. Hamate-triquetrum contact resulted in more ulnar deviation and less extension. Lunotriquetral motion increased and the triquetrum assumed a more proximal position, disrupting Gilula’s lines. Overall, ulnar deviation resulted in dissociative instability (VISI). In radial deviation, the loss of lunotriquetral association allowed the scaphoid and lunate to ﬂex excessively. The triquetrum continued to follow the hamate. With ﬂexion and extension, the lunotriquetral motion doubled that seen in the intact wrist.

Clinical correlation Clinically, the ﬁnding of a click on the ulnar side of the wrist is well known and was found in the study by Hori et al after sectioning the lunotriquetral interosseous ligament and the dorsal radiocarpal and intercarpal ligaments. They found that as the wrist was deviated from neutral to ulnar deviation under axial compression, the lunate abruptly rotated from a palmar ﬂexed to dorsiﬂexed position, producing an audible clunk. This ﬁnding correlates with Lichtman’s midcarpal clunk test [7]. Reeﬁng of the ulnar arm of the arcuate ligament can contribute to

Fig. 8. The triquetrum viewed volarly with the upper blade of the forceps on the pisotriquetral facet. The proximal articulation of the triquetrum can be seen to the left and below the P-T facet. The lunotriquetral facet is seen obliquely on the extreme left. Notice the stout LTIO ligament superﬁcially at the lunotriquetral joint. T, triquetrum.

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Fig. 9. The triquetrum viewed from dorsal and distal with the helicoid T-H facet at right and the lunotriquetral facet at left. The LTIOL is U-shaped and obscures the joint everywhere but at the midcarpal junction of the lunate and triquetrum. T, triquetrum.

stabilizing a midcarpal instability pattern when advanced distally on the capitate to hold the lunotriquetral joint (proximal row) out of VISI [9].

Summary In the diagnosis of ulnar-sided wrist pain, lunotriquetral problems must be diﬀerentiated from various other diagnoses, including extensor carpi ulnaris tendonitis, triangular ﬁbrocartilage pathology, distal radioulnar abnormality, pisotriquetral arthritis, lunate or ulnar chondromalacia, and carpal instability. A thorough understanding of lunotriquetral anatomy helps surgeons better diagnose and treat ulnar-sided wrist pain.

References [1] Adams BD, Divelbiss BJ. Anatomy of the wrist ligaments. In: Trumble TE, editor. Carpal fracture-dislocations. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2002. p. 1–6. [2] Alexander CE, Lichtman DM. Triquetrolunate instability. In: Alexander AH, editor. The wrist and its disorders. Philadelphia, PA: WB Saunders Co.; 1997. p. 307–15. [3] Horii E, Garcia-Elias M, An KN, et al. A kinematic study of luno-triquetral dissociations. J Hand Surg [Am] 1991; 16(2):355–62. [4] Lichtman DM, Bruckner JD, Culp RW, et al. Palmar midcarpal instability: results of surgical reconstruction. J Hand Surg [Am] 1993;18(2):307–15. [5] Panagis JS, Gelberman RH, Taleisnik J, et al. The arterial anatomy of the human carpus. Part II: the intraosseous vascularity. J Hand Surg [Am] 1983;8(4):375–82. [6] Ruby LK, Cooney WP III, An KN, et al. Relative motion of selected carpal bones: a kinematic analysis of the normal wrist. J Hand Surg [Am] 1988;13(1):1–10. [7] Spinner M. Kaplan’s functional and surgical anatomy of the hand. 3rd edition. Philadelphia, PA: JB Lippincott Co.; 1984. p. 446. [8] Viegas SF, Patterson RM, Peterson PD, et al. Ulnar-sided perilunate instability: an anatomic and biomechanic study. J Hand Surg [Am] 1990;15(2):268–78. [9] Zancolli ER III. Localized medial triquetral-hamate instability: anatomy and operative reconstruction-augmentation. Hand Clin 2001;17(1):83–96, vii.

Atlas Hand Clin 9 (2004) 7–15

Lunotriquetral dissociation: pathomechanics Marc Garcia-Elias, MD, PhDa,*, Marco J.P.F. Ritt, MD, PhDb a

Institut Kaplan Hand and Upper Extremity Surgery, Passeig de la Bonanova, 9, 2on, 2a 08022 Barcelona, Spain b de VU Medisch centrum, Department of Plastic and Reconstructive Surgery, De Boelelaan 1117 1081 HV Amsterdam, The Netherlands

Unless properly treated, traumatic disruptions of the lunotriquetral (LTq) supporting ligaments may result in substantial instability to the carpus, which is one of the most common causes of ulnar-sided wrist pain. The literature concerning this problem is scarce, however, and often misleading. Most descriptions of the mechanisms by which these ligaments fail frequently are based on speculations without biomechanical corroboration. The consequences of such an injury to the overall carpal mechanics (kinematics and kinetics) are better recognized, but numerous questions remain unanswered. More research is needed to clarify the mechanisms explaining the symptoms in these patients and how to deal with them. This article reviews the diﬀerent contributions found in the literature regarding LTq dissociation. Functional anatomy of the lunotriquetral supporting ligaments The triquetrum has been regarded as the keystone in the coordination of motions occurring at four articulations (ulnocarpal, LTq, triquetrohamate, and pisotriquetral joints). The triquetrum also is important as the main stabilizer of the wrist against the important pronosupination torques generated during hand function. Because each of the four joints around the triquetrum requires ligaments to ensure stability, it is not surprising to ﬁnd almost all nonarticular surfaces of the bone covered by an intricate arrangement of ligament attachments (Fig. 1). Some ligaments are called extrinsic because they connect the carpus (triquetrum) with the radius or ulna. Others are called intrinsic ligaments because they have origin and insertion within the carpus. Anatomic, histologic, and biochemical differences exist between the two types [1–4]. The extrinsic ligaments are stiffer but with lower yield strength than the intrinsic ligaments [2]. This difference implies a different mode of failure under stress: The extrinsic ligaments tend to fail through their midsubstance, whereas the intrinsic ligaments seem more frequently to be avulsed than ruptured [5,6]. From a functional point of view, the ligaments converging onto the triquetrum may be subdivided into three major groups: (1) intrinsic LTq ligaments, (2) radioulnocarpal ligaments, and (3) midcarpal ligaments. The connections and mechanics of the pisotriquetral joint are not discussed in this article. Intrinsic lunotriquetral ligaments The LTq joint is tightly constrained by two intrinsic—palmar and dorsal—LTq interosseous ligaments. They are formed by stout colinear fascicles of collagen ﬁbers connecting the palmar and dorsal aspects of the two bones. In between the two ligaments, there is a ﬁbrocartilaginous membrane closing the joint proximally [3,4,7,8]. Results of material property testing of the LTq ligaments suggest that the palmar LTq ligament is stronger than the dorsal ligament (average yield * Corresponding author. E-mail address: [email protected] (M. Garcia-Elias). 1082-3131/04/$ - see front matter Ó 2004 Elsevier Inc. All rights reserved. doi:10.1016/S1082-3131(03)00075-X

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Fig. 1. Schematic representation of the ligaments attached to the triquetrum (Tq) as seen from the radial side, the lunate having been removed. The LTq joint is linked directly by three structures: (1) palmar LTq ligament, (2) dorsal LTq ligament, and (3) proximal LTq membrane. The ulna is connected with the triquetrum by means of (4) the palmar ulnotriquetral ligament. (5) The radiotriquetral ligament is wide and fan-shaped and is key in the prevention of carpal collapse. The midcarpal joint is constrained palmarly by two fascicles: (6) the triquetrum-hamate ligament and (7) the triquetrum-capitate ligament, both of which are important midcarpal stabilizers. The triquetrum is connected dorsally with the trapezium and trapezoid by means of (8) the dorsal intercarpal ligament and with the scaphoid by means of (9) the dorsal scaphotriquetral ligament. TFC, triangular ﬁbrocartilage.

strengths 301N and 121N), and the proximal portion is the weakest (64N) [3]. This is the exact opposite situation as found on the scaphoid side of the lunate, where the dorsal scapholunate ligament is the strongest structure [1]. The lunate could be thought of as a ‘‘torque-suspended’’ bone between the scaphoid and the triquetrum, much in the manner of a spring. Unless perforated by age or injury [9], the proximal LTq membrane prevents communication between the radiocarpal and midcarpal joint spaces. It needs to be understood that a defect at this level is not a sign of instability. The proximal membrane contributes little to overall LTq stability. The most distal ﬁbers of palmar and dorsal LTq ligaments often are connected to their corresponding scapholunate ligaments, forming the so-called scaphotriquetral ligaments, which enhance the depth of the lunocapitate articulation [10]. Despite such a dense arrangement of ligaments between the two bones, this joint is allowed a substantial amount of rotational [11,12] and translational [13] motion during wrist rotations. Radioulnocarpal ligaments Most extrinsic ligaments across the radioulnocarpal joint are oriented obliquely relative to the longitudinal axis of the forearm. Based on this orientation, they may be subdivided into two

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groups: (1) ligaments that prevent excessive passive supination of the proximal row relative to the forearm (antisupination ligaments) and (2) ligaments that control passive pronation (antipronation ligaments) [14,15]. Many ligaments act synergistically to prevent the proximal row from passively supinating beyond normal. All of the ligaments insert into the triquetrum: (1) the ulnotriquetral ligament, which originates at the fovea that exists at the base of the ulnar styloid, constituting the palmar margin of the prestyloid recess; (2) the ulnolunate ligament, which arises from the palmar edge of the triangular ﬁbrocartilage and runs obliquely toward its distal insertion into the anterior aspect of the lunate; and (3) the dorsal radiotriquetral ligament, which is a wide, fan-shaped ligament that connects the dorsal edge of the distal radius to the dorsal rim of the triquetrum [4,16–19]. Two major ligaments prevent the proximal row from passively pronating beyond normal: (1) the radioscaphocapitate ligament, which originates on the palmar margin of the radial styloid process and inserts into the capitate, and (2) the long radiolunate ligament, which emerges from the palmar edge of the radius and inserts into the palmar surface of the lunate. None of these structures is inserted directly into the triquetrum, explaining this bone’s relative vulnerability against pronation torques. Midcarpal ligaments The triquetrum is connected strongly to the distal carpal row by means of the palmar triquetral-hamate-capitate (TqHC) ligamentous complex, also known as the ulnar sector of the ‘‘arquate’’ ligament [17,20–23]. The TqHC complex consists of a group of fan-shaped fascicles formed by dense collagen ﬁbers that connect the distal anterior edge of the triquetrum to the palmar aspects of the hamate and capitate. This ligament also may be included into the group of ligaments that prevent the distal carpal row from passively supinating beyond normal. The only dorsal midpalmar crossing ligament is the so-called dorsal intercarpal ligament. It arises from the dorsal ridge of the triquetrum; courses transversely along the distal edge of the lunate; and fans out to insert on the dorsal rim of the scaphoid, the trapezium, and the trapezoid bones [4,17,24]. Because of its disposition, this ligament can be characterized as an antipronation ligament. There is no dorsal or medial ligament between the triquetrum and hamate. Because the midcarpal joint is not a true hinge articulation, vertically oriented ligaments should not be expected to be present. Their absence is substituted functionally by the extensor carpi ulnaris tendon, the thick sheath of which may act as a dynamic joint stabilizer [25].

Kinematics of the lunotriquetral joint The bones of the proximal carpal row form a highly functional adaptable unit, permitting a large range of motion of the hand: ﬂexion-extension, radial-ulnar deviation, and some rotation. During hand motions, the proximal carpal row undergoes adaptive changes, dictated by the geometry of the articular surfaces of the carpal bones and by the diﬀerent ligaments’ function. In radial deviation, the obliquely oriented scaphoid is forced to ﬂex palmarly, largely based on its bony geometry. By contrast, the lunate has a strong tendency to rotate dorsally, toward extension, as a result of its dorsopalmar wedge shape [26]. Nonetheless, the conﬁguration of the scaphoid, aided by the peripheral location of the interosseous scapholunate ligament, results in a large moment arm, which forces the lunate to follow against its tendency and rotate into ﬂexion, a rotation that is transmitted to the triquetrum, provided that the LTq ligaments are intact. In any case, the amount of ﬂexion exhibited by the triquetrum is always inferior to that of the lunate, owing to its important, palmar midcarpal crossing connections. The helicoidal geometry of the triquetrohamate joint plays an important role in ulnar deviation. As emphasized by Weber [27], the hamate has a proximal-dorsal articular facet that resembles a helicoid (ie, a twisted plane about a ﬁxed line). As a consequence, when in ulnar deviation, the triquetrum glides distally on this helicoid, and the bone is forced to rotate into extension [27]. Aided by the oblique shape of the LTq interface, the lunate also is forced to follow the triquetral motion and extends, taking the scaphoid along into an erect position [28,29].

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It seems obvious that the intercalated lunate is in need of constraints on both sides to counteract the above-mentioned torques. Yet the connections between triquetrum and lunate, although strong, are not as taut as not to allow mutual mobility. During maximal radioulnar deviation, there is an average 2.5-mm proximal shift of the triquetrum relative to the lunate, ranging from 0 to 5.2 mm [13]. Similarly, during maximal ﬂexion-extension, there is an average 18 rotation between the two bones [12]. From a kinematic viewpoint, the LTq joint cannot be thought of as one functional block without intrinsic mobility.

Stabilizing mechanism of the lunotriquetral joint A joint is considered mechanically stable when it is able to bear physiologic loads without yielding [30]. For a wrist to be considered mechanically and clinically unstable, aside from exhibiting a kinetic dysfunction, it has to have symptoms, usually in the form of sporadic or permanent pain. For the LTq joint to be clinically stable, a proper interaction between articular surface geometry and soft tissue constraints is necessary. Following is a description of the mechanisms by which the LTq joint remains stable under load. Under axial load, the distal carpal row exerts an axial compressive force onto the proximal row bones. Because of its oblique orientation relative to the long axis of the forearm, under such compressive load, the scaphoid tends to rotate into ﬂexion and pronation [31,32]. If the interosseous ligaments connecting transversely the bones of the proximal row were intact, the ﬂexion and pronation moment exhibited by the scaphoid would be transmitted to the lunate and the triquetrum. As a consequence, the unconstrained proximal row would rotate into ﬂexion and pronation were it not for the presence of the midcarpal crossing ligaments, being particularly important in the palmar TqHC ligamentous complex. Failure of this ligament results in a typical carpal collapse characterized by abnormal ﬂexion of the unconstrained proximal row, a fairly typical pattern of carpal malalignment, known as CIND-VISI (carpal instability nondissociative–volar intercalated segment instability) [32]. When axially loaded, the three proximal bones are not constrained equally by the palmar crossing midcarpal ligaments. Because of the peculiar arrangement of the distal ligaments crossing the midcarpal joint, the scaphoid is allowed larger rotation into ﬂexion and pronation than the lunate and triquetrum. Under axial load, the triquetrum is the one that ﬂexes the least, being so much constrained by the TqHC ligaments. If the palmar and dorsal scapholunate and LTq ligaments are intact, these diﬀerences in angular rotation are likely to generate increasing torques at both intercarpal levels, resulting in an increasing coaptation of these joints [31]. This increased intercarpal coaptation further contributes to the proximal carpal row stability. Accordingly, if the LTq ligaments have failed completely and the secondary stabilizers are not properly functional, the scaphoid and lunate tend to adopt an abnormal ﬂexed posture, whereas the triquetrum remains solidly linked to the distal row (Fig. 2) [33]; this is CID-VISI (carpal instability dissociative–volar intercalated segment instability). In both instances (CID-VISI secondary to LTq dysfunction and CIND-VISI secondary to rupture of the TqHC ligament), there is abnormal ﬂexion of lunate and scaphoid. In the CIND pattern, the triquetrum follows the abnormal ﬂexion tendency, whereas in the CID pattern, there is a dissociation between lunate and triquetrum [32].

Mechanisms of injury Most isolated injuries to the LTq ligaments appear as the consequence of a fall backward on the outstretched hand, the arm being externally rotated, the forearm supinated, and the wrist extended and radially deviated. In these circumstances, the impact concentrates on the hypothenar area, particularly on the pisiform, which acts as a punch against the extended triquetrum. This dorsally and proximally directed vector to the triquetrum induces its dorsal translation. The lunate does not follow the triquetrum; however, as it is eﬀectively constrained dorsally by the radius and palmarly by the antipronation long radiolunate ligament (Fig. 3). As a consequence, substantial shear stress occurs at the LTq joint, causing progressive stretching, and

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Fig. 2. When the intrinsic LTq ligaments and the extrinsic radiotriquetral ligament have failed, a carpal collapse appears, the so-called volar intercalated segment instability (VISI). As shown in a clinical case (A) and two schematic representations (B and C), lunate and scaphoid rotate abnormally into ﬂexion (curved arrows), whereas the unconstrained triquetrum may appear proximally translated (straight arrow).

ultimately tearing of the different LTq-stabilizing ligaments. Nonetheless, massive rupture of the strong palmar LTq ligament rarely occurs, unless there is a concomitant violent rotation of the distal row into further pronation, in which case the action of the palmar TqHC ligament adds the extra destabilizing force that is required for such a strong structure to fail. Supporting this explanation is the fact that the two ligaments (palmar LTq and TqHC) seldom both are disrupted. Injury to the LTq ligaments may appear associated to be with other local lesions. A frequent scenario involves the combination of a partial or complete rupture of the LTq ligaments, a peripheral tear of the triangular ﬁbrocartilage, and a distal avulsion of the ulnotriquetral ligament. The mechanism of production of these combined injuries may be similar to the mechanism discussed for the isolated LTq injury except for the presence of radial deviation and pronation as the predominant torque-inducing vectors. According to Melone and Nathan [34], this combination of injuries is not unusual and needs to be investigated thoroughly to avoid missing any of its components. In this respect, any avulsion fracture of the palmar rim of the

Fig. 3. Schematic representation in the sagittal (A) and transverse (B) planes of one of the most common mechanisms of production of LTq ligament disruption. The hypothenar eminence hits the ground inducing a dorsal translation of the pisiform and triquetrum (Tq). The lunate does not follow such displacement because it is strongly constrained by the radius dorsally and by the radiolunate ligaments (l) palmarly. The result shear stress may be sufﬁcient to provoke a massive disruption of the LTq ligaments.

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triquetrum, as documented by Smith and Murray [35], is to be interpreted as a subtle sign of a more extensive LTq injury. Another typical association of carpal injuries seems to result from a direct perilunate destabilization process, as postulated by Mayﬁeld [5]. In such instances, the wrist has undergone a violent extreme extension, associated with a variable degree of ulnar deviation and midcarpal supination, often owing to violent trauma, such as that sustained in falls from heights or in motorcycle accidents. In these instances, injury to the LTq ligaments occurs in stage III, following rupture of the scapholunate ligaments (stage I) and lunocapitate dislocation (stage II). If the scapholunate problem heals spontaneously or with intervention, and the LTq problem remains unresolved, symptoms from the ulnar-sided instability may predominate, requiring speciﬁc treatment. Although not of a traumatic origin, the LTq joint may become progressively unstable because of a long-standing ulnocarpal abutment [36]. In the presence of an ulna-plus variant, degeneration of the proximal membranous portion of the LTq joint by a wear mechanism is frequent and should never be confused with, or treated as if it were the result of, a traumatic event. Biomechanical eﬀects of rupture of the lunotriquetral supporting ligaments In the laboratory, several attempts to ascertain the consequences of LTq ligament disruptions have been made [11,12,21,22]. The ﬁrst published investigation of the role of the LTq ligaments in the carpal kinematics was by Reagan et al [7], who also were the ﬁrst to analyze a series of such ligament injuries. They showed that in patients with severe LTq sprains, there was often a static VISI deformity and abnormal motion of the carpus (Fig. 4). That clinical study also showed that on lateral x-rays the longitudinal axis of the triquetrum, which in normal subjects exhibits an average 16 ﬂexion relative to the longitudinal axis of the lunate, shows an extension posture of more than 14 in severe LTq disruption—a more than 30 change in the LTq angle compared with normal (see Fig. 2C). Reagan et al [7] also described an increased proximal migration of the triquetrum on ulnar-deviated posteroanterior radiographs. In 1990, Viegas et al [37] showed that even in partial disruptions of the LTq ligament there is increased motion between the elements of the LTq joint (Fig. 5), a ﬁnding later conﬁrmed by Horii et al [11] using biplanar radiography. All intercarpal joints have altered kinematics after complete LTq ligament sectioning. The changes were especially marked at the LTq joint, with the lunate adopting a palmar ﬂexed position and the triquetrum rotating into supination. Li et al [38] concluded that the palmar LTq ligament is the major stabilizer of the LTq joint during wrist extension and that the rest of the LTq ligament provides stability during ulnar deviation. Horii et al [11] and Viegas et al [37] emphasized the importance of the dorsal radiotriquetral and scaphotriquetral ligaments in the prevention of a global carpal collapse when the LTq ligaments are disrupted. In most studies, a carpal collapse, typically in the form of a VISI pattern, occurred only when the ligaments were sectioned in association with complete LTq ligament division. Li et al [38] did not observe a static or dynamic VISI deformity after sectioning only the LTq ligaments.

Fig. 4. In advanced stages of LTq dissociation with carpal collapse, abnormal kinematics is obvious: (A) In radial deviation, scaphoid and lunate are ﬂexed, whereas the triquetrum is in neutral alignment. There is no step-off at the LTq joint. (B) In ulnar deviation, neither the scaphoid nor the lunate rotates into extension but instead remains ﬂexed. The triquetrum, by contrast, migrates proximally (arrow), and an obvious step-off appears at the LTq joint.

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Fig. 5. A 32-year-old housewife whose ulnar-sided wrist pain did not resolve with physiotherapy and required surgery. Arthroscopy disclosed complete rupture of palmar and dorsal LTq ligaments despite normal carpal alignment. A dorsal approach to the ulnocarpal joint showed the lesion between the lunate (L) and triquetrum (Tq) and the abnormally increased mobility that occurred when the wrist from ulnar deviation (U.D.) (A) was rotated toward radial deviation (RD) (B). In the latter position, the triquetrum migrated distally, and a substantial capsular gap appeared (arrow).

More recently, Ritt et al [12], from the Mayo Clinic, reported on a series of cadaver specimens using stereoradiographic techniques to study carpal kinematics after different sequences of LTq ligament sectioning (Fig. 6). According to that investigation, neither the isolated section of the proximal LTq membrane nor the disruption of proximal and dorsal regions of the LTq capsule creates any signiﬁcant change in carpal alignment (stage 2 in Table 1) or carpal motion. From a kinematic viewpoint, partial tears of the proximal LTq membrane need not to be treated because they have minimal mechanical consequences. In contrast, when the palmar LTq ligament is

Fig. 6. Experimental setup used by the group at the Mayo Clinic to investigate carpal kinematics after sequential section of diﬀerent LTq supporting ligaments. (From Ritt MJPF, Linscheid RL, Cooney WP, Berger RA, An KN. The lunotriquetral joint: kinematic effects of sequential ligament sectioning, ligament repair, and arthrodesis. J Hand Surg Am 1998;23:432–45; with permission.)

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Table 1 Carpal alignment ( ) relative to the radius (changes from intact stage) at neutral wrist position* Axis of Rotation

Scaphoid Stage I Stage II Stage III Stage IV Stage V Lunate Stage I Stage II Stage III Stage IV Stage V Triquetrum Stage I Stage II Stage III Stage IV Stage V

X (+) Pronation (ÿ) Supination

Y (+) Flexion (ÿ) Extension

Z (+) Ulnar deviation (ÿ) Radial deviation

0.3 ÿ1.7 ÿ1.3 ÿ1.3 ÿ2.6

ÿ0.2 1.0 ÿ0.2 ÿ1.3 3.8

ÿ0.6 ÿ0.2 ÿ0.8 ÿ2.2 ÿ1.4

1.0 ÿ0.8 ÿ2.3 ÿ3.5 ÿ3.6

ÿ1.2 1.2 1.2 0.2 9.0

0.6 ÿ0.9 ÿ1.4 ÿ1.9 ÿ2.5

ÿ0.5 ÿ1.4 1.0 ÿ0.7 ÿ5.2

ÿ1.1 0.0 0.5 0.4 7.1

0.7 ÿ0.2 ÿ1.5 ÿ2.0 ÿ3.2

* Larger, bold numbers indicate statistically signiﬁcant from intact stage. Stage I, intact specimen; Stage II, section of the proximal and dorsal LTq ligaments; Stage III, complete section of all intrinsic LTq ligaments; Stage IV, section on LTq and dorsal radiotriquetral ligaments; Stage V, as in stage IV after cyclic loading. Modiﬁed from Ritt MJPF, Linscheid RL, Cooney WP, Berger RA, An KN. The lunotriquetral joint: kinematic effects of sequential ligament sectioning, ligament repair, and arthrodesis. J Hand Surg Am 1998;23:432–45.

sectioned selectively, signiﬁcant changes in carpal kinematics occur. Although the intrinsic tendency of the scapholunate complex to rotate into ﬂexion still is balanced (no carpal malalignment yet at this stage), increased LTq instability becomes evident, especially in ulnar deviation. Only after dividing the dorsal radiotriquetral and scaphotriquetral ligaments, carpal malalignment occurs in a consistent fashion: Lunate and triquetrum supinate, ﬂex, and radially deviate (stage 4 in Table 1). The strong dorsal radiotriquetral and scaphotriquetral ligaments can act as rotational constraints for the LTq joint in the absence of the dorsal LTq ligament. One factor that should be taken into account is the eﬀect of cyclic loading on the generation of abnormal patterns of motion. Horii et al [11] applied ‘‘some degree of manipulation’’ after sectioning of the ligaments. It may require secondary attenuation from prolonged cyclic loading to produce the clinical ﬁndings. Ritt et al [12] simulated gradual attenuation of the remaining ligaments by repetitively loading the joint before analyzing carpal motion. The values of static carpal malalignment changed dramatically: The static malalignment increased in magnitude (stage 5 in Table 1). Most laboratory attempts to explain the pathomechanics of one particular injury have an important drawback: The experiments cannot simulate what happens in living systems in which healing and remodeling have a great eﬀect on the end results. Nevertheless, from most of these cadaver studies, the results of which seem to be in accordance with the observations made in clinical practice, one can conclude that (1) injury to the proximal and dorsal LTq ligaments does not cause signiﬁcant alteration in carpal mechanics; (2) after division of all palmar and dorsal LTq ligaments, substantial kinematic dysfunction, suﬃcient to induce traumatic synovitis, may appear but not static deformity (dynamic VISI deformity arises only on cyclic loading); and (3) when the secondary LTq joint stabilizers (dorsal radiotriquetral and scaphotriquetral ligaments) are divided, a highly dysfunctional static VISI deformity arises. References [1] Berger RA, Imaeda T, Berglund L, An KN. Constraint and material properties of the subregions of the scapholunate interosseous ligament. J Hand Surg Am 1999;24:953–62.

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[2] Johnston RB, Seiler JG, Miller EJ, Drvaric DM. The intrinsic and extrinsic ligaments of the wrist: a correlation of collagen typing and histologic appearance. J Hand Surg Br 1995;20:750–4. [3] Ritt MJPF, Bishop AT, Berger RA, Linscheid RL, Berglund LJ, An KN. Lunotriquetral ligament properties: a comparison of three anatomic subregions. J Hand Surg Am 1998;23:425–31. [4] Viegas SF, Yamaguchi S, Boyd NL, Patterson RM. The dorsal ligaments of the wrist: anatomy, mechanical properties, and function. J Hand Surg Am 1999;24:456–68. [5] Mayﬁeld JK. Patterns of injury to carpal ligaments: a spectrum. Clin Orthop 1984;187:36–42. [6] Mayﬁeld JK, Johnson RP, Kilcoyne RF. The ligaments of the human wrist and their functional signiﬁcance. Anat Rec 1976;186:417–28. [7] Reagan DS, Linscheid RL, Dobyns JH. Lunotriquetral sprains. J Hand Surg Am 1984;9:502–14. [8] Osterman AL, Seidman GD. The role of arthroscopy in the treatment of lunatotriquetral ligament injuries. Hand Clin 1995;11:41–50. [9] Viegas SF, Patterson RM, Hokanson JA, Davis J. Wrist anatomy: incidence, distribution, and correlation of anatomic variations, tears, and arthrosis. J Hand Surg Am 1993;18:463–75. [10] Sennwald GR, Zdravkovic V, Oberlin C. The anatomy of the palmar scaphotriquetral ligament. J Bone Joint Surg Br 1994;76:146–9. [11] Horii E, Garcia-Elias M, An KN, et al. A kinematic study of luno-triquetral dissociations. J Hand Surg Am 1991; 16:355–62. [12] Ritt MJPF, Linscheid RL, Cooney WP, Berger RA, An KN. The lunotriquetral joint: kinematic effects of sequential ligament sectioning, ligament repair, and arthrodesis. J Hand Surg Am 1998;23:432–45. [13] Garcia-Elias M, Pita´goras T, Gilabert-Senar A. Relationship between joint laxity and radio-ulno-carpal joint morphology. J Hand Surg Br 2003;28:158–62. [14] Ritt MJPF, Stuart PR, Berglund LJ, Linscheid RL, Cooney WP, An KN. Rotational stability of the carpus relative to the forearm. J Hand Surg Am 1995;20:305–11. [15] Wiesner L, Rumelhart C, Pham E, Comtet JJ. Experimentally induced ulno-carpal instability: a study on 13 cadaver wrists. J Hand Surg Br 1996;21:24–9. [16] Ambrose L, Posner MA. Lunate-triquetral and midcarpal joint instability. Hand Clin 1992;8:653–68. [17] Feipel V, Rooze M. The capsular ligaments of the wrist. Eur J Morphol 1997;35:87–94. [18] Garcia-Elias M. Soft-tissue anatomy and relationships about the distal ulna. Hand Clin 1998;14:165–76. [19] Hogikyan JV, Louis DS. Embryologic development and variations in the anatomy of the ulnocarpal ligamentous complex. J Hand Surg Am 1992;17:719–23. [20] Lichtman DM, Noble WH III, Alexander CE. Dynamic triquetrolunate instability: case report. J Hand Surg Am 1984;9:185–8. [21] Lichtman DM, Schneider JR, Swafford AR, Mack GR. Ulnar midcarpal instability—clinical and laboratory analysis. J Hand Surg 1981;6:515–23. [22] Trumble TE, Bour CJ, Smith RJ, Glisson RR. Kinematics of the ulnar carpus related to the volar intercalated segment instability pattern. J Hand Surg Am 1990;15:384–92. [23] Weaver L, Tencer AF, Trumble TE. Tensions in the palmar ligaments of the wrist: I. the normal wrist. J Hand Surg Am 1994;19:464–74. [24] Mizuseki T, Ikuta Y. The dorsal carpal ligaments: their anatomy and function. J Hand Surg Br 1989;14:91–8. [25] Zancolli ER. Localized medial triquetral-hamate instability: anatomy and operative reconstruction-augmentation. Hand Clin 2001;17:83–96. [26] Kauer JMG. The mechanism of the carpal joint. Clin Orthop 1986;202:16–26. [27] Weber ER. Concepts governing the rotational shift of the intercalated segment of the carpus. Orthop Clin North Am 1984;15:193–207. [28] Seradge H, Sterbank PT, Seradge E, Owens W. Segmental motion of the proximal carpal row: their global effect on the wrist motion. J Hand Surg Am 1990;15:236–9. [29] Sennwald GR, Zdravkovic V, Kern HP, Jacob HAC. Kinematics of the wrist and its ligaments. J Hand Surg Am 1993;18:805–14. [30] Anatomy and Biomechanics Committee of the International Federation of Societies for Surgery of the Hand. Position statement: deﬁnition of carpal instability. J Hand Surg Am 1999;24:866–7. [31] Kobayashi M, Garcia-Elias M, Nagy L, et al. Axial loading induces rotation of the proximal carpal row bones around unique screw-displacement axes. J Biomech 1997;30:1165–7. [32] Garcia-Elias M. Kinetic analysis of carpal stability during grip. Hand Clin 1997;13:151–8. [33] Garcia-Elias M. What about injury of the lunotriquetral complex: treatment principles. Chir Main 2003;22:57–64. [34] Melone CP, Nathan R. Traumatic disruption of the triangular ﬁbrocartilage complex: pathoanatomy. Clin Orthop 1992;276:65–73. [35] Smith DK, Murray PM. Avulsion fractures of the volar aspect of triquetral bone of the wrist: a subtle sign of carpal ligament injury. AJR Am J Roentgenol 1996;166:609–14. [36] Palmer AK. Triangular ﬁbrocartilage complex lesions: a classiﬁcation. J Hand Surg Am 1989;14:594–606. [37] Viegas SF, Patterson RM, Peterson PD, et al. Ulnar-sided perilunate instability: an anatomic and biomechanic study. J Hand Surg Am 1990;15:268–78. [38] Li G, Rowen B, Tokunaga D, Ryu J, Kato H, Kihira M. Carpal kinematics of lunotriquetral dissociations. Biomed Sci Instrum 1991;27:273–81.

Atlas Hand Clin 9 (2004) 17–24

Lunotriquetral instability: clinical ﬁndings David M. Kalainov, MDa,b,*, Brian J. Hartigan, MDa,b, Mark S. Cohen, MDc,d a

Department of Orthopaedic Surgery, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA b Northwestern Center for Orthopedics, 676 North St. Clair, Suite 450, Chicago, IL 60611, USA c Hand and Elbow Program, Department of Orthopaedic Surgery, Rush–Presbyterian–St. Luke’s Medical Center, Chicago, IL, 60612, USA d Midwest Orthopaedics, 1725 West Harrison Street, Suite 1063, Chicago, IL 60612, USA

Isolated injuries of the lunotriquetral (LT) interosseous ligament are a well-recognized cause of ulnar-sided wrist pain. Distinguishing this injury from other causes of ulnar-sided wrist pain can be diﬃcult. The spectrum of LT ligament pathology ranges from partial tears with variable wrist pain and weakness to complete separation of the lunate and triquetrum with sag of the ulnar carpus. A thorough clinical examination with supportive imaging studies allows for an accurate diagnosis and provides information as to the extent of the injury.

Examination Patients with symptomatic LT interosseous ligament injuries typically describe wrist pain and swelling after an impact to the palmar surface of the hand. Swelling subsides within the ﬁrst few weeks after trauma. Episodic wrist pain may persist, however, localizing to the ulnar and dorsoulnar aspects of the joint. Other symptoms may include stiﬀness, a sensation of giving way, popping or clicking with motion, grip weakness, and paresthesia in the ulnar nerve distribution. Frequently the traumatic event is forgotten, and symptoms develop after gradual attenuation of the LT ligament and secondary capsular stabilizers (dorsal radiocarpal, dorsal intercarpal, and ulnar arcuate ligaments). In individuals with no history of trauma, LT instability may be the result of age-related attritional changes. Positive ulnar variance is associated with traumatic LT ligament injuries and may facilitate degenerative changes in the ligament complex from repeated axial loading. The evaluation begins with an assessment of the patient’s age, hand dominance, occupation, recreational activities, symptoms, mechanism of injury, time from injury, previous wrist or hand conditions, and past medical history. A thorough examination is important in determining other possible etiologies of ulnar-sided wrist discomfort (Box 1). The appearance of the skin is documented, and wrist range of motion and grip strength measurements are recorded. Comparative measurements are obtained from the contralateral, uninjured wrist. In stable or dynamically unstable LT ligament sprains, the wrist may appear normal. With dissociation of the LT interval and attenuation of the secondary joint restraints, an unstable static situation may result, leading to a supination deformity or ulnar sag of the carpus. The ulnar head appears dorsally prominent in this situation.

