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Orthopaedics and Trauma Elsevier, ISSN: 1877-1327, http://www.sciencedirect.com/science/journal/18771327 Volume 25, Issue 6, Pages 397-466 (December 2011) 1
Editorial Board, Page i
Mini-Symposium: Spinal Deformity 2
(i) Clinical assessment of scoliosis, Pages 397-402 Adrian Gardner
3
(ii) Scoliosis in children and teenagers, Pages 403-412 Nigel W. Gummerson, Peter A. Millner
4
(iii) Adult degenerative scoliosis, Pages 413-424 Anant D. Tambe, Antony Louis Rex Michael
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(iv) Development and treatment of spinal deformity in patients with neurological or myopathic conditions, Pages 425-434 Athanasios I. Tsirikos
6
(v) Unicompartmental knee arthroplasty, Pages 435-440 S. Thambapillay, G. Chakrabarty
7
(vi) An introduction to hip arthroscopy part one: surgical anatomy and technique, Pages 441-447 Peter D.H. Wall, Jamie S. Brown, Shanmugam Karthikeyan, Matthew Wyse, Damian Griffin
8
(vii) Radiology Quiz: Lower limb amputation stump pain, Pages 448-453 Bahir Almazedi, James J. Rankine
9
(viii) Blount’s disease, Pages 454-461 T. Nunn, P. Rollinson, B. Scott
CME Section 10
CME questions based on the Mini-Symposium on “Spinal Deformity”, Pages 462-463
11
Answers to CME questions based on the Mini-Symposium on “Foot and Ankle”, Page 464
Book Reviews 12
Smart surgeons – smart decisions, Page 465 David Limb
13
Operative techniques in Adult Reconstruction Surgery, Page 465 Chris Brew
14
Operative techniques in pediatric orthopaedics, Pages 465-466 Joshua Bridgens
Orthopaedics and Trauma Orthopaedics and Trauma presents a unique collection of International review articles summarizing the current state of knowledge in orthopaedics. Each issue begins with a focus on a specific area of the orthopaedic knowledge syllabus, covering several related topics in a mini-symposium; other articles complement this to ensure that the breadth of orthopaedic learning is supplemented in a 4 year cycle. To facilitate those requiring evidence of participation in Continuing Professional Development there is a questionnaire linked to the mini-symposium that can be marked and certified in the Editorial office.
Editor-in-Chief D Limb BSc FRCS Ed (Orth) Leeds General Infirmary, Leeds, UK
Editorial Committee M A Farquharson-Roberts (Gosport, UK), I Leslie (Bristol, UK) M Macnicol (Edinburgh, UK), I McDermott (London, UK), J Rankine (Leeds, UK)
Editorial Advisory Board D C Davidson (Australia) J Harris (Australia) G R Velloso (Brazil) P N Soucacos (Greece) A K Mukherjee (India) A Kusakabe (Japan) M-S Moon (Korea) R Castelein (The Netherlands) R K Marti (The Netherlands) G Hooper (New Zealand)
A Thurston (New Zealand) E G Pasion (Philippines) L de Almeida (Portugal) G P Songcharoen (Thailand) R W Bucholz (USA) R W Gaines (USA) S L Weinstein (USA) M Bumbasirevic (former Yugoslavia)
MINI-SYMPOSIUM: SPINAL DEFORMITY
(i) Clinical assessment of scoliosis
disadvantaged by a scoliosis fusion so that other treatments may be appropriate. Past medical history must be sought including current medication including analgesia, any allergies and particularly whether or not they are a smoker, as smoking is a contraindication to fusion surgery. The next stage is the history of the deformity. It is important to know when the deformity was first noticed and what the child first noticed. As there will always be a gap between the initial recognition and clinical presentation, it is important to have an assessment of what the family and the patient think has happened to the deformity since they first noticed it. It may have increased in size or stayed the same and it may have become symptomatic. It is important not to underestimate the cosmetic effect of scoliosis in this age group. Although it may not be mentioned, children are often very concerned about this aspect. Pain may also be a significant problem, as a marker of underlying psychological distress, due to co-existent pathology (such as a tumour), or because the curve is progressing rapidly and the concomitant rotation that occurs can cause quite significant discomfort. This latter is often described as a ‘muscular’ pain, occurring towards the end of the day and worse with exercise. As with all spinal pathology it is important to rule out any red flag symptoms such as night pain, neurological symptoms or signs, rapidly progressing curves or unusual curve patterns. Obviously any history of constitutional symptoms, weight loss or any symptom or sign that makes the clinician ‘feel uncomfortable’ needs to be taken very seriously at this point. It is also important to assess growth which can be done in several ways. The age of menarche correlates with slowing down in spinal and overall skeletal growth.2 Pre-menarchal patients or those with delayed menarche have the potential for significant future growth and thus potential for significant curve size increase before skeletal maturity. It is often noted that there has been a quite significant growth spurt in the year prior to noticing the deformity or presenting to clinic. Finally an assessment of the probable height of the child at skeletal maturity can be made by assessing parental height. A family history of scoliosis on either side of the family should be sought as it is now apparent that there is a significant genetic link to the development of adolescent idiopathic scoliosis. This may give an indicator of the likely behaviour of the curve in the presenting child.3 Clinical examination must be carried out sensitively as the patients are usually adolescent young ladies. Patients must be undressed sufficiently to fully expose the spine and lower limbs. It is best to start with a dynamic assessment of lower limb motor function and patients should be asked to tiptoe, heel walk and single leg dip, as well as an assessment of their gait. Then with the patient facing away standing in a normal comfortable position, expose the entire spine to assess the deformity. As well as the type and shape of deformity seen in the spine, any cutaneous markers of underlying neural axis anomalies such as a sacral pit, hairy tuft etc should be noted. Of course there may be angular kyphosis, trunk shift and compensatory curves due to congenital anomaly and thus the whole spine needs to be taken into account. Curves are characterized by the direction of the convexity, thus a right thoracic curve is a curve of the thoracic spine convex to the right side. This can be associated with prominence of the posterior rib cage on that side which should also be noted. Whether the hips
Adrian Gardner
Abstract Scoliosis is a common paediatric and increasingly common adult problem. Clinical and radiological assessment is the first step in the management. This article outlines how to perform a thorough history and examination of a patient with scoliosis drawing out the differentiating features of idiopathic scoliosis from other varieties such as congenital, neuromuscular, syndromic and adult scoliosis.
Keywords examination; history; radiography; scoliosis
Introduction Scoliosis is a common disorder of children and adults. It may present to many subspecialities and is commonly seen in clinical academic examinations as it can cover a wide spectrum of pathology. This article aims to give a framework of how to assess scoliosis in the clinical setting by history, examination and initial investigations, focussing on the assessment of adolescent idiopathic scoliosis but indicating the differences from congenital scoliosis, neuromuscular or syndromic scoliosis and adult degenerative scoliosis.
Adolescent idiopathic scoliosis The Scoliosis Research Society defines adolescence as being between the ages of 10 and 18.1 However, most children presenting with adolescent idiopathic scoliosis are between 10 and 16. The diagnosis often comes as a complete surprise, causing worry and concern, because parents and carers tend not to see their teenage girls in a state of undress as they would when they were younger. The story “I did not know until my daughter tried on her bridesmaid’s dress how bent she was” is not uncommon. By its very nature most scoliosis is slowly developing and very minor change day by day often passes un-noticed. Thus it is not uncommon for the parents of the child to express a lot of guilt that they have ‘missed the problem’. The child may also have been previously investigated for shoulder problems as scapular winging can be diagnosed due to it being pushed out by the underlying rib hump. As with all orthopaedic patients the history is important. This should include the social history in terms of school, sports, hobbies and other interests and life time education and work aspirations. This is important as scoliosis is, for example, not compatible with military service and high level athletes or dancers may be
Adrian Gardner BM MRCS FRCS (T&O) Consultant Spinal Surgeon, The Royal Orthopaedic Hospital, Bristol Road South, Northfield, Birmingham B31 2AP, UK. Conflict of interest: none.
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are level and whether there is also a leg length discrepancy should also be noted as well as whether the shoulders are level. Trunk shift can be in the coronal plane and can be associated with patients complaining that their hip is out and/or unequal waist creases. The degree of coronal trunk shift is assessed by drawing a vertical line from the vertebral prominence of C7 vertebra and seeing where this falls with regards to the natal cleft; the plumb line test. The Adams forward bend test performed by asking the patient to bend forward fully whilst being examined from behind. This enables the size of the rib hump to be assessed not only along the length of the spine but also from the side if necessary. While thoraco-lumbar or lumbar curves are not associated with a rib hump, they often have a prominence of the paraspinal muscles on the convexity of that curve or loin hump; patients may complain that they have grown an extra muscle. The presence of acne on the back should be noted as this will need to be treated prior to any surgery to reduce the risk of infection. A full neurological examination is performed with the patient lying supine on the couch assessing all dermatomes and myotomes and lower limb tendon reflexes. Abdominal reflexes should be sought an abnormality may be the only abnormal neurological sign suggesting a neural axis abnormality. Leg lengths can be measured at this point if necessary.
Imaging Imaging is the next stage in patient assessment. Initial X-ray views should be of the whole spine standing, both posteroanterior (PA) and lateral views. Previously practice was for the initial X-ray to be AP view as this gives better definition of bony anatomy of the vertebral bodies and PA views at subsequent visits to reduce the radiation dose to sensitive organs. However with better radiation protection and digital imaging we have found that a PA view is entirely satisfactory.4 However it is important that the whole spine standing view includes the pelvis to allow an assessment of any pelvic obliquity and the Risser status, the epiphysis on the superior edge of the ilium which is an indication of skeletal maturity and an indicator of future growth potential. This can also be gauged by assessing whether the triradiate cartilage of the acetabulum is also still open. The standard method of measuring the size of curves is the Cobb method5 as shown in Figure 1. When documenting the Cobb angle it is important that it is also documented which vertebral body end plates were used as the measuring points so that this can be reproduced at a later date if appropriate. However obviously measurement points may change as curves get bigger. The morphology of the spinal deformity is assessed as it was clinically. The curve is defined using the Scoliosis Research Society criteria. The apex of a thoracic curve lies between T2 and the T11/12 disc, of a thoraco-lumbar curve at T12-L1 and a lumbar curve between the L1/2 disc and the L4/5 disc.6 Again the curve is described by the direction of the convexity; thus right thoracic or left thoraco-lumbar curve, see Figure 2 and Figure 3. It is important at this stage to ensure that there are 12 thoracic
Figure 1 The measurement of the Cobb angle. An angle is taken between the end plates of the most angled vertebral bodies to the horizontal.
Figure 2 A right thoracic curve. Note the convention of rotating the image so that left is on the left as would be seen if observing the patient from behind.
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segmentation such as an unsegmented bar. Coronal imbalance can also be assessed by the same method as before, measuring the distance between a vertical line dropped from the spinous process of C7 and the mid-line of the sacrum. The lateral view allows assessment of sagittal imbalance if the whole of the pelvis and femoral heads are visible. This is to see whether from the side the head is over the pelvis or not, which will be covered further in assessment of the adult deformity. The lateral view is also used to assess any kyphosis in the thoracic spine and the size of the rib hump as the ribs will stick out significantly behind the spine. The next stage in assessment is a whole spine MRI scan from the base of the brain to the end of the sacral cul-de-sac looking for any neural axis anomalies which may be the underlying cause of the deformity such as an ArnoldeChiari malformation, a syrinx, a diastem, an osteoid osteoma or an intradural tumour, whether benign or malignant, see Figures 4 and 5. Until the more ready availability of MRI only certain subgroups of Adolescent Idiopathic Scoliosis (AIS) patients would have had an MRI scan, the ‘high risk’ curves. These were the left-sided thoracic curves, painful curves, curves with neurological signs or symptoms, rapidly progressing curves or curves in males. With improving access it is now common practice to obtain an MRI scan in virtually everybody accepting that the potential for finding an abnormality in an otherwise unremarkable right thoracic curve is only approximately 6.9%.7 A further whole spine standing X-ray examination after the MRI allows for assessment of curve progression which may lead to surgical intervention. Surface topography assessment of all patients is also useful using a system such as ISIS 2 which shows surface shape and size of the rib hump. It also lets the patient see what they actually look like from the outside (a potential pre and post-picture), see Figure 6. There may be a place at this stage for isotope bone scans should the
Figure 3 A left thoraco-lumbar curve.
and five lumbar vertebrae and 12 sets of ribs as this may have implications for later on and also to make sure there is no previously unrecognized congenital elements to the curve either in failures of formation such as a hemi-vertebra or failures of
Figure 4 A brain stem tumour (arrowed).
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Figure 5 A cervical cord syrinx (arrowed).
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Figure 6 Surface topography using ISIS 2.