* Northwestern Center for Orthopedics, 676 North St. Clair, Suite 450, Chicago, IL 60611, USA. E-mail address: [email protected] (D.M. Kalainov). 1082-3131/04/$ - see front matter Ó 2004 Elsevier Inc. All rights reserved. doi:10.1016/S1082-3131(03)00076-1

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Box 1. Causes of ulnar-sided wrist pain LT ligament injury Triangular fibrocartilage tear Inflammatory or crystalline arthropathy Arthrosis distal radioulnar joint Arthrosis pisotriquetral joint Ulnar impaction syndrome Ulnar styloid impingement Distal radioulnar joint instability Midcarpal instability Kienbo¨ck’s disease Fracture Ulnar artery thrombosis Nerve entrapment Extensor carpi ulnaris subluxation Tendinitis Ganglion cyst Tumor Psychological

Fig. 1. LT ballottement test is performed by securing the pisotriquetral unit between the thumb and index ﬁnger of one hand and the lunate with the thumb and index ﬁnger of the other hand. Dorsal and volar stresses are applied across the LT interval. Pain, with or without crepitus and abnormal joint mobility, suggests ligamentous injury.

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Fig. 2. LT shear test is performed by using one thumb to apply a dorsal force to the pisotriquetral unit and the other thumb to apply a volar force to the lunate. Pain, with or without crepitus and increased joint laxity, represents a positive test.

Fig. 3. Gilula’s arcs—zero rotation posteroanterior wrist radiograph.

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Fig. 4. Posteroanterior wrist radiograph shows static LT instability. The triquetrum is translated proximally with a stepoﬀ in two of Gilula’s arcs.

Provocative tests are useful in conﬁrming the clinical diagnosis of an LT ligament injury. Finger pressure over the dorsal margin of the LT interval and palpation in the ‘‘ulnar snuﬀ box’’ will elicit pain. Ulnar deviation of the wrist with pronation and axial compression may demonstrate a painful clunk. The LT ballottement test (Fig. 1) and LT shear test (Fig. 2) will also reproduce the patient’s symptoms. Depending on the severity of the injury, these maneuvers may be accompanied by clicking or palpable motion across the LT interval. The examination also should include the radial aspect of the wrist, the midcarpal interval, and the contralateral wrist. Provocative testing of the contralateral wrist may show a similar degree of LT joint mobility; this suggests generalized ligamentous laxity, rather than a clinically signiﬁcant LT interval injury. An injection of a local anesthetic, with or without corticosteroid, into the radiocarpal or midcarpal space helps support the diagnosis of an LT ligament injury. A poor response to the injection suggests an extra-articular source of ulnar-sided wrist pain. Patients with isolated LT injuries also would be expected to experience temporary symptom improvement with wrist immobilization.

Imaging Plain radiographs are recommended in the initial evaluation of a suspected LT ligament injury. A lateral view and an unstressed posteroanterior view in zero rotation are obtained for measurements of carpal bone alignment and ulnar length. On the posteroanterior image of a normal wrist, the proximal and distal joint surfaces of the proximal carpal row and the proximal

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Fig. 5. Lateral wrist radiograph shows static LT instability and a volar ﬂexion intercalated segment instability deformity. The longitudinal axis of the triquetrum is deﬁned as a line passing through the distal triquetral angle and bisecting the proximal articular surface (solid line). The longitudinal axis of the lunate is deﬁned as a line passing perpendicular to the distal margins of the lunate and bisecting the proximal articular surface (dashed line). The longitudinal axis of the scaphoid is deﬁned as a line bisecting the proximal and distal scaphoid articular surfaces (dotted line). The scapholunate angle in this example measures 15 , and the LT angle measures 5 .

joint surfaces of the distal carpal row create smoothly curved arcs as described by Gilula (Fig. 3). An injury to the LT ligament alone is not readily identiﬁed on the posteroanterior projection; static radiographs are normal in most cases. With the disruption of the LT ligament and secondary capsular restraints, separation of the triquetrum from the lunate is created with proximal translation of the triquetrum or LT overlap. Occasionally the posteroanterior radiograph may show a break in Gilula’s arcs outlining the proximal carpal row, with a step-off at the LT interval (Fig. 4). Comparative images of the contralateral wrist are necessary to distinguish a normal variation in carpal alignment from pathologic alignment. The lateral radiograph helps to verify an injury to the LT ligament and secondary capsular restraints. In a normal wrist and in the case of an isolated LT ligament injury with an intact wrist capsule, the lateral scapholunate angle measures on average 47 (range 30–60 ), and the lateral LT angle measures on average 14 (range 31 to ÿ3 ). The LT angle often is diﬃcult to measure accurately and reliably. Combined loss of the LT ligament and secondary ligamentous restraints leads to volar ﬂexion of the lunate (and scaphoid) and diminished scapholunate and LT angles (Fig. 5). When viewed on a lateral radiograph, the static injury pattern is representative of volar ﬂexion intercalated segment instability. Dynamic LT instability is more challenging to assess radiographically but may be detected by alterations in the LT interval on posteroanterior stress views in radial and ulnar deviation. Evaluation of the wrist under ﬂuoroscopy may assist in showing dynamic LT instability when it is not apparent on stress radiographs. Fluoroscopy can be done in the oﬃce with use of a miniﬂuoroscopy unit. Carpal bone alignment is examined during active and passive wrist motion and during provocative testing of the LT interval. Abnormal mobility of the LT joint and proximal translation of the triquetrum indicate a destabilizing injury. The clinician always should compare the injured side with the normal side. The role of MRI in the evaluation of LT ligament injuries is evolving. To visualize interosseous ligaments optimally, a high ﬁeld strength magnet (1.5 Tesla), a dedicated wrist coil, and thin image slices are recommended. A tear in the proximal membranous portion of the LT ligament usually is detected; the thicker dorsal and palmar regions of the LT ligament and the

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Fig. 6. Wrist arthrogram. A contrast agent was injected into the radiocarpal interval. The arthrogram shows a defect in the LT ligament with dye accumulating in the LT interspace and midcarpal joint (arrow).

Fig. 7. Axial T1-weighted MRI. The study was enhanced with injection of intra-articular gadolinium into the radiocarpal joint. A defect in the LT ligament is shown with dye traversing the LT interval into the midcarpal space (arrow).

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Fig. 8. LT instability as viewed arthroscopically from the midcarpal space. A probe is positioned easily into the gap between the lunate and triquetrum.

capsular ligaments are visualized poorly. The clinical signiﬁcance of a positive MRI result is diﬃcult to determine because the membranous portion of the LT ligament has little role in carpal stability. MRI has the advantage of providing diagnostic information for other conditions, however, that may cause ulnar-sided wrist pain, including ganglia, soft tissue tumors, osteonecrosis, and triangular ﬁbrocartilage complex tears. Wrist arthrograms are obtained less commonly owing to advances in MRI technology. Most investigators have favored a three-compartment evaluation with injection of contrast material into the radiocarpal, midcarpal, and distal radioulnar joints. Leakage of contrast material across the LT interspace signiﬁes a defect in the LT ligament (Fig. 6). This ﬁnding does not distinguish a small tear from a large tear, and it does not deﬁne the exact location of the ligament defect. A 20% incidence of LT contrast media leaks has been reported in arthrograms of asymptomatic individuals between the ages of 20 and 60 years. Contrast-enhanced MRI with intra-articular gadolinium is an improvement over standard arthrograms, providing more detailed visualization of surrounding bone and soft tissue structures (Fig. 7). Bone scintigraphy is useful in cases in which wrist radiographs are normal but the clinical examination is suspicious for an LT interval injury. Increased isotope uptake in the region of the LT interspace denotes heightened bone metabolic activity or reactive synovitis. Although the speciﬁcity for detecting an LT ligament injury is low, a negative scan can be useful in excluding this area of the wrist as a source of pain. Tomograms and CT studies are not helpful in evaluating LT ligament injuries, but they may aid in deﬁning other pathology, such as occult carpal bone fractures and osteochondral injuries. Diagnostic arthroscopy provides the examiner with the best imaging of the LT ligament. Although only the central portion of the ligament complex can be seen clearly, valuable information is garnered by probing the LT interspace from the radiocarpal and the midcarpal perspectives (Fig. 8). In addition, the stability of other intercarpal intervals, the status of joint cartilage, and the integrity of the triangular ﬁbrocartilage complex can be assessed accurately.

Summary A thorough history and physical examination provide suﬃcient information to suspect an LT ligament injury. Plain radiographs are helpful in reﬁning the diagnosis. Wrist radiographs

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appear normal, however, in most cases. Ulnar-positive variance commonly is associated with disruption of the LT ligament complex. Dynamic LT instability may be detected by stress radiographs or by examination of the wrist under ﬂuoroscopy. Static LT instability is much rarer and is evidenced by a break in Gilula’s arcs and a volar ﬂexion intercalated segment instability deformity on standard posteroanterior and lateral wrist views. MRI, arthrography, and bone scintigraphy can aid in the evaluation, but the results of these studies need to be correlated with the physical examination and plain radiographs. Arthroscopy provides the best means for assessing the integrity of the LT ligament and surrounding carpal structures.

Further readings Blazar PE, Lawton JN. Diagnosis of acute carpal ligament injuries. In: Trumble TE, editor. Carpal fracture-dislocations: Monograph series 21. Rosemont: American Academy of Orthopaedic Surgeons; 2002. p. 19–26. Butterﬁeld WL, Joshi A, Lichtman D. Lunotriquetral injuries. J Am Soc Surg Hand 2002;2:195–203. Cohen MS. Ligamentous injuries and instability patterns. In: Light TR, editor. American Society for Surgery of the Hand: hand surgery update 2. Rosemont: American Academy of Orthopaedic Surgeons; 1999. p. 97–106. Geissler WB, Freeland AE, Savoie FH, et al. Intracarpal soft-tissue lesions associated with an intra-articular fracture of the distal end of the radius. J Bone Joint Surg Am 1996;78:357–65. Gilula LA, Weeks PM. Post-traumatic ligamentous instabilities of the wrist. Radiology 1978;129:641–51. Horii E, Garcia-Elias M, An KN, et al. A kinematic study of luno-triquetral dissociations. J Hand Surg Am 1991;16: 355–62. Kirschenbaum D, Sieler S, Solonick D, et al. Arthrography of the wrist: assessment of the integrity of the ligaments in young asymptomatic adults. J Bone Joint Surg Am 1995;77:1207–9. Reagan DS, Linscheid RL, Dobyns JH. Lunotriquetral sprains. J Hand Surg Am 1984;9:502–14. Shin AY, Battaglia MJ, Bishop AT. Lunotriquetral instability: diagnosis and treatment. J Am Acad Orthop Surg 2000;8: 170–9. Watson HK, Weinzweig J. Physical examination of the wrist. Hand Clin 1997;13:17–34. Wright TW, Del Charco M, Wheeler D. Incidence of ligament lesions and associated degenerative changes in the elderly wrist. J Hand Surg 1994;19:313–8. Yang Z, Mann FA, Gilula LA, et al. Scaphopisocapitate alignment: criterion to establish a neutral lateral view of the wrist. Radiology 1997;205:865–9.

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The role of wrist arthroscopy in the diagnosis and treatment of lunotriquetral joint injuries Gregory J. Hanker, MD University of Southern California, Hand and Upper Extremity Surgery, Southern California Orthopedic Institute, 6815 Noble Avenue, Van Nuys, CA 91405, USA

An injury of the lunotriquetral ligament (LTL) and associated dysfunction of the lunotriquetral joint (LTJ) can be a common cause of ulnar-sided wrist pain. The carpal instability that develops from this ligamentous injury can pose a signiﬁcant problem in regard to accurate diagnosis and subsequent appropriate therapeutic intervention. Wrist arthroscopy plays a critically important role in assessing ulnar-sided wrist pain in general and LTJ injuries in particular. This article describes the current approach to the diagnosis and treatment of LTJ injuries and the related use of wrist arthroscopy as the most important extension of our clinical examination, imaging studies, and therapeutic surgical tools.

Lunotriquetral joint instability Carpal instability (CI) has been a recognized clinical entity for well over a century. During the last 30–40 years, speciﬁc patterns of ligamentous injuries have been described; the pathomechanics of these injuries have been actively investigated [1–10]. Classiﬁcation schemes have evolved in conjunction with improved understanding of these instability patterns [11]. The Mayo Classiﬁcation of Carpal Instability provides a comprehensive categorization of the spectrum of injuries that are known to occur; dividing the patterns of CI into dissociative (CID), nondissociative (CIND), and combined or complex (CIC). CI is the end result of a wrist ligamentous injury that may occur from a variety of mechanisms of injury. The failure of wrist ligaments and their resultant instability pattern not only causes pain, but produces abnormal carpal kinetics and joint kinematics. A wrist joint thus should be considered clinically unstable when: (1) it exhibits a symptomatic dysfunction, (2) it is not able to bear loads (ie, the transference of functional loads causes sudden changes in stress on the articular cartilage), and (3) it does not exhibit normal movement during any portion of its arc of motion (ie, the carpals do not maintain motion throughout their range without sudden alteration of intercarpal alignment) [12]. The degree of instability can vary from a subtle micromovement caused by ligament attenuation, to displacement with a wide gap. In the literature on CI, there exists varied terminology describing instability. In addition to the Mayo Classiﬁcation of CID, CIND, and CIC, some investigators like to classify CI into four major clinical types: dorsiﬂexion instability (DISI), palmar ﬂexion instability (VISI), midcarpal instability, and ulnar translocation. CIs also can be referred to as static or dynamic. A static CI is characterized by a ﬁxed dissociation between carpals that is clearly evident on imaging studies or arthroscopy. A dynamic CI is characterized by normal routine radiographs, abnormal kinematics on stress imaging, or altered kinetics and kinematics viewed during arthroscopy [13].

E-mail address: [email protected] 1082-3131/04/$ - see front matter Ó 2004 Elsevier Inc. All rights reserved. doi:10.1016/S1082-3131(03)00077-3

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Pathoanatomy and pathomechanics The wrist is an extremely complex joint [14]. Its osseous and ligamentous anatomy is well known [15–17]. There are intrinsic ligaments with insertion entirely within the carpal bones, and extrinsic ligaments with insertion on the carpals and wrist structures outside of the carpus. The LTL is the intrinsic, interosseous ligament that stabilizes the lunate to the triquetrum (ie, the LTJ). The LTJ is the ulnar portion of the proximal carpal row (PCR), which consists of the scaphoid, lunate, and triquetrum. The PCR acts as an intercalated segment (IS), providing a mechanical linkage between the distal radius and ulna and the distal carpal row. There are three distinct regions of the LTL (Fig. 1). The dorsal and palmar portions are thickened and provide a strong, stable connection at the LTJ. The palmar portion of the LTL is the thickest and strongest of the three regions, and is the most important in the transmission of load and strain from the triquetrum to the lunate. The central, proximal portion of the LTL consists of a ﬁbrocartilaginous membrane that provides minimal joint stability [18]. Additional secondary constraints to the ulnar aspect of the PCR are the intrinsic midcarpal ligaments, the triquetrohamate (THL), and the triquetrocapitate (TCL) ligaments, the extrinsic ligaments located palmarly, the ulnolunate (ULL) and the ulnotriquetral (UTL) ligaments, and dorsally, the dorsal radiocarpal (DRC) or radiotriquetral ligament and the dorsal intercarpal (DIC) or scaphotriquetral ligament. With an injury to the LTL, the normal kinetics and kinematics of the wrist are disturbed [19]. A spectrum of LTJ injuries can develop, ranging from a mild sprain with or without dynamic instability to a complete dislocation with CID and a static carpal instability often referred to as volar intercalated segment instability (VISI). The mechanism of LTL tearing causing injury to the LTJ is somewhat controversial [13]. Perilunate and reverse perilunate injury patterns, dorsally or palmarly applied forces, fractures of the distal radius or carpals, degenerative wear

Fig. 1. (A). Appearance of normal LTL and LTJ viewed from the 6U portal. Note that this portal allows for complete observation of the palmar, central, and dorsal portions of the LTL. (B) Dorsal portion of LTL is probed. The fraying of the dorsal LTL is consistent with a chronic grade 0 injury. (C) Only from the 6U portal can the entire palmar portion of the LTL be observed and probed for possible injury.

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from ulnar impaction, and inﬂammatory arthritis have all been implicated. It is believed that when the LTL is torn partially or completely, a subtle micromotion instability ensues, which causes wrist joint synovitis and usually chondromalacia [18]. Damage to the intrinsic, interosseous LTL alone is usually not sufﬁcient to cause LTJ dissociation and a grossly unstable VISI. Additional tearing of the secondary constraints to the LTJ is necessary to produce a static CI (Fig. 2). Signiﬁcant injury to the ulnocarpal ligamentous complex (ULL, UTL) or the dorsal extrinsic ligaments (DRC, DIC) then results in a VISI. Secondary attenuation from prolonged cyclic loading also may play an important role [18,19]. Clinical presentation and imaging The diﬀerential diagnosis of ulnar-sided wrist pain is staggering [20]. Extrinsic wrist disorders and internal wrist derangements must be taken into account during the patient history and thorough physical examination. A typical patient with an LTL injury usually presents a history of signiﬁcant trauma to the hand and wrist. Symptoms may be acute or chronic. The ulnar-sided wrist pain is intermittent to frequent and is worsened with activities, especially those wrist movements that require rotation and ulnar deviation. Wrist motion produces clicking or a clunk. The wrist feels stiff and the grip is weak. The physical examination usually does not reveal a palmar deformity characteristic of a VISI, but often shows decreased range of motion, clicking, or a clunk with movement, especially painful ulnar deviation or rotation. There is often tenderness to palpation dorsally at the LTJ region or directly ulnarly over the carpus. Provocative tests that stress the LTJ and reveal pain, crepitus, or joint laxity are suggestive of a ligament injury. Standard plain posteroanterior and lateral radiographs should be obtained on every patient with a suspected LTJ injury. Typically these radiographs are normal, but they might assist with the diﬀerential diagnosis of other wrist injuries known to cause ulnar-sided wrist pain. The plain radiographs can be scrutinized for hints of an LTJ instability, such as disruptions of Gilula’s lines, a relative malalignment between the lunate and capitate, or possibly a static collapse with a VISI pattern of triquetral extension and lunate ﬂexion. A gap or diastasis between lunate and triquetrum is virtually never observed. Some investigators have advocated wrist motion or stress radiographic studies, cineradiography, three-compartment wrist arthrography, nuclear bone scans, computed tomography, and MRI [21]. In the author’s practice, the author routinely obtains posteroanterior, lateral, and oblique radiographs of the wrist, and in those select patients in whom the diagnosis of wrist pain is still indeterminate, the author orders an MRI that is taken on a high resolution 1.5 Tesla magnet and read by an experienced musculoskeletal radiologist. Even though the MRI scan is neither sensitive nor speciﬁc for an LTL tear, it may shed additional information about other associated wrist joint injuries.

Fig. 2. Complete tear of the extrinsic UTL and moderate sprain with hemorrhage of the adjacent ULL.

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Role of wrist arthroscopy The arthroscopic examination of the painful wrist, especially in the evaluation of LTJ injuries, has become the deﬁnitive modality of diagnostic investigation. Wrist arthroscopy is an essential component of a thorough examination, because it provides the only direct means of inspecting the integrity of the LTL, the stability of the LTJ, and the presence of associated wrist joint pathology. Subtle LTJ instabilities that were not diagnosed with previously described imaging modalities now can be discovered accurately by way of arthroscopy. Wrist arthroscopy of the radiocarpal joint (RCJ) and the midcarpal joint (MCJ) is now the gold standard in the diagnosis of CI based on its superior accuracy in the direct evaluation of ligamentous injuries [13,20–29].

Technique The diagnostic wrist arthroscopy begins with a systematic and thorough examination of the RCJ by way of dorsoradial (3,4) portal, dorsoulnar (4,5, or 6R) portal, and ulnar (6U) portal. Use of a probe is essential to palpate the internal wrist structures, especially the intrinsic and extrinsic ligaments. The LTL and LTJ are diﬃcult to visualize with the arthroscope in the dorsoradial portal. These ulnar-sided structures are better observed through the dorsoulnar portal with the probe in the ulnar portal. Through the dorsoulnar portal, the dorsal and membranous portions of the LTL are clearly observed; the volar portion of the LTL can be palpated with the probe. The ulnocarpal ligaments (ULL and UTL) are clearly seen, as is the entire triangular ﬁbrocartilage complex (TFCC) and the cartilaginous surfaces of the entire PCR. The volar portion of the LTL is best visualized through the ulnar (6U) portal, where it can be seen in its entirety (see Fig. 1C). Associated injuries to the TFCC, extrinsic ligaments, cartilage, and capsule can be assessed with RCJ arthroscopy, using a combination of these three portals. To complete the arthroscopic evaluation of LTJ injury, it is essential to establish midcarpal portals [30]. The midcarpal radial (MCR) portal is the best vantage point to observe the LTJ. Because the LTL does not extend distally into the MCJ, the interval between the lunate and triquetrum can be seen clearly and instability of the LTJ can be assessed accurately. A probe placed into the midcarpal ulnar (MCU) portal or triquetrohamate (TH) portal then can be used to assess dynamic or static instability. This instability assessment is further enhanced by stress loading the LTJ. The degree of LTJ instability can be graded arthroscopically with the Geissler classiﬁcation [31]. In the author’s experience, the Geissler grade I interosseous ligament injury really consists of three separate and distinct patterns of intrinsic ligament damage. In the ﬁrst, the LTL can show evidence of hemorrhage but no attenuation or laxity of its ﬁbers that would be consistent with a dynamic instability. When a mild sprain of the LTL occurs, hemorrhage of the ligament can be visualized arthroscopically, but as long as the ﬁbers of the ligament have not been stretched beyond their plastic limit of elongation, the basic integrity of the LTL is maintained. The LTJ is stable. This pattern of mild sprain heals in an uneventful fashion. The author recommends that this injury pattern be considered a grade 0. The second pattern of Geissler grade I injury consists of attenuation of the LTL such that its ﬁbers are sprained or stretched beyond their plastic limit, and the basic integrity of the ligament is compromised. Arthroscopically, the LTL seems lax, loose, or wavy; but it remains intact. When palpated by the intra-articular probe, the ﬁbers resist any passage of the probe. In the acute stage of injury, the attenuated LTL has the potential to produce laxity or an early stage of instability that could be considered predynamic in the sense that further instability develops with time and additional joint loading. The author thus suggests that a Geissler grade I interosseous ligament injury is a mild to slight sprain of the LTL with arthroscopically observable attenuation or laxity of the LTL, no disruption of the ligamentous ﬁbers such that a probe can be passed through the ligament, and the potential predynamic or dynamic instability of the LTJ as evidenced by excessive LTJ movement (ie, altered kinematics) or early chondromalacia at the joint line (ie, altered kinetics).

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The third pattern of injury consists of LTL attenuation and complete tearing of the membranous portion of the LTL. The LTJ typically shows more dynamic instability as excessive abnormal carpal movement is seen in the midcarpal space and often in the RCJ also; there is usually much more scar tissue built up in the ulnar aspect of the RCJ adjacent to the LTJ. Often excessive synovitis is seen in the RCJ and MCJ. A diastasis of the LTJ is not seen, and there is no static instability. This pattern corresponds to a moderate ligamentous sprain and should be considered a grade II interosseous ligament injury. In a Geissler grade III injury of the LTL, the LTL is completely torn. The LTJ is dynamically unstable and the probe can be passed through the LTJ. A static instability is not present in that the LTJ can be reduced with simple manipulation of the lunate and triquetrum. A VISI deformity is not present. The arthroscope cannot be passed through the LTJ, because the gap caused by the instability is not suﬃcient to allow this to occur. A Geissler grade IV injury results from a complete disruption of the LTL with a stressinduced diastasis of the LTJ such that the arthroscope can be passed easily through the wide gap between lunate and triquetrum. The secondary ligamentous constraints (ie, the extrinsic ligaments) are injured; a CID pattern (ie, VISI) is present. The author therefore recommends a revision of the Geissler classiﬁcation (Table 1). This arthroscopic classiﬁcation of wrist interosseous ligament instability is most useful for the CID pattern of PCR instability. It is especially germane for fully understanding the extent of LTL injury and resultant LTJ instability. And as shown in the next section, the arthroscopic classiﬁcation assists with the choice of appropriate therapeutic intervention and prognosis for outcome. Arthroscopic evaluation of the sprained wrist provides the treating physician with the unique capability to examine the full extent of the internal pathologic process directly. A thorough visual examination of the RCJ and MCJ directly deﬁnes the nature and extent of not only the ligamentous injury, but also signiﬁcant associated osseous, cartilaginous, and ﬁbrocartilaginous injuries [32]. In the ulnar aspect of the RCJ, it is common to ﬁnd a signiﬁcant buildup of dorsal capsular scar tissue that forms from the original traumatic injury to the LTJ (Fig. 3). This scar tissue must be de´brided to fully visualize the three regions of the LTL: the proximal cartilaginous surfaces of the lunate and triquetrum, the TFCC, and the ulnocarpal ligaments (ULL and UTL). If the LTJ instability is chronic, it is important to assess the ulnar aspect of the carpus for signs of ulnar impaction syndrome (UIS). If degeneration of the TFCC or cartilage is present, consideration should be given to formally treat the UIS, augmenting treatment of the LTJ instability [33]. The diagnostic role of arthroscopy in the MCJ is to search out additional cartilaginous and ligamentous pathology [34]. Degeneration of the cartilage on the proximal poles of the capitate and hamate and the distal articular surfaces of the lunate and triquetrum may be present. LTJ instability may occur in conjunction with midcarpal instability [35]. MCJ arthroscopy allows for examination of the intrinsic ligaments of the MCJ, especially the THL and TCL. If the

Table 1 Geissler classiﬁcation modiﬁcation Grade

Arthroscopic ﬁndings

0

Hemorrhage of interosseous ligament seen in RCJ. No attenuation. No incongruency of carpal alignment in MCJ. Attenuation of interosseous ligament seen in RCJ. No full substance ligament tear. No joint incongruency, but increased movement or chondral degeneration at the joint articular faces seen in the MCJ. In addition to attenuation of the interosseous ligament, the central membranous portion is completely torn. The probe can be passed through the central tear. There is possibly dynamic instability as evidenced by excessive joint movement at the MCJ. Usually excessive scar tissue build up and synovitis is seen in RCJ and possibly in MCJ. Interosseous ligament is completely torn. Joint is dynamically unstable. Probe can be easily passed through the joint, but a wide diastasis is not present. The joint is reducible. No static instability. Gross instability. Marked joint incongruency with static instability. Arthroscope passes through the gap between carpals.

I II

III IV

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Fig. 3. (A) A signiﬁcant amount of scar tissue develops in the dorsoulnar aspect of the RCJ in association with a tear of the LTL. (B) Arthroscopic debridement is necessary to clean out the scar tissue. (C) Following debridement, the intraarticular structures about the ulnar aspect of the RCJ can now be seen, probed, and evaluated for injury.

midcarpal ligaments have been injured, the degree of instability can be assessed and classiﬁed as previously described. The arthroscopic ﬁndings of MCJ arthritis or instability thus enable the treating physician to alter his or her therapeutic intervention. Without the beneﬁcial role of arthroscopy, we would have no reliable nonsurgical diagnostic modality to assist with classiﬁcation of the CI or to aide in the discovery of ancillary pathology that would deﬁnitely alter the treatment plan.

Treatment of lunotriquetral joint injuries Wrist arthroscopy plays the critical role of focusing attention on the nature and extent of the LTJ instability and the presence of associated pathology. This allows one to better plan appropriate therapeutic intervention. The initial procedure of therapeutic surgical intervention should be a preliminary diagnostic wrist arthroscopy to conﬁrm the suspected diagnosis and allow one to proceed with the most appropriate surgical technique. Beyond this, the treatment of LTJ instability becomes controversial. There are several factors that should be taken into account, however, when planning therapeutic intervention: the elapsed period of time between injury and initiation of treatment (ie, acute versus chronic injuries) and whether or not the pattern of CI is dynamic and reducible or static and ﬁxed into a VISI pattern. We have seen that the presence of associated injuries to the ulnar-sided wrist joint, especially the presence of degenerative cartilage changes, signiﬁcantly alters surgical options. Finally, the desires of the patient must be taken into account. A patient may not want to undergo an operation with a low likelihood of success or one with signiﬁcant risk and complications, or an operation with a long period of convalescence and rehabilitation. Permanent wrist stiﬀness associated with carpal fusions may not be appealing to some patients.

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Fig. 4. Grade 0 sprain of LTL. Mild hemorrhage is seen in the central membranous portion of the ligament. In the background, note sprains of the ulnocarpal extrinsic ligaments. The UTL is to the left, and it reveals a mild sprain of the ﬁbers with hemorrhage but no attenuation of its ﬁbers. The ULL is to the right, and it reveals a moderate sprain with attenuation of its ﬁbers.

In an attempt to minimize the surgical trauma of an open wrist operation and to speed up the rehabilitation process, the treatment of LTJ instability by arthroscopic technique has been investigated recently [20–29,32]. The techniques of arthroscopic ligament debridement and arthroscopic reduction of LTJ injury and internal ﬁxation with K-wires (ARIF) is described later, as is their usefulness and success compared with other recommended open surgical techniques. In the past, treatment of stable LTJ acute and chronic injuries was a period of splint or cast immobilization in conjunction with other supportive conservative measures [2]. Currently it is believed that only minor, acute LTL sprains respond to rest and immobilization. It is highly unlikely that this approach will work successfully for any serious acute or chronic LTJ instability. If symptoms do not improve within 6 weeks, if the clinical examination is consistent with a moderate or severe sprain of the LTL or if a wrist MRI scan reveals a serious LTJ injury, or if chronic LTJ instability is already present, then arthroscopy should be performed [20–22,24,25,28,29]. The degree of LTL damage, LTJ instability (dynamic or static), and the

Fig. 5. Grade I sprain of LTL. There is hemorrhage of the ligament and minimal attenuation of its ﬁbers.

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Fig. 6. (A) Grade II membranous tear of LTL. Minimal ligamentous attenuation is present. (B) Probe passes through central tear.

presence of associated wrist joint pathology determines whether or not to proceed with ARIF or an open surgical technique. Direct ligament repair, ligament reconstruction with autogenous tendon graft, LTJ arthrodesis, midcarpal arthrodesis, proximal row carpectomy, and total wrist fusion are the open surgical procedures that have been advocated to restore LTJ alignment and thus the integrity of the PCR as a stable IS. Several investigators have recommended direct ligament repair for an acute injury whenever suﬃcient LTL remains [2,21,23,36,37]. The LTL is reattached to the triquetrum, as this is the usual site of avulsion. The repair technique is surgically demanding and may require dorsal and palmar approaches. Augmentation of the LTL repair with a dorsal capsulodesis to improve the extrinsic ligament support has been suggested to be of some beneﬁt [38]. The results of direct LTL repair to restore stability of the LTJ have been satisfactory, with the Mayo Clinic reporting an 86% success rate [23]. In patients with chronic LTJ instability, static instability with VISI, or the arthroscopic or open surgical ﬁnding of a non-repairable LTL, several investigators have recommended LTL reconstruction with autogenous tendon graft [2,23,37]. On the other hand, other investigators have argued that they prefer an LTJ arthrodesis over a tendon graft reconstruction. The technique of LTL reconstruction using a distally based strip of extensor or ﬂexor carpi ulnaris is an extremely demanding surgical procedure and may require signiﬁcant surgical exposure by way of dorsal and palmar arthrotomies. Advocates of the reconstruction argue that it preserves LTJ motion and near normal carpal kinematics, as opposed to LTJ arthrodesis in which there is signiﬁcant loss of wrist motion. Only a small group of patients have undergone reconstruction, but the Mayo Clinic group has reported good success [2,23]. LTJ arthrodesis is a technically less demanding surgical procedure than reconstruction and has been shown by several investigators to be successful at reducing or eliminating wrist pain and improving function [20,38–41]. It has been reported to have a high rate of LTJ nonunion, however, and mild to slight associated stiffness in wrist mobility [42,43]. In several comparative studies of LTJ arthrodesis versus reconstruction or repair, the later groups achieved superior results in regard to patient satisfaction, postoperative complications, and necessity for reoperation [21,23]. It should be pointed out that in patients with a ﬁxed VISI deformity, it is also necessary to consider reconstruction of the palmar ulnocarpal ligaments or the dorsal extrinsic ligaments to prevent rotation of the PCR into a VISI [23,39,43]. In some wrists, it may even be necessary to proceed to a midcarpal arthrodesis (ie, lunate-triquetrum-hamate or lunate-triquetrum-hamatecapitate) if restoration of PCR alignment cannot be achieved [20,44]. Ligamentous repair, reconstruction, or joint arthrodesis needs to take into account the presence of degenerative cartilaginous changes or ﬁndings of UIS with degeneration of the TFCC and ulnar cartilage [20–23]. Ulnar shortening osteoplasty also may be needed. As an added beneﬁt from an ulna shortening, it has been shown that the procedure partially stabilizes the ulnar aspect of the wrist through an increased tension in the ulnocarpal ligament complex

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Fig. 7. (A) Moderately severe grade II LTL tear displaying a complete tear of the central membranous portion and partial tearing of the dorsal and palmar portions. (B) The torn LTL ﬂap is de´brided. The arthroscope is in the 6U portal and the suction punch is in the 6U portal. Use of the ulnar portal greatly facilitates access to the LTL. (C) De´brided LTL and LTJ viewed from the ulnar portal. Note that from the ulnar portal, the palmar portion of the LTL is better visualized. (D) LTJ anatomically reduced and pinned, as viewed from 6U portal. (E) MCU portal view of LTJ before pinning. Note the minimal gap associated with this dynamic but reducible instability. (F) Midcarpal view of LTJ reduced and stabilized with percutaneous K-wires.

[45]. Arthroscopically, a debridement of the degenerative TFCC lesion can be performed. In selected cases, an arthroscopic Wafer procedure might be feasible in place of an ulnar shortening osteotomy.

Author’s preferred treatment Acute LTL injuries that have not responded to conservative care after 6 weeks of treatment, and certainly by 3 months, should be evaluated arthroscopically. Likewise, if an MRI has been obtained and it is suggestive or diagnostic of an ulnar-sided internal derangement, proceed to arthroscopy. The wrist arthroscopy provides valuable information unobtainable by way of any

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Fig. 8. Radiofrequency probe debriding membranous tear of LTL and performing thermal shrinkage.

other diagnostic or imaging source. Arthroscopy of the RCJ and MCJ allows for a thorough evaluation of the LTL and the extent of LTJ instability using the Geissler classiﬁcation of wrist interosseous ligament instability or the modiﬁed classiﬁcation scheme that the author has proposed. The author’s classiﬁcation scheme provides a helpful guide to choosing an appropriate therapeutic technique. A grade 0 LTJ instability is a stable ligamentous injury that should be expected to heal with wrist immobilization (Fig. 4). The prognosis for successful resolution of the wrist pain associated with the mild to slight sprain is excellent. A grade I LTJ instability reveals an intact LTL without tearing, but there is attenuation of the ﬁbers and some degree of increased carpal movement between lunate and triquetrum (Fig. 5). The LTJ is congruent, but altered carpal kinetics may be apparent if chondromalacia is noted at the LTJ interface viewed in the MCJ. This speciﬁc injury pattern has not been addressed adequately in the literature. Treatment options would include further wrist joint immobilization, ligamentous shrinkage using a radiofrequency probe, LTJ percutaneous K-wire pinning for 8 weeks, or a combination of ligamentous shrinkage, K-wire pinning, and immobilization. A grade II LTJ instability is characterized by a complete tear of the central membranous portion of the LTL (Fig. 6) and signiﬁcant attenuation or partial tearing of the palmar or dorsal portions of the LTL (Fig. 7). A mild dynamic instability characterized by excessive LTJ motion is seen when stress is applied to the joint. This injury pattern has the potential to lead to progression of cartilage degeneration, synovitis, and chronic pain. An arthroscopic debridement of the torn LTL ﬂap should be done to eliminate any mechanical source of joint irritability. Several studies suggest that a debridement of the ﬂap tear alone produces satisfactory outcomes [24,25,28,29]. Only one small study contradicted this ﬁnding [26]. Some investigators also suggest reduction of the LTJ and percutaneous K-wire pinning for approximately 8 weeks [20,24,27,46,47]. Electrothermal ligamentous shrinkage can be performed with either a radiofrequency probe or a laser [48,49]. This new technology can be applied to an attenuated LTL or even the ulnocarpal extrinsic ligaments (Fig. 8). Frequently an excessive amount of dorsal capsular scar tissue is present in the dorsoulnar section of the RCJ. This scar tissue inhibits full visualization of the ulnar-sided wrist structures, and it should be arthroscopically de´brided (see Fig. 3). A grade III LTL injury reveals a complete tear of the LTL (Fig. 9). The LTJ is clearly unstable when a force is applied, but the joint is anatomically reducible. An LTJ diastasis is not present, and injury to the secondary restraint extrinsic ligaments is not seen. The author recently reviewed a series of 33 such patients who were treated with arthroscopic debridement of the torn LTL, arthroscopic reduction of the LTJ, and percutaneous K-wire ﬁxation for 8–10 weeks. Using the modiﬁed Mayo Wrist Score to assess outcome, the author found that 55% of the patients had a good or excellent result. Eighty percent of the patients, however, had virtually no wrist pain. The lower scores producing fair results were caused by persistent wrist stiffness or

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Fig. 9. (A) Complete tear of LTL with grade III instability—dynamic and reducible. Viewed from 6U portal of RCJ. (B) LTJ viewed from MCR portal. Dynamic instability with excessive movement at joint line but no gap. (C) Torn LTL de´brided and an elevator instrument introduced through the ulnar portal. The dynamic instability is reduced by placing the elevator under the lunate and reducing the step-off at the LTJ. (D) MCR view showing the LTJ reduced. (E) Technique of ARIF. Percutaneous K-wires are placed across the reduced LTJ viewing arthroscopically and ﬂuoroscopically. (F) Radiographs after ARIF.

grip weakness. Of the 33 patients, 20 developed LTJ grade III instability secondary to a displaced intra-articular distal radius fracture. The remaining 13 patients injured their wrists secondary to an acute sprain. Those patients with LTJ instability resulting from a distal radius fracture all scored satisfactory with arthroscopic treatment. The poorest outcomes occurred in those patients with wrist sprains that were treated 6 months or more after their injury. A suitable alternative to the previously described arthroscopic treatment is to proceed to an open repair of the torn LTL as long as the ligament seems arthroscopically viable. An LTL reconstruction or an LTJ arthrodesis is an alternative, but the author does not favor either procedure unless the arthroscopic treatment failed or the ligament was not viable for repair. The literature also reports satisfactory results with debridement of the torn LTL or debridement combined with pinning of the LTJ. These studies do not clearly sort out grade II from grade III ligament

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Fig. 10. Grade IV LTJ instability. Note the ‘‘drive-through’’ sign as the arthroscope can be maneuvered into the wide diastasis between the lunate and the triquetrum. The proximal pole of the capitate in the MCJ is visible in the background.

injuries, however, and may even contain a few grade IV patterns. Also, confusing terminology such as ‘‘partial’’ ligament tear and ‘‘complete’’ ligament tear is used to describe a broad category of ligamentous injuries. This makes interpretation of the results difﬁcult. An alternative arthroscopic surgical procedure would be a ligament plication of the ulnocarpal ligaments and pinning of the LTJ. Early results with this technique of arthroscopic plication have been promising [50]. Chronic grade III LTL injury, that is, injury more than 6 months old, will not likely do well with arthroscopic treatment alone. Direct repair, reconstruction, or LTJ arthrodesis would be better treatment options. If a direct repair of the LTL is possible, the author highly favors this technique. The author has no personal experience with tendon reconstruction, but the results in the literature are favorable. The author has had good success with the LTJ arthrodesis. Acute grade IV LTL injuries present with severe alteration of carpal alignment, incongruency of the LTJ, and gross instability (Fig. 10). It is possible to manage these arthroscopically before ﬁxed VISI occurs. If the LTJ is arthroscopically reducible, it may be pinned. The triquetrum also should be pinned to the hamate to maintain its anatomic alignment between the distal radius and ulna and the distal carpal row. This should allow for healing of the extrinsic ligaments, because they will be torn. Cast and pin immobilization should continue for a minimum of 8 weeks. A chronic grade IV LTL injury is beyond arthroscopic management. The ﬁxed rigidity of the CI and the high association of TFCC injuries with possible secondary cartilage degenerative disease limit reconstructive surgical options. A ﬁxed, irreducible LTJ instability is best managed with an intercarpal arthrodesis, such as a lunate-triquetral-capitate-hamate fusion, which then stabilizes the PCR to the distal row. If the chronic instability is still reducible, ligament reconstruction or LTJ arthrodesis in conjunction with a dorsoulnar capsulodesis may be of beneﬁt. The usefulness of arthroscopy in the treatment of chronic instability is to assess the wrist joint for associated pathology. The ﬁndings of cartilage degeneration, SLL injury, and SLJ instability, MCJ ligamentous injury and midcarpal instability, TFCC injury, and UIS with positive ulnar variance signiﬁcantly aﬀect the choice of therapeutic surgical alternative procedures.

Summary The role of wrist arthroscopy in the treatment of LTL injury and LTJ instabilities is diagnostic and therapeutic. Diagnostic arthroscopy of the RCJ and MCJ is the most essential

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tool to accurately assess the extent of the injury and to classify the grade of interosseous ligament instability. It also aides in the discovery of any associated pathology that would change the choice of surgical alternatives. Based on these arthroscopic ﬁndings, treatment can be appropriately planned. Even though the therapeutic surgical options for treatment of LTJ instability remain somewhat controversial, the technique of arthroscopic reduction of LTJ instability with percutaneous K-wire ﬁxation (ARIF) is a viable alternative for the acute, modiﬁed grade I, II, and select grade III injuries. The feasibility and practicality of ARIF should be weighed against established success of ligament repair, ligament reconstruction, or LTJ arthrodesis.

References [1] Linscheid RL, Dobyns JH, Beabout JW, et al. Traumatic instability of the wrist. Diagnosis, classiﬁcation and pathomechanics. J Bone Joint Surg 1972;54A:1612–32. [2] Reagan DA, Linsheid RL, Dobyns JH. Lunotriquetral sprains. J Hand Surg 1984;9A:502–14. [3] Mayﬁeld JK, Johnson RP, Kilcoyne RK. Pathomechanics and progressive perilunar instability. J Hand Surg 1980; 5A:226–41. [4] Lichtman DM, Schneider JR, Swafford AR, et al. Ulnar midcarpal instability: clinical and laboratory analysis. J Hand Surg 1981;6A:515–23. [5] Lichtman DM, Noble WH III, Alexander CE. Dynamic triquetrolunate instability: case report. J Hand Surg 1984; 9A:185–8. [6] Talaisnik J, Malerich M, Prietto M. Palmar carpal instability secondary to dislocation of scaphoid and lunate: report of case and review of the literature. J Hand Surg 1982;7A:606–12. [7] Weber ER. Wrist mechanics and its association with ligamentous instability. In: Lichtman D, editor. The wrist and its disorders. Philadelphia: WB Saunders; 1988. [8] Trumble TE, Bour CJ, Smith RJ, et al. Kinematics of the ulnar carpus related to the volar intercalated segment instability pattern. J Hand Surg 1990;15A:384–92. [9] Viegas SF, Patterson RM, Peterson PD, et al. Ulnar-sided perilunate instability: an anatomic and biomechanic study. J Hand Surg 1990;15A:268–78. [10] Horii E, Garcia-Elias M, An KN, et al. A kinematic study of luno-triquetral dissociations. J Hand Surg 1991;16A: 355–62. [11] Dobyns JH, Cooney WP. Classiﬁcation of carpal instability. In: Cooney W, Linscheid R, Dobyns J, editors. The wrist—diagnosis and operative treatment. St. Louis: Mosby; 1998. [12] The Anatomy and Biomechanics Committee of the International Federation of Societies for Surgery of the Hand. Deﬁnition of carpal instability [position statement]. J Hand Surg 1999;24A:866–7. [13] Bednar JM, Osterman AL. Carpal instability: evaluation and treatment. J Am Acad Orthop Surg 1993;1:10–7. [14] Patterson RM, Nicodemus CL, Viegas SF. High-speed, three-dimensional kinematic analysis of the normal wrist. J Hand Surg 1998;23A:446–53. [15] Berger RA. General anatomy. In: Lichtman D, Alexander A, editors. The wrist—diagnosis and operative treatment. St. Louis: Mosby; 1998. [16] Garcia-Elias M, Dobyns JH. Bones and joints. In: Cooney W, Linscheid R, Dobyns J, editors. The wrist—diagnosis and operative treatment. St. Louis: Mosby; 1998. [17] Berger RA. Ligament anatomy. In: The wrist—diagnosis and operative treatment. St. Louis: Mosby; 1998. [18] Ritt MJ, Bishop AT, Berger RA, et al. Lunotriquetral ligament properties: a comparison of three anatomic subregions. J Hand Surg 1998;23A:425–31. [19] Ritt MJ, Linsheid RL, Cooney WP, et al. The lunotriquetral joint: kinematic effects of sequential ligament sectioning, ligament repair, and arthrodesis. J Hand Surg 1998;23A:432–45. [20] Butterﬁeld WL, Joshi AB, Lichtman DM. Lunotriquetral injuries. J Am Soc Hand Surg 2002;2(4):195–203. [21] Shin AY, Battaglia MJ, Bishop AT. Lunotriquetral instability: diagnosis and treatment. J Am Acad Orthop Surg 2000;8:170–9. [22] Cooney WP, Berger RA. Interosseous ligamentous injuries of the wrist. In: McGinty J, editor. Operative arthroscopy. 3rd edition. Philadelphia: Lippincott, Williams and Wilkins; 2003. [23] Bishop AT, Reagan DA. Lunotriquetral sprains. In: Cooney W, Linscheid R, Dobyns J, editors. The wrist— diagnosis and operative treatment. St. Louis: Mosby; 1998. [24] Ritter MR, Chang DS, Ruch DS. The role of arthroscopy in the treatment of lunotriquetral ligament injuries. Hand Clin 1999;15(3):445–54. [25] Ruch DS, Bowling J. Arthroscopic assessment of carpal instability. Arthroscopy 1998;14(7):675–81. [26] Westkaemper JG, Mitsionis G, Giannakopoulos PN. Wrist arthroscopy for the treatment of ligament and triangular ﬁbrocartilage complex injuries. Arthroscopy 1998;14(5):479–83. [27] Osterman AL, Seidman GD. The role of arthroscopy in the treatment of lunotriquetral ligament injuries. Hand Clin 1995;11(1):41–50. [28] Ruch DS, Poehling GG. Arthroscopic management of partial scapholunate and lunotriquetral injuries of the wrist. J Hand Surg 1996;21A:412–7.

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[29] Weiss AP, Sachar K, Glowacki KA. Arthroscopic debridement alone for intercarpal ligament tears. J Hand Surg 1997;22A:344–9. [30] Hofmeister EP, Dao KD, Glowacki KA, et al. The role of midcarpal arthroscopy in the diagnosis of disorders of the wrist. J Hand Surg 2001;26A:407–14. [31] Geissler WB, Freeland A, Savoie FH III, et al. Intraarticular soft-tissue lesions associated with an intraarticular fracture of the distal end of the radius. J Bone Joint Surg 1996;78A:357–65. [32] Gupta R, Bozentka DJ, Osterman AL. Wrist arthroscopy: principles and clinical applications. J Am Acad Orthop Surg 2001;9:200–9. [33] Hanker GJ. Arthroscopic management of ulnar impaction syndrome. In: Ruch D, editor. Techniques in wrist arthroscopy. New York: Springer-Verlag; 2003. [34] Dautel G, Merle M. Chondral lesions of the midcarpal joint. Arthroscopy 1997;13:97–102. [35] Lichtman DM, Culp RW, Joshi A. Palmar midcarpal instability. In: Operative arthroscopy. 3rd edition. Philadelphia: Lippincott, Williams and Wilkins; 2003. [36] Palmer AK, Dobyns JH, Linsheid RL. Management of post-traumatic instability of the wrist secondary to ligament rupture. J Hand Surg 1978;3A:507–32. [37] Shin A, Weinstein L, Berger R, et al. Treatment of isolated injuries of the lunotriquetral ligament. J Bone Joint Surg 2001;83B:1023–8. [38] Watson HK, Black DM. Instabilities of the wrist. Hand Clin 1987;3:103–11. [39] Guidera PM, Watson HK, Dwyer TA, et al. Lunotriquetral arthrodesis using cancellous bone graft. J Hand Surg 2001;26A:422–36. [40] Kirschenbaum D, Coyle M, Leddy J. Chronic lunotriquetral instability: diagnosis and treatment. J Hand Surg 1993; 18A:1107–12. [41] Pin P, Young V, Gilula L, et al. Management of chronic lunotriquetral ligament tears. J Hand Surg 1989;14A: 77–83. [42] Nelson D, Manske P, Pruitt D, et al. Lunotriquetral arthrodesis. J Hand Surg 1993;18A:1113–20. [43] Sennwald GR, Fischer M, Mondi P. Lunotriquetral arthrodesis. A controversial procedure. J Hand Surg 1995;2B: 755–60. [44] Trumble T, Bour C, Smith R, et al. Intercarpal arthrodesis for static and dynamic volar intercalated segment instability. J Hand Surg 1988;13A:384–90. [45] Smith B, Short W, Werner F, et al. The effect of ulnar shortening on lunotriquetral motion and instability: a biomechanical study. Presented at the American Society for Surgery of the Hand, Annual Fellow and Residents Meeting, 1994. [46] Alexander CE, Lichtman DM. Triquetrolunate instability. In: The wrist and its disorders. 2nd edition. Philadelphia: WB Saunders; 1997. [47] Whipple TL. Intrinsic ligaments and carpal instability. In: Arthroscopic surgery: the wrist. Philadelphia: JB Lippincott; 1992. [48] Sweet A, Weiss L. Applications of electrothermal shrinkage in wrist arthroscopy. Atlas Hand Clin 2001;6(2):203–10. [49] Frostick SP. Thermal capsulorrhaphy: basic science. In: McGinty J, editor. Operative arthroscopy. 3rd edition. Philadelphia: Lippincott, Williams and Wilkins; 2003. [50] Moskal MJ, Savoie FH III, Field LD. Arthroscopic capsulodesis of the lunotriquetral joint. Clin Sports Med 2001; 20(1):141–53.

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Combined lunotriquetral and triangular ﬁbrocartilage complex ligamentous injuries William B. Geissler, MD Department of Orthopaedic Surgery and Rehabilitation, Division of Hand and Upper Extremity Surgery, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 39216, USA

Arthroscopy has revolutionized the practice of orthopaedics, providing the technical capability to examine and treat intra-articular abnormalities directly. The wrist is a labyrinth of eight carpal bones, multiple articular surfaces with combined intrinsic and extrinsic ligaments, and a triangular ﬁbrocartilage complex (TFC), all within a 5-cm interval. This perplexing joint continues to challenge clinicians with an array of potential diagnoses and treatments. Wrist arthroscopy allows direct visualization of the cartilage surfaces, synovial tissue, and ligaments under bright light and magniﬁed conditions. Although most acute sprains of the wrist with normal radiographs resolve after temporary immobilization, how to further evaluate the patient who does not have improvement after such treatment is controversial. Tricompartmental wrist arthrography historically has been the gold standard for the detection of interosseous ligament tears and peripheral tears of the TFC complex [1]. The introduction of MRI of the wrist has markedly improved the detection of peripheral tears of the TFC complex, particularly in cases in which synovitis forms over the area of the peripheral tear of the articular disk where it occurs, possibly blocking the ﬂow of dye through the peripheral tear [2]. MRI has been less helpful in detecting injuries to the lunotriquetral interosseous ligament. The proven ability of wrist arthroscopy to detect and simultaneously treat wrist injuries has improved markedly the management of these injuries [3]. The TFC complex is a complex soft tissue support system that stabilizes the ulnar side of the wrist. It acts as an extension of the articular surface of the radius to support the proximal carpal row and also stabilizes the distal radioulnar joint. In 1989, Palmar proposed a classiﬁcation system for tears of the TFC complex that basically divided these injuries into two categories: traumatic (Class I) and degenerative (Class II) [4]. In Palmer’s classiﬁcation of traumatic Type I tears, the articular disk may tear centrally, at its radial or ulnar periphery, or at its distal attachment to the carpus. Malone noted that a peripheral tear of the articular disk is not an isolated event, but rather the principle constitutes of a multicomponent injury in close proximity to the ulnar styloid [5]. He noted that a spectrum of injury involving the TFC complex might occur. The soft tissue damage frequently has included the extensor carpi ulnar tendon sheath and in more severe cases has involvement of the ulnar carpal, lunotriquetral interosseous ligament, triquetral capitate, and triquetral hamate ligaments. This article reviews the indication for wrist arthroscopy and the management of complex injury involving the TFC complex as it extends and involves the lunotriquetral interosseous ligament.

E-mail address: [email protected] 1082-3131/04/$ - see front matter Ó 2004 Elsevier Inc. All rights reserved. doi:10.1016/j.ahc.2003.12.002

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Triangular ﬁbrocartilage complex The TFC complex is interposed between the proximal carpal row and the distal end of the ulna. This much studied structure remains poorly understood. As classically described by Palmar, it is composed of the ﬁbrocartilage articular disk, the volar and dorsal radioulnar ligaments, and the ﬂoor of the extensor carpi ulnaris tendon sheath [6]. In a coronal section, the central disk is generally wedge-shaped and radially inserts on to the articular surface of the radius by merging with hylan cartilage of the sigmoid notch and the lunate facet. Chidgey evaluated the collagen structure of the TFC and attempted to correlate this with biomechanic function. They found the radial side of the articular disk ﬁbrocartilage has thick collagen projecting 1–2 mm into the disk. The central portion of the articular disk has an oblique wave pattern for strength, compression, and tension, and the ulnar aspect of the articular disk has two main bundles: one directed to the ulnar styloid and one to the fovea. Proximal limbs of the palmar and dorsal radioulnar ligaments conjoin and insert into the fovea just medial to the pole of the distal ulna. These are referred to as ligamentum subcutaneum. The distal superﬁcial portion of the volar and dorsal radioulnar ligaments insert directly into the base of the ulnar styloid and are independent of the function of the ligamentum subcutaneum insertion. The exact function of the superﬁcial and deep components of the volar and dorsal radioulnar ligaments are controversial and have been studied by several investigators. The articular disk is a load-bearing structure. Its peripheral attachment is almost 5 mm thick and becomes thinner at the center, narrowing to less than 2 mm. It is the central portion that accepts most of the compressive loads transmitted from the carpus to the ulna. The thickness of this portion of the articular disk varies from individual to individual, with an inverse relationship between the TFC thickness and ulnar variance. The arterial anatomy of the TFC complex also has been studied. Thiru et al evaluated 12 cadaveric specimens with latex injections and determined three main supplies to the TFC complex. The ulnar artery supplies most of the blood to the TFC complex supporting the ulnar portion through dorsal and palmar radiocarpal branches. Histologic examination of the TFC complex found vessels ﬁlled with latex dye in the outer 15%–20%. Similarly, Bednar et al examined 10 cadavers with an India ink injection technique and found penetration of vessels from the periphery of 10%–40%. The importance of the articular disk in axial load bearing has been deﬁned clearly by Palmer and Warner [4]. In the static state, 82% of the axial compressive load of power grasp was transmitted from to the forearm through the radial carpal joint. Approximately 18% is supported by the articular disk and the ulna. When the disk is excised, load bearing by the ulna drops to approximately 5% of the total. Adams and Holly have shown that the peak strain was localized to the radial aspect of the articular disk and was maximized in loaded forearm pronation. The strain primarily originates about the coronal axis. These ﬁndings explain the prevalence of radial-sided injuries to the TFC with compression, such as a fall on an outstretched hand. The ulnar carpal ligaments are composed of the ulnar lunate and ulnotriquetral ligament. The disk carpal ligaments (disk-lunate and disk-triquetral) are components of what Garcia Elias and Domenenech-Mateu have termed ulnar carpal volar ligaments. These ligaments are the primary stabilizers for the relationship between the ulnar and palmar carpus. The origin was clearly shown by embryologic studies to be along the palmar margin of the TFC: they insert independently on to the lunate and triquetrum, with an additional insertion into the lunotriquetral interosseous ligament. Dorsally, the TFC complex has attachments to the ulnar carpus through the sheath of the extensor carpi ulnaris. The dorsal limbus is also the site of attachment for ﬁbers of the dorsal radioulnar ligament. The ﬁnal component of the TFC complex is the ulnar carpal meniscal homolog. There is controversy as to its function and existence. It is a layer of ﬁbrous connective tissue, variable in presentation, reaching maximum thickness in the presence of a lunula and sensory ossicle with full developed meniscal homolog. The prestyloid recess is typically present between the bony ulnar styloid and thickening of the ulnar soft tissues known as the meniscal homolog.

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Lunotriquetral interosseous ligament The lunate and triquetrum is constrained by two interosseous ligaments performed by stout transverse ﬁbers connecting the palmar and dorsal aspects of the two bones. Between the two, a ﬁbrocartilage membrane closes the joint proximally. Unlike the scapholunate interosseous ligament, the palmar lunotriquetral ligament is stronger than the dorsal one. The average yield strength of the palmar portion of the lunotriquetral ligament was 301 newtons as compared with 121 newtons, respectively. The proximal ﬁbrocartilage membrane is weakest and reported to be 64 newtons in average strength. The ﬁbers of the two interosseous lunotriquetral interosseous ligaments (volar and dorsal) are tauter in all ranges of motion than those of the scapholunate interosseous ligaments, suggesting a closer kinematic relationship. Symptomatic wrist conditions resulting from progressive disruption from the lunotriquetral interosseous ligament complex and the TFC complex result from traumatic and degenerative etiologies. Typically a patient who sustains injury to the lunotriquetral interosseous ligament sustains a fall, resulting in a hyperﬂexion injury to the wrist. Peripheral tears of the TFC complex generally are the result of twisting injuries. Malone reviewed the surgical pathology in 42 cases of traumatic TFC complex disruption and found a spectrum of injury resulting in ﬁve basic stages of increased instability [5]. In all cases, detachment of the articular disk from its ulnar insertion was the principle cause of distal radioulnar joint instability. The most common pathologic feature of all injuries and the hallmark of Stage I is detachment of the articular disk from its insertion at the base of the ulnar styloid. He noted that because disruption of the disk was virtually impossible without some damage to the adjoining dorsal and volar radioulnar ligaments, partial peripheral detachment of these ligaments also was considered a component of Stage I. Stage II is characterized by concomitant disruption of the adjacent infra-retinacular ECU sheath, resulting in subluxation or dislocation of the unrestrained tendon. Stage III injuries include damage to the volar ulnar carpal ligaments. In Stage IV injuries, there is partial or complete rupture of the lunotriquetral interosseous ligament with resultant lunotriquetral instability. Stage V injuries comprise the midcarpal joint because of disruption of the triquetral-capitate, triquetral-hamate ligaments. Malone postulated that a multidimensional force is prone to disrupt the articular disk and adjoining ECU sheath and with increasing energy, transverses a pathway across the ulnar carpal and lunotriquetral joints, causing serial rupture of these structures. In a sequential fashion, disruption of key soft tissues then would result in distal radioulnar joint, ECU, ulnar UCJ, and lunotriquetral joint instability. He noted that such a theory was clearly speculative and required further biomechanic collaboration. The key component in all these stages, however, is the initial peripheral disruption of the articular disk and the spectrum of injury that radiates from the base of the ulnar styloid. This is similar to the pathologic events demonstrated by Mayﬁeld as causing progressive perilunate instability.

History and physical examination Lunotriquetral instability may present with a spectrum of clinical conditions ranging from asymptomatic partial tears to painful complete disassociation with static collapse. Some patients describe a painful crepitation with ulnar deviation of the wrist. Symptomatic injuries exhibit point tenderness directly over the lunotriquetral interval and, with peripheral tears, the TFC complex over the prestyloid recess. Pain usually is aggravated with ulnar deviation and supination. Patients with peripheral tears to the articular disk of the TFC complex frequently hurt right at the prestyloid recess. This pain may be accentuated by hyper pronation and supination of the wrist. Generally patients with more central tears to the articular disk hurt directly over the head of the ulna. They complain of pain with forced ulnar deviation of the wrist. When there is extensor peripheral tearing to the articular disk with potential attenuation and progression distally into the ulnar side of the carpus, dorsal subluxation of the ulnar head in relation to the radius may be seen, particularly when comparing to the opposite wrist, with both wrists in ﬂexion.

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Diagnosis Reagan described the ballottement test, in which the lunate is stabilized ﬁrmly with the thumb and index ﬁnger with one hand while the triquetrum pisiform is displaced dorsally and palmarly with the opposite hand. A positive result elicits pain, crepitus, and excess displacement of the joint as compared with the opposite side. Kleinman described a shear test, which is a modiﬁcation of the ballottement test. By stabilizing the dorsal aspect of the lunate just beyond the medial edge of the distal radius, the pisiform is loaded in a dorsal direction, creating a shear force at the lunotriquetral interval that may cause pain. Chistodou described the Derby test. This involves loading dorsally the pisiform while the patient rotates the wrist along the ‘‘dart throwing’’ plane (from extension-radial deviation to ﬂexion-ulnar deviation). This provokes reduction of the subluxed lunotriquetral joint with which the feeling of instability disappears and grip strength increases, as long as pressure along the pisiform is maintained. Ambrosia described the ulnar snuﬀbox test. This involves applying a lateral pressure over the medial aspect of the triquetrum, just palmar to the extensor carpi ulnaris, while the wrist is deviated radially. This reproduces the patient’s symptoms. An injury of the lunotriquetral ligament or an ulnar styloid-triquetrum impingement syndrome should be in the diﬀerential. When this test is positive, a TFC complex problem is less likely, and one may be able to diﬀerentiate a combined injury from an isolated injury. It is important to note, however, that all these provocative maneuvers may be sensitive but poorly speciﬁc for lunotriquetral instability. Standard radiographs usually seem normal in most patients with recent dynamic instability. Occasionally a slight narrowing of the lunotriquetral joint with subchondral cyst formation may be seen in chronic dynamic instabilities. Only when there is complete division or attenuation of the intrinsic and extrinsic lunotriquetral supporting ligaments does it result in a static VISI pattern of malalignment. Arthrography may demonstrate a communication of dye between the radiocarpal and midcarpal joints [7]. This communication, however, may indicate a traumatic injury or chronic age-related perforation of the ﬁbrocartilaginous membrane. Wrist arthroscopy is a sensitive and accurate modality to evaluate the patient with ulnar-sided wrist pain [8]. The key to arthroscopic management of carpal instability and TFC complex tears is recognition of what is normal and what is pathologic anatomy. The radiocarpal and midcarpal spaces must be evaluated arthroscopically when carpal instability is suspected. Wrist arthroscopy is not complete if the midcarpal space is not evaluated with consideration of carpal instability. When the interosseous ligament tears, it hangs down and blocks visualization with the arthroscope in the radiocarpal space. The degree of rotation in the carpal bones and any abnormal motion are best appreciated from the unobstructed view available in the midcarpal space. The scapholunate and lunotriquetral interosseous ligaments should have a concave appearance as seen from the radiocarpal space (Fig. 1). The lunotriquetral interosseous ligament is best visualized with the arthroscope in the 4-5 or 6-R portal because of its oblique relationship in the proximal carpal row (Fig. 2). It is not visualized easily with the arthroscope in the 3-4 portal, particularly in petite wrists. In the midcarpal space, the lunotriquetral interval should be congruent, but occasionally there is a 1-mm step-off, as seen from the midcarpal space, which is normal (Fig. 3). There is normally slight motion between the lunate and triquetrum. A spectrum of injury to the lunotriquetral interosseous ligament is possible. The interosseous ligament seems to attenuate and then tear. Geissler devised an arthroscopic classiﬁcation of carpal instability [9]. In Grade I injuries there is loss of the normal concave appearance between the carpal bones and interosseous ligament bulges with a convex appearance (Fig. 4). Evaluation of the midcarpal space shows the carpal bones to be congruent. In Grade II injuries, the interosseous ligament becomes convex as in Grade I injuries, but the carpal bones are no longer congruent in the midcarpal space. There is increased motion between the lunotriquetral interval as seen in the midcarpal space (Fig. 5). In Grade III injuries, the interosseous ligament starts to separate and a gap is seen between the carpal bones from the radial carpal and the midcarpal space (Fig. 6). A 1-mm probe may be passed through the gap between the involved carpal bones from the carpal to the radial carpal space. In Grade IV injuries, there is complete detachment of the interosseous ligament. A 2.7-

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Fig. 1. Arthroscopic view of the normal concave appearance between the scaphoid and the lunate as seen with the arthroscope on the 3-4 portal.

mm arthroscope may be passed freely from the midcarpal space to the radial carpal space (Fig. 7). Geissler deﬁned this as the ‘‘drive-through sign.’’ Arthroscopic evaluation for tears of the articular disk of the TFC complex is best accomplished with the arthroscope in the 3-4 portal. A probe is brought in through the 6-R or 45 portal to palpate tension to the articular disk. Cooney described the trampoline sign, in which the tension to the articular disk is palpated. When there is loss of tension, the disk has a sunken appearance and is soft when palpated with a probe. A peripheral tear of the articular disk then should be suspected [10]. Frequently, when a peripheral tear exists, hypertrophic synovitis is

Fig. 2. Arthroscopic view of the normal concave appearance between the lunate and triquetrum as seen with the arthroscope in the 6-R portal.

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Fig. 3. Arthroscopic view of the normal congruent relationship between the lunate and triquetrum as seen from the midcarpal row with the arthroscope in the radial midcarpal portal.

Fig. 4. Arthroscopic view of a Geissler Type I rear to the interosseous ligament as seen from the radiocarpal space. The ligament is no longer concave and has become convex in appearance as it has stretched.

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Fig. 5. Arthroscopic view of a Geissler Type II tear of the lunotriquetral interosseous ligament as seen with the arthroscope in the radial midcarpal portal. The lunotriquetral interosseous ligament was convex as seen in the radiocarpal portal, and the lunate and triquetrum are no longer congruent in the midcarpal space with increased play between the carpals.

seen along the junction of the articular disk to the capsule. This may obscure the peripheral tear. Usually a shaver is brought in through the 6-R portal to debride the synovitis, revealing the peripheral tear [11]. The prestyloid recess is the area dorsal to the ulnar triquetral ligament and volar to the meniscal homolog. This is a normal recess and should not be confused with a peripheral tear of the articular disk [12]. A peripheral tear to the articular disk usually lies along

Fig. 6. Arthroscopic view of a Geissler Type III interosseous ligament tear between the lunate and triquetrum as seen from the radiocarpal space. A gap is seen between the two bones and an arthroscopic probe may be inserted between the carpals. A portion of the ligament is still attached between the bones.

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Fig. 7. Arthroscopic view of a Geissler Type IV interosseous ligament tear. The 2.7-mm arthroscope may be driven (drive-through sign) through the gap between the carpals.

the dorsal margin and not volarly, where the prestyloid recess lies [13]. Similarly, if the arthroscope is placed in the 6-R portal and advanced volarly at the level of the prestyloid recess, the pisiform may be seen. This is a normal recess and can be seen approximately 60% of the time. That the pisiform may be seen with the arthroscope in the 6-R portal is not abnormal and does not indicate a pathologic anatomy to the ulnar side of the wrist.

Management The management of acute and chronic ulnar-sided wrist injuries varies signiﬁcantly. As in most orthopaedic injuries, the prognosis for acute repair and reconstruction has a better result than the management of chronic injuries. In the patient with acute ulnar-sided wrist pain with normal radiographs, the management is controversial. In a patient with acute ulnar-sided wrist pain, normal radiographs, and tenderness over the periphery of the TFC and lunotriquetral interval, immobilization is the rule of thumb. The patient is re-examined at 2-week intervals and continues to be immobilized if demonstrating continued tenderness. Further modalities then are initiated if the patient continues to be symptomatic at 6 weeks. If the patient continues to be symptomatic at 6 weeks, MRI may be performed. MRI is particularly sensitive for detection of tears of the TFC complex, although less sensitive for lunotriquetral interosseous ligament injuries. The other option (which is favored by the author) would be to proceed with arthroscopic evaluation to the wrist. Wrist arthroscopy has been shown clearly to be the most sensitive adjunct in the detection of interosseous ligament injuries. As shown by Whipple, there is a window of opportunity for arthroscopic management of acute interosseous ligament tears [14]. Whipple has shown that management of acute interosseous ligament tears by arthroscopic reduction and pinning has a better prognosis than chronic injuries of longer than 3 months’ duration, because of the intrinsic ability of the interosseous ligament to heal itself.

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Arthroscopic technique The wrist is suspended with 10 pounds of traction in a traction tower. The volar arm and forearm are well padded with towels so that no portion of the skin comes in contact with the traction tower. The skin only is excised with the tip of a #11 blade at the 3-4 portal. If a tear of the TFC complex is suspected, inﬂow is provided through a needle in the 1-2 portal. This keeps the inﬂow out of the way during a potential arthroscopic TFC complex repair. This skin and capsule is spread with a hemostat and the 2.7-mm arthroscope with a blunt trocar is place in the 3-4 portal. The area carpal space is evaluated from radial to ulnar. A needle is used to identify the exact location of the 6-R portal as viewed intra-articularly, and skin is excised and the portal is made. Integrity of the articular disk and the periphery of the TFC is evaluated. Again, if any synovitis is noted about the periphery of the articular disk and it is soft to palpation, this is arthroscopically removed to evaluate for a peripheral tear (Fig. 8). The lunotriquetral interval then is evaluated with the arthroscope in the 6-R portal. Following evaluation of the radial carpal space, the arthroscope is placed in the radial midcarpal space to evaluate for any further signs of lunotriquetral instability. For peripheral tears of the articular disk that extend dorsally, Whipple et al described the outside-in technique that involves placing sutures longitudinally to reattach the central cartilage disk to the ﬂoor of the ﬁfth and sixth extensor compartments [15]. A longitudinal incision is made 12–15 mm in length, incorporating the 6-R portal. The retinaculum of the extensor carpi ulnaris is opened along the radial side and the tendon is retracted radially. Attention is given to trying to preserve the articular branch of the dorsal sensory branch of the ulnar nerve during this incision. A curved cannulated needle is placed through the ﬂoor of the extensor carpi ulnaris through the articular disk. A suture retriever is inserted distally at the radiocarpal level around the inserted needle. A suture then is advanced through the needle and brought out through the dorsal aspect of the capsule with the use of the suture retrievers wire loop. Normally two or three sutures are sufﬁcient to close the tear (Fig. 9). Alternatively, Geissler devised a new arthroscopic technique to simplify the repair of ulnarsided tears of the TFC complex. He used the technology similar to the DePuy Mitek Rapid Lock (DePuy, Inc.; Boston, MA), a hybrid suture device for meniscus repair of the knee. Using

Fig. 8. Arthroscopic view of an acute peripheral tear of the articular disk as seen with the arthroscope in the 3-4 portal in a left wrist.