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Figure 6 (continued).
diagnosis of osteoid osteoma need to be ruled out specifically or a CT scan to display the anatomy of the underlying curve at the apex or at the junctional zone where it is difficult to get good X-ray pictures. Traction and bending X-ray views are taken just before surgical intervention and have no role in most situations otherwise. The other big role of the clinical assessment is for the clinician to inform the patient and parents to allay fears and possible misapprehensions that may arise from a variety of opinions obtained from the Internet. It is good practice to point families towards websites of reasonable and reputable organizations such as the Scoliosis Research Society, Scoliosis Association UK and the British Scoliosis Society. Once all this information is in hand then a decision as to what clinical path is followed by the patient and family can then be made with the surgeon, whether this is surgical intervention, bracing or continued observation.
flexibility and correction of the scoliosis can be seen. Other associated problems in the skeletal system such as plagiocephaly (flattening of the skull), cervical torticollis, developmental dysplasia of the hips and talipes equinovarus can be screened for at this point. All congenital scolioses also require an assessment of cardiac function and renal anatomy as again up to 25% will have some sort of cardiac anomaly such as an atrial or ventricular septal defect and renal anomalies such as a duplex kidney or a horseshoe kidney. This arises because failure to fully form or segment the vertebral bodies occurs at the same time and is associated with developmental errors in heart, lungs, kidneys and other major organ systems.8 All congenital and infantile scoliosis patients require whole spine X-rays as previously detailed although in the very young children these will be supine and a whole spine MRI scan is essential because of the much higher association of neural axis anomalies with congenital scoliosis, up to 20%.8 The treatment of congenital scoliosis (to be covered in another article in this series) is dependent on assessment of the future growth potential. Thus as well as whole spine MRI scan, CT scanning of specific areas (e.g. hemi-vertebrae etc) and even the whole spine to look at the anatomy will assist assessment of the possible progression potential of the deformities seen.
Assessment of congenital or infantile scoliosis The assessment of a patient with congenital or infantile scoliosis, which present in much younger children, is not dissimilar. In the very young child it is important to know whether they were premature or not, the amount of time, if any, spent in a Special Care Baby Unit, any issues with regards to failure to thrive and delayed developmental milestones such as walking or toilet training and any other co-morbidities which may have already been identified as part of an overall condition such as the VACTERLS grouping (Vertebral anomalies, Anal atresia, Cardiac defect, most often ventricular septal defect, Tracheo-oEsophageal fistula with oesophageal atresia, Renal abnormalities and Limb abnormalities, most often radial dysplasia). The child’s growth in terms of height and weight should available in the growth chart in the personal child health record. As with the commoner adolescent scoliosis, it is important to record what deformity has been noted, how it was found and what symptoms, if any, are associated with it. The examination is similar, documenting the number and direction of the curves and an assessment of neurological function and any cutaneous markers of an underlying spinal dysraphism such as a sacral pit or hairy tuft. If the child is suspended unsupported from the axillae the degree of
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Assessment of neuromuscular and syndromic scoliosis The assessment of neuromuscular and/or syndromic scoliosis presents different problems. They can best be thought of as either a spine that is being pulled over by unbalanced spasticity such as in, cerebral palsy or a spine that is falling over due to lack of muscular support such as is seen in spinal muscular atrophy or Duchenne’s muscular dystrophy. The children usually present when already confined to a wheelchair. The clinical issues in both circumstances are very similar in that there is a usually a quite marked, long C shaped thoraco-lumbar curve. This unbalances the pelvis causing sitting balance problems with unequal weight bearing on the buttocks, giving rise to skin problems and pressure sores. In the concavity of the curve there can be costo-iliac impingement; the rib
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margin contacts the pelvis which can be very painful. There can also be problems with skin hygiene and skin breakdown in the skin fold within the concavity of the curve. Management will be based on the individual child’s problems and considering how spinal stabilization would help them. For example if the spine is so unbalanced that the child is having to use one arm for support themselves, they are significantly functionally disabled because of the effective loss of an arm for anything other than support. Obviously if a child has a significant mental retardation as part of the underlying syndrome then it is important to include the parent or carer’s assessment of the child’s daily needs and an assessment from school or school physiotherapist can be very helpful. An assessment of the hips is mandatory to confirm whether they are located in joint and if dislocated whether they are painful or not. Whole spine X-rays are performed although weight bearing X-rays are done sitting, which may make the visualization of the lower part of the spine very difficult. Thus a compromise between sitting and/or supine X-rays may need to be made. It is important here to make an assessment of pelvic obliquity and the hip joints. The more syndromic scoliosis is often associated with significant cardiac and cardio-respiratory morbidity such as the cardiomyopathy seen in Duchenne’s muscular dystrophy. Thus a formal cardiac assessment will be required prior to considering surgical intervention. Pulmonary function testing is also an appropriate investigation as they are at higher risk of requiring intensive care. It may also make the difference in certain groups such as cerebral palsy as to whether it is safe to perform a thoracotomy or not.
surgical reconstruction of lumbar lordosis and sagittal alignment. As for other body systems the assessment is very similar to the medical and anaesthetic assessment for any major operation in the older population. In the adult group it is important to find out whether the patient smokes or not, as smoking is a contraindication to spinal fusion given the increased rate of pseudarthrosis seen in the active smoker.
Conclusion Scoliosis is a common problem. As with all orthopaedic problems history and examination are paramount followed by a proper assessment of the appropriate radiographs and other investigations. It may be necessary to assess a patient over several outpatient visits, looking for progression of the curve prior to intervention. A
REFERENCES 1 http://www.srs.org/patients/adolescent/ (accessed 27 Jun 2011). 2 DiMeglio A, Canavese F, Charles YP. Growth and adolescent idiopathic scoliosis: when and how much? J Pediatr Orthop 2011; 31(suppl 1): S28e36. 3 Miller NH. Genetics of familial idiopathic scoliosis. Clin Orthop Relat Res 2007; 462: 6e10. 4 Ronckers CM, Land CE, Miller JS, Stovall M, Lonstein JE, Doody MM. Cancer mortality among women frequently exposed to radiographic examinations for spinal disorders. Radiat Res 2010; 174: 83e90. 5 Cobb JR. Outline for the study of scoliosis. American Academy of Orthopaedic Surgeons Instructional Course Lectures 1948; 5: 261. 6 http://etext.srs.org/book/ (accessed 27 Jun 2011). 7 Richards BS, Sucato DJ, Johnston CE, et al. Right thoracic curves in presumed adolescent idiopathic scoliosis: which clinical and radiographic findings correlate with a preoperative abnormal magnetic resonance image? Spine 2010; 35: 1855e60. 8 Beals R, Robbins J, Rolfe B. Anomalies associated with vertebral malformations. Spine 1993; 18: 1329e32.
Adult scoliosis Adult scoliosis is usually a sagittal plane deformity with loss of lordosis and falling forwards rather than the primarily coronal plane deformity seen in adolescent idiopathic scoliosis. Thus the clinical presentation is significantly different. Patients may present with problems of fatigue pain as it takes a much greater effort to hold the body upright if out of balance and off the centre of gravity. They may also present with radicular pain from the concavity of the curve and significant back pain. Clinical examination is much more that of a degenerate spine including assessment of radicular symptoms and signs but also of the overall alignment of the spine in both planes. It is important to assess the hips as elderly people with arthritic spines may also have arthritic hips. X-ray examination is by a whole spine PA standing view and a whole spine lateral view including the pelvis and femoral heads to assess pelvic incidence, which is necessary for the proper
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USEFUL WEBSITES www.srs.org Scoliosis Research Society. www.sauk.org.uk Scoliosis Association UK. www.britscoliosissoc.ac.uk British Scoliosis Society.
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(ii) Wrist fractures
These confirmed to the medical profession that these injuries were true fractures, and that most were dorsally displaced. Further clinical descriptions ensued. Dr John Rhea Barton described a shearing-type fracture in 1838, RW Smith of Dublin described a fracture featuring palmar displacement in 1847, yet it would be more than a century before it was realized that fractures of the distal radius could be more than simple extra-articular injuries.1
Douglas A Campbell Tamsin C Wilkinson
Abstract Wrist fractures are seen commonly in everyday orthopaedic practice. This article discusses many of the key areas around recognition, understanding, management and current opinion on fractures involving the distal radius and distal ulna.
Mechanism of injury & biomechanics Most commonly, injuries occur after a simple fall from standing height. Rarely do clinicians take any more detailed history. Yet much information can be gained from asking patients to “describe their fall”. It is natural to pronate the forearm as you fall forwards, and supinate it as you fall backwards. Impact on the pronated forearm is likely to be on the radial side of the wrist, whilst that on the supinated forearm is likely to be on the ulnar side of the wrist. This information stimulates thought as to which other associated structures could be injured during the fall. A fall forwards will focus the examination on the radial structures in the wrist; a fall backwards will draw attention to the ulnar structures. Almost all distal radius fractures (apart from dorsal rim avulsion fractures) can be produced by hyperextension of the wrist.2 Bending forces tend to occur in low-energy falls and typically produce dorsal displacement. Shearing forces disrupt the ligamentous connections of the wrist and produce unstable ‘fracture-dislocations’, whilst axial loading, high-energy injuries compress the articular surface and cause fragments of joint surface to be impacted. Important work, published by Rikli and Regazzoni, on load transfer across the wrist described the existence of three separate structural ‘columns’ within the wrist.3 This ‘3 column concept’ highlights not only how the intact wrist functions, but also provides clear mechanical guidance on how best to reconstruct fractures in this area. The radius has both a ‘radial’ and ‘intermediate’ column, and the ulna represents the third column (Figure 1). The understanding of this concept allows the surgeon
Keywords fracture; outcome; radius; ulna; wrist
History & nomenclature Although Abraham Colles is credited as the father figure and progenitor of distal radius fracture recognition and management, the French physician, JL Petit, first suggested in 1705 that posttraumatic deformity of the wrist may not be due to dislocation (as was commonly thought), but was actually caused by fracture. These ideas were confirmed in the writings of Claude Pouteau (published in 1783 after his death) who stated; “These fractures are most often taken for contusions, luxations incomplete, or for separation of the radius from the ulna at their junction near the wrist” Abraham Colles published his landmark work in 1814 and highlighted the reasons why so much debate had existed about the true nature of the injury when he stated; “.the absence of crepitus and of the other usual symptoms of fracture rendered the diagnosis extremely difficult..” The physical signs of distal radius fracture did not correlate with those of other long bone fractures e most likely due to impaction and relative ‘stability’ of the fragments in the displaced position. The major difficulty for Colles and his contemporaries was that they were describing a fracture 80 years before the discovery of X-rays e which did not occur until 1895. Considering contemporary investigations and imaging, the continuing use of the eponym ‘Colles fracture’ in modern surgical practice can be seen to be potentially inaccurate and perhaps even inappropriate. Dupuytren contributed much to the confirmation that these injuries were fractures, not dislocations, in the publication of the results of his post-mortem dissections in the mid 19th century.
Radial Column Intermediate column
Ulnar Column
Douglas A Campbell ChM FRCS(Ed) FRCS(Orth) FFSEM(UK) Consultant Hand and Wrist Surgeon, Dept of Trauma & Orthopaedic Surgery, Leeds Teaching Hospitals NHS Trust, Great George Street, Leeds, UK. Conflicts of interests: none. Tamsin C Wilkinson FRCS(Tr & Orth) Specialist Registrar, Dept of Trauma & Orthopaedic Surgery, Leeds Teaching Hospitals NHS Trust, Great George Street, Leeds, UK. Conflicts of interests: none.
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Figure 1 The three column concept of Rickli & Regazzoni.
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Extra-articular fractures of the distal radius
to think about ‘rebuilding’ the fragmented wrist in a logical and natural manner and also emphasizes the importance of distal ulnar injuries (see later). Indeed, this concept has also been pivotal in the design of anatomic implants for both the distal radius and ulna.4 The intermediate column is the major load-bearing column of the wrist, confirmed by the dense subchondral bone seen in X-rays of the intact radius. This also explains its involvement in ‘dye-punch’ articular depression injuries. In addition to being a central structural column, the intermediate column also provides the radial component of the distal radioulnar joint (DRUJ) e the sigmoid notch. The bone quality in this distal ulnar corner of the radius is universally good (as a result of its function) and, by virtue of its involvement in both flexion/extension and forearm rotation movements, forms the key area when planning surgical fracture reconstruction. Consequently, surgical reconstruction of the fractured distal radius will concentrate on restoring the integrity and shape of the intermediate column (together with the orientation of the two associated joint surfaces) before restoring the buttressing function of the radial column, and the pivotal function of the distal ulna.