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Fig. 9. The acute peripheral tear is arthroscopically repaired and secured to the ﬂoor of the sheath of the extensor carpi ulnaris tendon.

this technique, a smaller incision is made over the extensor carpi ulnaris, extending the 6-R portal. The tendon is retracted radially as before. An inserter needle is passed through the articular disk and under direct observation with the arthroscope in the 3-4 portal. The absorbable PLA backstop then is deployed through the inserter needle, across the ulnar-sided tear of the articular disk. The PLA ‘‘top hat’’ then is slid down the attached 2.0 Ethibond (Ethicon; Summerville, NJ) with a pre-tied slipknot securing the top hat against the carpi ulnaris tendon sheath. One or two devices are placed using this technique. This new technique seems promising, particularly for its simplicity. Continued clinical evaluation needs to be performed, however, to evaluate the eﬀectiveness of this technique. Arthroscopic reduction and pinning of acute Grade II and III tears of the lunotriquetral interosseous ligament then is performed (Fig. 10). It is easiest to take the wrist out of the traction tower at this time and place a 0.045 Kirschner wire through a soft tissue protector into the triquetrum. It is vital to insert the Kirschner wire into a soft tissue protector or a 14-gauge needle to protect nerve branches of the dorsal sensory branch of the ulnar nerve. One or two pins may be inserted under ﬂuoroscopy. The wrist then is placed back in traction and the arthroscope is placed in the radial midcarpal portal. It is best to judge rotation from looking across the wrist. The Kirschner wires then may be used as joysticks to reduce the triquetrum to the lunate and control the rotation. Once this has been obtained while viewing directly arthroscopically, the Kirschner wires are advanced into the lunate. Three or four Kirschner wires are used. The position of the wires then is evaluated under ﬂuoroscopy in the AP and lateral planes. Fat droplets are usually seen as the wires pass across the triquetrum into the lunate (Fig. 11). The wrist then is taken out of traction. With the wrist in neutral pronation and supination, the sutures that were passed for repair of the peripheral tear of the articular disk to the TFC complex are tied onto the ﬂoor of the sheath of the extensor carpi ulnaris tendon. The extensor carpi ulnaris tendon sheath then is closed carefully, as is the skin. The Kirschner wire pins are left protruding from the skin (Figs. 12 and 13). The patient then is immobilized in an elbow cast for 4 weeks. The patient is evaluated every 2 weeks to check the pin track sites. At 4 weeks the patient is placed in a short arm cast for an additional 4 weeks of immobilization. At 8 weeks postoperatively, Kirschner wires are removed in the ofﬁce. A removable wrist brace is placed and the patient is started on a grip strength and range of motion program at 3 months postoperatively.

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Fig. 10. Arthroscopic view of an acute Geissler Type II tear of the lunotriquetral interosseous ligament tear. The ligament is no longer concave and has become convex as the tear has extended from the periphery of the articular disk through the lunotriquetral interval.

In patients with a complete Grade IV tear of the lunotriquetral interosseous ligament, an open repair of the interosseous ligament is performed. In patients with an acute peripheral tear of the articular disk and lunotriquetral interosseous ligament and with an ulnar positive wrist, consideration may be given to ulnar shortening at this time. Ulnar shortening in acute ligamentous injuries is controversial, however.

Fig. 11. Fat droplets are seen existing between the carpals as the Kirschner wires are being inserted. This helps conﬁrm correct placement of the Kirschner wires, although the ﬁnal conﬁrmation should be made under ﬂuoroscopy.

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Fig. 12. Anteroposterior radiograph showing correct placement of the Kirschner wires stabilizing an acute tear of the lunotriquetral interosseous ligament in an ulnar neutral wrist.

Management of chronic injuries Management of chronic injuries to the ulnar side of the wrist varies substantially from that of acute injuries, primarily in management of the lunotriquetral interosseous ligament tear. The peripheral tear of the articular disk is repaired arthroscopically, similar to an acute lesion. The literature has not demonstrated a signiﬁcant decrease in healing rate between acute and chronic repairs of peripheral ulnar-sided tears to the articular disk. Management of chronic lunotriquetral instability depends on whether the patient is ulnar positive or ulnar negative. In a patient with a chronic peripheral tear of the articular disk and lunotriquetral instability, the wrist is arthroscopically evaluated. Sutures are placed to repair the peripheral tear of the articular disk, as described earlier (Figs. 14–16). In patients who are ulnar positive with disruption of the lunotriquetral interval, an open shortening of the ulna is performed (Fig. 17) [16–18]. A skin incision approximately 7 cm is made along the ulna border of the distal third of the forearm. Blunt dissection is continued down to protect the dorsal sensory branch of the ulnar nerve. The interval between the ﬂexor carpi ulnaris and extensor carpi ulnaris is opened, exposing the distal third of the ulna. A 7-hole dynamic compression plate then is placed on the volar aspect of the distal ulna. One screw is placed distally in the

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Fig. 13. Lateral radiograph showing correct placement of the Kirschner wires centered between the lunate and triquetrum with no malrotation of the lunate.

plate. An oblique shortening osteotomy is made over the fourth screw hole in the plate. The ulna is shortened and the remaining screws are placed. An oblique lag screw is placed in the fourth screw hole to lag across the ulnar shortening osteotomy (Figs.18 and 19). It is important to monitor the amount of shortening of the ulna under ﬂuoroscopy during the procedure. Management of patients with chronic peripheral tears of the articular disk and lunotriquetral instability in patients who are ulnar negative is controversial. In these patients the wrist is evaluated arthroscopically as described previously, and the peripheral tear of the articular disk is repaired. In patients with Grade II tears of the lunotriquetral interosseous ligament, the torn ﬁbers are debrided mechanically with a shaver in the 6-R portal. Electrothermal shrinkage may play a role in future management of chronic partial tears of the interosseous ligament. Electrothermal shrinkage of tissues has been shown in studies to be beneﬁcial to other joints in the body, particularly the shoulder, but it is important to note that the use of this is controversial and most studies have short follow-up at this time. Electrothermal shrinkage is based on the theory that heating the collagen matrix results in shrinking collagen as the structure denatures. Fibroblasts then grow into the shrunken tissues. Several questions remain unanswered pertaining to the stability of shrunken tissue, such as whether the shrunken tissue acts similarly to normal tissue, and also whether these results will hold up over time.

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Fig. 14. Palpation of the articular disk with the probe in the 6-R portal demonstrating lack of tension in the patient with a chronic ulnar peripheral tear.

The technique is easy. A monopolar or bipolar probe is used. An electrothermal probe is inserted in the 4-5 or 6-R portal with the arthroscope in the 3-4 portal. Following mechanical debridement of the interosseous ligament, an electrothermal probe is used to shrink the remaining portion of interosseous ligament (Fig. 20). This involves primarily the membranous portion, but the probe also contacts the dorsal portion of the interosseous ligament and the

Fig. 15. The periphery of the articular disk then is freshened up with a shaver to facilitate a vascular supply for repair of the chronic peripheral tear. A suture is placed through the articular disk and the wire loop of the suture capture device.

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Fig. 16. Three sutures were placed to stabilize the chronic tear. The capsule has a good blood supply as seen in the periphery.

volar and dorsal portions of the capsule. It is important that the probe moves continuously so as not to concentrate all the heat in any one space. Transverse strips of contracture should be made, leaving normal capsule between the areas that have been contacted with a probe. This is to leave normal capsule to help vascularize and heal the contracted areas. The arthroscope then is placed up in the radial midcarpal portal to evaluate the stability of the lunotriquetral interval following shrinkage. Burns are a possible complication with electrothermal shrinkage, as the

Fig. 17. Arthroscopic view of a chronic Geissler Type III tear between the lunate and triquetrum in this patient with an ulnar positive wrist.

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Fig. 18. Anteroposterior radiograph of the patient with a chronic tear of the periphery of the articular disk and lunotriquetral interval. This is diﬀerent from a patient with ulnar abutment syndrome, who would have a central tear and degenerative changes around the interosseous ligament and possible articular cartilage loss from the ulnar side of the lunate.

wrist is a small joint and irrigation ﬂuid in the wrist may be heated up quickly. When electrothermal shrinkage is used, it should be done with great caution. A separate inﬂow is used and outﬂow through the arthroscopic sheath is continuous. The ﬂow of irrigation is increased during electrothermal shrinkage to help dissipate the heat. The temperature of the irrigation ﬂuid that leaves the arthroscopic cannula is monitored continuously to make sure it is not too hot. The power in the probe may be decreased during shrinkage in the wrist also. Geissler reviewed the results of 19 patients with isolated chronic interosseous ligament tears to the wrist. Seven out of nine patients with shrinkage of a partial chronic tear to the lunotriquetral interosseous ligament had excellent and good results. Grade II tears to the lunotriquetral interosseous ligament did signiﬁcantly better as compared with Grade III tears; shrinkage of Grade III tears is not recommended.

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Fig. 19. Anteroposterior radiograph following arthroscopic repair of the peripheral tear of the articular disk and open ulnar shortening. Shortening of the ulnar helps stabilize the lunotriquetral interval in this patient with a Geissler Type III lunotriquetral interosseous ligament tear through the pull of the ulnar carpal ligaments.

Tolen et al described an arthroscopic technique of ulnolunate-ulnotriquetral ligament plication [19]. In this technique, a number 2.0 polydioxanone sutures (PDS) is placed through a needle that is passed just palmar to the ulnotriquetral and ulnolunate ligaments to encompass the ulnocarpal ligament and enter the radiocarpal joint at the edge of the ulnolunate ligament, approximately 5 mm distal to the articular surface. The sutures are retrieved by using a wire loop retriever brought out through the 6-U portal. Two 0.045-inch smooth Kirschner wires then are placed percutaneously through the lunotriquetral interval. After the reduction of ﬁxation, the triquetrum should be in line with the hamate facet of the lunate. After successful reduction has been achieved, the wrist is removed from traction and the plication sutures are tied beneath the skin at the 6-U portal with a formal neutral rotation. The patient is placed in a Munster cast

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Fig. 20. Arthroscopic view of a monopolar electrothermal probe inserted through the 6-R portal making transverse passes over the Geissler Type II lunotriquetral interosseous ligament tear. The heat from the probe contracts the attenuated interosseous ligament.

for 4 weeks and then gentle rotation is started. At 12 weeks, a sport-speciﬁc or work hardening program is instituted. In their series, Moscol reviewed 20 patients with 13 excellent, 5 good, and 2 fair results [19]. Four minor complications were reported. The author has no particular experience with this technique. A ligament rupture is considered chronic when underestimated, missed, or left untreated, and as a result the two ends have degenerated, diminishing the chance for successful repair. Two major strategies have been proposed for chronic lunotriquetral instability with open reconstruction. One strategy uses a strip of the extensor carpi ulnaris tendon or lunotriquetral fusion. Shin reviewed his results in 57 patients, comparing these two methods for isolated traumatic tears of the lunotriquetral interval with an average follow-up of 9.5 years. In his series, the two methods were comparable and results with residual disability. Tendon reconstruction of the lunotriquetral interval, however, showed a much lower complication rate than arthrodesis. These investigators strongly recommend reconstruction of the lunotriquetral interval with a strip of extensor carpi ulnaris, but attached distally and passed through holes in the lunate and triquetrum, and by tightening the tendon graft around the lunotriquetral interval to provide immediate stability. Fusion of the lunotriquetral interval also has its enthusiasts. Guidera believed most complications of lunotriquetral fusion were the result of a poor indication or technical problems. He used a cancellous bone graft to ﬁll a biconcave space created in the adjoining bones and stabilized the joint with multiple Kirschner wires. He reported 100% consolidation in an average of 50 days in his series of 26 patients. Ligamentous structures to the ulnar side of the wrist are connected intimately. The structures to the TFC complex blend with the ulnocarpal ligaments, which in turn have common insertions with the volar portion of the lunotriquetral interosseous ligament. Rather than a single injury to a particular structure, it is now becoming more apparent that a spectrum of injury to the structures that support the ulnar side of the wrist occurs. As Malone has documented, a peripheral tear of the articular disk rarely is an isolated event, but is the principle constitute of a multicomponent injury to the ulnar side of the wrist [5]. The soft tissue damage not only includes the peripheral tear of the articular disk, but that of the extensor carpi ulnaris tendon sheath, and in more severe

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cases, the ulnar, carpal, and lunotriquetral interosseous ligaments. Awareness of this traumatic spectrum pathology is important in the management of these injuries. Wrist arthroscopy can be a valuable adjunct in the management of the spectrum of injury that occurs to the ulnar side of the wrist. This is particularly true when radiographs are normal. It is particularly diﬃcult to evaluate for lunotriquetral instability on plain radiographs and other imaging and other modalities. In patients with persistent ulnar-sided wrist pain despite immobilization, arthroscopic evaluation should be considered. It is important that the physician be aware of the spectrum of injury that may occur to the ulnar side of the wrist, particularly with extension to the lunotriquetral interosseous ligaments. Management of acute injuries has a signiﬁcantly better prognosis than chronic injuries to the wrist. Weiss reviewed his results in arthroscopic debridement of partial and complete tears of the lunotriquetral interosseous ligaments at an average of 27 months following the procedure [20]. Twenty-six of the 33 patients who had complete tear of the lunotriquetral interosseous ligament and all 43 patients who had a partial tear had complete resolution or a decrease in their symptoms. Patients tolerated debridement of the lunotriquetral interosseous ligament better than the scapholunate interosseous ligament in his series, possibly because of the lower stresses applied to the ulnar side of the wrist. Osterman reported on a group of 20 patients with an average age of 36 years who presented with ulnar-sided wrist pain [21]. Nine of the 20 patients were ulnar positive and no patient had a VISI collapse. All patients were conﬁrmed to have a tear of the lunotriquetral interosseous ligament. Associated arthroscopic ﬁndings in his series were synovitis in 17 patients, lunotriquetral chondromalacia in 8 patients, central tears of the TFC complex in 8 patients, ulnar extrinsic ligament tears in 6 patients, and triquetral hamate chondromalacia in 6 patients. Lunotriquetral interosseous ligament was debrided in all patients. In his series the lunotriquetral interval was pinned percutaneously with two to three Kirschner wires. In average 2-year follow-up, 80% of the patients had good to excellent relief of pain and preoperative symptoms. This series demonstrates the associated pathology that may occur with lunotriquetral interosseous ligament injuries and the difﬁculty in evaluating the ﬁnal results with associated pathology. Westkaemper et al reported that four of ﬁve patients with complete lunotriquetral ligament tears had a poor result with arthroscopic debridement alone, irrespective of associated injuries [22]. He suggested that results may be improved by pinning the lunotriquetral interval, similar to Osterman’s study. The studies of Weiss and Westkaemper show that arthroscopic debridement alone for complete chronic tears of the lunotriquetral interosseous ligament had a lower success rate than for partial ligament injuries. If during arthroscopic evaluation a complete tear of the lunotriquetral interosseous ligament is identiﬁed, particularly in chronic injuries, further treatment is potentially necessary. Trauma to the ulnar side of the wrist usually involves a spectrum of injury. A peripheral tear to the articular disk may be the ﬁrst stage of a complex, multifactorial ligamentous injury. The physician needs to be aware of the wide spectrum of injury that can occur with these injuries and should manage accordingly. Arthroscopic evaluation is a useful adjunct in the management of these injuries when imaging studies are normal and clinical evaluation is consistent with a soft tissue injury to the TFC complex or lunotriquetral interosseous ligament.

References [1] Weiss APC, Akelman E, Lambiase R. Comparison of the ﬁndings of triple injection cinearthrography of the wrist with those of arthroscopy. J Bone Joint Surg 1996;78A:348–56. [2] Potter HG, Asnis-Ernberg L, Weiland AJ, Hotchkiss RN, et al. The utility of high-resolution magnetic resonance imaging in the evaluation of the triangular ﬁbrocartilage complex of the wrist. J Bone Joint Surg 1997;79A:1675–84. [3] Adolfsson L. Arthroscopic diagnosis of ligament lesions of the wrist. J Hand Surg 1994;19B:505–12. [4] Palmar AK. Triangular ﬁbrocartilage disorders, injury patterns, and treatments. Arthroscopy 1990;6:125–32. [5] Melone CP, Nathan R. Traumatic disruption of the triangular ﬁbrocartilage complex. Clin Orthop 1992;275:65–73. [6] Palmar AK. Triangular ﬁbrocartilage complex lesions: a classiﬁcation. J Hand Surg 1989;14:594–606. [7] Chung KC, Zimmerman NB, Travis MT. Wrist arthrography versus arthroscopy: a comparative study of 150 cases. J Hand Surg 1996;21A:591–4. [8] Ritter M, Chang DS, Ruch DR. The role of arthroscopy in the treatment of lunotriquetral ligament injuries. Hand Clin 1999;15:445–54.

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[9] Geissler WB, Freeland AE, Savoie FH, McIntyre LW, Whipple TL. Intracarpal soft tissue lesions associated with an intra-articular fracture of the distal end of the radius. J Bone Joint Surg 1996;78A:357–65. [10] Geissler WB, Fernandez DL, Lamey DM. Distal radioulnar joint injuries associated with fractures of the distal radius. Clin Orthop 1996;327:135–46. [11] Trumble TE, Gilbert M, Vedder N. Isolated tears of the triangular ﬁbrocartilage: management by early arthroscopic repair. J Hand Surg 1997;22A:57–65. [12] Osterman AL. Arthroscopic debridement of triangular ﬁbrocartilage complex tears. Arthroscopy 1990;6:120–4. [13] Herrmannsdorfer JD, Kleinman WB. Management of chronic peripheral tears of the triangular ﬁbrocartilage complex. J Hand Surg 1991;16:340–6. [14] Whipple TL, Marotta JJ, Powell JH. Techniques of wrist arthroscopy. Arthroscopy 1986;2:244–53. [15] Corso SJ, Savoie FH, Geissler WB, Whipple TL, Jiminez W, Jenkins N. Arthroscopic repair of peripheral avulsion of the triangular ﬁbrocartilage complex of the wrist: a multicenter study. Arthroscopy 1997;13:78–84. [16] Boulas HJ, Milek MA. Ulnar shortening for tears of the triangular ﬁbrocartilaginous complex. J Hand Surg 1990; 15:415–20. [17] Hulsizer D, Weiss AP, Akelman E. Ulna shortening osteotomy after failed arthroscopic debridement of the triangular ﬁbrocartilage complex. J Hand Surg 1997;22A:694–8. [18] Trumble TE, Gilbert M, Vedder N. Ulnar shortening combined with arthroscopic repairs in the delayed management of triangular ﬁbrocartilage tears. J Hand Surg 1997;22:807–13. [19] Tolan S, Savoie FH, Field LD. Arthroscopic management of lunotriquetral instability. Atlas Hand Clin 2001;6: 275–83. [20] Weiss AP, Sachar K, Glowacki KA. Arthroscopic debridement alone for intercarpal ligament tears. J Hand Surg 1997;22A:344–9. [21] Osterman AL, Seidman GD. The role of arthroscopy in the treatment of lunotriquetral ligament injuries. Hand Clin 1995;11:41–50. [22] Westkaemper JG, Mitsionis G, Gianna Kopoulos PN, et al. Wrist arthroscopy for the treatment of triangular ﬁbrocartilage complex injuries. Arthroscopy 1998;14:479–83.

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Lasers and electrothermal devices in the treatment of lunotriquetral instability Daniel J. Nagle, MD Clinical Orthopaedics, Northwestern University, 448 East Ontario Street, Suite 500, Chicago, IL 60611, USA

Lunotriquetral instability describes a spectrum of pathology ranging from simple attenuation to complete disruption of the lunotriquetral (LT) interosseous ligament and the adjacent dorsal radiocarpal and intercarpal ligaments (DRC and DIC) [1]. Stabilization of the unstable lunotriquetral joint has proven to be a challenge. The prospect of a minimally invasive stabilization technique (thermal shrinkage) is attractive, particularly when contrasted with other more invasive stabilization techniques, such as LT fusion, ulnar column fusion (lunate, triquetrum, capitate, hamate), reconstruction with tendon graft, and ulnar shortening osteotomy.

Anatomy and pathology The major stabilizing structure of the LT joint is the LT interosseous ligament. This ligament is composed of ﬁbrocartilage centrally with an increasing amount of collagen dorsally and palmarly. The ligament is stout dorsally and palmarly and thinner centrally. Although the dorsal and palmar potions of the ligament lend themselves to thermal shrinkage because of the high concentration of type I collagen [2], the central ﬁbrocartilaginous portion of the ligament is poor in type I collagen and is not as ‘‘shrinkable.’’ The ulnotriquetral and ulnolunate ligaments (ulnocarpal ligaments) also contribute to the stability of the LT joint. The ‘‘V’’ disposition of these two ligaments permits them to be used to stabilize the LT joint (Fig. 1) [3]. Proximal traction on these ligaments creates vectors of force directed toward the LT joint line, stabilizing the LT joint. The ulnocarpal ligaments are high in collagen and are shrinkable (see Fig. 1). Shrinkage of the dorsal carpal ligaments might be considered in the treatment of LT instability. Viegas has shown that the DRC is a signiﬁcant stabilizer of the ulnar aspect of the wrist and that its disruption can lead to a VISI deformity [4]. He has shown that the DRC ligament originates on the distal dorsal radius ulnar to Lister’s tubercle and inserts on the dorsal ulnar aspect of the lunate, the dorsal lunotriquetral interosseous ligament (LTI), and the dorsal ridge of the triquetrum (Fig. 2A). This anatomy would suggest that shortening of the DRC ligament would probably not stabilize the LT joint, because the lunate attachment would ‘‘short circuit’’ the transmission of force to the triquetrum (Fig. 2B). The DIC originates on the dorsal aspect of the triquetrum and inserts on the LTI, the dorsal aspect of the lunate and scapholunate interosseous ligament (SLI), the dorsal ridge of the scaphoid, and in some cases on the trapezoid and trapezium (Fig. 3). Shortening the DIC ligament as it passes between the triquetrum and lunate theoretically could create vectors of force that produce not only dorsal LT joint compression, but also palmar LT joint divergence (Fig. 4). The anatomy of the DRC and DIC ligaments suggests that their shrinkage may not be helpful in the treatment of LT instability. Further anatomic and biomechanic studies are needed E-mail address: [email protected] 1082-3131/04/$ - see front matter Ó 2004 Elsevier Inc. All rights reserved. doi:10.1016/j.ahc.2003.12.003

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Fig. 1. Lunotriquetral and ulnocarpal ligaments. Note the ‘‘V’’ conﬁguration of the ulnocarpal ligaments.

to clarify this issue before their shrinkage can be recommended in the treatment of LT instability.

Lasers The bulk of the research done on laser/radio frequency (RF) assisted arthroscopy has been done in the knee and shoulder. There has been some controversy in regard to the use of lasers in the knee because of the report of four cases of femoral condyle avascular necrosis [5]. Whether or not the laser played a role in these cases remains to be seen. Avascular necrosis also has been reported after meniscectomy performed using mechanical devices [6]. Janecki et al reviewed 504 laser assisted knee arthroscopies and noted no new cases of avascular necrosis of the femur [7]. There was also concern regarding the sonic shock produced by the vaporization of the water at the tip of the Holmium:YAG (Ho:YAG) laser. Gerber et al [8] have studied this issue and have concluded that there is no acoustic trauma associated with the use of the Ho:YAG laser. The Ho:YAG laser is currently the laser du jour for wrist arthroscopy. Other lasers have been used in arthroscopy (CO2, Neodynium:YAG, Erbium and excimer) but have been abandoned in favor of the Ho:YAG laser. The Ho:YAG laser functions (as does the CO2 laser) in the infrared region of the electromagnetic spectrum at 2.1 nm. In contrast to the CO2 laser, the Ho:YAG energy is able to be transmitted through a quartz ﬁber and functions well under water. Also, it is well absorbed by cartilage, ﬁbrocartilage, synovial tissue, scar, and hemoglobin. This last point explains the Ho:YAG’s hemostatic capabilities. The Ho:YAG laser functions by superheating the tissues to be ablated. When the laser ﬁres, it creates a small bubble of water vapor at its tip (the ‘‘Moses eﬀect’’). The tissue within this bubble absorbs most of the laser energy and is vaporized, leaving a layer of ‘‘caramelized’’ protein behind but no char. Beyond the vapor bubble the laser energy is quickly attenuated as it is absorbed by the water in the joint. This drop-oﬀ in energy allows the surgeon to titrate the

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Fig. 2. (A) Dorsal radiocarpal ligament. Points of attachment: A, radius; B, dorsal lunate; C, dorsal lunotriquetral ligament; D, dorsal triquetrum. (B) Interruption of force transmission to the LT joint at the insertion of the DRC ligament on the dorsal lunate.

amount of energy transmitted to the tissues in the joint. By defocusing the laser (pulling the tip away from the tissue), the tissue is taken out of the Moses bubble and less energy is imparted to the tissue. This allows the melting of chondromalacic fronds and capsular shrinkage without injuring adjacent tissues. The water in the joint not only absorbs the laser energy, but it also acts as a large, continually renewed heat sink. The problem of heat build-up and collateral tissue damage is also addressed by pulsing the laser light. The time between pulses allows the tissues outside the ablation zone to transmit the energy they absorb to the heat sink (water) and thus remain protected from thermal injury. Continuously applied laser energy does not permit the ﬂow of heat energy away from the ablation site and results in signiﬁcant collateral damage. With appropriate technique, one thus can modulate the energy imparted to the tissues by changing the laser pulse frequency, by changing the amount of energy per pulse, and ﬁnally by focusing or defocusing the laser.

Fig. 3. Dorsal intercarpal ligament (DIC). DIC attachments: A, B, scaphoid; C, scapholunate interosseous ligament; D, lunate; E, lunotriquetral interosseous ligament; F, triquetrum.

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Fig. 4. End on view of the proximal carpal row. DIC shrinkage (large arrows) in the region of the LTI theoretically could lead to dorsal lunotriquetral convergence and palmar lunotriquetral divergence (small arrows).

Radio frequency RF devices, like lasers, ablate/shrink tissue thermally. The RF devices transmit energy to the tissues by way of radio frequency waves in the 100–450 KHz range. This electromagnetic energy causes the electrolytes within the tissue to oscillate rapidly. This molecular oscillation creates friction within the tissue that in tern heats the tissue. The RF energy produces enough friction to either denature the collagen and cause shrinkage or vaporize the tissue. RF devices exist in two ﬂavors, monopolar and bipolar. Monopolar units require that a grounding pad be attached to the patient, whereas the bipolar devices do not. The RF devices oscillate the polarity of the active and passive electrodes to produce the RF energy. The energy of the monopolar devices ﬂows from the active electrode through the tissue being treated to the passive ground electrode. Bipolar devices have the active and passive electrodes in the tip of the probe. The energy ﬂows from the active electrode back to the passive electrode, passing through the superﬁcial layers of the tissue near the probe tip (Fig. 5). It follows that the depth of penetration of the monopolar devices is greater than that noted with bipolar devices (4 mm versus 0.2–0.3 mm). In the case of the monopolar devices, the depth of tissue penetration also depends on the impedance of the tissue. The RF current follows the path of least resistance. The penetration of the RF energy increases as the impedance decreases. It follows that RF energy penetrates deeper into a ligament than into cartilage (Table 1). Monopolar and bipolar devices require a conductive milieu, such as normal saline or lactated ringer’s solution. The tips

Fig. 5. Monopolar: electrical current is conducted into the tissue to the grounding pad. Bipolar: current is conducted away from the tip to the return electrode on the probe shaft.

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D.J. Nagle / Atlas Hand Clin 9 (2004) 59–66 Table 1 Tissue impedance Tissue/substance

Impedance X

Saline Ligaments Cartilage Bone

90–120 100–140 350–500 1100

of the RF probes exist in many shapes and sizes to accommodate the anatomy of the problem being treated. Although what follows focuses on the use of the Ho:YAG laser, it should be kept in mind that RF devices and lasers are, for the most part, interchangeable [9]. The RF probes can be used through the same portals described for the laser probes, and like the Ho:YAG laser, can be used to ablate and shrink tissue. One must be careful, however, to not overheat the joint or the structures adjacent to the joint while using RF wands. The RF energy penetrates the tissue to a depth of 4 or more millimeters, as compared with the 0.5-mm penetration of the laser. Adequate inﬂow/outﬂow is essential while using the RF devices. Prolonged use of the RF probes without an adequate heat sink (ﬂuid ﬂow) can lead to diffuse thermal injury of the joint surfaces and adjacent periarticular structures. Capsular shrinkage Wrist capsular shrinkage may oﬀer an attractive alternative to more invasive treatments for subtle forms of carpal instability. It seems logical to apply what has been learned from shoulder capsular shrinkage to the wrist. The basic science of capsular shrinkage should be the same for both joints. The wrist is not the shoulder, however, and extrapolation of shoulder data to the wrist may not be possible. The biology of capsular shrinkage has been studied extensively in animal models. Capsular shrinkage is a reﬁned ‘‘hot poker’’ technique. The triple helix of collagen unwinds when heated to 60 C, maximum shrinkage being achieved from 65 –75 C (Fig. 6). The hydrogen bonds holding the type I collagen triple helix together rupture as the collagen is heated beyond 60 C. As the collagen triple helix unwinds, it shortens (Fig. 7). This shortening can reach 50% of the resting length of the untreated collagen. The shortened denatured collagen acts as scaffolding onto which new collagen is deposited [10]. The new collagen ﬁbers maintain this shortened conformation, thus assuring the long-term maintenance of the shortening. Biomechanic studies have demonstrated that the tensile strength of heated collagen decreases rapidly and does not return to normal values for 12 weeks [11]. The tensile strength returns to nearly 80% of normal by 6 weeks after heating (Fig. 8). This transient loss of tensile strength would suggest that the application of stress to recently heated collagen is contraindicated. Premature loading of the shrunken collagen leads to a lengthening of the collagen. This has been veriﬁed in an animal model [12,13]. Based on these data, it seems reasonable to recommend at

Fig. 6. Collagen shrinkage as a function of temperature.

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Fig. 7. (A) Triple helix of native type I collagen. (B) Thermally induced shrinkage of type I collagen.

least 6–8 weeks of joint immobilization after capsular shrinkage. Clearly, heavy loading of the joint should be avoided for 12 weeks.

Indications for capsular shrinkage As stated previously, LT instability is the manifestation of a spectrum of pathology. The following are three possible LT instability scenarios. 1. Isolated LT interosseous ligament attenuation without gross LT instability 2. Isolated LT interosseous ligament disruption without gross instability 3. LT interosseous ligament disruption associated with DIC or DRC or ulnocarpal ligament disruption with gross instability Scenarios 1 and 2 lend themselves to capsular shrinkage, because the integrity of the LT stabilizers, although compromised, is maintained. Shrinkage in scenario 3 will be ineﬀective because of the extensive disruption of the LT stabilizers.

Technique Shrinkage requires low energy settings. The RF devices must be adjusted to heat the tissue to a temperature of 65 –75 C. It is wise to start at low energy and slowly increase the energy output until the desired shrinkage is observed. The laser should be set to very low energy, ie, 0.2–0.5 Joules at 15 pulses per second (3.0–7.5 W). The laser is held away from the target ligament and slowly advanced until the ligament is seen to shrink. Once the shrinkage has stopped, further lasing only further weakens the ligament without increasing the shrinkage. The color of the ligament changes from white to light yellow during the shrinkage. Lu et al have

Fig. 8. Tensile strength of heat-treated collagen as a function of time.

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suggested that a crosshatching shrinkage pattern optimizes the ingrowth of healthy tissue and hastens the recovery of the ligament [14]. During the shrinkage, the traction on the wrist should be reduced as much as possible. The ﬁrst step in assessing and treating an LT instability is a complete diagnostic wrist arthroscopy, including evaluation of the midcarpal joint and dynamic testing of the LT joint under direct arthroscopic visualization (arthroscopic shuck test.) The standard wrist arthroscopy setup and portals are used. Clear visualization of the LT joint almost always requires debridement of the ulnocarpal joint. Once the true extent of the pathology is determined, the decision whether or not to proceed with capsular shrinkage can be made. Shrinkage of the dorsal and palmar aspects of an attenuated but intact LT ligament (scenario 1) is performed with the scope in the 3-4 portal and the laser/RF device in the 4-5 or 6R portal. Low energy settings are used (see previous mention.) The traction is reduced to the minimum required to safely complete the surgery. The ulnocarpal ligaments are also shrunk, taking advantage of their ‘‘V’’ disposition (see Fig. 1). The treatment of LT instability as described in scenario 2 can still include capsular shrinkage of any residual intact dorsal or palmar LT interosseous ligament. The ulnocarpal ligaments also should be shrunk. Occasionally only a partial tear of the LT ligament without LT instability is found at arthroscopic examination. The simple ablation of the free edge of the torn LT interosseous ligament is often all that is needed in such cases [15,16]. Pinning of the LT joint is probably not needed in all cases. If there is little gapping and a mild degree of instability, LT pinning adds little to the ﬁnal outcome. On the other hand, if more signiﬁcant gapping and instability are noted, the placement of an LT pin (taking care to avoid the dorsal sensory branch of the ulnar nerve) would seem prudent. The pin should be left in place for at least 8 weeks. Postoperative care The physiology of the collagen repair after thermal treatment demands prolonged immobilization (see previous mention). Postoperative immobilization therefore should include 8 weeks of strict immobilization followed by an additional 4 weeks of splinting combined with light active range of motion. Only at 12 weeks should strengthening exercises be started. William Geissler, MD reported the early results of monopolar RF shrinkage for LT instability in nine patients, four with Grade II and ﬁve with Grade III tears of the LT interosseous ligament [17,18]. He followed his patients for an average of 8 months and concluded that capsular shrinkage for LT instability is effective. He also noted, however, that those patients with Grade II instability do better than those with Grade III instability (Table 2). The author’s experience with these techniques echoes that of Dr. Geissler. The author has used these techniques in a limited number of patients with mild (Geissler II) LT instability with good success, but the number of cases is too small and the follow-up too short to permit an accurate analysis of its ultimate eﬃcacy. Summary The rationale for treating lunotriquetral instability with thermal modiﬁcation of the LT joint stabilizing structures includes the fact it is minimally invasive, uses techniques that are Table 2 Results of LT interosseous ligament shrinkage [17] Result Excellent Good Fair Poor

Grade II LT instability

Grade III LT instability

3 1

1 2 1 1

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associated with low complication rates [19], and preserves wrist anatomy. Based on the physiology of the healing of thermally treated type I collagen, prolonged immobilization of the treated wrist is of paramount importance. Clinical and laboratory studies, however, are needed to further clarify the roll of this technique in the treatment of lunotriquetral instability.

References [1] Viegas SF, Yamaguchi S, Boyd NL, Patterson RM. The dorsal ligaments of the wrist: anatomy, mechanical properties, and function. J Hand Surg [Am] 1999;24A(3):456–68. [2] Berger RA. Ligament anatomy. In: Cooney WP, Linscheid RL, Dobyns JH, editors. The wrist, diagnosis and operative treatment. St. Louis: Mosby; 1998. p. 91–3. [3] Moskal MJ, Savoie FH III, Field LD. Arthroscopic capsulodesis of the lunotriquetral joint. Clin Sports Med 2001; 20(1):141–53. [4] Viegas SF, Patterson RM, Peterson PD, et al. Ulnar-sided perilunate instability: an anatomic and biomechanic study. J Hand Surg 1990;15A:268–78. [5] Garino JP, Lotke PA, Sapega AA, Reilly PJ, Esterhai JL Jr. Osteonecrosis of the knee following laser-assisted arthroscopic surgery: a report of six cases. Arthroscopy 1995;11:467–74. [6] Johnson TC, Evans JA, Gilley JA, DeLee JC. Osteonecrosis of the knee after arthroscopic surgery for meniscal tears and chondral lesions. Arthroscopy 2000;16(3):254–61. [7] Janecki CJ, Perry MW, Bonati AO, Bendel M. Safe parameters for laser chondroplasty of the knee. Lasers Surg Med 1998;23:141–50. [8] Gerber BE, Asshauer T, Delacretaz G, Jansen T, Oberthur T. Biophysical bases of the effects of holmium laser on articular cartilage and their impact on clinical application technics. Orthopaed 1996;25:21–9. [9] Osmond C, Hecht P, Hayashi K, Hansen S, Fanton GS, Thabit G III, Markel MD. Comparative effects of laser and radiofrequency energy on joint capsule. Clin Orthop 2000;(375):286–94. [10] Lopez MJ, Hayashi K, Vanderby R Jr, Thabit G III, Fanton GS, Markel MD. Effects of monopolar radiofrequency energy on ovine joint capsular mechanical properties. Clin Orthop 2000;(374):286–97. [11] Hecht P, Hayashi K, Lu Y, Fanton GS, Thabit G III, Vanderby R Jr., Markel MD. Monopolar radiofrequency energy effects on joint capsular tissue: potential treatment for joint instability. An in vivo mechanical, morphological, and biochemical study using an ovine model. Am J Sports Med 1999;27(6):761–71. [12] Naseef GS III, Foster TE, Trauner K, Solhpour S, Anderson RR, Zarins B. The thermal properties of bovine joint capsule. The basic science of laser- and radiofrequency-induced capsular shrinkage. Am J Sports Med 1997;25(5): 670–4. [13] Hayashi K, Markel MD. Thermal capsulorrhaphy treatment of shoulder instability: basic science. Clin Orthop 2001;(390):59–72. [14] Lu Y, Hayashi K, Edwards RB III, Fanton GS, Thabit G III, Markel MD. The effect of monopolar radiofrequency treatment pattern on joint capsular healing. In vitro and in vivo studies using an ovine model. Am J Sports Med 2000;28(5):711–9. [15] Ruch DS, Poehling GG. Arthroscopic management of partial scapholunate and lunotriquetral injuries of the wrist. J Hand Surg [Am] 1996;21(3):412–7. [16] Weiss AP, Sachar K, Glowacki KA. Arthroscopic debridement alone for intercarpal ligament tears. J Hand Surg [Am] 1997;22(2):344–9. [17] Geissler W. Electrothermal shrinkage in interosseous ligament tears. Presented at the American Association for Hand Surgery Annual Meeting. Koloa, Kauai, Hawaii, January 10, 2003. [18] Geissler WB. Arthroscopically assisted reduction of intra-articular fractures of the distal radius. Hand Clin 1995;11: 19–29. [19] Blackwell RE, Jemison DM, Foy BD. The holmium:Yttrium-aluminum-garnet laser in wrist arthroscopy: a ﬁveyear experience in the treatment of central triangular ﬁbrocartilage complex tears by partial excision. J Hand Surg 2001;26A:77–84.

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Open treatment options for lunotriquetral instability and dissociation Steven L. Moran, MD*, Alexander Y. Shin, MD Department of Orthopaedic Surgery, Division of Hand and Microvascular Surgery, Mayo Clinic, 200 1st Street Southwest, Rochester, MN 55901, USA

Isolated injury of the lunotriquetral (LT) interosseous membrane and associated structures is uncommon and less understood than scapholunate (SL) dissociation. A spectrum of injury may be seen from isolated membrane tears to frank dislocation and from dynamic to static carpal instability ﬁndings. The diagnosis is usually confounded by the many possible causes of ulnarsided wrist pain and frequently normal radiographs. Even the mechanism of injury is variable, including ulnar positive variance, perilunate or reverse perilunate injury, or dorsally applied forces. Appropriate treatment requires assessment of the degree of instability and chronicity of the injury. Treatment options have included steroid injection, immobilization, ligament repair, ligament reconstruction with tendon grafts, limited intercarpal arthrodesis, and ulnar shortening.

Mechanism of injury Perilunate injury The mechanism of isolated LT ligament injury remains controversial. It is likely that more than one mechanism plays a role. For example, perilunar dislocations occur when a force is applied to the thenar area with the wrist positioned in dorsiﬂexion and ulnar deviation [1–4]. The resultant intercarpal supination results in a progressive injury pattern in a radial to ulnar direction, following a bony or purely ligamentous path about the lunate. Injury to the LT support structures occurs in stage III, after SL injury or scaphoid fracture. These injuries usually result in a dorsal intercollated segment instability (DISI) deformity unless the SL portion heals spontaneously or with intervention [5,6]. In this instance, ulnar-sided pathology predominates. Reverse perilunate injury The presence of an isolated LT tear may represent a reverse pattern of the perilunate injury pattern originating on the ulnar side of the wrist [6–8]. Although no laboratory studies have conﬁrmed this mechanism, it seems likely that such an injury could occur by a fall on the outstretched hand positioned in extension and radial deviation. The resultant intercarpal pronation would overload the ulnar–volar ligament structures and result in LT ligament injury without SL disruption.

* Corresponding author. E-mail address: [email protected] (S.L. Moran). 1082-3131/04/$ - see front matter Ó 2004 Elsevier Inc. All rights reserved. doi:10.1016/S1082-3131(03)00078-5

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Dorsally applied force Weber has postulated that isolated LT tears may occur with the wrist palmar ﬂexed [9]. A dorsally applied force then permits the LT interosseous ﬁbers to fail, sparing the palmar radiolunotriquetral ligaments. The integrity of this ligament tethers the palmar pole of the lunate, creating an axis for palmar ﬂexion. Other etiologies Patients without a history of trauma may have degenerative lunotriquetral lesions or inﬂammatory arthritis that lead to LT instability [10,11]. An ulna plus variant may facilitate LT membrane degeneration by a wear mechanism or by altering intercarpal kinematics [12–14].

Pathomechanics A complete LT tear alone is not suﬃcient to cause the carpus to assume a volar intercollated segment instability (VISI) stance. Sectioning of volar and dorsal LT ligaments results in a slight divergence of the triquetrum and lunate at extremes of wrist ﬂexion and radial deviation but no VISI collapse unless considerable compressive forces are applied [8]. Additional tear or attenuation of secondary restraints is necessary to create static carpal instability. Palmar and dorsal carpal ligaments may play a role as secondary restraints. Two recent anatomic studies have implicated palmar ligament injury in the development of VISI in LT dissociation. Trumble et al [15] created carpal collapse with division of the ulnar arcuate ligament, whereas Viegas et al and Ritt [16–18] found the palmar LT ligament most important. Disruption of the LT ligament leads to an increase in the moment arm of the ﬂexor carpi ulnaris (FCU) tendon; this may contribute to additional clinical sequelae seen in patients [19]. Dorsal radiocarpal and intercarpal ligament sectioning also produces static VISI following LT ligament injury [16,17,20]. Loss of dorsal ligament integrity allows the lunate to ﬂex more easily in part by shifting the point of capitate contact palmar to the lunate axis of rotation (Fig. 1). Although LT ligament dissociation can result in a VISI deformity, it is important to remember that not all VISI deformities are the result of LT ligament injury. Carpal instability of the nondissociative type (CIND) of the radiocarpal, midcarpal, or combined radiocarpalmidcarpal joints also can lead to VISI deformity [21].

Fig. 1. The normal dorsal ligament integrity prevents volar ﬂexing of the lunate (bottom). Loss of the dorsal ligament integrity allows the lunate to ﬂex more easily in part by shifting the point of capitate contact palmar to the lunate axis of rotation (top).

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In describing injuries of the LT ligament, it is imperative to distinguish between dynamic and static instability. LT ligament injuries with normal conventional radiographs and dynamic instability (present only under load or in certain positions) are classiﬁed as LT attenuations or tears. Fixed carpal collapse (VISI) on conventional radiographs represents static instability and is classiﬁed as LT ligament dissociation.

Evaluation of lunotriquetral injuries Lunotriquetral ligament injury occurs as a spectrum ranging from partial tears with variable pain and weakness to complete dissociation with a static collapse causing a fork-like deformity of the wrist and prominence of the distal ulna [6,22]. Some patients with radiographic evidence of persistent LT malalignment after perilunate dislocation may have minimal symptoms and a satisfactory outcome [23]. Symptomatic sprains present invariably with ulnar wrist pain [8]. Symptoms are usually intermittent and are especially prominent with deviation or rotation of the wrist [22]. They include diminished motion, weakness, a sensation of instability or giving way, and ulnar nerve paresthesias. A painful wrist clunk with deviation is usually present [8]. A history of a speciﬁc injury is usually present [8]. The mechanism of injury should be determined if possible. A fall on the dorsiﬂexed wrist with a hypothenar contact point should increase the suspicion of ulnar-sided instability [24]. A careful examination of the wrist is needed in the evaluation of ulnar-sided wrist pain to diﬀerentiate LT injury from other lesions. A variety of lesions may cause medial wrist symptoms and include distal radioulnar joint subluxation or arthrosis, ulnar head chondromalacia, triangular ﬁbrocartilage injury, triquetrohamate instability, hamate fractures, ulnar styloid impingement syndrome, pisotriquetral injury, extensor carpi ulnaris subluxation, periarticular calciﬁcation, and ulnar neurovascular syndromes [25,26]. Examination should encompass the entire ulnar side of the wrist. Ulnar deviation with pronation and axial compression elicits dynamic instability with a painful snap if a nondissociative midcarpal or LT injury is present. Palpation always demonstrates point tenderness at the LT joint [6,8]. A palpable wrist click is occasionally signiﬁcant, particularly if painful and occurring with radioulnar deviation. Provocative tests that demonstrate LT laxity, crepitus, and pain are helpful to accurately localize the site of pathology. Three tests have been described that are useful, including the LT ballottement, compression, and shear tests [8,24,27]. Compression of the triquetrum in the ulnar snuﬀ box applies a radially directed compressive force against the triquetrum. Pain elicited with this maneuver may be of lunotriquetral origin, but may also arise from the triquetrohamate joint [24].Ballottement of the triquetrum, described by Reagan and Linscheid [8], is performed by grasping the pisotriquetral unit between the thumb and index ﬁnger of one hand and the lunate between the thumb and index ﬁnger of the other. If positive, increased anteroposterior laxity is noted, together with pain. The shear test described by Kleinman [27] is performed with the forearm in neutral rotation and the elbow on the examination table. The examiner’s contralateral thumb is placed over the dorsum of the lunate. With the lunate supported, the examiner’s ipsilateral thumb loads the pisotriquetral joint from the palmar aspect, creating a shear force at the LT joint. These tests are considered positive when pain, crepitus, and abnormal mobility of the LT joint are demonstrable. Comparison of ﬁnding with the contralateral wrist is important. Other ﬁndings on physical examination commonly include limited range of motion and diminished grip strength [6]. A nondissociative instability pattern secondary to midcarpal laxity at the triquetrohamate joint should be ruled out, because symptoms may be similar. The possibility of injury at both levels should be considered [5,26,28].

Diagnostic studies Imaging studies useful in the evaluation of LT injuries include routine wrist radiographs, motion studies, tomography, arthrography, videoﬂuoroscopy, scintigraphy, and MRI.

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Fig. 2. A 27-year-old male status post a fall on the outstretched dorsiﬂexed and ulnar deviated wrist with resultant perilunate injury. The scapholunate ligament healed with slight diastasis and the lunotriquetral dissociation persisted. (A) AP radiographs demonstrate the break in Gilula’s arc I and II with overlap of the lunate and triquetrum. (B) Lateral radiographs demonstrate the VISI collapse of the carpus, implying injury to other supporting ligaments of the lunate and triquetrum.

Radiographs of LT tears are often normal. LT dissociation results in a disruption of Gilula’s arc I and II, with proximal translation of the triquetrum or LT overlap (Fig. 2) [8,29]. Unlike SL injuries, no LT gap occurs. A static VISI deformity implies injury not only to the LT ligament, but also additional dorsal or palmar ligament attenuation [8,15,18,20]. Motion studies, including deviation and clenched ﬁst anteroposterior views, are often helpful. In LT dissociation, the normal reciprocal motion of scaphoid, lunate, and distal row is accentuated in deviation with diminished triquetral motion [24]. This increased palmar ﬂexion of the scaphoid and lunate in radial deviation without change of the triquetrum is a manifestation of the loss of proximal row integrity present in normal wrists [8]. A careful evaluation of the lunate and triquetrum on lateral radiographs may reveal a relative malalignment between them in the absence of frank carpal collapse [6]. The perimeters of the triquetrum and lunate may be traced out and their relationship assessed [6,8]. The longitudinal axis of the triquetrum, deﬁned as a line passing through the distal triquetral angle and bisecting the proximal articular surface, forms an angle with the lunate of 14° (range, +31° to ÿ3°). LT dissociation results in a negative angle (mean value, ÿ16°) [8]. If a VISI deformity is present with LT dissociation, the SL and capitolunate angles are altered. The SL angle is diminished from its normal 47°–40°or less [30,31]. The lunate and capitate, which are normally colinear, collapse in a zigzag fashion, resulting in an angle greater than 10°. The lunate center of rotation lies dorsal to the mid axial line of the capitate and may exhibit slight dorsal subluxation. Arthrography is valuable, demonstrating leakage of dye at the LT interspace; however, agerelated lunotriquetral membrane perforations are common [10,32]. Some communication of radiocarpal and midcarpal joints occur in as many as 13% of normal subjects [33,34]. Viegas demonstrated that 36% of cadaver wrist dissections had lunotriquetral tears [35], and Cantor Table 1 Arthroscopic classiﬁcation of the tears of the intracarpal ligaments Grade

Description

I

Attenuation or hemorrhage of the interosseous ligament as seen from the radiocarpal space. No incongruency of carpal alignment in the midcarpal space. Attenuation or hemorrhage of interosseous ligament as seen from the radiocarpal space. Incongruency or step-oﬀ of carpal space. There may be slight gap (less than width of probe) between carpal bones. Incongruency or step-oﬀ of carpal alignment as seen from radiocarpal and midcarpal space. Probe may be passed through gap between carpal bones. Incongruency or step-off of carpal alignment as seen from radiocarpal and midcarpal space. There is gross instability with manipulation. 2.7-mm arthroscope may be passed through gap between carpal bones.

II III IV

Geissler WB, Freeland AE, Saroie FH, et al., Intracarpal Soft-tissue lesions associated with an intra-articular Fracture of the distal end of the radius. J Boint Joint Surg 1996;78A(3):357–65.

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Fig. 3. Evaluation of the midcarpal joint in this 27-year-old male shows (A) a step off between the lunate (L) and triquetrum (T) in addition to (B) a drive through sign at the LT ligament with total disruption of the dorsal component.

found that 59% of patients with unilateral wrist symptoms and an LT tear on arthrography had similar arthrographic ﬁndings in the asymptomatic wrist [36]. The results of arthrography therefore must be correlated with clinical examination ﬁndings. A videotaped arthrogram with motion sequences in ﬂexion–extension and radial–ulnar deviation can further conﬁrm the presence of an LT injury by demonstrating abnormal pooling of the dye column and of abnormal proximal row kinematics as previously described [37,38]. Videoﬂuoroscopy is useful in demonstrating the site of a clunk that occurs with deviation. In LT sprains this occurs with a sudden catch-up extension of the triquetrum as the wrist moves into maximal ulnar deviation. Other imaging studies may be useful at times. Technetium 99c-MDP bone scans can help identify the site of acute injury, but are less speciﬁc than arthrography [29]. They may prove helpful in cases in which standard ﬁlms and motion studies are negative. MRI technology is not yet reliable for LT ligament imaging [39]. Wrist arthroscopy can be used for diagnosis and treatment in cases of LT injury [40–42]. Arthroscopic inspection may be the best means of assessing instability and ligament disruption.

Fig. 4. Several incisions for LT ligament repair or reconstruction can be used. A curvilinear incision distal to the ulnocarpal articulation is preferred.

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Fig. 5. The extensor retinaculum is divided over the extensor pollicis longus and retinacular ﬂaps are developed by dividing the septae of the second through ﬁfth extensor compartment, exposing the dorsal wrist capsule and structures.

In the authors’ experience, arthroscopy has provided the most accurate means of diagnosis of LT pathology and may replace all other diagnostic studies.

Treatment Choosing the optimal treatment of LT injury requires consideration of several factors. These include the amount of instability (static versus dynamic), the elapsed time between injury and treatment, and the presence of associated injury or degenerative changes. Symptoms of pain in LT attenuations or tears may be caused by dynamic instability or local synovitis [5]. Some investigators have recommended cast and splint immobilization as the initial management of all acute and chronic tears [8,22,24,29,31]. Careful molding with a pad underneath the pisiform maintains optimal alignment as healing progresses. In acute and chronic dissociation (ie, those demonstrating a VISI collapse) and chronic tears unresponsive to conservative management, operative correction is indicated. The goal of surgical intervention is the realignment of the lunocapitate axis and re-establishment of the rotational integrity of the proximal carpal row [9,43]. A variety of procedures have been described, including LT arthrodesis, ligament repair, and ligament reconstruction. In situations in which there is concomitant ulnar negative or positive variance or midcarpal or radiocarpal arthrosis, additional procedures such as ulnar

Fig. 6. The dorsal scaphotriquetral (DST) and dorsal radiotriquetral (DRT) ligaments are identiﬁed and an arthrotomy is made in line with their ﬁbers to create (A) a capsular ﬂap, exposing (B) the midcarpal and radiocarpal joints.

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Fig. 7. When LT ligament repair is performed, the ligament remnant is freshened and the side of the avulsion from the triquetrum is abraded to bone with a burr or rasp. Three to four parallel holes are made using 0.028-in Kirschner wires.

lengthening or shortening, midcarpal arthrodesis, or proximal row carpectomy may be indicated. Total wrist arthrodesis may be indicated in cases in which degenerative changes make other salvage procedures impossible. Repair of the LT ligament has been described by several investigators [8,44,45]. Reagan [8] demonstrated good results, as did Shin et al [46]. The LT interosseous ligament is reattached to the site of its avulsion, generally to the triquetrum. If the palmar ligament is also disrupted, a combined dorsal and palmar approach may be necessary. Augmentation of the repair by dorsal capsulodesis and dorsal ligament repair also may be of some value. Protracted immobilization is necessary as for SL ligament repairs. Patients with strenuous pursuits, chronic instability, or poor quality LT ligament may be best managed by ligament reconstruction. Ligament reconstruction with a tendon graft is also useful. This technique, although demanding, has yielded uniformly good results in two studies, unlike SL ligament

Fig. 8. Two to three sets of nonabsorbable suture are passed through the holes from the ulnar side of the triquetrum. A horizontal mattress suture is placed, starting at the palmar aspect of the ligament remnant. The suture is next passed through the adjacent hole.

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Fig. 9. The use of a 4-0 Prolene on a Keith needle may assist with passage of the sutures through the drill holes. The blunt side Keith needle is passed through the bone hole and a loop of Prolene is created. The ligament suture end is placed through the Prolene loop and the Keith needle is withdrawn, drawing the ligament suture through the bone hole.

Fig. 10. (A) The lunate and triquetrum are held reduced, and percutaneously K-wires are placed to hold the reduction. (B) Radiographs are used to conﬁrm reduction and wire position. (C) The ligament repair sutures are tied and the dorsal radiotriquetral ligament portion of the capsular ﬂap is sutured to the repair, providing additional augmentation to the repair. The remainder of the capsular ﬂap is repaired and the extensor retinaculum is re-approximated, transposing the extensor pollicis longus tendon dorsal to the retinaculum.

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reconstruction [8,44,46]. Reconstruction preserves LT motion and provides the optimal chance for restoration of normal carpal interactions, unlike LT arthrodesis. The observation of asymptomatic congenital LT coalitions and little relative motion between the lunate and triquetrum lead to the concept of LT arthrodesis [47]. LT arthrodesis may be technically less demanding than ligament reconstruction or repair and has become the technique of choice of many investigators. The reported nonunion rate for this procedure, however, is up to 57% [8,44,48–52]. Use of Kirschner wires has been shown to result in an unacceptably high nonunion rate of 47% [50]. Use of compression screws may improve results, but nonunion remains a signiﬁcant problem. A 9% nonunion rate has been reported with the Herbert screw, but conventional cortical screws may exhibit nonunion rates as high as 57% [50–52]. Ulnocarpal

Fig. 11. Final radiographs illustrating bone anchor technique. (A,B) Two bone anchors are used in place of drill holes. (C) The anchors allow for reattachment of the LT ligament to the triquetrum and also allow for dorsal reeﬁng of the dorsal radiocarpal and intercarpal ligaments. (C) Position of sutures before ligament reconstruction and capsular closure.

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Fig. 11 (continued )

impingement required additional surgery in 22.7% of LT arthrodesis patients in Shin’s series [46]. This complication was not seen in LT repair or reconstruction. A comparison of results following arthrodesis, ligament repair, and reconstruction at the authors’ institution [44,46] has led the authors to prefer LT ligament repair or reconstruction. The technique of ligament repair and reconstruction is discussed later.

Technique An arthroscopic evaluation of the radiocarpal and midcarpal joints is performed and LT instability is conﬁrmed. Any associated injury is noted for arthroscopic or open repair. The LT

Fig. 12. When performing a ligament reconstruction, a distally-based strip of extensor carpi ulnaris (ECU) tendon is harvested without disruption of the ECU subsheath. (A) A 2-cm transverse incision is made in the ECU sheath 6 cm proximal to the ulnar styloid. (B) A 4-mm radial slip of ECU is raised, and a 28-gauge wire is tied to the end of the tendon slip. (C) The ECU sheath is opened at the level of the carpometacarpal joint, and the wire is looped and passed through the proximal sheath opening into the distal opening. (D) The wire is pulled distally, creating a distally-based tendon graft.

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Fig. 12 (continued )

ligament is best visualized from the 4-5 or 6R portal. It is essential that dorsal, volar, and membranous portions of the LT ligament are visualized and palpated with a probe to ascertain the integrity of the ligament. Midcarpal arthroscopy is the key to assessing the stability of the LT joint [53]. From the midcarpal perspective, the normal LT joint is smooth, without a step off or diastasis [54]. Placement of a probe into the LT allows one to assess for any dynamic instability. The degree of ligament injury is classiﬁed by the arthroscopic classiﬁcation of tears of the intracarpal ligaments, as described by Geissler (Table 1) [55]. In addition to inspection of the LT joint, the articular surfaces of the hamate, triquetrum, capitate, and lunate should be inspected for arthritic changes (Fig. 3). Following arthroscopy, a curvilinear incision is made distal to the ulnocarpal articulation (Fig. 4). The dorsal branch of the ulnar nerve is identiﬁed and protected. The extensor retinaculum is divided over the extensor pollicis longus, developing retinacular ﬂaps by division of the septae over separating the second through the ﬁfth extensor compartments (Fig. 5). A posterior interosseous neurectomy is performed to partially denervate the dorsal wrist capsule. The dorsal radiotriquetral and scaphotriquetral (dorsal radiocarpal and intercarpal) ligaments are identiﬁed and a capsulotomy made, as described by Berger and Bishop (Fig. 6) [56]. The midcarpal and radiocarpal joint surfaces are exposed and examined for arthritic changes. The SL and LT ligament are examined thoroughly. For open primary LT repair there are two options. The ligament can be reconstructed through drill holes or with the aid of suture anchors. The bone hole technique proceeds as follows. The ligament remnant is freshened and the site of avulsion from the triquetrum is prepared by abrading the bone surface. Three to four parallel holes are placed in this side, exiting dorsally using a 0.028-in Kirschner wire (Fig. 7). Two to three sets of nonabsorbable sutures (3-0) are passed through the drill holes into the lunotriquetral ligament and back through the drill holes (Fig. 8). A Keith needle with 4-0 Prolene suture assists with the placement of the suture through the drill holes (Fig. 9). Two to three 0.045-in Kirschner wires are passed percutaneously through the triquetrum and lunate in a reduced position. Radiographs then conﬁrm proper carpal alignment and pin placement. The nonabsorbable sutures then are tied (Fig. 10) and the dorsal radiotriquetral ligament portion of the capsular ﬂap sutured to the repair, providing additional augmentation. The remaining capsular ﬂap is repaired and the extensor retinaculum reapproximated with absorbable sutures, transposing the extensor pollicis longus tendon dorsal to the retinaculum. If a suture anchor is to be used, it is placed over the dorsal surface of the triquetrum (Fig. 11). K-wires are passed transcutaneously through the triquetrum and into a reduced lunate. Once

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Fig. 13. (A) K-wires are placed in the triquetrum and the lunate to act as guides for drill hole placement. (B) The wires should enter the LT joint at its volar aspect and should exit at the same level.

the joint is reduced, the sutures are passed through the LT ligament and tied down to the triquetrum. The sutures are left long and then used to secure the capsular ﬂap back down to the triquetral ridge, re-establishing the attachment for the dorsal intercarpal ligament. The K-wires are removed at 8 weeks (see Fig. 11). Volar repair may be required if the triquetrum is signiﬁcantly supinated in relation to the lunate or if the volar ligament has sustained a signiﬁcant tear as in a perilunate dislocation. When a ligament reconstruction is required, the LT ligament is sharply de´brided and any synovial tissue is removed. A distally based strip of extensor carpi ulnar (ECU) tendon may be harvested without disrupting the extensor carpi ulnaris subsheath as follows (Fig. 12). A 2-cm transverse incision is made in the ECU sheath 6 cm proximal to the ulnar styloid. A 4-mm radial slip is raised. A piece of 28-gauge wire is tied to the end of the tendon graft. The ECU sheath is next opened at the level of the carpometacarpal joint and the wire is looped and passed through the sheath into the distal opening. It is gently pulled distally, creating a distally-based tendon graft. The graft then is passed palmar to the extensor retinaculum into the joint. The 28-gauge wire is left tied to the end of the graft and a moist sponge is wrapped around the graft while the bone tunnels are prepared. A 0.045-in Kirschner wire is placed in the triquetrum from its dorsal ulnar corner to enter the LT joint at its volar radial aspect. A second 0.045-in Kirschner wire is placed in the lunate from the mid dorsal radial border entering the LT joint at the same level (Fig. 13). If a static deformity exists, it is important to place the Kirschner wires with the deformity reduced. Joysticks in the scaphoid and triquetrum are useful to maintain the reduction while the lunate and triquetral wires are placed. The position of the wires is checked to conﬁrm the ability to safely enlarge the drill holes without fracture. The tunnels are created using a series of sharp awls, gradually increasing the diameter of the awls until a 5-mm tunnel is created in the lunate

Fig. 14. Bone tunnels are created using a series of graduated sharp awls, increasing the diameter of the tunnels to 5 mm. Care must be taken to prevent carpal fractures during tunnel creation.

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and the triquetrum (Fig. 14). The wire previously secured to the end of the graft is looped and passed through the triquetral tunnel toward the lunate. An arthroscopic probe is useful to hook the wire loop and pull it through the lunate bone tunnel. The wire is used to pass the tendon graft through the tunnels (Fig. 15). While maintaining tension on the tendon graft, the lunate and triquetrum are reduced, and two 0.045-in Kirschner wires are passed percutaneously across the LT joint. Reduction, pin position, and length are checked with radiograph (Fig. 16). The tendon graft then is tied to itself on the dorsum of the lunate and triquetrum with nonabsorbable suture (Fig. 17). Excess tendon is trimmed and the wound is irrigated with normal saline solution. The wound is closed as previously described in the ligament repair section.

Complications Complications can be minimized by careful attention to detail. This includes protection of the dorsal sensory branch of the ulnar nerve (DSBUN), correction of the VISI deformity before ligament repair or reconstruction, and care in creation of bone tunnels. The only complication seen postoperatively in Shin et al’s review of reconstruction was DSBUN neuritis, and of repairs, there was a 14.8% failure rate (secondary to recurrent injury) and DSBUN neuritis [46].

Rehabilitation Active and passive range of motion (ROM) exercises of the ﬁngers, elbow, and shoulder and anti-edema measures may begin immediately. The postoperative dressing and sutures are

Fig. 15. The tendon graft then is passed through the bone tunnels. This is facilitated by passing a looped end of the wire previously secured to the end of the tendon graft into the triquetral bone tunnel toward the lunate. (A) An arthroscopic probe is placed through the lunate tunnel, and the wire loop is hooked and pulled through the lunate. (B) The wire is gently pulled and the graft passed through the bone tunnels. (C) Graft (arrow) passed through bone tunnel in triquetrum (T) and lunate (L). Small arrow points to retained capsular ﬂap.

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Fig. 16. K-wires are percutaneously placed across the reduced LT joint and conﬁrmed by radiographs.

removed 10–14 days postoperatively, and a long arm cast in neutral forearm rotation is placed for 6–8 weeks. The pins are removed at 8–10 weeks following ligament repair and the wrist is supported with a splint during the rehabilitation period. Strengthening exercises are begun once ROM has returned. The wrist can be supported with a splint during activities for an additional 3–6 months. Longer periods of immobilization have been recommended and may be beneﬁcial in

Fig. 17. The tendon graft is tied to itself on the dorsum of the triquetrum with nonabsorbable suture. (A) Excess graft is trimmed and the capsular ﬂap is repaired and the extensor retinaculum reapproximated, transposing the extensor pollicis longus tendon dorsal to the retinaculum. (B) Capsule is closed before retinacular reconstruction.

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more severe injuries, though there are no good long-term studies examining postoperative immobilization patterns in LT injuries; however, postoperative stiﬀness has been correlated with successful outcomes [40,46,57,58]. Pins are removed 8–12 weeks following ligament reconstruction and gentle ROM of the wrist is initiated with periodic splinting for an additional 8 weeks. Strengthening and increasing ROM exercises continue during this period. Repair of the LT ligament has been described by several investigators [37,44,45]. Reagan [8] demonstrated good results, as did Shin et al [46]. Eighty percent of patients were satisﬁed with their outcome. In the only comparative study of LT arthrodesis, repair, and reconstruction, LT repair and reconstruction were found to be superior to LT arthrodesis with respect to patient satisfaction, complication rates, and reoperation rates [46]. In this study, overall complication rates for LT fusion was 81.2%, whereas it was 40.7% for repair and 25% for ligament reconstruction. Open LT repair or reconstruction remains the authors’ treatment of choice for LT instability.

Summary Treatment of LT injuries remains controversial and many surgical options are available. Based on the authors’ experience and that of the literature, the authors prefer ligament repair or reconstruction rather than LT arthrodesis. Although surgical repair or reconstruction can be technically challenging, it preserves LT motion and provides the optimal chance for restoration of normal carpal interactions.

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Lunotriquetral arthritis and ulnar impaction syndrome Randip R. Bindra, MD, FRCSa,*, Joseph F. Slade, III, MDb a

Center for Hand and Upper Extremity Surgery, University of Arkansas for Medical Sciences, 4301 West Markham, Slot 531, Little Rock, AR 72205-7199, USA b Hand and Upper Extremity Center and Microvascular Surgery, Department of Orthopaedics, Yale University School of Medicine, New Haven, CT, USA

Ulnar impaction syndrome is a common cause of ulnar-sided wrist pain that eventually leads to arthritis of the lunotriquetral joint. Ulnar impaction syndrome results from increased loading of the ulnocarpal articulation and usually is associated with a positive ulnar variance. The increased loading of the ulnocarpal joint leads to degeneration and perforation of the triangular ﬁbrocartilage complex (TFCC). Chondromalacic changes develop on the opposing surfaces of the lunate and triquetrum distally and the ulnar head proximally. A disruption of the lunotriquetral ligament follows, with lunotriquetral arthritis the end result. The condition ﬁrst was described by Milch [1] as a cause of wrist pain after malunion of a radius fracture; various terms since have been used to describe this symptom complex, including ulnocarpal abutment, ulna abutment, ulnocarpal impingement, and ulnar carpal loading. Ulnar impingement is a different clinical condition that is seen after excision of the distal ulna and results from the impingement of the ulnar stump against the radial shaft [2]. The most common cause of ulnar impaction syndrome is a relatively longer ulna referred to as positive ulnar variance. This may be a congenital anomaly or can occur as a dynamic phenomenon during forceful gripping of the wrist in a pronated position. A relative lengthening of the ulna also can result from injury or other pathologic processes that cause shortening of the radius. This article explains the etiopathogenesis of ulnar impaction syndrome and discusses the clinical features and management of the lunotriquetral joint dysfunction that eventually results in chronic cases. The techniques for ulnar recession, which is the mainstay in management of this condition, are described in detail.