An extra-articular fracture involves neither the radiocarpal nor distal radioulnar joint surfaces. Typically metaphyseal, these injuries classically occur as low-energy bending injuries (Figure 2). Undisplaced fractures should be managed in a simple below elbow cast for 6 weeks, with regular radiological review and cast inspection. Significantly displaced or ‘off-ended’ fractures (Figure 3) demand reduction (preferably closed) and stabilization, usually using Kirschner wires, although open reduction and internal fixation with anatomic palmar plates are gaining popularity e particularly when the wearing of a cast would threaten independence or the pursuit of employment.9 Debate exists as to how best to manage those fractures that are displaced enough to be considered for reduction in some individuals, but not in others, dependent on other co-morbidities and functional demands. There is no clear solution and it may be very difficult, at the outset of treatment, to predict which mildly displaced fractures will cause later functional disturbance. There are a multitude of studies demonstrating significant functional impairment associated with malunion, with evidence of reduced range of motion, grip strength and manual dexterity in malaligned distal radius fractures. However, there are equally valid studies refuting these findings, with little loss of motion or grip strength reported. A recent paper by Forward et al has shown that although patients with malalignment of the distal radius do demonstrate degenerative change radiographically at long-term follow up, this is not related to functional impairment, despite measurable loss of grip strength in these wrists.10 Because there is no consistent message regarding the outcome of malalignment, the concept of an “acceptable reduction” is difficult to define. Certain clear guidelines do exist, however. A recent review of the literature has suggested that restoring radial length to within 2 mm and articular congruency to within 2 mm, improves functional outcome. There is less consensus regarding the importance of restoring dorsal/palmar tilt, with the suggestion that tilt should be restored in the presence of carpal malalignment but can, in some circumstances, be considered acceptable.11 Radial length seems to be a useful predictor of outcome. The short radius will both increase the load borne through the distal ulna and triangular fibrocartilage complex (TFCC) e often by threefold or more e and results in subluxation of the DRUJ. In addition, radial shortening increases the tension in the TFCC, effectively ‘tenting’ it over the distal ulna, with resulting stiffness of the DRUJ and loss of prono-supination (Figure 4).12 This has been shown to correlate with a poor functional outcome. Dorsal tilt will shift the load borne through the radial surface to the dorsal rim, resulting in an increased force per unit area,13 and early degeneration (Figure 5).10 It has also been shown to produce asymmetric increase in TFCC tension and suggests resulting instability.12 DRUJ incongruity also occurs as a result of ‘tilting’ of the sigmoid notch, with resulting loss of prono-supination.14 Radial translation of the distal fragment will result in slackening of the interosseous membrane and potential DRUJ instability without TFCC injury.
Classification Many different authors have produced a multitude of different classification systems e each claiming to describe fracture patterns clearly and reproducibly, and each claiming to help with either treatment planning or outcome prediction. We do not intend to describe each of these in detail in this article, but there are some principles that can be taken from a variety of classification systems. In 1967, Frykman published a classification system that was important in being the first to recognize the involvement (and relevance) of injuries to the distal ulna.5 The Melone system (1993) identified the importance of fragmentation patterns and articular involvement and the AO Comprehensive Classification (1990) described three basic categories of fracture for all bones (Type A e extra articular; Type B e partial articular; Type C e complete articular), which correspond to bending, shear and axial forces. This is a useful categorization, but is difficult to administer reproducibly at the level of sub-types. Fernandez and Jupiter expanded the three basic categories of fracture patterns by adding carpal avulsions and high-energy mixed patterns when they described the Universal System in 1997.6 Further work is now underway assessing the location of fracture lines in relation to the origins of the extrinsic ligaments. Separate classifications of distal ulnar fractures have also been described and are useful in understanding the impact of fracture patterns on both stability and congruity of the DRUJ.7 When considering the classification of a wrist fracture, it is critical to understand the individual personality of each injury. This will include the presence of articular injury, fragment displacement, instability, soft tissue injury, associated injuries, distal ulnar injury and individual patient characteristics. All of these will have an influence on both the management decisions and the outcome. Prognostically, anatomic reduction is still felt to be important, but the necessity for this is questionable in the low-demand population.8
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Insufficiency fractures in the elderly The increasing cohort of patients over 60 years of age in today’s society brings a number of challenges. This group of patients was
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Figure 2 Typical extra-articular bending fracture with associated ulnar styloid fracture.
Figure 3 Displaced extra-articular distal radius fracture.
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Figure 5 Significant dorsal tilt.
complications associated with dorsal plates, such as tendon irritation and loss of flexion due to dorsal scarring. The introduction of angularly stable screws or smooth pins (“locking” screws) into the more dense subchondral bone allows the shape of the implant to be utilized to achieve reduction (Figure 6).17 Contemporary angularly stable implants now “lock” on both sides of the fracture, providing an even more stable solution in osteoporotic bone. The negative impact of surgery in this age group has also diminished as general health has improved, anaesthetic techniques (which are often regional) have become safer, and social support in the postoperative period has become greater. Patients return to independence in a shorter timescale and complications, in the form of continuing disability as a result of malunion, are seen less frequently.9 Whilst this seems to critics to be an aggressive method of management for this age group, protagonists would argue that the clinical results justify a surgical approach.
Figure 4 Significant radial shortening.
previously both chronologically and biologically elderly, but is now maintaining fitness and activity levels for many years after retirement. Not only do this group live independently for longer, they also continue to contribute to society in employment and child-care. Consequently, functionally limiting wrist fractures can change them from contributor to dependent.15 Fracture patterns in this group are usually extra-articular metaphyseal bending fractures, although injuries can involve both the distal radius and ulna. The general fitness and functional demands of an individual will dictate the degree of intervention and the accuracy of reduction that is desirable. Patients with low functional demands will often have a good functional outcome despite significant clinical and radiological deformity, whereas physiologically younger patients with high functional demands at the time of injury are less tolerant of malunion.8 The advent of angularly stable anatomic implants designed for application on the palmar surface of the distal radius has dramatically altered the way these patients can be managed.16 The palmar application of precontoured plates avoids the
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Articular fractures of the distal radius Articular fractures involve the harder subchondral bone and therefore usually result from a greater energy of injury. Consequently, these fractures are seen more frequently in young, active adults. This presents a particular challenge because these
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Figure 6 Indirect reduction and internal fixation of displaced distal radius fracture in osteoporotic bone.
rupture of the extensor tendons.21 Improvements in the surface finish of the implants reduced these complications but did not eradicate them.22 At the same time, developments in implant technology occurred to allow a larger number of fracture patterns to be stabilized with implants applied on the palmar surface of the distal radius. Reduction was achieved by closed, open or indirect methods, and the implant (which must be angularly stable) could be used to stabilize the reduction.23 The potential for irritation of the flexor tendons is significantly less on the palmar surface, as long as the plate is correctly positioned. The ‘watershed line’ is the most volar part of the volar surface of the distal radius and represents the attachment of the volar wrist capsule. The strong volar extrinsic wrist ligaments merge with the capsule and take origin from the radius at this point. If the implant is positioned so that it protrudes distal to the watershed line, the flexor tendons are at risk of irritation and attrition rupture.23 Proximal to the watershed line, the flexor tendons are shielded from the implant by pronator quadratus. Consequently, surgical technique is critical in positioning the implant correctly at the start of fixation. Not all fracture patterns can be stabilized with an implant placed on the volar surface of the distal radius. Whilst the development of anatomic (shaped) implants has undoubtedly increased the spectrum of fracture patterns manageable via this approach, there still remain certain fracture patterns which demand a dorsal approach. The most common type of fracture pattern requiring a dorsal approach is the displaced dorso-ulnar fragment, which forms part of both the radiolunate joint and sigmoid notch. The orientation of the dorsal extrinsic wrist ligaments is such that closed manipulation and reduction by ligamentotaxis is not possible for these fragments. Since they form such a critical part of the radius, accurate and stable reduction is essential. A dorsal approach may be required in such cases. Angular stability is produced in an implant when the threaded head of the screw inserts into a threaded hole in the plate. This
individuals had perfect wrist function and high demands at the time of their injury. They expect to be able to return to their preinjury activities. The frequently high-energy modes of injury (sport, traffic accidents, falls from height, etc) also increase the incidence of associated injuries e which may have a significant impact on the overall outcome. Articular fractures involve the radiocarpal joint, the distal radioulnar joint or both (Figure 7). The functional impact of diminished forearm rotation is greater than diminished flexion/ extension, so great care should be taken in identifying and treating articular fractures of the DRUJ. This area of the distal radius is the keystone of success in managing these injuries.18 Articular fractures are generally considered to recover best if anatomical reduction and stabilization is performed at an early stage to allow functional active range of motion rehabilitation. The historical work of Knirk and Jupiter19 recommended that any steps in the articular surface greater than 2 mm should be reduced as these provoke almost certain early degenerative change. This study, whilst often quoted in the literature over the past 20 years, has now been questioned by the senior author himself and further investigation with modern imaging techniques is required before this question can be authoritatively answered. When planning the surgical reduction and fixation of an articular fracture, a choice of surgical approaches exists. Prior to the introduction of palmar anatomic locking plates in the past decade, the dorsal approach was preferred.20 This was a logical approach, since most fractures featured dorsal comminution and effective bone loss. Direct elevation of these fragments was required, and bone grafting was necessary to prevent early redisplacement. However, implants applied to the dorsal surface of the radius often gave rise to significant complications of tendon irritation and rupture, in view of the close anatomical proximity of these gliding structures to the surface of the metal implant. In one series, 5% of patients required plate removal for tenosynovitis and a further 7% of patients developed attrition
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Figure 7 Displaced intra-articular fracture of distal radius treated by open reduction and internal fixation. (Note: co-existent fracture of ulnar styloid and middle metacarpal).
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demands that the hole for the screw is drilled precisely perpendicular to the threaded plate hole, or the screw will not fit. As a result, the location and position of each screw are fixed relative to the plate. The newest concept of locking implants is to allow a locked screw to be inserted in different trajectories through the same screw hole, so as to aim accurately for smaller bone fragments, rather than have the screw path pre-dictated. This ‘variable angle’ technology still provides angular stability when tightened, but there is a greater choice of screw position within the fragments.9 Great care must be taken when using ‘variable angle’ screws since they can more easily be placed in the joint or into conflict with each other. The recent advances in locking plates have removed the focus from alternative techniques for managing distal radius fractures. However, for those fractures which are too fragmented to be managed by internal fixation, closed reduction and K-wire fixation24 or external fixation remain viable options.25 External fixation can either bridge the radiocarpal joint, with pins located in the shaft of the radius and index metacarpal (Figure 8), or be nonbridging if the size of the distal fragment allows pin placement within it. Bridging fixation relies on ligamentotaxis to reduce fracture fragments, and therefore cannot be used to reduce an
articular fragment with no soft tissue attachment, such as the dye punch fragment in the lunate fossa. Techniques to reduce these fragments using arthroscopic assistance or mini-open reduction with supplementary K-wire fixation or bone grafting have been shown to be effective.26 Such augmentation of the external fixator will also enhance the stability of the fracture, allowing distraction through the frame to be reduced at an earlier stage. Complications associated with external fixation are numerous. In addition to pin tract infection, injury to the superficial branch of the radial nerve, stiffness of the radiocarpal joint and fingers, and Complex Regional Pain Syndrome are well documented, but can be reduced with meticulous surgical technique.27 Intra-articular fractures of the distal radius remain difficult to treat and although recent papers tend to support internal fixation,28 there is a paucity of level 1 evidence to support one technique over another,29,30 provided the articular surface has been adequately reduced.
Imaging Plain radiographs are usually available when patients are first seen in an Emergency Department. Surgeons are also used to requesting CT scans to further understand the fracture pattern and fragment displacement. It is important to look critically at plain radiographs to obtain the maximum amount of information, because these are the only investigations available during surgery and surgeons must remain conversant with the more subtle pieces of information available on these images. A thorough knowledge of radiographic anatomy is essential when reconstructing fractures of the distal radius and ulna. Similarly, a 3D appreciation of the geometry of each of the bones and how they articulate is also necessary. Almost all wrist fractures are easier to understand and visualize when a CT scan is available in addition to plain radiographs. Once the fracture pattern has been fully understood on CT data, it is recommended that the surgeon returns to once more examine the plain radiographs. This will help to assimilate knowledge of the radiographic appearance of common fracture patterns, so that plain radiography (either in the form of plain X-rays or image intensifier views) becomes more meaningful (Figure 9). A lateral plain radiograph of the wrist will not reveal any information other than the condition of the lunate fossa and sigmoid notch of the distal radius. The scaphoid fossa cannot be seen in this view. A 20 inclined lateral will, however, provide this information and should form a routine part of preoperative screening. Similarly, a PA plain radiograph does not provide any information on whether or not subchondral screws have penetrated the joint surface. A 15 inclined PA view will be parallel to the joint surface and give accurate information on screw penetration and joint congruity.31 Other more sophisticated imaging, such as MR arthrography, is extremely useful when assessing associated injuries but will provide little assistance in managing the skeletal elements of the injury.
Distal ulnar fractures The distal ulna forms the third column of the wrist. Fractures of this bone have, until recently, been largely ignored. Fractures
Figure 8 Comminuted articular fracture treated by non-distracted external fixation with supplementary K-wire.
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Figure 9 Lateral x-ray and CT scan demonstrating ‘dye punch’ fracture.
of the ulnar styloid are commonly seen, but their relevance is poorly understood. The distal ulna can fracture in several different patterns; simple neck, comminuted head, simple neck þ ulnar styloid and multifragmentary extending into the distal shaft.7 The importance of distal ulnar fractures is a consequence of their contribution to both stability and congruity of the DRUJ. Not all distal ulnar fractures require active treatment. Indeed, only the minority of these fractures demand intervention. To identify which fractures require treatment, it is crucial to understand how the DRUJ is constructed and how it functions. Stability will be threatened by either displaced fractures of the articular surface, or avulsion of the stabilizing structures (most frequently the foveal attachment of the TFCC). Under load, the styloid attachment of the TFCC contributes little to stability, whilst the foveal attachment contributes greatly to DRUJ stability. This explains why fractures of the tip of the styloid are so innocuous, whilst fractures at the base are significant contributors to instability.32 It is mandatory to assess the stability of the DRUJ after performing any fixation of a distal radius fracture. Stability is assessed by firmly grasping the distal radius in one hand and, with the patient’s elbow flexed to at least 90 and in neutral forearm rotation, grasp the distal ulna in the other examining hand. Passive AP glide can then be compared to the opposite, uninjured hand, which will give information about the stability of the DRUJ. This clinical test can be made more sensitive by performing distal ulnar AP glide with the wrist in ulnar deviation, then radial deviation. The AP glide should tighten when the wrist is in radial deviation.
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Joint congruity can be assessed by plain radiography and by CT scan. Accurate reduction and stabilization is necessary in displaced injuries to restore the ulna as both a pivot for forearm rotation and a stable buttress for contact with the sigmoid notch of the distal radius. Fractures involving both distal radius and ulna are often misunderstood and managed as a radial fracture alone. These are forearm fractures that happen to be near the wrist, and should be managed in the same way as a diaphyseal injury of both bones (Figure 10).7 When distal ulnar fractures are stabilized by secure internal fixation, early rehabilitation can involve active and passive forearm rotation movements. This reduces the risk of scarring of the interosseous ligament and consequent permanent restriction of movement. Ulnar styloid fractures are frequently seen, but rarely require active treatment. The significance of the attachment of the deep fibres of the TFCC in the ulnar fovea means that oblique basistyloid fractures are the most likely type of ulnar styloid fracture to require active stabilization. Clinical examination of DRUJ stability, as described above, will guide the surgeon.
Incidence & identification of associated injuries Arthroscopic studies have proved that associated injuries occur frequently. A study by Richards et al identified TFCC tears in 53% of intra-articular fractures, scapholunate ligament tears in 21.5% of intra-articular fractures and lunatotriquetral ligament injuries in 6.7% of intra-articular fractures and 13.3% of extra-
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Figure 11 Displaced radial styloid fragment, incompletely reduced with coexistent scapholunate diastasis.
a separate radial styloid fragment e particularly if displaced e will temporarily leave the scaphoid unsupported by the scaphoid fossa, whilst the lunate remains stable within the radiolunate joint (Figure 11). The scapholunate ligament is frequently injured in this fracture pattern and can be readily recognized if sought. Alteration in carpal radiographic anatomy will raise suspicion of an intrinsic ligament injury. Fracture around the distal ulna will highlight the potential disruption in integrity of the DRUJ stabilizing structures. Clinical examination will determine stability. It remains unusual, however, to identify an associated injury in the acute setting. They are usually discovered in the weeks after injury when rehabilitation is unexpectedly poor, or physical signs reveal themselves. Clinicians treating wrist fractures must always consider possible associated injuries during each consultation until rehabilitation is complete.
Figure 10 Fractures of distal radius and ulna treated by open reduction and internal fixation.
articular fractures.33 Yet function-limiting problems are rarely seen in the long-term in untreated cases. The difficulty therefore lies in the identification of such injuries and the decision-making around which ones demand treatment. A dorsal, open approach, when performing internal fixation, will allow direct inspection of the intrinsic ligaments, but these approaches are less frequently performed with modern implants. Consequently, the clinician must have a high index of suspicion when assessing wrist fractures, and look for any clue or suggestion of associated injury. Certain fracture patterns give rise to a greater risk of certain associated injuries. For example,
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Children’s fractures Fractures of the distal radius are common in childhood, and almost universally result in a normal functional outcome. The majority of fractures are buckle or torus fractures (Figure 12), which can be adequately treated by splinting for 3 weeks, the splint being removed by the parents.34 Rarely do these fractures require surgical intervention, due to the inherent stability of buckle fractures and the large remodelling potential, although closed manipulation is indicated where unacceptable alignment of greater than 20 of angulation in the flexion/extension plane
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due to the proximity of the distal radial physis, will correct if sufficient time for growth remains. Malunion of less than 20 will take up to 2 years to correct, so this must be borne in mind when treating older children. Care must be taken to identify a Galeazzi fracture-dislocation, since these injuries demand early reduction and stabilization. Growth will correct the radial deformity in time in many cases, but DRUJ biomechanics may suffer irreversible damage before this correction is complete. Growth arrest is uncommon, complicating approximately 4% of all physeal injuries of the distal radius, but up to 50% of displaced physeal fractures of the ulna.35 It may be partial or complete. Partial arrest will result in progressive deformity over time, and the timing of any surgical intervention needs careful thought. In rare cases, repeat osteotomy is required as growth (and progressive deformity) continues after the first procedure (Figure 13).
Complications Complications after wrist fracture can be classified into: Early (occurring before the normal fracture healing time) Medium term (occurring after normal fracture healing time but before rehabilitation is complete) Late (occurring after healing & rehabilitation) Early complications include - median nerve injury (disturbance from the time of injury) - carpal tunnel syndrome (caused by oedema in the first hours after injury) - redisplacement (after manipulation or surgical treatment) - associated injury
Figure 12 Typical buckle fracture in distal radius of 10 year old child.
or 10 of radial/ulnar deviation exists. The majority of fractures involve the distal radial metaphysis, but when the physis is involved, care must be taken not to further injure the growth plate by repeated forceful manipulation or by introducing blunt or threaded K-wire. Younger children heal quickly and also have a significant capacity for remodelling. Malunion is common, but
Figure 13 Complete physeal arrest treated by radial lengthening and ulnar shortening osteotomies.
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Medium term complications include - delayed or non union (rare except in both bone or open fractures) - stiffness and loss of motion (wrist and/or digits) - complex regional pain syndrome (type I) e CRPS I - ulnar wrist pain Long-term complications include - malunion - osteoarthritis - permanent loss of motion - cosmetic deformity Each specific complication has its own specific management. The awareness of potential complications is the best tool for avoiding them.
and distal radioulnar joints optimizes function, whilst the appreciation of the functional importance of the distal ulna and its soft tissue attachments should avoid undertreatment when these structures are involved in the injury. A
REFERENCES 1 Imrie M, Yao J. Distal radius fractures: a historical perspective. Fractures and injuries of the distal radius and carpus. Elsevier, 2009. pp. 1e10. 2 Pechlaner S, Kathrein A, Gabl M, et al. Distal radius fractures and concomitant lesions. Experimental studies concerning the pathomechanism. Handchir Mikrochir Plast Chir 2002; 34: 150e7. 3 Rickli DA, Honigmann P, Babst R, Cristalli A, Morlock MM, Mittlmeier T. Intra-articular pressure measurements in the radioulnocarpal joint using a novel sensor: in vitro and in vivo results. J Hand Surg Am 2007; 32A: 67e75. 4 Rikli DA, Regazzoni P. Fractures of the distal end of the radius treated by internal fixation and early function. A preliminary report of 20 cases. J Bone Joint Surg Br 1996; 78-B: 588e92. 5 Frykman G. Fractures of the distal radius, including sequelae e shoulder-hand-finger syndrome, disturbance of the distal radioulnar joint and impairment of nerve function: a clinical and experimental study. Acta Orthop Scand 1967;(suppl 108): 1e155. 6 Jupiter JB, Fernandez FL. Comparative classification for fractures of the distal end of the radius. J Hand Surg Am 1997; 22: 563e71. 7 Ring D, McCarty LP, Campbell D, Jupiter JB. Condylar blade plate fixation of unstable fractures of the distal ulna associated with fracture of the distal radius. J Hand Surg Am 2004; 29: 103e9. 8 Young BT, Rayan GM. Outcome following nonoperative treatment of displaced distal radius fractures in low-demand patients older than 60 years. J Hand Surg Am 2000; 25: 19e28. 9 Downing ND, Karantana A. A revolution in the management of fractures of the distal radius? J Bone Joint Surg Br 2008; 90-B: 1271e5. 10 Forward DP, Davis TRC, Sithole JS. Do young patients with malunited fractures of the distal radius inevitably develop symptomatic posttraumatic osteoarthritis? J Bone Joint Surg Br 2008; 90-B: 629e37. 11 Ng CY, McQueen MM. What are the radiological predictors of functional outcome following fractures of the distal radius? J Bone Joint Surg Br 2011; 93-B: 145e50. 12 Adams B. Effects of radial deformity on distal radioulnar joint mechanics. J Hand Surg Am 1993; 18A: 492e8. 13 Short WH, Palmer AK, Werner FW, Murphy DJ. A biomechanical study of distal radial fractures. J Hand Surg Am 1987; 12: 529e43. 14 Kihara H, Palmer AK, Werner FW, Short WH, Fortino MD. The effect of dorsally angulated distal radius fractures on distal radioulnar joint congruency and forearm rotation. J Hand Surg Am 1996; 21: 40e7. 15 Gehrmann SV, Windolf JW, Kaufmann RA. Distal radius fracture management in elderly patients: a literature review. J Hand Surg Am 2008; 33A: 421e9. 16 Larson AN, Rizzo M. Locking plate technology and its applications in upper extremity fracture care. Hand Clin 2007; 23: 269e78. 17 Yoshiro K. Condylar stabilizing technique with AO/ASIF distal radius plate for colles’ fracture associated with osteoporosis. Tech Hand Up Extrem Surg 2002; 6: 205e8. 18 Stoffelen D, De Smet L, Broos P. The importance of the distal radioulnar joint in distal radial fractures. J Hand Surg Br 1998; 23-B: 507e11.
Outcome Outcome is difficult to measure after wrist fractures. The same radiographic fracture pattern treated in the same way by the same surgeon will often produce widely different results in different individuals. Various objective measurements of functional outcome have been described, from the much-used Gartland & Werley demerit scoring system (1951) to more modern assessments of global upper limb function (DASH) and general wellbeing (SF-36). None of these are reliable enough to critically appraise comparative management methods. The Cochrane database has clearly stated that insufficient evidence exists in even the most scientifically rigorous clinical studies, to ascertain the ‘best’ treatment methods for wrist fractures.29,30 As a result, we are condemned to continue managing these injuries with our favourite techniques (or, alternatively, avoiding our least favourite techniques) insecure in our knowledge that we are providing the ‘best’ treatment. There are many excellent pieces of scientific and clinical evidence available when making decisions about fracture management around the wrist, but the variability of our patients (and e to a degree e the variability of our clinicians) makes objective comparison impossible. There remain some recommendations about how best to avoid a poor outcome, although even these have exceptions that are regularly quoted by those with a different view. These recommendations would include: Correct the radiographic anatomy Identify and manage associated injuries Consider reduction of articular steps greater than 1 mm Control oedema and pain at an early stage Consider the ulna in all wrist fractures Be aware of risk factors for redisplacement B osteoporosis B comminution B tenuous stabilization
Conclusion Fractures of the distal radius are common, and their assessment and management are often taken for granted. However, an appreciation of the structure and function of the wrist and the application of sound biomechanical principles allows a reasoned approach to decision-making and can facilitate treatment choices, both operative and non-operative. Articular reconstruction of the radiocarpal
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19 Knirk JL, Jupiter J. Intra-articular fractures of the distal end of the radius in young adults. J Bone Joint Surg Am 1986; 68-A: 657e9. 20 Campbell DA. Open reduction and internal fixation of intra-articular and unstable fractures of the distal radius using the AO distal radius plate. J Hand Surg Br 2000; 25-B: 528e34. 21 Jakob M, Rikli DA, Regazzoni P. Fractures of the distal radius treated by internal fixation and early function. A prospective study of 73 consecutive patients. J Bone Joint Surg Br 2000; 82-B: 340e4. 22 Orbay JL, Fernandez DL. Volar fixation for dorsally displaced fractures of the distal radius: a preliminary report. J Hand Surg Am 2002; 27A: 205e15. 23 Orbay JL, Touhami A. Current concepts in volar fixed-angle of unstable distal radius fractures. Clin Orthop 2006; 445: 58e67. 24 Kreder HJ, Hanel DP, Agel J, McKee M, Schemitsch EH, Trumble TE, et al. Indirect reduction and percutaneous fixation versus open reduction and internal fixation for displaced intra-articular fractures of the distal radius. J Bone Joint Surg Br 2005; 87-B: 829e36. 25 Kapoor H, Agarwal A, Dhaon BK. Displaced intra-articular fractures of distal radius: a comparative evaluation of results following closed reduction, external fixation and open reduction with internal fixation. Injury 2000; 31: 75e9. 26 Seitz WH, Froimson AI, Leb R, Shapiro JD. Augmented external fixation of unstable distal radius fractures. J Hand Surg Am 1991; 16A: 1010e6. 27 Sanders RA, Keppel FL, Waldrop JI. External fixation of distal radial fractures: results and complications. J Hand Surg Am 1991; 16A: 385e91.