Surgical anatomy One characteristic of the human wrist is the lack of articulation between the ulna and the carpus that is seen in primates. Phylogenetic regression of the ulna is an important step in primate evolution that allows increased mobility of the hand and the forearm [3]. With evolution of the wrist, a ﬁbrocartilaginous disk joins the distal articular surface of the radius to form an articulation with the proximal row of the carpus instead of its direct articulation with the ulnar head. The distal ulna articulates with the sigmoid notch of the radius on its radial aspect and the triangular ﬁbrocartilage on its distal aspect. The ﬁbrocartilaginous disk that is interposed between the ulna and the proximal carpal row is part of a complex ligamentous structure that

* Corresponding author. E-mail address: [email protected] (R.R. Bindra). 1082-3131/04/$ - see front matter Ó 2004 Elsevier Inc. All rights reserved. doi:10.1016/S1082-3131(03)00072-4

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arises from the radius and inserts into the distal ulna and the ulnar carpus and more appropriately is referred to as the TFCC. This complex inserts into the ulnar carpus all the way up to the base of the ﬁfth metacarpal [4]. The ﬁbrocartilage disk and its complex provide a ﬂexible yet strong restraint to permit rotational movement of the radiocarpal complex on the axis of the ulnar head. The ﬁbrocartilage disk itself is biconcave, conforming to the convex dome of the head proximally and the convex articular surfaces of the lunate and triquetrum distally. The peripheral margins of the disk have a linear arrangement of thickened collagen, often referred to as the dorsal and palmar radioulnar ligaments. The capsule of the distal radioulnar joint is thin in most parts but is reinforced dorsally by the subsheath of the extensor carpi ulnaris tendon, providing the complex with an insertion extending to the base of the ﬁfth metacarpal. The lunotriquetral articulation on the ulnar side of the carpus is stabilized by two interosseous ligaments, palmar and dorsal, running transversely between the two bones. The rest of the articulation is closed by a ﬁbrocartilaginous membrane proximally. The ulnolunate and ulnotriquetral ligaments fan out from their origin at the ulna styloid to insert on the palmar aspect of the lunate and triquetrum. These ligaments blend intimately with the ﬁbrocartilage disk on its volar surface. In the most superﬁcial plane lies another extrinsic ulnocarpal ligament, which courses obliquely from the palmar edge of the triangular ﬁbrocartilage disk to attach to the neck of the capitate and has been termed the ulnocapitate ligament [5]. Clinical signiﬁcance of the relative length of the radius and ulna ﬁrst was brought to attention when Hulte´n [6] described the frequent association of negative ulnar variance with Kienbo¨ck’s disease. A database of posterior and anterior radiographic measurements of the normal wrist found the mean ulnar variance is ÿ0.9 mm (range ÿ4.2–+2.3 mm) [7]. Mechanics of the ulnocarpal joint The TFCC provides the functions of a continuous gliding surface for articulation of the proximal carpal row, a stabilizing mechanism to allow rotational movements of the forearm, support to the ulnar carpus through ulnocarpal supporting ligaments, and a cushion that bears the load transmitted onto the distal ulna [8]. Experimental studies showed that 82% of the static axial load across the wrist is borne by the radius, and only 18% of the load is transmitted through the ulna. The compressive force across the ulnocarpal articulation is transmitted partially through the center of the triangular ﬁbrocartilage disk to the ulnar dome. Compressive loading also has a tendency to separate the radius and ulna, resulting in the generation of a tensile force within the peripheral ﬁbers of the triangular ﬁbrocartilage [8]. Experimental changes in the relative length of the radius and ulna result in signiﬁcant alterations in loading of the ulna. A 2.5-mm increase in ulnar length increases the load on the ulnar side of the wrist to 42%, whereas shortening by the same amount decreases the loading to 4.3% [9]. Etiology Cadaver studies suggest that degenerative central disk perforations are present in about 20% of wrists [10]. Two thirds of cadaver specimens showed associated degenerative changes in the ulnar head and ulnar half of the lunate. In another cadaver series, 73% of wrists with neutral or positive ulnar variance were associated with a central TFCC perforation. In contrast, only 17% had similar changes in the presence of a negative ulnar variance [11]. The experimental demonstration of signiﬁcant changes in the ulnar load with relatively small changes in length of the ulna provided further indirect evidence of the causal relationship between ulnar-positive variance and ulnar impaction syndrome. Reports of clinical series concur with anatomic studies with regard to progressive degenerative changes in the triangular ﬁbrocartilage and the corresponding surfaces of the ulnocarpal articulation in ulnar-positive wrists. Finally, resolution of symptoms and restoration of function have been reported by various authors after treatment of this condition by ulnar shortening [12–17]. The etiology of ulnar-positive variance includes congenital occurrence, pathologic radial shortening, and dynamic ulnar plus variance. There is a range of ulnar variance in the population,

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and some wrists are normally ulnar positive. In other instances, relative ulnar lengthening develops as a result of pathologic shortening of the radius. This pathologic shortening is seen most commonly after fractures of the distal radius that heal with collapse. Excision of the radial head in conjunction with disruption of the interosseous membrane also can lead to proximal migration of the radius, resulting in a longer ulna at the wrist. Premature closure of the distal radius epiphysis due to injury or infection is another common etiologic factor of radial shortening and is seen in children. Premature physeal closure of the distal radius after gymnastic activity also has been reported as a cause of ulnar impaction in teenaged gymnasts [17].

Pathogenesis The advent of wrist arthroscopy has allowed better understanding of the pathologic changes that occur in ulnar impaction. Palmer [18] classiﬁed these changes in the TFCC. An increased load on the ulnocarpal joint leads to wear of the horizontal portion of the TFCC with the appearance of ﬁbrillation. With continuing impaction, the adjacent cartilage surfaces of the ulnar head, lunate, and triquetrum begin to develop changes of chondromalacia. With the progressive ‘‘drilling effect’’ of the distal ulna against the triangular ﬁbrocartilage, a central perforation of the triangular ﬁbrocartilage disk results [19]. A high proportion of wrists with chronic impaction develop attenuation leading to rupture of the lunotriquetral ligament. In the ﬁnal stages of ulnar impaction, the loss of the cushioning disk, lunotriquetral instability, and chondromalacia of the articulating surfaces lead to degenerative arthritis of the lunotriquetral and distal radioulnar joints (Fig. 1). Rarely, ulnar impaction may result from abnormal contact between the ulnar styloid and the triquetrum in extremes of wrist extension, supination, and ulnar deviation. This abnormal contact would occur due to an abnormally long ulnar styloid. The clinical incidence of such

Fig. 1. Diagrammatic representation of the pathologic changes seen in chronic ulnar impaction syndrome. Central wear in the TFCC results in a perforation that is followed by chondromalacia of the ulna and cystic changes in the adjacent carpus. Attrition rupture of the lunotriquetral interosseous ligament and arthrosis of the lunotriquetral and distal radioulnar joints eventually occur.

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‘‘stylocarpal impingement’’ is not known, but it has been postulated to play a role in some traumatic fractures of the triquetrum [20].

Clinical features Clinical ﬁndings in ulnar impaction syndrome depend on the severity of the condition. In early cases, patients complain of ulnar-sided wrist pain related to strenuous activity or repetitive use, with relief at rest. Weakness of grip is an early complaint because pain from the impaction precludes making a strong ﬁst. In late cases, the pain is more persistent, and some loss of motion, ﬁrst in the pronation-supination arc and then in the ﬂexion-extension arc, is inevitable. Typically the symptoms start insidiously and progress slowly without any preceding signiﬁcant injury. Careful clinical examination is essential to distinguish ulnar impaction syndrome from other causes of ulnar-sided wrist pain. In early cases, routine examination of the wrist may be normal, and it is necessary to stress the ulnocarpal articulation to reproduce the symptoms of ulnarsided pain. With the forearm in full pronation, the examiner holds the ulna down with a thumb and places the wrist in maximal ulnar deviation [17]. The forearm is rotated into supination, while maintaining the wrist in ulnar deviation. The ulnar impaction test is positive if forearm rotation is painful throughout the arc of rotation and the pain persists into full supination. The test also has been termed the ulnocarpal stress test, and other authors have shown its clinical usefulness [21]. Although a sensitive test, the ulnar impaction test is not speciﬁc to ulnocarpal impaction and is also positive after traumatic tears of the TFCC and lunotriquetral ligament. With advanced pathology, tenderness over the TFCC, ulnar head, and lunotriquetral articulation is elicited easily. A positive lunotriquetral shuck indicates advanced impaction with lunotriquetral instability. Loss of motion of the wrist and forearm occurs late, but weakness in grip is an early objective ﬁnding.

Investigations Routine radiography Wrist radiographs need to be obtained in a standardized fashion to eliminate errors in measurement of ulnar variance. To obtain posteroanterior and lateral radiographs, the shoulder is placed at 90 abduction, the elbow is placed at 90 ﬂexion, and the forearm is kept in a neutral position. The x-ray beam is centered over the radiocarpal joint. Standardized positioning is essential because ulnar variance has been shown to increase with pronation and decrease with supination of the forearm [21]. Ulnar variance is the distance between the tangent to the top of the dome of the ulnar head and the distal edge of the sigmoid notch of the radius on a posteroanterior projection. Assessment of variance by using a template of concentric circles simulates the curvature of the proximal carpal row and provides a measurement that may be clinically more meaningful [11]. If the clinical diagnosis is not supported by radiography, and neutral variance is seen on static ﬁlms, a pronated grip radiograph of the wrist may be helpful to assess for dynamic ulnar-positive variance [22]. With advancing pathology, the adjoining surfaces of the lunate and ulna show cystic lesions. In long-standing and severe cases with complete perforation of the TFCC, the ulnocarpal articulation shows degenerative changes with osteophyte formation and sclerosis of the articulating surfaces. Wrist radiographs also are essential in the identiﬁcation of abnormalities of the distal radius, such as shortening from a previous radius fracture or premature closure of the distal radius epiphysis. Arthrography Wrist arthrography is useful in the diagnosis of perforation of the TFCC and has been shown to have a 90% correlation with arthroscopy [23]. A wrist arthrogram cannot evaluate the size of the TFCC tear, however, or the clinical signiﬁcance. A wrist arthrogram shows leakage

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of dye through the lunotriquetral joint in cases of advanced ulnar impaction syndrome with rupture of the lunotriquetral interosseous ligament. When looking for interosseous ligament tears, three portal wrist arthrograms are recommended because the ﬂow through of dye from one compartment to the other may be blocked by synovitis, leaving some tears undiagnosed [24,25]. Bone scintigraphy Radionuclear bone scanning is a useful screening tool when the examiner fails to localize wrist pathology after clinical examination [26]. A three-phase technetium-99m scan shows a diffuse area of increased isotope accumulation on the ulnar side of the wrist (Fig. 2) [21]. A positive test can localize pathology to the ulnar side of the wrist but cannot identify the nature of the pathology. A negative test also is useful because only 5% of wrists with normal uptake have any identiﬁable pathology [26]. Magnetic resonance imaging High-resolution MRI has been shown to be eﬀective in the evaluation of TFCC tears, with a sensitivity of 0.89, a speciﬁcity of 0.92, and an accuracy of 0.90 compared with arthroscopy and arthrotomy [27]. Marrow edema in the ulnar aspect of the proximal lunate appears as an area of low signal intensity on T1-weighted coronal images (Fig. 3) [28]. MRI also is helpful in the differentiation of Kienbo¨ck’s disease from ulnar impaction in some cases with marked cystic changes in the lunate. The addition of contrast arthrography to MRI can help to increase the sensitivity of detection of triangular ﬁbrocartilage and lunotriquetral ligament tears. Computed tomography CT of the distal radioulnar joint permits a more accurate assessment of the geometry of the articular surfaces. CT also is helpful in detection of early distal radioulnar joint degenerative

Fig. 2. Technetium-99m bone scan shows increased uptake over the ulnocarpal articulation in a patient with ulnar impaction syndrome.

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Fig. 3. MRI changes with ulnar impaction syndrome. T1-weighted image (left) shows loss of the bright marrow signal on the ulnar corner of the lunate. This area is bright on the T2-weighted image (right), suggesting the changes are due to marrow edema. The well-demarcated and localized changes differentiate it from Kienbo¨ck’s disease. Note the thinning of the TFCC in both images.

changes with formation of osteophytes. CT provides a more accurate method of assessment of the ulnar variance. Arthroscopy Arthroscopy allows conﬁrmation of the diagnosis, staging of severity, and the option to proceed with therapeutic procedures, such as de´bridement of the joint or recession of the ulna [23]. Patients with ulnar impaction usually have a long-standing history of wrist pain without history of preceding signiﬁcant trauma. The symptoms are gradually progressive, and complaints include weakness and restriction of motion either in rotation or in ﬂexion-extension arcs; sometimes there are complaints of a click on the ulnar side of the wrist. Physical examination does not reveal any distal radioulnar joint instability on forearm rotation, but the symptoms can be elicited with pain on ulnocarpal stress testing. Routine standardized wrist radiographs are helpful in most cases and establish the diagnosis with the conﬁrmation of ulnarpositive variance in most cases. A pronated-grip radiograph shows dynamic ulnar-positive variance in other cases. In addition, a plain radiograph may show cystic changes on opposing surfaces of the lunate and the ulna. If the symptoms are inconsistent, and it is not possible to localize the source of pain on clinical examination, a bone scan is indicated. If further evaluation is needed, magnetic resonance arthrography helps to detect tears of the lunotriquetral interosseous ligament or the triangular ﬁbrocartilage. Treatment Nonoperative treatment may be eﬀective in controlling symptoms in patients with early ulnocarpal impaction. Conservative methods include splinting of the wrist to prevent ulnar deviation, nonsteroidal anti-inﬂammatory drugs, and activity restriction. A steroid injection into the ulnocarpal joint can reduce the discomfort from the associated synovitis. Surgery to decompress the ulnocarpal joint may be considered with recurrence of symptoms after a conservative trial or in advanced cases in which conservative treatment does not provide any signiﬁcant lasting relief. Decompression of the ulnocarpal articulation is achieved either by

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recession or by removal of the distal ulna, and the choice of operation depends on congruency and status of the cartilage of the distal radioulnar joint. Ulnar recession can be performed by an extra-articular procedure in which a segment of ulnar shaft is removed or directly at the joint by taking oﬀ a ‘‘wafer’’ from the distal ulnar articular surface. If the ulnar impaction is secondary to shortening of the radius, it is more appropriate to consider correction of the radial length ﬁrst. Ulnar shortening In 1941, Milch [1] proposed ulnar shortening as an alternative to excision of the distal ulna for the treatment of distal radioulnar joint derangement. He presented a case of ulnocarpal impaction after radius fracture. He obtained successful relief of symptoms and improvement in appearance by performing an extraperiosteal resection of an oblique portion of the distal ulnar shaft and ﬁxation of the ulna with a wire suture. With the advances in internal ﬁxation techniques over the subsequent decades, the principle of resection of a segment and rigid internal ﬁxation of the ulna became a popular technique for the treatment of ulnar impaction. One of the earliest series of ulnar impaction reported successful treatment with a transverse ulnar shortening osteotomy and plate ﬁxation in 31 cases. The average time of healing of 3.4 months with only one nonunion established diaphyseal shortening of the ulna as a useful surgical procedure [29]. Since then, several authors have used similar principles but modiﬁed the technique to create an oblique osteotomy and achieve compression by ﬁxation with a compression plate and interfragmentary compression screw. Although an oblique osteotomy is technically more challenging than a transverse osteotomy, it has the advantage of providing a larger surface area for healing and allows insertion of an interfragmentary compression screw, which increases the stability of the construct by reducing the working distance of the plate. Biomechanically an oblique osteotomy of the ulna with internal ﬁxation is signiﬁcantly stiffer in torsion than a transverse osteotomy [16]. Specialized cutting guides that allow the excision of precise segments of bone and permit predrilling screw holes to facilitate ulnar ﬁxation have been developed and described by several authors [15,16,30]. These jigs can help to expedite surgery by providing technical assistance but are not essential for osteotomy and ﬁxation of the ulna. Surgical technique The principle of surgery is to achieve shortening of the ulna by creating an oblique osteotomy to remove the appropriate-sized segment and allow stabilization using a dynamic compression plate and an interfragmentary compression screw. It is important to understand the geometry of an osteotomy (Fig. 4). When bone is cut with a saw, a small amount of bone is lost corresponding to the blade thickness and is referred to as kerf. If a segment of bone is excised, there is an additional loss of bone due to the kerf of each saw cut. In addition, if the osteotomy is made in an oblique fashion, the linear shortening obtained is greater than the bone removed by a factor of the cosine of the angle of the cut [31]; this must be taken into consideration when planning the width of the excised fragment in relation to the desired amount of shortening. The procedure is performed under general or regional anesthesia. The patient is positioned supine, and the arm is placed on a hand operating table. After application of an exsanguinating tourniquet, the skin incision is made on the subcutaneous border of the distal third of the ulna and is planned 2 cm longer than the selected plate. The incision must not extend beyond the distal radioulnar joint. The interval between the extensor carpi ulnaris and ﬂexor carpi ulnaris tendons is developed to expose the bone. In the distal third of the incision, care is taken to preserve any branches of the dorsal cutaneous division of the ulnar nerve. To avoid devascularization of the ulna, the periosteum around the ulna should be preserved during exposure of the bone. Hohmann retractors are placed on either side of the ulna, and the volar surface of the ulna is exposed. This surface provides a suitably ﬂat area for plating and reduces the possibility of irritation seen with plates positioned on the subcutaneous surface of the ulna. A six-hole 3.5-mm AO dynamic compression plate or a low-contact dynamic compression plate is selected and placed against the volar surface of the bone as far distally along the shaft as possible. The osteotomy is planned to lie beneath the third hole of the plate. The plate is

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Fig. 4. Geometry of an oblique osteotomy. The linear shortening achieved is larger than the thickness of the fragment excised as a result of the kerf of the saw blade and the obliquity of the cut.

removed and pretensioned by producing a slight ‘‘overbend’’ in the plate. This is necessary to prevent gapping of the osteotomy at the cortex opposite the plate after ﬁnal ﬁxation. A 1-cm cuﬀ of periosteum is excised circumferentially around the planned osteotomy site. The plate is replaced on the volar surface of the ulna and held with bone-holding forceps. The most distal hole of the plate is drilled in a neutral position, and the appropriate length screw is inserted to ﬁx the plate to the distal fragment of the ulna. After alignment of the plate along the long axis of the ulna, a second drill hole is placed in the second most distal hole, and the screw length is measured. No screw is inserted at this time. Using the tip of the electrocautery, the osteotomy is marked beneath the third plate hole at 45 to the long axis of the shaft. A linear mark also is made alongside the plate to ensure correct rotational alignment of the bone when the osteotomy is completed (Fig. 5A). The plate is removed to allow creation of the osteotomy. Using an oscillating saw with constant irrigation, a 45 oblique osteotomy is made starting on the volar cortex distally and aiming toward the dorsal cortex in a proximal direction. The osteotomy is completed through three quarters of the bone only to allow orientation of the second saw cut. A saw blade placed in the ﬁrst osteotomy serves as a template to facilitate parallel placement of the second saw cut. A second osteotomy is performed and completed parallel to the previous osteotomy at an appropriate distance proximal to the ﬁrst osteotomy. The remainder of the ﬁrst osteotomy is completed. The resulting segment of bone is excised, and the plate is replaced on the distal fragment and ﬁxed by inserting screws into the two previously drilled holes. The ulna is aligned, the osteotomy is reduced and manually compressed, and the plate is held against the proximal fragment with bone-holding forceps. An eccentric screw is placed in the plate hole in the proximal fragment closest to the osteotomy (Fig. 5B). As the eccentric screw is tightened, compression across the osteotomy gap is noted (Fig. 5C). If closure of the osteotomy gap is achieved, additional screws are inserted in the proximal fragment in neutral positions (Fig. 5D). Final tightening of the screws is not done at this stage. Finally, an interfragmentary compression screw is placed across the osteotomy through the plate hole overlying the osteotomy using lag screw technique. The gliding hole ﬁrst is drilled in the near cortex at an angle bisecting the perpendicular of the long axis of the radius and the perpendicular to the osteotomy using a 3.5-mm drill bit. The 2.5-mm insert drill sleeve is placed within the gliding hole, and the far

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Fig. 5. Steps in performing an oblique ulnar shortening osteotomy. (A) The plate is placed as distal as possible on the volar cortex of the ulnar shaft, ﬁxation of the distal fragment is planned, and a 45 osteotomy is marked in a volar-distal to proximal-dorsal direction. The osteotomy is planned to lie under the third plate hole to allow later placement of an interfragmentary screw. (B) After excision of the bone fragment, the plate is ﬁxed ﬁrst to the distal fragment using the previously drilled holes. A loading (eccentric—away from the osteotomy) hole is drilled in the proximal fragment. (C) Axial compression is achieved as the screw in the proximal fragment is tightened. Correct orientation of the obliquity of the osteotomy is crucial. A reverse obliquity to that shown in the ﬁgure results in loss of reduction when axial compression is applied. (D) The remaining proximal screws are inserted in neutral mode. (E) Final compression and stability is achieved by insertion of an interfragmentary screw through the plate and across the osteotomy.

cortex is drilled using a 2.5-mm drill. The appropriate length 3.5-mm screw is inserted to achieve additional compression of the osteotomy. All screws ﬁnally are tightened to achieve completion of ﬁxation. Before closure, the tourniquet is deﬂated, and hemostasis is obtained. Routine closure is performed with a subcuticular suture to skin. Postoperatively a sugar-tong plaster splint is applied to immobilize the forearm and wrist. The splint is replaced with a removable brace after 3 weeks, when mobilization of the forearm and wrist is begun. Attention to detail is necessary because there are potential pitfalls with this procedure. Correct precontouring and positioning of the plate on the volar surface of the ulna are important. It is important to ensure that both cuts through the ulna are parallel and both surfaces are ﬂat without any jagged edges that would prevent closure of the gap. When the osteotomy is completed and the plate is attached to the distal ulnar fragment, careful reduction of the osteotomy is required before the plate is ﬁxed to the proximal fragment. If the osteotomy gap should remain open after the ﬁrst eccentric screw is placed in the proximal fragment, a second compression screw can be placed adjacent to the ﬁrst in eccentric mode. The ﬁrst screw then must be loosened, while the second screw is fully seated and some closure of the osteotomy is achieved. Tightening the ﬁrst screw provides additional compression of the osteotomy site. The use of an AO compression device usually is not required but is a useful adjunct for closure of gaps larger than 3 mm. It is important that the osteotomy is directed such that the moving proximal fragment is stabilized into the ‘‘axilla’’ between the plate and the bone. Reversal of the osteotomy direction causes the proximal fragment to displace as the eccentric screw is tightened and the osteotomy is compressed. Results and complications Healing of the osteotomy is diﬃcult to assess because callus formation is negligible after rigid internal ﬁxation. Blurring of the osteotomy margins and presence of trabecular bone crossing

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the osteotomy are necessary to deﬁne union of the osteotomy [16]. Average time to union seems to vary with the technique of shortening employed. Reported union time after transverse osteotomy ranges from 13 to 20 weeks and after oblique osteotomy averages 11.4 weeks [16,29]. The application of compression further enhances healing and can reduce the average time to union to 9.7 weeks after a transverse osteotomy and 6 to 8 weeks after an oblique osteotomy [12,32]. The lowest time to union of 4.3 weeks has been reported after step-cut osteotomy of the ulna at its distal metaphysis with wire suture ﬁxation in a series of 11 patients [33]. A step-cut design and metaphyseal location of the osteotomy seem to offer the quickest healing potential. A step-cut osteotomy is technically demanding, however, and stable ﬁxation of the osteotomy close to the ulnar head can be challenging. Nonunion and delayed union are uncommon, especially with oblique osteotomy and rigid internal ﬁxation. Most series report union in all cases or an occasional nonunion [12,16,29,32,33]. Smoking is the single factor that has been observed to affect adversely the outcome of ulnar shortening. Smokers have increased time to union with an average of 28 weeks and a 30% incidence of delayed union and nonunion [34]. When AO 3.5-mm dynamic compression plates are used, more than half of patients subsequently require plate removal [12]. Placement of the plate on the volar cortex deep to the ﬂexor carpi ulnaris may help to reduce the need for subsequent implant removal. Variations in the shape of the distal radioulnar articulation in the coronal plane have led to the suggestion that ulnar shortening may result in incongruity and subsequent arthrosis of the distal radioulnar joint [35,36]. Radiographic degenerative changes without clinical symptoms have been noted in 7 of 25 patients after ulnar-shortening osteotomy [37]. These investigators were unable, however, to show any correlation of the inclination of the distal radioulnar joint with the likelihood of developing degenerative changes postoperatively. Wafer excision of distal ulna An alternative to ulnar shortening is partial excision of the distal ulna—the so-called wafer procedure. The premise of this operation is that the ligament attachments of the TFCC to the base of the styloid process are preserved and the distal radioulnar joint is preserved, while decompressing the ulnocarpal joint. Feldon et al [14] initially described the procedure, and subsequent authors reported favorable results with the wafer procedure [38,39]. A retrospective review comparing the results of the wafer resection procedure with ulnar shortening revealed similar results in terms of pain relief and restoration of function without the complications of delayed union or hardware removal noted with the osteotomy group [39]. The wafer procedure also has been successful in treatment of ulnar impaction syndrome in patients who are ulna neutral or ulna negative [40]. Surgical technique An oblique incision is made on the dorsum of the ulnar side of the wrist, and the incision is developed through the ﬁfth extensor compartment. The dorsal capsule of the distal radioulnar joint is incised using an L-shaped incision. The transverse limb of the incision is made carefully, proximal to the level of the triangular ﬁbrocartilage, then carried vertically downward on its radial aspect close to the radial attachment of the triangular ﬁbrocartilage. If a tear of the triangular ﬁbrocartilage is noted or ﬁbrillation of its undersurface is present, it can be de´brided at that time. A blunt curved freer is passed over the head of the ulna to engage on its palmar surface to protect the triangular ﬁbrocartilage. A narrow osteotome is used to excise a wafer of the ulnar head in a direction perpendicular to the shaft of the ulna. A back-cut through the ulna head just lateral to the base of the styloid allows the wafer to be excised without fracturing the ulnar styloid. The dorsal capsule is repaired with interrupted nonabsorbable sutures. The extensor digiti minimi tendon is replaced, and the extensor retinaculum over it is repaired, if possible. Postoperatively the forearm is immobilized in supination in a long arm splint for 2 weeks until the wound heals, followed by active wrist mobilization. Instability of the distal radioulnar joint has not been reported after this procedure.

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Arthroscopic wafer procedure Another option is to perform the wafer resection of the ulna arthroscopically at the time of arthroscopic de´bridement of a degenerative TFCC (Fig. 6). Arthroscopic resection causes minimal disruption to the capsuloligamentous constraints of the distal radioulnar joint. Early clinical results have been correlated by experimental studies, which have shown that only two thirds of the width of the distal ulnar articular cartilage need be excised to unload the ulnocarpal articulation signiﬁcantly [23,41,42]. Surgical technique After routine radiocarpal and midcarpal arthroscopy, the central perforation of the TFCC is de´brided down to a stable peripheral rim with a shaver introduced through the 6-R portal with visualization from the 3-4 portal. Using a 2-mm powered bur in the 6-R portal, the ulnar head is recessed down from the sigmoid notch by the thickness of the bur beginning radially, then working toward the ulnar styloid. Care is taken not to disrupt the ulnar attachment of the TFCC. While maintaining traction, the forearm is rotated into full pronation to ensure that the ulna is recessed adequately. Visualization of the ulna from the 6-R portal determines the adequacy of recession, which can be conﬁrmed by ﬂuoroscopy. Rehabilitation with range-ofmotion exercises can be started 1 week after surgery. Other procedures Ulnocarpal impaction due to the relatively increased length of the ulna is a common cause of pain after impacted and shortened metaphyseal fractures of the radius. Ulnar shortening may be considered for the treatment of ulnar impaction if shortening of the radius is the main deformity without any signiﬁcant angular misalignment (Fig. 7). Ideally a corrective osteotomy of the radius should be undertaken to correct the three-dimensional deformity of shortening, dorsal angulation, and supination of the distal fragment seen after Colles’ fractures. Shortening of the ulna is a useful procedure, however, especially in elderly patients, in whom radial corrective osteotomy with an opening wedge would be a major undertaking. Signiﬁcant radial shortening also is seen after excision of the radial head for fracture with an unrecognized interosseous membrane injury—the Essex-Lopresti injury. In such cases, the primary treatment of the ulnar

Fig. 6. Posteroanterior wrist radiographs before and after arthroscopic wafer excision procedure. The minimal excision of the distal ulna can be achieved with a bur used through the central perforation of the TFCC.

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Fig. 7. Ulnar shortening for ulnar impaction after distal radius fracture. This procedure should be used only if radial shortening is the main deformity and there is no signiﬁcant dorsal or radial tilt of the distal radius.

abutment syndrome is restoration of radial length; this can be achieved by radial head replacement (Fig. 8). In the presence of degenerative changes or incongruity of the distal radioulnar joint, shortening the ulna does not relieve the pain with forearm rotation. In these cases, arthroplasty of the distal radioulnar joint should be considered. In the Darrach procedure, the ulna is exposed dorsally, and a transverse osteotomy is made at the level corresponding to the proximal

Fig. 8. Ulnar abutment resulting from radial shortening following radial head excision after an unrecognized EssexLopresti injury (top, left and right). The radius length was restored after titanium replacement of the radial head and symptoms were improved (bottom, left and right). An additional procedure for ulnar recession was not required.

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extent of the sigmoid notch of the radius. The distal ulna is excised extraperiosteally, leaving the ulnar styloid process and the attached TFCC intact. The periosteal sleeve is closed to maintain soft tissue tension as much as possible. The Darrach procedure can produce satisfactory results in carefully selected low-demand patients. Instability of the stump of the ulna resulting in ulnar impingement syndrome between the distal stump of the ulna and the radius can be painful and troublesome, however [2]. Surgery to reconstruct the unstable distal ulna is difﬁcult; many procedures have been described with variable results. The premise of hemiresection of the distal ulna is to excise the entire articular surface of the ulnar head, leaving the ulnar styloid and shaft axis intact [43]. Soft tissue interposition of tendon, muscle, or capsule in the space left by excision of the ulnar head is necessary to limit contact of the radius and ulna shafts. If the ulna is excessively long, the ulnar styloid should be excised and reattached to the shortened ulnar stump to avoid the problem of stylocarpal impingement. A prerequisite for the hemiresection interposition technique is an intact or repaired TFCC. The Sauve-Kapandji procedure entails fusion of the distal radioulnar joint and creation of a pseudarthrosis in the ulnar shaft just proximal to the fusion [44]. The procedure is indicated in younger, more active patients with incongruity of the distal radioulnar joint and patients who have ulnocarpal abutment in the presence of incongruity of the distal radioulnar joint. When creating the distal radioulnar fusion, it is essential to create a neutral ulnar variance. It also is important to create the pseudarthrosis as distally as possible to leave a long ulnar stump to minimize the chances of late radioulnar impingement. In the presence of advanced ulnocarpal impaction with arthrosis of the lunotriquetral joint, lunotriquetral arthrodesis must be performed in addition to ulnar recession. A dorsal skin crease incision is centered over the joint and is developed with preservation of the dorsal sensory branch of the ulnar nerve. Exposure of the joint is made by a capsulotomy deep to the ﬁfth extensor compartment. After excising the articular cartilage from the dorsal two thirds of the joint, a guidewire for cannulated screw ﬁxation is passed across the joint through a separate ulnar stab incision. The central placement of the guidewire is conﬁrmed on ﬂuoroscopy. The joint is packed with cancellous graft obtained from the distal radius, and the arthrodesis can be stabilized with Kirschner wires or a headless screw of appropriate length (Fig. 9). After screw ﬁxation, the wrist is protected in a cast until wound healing followed by supervised mobilization in a removable splint until radiographic union.

Fig. 9. Lunotriquetral arthrodesis using a headless compression screw.

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Summary Ulnar impaction is a frequent cause of ulnar-sided wrist pain and eventually leads to lunotriquetral arthritis. The diagnosis can be made clinically and can be conﬁrmed by imaging studies. Arthroscopy allows assessment of pathology and the option to proceed to treatment. Decompression of the ulnocarpal articulation is the mainstay of treatment and can be achieved by recession of the ulnar shaft or excision of a wafer from the distal end of the ulna. Arthrosis of the lunotriquetral joint, if present, must be addressed by arthrodesis at the same time.

References [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] [25] [26] [27] [28] [29] [30] [31] [32] [33]

Milch H. Cuff resection of the ulna for malunited Colles’ fracture. J Bone Joint Surg Am 1941;23:311–3. Bell MJ, Hill RJ, McMurtry RY. Ulnar impingement syndrome. J Bone Joint Surg Br 1985;67:126–9. Lewis O. Evolutionary changes in the primate wrist and inferior radioulnar joints. Anat Rec 1965;151:275–86. Palmer AK, Werner FW. The triangular ﬁbrocartilage complex of the wrist-anatomy and function. J Hand Surg Am 1981;6:153–62. Ambrose L, Posner MA. Lunate-triquetral and midcarpal joint instability. Hand Clin 1992;8:653–68. Hulte´n O. Uber anatomische Variationen der Handgknochen. Acta Radiol 1928;9:155–68. Schuind FL, Linscheid RL, An KN, et al. A normal data base of posteroanterior roentgenographic measurements of the wrist. J Bone Joint Surg Am 1992;74:1418–29. Adams BD, Samani JE, Holley KA. Triangular ﬁbrocartilage injury: a laboratory model. J Hand Surg Am 1996;21: 189–93. Werner FW, Palmer AK, Fortino MD, et al. Force transmission through the distal ulna: effect of ulnar variance, lunate fossa angulation, and radial and palmar tilt of the distal radius. J Hand Surg Am 1992;17:423–8. Jeffries AC, Craigen MA, Stanley JK. Wear patterns of the articular cartilage and triangular ﬁbrocartilaginous complex of the wrist: a cadaveric study. J Hand Surg Br 1994;19:306–9. Palmer AK, Glisson RR, Werner FW. Ulnar variance determination. J Hand Surg Am 1982;7:376–9. Chen NC, Wolfe SW. Ulna shortening osteotomy using a compression device. J Hand Surg Am 2003;28:88–93. Chun S, Palmer AK. The ulnar impaction syndrome: follow-up of ulnar shortening osteotomy. J Hand Surg Am 1993;18:46–53. Feldon P, Terrono AL, Belsky MR. The ‘‘wafer’’ procedure: partial distal ulnar resection. Clin Orthop 1992;275: 124–9. Loh YC, Van Den Abeele K, Stanley JK, et al. The results of ulnar shortening for ulnar impaction syndrome. J Hand Surg Br 1999;24:316–20. Rayhack J, Gasser SI, Latta LL, et al. Precision oblique osteotomy for shortening of the ulna. J Hand Surg Am 1993;18:908–18. Tolat AR, Sanderson PL, De Smet L, et al. The gymnast’s wrist: acquired positive ulnar variance following chronic epiphyseal injury. J Hand Surg Br 1992;17:678–81. Palmer AK. Triangular ﬁbrocartilage complex lesions: a classiﬁcation. J Hand Surg Am 1989;14:594–606. Mikic ZD. Age changes in the triangular ﬁbrocartilage of the wrist joint. J Anat 1978;126:367–84. Garcia-Elias M. Dorsal fractures of the triquetrum-avulsion or compression fractures? J Hand Surg Am 1987;12: 266–8. Nakamura R, Horii E, Imaeda T, et al. The ulnocarpal stress test in the diagnosis of ulnar-sided wrist pain. J Hand Surg Br 1997;22:719–23. Tomaino MM, Rubin DA. The value of the pronated-grip view radiograph in assessing dynamic ulnar positive variance: a case report. Am J Orthop 1999;28:180–1. Osterman AL, Bora FW, Maitin E. Arthroscopic debridement of triangular ﬁbrocartilage complex tears. Arthroscopy 1990;6:120–4. Levinsohn EM, Rosen ID, Palmer AK. Wrist arthrography: value of the three-compartment injection method. Radiology 1991;179:231–9. Zinberg EM, Palmer AK, Coren AB, et al. The triple-injection wrist arthrogram. J Hand Surg Am 1988;13:803–9. Pin PG, Semenkovich JW, Young VL, et al. Role of radionuclide imaging in the evaluation of wrist pain. J Hand Surg Am 1988;13:810–4. Zlatkin MC, Chao PC, Osterman AL, et al. Chronic wrist pain: evaluation with high-resolution MR imaging. Radiology 1989;173:723–9. Escobedo EM, Bergman AG, Hunter JC. MR imaging of ulnar impaction. Skeletal Radiol 1995;24:85–90. Darrow JC Jr, Linscheid RL, Dobyns JH, et al. Distal ulnar recession for disorders of the distal radioulnar joint. J Hand Surg Am 1985;10:482–91. Mizuseki T, Tsuge K, Ikuta Y. Precise ulna-shortening osteotomy with a new device. J Hand Surg Am 2001;26: 931–9. Labosky DW, Waggy CA. Oblique ulnar shortening osteotomy by a single saw cut. J Hand Surg Am 1996;21:48–59. Wehbe MA, Cautilli DA. Ulnar shortening using the AO small distractor. J Hand Surg Am 1995;20:959–64. Kawano M, Nagaoka K, Fujita M, et al. New technique for ulnar shortening osteotomy. Techniques Hand Upper Extremity Surg 1998;2:242–7.