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28 Wright TW, Horodyski M, Smith DW. Functional outcome of unstable distal radius fractures: ORIF with a volar fixed angle tine plate versus external fixation. J Hand Surg Am 2005; 30: 289e99. 29 Handoll HHG, Vaghela MV, Madhok R. Percutaneous pinning for treating distal radial fractures in adults. Cochrane Database Syst Rev 2011. Issue 3. Art. No.:CD006080. doi:10.1002/14651858.CD006080. Pub2. 30 Handoll HHG, Huntley JS, Madhok R. Different methods of external fixation for treating distal radial fractures in adults. Cochrane Database Syst Rev 2008. Issue 1. Art. No.:CD006522. doi:10.1002/ 14651858.CD00652.Pub2. 31 Boyer MI, Korcek KJ, Gelberman RH, Gilula LA, Ditsios K, Evanoff BA. Anatomic tilt X-rays of the distal radius: an ex vivo analysis of surgical fixation. J Hand Surg Am 2004; 29: 116e22. 32 Haugstvedt JR, Berger RA, Nakamura T, Neale P, Berglund L, An KN. Relative contributions of the ulnar attachments of the triangular fibrocartilage complex to the dynamic stability of the distal radioulnar joint. J Hand Surg Am 2006; 31: 445e51. 33 Richards RS, Bennett JD, Roth JH, Milne K. Arthroscopic diagnosis of intra-articular soft tissue injuries associated with distal radial fractures. J Hand Surg Am 1997; 22: 772e6. 34 Davidson JS, Brown DJ, Barnes SN, Bruce CE. Simple treatment for torus fractures of the distal radius. J Bone Joint Surg Br 2001; 83B: 1173e5. 35 Cannata G, De Maio F, Mancini F, Ippolito E. Physeal fractures of the distal radius and ulna: long term prognosis. J Orthop Trauma 2003; 17: 172e9.
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(iii) Adult degenerative scoliosis
Epidemiology & demographics Reported prevalence of adult scoliosis ranges from 1 to 10%.2 Such new-onset deformity is observed in more than 30% of elderly patients with no past history of spinal deformity. Degenerative scoliosis is typically diagnosed in patients older than 40 years, with a mean age of 70.5 years. They are lumbar curves measuring >10 with associated distal fractional curves. Although the curves are not associated with structural thoracic curves, compensatory thoracic curves can occur. As in AIS, curve prevalence in ADS is inversely proportional to curve magnitude. The prevalence of 10 , 10e20 and >20 curves is 64, 44, and 24%, respectively. These curves have roughly a 1:1 female/male ratio. An overall increase is seen due to the demographic shift towards an ageing society.4
Anant D Tambe Antony Louis Rex Michael
Abstract In an ageing population adult degenerative scoliosis, a subset of adult scoliosis, is a growing problem. The spinal curves, unlike those of idiopathic scoliosis, are predominantly lumbar. Patients usually complain of axial pain, neurogenic claudication and radicular symptoms. Initial conservative management is indicated. If that fails, surgical treatment may be indicated, which requires careful patient selection, pre-operative assessment and pre-optimization to reduce the incidence of complications. Surgery is aimed at correcting the deformity, achieving adequate decompression, while obtaining solid spinal fusion and restoration of adequate coronal and sagittal balance.
Clinical presentation & natural history Symptoms of degenerative scoliosis are most frequently progressive back pain with radiculopathy and neurogenic claudication.5 Ageing progressively affects all structures of the spinal unit, eventually leading to spondylolisthesis, spinal stenosis and scoliosis. Due to multiple degenerative pathologies, identifying the exact source of pain is difficult. Relationships between scoliotic pattern and patient symptoms are unclear, although speculations on such relationships are frequently made.5e7 Pain at the convexity is caused by fatigue of the paraspinal muscles5e8 or arises from the facet joints. Pain at the concavity of the curve is thought to be caused by destruction of the facet joints8 and degenerative changes in disc spaces.6,7 Radicular pain at the concavity can arise from narrowed foramina5,8 or ruptured discs causing radiculopathy. Dynamic overstretch of a nerve root might also cause radicular pain on the convex side.9 One of the common syndromes is of spinal stenosis. Such symptoms in this group of patients are not relieved by leaning forward, as is seen in those with neurogenic claudication not associated with scoliosis. This distinction is important because the prognosis and treatment of ADS are different from those in patients with degenerative spinal stenosis. Pulmonary compromise with severe thoracic scoliosis (curve >80 ) is well recognized, due to loss of lung volumes and inability to expand the thorax with inspiration. This is a greater problem in patients with idiopathic scoliosis with progression in adult life, but is unusual in patients with degenerative scoliosis and lumbar curves. ADS curves tend to progress 1e6 per year (average 3 per year).10 Factors implicated in curve progression are osteopenia,1,11 curves with Cobb angles >30 , an apical rotation greater than Grade II, a lateral listhesis >6 mm, and an inter-crest line through L-5.10 Patient age and/or sex are not associated with curve progression in ADS.12
Keywords complications; degenerative scoliosis; lumbar curves; posterior instrumentation; sagittal balance
Definitions Scoliosis is a complex three-dimensional rotational deformity affecting the spine in the coronal, sagittal, and axial planes. Treatment paradigms must address all three components. Adult scoliosis, be it Adult Idiopathic Scoliosis (AIS) or Adult Degenerative Scoliosis (ADS) is a spinal deformity in a skeletally mature individual, with a curve measuring >10 measured by the Cobb method.1 AIS arises as progression of infantile or adolescent idiopathic scoliosis, but ADS develops during adulthood due to the degeneration of spinal motion segments2 and is termed degenerative scoliosis or de novo scoliosis. Occasionally the curve is compensatory or neuromuscular. Degenerative scoliosis develops most frequently in the lumbar spine, where degenerative changes are most prevalent, whereas in neuromuscular and idiopathic scoliosis the major curve is usually in the thoracic or thoraco-lumbar spine. Lumbar degenerative scoliosis is a rotational disorder that leads to hypo-lordosis associated with a relatively flexible thoracic compensatory curve of typically less than 30 . Common radiographic findings in this population include degenerative changes (most commonly at L5eS1) and rotary subluxation or lateral translation at L3eL4 and obliquity at L4eL5.3
Anant D Tambe MS(Orth) DNB(Tr & Orth) FRCS(Glas) FRCS(Tr & Orth) MCH Orth (L’Pool) Spinal Fellow, Sheffield Teaching Hospitals & Sheffield Children’s Hospital, Northern General Hospital, Herries Road, Sheffield, UK.
Pathogenesis Degenerative scoliosis is assumed to be caused by asymmetric disc degeneration and facet joint degeneration.5,10,13,14 The onset is marked by disc degeneration.10 This distinguishes degenerative scoliosis from other types of scoliosis, such as adolescent idiopathic scoliosis and scoliosis secondary to neuromuscular disease.
Antony Louis Rex Michael DNB(Tr & Orth) FRCS(Ed) M.Med.Sci(Trauma) FRCS(Tr & Orth) Consultant Orthopaedic Spinal Surgeon, Sheffield Teaching Hospitals & Sheffield Children’s Hospital, Northern General Hospital, Herries Road, Sheffield, UK.
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Vertebral rotation and lateral deviation of the spine are coupled phenomena, with the rotation of vertebral bodies directed into the convexity of the curve.15 It has been shown that in the normal non-scoliotic spine there is a predominant leftsided rotation in the high thoracic vertebrae, and that the midand lower thoracic vertebrae are predominantly rotated to the right.16 This rotational pattern in the normal spine corresponds with the predominance of right-sided thoracic and thoracolumbar curves in idiopathic and neuromuscular scoliosis.16 However, lumbar vertebrae of the normal spine do not show a predominant rotation, but in idiopathic and neuromuscular scoliosis a left-sided compensatory curve is often seen at the lumbar level.16 While in lumbar degenerative scoliosis, the scoliotic curve is lumbar, it tends to show the same predominant direction as the compensatory lumbar curve in idiopathic or neuromuscular scoliosis. The strong relationship between apical level and curve direction does indicate that in degenerative scoliosis the innate curvature of the spine plays a role in the direction of the curve. In idiopathic scoliosis, it is believed that biomechanical factors play a role in the development and progression of the curvature. It is thought that a spine with scoliosis experiences greater loading on the concave side and that this asymmetrical loading leads to asymmetric growth and thus progression of the deformity. Similar processes may play a role in degenerative scoliosis; the greater loads on the concave side inducing degenerative changes resulting in further progression of the scoliosis. Such changes can be diverse, ranging from degenerative changes in the intervertebral discs to spondylolysis or frank spondylolisthesis, rotatory dislocations and destruction of facet joints, depending on the ‘weakest link’. It is recognized that disc degeneration temporarily induces a segmental instability which makes the spinal construct more vulnerable to forces that increase a slight pre-existing rotatory pattern, such as Dorsally Directed Shear Loads (DDSL’s).16 Lumbar vertebrae are more subject to such loads which supports this hypothesis.
Scoliosis Research Society adult deformity classification Primary curve types Single thoracic (ST) Double thoracic (DT) Double major (DM) Triple major (TM) Thoracolumbar (TL) Lumbar “de novo”/idiopathic (L) Primary sagittal plane deformity (SP) Adult spinal deformity modifiers: regional sagittal modifier (include only if outside normal ranges as listed) Proximal thoracic (T2eT5): >þ20 (PT) Main thoracic (T5eT12): >þ50 (MT) Thoracolumbar (T10eL2): >þ20 (TL) Lumbar (T12eS1): 40 (L) Lumbar degenerative modifier (include only if present) Decreased disc height and facet arthropathy based on X-ray: include lowest involved level between L1 and S1 (DDD) Listhesis (rotational, lateral antero, retro) >3 mm: include lowest level between L1 and L5 (LIS) Junctional L5eS1 curve >10 (intersection angle superior endplates L5 and S1) (JCT) Global balance modifier (include only if imbalance present Sagittal C7 plumb >5 cm anterior or posterior to sacral promontory (SB) Coronal C7 plumb >3 cm right or left of CSVL (CB) SRS definition of regions Thoracic: apex T2eT11eT12 disc Thoracolumbar: apex T12eL1 Lumbar: apex L1eL2 disceL4 Criteria for specific major curve types Thoracic curves: (1) curve >40 ; (2) apical vertebral body lateral to C7 plumb line; (3) T1 rib or clavicle angle >10 upper thoracic curves Thoracolumbar and lumbar curves: (1) curve >30 ; (2) apical vertebral body lateral to CSVL Primary sagittal plane deformity: no major coronal curve
Classification of adult degenerative scoliosis17 Most classification systems are for adolescent scoliosis and as yet there is no generally accepted classification system for adult degenerative scoliosis. The Lenke classification is widely accepted for adolescent scoliosis and has addressed all the drawbacks of previous classification systems. Recently described classifications of adult scoliosis offer specific advantages, for example, the simple pathogenesis-based system of Aebi, the strong clinical relevance of the Schwab system, and the richly descriptive Scoliosis Research Society (SRS) system.17 We use the SRS system.
Table 1
Coronal curve classification is based on apex location, and criteria for specific major curve type are defined objectively. To be classified as a sagittal plane deformity, there must be a kyphosis present that meets the criteria under the regional sagittal modifier. The SRS classification also includes three radiographic modifiers. A regional sagittal modifier was added in recognition of the impact that regional kyphosis or hypo-lordosis has on health status and surgical strategies. The sagittal modifier is included only if the curve lies outside of the designated normal range and separate modifiers are listed for each of the four regions of the spine. Because degenerative changes of the lumbar spine are common in adults with scoliosis and because these changes are often the reason for clinical presentation, a lumbar degenerative modifier was added to the classification. This modifier is only
SRS classification system (Table 1) The SRS classification provides a framework for an evidencebased approach to the management of adult scoliosis patients.18 This depends on standing full-length X-rays in the coronal and sagittal planes and is based on curve type and three modifiers as shown in table. Six major coronal curve types e as well as a single sagittal plane deformity that lacks any associated thoracic or lumbar coronal deformities that would meet requirements of a primary deformity e are distinguished.
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included if the patient exhibits disc space narrowing, facet arthropathy, degenerative spondylolisthesis, or rotatory subluxation of 3 mm or more in any plane. The third modifier, based on global balance, describes imbalance in either the coronal or the sagittal plane. For the purposes of this classification, sagittal imbalance was considered significant if the C7 plumb line is 5 cm or more anterior or posterior to the sacral promontory. Coronal imbalance was significant if the C7 plumb line was 3 cm or more to either side of the Centre Sacral Vertical Line (CSVL). The limitation of the SRS classification system is that it does not take into account clinical parameters such as presenting symptoms, age, and co-morbidities including osteoporosis and systemic disease which can affect the management process.
decompression and probably instrumented fusion at the area of decompression. Family history and social history are relevant because depression, nicotine use5,21 and substance abuse are associated with poor outcomes as well as a history of asthma, chronic obstructive pulmonary disease coronary, cerebro-vascular disease, diabetes, nutritional deficiency, depression, and current significant life stressors.5 Therefore, before surgery, patients are counselled to stop all tobacco products and should receive a thorough systematic clinical evaluation. Patients should be examined in their underwear. They should be assessed first standing with hips and knees fully extended to assess overall coronal and sagittal balance by noting trunk shift (relationship of the patient’s head to the pelvis). Any shoulder or pelvic asymmetry should be noted. Forward and lateral bending manoeuvres help assess the curve rigidity, which can be important for prognosis. Leg-length discrepancy and pelvic obliquity are evaluated. When leg length discrepancy is a possible cause of a deformity, use of a shoe lift can be used to reevaluate the patient to see if the curve can be corrected, although such correction is unlikely in stiffer curves. Sacroiliac joints and trochanters are palpated and evaluated for any hip or knee contractures, and the degree of flexibility is noted. As part of a general examination cafe au lait spots, naevi, skin dimpling, and hairy patches which may be hallmarks of an underlying neurogenic abnormality should be sought and a full neurological examination should be performed including all cranial nerves, assessing motor strength, reflexes, sensory modalities, and gait. A vascular examination using Doppler ultrasonography may be necessary. Finally, cardiopulmonary reserve, bone quality, nutritional, and general health status are evaluated to determine fitness for surgery.1 There are additional factors that may need to be considered. Patients with long-standing deformities may have developed hip and/or knee flexion contractures. As hip flexion contracture restricts the patient’s ability to extend the sagittal plumb line posterior to the hips even after correction of their spinal deformity, it may be necessary to address the hip condition before surgical correction of a spinal deformity.
Quantifying the deformity The apical vertebra is the vertebra associated with the greatest segmental angulation at both its rostral (cephalad) and caudal disc interspaces when compared with all other disc interspaces in the curve. Generally it is in the mid-portion of the curve. Conversely, the neutral vertebrae are those with little or no angulation at the rostral and caudal disc spaces of the curve. In general, an instrumentation construct should not terminate at or near an apical vertebra and should extend to a neutral vertebra to balance forces on the deformity.19 Curve magnitude, flexibility, and the apical vertebral translation of the thoracic and lumbar curves should be measured. Typically, a Cobb angle greater than 25 on lateral-bending X-rays defines a structural curve.1 Structural curves are of greater magnitude and less flexible than compensatory curves. Radiographic signs of degenerative disease are categorized, and listhesis (rotary and lateral) noted. Degenerative segments are often associated with stenosis which must be considered in a treatment plan.1,5,20
Clinical assessment The clinical evaluation starts with a full history. In particular a history of idiopathic scoliosis should be sought to exclude the possibility of a degenerative idiopathic deformity. Patients should be asked if they have experienced any changes in body habitus, gait, or fit of their clothes. Particular note should be taken of a rapidly progressing curve because such may be due to an underlying neurological condition. It is very important to ascertain whether the pain is purely axial or is also radicular in nature. Axial pain is more likely associated with the degree of radiographic lateral subluxation and sagittal imbalance, and thus surgical treatment may necessitate inclusion of the lumbar deformity (lateral subluxation) as well as extensive sagittal realignment. Details of the axial pain should include location, radiation, aggravating and alleviating factors, as well as the time course. In particular, nocturnal pain may suggest a neurogenic source such as a spinal cord tumour. It is also important to rule out other sources of axial spinal pain, such as pathological fractures or infection. When assessing radicular pain, it is important to note whether the pain correlates with the concavity and whether the leg pain stems from central or lateral recess (entrance zone, mid-zone, or exit zone) stenosis or both, as the latter may require greater bone
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Radiological investigation Full-length (36-inch) including standing posterioreanterior and lateral X-rays images should be obtained and compared with any previous films to assess curve progression. The Cobb angle and the superior and inferior extent of the measurement should be recorded. These films with bending films are used to define the structural and compensatory curves as well as the overall balance, both coronal and sagittal. If surgery is being considered, flexion/extension and lateral bending films will define curve flexibility and any areas of instability. However, in most cases of adult scoliosis, the curves are rigid without significant movement. Depending on the neurological examination detailed imaging of the neuro-axis by MRI may be indicated. Osteoporosis: there has been some concern that complication rates are slightly higher in patients with osteoporosis and there is also an effect on fusion rates.22,23 Adult scoliosis patients have a high prevalence of osteoporosis24 which can affect surgical
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Sagittal imbalance can be classified into Type I or II.3 Type I includes patients who are globally balanced but in whom a segmental portion of the spine is flat or kyphotic. In contrast, Type II sagittal imbalance describes global and segmental imbalance. When sagittal and coronal imbalance coexist, they divided into Type A or B. With Type A imbalance, the patient’s shoulders and pelvis are tilted in opposite directions. Conversely, with Type B imbalance, both the shoulders and the pelvis tilt in the same direction. Once the latter situation is recognized in a rigid spine, then alternative bone resection techniques can be considered. The centre sacral line is used to assess coronal balance. This is a line that bisects a line passing through both iliac crests and ascends perpendicularly. The vertebrae bisected most closely by this line are known as the ‘stable vertebrae’.
options and significantly impact the operative plan. The National Osteoporosis Foundation has published patient characteristics that may predict poor bone quality, including history of fracture as an adult or fracture in a first-degree relative, white race, advanced age, smoking, low body weight, female sex, dementia, poor health, or fragility.5,24 The degree of bone loss may be inferred from the plain X-rays and computed tomography images. In patients with significant risk factors dual-energy X-ray absorptiometry may be necessary. These studies can be used to tailor the reconstructive techniques to the bone quality of the patient5 as well as being useful to define pedicular sizes and rotation to assist in planning screw placement. Spinal balance (Figure 1) Perhaps the single most important principle in the surgical treatment of adult scoliosis is achieving and maintaining a proper sagittal and coronal balance to orient the spine so that the head is directly above the pelvis. This makes for decreased energy requirements on walking, limits pain and fatigue, improves cosmesis, patient satisfaction and limits complications associated with unresolved (or new) deformities.25 The sagittal vertical axis is determined and defined by a plumb line on a standing lateral X-ray from the middle of the C7 vertebral body. In a patient with a sagittally balanced spine, the plumb line should pass between 2 cm and 4 cm posterior to the ventral S1 vertebra19 or 1 cm posterior to the L5/S1 disc space.25 If this line falls anterior to the S1 vertebra, it is referred to as positive (þ) balance, if posterior, negative () balance. Any spine with a positive value is considered to be out of sagittal balance.
Treatment Adult degenerative scoliosis presents a variety of treatment challenges. Due to the degenerative changes, the curves are more rigid than in adolescent curves and thus require more extensive releases and osteotomies to improve balance. Patients are older with medical co-morbidities and problems like osteoporosis which make surgical fixation difficult. Thus proper patient selection and a rational approach form the cornerstone for successful outcomes in these patients. Non-operative management Initial management is based on similar principles to managing patients with low back pain. Patients should be treated with physical therapy and hydrotherapy and low impact muscle strengthening and endurance exercises. Various methods of pain control can be used, such as epidural steroid injections, nerve root blocks and facet joint injections. Bracing has not been proven to be useful and in fact may be detrimental if used over long periods because of the risk of muscle wasting.1,5 Indications for operative intervention Unlike adolescent idiopathic scoliosis, it is not the deformity, skeletal age or progression, but rather pain and disability that drive treatment. Thus patients whose non-operative pain management has failed should be considered for surgical treatment. Surgical treatment options should be considered when there is correlation between clinical and specific radiographic findings, particularly L-3 and L-4 endplate angulation, lumbar lordosis, thoraco-lumbar kyphosis, and lateral listhesis. Lumbar curves with >30e40 and/or 6 mm of listhesis on presentation should also be considered for operative intervention.1,5 Other considerations to be taken into account are curve progression and progressive neurological deficit, specifically patients whose curves progress more than 10 and/or have an increase in subluxation >3 mm with increasing clinical symptomatology. Principles of surgical management The aim of treatment is correction and stabilization of the deformity. This is achieved firstly by posterior segmental correction using pedicular screws and rods. With modern implant systems and a variety of correction manoeuvres such as apical translation and de-rotation, CotreleDobousset rotation and cantilever techniques, very good correction can be achieved
Figure 1 In a spine with normal sagittal balance the plumb line passes 2e4 cm posterior to the ant superior corner of S1. In the figure on the right the plumb line passes more then 5 cm ant to the sacrum (Positive sagittal Imbalance).
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without the need for anterior releases. It is also important to achieve an adequate decompression of the nerve roots and the central canal (Figures 2 and 3). Once correction has been achieved, decortication and grafting are used to achieve arthrodesis. If the deformity is not corrected it reduces the chances of a fusion and increases the chances of implant failure.5 In particular correction of the deformity and restoration of sagittal balance are important because the loss of lumbar lordosis has been shown to be associated with poor outcomes.25e27 Structural anterior column support provides several benefits such as improved stability, decreased stress on posterior instrumentation, improved fusion rates, better correction of lumbar hypo-kyphosis and imbalance. In addition, it adds indirect decompression via foraminal distraction. It helps decrease pseudarthrosis, especially in smokers, patients with diabetes, and osteopenia. In the latter group, it also helps prevent posterior instrumentation failure by load sharing, especially in obese patients.28 A lumbar interbody fusion [Trans-foraminal Lumbar Interbody Fusion (TLIF), eXtreme Lateral Interbody Fusion (XLIF) or Posterior Lumbar Interbody Fusion (PLIF)] may achieve these goals through a posterior-only approach using specially designed cages (Figures 6 and 7). To further assist in correction of the deformity, the cage may be biased to the concavity of the scoliosis deformity to address the coronal plane. Such techniques avoid the complications of a direct anterior approach.29e31
However, the greatest advantage of anterior interbody fusion is that it permits direct visualization of the anterior intervertebral disc space. As a result, it is generally accepted that the ability to achieve a more complete discectomy and theoretically, a better fusion than with PLIF, TLIF or XLIF28e30 is to be preferred. Many adult deformities are rigid and therefore require combined surgical approaches. ‘Same-day’ or ‘combined’ procedures within a reasonable time period such as less than 12 h may be preferable to ‘staged’ procedures as care must be taken in proceeding with the second stage because the patient can become malnourished with the risk of attendant complications if the interval is too great. Therefore, if a surgical procedure needs to be staged, there should be supplemental nutrition between the stages.5 Fusion and bone-grafting techniques Unfortunately the risk of pseudoarthrosis in adult scoliosis is significantly higher than in the paediatric patients. The rate in adults has been reported in large series of deformity patients after long fusion procedures to be as high as 24%.32 Statistically significant risk factors include: thoraco-lumbar kyphosis hip osteoarthritis thoraco-abdominal rather than para-median approach positive sagittal balance greater than 5 cm age greater than 55 years incomplete sacro-pelvic fixation.32
Figure 2 63 Year old patient with severe back pain and progressive deformity Normal L5/S1 disc on MRI.
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Figure 3 Patient in Figure 2 AP and ateral 6 months post-operatively.
been demonstrated in patients with adult spinal deformity.33 The efficacy of other autograft alternatives has yet to be proven.
Auto-grafting remains the gold standard technique, but attempts to reduce the morbidity associated with iliac crest autograft harvest has led to the development of alternatives, not least when iliac instrumentation is planned. Additionally if local autograft is insufficient for a long fusion, alternatives that have been tried include allograft products, synthetics, ceramics, bone graft extenders, and the bone morphogenic proteins (BMP). The fusion efficacy of one bone morphogenic protein (BMP-2) has
Fixation in osteoporotic bones A specific feature of adult degenerative scoliosis is osteoporosis. Unfortunately, spinal instrumentation with pedicle screw fixation can be less effective in osteoporotic bone.22 Because trabecular bone is predominantly affected by osteoporosis, and the cortical
Figure 4 59 Year old patient with severe back pain and leg pain showing a black disc at L5/S1 on MRI.
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Figure 5 Patient in Figure 4 post op. Posterior only correction with restoration of sagittal balance. Fixation has been extended to Sacrum.
contact of a pedicle screw is limited to the isthmus of the pedicle, a ‘windscreen wiper’ mode of failure typically leads to screw loosening.34 Therefore, fixation strategies for osteoporotic bone are targeted either toward taking advantage of the relatively stronger cortical bone35 or towards augmenting the fixation of a pedicle screw within the existing trabecular bone.23
Techniques to improve the fixation of pedicle screws within osteoporotic trabecular bone have also been developed, including augmenting them with polymethylmethacrylate cement.5 Calcium sulphate paste which has the theoretical advantage of becoming replaced by bone over time has been used.5 Bi-cortical screw fixation which unfortunately increases
Figure 6 68 year old patient with degenerative scoliosis back pain and radicular leg pain.