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[34] Chen F, Osterman AL, Mahony K. Smoking and bony union after ulna-shortening osteotomy. Am J Orthop 2001; 30:486–9. [35] Deshmukh SC, Shanahan M, Coulthard D. Distal radioulnar joint incongruity after shortening of the ulna. J Hand Surg Br 2000;25:434–8. [36] Tolat AR, Stanley JK, Trail IA. A cadaveric study of the anatomy and stability of the distal radioulnar joint in the coronal and transverse planes. J Hand Surg Br 1996;21:587–94. [37] Minami A, Kato H. Ulnar shortening for triangular ﬁbrocartilage complex tears associated with ulnar positive variance. J Hand Surg Am 1998;23:904–8. [38] Bilos ZJ, Chamberland D. Distal ulnar head shortening for treatment of triangular ﬁbrocartilage complex tears with ulna positive variance. J Hand Surg Am 1991;16:1115–9. [39] Constantine KJ, Tomaino MM, Herndon JH, et al. Comparison of ulnar shortening osteotomy and the wafer resection procedure as treatment for ulnar impaction syndrome. J Hand Surg Am 2000;25:55–60. [40] Tomaino MM. Results of the wafer procedure for ulnar impaction in the ulnar negative and neutral wrist. J Hand Surg Br 1999;24:671–5. [41] Tomaino MM, Weiser RW. Combined arthroscopic TFCC debridement and wafer resection of the distal ulna in wrists with triangular ﬁbrocartilage complex tears and positive ulnar variance. J Hand Surg Am 2001;26:1047–52. [42] Wnorowski DC, Palmer AK, Werner FW, et al. Anatomic and biomechanical analysis of the arthroscopic wafer procedure. Arthroscopy 1992;8:204–12. [43] Bowers WH. Distal radioulnar joint arthroplasty: the hemiresection-interposition technique. J Hand Surg Am 1985; 10:169–78. [44] Sauve K. Nouvelle technique traitement chirurgical des luxations recidivantes isolees de l’extremite inferieure du cubitus. J Chir 1936;47:589–94.

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Lunotriquetral arthritis: clinical and radiographic assessment Peter J. Evans, MD, PhD, FRCSC Shoulder, Elbow and Hand Surgery, Orthopaedic Surgery and Peripheral Nerve Center, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA

Lunotriquetral (LT) arthritis presents as one of several causes of ulnar-sided wrist pain and can be diﬃcult to diﬀerentiate from these often coexisting entities. Diagnosis requires a careful history and physical examination, radiographic studies, diagnostic injections, and in some cases, arthroscopy is required to conﬁrm the diagnosis and direct subsequent treatment.

History Although coexisting radial or central radiocarpal pathology may be present, patients with LT arthritis typically localize their pain to the ulnar side of the wrist. Pronation and ulnar deviation, especially with axial loading movements, typically cause LT pain, a click, or crepitation. Power gripping is achieved by way of the ulnar digits with the wrist in extension and ulnar deviation, thus increasing the load across the ulnar side of the wrist, resulting in pain with LT arthritis. Ulnar deviation pain also can represent midcarpal instability or a triquetrohamate (TH) ligament tear or arthritis. Ulnar-sided pain with forearm rotation favors more proximal problems in and around the distal radial ulnar joint (DRUJ) such as DRUJ arthritis, DRUJ capsular contracture or instability, triangular ﬁbrocartilage complex (TFCC) tears and extensor carpi ulnaris (ECU) subluxation or tendonitis, and ulnar styloid fractures or nonunions. With wrist ﬂexion, dorsal ulnar pain favors traction pain caused by injured dorsal soft tissues such as the ulnocarpal ligaments, dorsal radioulnar ligament portion of the TFCC, and the ECU. With wrist extension, dorsal ulnar pain could represent any cause of ulnar impaction pain, including DRUJ, ulnar head, lunate and triquetral chondromalacia, TFCC tear, LT or TH ligament tear or arthritis, LT coalition or synostosis, dorsal triquetral avulsion fracture/nonunion, and entrapment of the ulnar cutaneous nerve. Palmar ulnar pain could represent pisotriquetral arthritis or ﬂexor carpi ulnaris (FCU) tendonitis, hook of hamate fracture/nonunion, and ulnar neurovascular pathology.

Physical examination Although history dictates the amount of time spent on the individual components of a wrist examination, the examination itself should be the same systematic routine performed on all patients, thus minimizing the chance of erroneous diagnosis. Examination should include range of motion of the shoulder, elbow, forearm, wrist and hand. Palpation should begin with other areas of the wrist and hand and ﬁnish with the LT and TH joint and the ulnar snuﬀ box over the triquetrum in the area distal to the ulnar styloid E-mail address: [email protected] 1082-3131/04/$ - see front matter Ó 2004 Elsevier Inc. All rights reserved. doi:10.1016/S1082-3131(03)00079-7

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Fig. 1. Ulnocarpal stress test. Ulnar deviation, axial load, and a prono-supination force are applied. The test is positive if this produces ulnar-sided wrist pain. A painless click is nondiagnostic.

between the ECU and FCU [1]. Several manipulative tests have been described, but none have been evaluated scientiﬁcally in predictive value for LT tears, instability, or arthritis. The simplest manipulative test is the ulnocarpal stress test described by Nakamura et al (Fig. 1) [2]. The patient’s hand is grasped and forced into ulnar deviation by one of the examiner’s hands while the examiner’s other hand applies an axial load across the joint by way of pressure applied to the elbow, which is ﬂexed 90 . The forearm then is rotated in supination– pronation. The test is positive if this produces ulnar-sided wrist pain. A painless click is nondiagnostic. Any cause of ulnocarpal impaction may illicit pain with this maneuver. Manipulative tests intent on isolating the LT joint include the LT Ballottement test described by Regan [3], the LT shear test described by Kleinman [4], the LT compression test described by Ambrose and Posner [1], and a set of three tests described by Christodoulou and Bainbridge [5]. The Ballottement test is performed by ﬁrst grasping the lunate between the thumb and index ﬁnger with one hand and then grasping the triquetrum (and pisiform) between the thumb and index ﬁnger of the other hand (Fig. 2). The lunate and triquetrum are displaced in opposite directions (dorsal–palmar) and laxity, pain, or crepitation indicates ligament injury or arthritis. The shear test is performed by ﬁrst stabilizing the lunate with the thumb over the dorsal aspect of the wrist. A force then is applied to the pisiform (and triquetrum) palmarly, resulting in an indirect shear force across the LT joint (Fig. 3). The compression test is performed by applying pressure over the ulnar snuﬀbox, loading the LT and TH joints and causing pain (Fig. 4). The author uses a modiﬁcation of this by starting the wrist in radial deviation, loading the ulnar snuffbox, and then bringing the wrist into ulnar deviation, resisting dorsiﬂexion and palmar translation of the triquetrum, eliciting pain if pathology exists in the LT or TH joints. This is somewhat of an ulnar-sided carpal shift test (Fig. 5). Finally, Christodoulou and Bainbridge described three manipulative tests for LT instability, but in minimal detail. The ﬁrst test (relocation) begins by placing the wrist in full dorsiﬂexion and radial deviation and full forearm pronation. The examiner then pushes their thumb against

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Fig. 2. Ballottement test. Lunate and triquetrum are stressed, and laxity, pain, or crepitation occurs if ligament injury or arthritis exists.

the pisiform palmarly and applies a shear force by way of counter-pressure on the dorsal ulna with the lesser ﬁngers. As the wrist is brought into neutral position, the triquetrum reduces and may click. The second test is performed by placing the wrist in pronation, radial deviation, and neutral ﬂexion. The examiner’s thumb presses down in a palmar direction on the dorsum of the triquetrum while the wrist is brought into ulnar deviation. The third test again starts with the wrist in pronation, radial deviation, and neutral ﬂexion, but the triquetrum is displaced dorsally by the examiner pushing the pisiform (and triquetrum) dorsally with their thumb. Pain on ulnar deviation is reduced, compared with the second test.

Diagnostic injections Probably the best value of anesthetic injections with Xylocaine is in conﬁrming whether or not the ulnar-sided wrist pain is intra-articular (ulnocarpal, LT, or midcarpal) or extra-articular.

Fig. 3. Shear test. Lunate and triquetrum are stressed, resulting in an indirect shear force across the LT joint, and laxity, pain, or crepitation occur if ligament injury or arthritis exists.

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Fig. 4. Compression test. This is performed by applying pressure over the ulnar snuﬀbox, loading the LT and TH joints and causing pain if pathology exists.

Sequential injections into the radiocarpal space (by way of the 3-4 dorsal compartment interval) and the LT (midcarpal joint communicates) should be performed. LT pain relief after radiocarpal injection could occur because of ﬂow into the LT joint through a tear or normal perforations found in more than one third of wrists on cadaveric study [6]. The LT can be difﬁcult to inject in isolation even with ﬂuoroscopy. Manipulative physical examination tests

Fig. 5. Ulnar-sided carpal shift test. The ulnar snuﬀbox is loaded and then the wrist is brought into ulnar deviation, resisting dorsiﬂexion and palmar translation of the triquetrum, eliciting pain if pathology exists in the LT or TH joints.

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Fig. 6. Wrist MRI demonstrating a partial carpal (lunotriquetral) coalition with degeneration (A) and a dorsal ganglion cyst off the LT joint (B).

should then be repeated. Lack of pain relief with anesthetic injection implies a poor chance of success with operative intervention, despite any pathology present.

Imaging studies Radiographs are important and must be taken in a standardized manner. Posteroanterior, lateral, and oblique radiographs should be taken with the forearm in neutral rotation. Subchondral sclerosis, joint space narrowing, and osteophytes often can be seen with arthritis. Ulnar variance can be measured. Radial and ulnar deviation and clenched-ﬁst views may be helpful, because they may demonstrate instability that often leads to arthritis. Disruption in the carpal arcs (Gilula’s lines) [7], widening of the LT interval, volar ﬂexion of the lunate, increase in the capitolunate angle, and decrease in the scapholunate angle (ie, VISI) should be noted. LT instability can be demonstrated further by a triangular shaped lunate (ie, volar ﬂexed) and distal translation of the triquetrum on the hamate (ie, dorsiﬂexed). Work-up of instability can be elucidated further with the use of ﬂuoroscopy documenting any changes in LT distance throughout wrist motion. Ulnar gripping can cause widening of the ulnar midcarpal articulation and palmar subluxation of the capitate on the lunate. Magnetic resonance imaging (MRI) in the wrist has growing applications, but because of the myriad of structures closely packed into a small space, only high resolution MRI with a dedicated wrist coil (which few centers have) can diagnose wrist pathologies. LT carpal synostoses or coalitions can be deﬁned (Fig. 6) and subchondral edema and joint effusion can be seen, but LT tears are difﬁcult to identify. Arthrography has been shown to be unreliable in diagnosing LT tears with high false positive and negative results and oﬀers little in diagnosing arthrosis. Bone scans can be sensitive for inﬂammation and arthrosis, locating these to the ulnar side of the wrist, but diﬀerentiating which articulation is often beyond the resolution of the test.

Arthroscopy Arthroscopy is the most accurate method of diagnosing intra-articular pathology in the wrist, including LT pathology [8]. Arthroscopy more precisely indicates the location, size, and extent of intra-articular ligament and joint injuries often associated with LT pathology, thus facilitating treatment decisions.

Summary LT arthrosis infrequently exists in isolation and represents one of many causes of ulnar-sided wrist pain. Careful history and physical examination, including special manipulative tests, in

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conjunction with radiography and at times arthroscopy can lead to an accurate diagnosis and successful management of LT arthrosis.

References [1] Ambrose L, Posner M. Lunate-triquetral and midcarpal joint instability. Hand Clin 1992;8:653–86. [2] Nakamura R, Horii E, Imaeda T, et al. The ulnocarpal stress test in the diagnosis of ulnar-sided wrist pain. J Hand Surg [Br] 1997;22B(6):719–23. [3] Reagan DS, Linschied RL, Dobyns JH. Lunotriquetral sprains. J Hand Surg [Am] 1984;9:502–14. [4] Kleinman WB. Diagnostic exams for ligamentous injuries. Correspondence Club Newsletter. Am Soc Surg Hand 1985;51. [5] Christodoulou L, Bainbridge LC. Clinical diagnosis of triquetrolunate ligament injuries. J Hand Surg [Br] 1999; 24B(5):598–600. [6] Weiss APC, Sachar K, Glowacki KA. Arthroscopic debridement alone for intercarpal ligament tears. J Hand Surg [Am] 1997;22:344–9. [7] Totty WG, Gilula LA. Imaging of the hand and wrist. In: The traumatized hand and wrist. Radiographic and anatomic correlation. Gilula LA, editor. Philadelphia: WB Saunders Company; 1992. p. 1–18. [8] Weiss LE, Taras JS, Sweet S, et al. Lunotriquetral injuries in the athlete. Hand Clin 2000;16(3):433–8.

Atlas Hand Clin 9 (2004) 105–113

The role of arthroscopy in the management of lunotriquetral arthritis Gary Kuzma, MD Wake Forest University, Bowman Gray School of Medicine, Hand Center of Greensboro, 2718 Henry Street, Greensboro, NC 27405, USA

Arthritis between isolated carpal bones is an uncommon occurrence. Arthritis rarely involves the lunotriquetral joint, and when it does occur, it represents only a small percentage of patients complaining of pain on the ulnar side of the wrist. These patients rarely show a loss of mobility, and physical examination is essentially normal. Pain may be elicited with ballottement of the lunate and triquetrum. Grip strength usually is diminished. Careful examination and a high index of suspicion may lead the clinician to suspect the underlying cause of degeneration of the lunotriquetral joint. Close inspection of radiographs is necessary to discover an incomplete or partial lunate-to-triquetrum carpal coalition resulting in arthritis and causing ulnar wrist pain. Clinicopathogenesis The formation of the carpal bones occurs during the fourth to eighth week of gestation, when cavitation of the common cartilaginous precursor divides into the individual carpal bones. If there is incomplete cavitation when ossiﬁcation of the carpal bones occurs, a congenital carpal coalition becomes progressively more apparent radiographically as maturation progresses [1]. Incomplete separation of the lunate and triquetrum is the most commonly occurring congenital carpal coalition in the wrist [2]. When the coalition is incomplete and no bony bridge is present, the potential for the development of degenerative arthritis at the site of the partial coalition exists. This is a consequence of the relatively thin inadequate layer of cartilage between the lunate and the triquetrum. With time, this thin layer of cartilage gradually wears out, leading to a localized degenerative arthritis. The frequency of lunotriquetral coalition in the general population varies from 1.0% in Europeans to 9.5% in black women [1]. The female-to-male ratio is 2:1, and inheritance seems to be multifactorial [3,4]. A system of classiﬁcation has been proposed by Minnaar [5] based on the anatomic variation of the coalition. He proposed four types of coalitions, as follows: Type Type Type Type

I—incomplete fusion resembling a pseudarthrosis (ﬁbrocartilaginous coalition) (Fig. 1) II—incomplete osseous fusion (Fig. 2) III—incomplete osseous fusion (os lunotriquetrum) (Fig. 3) IV—complete osseous fusion associated with other carpal anomalies

The next most common congenital coalition of the carpus involves the capitate hamate articulation. These coalitions are rare and usually are found on incidental radiographic evaluation after minor trauma. They generally are asymptomatic and may be present with type IV lunotriquetral coalition. Generally the osseous coalition of the lunate and triquetrum remains asymptomatic and results in no loss of wrist mobility [5,6]. Fractures of these coalitions have been reported as a rare cause of ulnar wrist pain [1,7,8]. Some of these fractures may have been through E-mail address: [email protected] 1082-3131/04/$ - see front matter Ó 2004 Elsevier Inc. All rights reserved. doi:10.1016/S1082-3131(03)00073-6

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Fig. 1. (A) Minnaar type I lunotriquetral coalition. Radiograph shows incomplete fusion resembling a pseudarthrosis with ﬁbrocartilaginous coalition of the lunotriquetral joint. (B) Drawing of Minnaar type I coalition.

ﬁbrocartilaginous coalitions [9,10]. Although some investigators believe that all lunotriquetral coalitions remain asymptomatic [5,6], others authors believe that Minnaar type I coalitions should be differentiated from osseous coalitions [2]. When there is no osseous connection, the ﬁbrocartilaginous coalition lacks a sufﬁcient ligamentous and bony construct for stabilization and represents pseudarthrosis that is likely to become symptomatic [11]. Minnaar type I coalition poorly tolerates stress loading or trauma and can result in wrist pain after seemingly minor trauma [2,11]. Support of this theory is seen in reports of patients who have symptomatic Minnaar type I and asymptomatic Minnaar type III coalitions in opposite wrists [12]. The role of trauma with fracture through the partial coalition compared with the role of cartilage degeneration and arthritis producing symptoms in Minnaar type I coalition still is debated. Each mechanism has been proposed, and each has it proponents. Heavy stress and use can cause wear and premature degeneration of the inadequate cartilage or cartilaginous bridge, resulting in symptoms [2]. Ritt et al [4] found that 10 of 12 patients became symptomatic between the ages of 25 and 40 years. Fractures through an incomplete coalition with inadequate bone or cartilage from a traumatic episode also may render the patient symptomatic [11]. This mechanism has support in Ritt’s series, with three patients reporting an injury preceding the onset of symptoms. It is possible that there are two subgroups of the type I coalition: (1) an incomplete ﬁbrocartilaginous coalition, which can be injured, fractured, and result in symptoms, and (2) a coalition that is essentially complete but with a thin articular cartilaginous surface proximally, which is inadequate and undergoes early degenerative degradation. Diagnosis The diagnosis of lunotriquetral coalition rests on radiographic analysis. Radiographs of the lunotriquetral joint with Minnaar type I coalition are reported to have a pathognomonic

Fig. 2. (A) Minnaar type II lunotriquetral fusion. Radiograph shows incomplete osseous fusion. Note cleft in the interval between lunotriquetral joint but bone trabeculae crossing fusion site. (B) Drawing of Minnaar type II coalition.

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Fig. 3. (A) Minnaar type III. Radiograph shows incomplete osseous fusion or an os lunotriquetrum with complete fusion of the lunate to triquetrum. (B) Drawing of Minnaar type III coalition.

appearance with a ‘‘ﬂuted champagne glass’’ conﬁguration as described by Watson and Weinzweic (Fig. 4) [13]. In addition, cyst formation and sclerosis similar to pseudarthrosis may be present radiographically [14]. Resnick et al [9] believed that the presence of subarticular, rounded radiolucencies resulted from remnants of displaced synovial tissue in the bones and indicated the disorganized joint developmental process. MRI may be useful especially when combined with gadolinium-DTPA enhancement [12,14]. Not only can the ﬁbrous coalition be visualized better using MRI (Fig. 5), but also bone marrow edema and enhancement of synovium and subarticular cyst can help explain the presence of ulnar wrist pain (Figs. 5 and 6) [14]. Nuclear medicine scan may show increased uptake indicating arthritic degeneration (Fig. 6). The role of arthroscopy in the treatment of arthritis of the lunotriquetral joint secondary to ﬁbrocartilaginous coalition is not well deﬁned. Arthroscopic de´bridement of the degenerative joint would be technically feasible. Open de´bridement of a post-traumatic disruption of Minnaar type I coalition has not been successful, however. Van Schoonhoven et al [12] described one patient who did not have symptoms resolve after simple de´bridement. The patient ultimately required an open fusion of the lunate to triquetrum (Fig. 7; see Fig. 6). The diagnosis of fracture or instability of the ﬁbrocartilaginous coalition versus arthritis of the lunotriquetral joint potentially may be visible or able to be diagnosed using arthroscopy. In addition, the author has seen several cases of volar intercalated segment instability associated with lunotriquetral coalition. The author did not have the opportunity to perform arthroscopy on a patient who was symptomatic with midcarpal instability, however. In each of the patients seen by the author, the opposite asymptomatic wrist showed similar deformities. Arthroscopy may be useful in visualizing and deﬁning injury to the intercarpal or extrinsic ligaments of the wrist, which result in generation of this instability pattern.

Fig. 4. Radiograph shows a pathognomonic ﬁnding for a Minnaar type I lunotriquetral coalition as described by Watson. (A) Incomplete coalition. (B) The champagne glass outlined in black.

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Fig. 5. MRI of a Minnaar type I coalition. Note the changes of sclerosis and edema present.

Treatment The treatment of symptomatic partial lunotriquetral coalition has been isolated fusion of the lunate to the triquetrum. Lunotriquetral fusion has had a favorable and predictable outcome with acceptable wrist motion in almost all cases [2,4,11,12]. Consequently, lunotriquetral fusion is the treatment of choice for this condition. Arthroscopic fusion of the ﬁbrocartilaginous coalition is conceivably possible with percutaneous or mini open placement of a headless screw. Partial wrist fusions have been performed arthroscopically. The author’s experience with these procedures has been limited primarily by the ability to place adequate graft, either as autogenous graft or as synthetic graft, to result consistently and predictably in fusion. Ritt et al [4] believed that the use of cancellous bone graft is not necessary in the treatment of symptomatic lunotriquetral coalition with resulting degenerative arthritis. These investigators found that union of the lunate and triquetrum was achieved in ﬁve of ﬁve attempted cases by

Fig. 6. Bone scan with degenerative changes. Notice the increased uptake in the lunotriquetral joint.

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Fig. 7. Arthroscopic view of lunotriquetral joint from the midcarpal portal with a Minnaar type I coalition with a probe in the lunotriquetral joint.

simply removing the remaining cartilage and compressing the two bones with a headless screw (Figs. 8–14). This approach would allow arthroscopic techniques with percutaneous ﬁxation to become a viable alternative. The unique dynamics of the lunotriquetral joint and advances in ﬁxation using headless screws make this a potential technique especially in the small group of patients with this condition. Isolated lunotriquetral fusions have had variable success in traumatic injuries of the wrist not associated with lunotriquetral coalition [15]. In a wrist with a Minnaar type I coalition, however, lunotriquetral fusion restores the normal anatomy and mechanics for the wrist and should result in greater success (Fig. 15). In unusual situations, ulnar four-bone fusion or proximal row carpectomy has been advocated [4,15]. In Ritt et al’s [4] report of nine patients with 12 symptomatic wrists with Minnaar type I coalition, proximal row carpectomy was performed in 3 cases, and lunotriquetral fusion was performed in 5 cases. The choice of procedure may be best dictated by

Fig. 8. Preoperative radiograph of a 30-year-old patient with symptomatic Minnaar type I lunotriquetral coalition.

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Fig. 9. Radiograph of patient in Fig. 8 shows the placement of a headless screw for lunotriquetral fusion.

the presence or absence of midcarpal instability. Isolated fusion of the lunate to triquetrum in the presence of midcarpal instability would fail, and ulnar four-bone fusion or proximal row carpectomy becomes the treatment of choice when coalition and midcarpal instability are present. Arthroscopy also may prove to be beneﬁcial in midcarpal instability with the possibility of tightening of the midcarpal ulna and ulnar lunate and ulnar triquetral ligaments by thermal shrinkage. Thermal shrinkage has been shown to be eﬀective in tightening partial tears of the scapholunate ligaments (Geissler WB. Presentation at American Association of Hand Surgeons Annual Meeting. Kauai, Hawaii, 2003). The author has had limited experience in this procedure but has met with some success in traumatic cases. Shrinkage of the ulnar-sided ligaments may provide stabilization for midcarpal instability when noted with carpal coalition. The author performed one case of arthroscopic thermal shrinkage of the ulnar ligaments of the proximal

Fig. 10. Postoperative radiograph of patient in Fig. 8 shows lunotriquetral fusion.

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Fig. 11. Arthroscopic view of a patient undergoing four-bone fusion from midcarpal joint. A bur is removing subchondral bone of lunate and triquetrum.

and midcarpal joints in a patient with lunotriquetral coalition and midcarpal instability. The deformity occurred after a fall and was not present on the opposite wrist. During arthroscopic inspection of the wrist, the volar ulnolunate and ulnotriquetral were found to be partially torn and involuted into the joint, whereas the midcarpal component of the arcuate ligament was stretched. Improvement of the capitate-lunate angle and diminution of the volar ﬂexed position of the capitate and lunate were achieved after de´bridement and shrinkage. The patient’s preoperative pain has been eliminated. Follow-up time is short, however, and long-term follow-up is necessary to determine the efﬁcacy of arthroscopic treatment of this signiﬁcant deformity. The technique of thermal shrinkage of the ulnar ligaments is described elsewhere in this issue. Arthroscopy in the treatment of arthritis of the lunotriquetral joint remains in its infancy due to the infrequency of presentation of the underlying process. Fusion of the lunate to the triquetrum using a headless cannulated, percutaneously placed screw without the use of graft

Fig. 12. Placement of pin across lunotriquetral joint viewed arthroscopically from midcarpal portal.

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Fig. 13. Arthroscopic view of pin placement for arthroscopic ulnar four-bone fusion.

can be performed using standard wrist arthroscopy techniques. Wrist arthroscopy has been employed to perform ulnar four-bone fusion and proximal row carpectomy (Culp RW. Personal communication, 2003). Capsular shrinkage and arthroscopic fusion of the lunate to triquetrum with percutaneous ﬁxation may prove to be viable options in treatment of patients with coalition and midcarpal instability. Sparing the dorsal ligaments and decreased scarring associated with use of arthroscopy may result in improved function and patient satisfaction in the treatment of symptomatic Minnaar type I lunotriquetral coalition resulting in lunotriquetral arthritis. The role of wrist arthroscopy in the treatment of this rare condition has not been deﬁned, but it has the potential to play an increased role.

Fig. 14. Radiograph shows postoperative placement of headless screws for ulnar four-bone fusion.

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Fig. 15. Radiograph of patient with lunotriquetral coalition and midcarpal instability.

References [1] Cockshutt WP. Carpal fusion. AJR Am J Roentgenol 1963;89:1260–2. [2] Gross SC, Watson HK, Strickland JW, et al. Triquetral-lunate arthritis secondary to synostosis. J Hand Surg Am 1989;14:95–102. [3] Garn SM, Frisancho AR, Poznanski AK, et al. Analysis of triquetral-lunate fusion. J Phys Anthropol 1971;34A: 431–4. [4] Ritt MS, Maas M, Bos KF. Minnaar type I, symptomatic lunatotriqeutral coalition: a report of nine patients. J Hand Surg Am 2001;26:261–70. [5] Minnaar AB deV. Congenital fusion of the lunate and triquetral bones in the South African Bantu. J Bone Joint Surg 1952;343:45–58. [6] Delane JS, Eswar S. Carpal coalitions. J Hand Surg Am 1992;17:28–31. [7] Hocker K, Renner J. Fraktur eines us Lunatotriquetrum im triquetralen Antiel. Falldarstellung and Literaturibusicht Handchir M. Krochir Plast Chir 1995;27:254–7. [8] Rohde H. Fraktur und Pseudarthrosis einer lunatum-triquetrum-synostose und ihre Behaudlung. Arch Orthop Trauma Surg 1978;91:97–9. [9] Resnick CS, Grizzard JD, Simmons BP, et al. Incomplete carpal coalition. AJR Am J Roentgenol 1986;147:301–4. [10] Zielinski CS, Gunther SE. Congenital fusion of the scaphoid and trapezium: case report. J Hand Surg 1981;6:220–2. [11] Simmons BP, McKenzie WD. Symptomatic carpal coalition. J Hand Surg Am 1985;10:190–3. [12] Van Schoonhoven J, Prommensberger KS, Schmitt R. Traumatic description of a ﬁbrocartilage lunate-triquetral coalition: a case report and review of the literature. Hand Surg 2001;6:103–8. [13] Watson HK, Weinzweic J. The wrist. Philadelphia: Lippincott Williams & Wilkins; 2001. p. 533–4. [14] Stabler A, Glaser C, Reiser M, et al. Symptomatic ﬁbrous lunato-triquetral coalition. Eur Radiol 1999;9:1643–6. [15] Vandesade W, DeSmet L, Van Ransbeech H. Lunatotriquetral arthrosis, a procedure with a high failure rate. Acta Orthop Belg 2001;67:361–7.

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Lunotriquetral arthrodesis Vincent Novak, MD, Ethan R. Wiesler, MD* Department of Orthopaedic Surgery, Wake Forest University Baptist Medical Center, Medical Center Boulevard, Winston-Salem, NC 27157, USA

Lunotriquetral joint pathology is a recognized cause of ulnar-sided wrist pain. The diagnosis and treatment of such injuries, however, remain challenging and controversial. Arthrodesis of the lunotriquetral joint is one method that has been used with variable results reported in the literature. This article provides a concise review of the indications, methods, and results of lunotriquetral arthrodesis (LTA) based on a comprehensive review of current literature. This is preceded by a discussion of relevant carpal anatomy, mechanics, stability, pathomechanics, and diagnosis of lunotriquetral (LT) pathology.

Anatomy, physiology, and mechanics A ﬁrm foundation and understanding of wrist anatomy, function, and stability is essential and should precede discussion of speciﬁc injuries, their diagnosis, and potential treatment options. Although numerous investigations of carpal anatomy and kinematics have helped further our understanding, much work remains toward better elucidating these complex interactions [1–13]. Ligamentous anatomy Several anatomic investigations have detailed the anatomy and function of wrist ligaments [2,14–16]. The major ligaments and their associated function are summarized in Table 1. Multiple classiﬁcation schemes exist, including dorsal capsular, volar capsular, and interosseous categories. There are unique features within each group. The dorsal capsular ligaments indirectly stabilize the scaphoid and function as a collective dorsal radioscaphoid ligament. The volar capsular ligaments are intra-articular and therefore often best visualized arthroscopically. Current theory supports the concept that palmar extrinsic ligaments provide more wrist stability than dorsal extrinsic ligaments [10]. The oblique orientation of volar and dorsal radiocarpal extrinsic ligaments resists the tendency of the axially loaded carpus to slide down the inclined radius in an ulnar and volar direction [10]. Carpal kinematics and stability Wrist kinematics are largely a response to indirect forces across the carpus guided by a complex arrangement of ligamentous and capsular constraints. With the exception of the ﬂexor carpi ulnaris, there are no wrist motors that insert directly into the carpal bones. Wrist stability can be deﬁned as the ability to maintain normal carpal relationships under physiologic loads throughout a full arc of joint motion [3]. In contrast, wrist instability represents the inability to maintain these normal spatial relationships under physiologic loads, statically or dynamically.

* Corresponding author. E-mail address: [email protected] (E.R. Wiesler). 1082-3131/04/$ - see front matter Ó 2004 Elsevier Inc. All rights reserved. doi:10.1016/j.ahc.2003.12.001

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Table 1 Regional and functional classiﬁcation of wrist ligaments Group Intercarpal Proximal interosseous Distal interosseous

Palmar midcarpal

Speciﬁc ligaments Scapholunate Lunotriquetral Trapeziotrapezoid (dorsal and palmar) Trapeziocapitate (dorsal and palmar) Capitohamate (dorsal and deep) Scaphocapitate Triquetrocapitate Triquetrohamate

Function Connect individual carpal bones Strongest ﬁbers: volar LT, dorsal SL

Form deltoid or arcuate ligament

Scaphotrapeziotrapezoid Dorsal

Dorsal intercarpal ligament

Indirectly stabilizes scaphoid to radius by way of dorsal RC ligament. Provides transverse stability to proximal carpal row

Origin: triquetrum Insertion: scaphoid, trapezoid Radiocarpal Palmar

Radioscaphocapitate ! Radiolunate (short and long) Radioscapholunate

Dorsal

Ulnocarpal

Distal radioulnar

Dorsal radiocarpal Origin: dorsal rim radius Insertion: dorsal cortices of lunate and triquetrum Ulnocapitate Ulnolunate Ulnotriquetral

Scaphoid ‘‘seatbelt’’ Prevent volar/ulnar migration of carpus down radial inclination Vestigial vascular conduit. No functional signiﬁcance Stabilize proximal carpal row to radius

Resist supination of hand relative to forearm

Radioulnar (dorsal and palmar) Triangular articular disc Joint capsule

Carpal kinematics associated with physiologic wrist motion have been described in the literature. Typical wrist arcs of motion include 150 ﬂexion–extension and 50 radioulnar deviation. Most ﬂexion and radioulnar deviation (60%) occur at the midcarpal articulation, whereas the extension occurs predominantly (66%) at the radiocarpal articulation [3]. Radial and ulnar deviation shifts the position of the entire proximal carpal row to one of ﬂexion and extension, respectively. Ruby et al used cadaveric specimens to study the kinematics of intercarpal motion during physiologic wrist motion and found that signiﬁcantly more motion occurs between carpal rows than between individual carpal bones. Similar to the scapholunate articulation, the LT articulation demonstrated approximately twice the motion of other intercarpal segments. Motion at the LT joint was found to be primarily rotational motion (versus translational) with minimal displacement [9]. Others consider the lunate and triquetrum to move synchronously, with little motion within each row of the ulnar carpus, and hence would anticipate little functional loss following limited fusion of these two carpal bones [1,17]. This latter concept supports the observation that congenital LT coalition causes little loss of wrist motion. Lunotriquetral ligament The lunotriquetral (LT) ligament is the major intrinsic stabilizing structure of the LT articulation and a key stabilizer of the wrist joint [8]. Similar to the scapholunate ligament, the C-shaped LT ligament may be divided into dorsal, proximal, and volar regions based on histologic variations. The volar portion is the thickest and strongest, and thus plays a critical role in providing stability to the articulation. The dorsal portion is thinner than its volar counterpart, but has been shown to provide the greatest rotational stability to the LT joint [18]. The proximal or central portion is the thinnest and provides essentially no additional stability

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[3]. The unique ﬁbrocartilage composition of this proximal portion predisposes the LT ligament to age-related degeneration and may lead to ulnar-sided wrist pain without instability [19]. Additional extrinsic support to the lunotriquetral articulation also is provided by the dorsal radiocarpal ligaments that stabilize the proximal carpal row to the radius [3]. Pin et al evaluated the mechanical properties of intrinsic (scapholunate and lunotriquetral) and extrinsic (dorsal radiocarpal) ligaments, and found that the LT ligament demonstrated the highest stiffness and ultimate failure load [20]. Their results provide a biomechanic basis to explain why intrinsic ligaments may rupture ﬁrst and leave attenuated extrinsic ligaments intact. Lunotriquetral coalition Although coalition has been described between all adjacent carpal bones, lunotriquetral coalition remains the most common [2,21]. Reported incidence varies from 0.1% in Caucasians to as high as 62% bilaterally in certain Nigerian populations [22,23]. Classiﬁcation of lunotriquetral carpal coalition into four types was ﬁrst described by DeVilliers Minaar in 1952 [24]. Coalition types 1–4 correspond to (1) partial pseudarthrosis, (2) incomplete, (3) complete, and (4) complete plus other carpal anomalies. The observation that patients with congenital LT fusion are often asymptomatic with normal wrist motion has fueled the concept of LTA [25,26]. Patients with symptomatic, incomplete fusions have been reported in the literature, however, and LTA may be the surgical treatment of choice for such patients [21,27,28].