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Figure 7 Patient in Figure 6 after corrected by anterior only instrumentation by XLIF, achieving indirect foraminal decompression.
focal kyphotic angle is >10 at the proposed proximal fusion level.40 Thus in the presence thoracic curves proximal fusion levels should never stop at a rotatory subluxation and furthermore, the thoracic physiological apex must be avoided. Hence, the fusion should stop well below T10 or well above T5e6. Additionally, fusion at T12 and above should be considered for extension to the pelvis.
the risk of vascular injury and alternative screw designs (conical screws, hydroxyapatite coated screws, and expandable screws) have also been tried. More recently fenestrated screws which allow cement to be injected into them have been trialled as they have a significantly increased pull out strength in cadaveric models.36 Various other methods have been used for treatment of the osteoporotic patient, including sub-laminar wires and pediculolaminar fixation,37 both of which take advantage of cortical bone composition of the posterior spinal lamina. More recently universal clamps which are biomechanically more robust than the sub-laminar wires have been introduced. Medical strategies using newer bone forming drugs like Teraperatide and Strontium have been tried to increase the bone density prior to surgery.38
Extension of fusion to sacrum (Figures 4 and 5) A frequent dilemma in deformity surgery is where to place the caudal end of the fusion. Typically fusions are extended to the sacrum if there is: spondylolisthesis previous L5S1 laminectomy stenosis requiring decompression at L5eS1 severe degeneration an oblique takeoff (>15 ) of L5 to the sacrum with a fractional curve >15 .9 Unfortunately, there is a relatively high rate of pseudoarthrosis (and other complications) after posterior L5eS1 fusion with long constructs in scoliosis patients41,42 and fusions to the sacrum in adult degenerative scoliosis patients were found to require more surgical procedures than those that ended at L5 and had more post-operative complications.41 For these reasons, some authors have advocated avoiding fusion to the sacrum whenever possible.32 However, fusions ending at L5 were associated with a 61% rate of adjacent segment disease, and associated alteration in the patient’s sagittal balance.34 Augmentation of lumbo-sacral fixation in long constructs with anterior column support by inter-body fusion at L5eS1 improves biomechanical stability28 and reduces the risk of lumbo-sacral pseudoarthrosis.43 An anterior structural graft at L5eS1 can also recreate the lordosis, which is typically lost in such patients, and partially restores sagittal balance. It may also diminish stenosis by restoring the intervertebral height. When fusion to
Fusion levels20 As has been said, the aim of surgery is to achieve a solid arthrodesis, stop curve progression and improve the ultimate clinical outcome. One area of difficulty is deciding which levels to include in the construct. Discography and facet joint injections can be used to determine the painful levels. In general, at a minimum, the apex of the deformity is included, particularly if it involves L3 or L4 and includes a lateral or rotary listhesis. There is no general consensus as to the level at which a lumbar construct should terminate rostrally, although one must consider extending a fusion into the thoracic spine and in particular not ending it at the thoraco-lumbar transitional zone. While the ideal is a ‘stable vertebra’ where the end level of the fusion construct should be bisected by the centre sacral line, because of degenerative change, disc space collapse and stiffening in the adult spine, this is not mandatory as it is in the treatment of adolescent or neuromuscular curves. It is recognized that there is a risk of junctional kyphosis proximally if the fusion stops at the apex of a thoraco-lumbar kyphosis.39 Junctional kyphosis is likely to develop when the
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the sacrum is performed, iliac fixation should be considered, particularly if the fusion includes more than three levels.5,32
criteria for Level IV treatment who also have thoracic hyperkyphosis and/or thoracic decompensation. Additionally patients with global or coronal imbalance are candidates for thoracic extension of their fusion and instrumentation. Very often, osteotomies can be particularly useful in this subgroup of patients. Double major thoracic and lumbar curves in which there are two structural curves of approximately equal size (most commonly a right thoracic curve with a left lumbar curve) pose a particular problem. While such patients may present with axial skeletal pain, the typical presentation is one of progression of the deformity manifested as changes in balance, ambulation, and cosmesis. The surgical treatment of a progressive double major curve often requires anterior and posterior procedures. Curve stiffness is related to both patient age and curve magnitude. Flexibility decreases by 10% with every 10-degree increase in coronal deformity beyond 40 and flexibility decreases by 5e 10% with each decade of life.5 While a long, relatively inflexible deformity may require anterior releases to achieve effective reduction and fusion with posterior surgery, the increased ability to manipulate a curve with modern instrumentation through a posterior approach may lessen the need for anterior releases.
LenkeeSilva treatment algorithm (Table 2) Level I treatment: decompression alone: this is usually suitable for patients with neurogenic claudication due to central stenosis who require a limited decompression. Radiographically anterior osteophytes should be present with no more than 2 mm of subluxation and reasonable sagittal/coronal balance. There should be minimal or no back pain and/or deformity, and the curve should be <30 without thoracic hyper-kyphosis and/or imbalance, because decompression alone for stenosis with associated scoliosis can lead to progression of deformity and worsening of symptoms.1 Level II treatment: instrumentation limited to the area of the decompression: this is indicated in patients with the neurogenic claudication and curves <30 , more than 2 mm of subluxation with no local anterior osteophytes requiring extensive decompression. Again, there should be no back pain and/or deformity symptoms or thoracic hyper-kyphosis in a relatively wellbalanced patient.
Treatment level VI : osteotomies: patients whose deformity demonstrates >30% correction on bending radiographs do not require osteotomies as they are considered flexible. Curves that correct <30% are considered stiff and may require osteotomizing. However, many deformities are rigid, and patients are not clinically balanced or they have already undergone fusion. This group of patients may require osteotomies. Osteotomies can aid not only in clinically rebalancing the patient, but also in decreasing the load placed on the instrumentation at the metalbone interface. Rebalancing the spine is of the utmost clinical importance as a significant link has been found between it and clinical outcome.44 The intelligent use of osteotomies begins with the judicious evaluation of both clinical and radiographic coronal and sagittal balance and forms the main component of Level VI treatment. With Type I sagittal imbalance, Smith-Petersen osteotomies are indicated, provided that mobility at the disc space is adequate to permit extension.45 If the disc space is not sufficiently mobile but bone stock is adequate, then anterior releases with
Level III treatment: in addition to the area of decompression, the entire lumbar curve is included in the instrumented fusion: this is indicated when there are symptoms of back pain are associated with the spinal deformity. Typically, these curves are >45 , have >2 mm of subluxation, and lack anterior osteophytes in the operative region, but with reasonable coronal and sagittal balance. The clinical correlation of pain with the location of the curve is very important in selecting the appropriate operative treatment. Level IV treatment: anterior and posterior fusion of the lumbar spine: this would be undertaken for similar indications for level III utilizing techniques such as Posterior Lumbar Interbody Fusion (PLIF), Trans-foraminal Lumbar Interbody Fusion (TLIF), eXtreme Lateral Interbody Fusion (XLIF) or Anterior Lumbar Interbody Fusion (ALIF). Level V treatment: extension of the fusion and instrumentation into the thoracic region: this is indicated in patients satisfying the
Lenke Silva algorithm Symptom
Non Op Management
Level 1
Level 2
Level 3
Level 4
Level 5
Level 6
Neurogenic Claudication/radiculopathy Back Pain Ant Osteophytes Olisthesis Coronal Cobb (<30) Lumbar Kyphosis Global imbalance
minimal minimal þ
þ minimal þ
þ
þ þ þ þ
þ þ þ þ þ
þ þ þ þ þ þ Flexible
þ þ þ þ þ þ Stiff
Abbreviations: ant ¼ anterior; þ ¼ present; ¼ absent. See text for greater detail.
Table 2
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a concomitant morsellized graft can be used. If the bone stock is inadequate, then anterior structural grafts are used. They can also be used for Type II imbalances if Smith-Petersen osteotomies permit the weight-bearing line to fall within 3 cm of the sacrum. An alternative for Type II imbalance is a Pedicle Subtraction Osteotomy (PSO), which is useful if the bone stock is poor and in smokers and diabetic patients because bone-on-bone contact takes place at the time of osteotomy closure and there are high vertebral body fusion rates. Typically, it affords w30 of lordotic correction; hence, it is often suitable for global imbalance correction without the need for anterior releases or structural grafting. Anterior support may be necessary when fusing to the sacrum, but with current techniques, this can easily be achieved via a posterior-only approach. The precise amount of bone resection to achieve a balanced spine is readily calculated using simple trigonometric calculations. Asymmetrical pedicle subtraction osteotomies are often useful in correcting Type A bi-planar deformities. The more radical vertebral column resection technique is often necessary for the rare Type B deformity.1
infarction, pneumonia, paralytic ileus, urinary tract infection, deep venous thrombosis, superior mesenteric artery syndrome, and blindness. Instrumentation related complications are a difficult challenge. The two most common mechanisms of failure are fracture/late screw loosening of rostral instrumentation or late progressive kyphosis at the rostral aspect of the construct. Progressive kyphosis may be minimized by not ending the construct within the curve; longer constructs over the thoracolumbar junction or apex of the kyphosis avoid this problem. Such longer constructs should not be considered overly aggressive, particularly in the osteoporotic spine. However, each patient must be individually evaluated and the specific construct modified to meet the goals of the procedure. Infection rates depend on the approach and the age of the patient. Overall, infection rates in scoliosis surgery are reported between 1% and 2%, but adult patients have a greater infection rate at 3e5%. Infection rates after anterior surgery alone is reported to be approximately 1%.47,48 Despite a low rate of infection, a deep infection can lead to significant sequelae and may require multiple operations to eradicate it. As already described, the risk of pseudoarthrosis increased if the fusion was extended to the sacrum and may require revision surgery if symptomatic.5,47,48 Although major complications can occur, fortunately, neurological injury occurs in less than 1e5% of cases. Significant risk factors for major intra-operative neurological deficits include hyper-kyphosis and combined surgery. Presentation of neurological deficits can be delayed, and paraplegia has been well described occurring several hours after spinal reconstruction surgery. Post-operative hypo-volaemia and mechanical tension on spinal vessels along the concavity of the curve have been implicated as the cause of spinal cord ischaemia leading to delayed postoperative paraplegia. Therefore, it is important to maintain adequate volume and blood pressure in the patients during the postoperative period. Post-operative visual loss is another rare but devastating complication, with an estimated risk of 0.05% and 1%.5,47,48 Risk factors implicated are hypotension, low haematocrit, and coexisting retinal or ocular disease. Unlike delayed post-operative paraplegia that may resolve after adequate volume support, the visual losses were permanent in most patients.
Adjacent segment disease The risk of the development of degenerative changes in adjacent segments must be considered. The pre-operative status of the segment or disc is the best predictor for the development of adjacent segment disease. For the population with adult scoliosis, where some identifiable degenerative disease is nearly universal, this is particularly relevant. Thus care should be taken not to end a fusion adjacent to a severely degenerated disc. It has also been shown that ending a fusion adjacent to a segment with fixed obliquity or subluxation results in adverse results.3,20 Intraoperatively, efforts should also be made to preserve the supraadjacent facet and the interspinous and the supra-spinous ligaments, thus preserving the normal intervertebral ligamentous relationships. In summary, there are several important factors to be considered in the adult scoliosis patient population with poor bone quality. Appropriate balance reduces junctional forces, which diminishes the risk of both instrumentation failure and adjacent vertebral fractures. The surgeon should endeavour to balance the rostral and caudal ends of the construct. A meticulous fusion procedure, augmented with appropriate bone graft or bone graft substitutes, is especially important.
Complications
Conclusion
The results of operative correction of adult deformity have improved significantly with better instrumentation systems, improved anaesthesia and blood salvage. The incidence of complications depends on the approach, level of deformity, age of the patient, and experience of the surgeon.5 For example, there was a 500% increase in major complications between the youngest and eldest patient populations. The risk of complications increases in the older group because of many associated medical co-morbidities including osteopenia. The clinical outcomes appear to outweigh the risks in appropriately selected patients.46 The commonest complications are infection, CSF leaks, implant failures, junctional kyphosis, adjacent disc disease and pseudoarthrosis. Systemic complications include myocardial
Adult degenerative scoliosis is an increasing problem due to an ageing population. It poses very different challenges to those of adolescent scoliosis to spinal surgeons. There is a high risk of complications associated with surgical intervention. In properly selected patients a beneficial outcome can be expected. A
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REFERENCES 1 Silva FE, Lenke LG. Adult degenerative scoliosis: evaluation and management. Neurosurg Focus 2010 Mar; 28: E1. PubMed PMID: 20192655. 2 Grubb SA, Lipscomb HJ, Coonrad RW. Degenerative adult onset scoliosis. Spine 1988; 13: 241e5.