Mechanisms of injury and pathomechanics Wrist instability Instability patterns represent a spectrum of severity. For example, a partial attritional tear of the LT ligament may behave much diﬀerently than a complete ligament tear with associated perilunate dislocation. In an eﬀort to better understand wrist kinematics and instability, multiple theories have been proposed based on previous cadaveric studies. These include the row theory, column theory, and oval-ring theory [6,9]. Mayﬁeld et al also have described a spectrum of progressive perilunate instability, ranging from isolated scapholunate ligament injury to frank perilunate dislocation [15]. Larsen et al provided a descriptive classiﬁcation of wrist instability that includes chronicity, constancy (static versus dynamic), etiology, location (radiocarpal versus midcarpal), direction (DISI versus VISI), and pattern (dissociative versus nondissociative) [5]. Lunotriquetral instability LT dissociation represents the second most common ligamentous cause of carpal instability (after scapholunate instability) and encompasses a continuum of injuries [10]. Complete LT ligament tears associated with perilunate dislocation often follow wrist extension-ulnar deviation injuries and may result in concomitant injury to the scaphoid or scapholunate ligament [29]. In contrast, isolated LT ligament tears may be associated with reverse perilunate dislocation following wrist extension-radial deviation injuries without scapholunate disruption [7]. Acute injury is commonly is associated with a twisting or hyperextension mechanism often combined with forced pronation of the wrist [1,7,30]. Chronic ulnar-sided wrist pain in the absence of trauma may represent attritional rupture of the LT ligament secondary to ulnar impaction syndrome. Surgical intervention may be warranted to avoid progressive carpal collapse and early degenerative joint disease resulting from untreated instability. Under physiologic axial loads, the palmar ﬂexion inﬂuence of the scaphoid and the dorsiﬂexion inﬂuence of the triquetrum on the lunate equilibrate to result in a stable carpal conﬁguration. When the lunotriquetral linkage is lost, the unopposed palmarﬂexion inﬂuence of the scaphoid prevails, resulting in the characteristic volar intercalated segment instability (VISI) pattern. Viegas et al described three stages of perilunate instability with progressive disruption of the proximal LT interosseous ligament, volar LT interosseous ligament, and the dorsal

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radiocarpal ligament [11]. These correlated with insigniﬁcant, dynamic, and static instability, respectively. According to a cadaveric study by Horii et al, the ‘‘essential lesion’’ required to produce a static VISI deformity includes division of the dorsal radiocarpal ligaments in addition to the LT ligament [4]. This suggests that attempted surgical repair of the LT ligament should also address potential injury to the dorsal radiocarpal ligament.

Diagnosis of lunotriquetral pathology History and physical examination Evaluation of a patient with suspected lunotriquetral pathology should begin with a detailed history and physical examination, followed by plain radiographic imaging. History should ascertain onset and duration of symptoms, previous trauma, exacerbating or repetitive activities, occupation, functional demands, hand dominance, and comorbidities. Axial compressionhyperextension type injuries, for example a fall onto the outstretched hand, are common [1,3,7,25]. Patients typically complain of intermittent ulnar-sided wrist pain or aching exacerbated with activity, but symptoms vary with the speciﬁc pathology. Symptoms of patients with carpal instability, for example, might include pain, weakness, subjective instability or giving way, stiffness, ulnar nerve paresthesias, and activity-induced clicks or clunks, especially with radioulnar deviation [7,29]. Physical examination ﬁndings should be compared with the contralateral, uninjured wrist whenever possible. Focal tenderness over the LT interval is nearly universal [7]. Provocative maneuvers (eg, ballottement test, ulnar snuff box test) are suggestive but not diagnostic of LT pathology [25,30]. The ballottement test assesses for LT instability and is positive (abnormal) when laxity, crepitus, and pain are elicited by the examiner with attempted translation of the triquetrum with respect to the remaining stabilized carpus [7]. Note that pisotriquetral pathology also can elicit pain with this test. The ulnar snuff box test is a similar maneuver performed by applying pressure on the ulnar aspect of the triquetrum [1]. Diagnosis may be further complicated, because as many as 70% of triangular ﬁbrocartilage complex tears (TFCC) tears have associated LT ligament tears [10]. Compared with the uninjured extremity, grip strength may be diminished, motion may be decreased, and resisted pronation and supination may elicit pain [25]. Imaging Initial imaging begins with plain radiographs. Standard series should include PA and lateral views of the wrist in neutral forearm rotation. Additional radial and ulnar deviation views may be useful. Although plain radiographs are often normal in patients with underlying LT tears, radiographic ﬁndings suggestive of injury include positive ulnar variance, LT step-oﬀ or widening suggestive of LT dissociation, a volar triquetral avulsion ﬂeck, or VISI deformity on the lateral radiograph [3,7,11,25,29,31]. The lunotriquetral angle assessed on a lateral view of the wrist may be normal (average, 14 ) or abnormal (<0 ) and suggest LT dissociation [7]. One also should look for evidence of degenerative joint disease. Gross et al suggested the association of arthritis secondary to congenital carpal coalition [27]. If static plain ﬁlms are nondiagnostic, stress radiographs may be useful to assess for dynamic LT instability or ulnar impaction syndrome. The AP pronated clenched-ﬁst view is a useful stress radiograph that may elicit radiographic evidence of dynamic instability and can increase ulnar variance by up to 2 mm. Wrist arthroscopy has revolutionized the management of wrist injuries and currently is considered the most deﬁnitive diagnostic tool for evaluating ligamentous pathology of the LT joint, particularly when assessing for carpal instability and clinically suspected ligament tears [13,32,33]. The role of arthroscopy is discussed in detail later (see Treatment Options). Other available imaging modalities include arthrography, tomograms, scintigraphy, videoﬂuoroscopy, CT scans, and MRI [7,29]. Conventional arthrography may be used to conﬁrm clinical suspicion of an LT tear, but ﬁndings must be interpreted cautiously and correlated with physical examination [29]. False negatives may occur and may increase with poor technique, and

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false positives may represent clinically insigniﬁcant ﬁndings [7,13,32]. For example, a positive arthrogram may result from a clinically stable, isolated injury to the proximal portion of the LT ligament that allows contrast passage between the radiocarpal and midcarpal joints through the LT articulation. This has been referred to previously as ‘‘occult instability’’ [34]. Using arthroscopy as a reference standard, wrist arthrography has a 74% sensitivity, 56% speciﬁcity, and 21% negative predictive value [35]. Because routine wrist radiographs often inadequately proﬁle the LT joint, particularly when assessing for postoperative LT fusion, tomograms occasionally may be helpful [30,36]. CT scans should not be considered routine, but may be useful when assessing for congenital carpal coalition or postoperative intercarpal fusion [34]. Bone scans are typically nonspeciﬁc and of little diagnostic value [25,32]. MRI is currently of limited value in diagnosing lunotriquetral ligament tears and should not be the primary method of evaluating for potential carpal instability [1,3,13,29]. Occasionally MRI may help rule out other local pathology, such as Kienbo¨ck’s disease or an occult fracture [1]. MR arthrograms using newer, high-magnet coils (>3 Tesla) with narrow slice imaging techniques are under development and may show promise. Differential diagnosis The diﬀerential diagnosis of LT pathology encompasses all causes of ulnar-sided wrist pain. These include fractures, LT ligament tears (partial versus complete, attritional versus traumatic), distal radioulnar joint (DRUJ) disease, TFCC tears, ulnar styloid pathology, extensor/ﬂexor carpi ulnaris (ECU/FCU) tendonitis, periarticular calciﬁcation, ECU subluxation, degenerative arthritis, triquetrohamate instability, triquetral impingement ligament tear (TILT) syndrome, ulnar impingement syndrome, congenital carpal coalition, and ulnar neurovascular syndromes [7,29,37].

Treatment options Nonoperative Six weeks of cast immobilization may be successful for isolated acute LT tears (<3 months) in the absence of instability [3,7,30]. Unfortunately there is often a signiﬁcant delay between the onset of symptoms and initial presentation. Consequently many patients present with chronic injuries that carry associated diagnostic, therapeutic, and prognostic implications. Other forms of nonoperative treatment that may provide temporary pain relief include nonsteroidal antiinﬂammatory medications, taping for athletes, steroid injections to help decrease synovitis, and phonophoresis [13,29,30]. Operative techniques Management of static and chronic wrist instability remains challenging. Speciﬁc surgical techniques may include arthroscopy and debridement, open reduction with internal ﬁxation, ligamentous repair or reconstruction, limited intercarpal arthrodesis (eg, LTA), ulnar shortening osteotomy, and salvage procedures such as proximal row carpectomy (PRC) or total wrist fusion. In addition to LTA, other limited midcarpal fusions that have been suggested include capitatehamate-lunate-triquetrum (ie, four-corner fusion), and lunate-triquetrum-hamate arthrodeses [17]. Arthroscopy and debridement may be a promising option for painful occult instability as previously deﬁned and has been recommended as the initial treatment of choice for athletes with refractory LT injuries [1,13,34]. Many studies have used arthroscopy to conﬁrm clinically suspected LT injuries [13,32,33,36,31]. Open reduction and intercarpal pinning may be indicated for symptomatic LT instability with or without local degenerative arthritis [1,38]. Direct repair of the LT ligament may be effective in acute or subacute injuries, but may not be indicated in patients with chronic injuries or poor tissue quality [13,29]. LT ligament reconstruction with dorsal capsulodesis has been described for acute and chronic instability situations [7,13]. Ulnar

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shortening osteotomy may be indicated for ulnar impaction syndrome with ulnocarpal abutment in patients with ulnar positive variance. PRC has been used previously as a salvage procedure for LT coalition with associated degenerative changes [21]. Four-corner fusion may be indicated when associated midcarpal degenerative joint disease is present [39]. Limited intercarpal arthrodesis is certainly another surgical option for symptomatic LT pathology, and is described in detail in the following sections. Use of arthroscopy As mentioned earlier, arthroscopy is an accurate method of diagnosing and potentially treating intra-articular ligament injuries [33,36]. It has been shown superior to conventional arthrography and often is considered the gold standard for evaluating wrist instability [3,35]. Arthroscopic evaluation allows for precise localization of injuries, direct visualization of associated pathology (eg, arthrosis, TFCC tears), and conﬁrmation of anatomic positioning during arthrodesis [13]. In addition, concomitant arthroscopic treatment options may include repair of associated injuries (eg, TFCC tears), radial styloidectomy, capsular shrinkage, and debridement of symptomatic partial ligament tears, chondromalacia, or synovitis [33]. Some studies indicate that isolated LT ligament injuries without instability may respond well to arthroscopic debridement alone [33]. Surgical (LTA) techniques Numerous LTA techniques have been reported in the literature. Such methods have included ﬁxation with K-wires, cancellous screws, Herbert screws, staples, and various combinations of these techniques [21,25,26,30–32,38,39]. Bone grafting often has been added in an effort to promote union and maintain normal intercarpal relationships. Autogenous cancellous bone graft obtained from the iliac crest or ipsilateral distal radius has been used most extensively. Shaping of interposition bone grafts in the form of block, winged, or slot grafts, and dowel bone grafting using interference ﬁt with temporary K-wire ﬁxation also has been reported [31,36]. Speciﬁc details of these various surgical methods are mentioned later. Postoperative care Protocols for postoperative care following LTA vary considerably. There is general agreement, however, that immobilization should be continued until there is radiographic evidence of fusion. This has resulted in considerable variation in duration of postoperative immobilization, from 5–14 weeks. Although some studies have demonstrated a signiﬁcant eﬀect of postoperative immobilization on fusion rates, others have not [30,39].

Case example1 A 40-year-old woman sustained an injury to her LT region and presented with complaints of ulnar-sided wrist pain for 6 months. Initial radiographs of the wrist were unremarkable. Arthroscopic examination demonstrated injury to her LT interval, with signiﬁcant attenuation of her volar ligament and complete disruption of the dorsal ligament. At surgical exploration of her wrist, arthritic changes were noted at the LT interval with no appreciable remaining dorsal LT ligament. Because of the associated LT arthrosis, it was believed the patient would be best served by LTA. Surgical technique used a single compression screw (Leibinger Twinﬁx, Kalamazoo, MI) and autogenous distal radius interposition bone graft as illustrated in Figs. 1 and 2. Postoperative AP radiograph following LTA is shown in Fig. 3. Short arm cast

1

Courtesy of A.Y. Shin, MD, and A.T. Bishop, MD, Mayo Clinic, Rochester, MN.

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Fig. 1. Intraoperative illustration of LTA with interposition bone graft placement. (From Shin AY, Weinstein LP, Berger RA, et al. Treatment of isolated injuries of the lunotriquetal ligament: a comparison of arthrodesis, ligament reconstruction and ligament repair. J Bone Joint Surg 2001:83B(7);1023–8; with permission.)

immobilization was continued for 3 months, at which time radiographic evidence of solid fusion was noted. She returned to her previous work at 6 months postoperatively. Reagan et al were the ﬁrst to provide a review of LT sprains and results of surgical treatment, including limited intercarpal arthrodesis [7]. LTA was performed in 7 of 22 patients surgically treated for chronic LT sprains (n = 13) and LT dissociation (n = 9). Average age was 34 years, 69% were male, and 94% reported a history of trauma. Mean follow-up was 42 months. Surgical technique involved open reduction and K-wire ﬁxation. Bone graft was impacted into a trough cut transversely between the two bones, but articular surfaces were not decorticated. Results following LTA in those with chronic tears (n = 4) demonstrated fair-poor results in all patients. LT joint pain resolved in 75% of these patients, however, and persistent symptoms were believed to be more related to associated injuries than to the initial LT injury. In contrast, results following LTA in those with LT dissociation (n = 3) demonstrated good results and complete pain relief in two patients. The third patient required a wrist arthrodesis because of persistent pain. The investigators concluded that results of LTA for chronic LT sprains are variable and partially depend on severity and chronicity of the injury. A review of the literature on various intercarpal arthrodeses by Siegel and Ruby on 143 LTA reported from 1988–1993 reported overall rates of nonunion (26%), complication rate (43%), and persistent postoperative pain (46%) [40]. Primary indications were LT ligament tears and post-traumatic instability. Average follow-up period was limited to 17 months. Their analysis showed that limited arthrodeses that do not cross the midcarpal joint have the greatest motion.

Fig. 2. Schematic of interposition bone graft secured with intraosseous screw ﬁxation. (From Shin AY, Weinstein LP, Berger RA, et al. Treatment of isolated injuries of the lunotriquetal ligament: a comparison of arthrodesis, ligament reconstruction and ligament repair. J Bone Joint Surg 2001:83B(7);1023–8; with permission.)

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Fig. 3. Postoperative AP radiograph of wrist following LTA.

In contrast, those fusions that cross the midcarpal row limit range of motion by approximately 50%. Larsen et al performed a meta-analysis of LTA nonunion rates based on 104 patients in eight independent studies and reported an overall nonunion rate of 27% (95% CI, 19%–36%) [41]. The signiﬁcant variability observed is likely because of the small number of patients within each study, variation in surgical techniques, and difﬁculty in accurately deﬁning and identifying nonunion. Pro lunotriquetral arthrodesis Multiple studies advocate LTA as a viable option for complete LT ligament rupture without static instability, symptomatic LT ligament tears, symptomatic LT instability, degenerative arthritis, and LT coalition [12,21,25,27,28,30,32,36,38]. Pin et al reviewed 11 patients who underwent LTA for chronic complete LT ligament rupture without static instability and found satisfactory results with no observed nonunions [20]. Fusion was achieved in all patients at a mean of 3 months, and 73% of patients returned to their preoperative vocation at 4 months on average. Pain was eliminated or experienced only at extremes of motion in 73% of patients. Diagnosis was conﬁrmed by wrist arthrography in all cases, and associated TFCC tears were noted in 27% of patients. All patients previously failed conservative treatment, including 6 weeks of cast immobilization. Surgical technique involved placement of a single 4.0-mm cortical compression screw across the LT joint, facilitated by use of a temporary intraoperative K-wire ﬁxation. Cancellous bone autograft from the distal radius occasionally was used. Patient proﬁle included average age of 41 years, 64% male, and 64% with workers’ compensation-related injuries. Mean follow-up was 12.7 months. Poor results were observed in 86% of workers’ compensation patients. Complications included local irritation from hardware (36%) requiring an additional procedure for screw removal and persistent postoperative pain (27%). The investigators concluded that LTA achieved overall satisfactory results and should be the treatment of choice for chronic complete LT ligament injuries. A retrospective review of 26 LTA performed on 24 patients by Guidera et al reported reliable and eﬀective results using cancellous bone grafting and temporary K-wire ﬁxation [38]. Primary fusion was achieved in all wrists in an average of 50 days. Results showed that 83% rated pain relief as good to very good, and 80% of patients returned to work. Surgical indications included symptomatic LT instability (77%) and degenerative arthritis (23%). Associated pathology included congenital carpal coalition (17%), TFCC tears (17%), ulnocarpal impaction (12%), and failed prior fusion attempt (8%). Patient proﬁle included an average age of 32 years, 60% male, and 60% with workers’ compensation-related claims. All patients failed conservative

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treatment. Mean follow-up was 28 months. Surgical technique used a dorsal approach, insertion of cancellous graft into a biconcave space created at the LT joint, and stabilization using two 0.045-inch K-wires from the triquetrum to the lunate. Postoperatively, all patients were immobilized in a short arm thumb-spica cast for a minimum of 6 weeks or until radiographic evidence of fusion was apparent. Pins were removed in the ofﬁce at that time. Postoperative range of motion averaged 77%–80% ﬂexion–extension and 91%–95% radioulnar deviation compared with the unaffected side. Complications were few, with one patient developing a complex regional pain syndrome that resolved, and another requiring a single early K-wire removal secondary to pin migration. Based on these ﬁndings, they concluded that the technique of cancellous bone grafting and temporary K-wire ﬁxation provides safe, reliable, and effective results. Nelson et al retrospectively reviewed 22 patients with arthrography-conﬁrmed symptomatic LT ligament tears and found LTA to be a successful procedure [30]. All patients reported signiﬁcant but not complete pain relief and returned to their previous work, and all but one patient believed the surgery was beneﬁcial. Preceding wrist injury was reported in 95% of patients, and associated pathology included TFCC tears in one third of the patients. All patients failed conservative treatment. Patient proﬁle included an age range of 26–62 years, 77% male, and 14% with work-related injuries. Mean follow-up was 23 months. Surgical ﬁxation techniques used 0.062-inch K-wires alone (68%) or Herbert screw supplemented with K-wires (32%). Articular cartilage was removed using curettes, leaving a small rim of cartilage to retain the autologous cancellous bone graft (distal radius or iliac crest) that was used routinely. Postoperative care included removal of K-wires in the ofﬁce at approximately 6 weeks. Cast immobilization was continued until radiographs indicated fusion, and ranged from 6–8 weeks. Fusion rates were analyzed with respect to ﬁxation technique and cast immobilization. Primary fusion was found to be superior to use of Herbert screw plus K-wire ﬁxation (86%) versus K-wires alone (60%). Cast immobilization for a minimum of 6 weeks decreased the rate of nonunion from 58% to 14%. Use of Herbert screw and K-wire ﬁxation in those patients immobilized longer than 6 weeks resulted in union in all patients. Based on these results, the investigators recommended use of Herbert screw and supplemental K-wire ﬁxation followed by cast immobilization for 8 weeks. Kirschenbaum et al reviewed 14 patients who underwent LTA for LT instability [32]. Solid fusion was achieved in 86% of patients at 8 weeks, and 93% were satisﬁed with the results. Based on these results, the investigators conclude that although the long-term effects are unknown, LTA reliably relieves pain while maintaining functional motion and grip strength. Diagnosis was conﬁrmed in all cases by arthrograms, followed by arthroscopy if necessary. Patient proﬁle included an average age of 35 years, 71% male, and 93% with a history of trauma. Average time between onset of symptoms and presentation averaged 24 months. Mean follow-up was 27 months. Surgical technique involved decortication of the LT articulation, leaving the palmar portion of the joint intact to maintain carpal alignment. Multiple K-wires were used for ﬁxation, together with cancellous bone autograft (ie, distal radius or iliac crest). Postoperatively, protected range of motion was initiated at 8 weeks, and protective splinting was continued for 12 weeks on average. K-wires were removed after solid fusion was achieved. Complications were reported in 28% of patients and included pseudarthrosis (14%), persistent pain (7%), and neurapraxia of the dorsal sensory branch of the ulnar nerve (7%). Sandow et al reported successful results of various intercarpal arthrodeses performed in 24 patients using a dowel bone grafting technique [36]. LTA was performed in three of these patients for arthroscopically conﬁrmed instability, and solid fusion resulted in all patients by 6 months. Surgical technique required general anesthesia and involved use of tube saws to achieve an interference ﬁt between the carpals of interest and the harvested iliac crest bone graft. Temporary ﬁxation was achieved using one or more K-wires, removed at approximately 8 weeks. Wrist immobilization was discontinued in all patients by 10 weeks. Complications were few and included reﬂex sympathetic dystrophy in only 4% of patients. Mean follow-up was 14.5 months. The investigators conclude that intercarpal arthrodesis by dowel bone grafting is a precise, reproducible, and technically simple procedure with high fusion rates and few complications. In the largest and most recent case report on surgical treatment of symptomatic LT coalitions, LTA performed on ﬁve patients with 12 Minaar type 1 coalitions yielded predictably good results

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with acceptable eﬀect on wrist motion [21]. Resolution of symptoms was observed in all patients (with one follow-up pending) following LTA. Surgical treatment was performed in 8 of 12 cases and included LTA (n = 5) and proximal row carpectomy (n = 3). Arthrodesis technique involved Herbert screw and K-wire ﬁxation without the use of bone graft. Radiographic evidence of fusion was evident in at least 60% of patients (1 not commented, 1 follow-up pending). Based on their results, the investigators further state that routine use of cancellous bone graft is not necessary. Similarly, two earlier case studies of symptomatic LT coalitions presented four patients who underwent limited intercarpal (LT) fusion with reported resolution of symptoms in all patients [27,28]. Details on their surgical techniques, however, are scant. Con lunotriquetral arthrodesis In contrast, several studies have suggested that LTA is associated with poor fusion rates and unacceptable clinical outcomes [17,26,31,39]. A retrospective review of 22 LTA performed in patients with isolated LT ligament injuries by Shin et al reported unacceptable rates of nonunion (41%), complications (82%), reoperation (64%), and patient satisfaction (57%) using corticocancellous bone grafts combined with several ﬁxation techniques [31]. Surgical indication was isolated LT injury conﬁrmed by direct visualization (ie, arthroscopy or arthrotomy) in all patients. Because diagnosis was delayed 1.2 years on average, 86% of patients were considered to have chronic injuries. Patient proﬁle included an average age of 31 years, 61% male, and 44% with workers’ compensation-related claims. Mean follow-up was 10.5 years. Multiple LTA techniques were used that combined autologous corticocancellous bone graft (68% iliac crest, 32% ipsilateral distal radius) in one of three patterns (68% interposition block, 23% slot graft, 9% winged graft) and secured with various hardware (59% K-wires, 23% Herbert screw, 14% AO compression screw, 4% staples). Length of postoperative immobilization was not mentioned. Results were compared with patients treated with direct ligament repair or reconstruction. Compared with the reconstruction or repair groups, LTA patients complained of signiﬁcantly more pain, weaker grip strength, and less satisfaction overall. In addition to nonunion (not deﬁned), major complications included ulnocarpal impingement (23%) that required ulnar recession and resulted in resolution of pain in all patients, RSD (18%), nerve injury (18%), and pin tract infection (9%). DASH scores for the LTA group were 30, versus 20 for the ligament repair and reconstruction groups. The investigators correctly point out potential sources of selection and treatment bias in this retrospective study that spans a 26-year period. Indications for arthrodesis versus ligament repair or reconstruction were not differentiated, and one could surmise that LTA was selected for patients with more severe injuries and hence portend a worse outcome. The investigators conclude that lunotriquetral ligament repair and not LTA should be the treatment of choice for isolated LT ligament injuries. A retrospective review of LTA performed in 23 patients with painful LT instability by Sennwald et al found a high rate of pseudarthrosis (57%) and concluded that LTA is associated with unpredictable results and should not be considered a routine procedure [39]. Patient proﬁle included an average age of 30 years, 52% male, and 17% with work-related injuries. Mean followup was 28 months. Surgical technique involved removal of subchondral bone using a chisel, followed by placement of two AO compression screws facilitated by temporary K-wire ﬁxation. No bone graft was used. Postoperatively, short arm cast immobilization was continued for approximately 8 weeks. Associated pathology included arthroscopically diagnosed chondromalacia of the ulnar midcarpal joint (triquetral-hamate) in 22% of patients, with 80% of these requiring revision surgery. Pain and radiographic carpal alignment were measured pre- and postoperatively. Results included signiﬁcant relief of pain in all patients, although only 1 of 23 patients (4%) was completely pain-free. At follow-up, 13% of patients remained out of work and 10 months of work was lost on average. Postoperatively, patients with an increased LT angle (>31 ) demonstrated a signiﬁcantly increased loss of working days. In contrast to the ﬁndings of Nelson et al, no correlation was found between the period of immobilization and rate of fusion [30]. The 12 patients with pseudarthrosis underwent a second operation, this time using corticocancellous bone graft from the radius, and successful fusion was achieved in all but one (92%) of these patients. Complications included impingement syndrome (13%) between the triquetrum and hamate necessitating a four-corner fusion, and reﬂex sympathetic dystrophy (4%)

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in one patient. Based on these results, the investigators concluded that LTA is unpredictable and should not be considered a routine procedure. If performed, however, they state that (1) routine use of bone graft is necessary, (2) use of AO lag screw ﬁxation may be inadequate, and (3) midcarpal chondromalacia is a contraindication to LTA and should be treated with a four-corner fusion instead. Vandesande et al retrospectively reviewed 29 patients treated with LTA for chronic LT ligament tears and reported high rates of nonunion (45%), complications (29%), and reoperation (65%) [26]. Nearly half of the patients were dissatisﬁed, and only 59% indicated they would repeat the procedure. Diagnosis was conﬁrmed by arthrography or arthroscopy. Associated pathology was present in half of all patients and included tears of the scapholunate (31%) and TFCC (17%) ligaments. Radial-sided wrist pain, not ulnar, was the chief complaint in 17% of patients. Static VISI deformity was noted in 21% of patients. Patient proﬁle included an average age of 32 years, 55% male, 41% work-related injuries, and a history of trauma in 66% of patients. Surgical ﬁxation techniques varied and included use of a Herbert screw (59%), multiple K-wires (21%), and staples (17%). Autogenous bone grafting was used in 83% of cases and was associated with a higher rate of fusion (53%) versus LTA without bone graft (40%). Fusion following Herbert screw ﬁxation (64%) was higher than that achieved using K-wires (50%) or staples (20%). Subjective outcomes (eg, patient satisfaction) were not found to correlate with objective outcomes (eg, fusion). Loss of work averaged 45 weeks in the fusion group. Complications included reﬂex sympathetic dystrophy (14%), ulnar nerve neuromas (14%), pisotriquetral impingement (10%), and arthroﬁbrosis (3%). Based on these results, they conclude that LTA as a treatment for LT ligament tears with high rates of associated pathology should be reconsidered in lieu of other alternatives (ie, ligamentoplasty, extended arthrodesis).

Range of motion and grip strength Postoperative wrist motion is extremely variable and has been reported to range from 55%– 115% compared with the contralateral, unaﬀected side, with some studies demonstrating increased postoperative radial deviation [25,26,31,32,34,38]. In comparison, it is interesting to recall that patients with congenital lunotriquetral fusion typically have normal wrist range of motion [21,22]. Postoperative grip strength has been reported to range from 51%–93% compared with the unaffected side [7,25,26,30,32,34]. Review of the literature reveals a wide variation in outcomes following LTA. Primary fusion rates have been reported in 43%–100% of patients [38,39]. Need for reoperation has ranged from 0% at 14 months to as high as an estimated 78% at 5-years postoperatively [31,36]. Return to work in 68%–100% of patients has been achieved anywhere from 2 months to 3 years postoperatively [25,26,30,31,38,39]. In general, higher fusion rates have been reported with the combined use of compression screw plus K-wire ﬁxation, bone graft, and sufﬁcient postoperative immobilization for at least 6–8 weeks [25,30,39]. The need for multiple point ﬁxation to enhance rotational stability and fusion rates might be anticipated, given the primarily rotational intercarpal motion observed at the LT joint [9]. It is important to keep in mind that fusion may not always guarantee a good clinical outcome. Vandesande et al found no signiﬁcant correlation between fusion and subjective patient outcome [26]. Painless pseudarthroses and painful solid fusions have been reported [32]. Despite the high union rates reported by Pin et al, 11 of these 11 patients reported unsatisfactory results [20]. Determination of appropriate outcome measures following LTA is therefore essential. Outcomes in patients with workers’ compensation-related injuries in some studies have been uniformly poor [25]. This suggests the potential importance of psychosocial factors and the need to include patient-oriented outcome measures. This observed variable success following LTA is multifactorial. Important factors include limitations inherent to retrospective studies (eg, potential bias), small patient populations resulting from the relative infrequency of injury, variable associated pathology, and diﬀering surgical arthrodesis techniques, surgical indications, and postoperative immobilization regimens. Endpoints frequently cited to gauge the success of LTA (eg, fusion rates, pain relief, complications,

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need for reoperation, return to work) are often subjective and diﬃcult to quantify. For example, accurate assessment of fusion rates using routine radiographs may not be straightforward and postoperative tomograms and CT scans may be necessary [36]. Surgical indications The literature supports the use of LTA for symptomatic LT coalition, chronic LT ligament tears, symptomatic LT instability without static deformity, positive arthrogram for LT tear or temporary relief with LT injection, degenerative LT arthritis, and failure of ligament repair or reconstruction [1,12,21,27,28,30,31,33]. LTA has also been used in combination with scaphotrapeziotrapezoid fusion for the treatment of coincident SL and LT ligament disruption without perilunate dislocation with some success [20]. All patients should demonstrate persistent symptoms with evidence of LT pathology supported by imaging studies before operative intervention. Surgical indication is perhaps the most important determinant of patient outcome. For example, patients with symptomatic congenital LT fusion may have a more predictable and favorable result following LTA versus those with a history of trauma and increased likelihood of pathology not limited to the LT joint. Arthroscopy can be invaluable in this regard. Failure to recognize associated pathology may result in treatment of a global wrist problem with a limited intercarpal arthrodesis, and hence may achieve unsatisfactory results. For example, Vandesande et al reported poor results following LTA when associated pathology was present in more than 50% of patients (31% scapholunate tear, 21% ﬁxed VISI deformity), and concluded that alternative procedures should be considered. Reagan et al noted that patients with poor subjective outcomes following LTA seemed to have persistent symptoms related to other associated injuries rather than to the initial LT injury [7]. Pin et al emphasized the potential importance of distinguishing isolated ligament tear from ulnar impaction syndrome, as the latter may require an ulnar shortening osteotomy in addition to LT joint stabilization [25]. As mentioned earlier, LTA in the presence of midcarpal arthrosis has been associated with poor results, and extended carpal fusion may be more appropriate in such cases [39]. Arthroscopic evaluation may be helpful to verify the diagnosis and identify associated pathology before LTA. Surgical contraindications LTA for the treatment of midcarpal instability with VISI deformity has yielded poor results and is generally not recommended [17,32,38]. This injury pattern may represent a more severe injury to the midcarpal ligaments or chronic attenuation of adjacent ligaments secondary to abnormal stresses following LT ligament injury [38]. Some investigators advocate a capitohamate lunotriquetral fusion in symptomatic patients with a static or dynamic VISI pattern [17]. As mentioned previously, associated midcarpal chondromalacia has been associated with poor results and extended fusions (eg, midcarpal, four-corner) have been recommended for such cases [1,33,39]. In the athlete, use of LTA has been recommended only as a last resort [13]. Arthrodesis technique Strict adherence to basic principles of intercarpal arthrodesis has been emphasized to facilitate successful outcomes. These include restoration and maintenance of normal carpal relationships, decortication and creation of broad cancellous surfaces, and use of densely packed bone graft [1,38]. There is general agreement that hardware ﬁxation is necessary to achieve LTA. Some investigators suggest that completely intraosseous ﬁxation (eg, compression screw) may be superior to temporary ﬁxation devices (eg, K-wires) in providing long-term stability and facilitating fusion [30]. In contrast, others have suggested that intraosseous screws also may promote nonunion by acting as distracting devices with secondary resorption of the interposed bone graft [1]. Compression across the fusion site may be beneﬁcial, but perhaps not at the expense of restoring normal carpal relationships and potentially disturbing adjacent joint mechanics [36]. Other factors that may contribute to nonunion following LTA include the small surface areas available for fusion and potential thermal damage associated with use of power tools [1,36].

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The need for routine bone grafting remains somewhat controversial. Review of the literature reveals studies that advocate routine use of cancellous bone grafting with LTA and those that do not [21,27,38]. In contrast to primary fusion rates of only 43% without the use of bone graft, Sennwald et al reported a high rate of successful secondary fusions (92%) when corticocancellous bone autograft was used [39]. Vandesande et al noted a 13% increase in fusion rates in patients treated with autogenous bone grafting [26]. In contrast, Ritt et al found predictably good results without the use of bone graft for LT coalition and concluded that routine use of bone graft is not necessary [21]. These differing recommendations are based on studies with different surgical indications. Although it is possible that autologous distal radius bone graft harvesting could increase morbidity and postoperative pain following intercarpal arthrodesis, studies have not shown a signiﬁcant effect of bone graft harvest site on clinical outcome [34]. Complications The rate of complication following LTA has been reported to be 4%–57% [25,26,30– 32,36,38,39]. The most commonly encountered complication is nonunion, followed by persistent postoperative pain, complex regional pain syndrome, ulnocarpal impingement, local irritation from retained hardware, nerve injury, tendonitis, and pin tract infections. McAuliffe et al retrospectively reviewed 50 patients who underwent various intercarpal arthrodeses and documented an overall complication rate of 72% [34]. Speciﬁc complications were similar among all types of intercarpal arthrodeses. They also noted a strong association between any complication and poor ultimate outcome.

Summary Lunotriquetral arthrodesis is a technically challenging surgical procedure with variable results reported in the literature. Accurate diagnosis and identiﬁcation of associated pathology used to deﬁne appropriate surgical indications is critical to optimizing successful outcomes. At present, arthroscopy remains the procedure of choice for conﬁrmation of suspected lunotriquetral pathology. Appropriate surgical indications may include symptomatic LT coalitions, chronic LT ligament tears, symptomatic LT instability without static deformity, positive arthrogram for LT tear or temporary relief with LT injection, degenerative LT arthritis, and failure of ligament repair or reconstruction. In contrast, contraindications to LTA may include midcarpal instability with VISI deformity and presence of midcarpal chondromalacia. The wide range of successful outcomes of LTA reported in the literature is multifactorial, and the presence of associated injuries may confound interpretation of results.

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