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3 Bridwell KH. Adult spinal deformity revision surgery. In: Heary RF, Albert TJ, eds. Spinal deformity: the essentials. 1st edn. New York: Thieme, 2007; 240e248. 4 Schwab F, Dubey A, Gamez L, et al. Adult scoliosis: prevalence, SF-36, and nutritional parameters in an elderly volunteer population. Spine 2005; 30: 1082e5. 5 Birknes JK, White AP, Albert TJ, Shaffrey CI, Harrop JS. Adult degenerative scoliosis: a review. Neurosurgery 2008 Sep; 63(3 suppl): 94e103. Review. PubMed PMID: 18812938. 6 Ploumis A, Transfledt EE, Denis F. Degenerative lumbar scoliosis associated with spinal stenosis. Spine J 2007; 7: 428e36. 7 Ploumis A, Liu H, Mehbod AA, Transfeldt EE, Winter RB. A correlation of radiographic and functional measurements in adult degenerative scoliosis. Spine (Phila Pa 1976) 2009 Jul 1; 34: 1581e4. PubMed PMID: 19564768. 8 Winter RB, Lonstein JE, Denis F. Pain patterns in adult scoliosis. Orthop Clin North Am 1988; 19: 339e45. 9 De Vries AA, Mullender MG, Pluymakers WJ, Castelein RM, van Royen BJ. Spinal decompensation in degenerative lumbar scoliosis. Eur Spine J 2010 Sep; 19: 1540e4. Epub 2010 Mar 19. PubMed PMID: 20300782; PubMed Central PMCID: PMC2989284. 10 Pritchett JW, Bortel DT. Degenerative symptomatic lumbar scoliosis. Spine 1993; 18: 700e3. 11 Robin GC, Span Y, Steinberg R, Makin M, Menczel J. Scoliosis in the elderly: a follow-up study. Spine 1982; 7: 355e9. 12 Korovessis P, Piperos G, Sidiropoulos P, Dimas A. Adult idiopathic lumbar scoliosis. A formula for prediction of progression and review of the literature. Spine 1994; 19: 1926e32. 13 Aebi M. The adult scoliosis. Eur Spine J 2005 Dec; 14: 925e48. Epub 2005 Nov 18. Review. PubMed PMID: 16328223. 14 Benoist M. Natural history of the aging spine. Eur Spine J 2003; 12(suppl 2): S86e9. 15 White III AA, Panjabi MM. Practical biomechanics of scoliosis. Clinical biomechanics of the spine. Lippencott, 1979. 16 Kouwenhoven JW, Castelein RM. The pathogenesis of adolescent idiopathic scoliosis: review of the literature. Spine 2008; 33: 2898e908. 17 Smith JS, Shaffrey CI, Kuntz 4th C, Mummaneni PV. Classification systems for adolescent and adult scoliosis. Neurosurgery 2008 Sep; 63(3 suppl): 16e24. Review. PubMed PMID: 18812919. 18 Lowe T, Beven SH, Schwab FJ. The SRS classification for adult spinal deformity: building on the King/Moe and Lenke classification system. Spine 2006; 31: 2104e14. 19 Benzel EC. Deformity prevention and correction: complex clinical strategies. In: Biomechanics of spine stabilization. New York: American Association of Neurological Surgeons, 2001; 375e410. 20 Bridwell KH. Selection of instrumentation and fusion levels for scoliosis: where to start and where to stop. Invited submission from the Joint Section Meeting on Disorders of the Spine and Peripheral Nerves, March 2004. J Neurosurg Spine 2004; 1: 1e8. 21 Warner MA, Offord KP, Warner ME, et al. Role of preoperative cessation of smoking and other factors in postoperative pulmonary complications: a blinded prospective study of coronary artery bypass patients. Mayo Clin Proc 1989; 64: 609e16. 22 Halvorson TL, Kelley LA, Thomas KA, Whitecloud 3rd TS, Cook SD. Effects of bone mineral density on pedicle screw fixation. Spine 1994; 19: 2415e20. 23 Tan JS, Kwon BK, Dvorak MF, Fisher CG, Oxland TR. Pedicle screw motion in the osteoporotic spine after augmentation with laminar
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hooks, sublaminar wires, or calcium phosphate cement: a comparative analysis. Spine 2004; 29: 1723e30. Lane JM, Riley EH, Wirganowicz PZ. Osteoporosis: diagnosis and treatment. Instr Course Lect 1997; 46: 445e58. Jackson RP, Simmons EH, Stripinis D. Coronal and sagittal plane spinal deformities correlating with back pain and pulmonary function in adult idiopathic scoliosis. Spine 1989; 14: 1391e7. Glassman SD, Berven S, Bridwell K, Horton W, Dimar JR. Correlation of radiographic parameters and clinical symptoms in adult scoliosis. Spine 2005; 30: 682e8. Schwab FJ, Smith VA, Biserni M, Gamez L, Farcy JP, Pagala M. Adult scoliosis: a quantitative radiographic and clinical analysis. Spine 2002; 27: 387e92. Polly Jr DW, Klemme WR, Cunningham BW, Burnette JB, Haggerty CJ, Oda I. The biomechanical significance of anterior column support in a simulated single-level spinal fusion. J Spinal Disord 2000; 13: 58e62. Crandall DG, Revella J. Transforaminal lumbar interbody fusion versus anterior lumbar interbody fusion as an adjunct to posterior instrumented correction of degenerative lumbar scoliosis: three year clinical and radiographic outcomes. Spine (Phila Pa 1976) 2009 Sep 15; 34: 2126e33. PubMed PMID: 19752698. Hsieh PC, Koski TR, O’Shaughnessy BA, et al. Anterior lumbar interbody fusion in comparison with transforaminal lumbar interbody fusion: implications for the restoration of foraminal height, local disc angle, lumbar lordosis, and sagittal balance. J Neurosurg Spine 2007; 7: 379e86. Robert Isaacs E, Hyde Jonathan, Allan Goodrich J, Rodgers William Blake, Phillips Frank M. A prospective, nonrandomized, multicenter evaluation of extreme lateral interbody fusion for the treatment of adult degenerative scoliosis. Perioperative outcomes and complications. Spine 2010; 35(26 suppl): S322e30. Lippincott Williams & Wilkins. Kim YJ, Bridwell KH, Lenke LG, Rhim S, Cheh G. Pseudarthrosis in long adult spinal deformity instrumentation and fusion to the sacrum: prevalence and risk factor analysis of 144 cases. Spine 2006; 31: 2329e36. Carragee EJ, Hurwitz EL, Weiner BK. A critical review of recombinant human bone morphogenetic protein-2 trials in spinal surgery: emerging safety concerns and lessons learned. Spine June 2011; 11: 471e91. Law M, Tencer AF, Anderson PA. Caudo-cephalad loading of pedicle screws: mechanisms of loosening and methods of augmentation. Spine 1993; 18: 2438e43. Coe JD, Warden KE, Herzig MA, McAfee PC. Influence of bone mineral density on the fixation of thoracolumbar implants. A comparative study of transpedicular screws, laminar hooks, and spinous process wires. Spine 1990; 15: 902e7. Chen LH, Tai CL, Lee DM, et al. Pullout strength of pedicle screws with cement augmentation in severe osteoporosis: a comparative study between cannulated screws with cement injection and solid screws with cement prefilling. BMC Musculoskelet Disord 2011; 12: 33. Hilibrand AS, Moore DC, Graziano GP. The role of pediculolaminar fixation in compromised pedicle bone. Spine 1996; 21: 445e51. Gehrig Laura, Lane Joseph, O’Connor Mary I. Osteoporosis: management and treatment strategies for orthopaedic surgeons. Medical strategies in osteoporosis. Selected instructional course lecture June 01, 2008; vol. 90. Shufflebarger H, Suk SI, Mardjetko S. Debate: determining the upper instrumented vertebra in the management of adult degenerative
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45 La Marca Frank, Brumblay H. Smith-Petersen osteotomy in thoracolumbar deformity surgery. Neurosurgery 2008; 63: A163e70. doi: 10.1227/01.NEU.0000320428.67620.4F. 46 Albert TJ, Purtill J, Mesa J, McIntosh T, Balderston RA. Health outcome assessment before and after adult deformity surgery. A prospective study. Spine 1995; 20: 2002e5. 47 Cho SK, Bridwell KH, Lenke LG, et al. Major complications in revision adult deformity surgery: risk factors and clinical outcomes with twoto seven-year follow-up. Spine (Phila Pa 1976) 2011 May 14 [Epub ahead of print] PubMed PMID: 21587110. 48 Sansur CA, Smith JS, Coe JD, et al. Scoliosis research society morbidity and mortality of adult scoliosis surgery. Spine (Phila Pa 1976) 2011 Apr 20; 36: E593e7. PubMed PMID: 21325989.
scoliosis: stopping at T10 versus L1. Spine (Phila Pa 1976) 2006 Sep 1; 31(19 suppl): S185e94. PubMed PMID: 16946637. Yang SH, Chen PQ. Proximal kyphosis after short posterior fusion for thoracolumbar scoliosis. Clin Orthop Relat Res 2003; 411: 152e8. Kostuik JP, Hall BB. Spinal fusions to the sacrum in adults with scoliosis. Spine 1983; 8: 489e500. Bridwell KH, Edwards 2nd CC, Lenke LG. The pros and cons to saving the L5-S1 motion segment in a long scoliosis fusion construct. Spine 2003; 28: S234e42. Kuklo TR, Bridwell KH, Lewis SJ, et al. Minimum 2-year analysis of sacropelvic fixation and L5-S1 fusion using S1 and iliac screws. Spine 2001; 26: 1976e83. Ahn UM, Ahn NU, Buchowski JM, et al. Functional outcome and radiographic correction after spinal osteotomy. Spine 2002; 27: 1303e11.
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(iv) Wrist arthroscopy
joint release (arthrolysis), synovectomy, ganglia resection, midcarpal fusion ("four-corner fusion"), and many more.
Javier Ferreira Villanova
Basic setup
Juan Gonzalez Del Pino
In general, a 2.4 or 2.7 mm 30 angled, short-barrel (50 to 60 mm) scope with a camera is used. There exist a wide variety of traction techniques and an extensive supply of traction devices that may be used to provide joint distraction. In most cases 10 lbs of traction is necessary for an adequate intra-articular visualization. Traction towers provide not only distraction but also the ability to place the wrist in various degrees of flexion, extension and radial and ulnar deviation. The majority of surgeons perform wrist arthroscopy with the patient in a supine position on the operating table, with the upper extremity secured to the arm table (Figure 1). Adequate fluid distension is provided by a continuous inflowoutflow system but one of the main complications is fluid extravasation and the risk of compartment syndrome, if it is to be used for a substantial amount of time. Some surgeons recommend a dry technique without the need of fluid irrigation5 and by combining sequential washout and aspiration this risk is reduced. The most commonly used technique is a gravitypowered irrigation system in which the height of the bags of fluid correlates with intra-articular pressure and the degree of joint distension.5 Useful arthroscopic equipment includes a joint probe, grasping forceps, basket forceps and power equipment (burrs and shavers). Small arthroscopic knives are helpful for TFCC resection and release of joint adhesions.
Abstract Wrist arthroscopy is nowadays a commonly used procedure employed in the diagnosis and treatment of traumatic pathologies, such as triangular fibrocartilage injuries, distal radius fractures, malunions and scaphoid fractures, as well as degenerative conditions such as scapholunate €ck’s disease and dorsal wrist ganglia advanced collapse, wrist, Kienbo cysts. Several procedures have recently been undertaken arthroscopically, such as radial styloidectomy, distal ulnar excision (“wafer procedure”), and proximal row carpectomy. Wrist arthroscopy has become the “gold standard” for the diagnosis of certain wrist injuries such as scapholunate instability. Compared to open techniques, arthroscopic procedures improve the postoperative management in terms of pain and early movement thus allowing an earlier return to work and resumption of daily living activities.
Keywords arthroscopy; ligaments; triangular fibrocartilage; wrist
Introduction
Anatomy & portals
Arthroscopy of the wrist has undergone many modifications and improvements since it was first described by Cheng in 1979.1 It has evolved from being a diagnostic modality to become a valuable and effective therapeutic tool. Arthroscopy has revolutionized the diagnosis and treatment of some articular injuries such as scapholunate (SLIL), lunotriquetral (LTIL) interosseous ligament injuries and triangular fibrocartilage (TFCC) tears.2,3 Arthroscopy provides the capability of examining directly all the intra-articular structures involved. Furthermore, wrist arthroscopy is a useful adjunctive tool in the reduction of intraarticular distal radius fractures and the assessment of concomitant ligament lesions. The advent of new portals e both dorsal and volar e is allowing the surgeon to approach the wrist from, virtually, any perspective, giving rise to the “box concept”.4 The staging of degenerative conditions has been facilitated through the use of the arthroscope, leading to new classifications and therapeutic approaches. Innovative surgeons have continued developing techniques such as proximal row carpectomy (PRC),
The site of wrist arthroscopy portals is critical for an adequate arthroscopic view. The approach should be done through a careful skin incision, followed by controlled penetration of to the capsule with a blunt trochar or a haemostat. In order to achieve a full wrist examination, it is quite important to follow a systematic procedure. It is mandatory to palpate all the articulations and joints to rule out either cartilage or ligament injuries (Figure 3). Radiocarpal dorsal portals The standard portals for wrist arthroscopy are mostly dorsal. Those dorsal portals that allow access to the radiocarpal joint
Javier Ferreira Villanova MD Consultant Orthopaedic Surgeon, Upper Extremity Surgery Unit, Orthpaedic Surgery Department, Guadalajara University Hospital. Guadalajara. Spain and Hand Institute, Rosario Hospital, Madrid, Spain. lez Del Pino MD PHD Consultant Orthopaedic Surgeon, Unit of Juan Gonza Hand and Wrist Surgery, Department of Orthopaedic Surgery, Santa Cristina University Hospital Madrid, Spain and Hand Institute, Rosario Hospital, Madrid, Spain.
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Figure 1 Basic operation room set up for a wrist arthroscopy.
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Midcarpal portals Four portals have been shown to be useful for a full view of the midcarpal space.6 The most common portal used for midcarpal arthroscopy is the radial midcarpal (MCR). This portal is located 1 cm distal to the 3-4 radiocarpal portal and in line with the radial margin of the third metacarpal. Through this portal the joint between the capitate and the concave surface of the scaphoid and the scapholunate, lunatotriquetral and capitohamate joints can be seen. The second most useful portal is the ulnar midcarpal portal (MCU), which is located on the midaxial line of the fourth metacarpal and enters the joint at the four-corner intersection between the lunate, triquetrum, hamate, and capitate. There are also two accessory portals. One of them is placed on the radial side of the midcarpal space, entering the scaphotrapeziotrapezoid (STT) joint. This portal is located just to the ulnar side of the EPL tendon at the level of the articular surface of the distal scaphoid. We must take care to avoid injury to the small branches of the radial nerve while placing this portal. The other accessory portal is at the ulnar aspect of the wrist and enters the triquetrohamate (TH) joint, and it is located just ulnar to the extensor carpi ulnaris (ECU) tendon. This is an excellent portal for an inflow or outflow cannula, and can also be used as a portal for a probe or another instrument to access the TH joint.
Figure 2 Dorsal extensor compartments of the wrist. Dorsal portals are located and named according to them.
are named in relation to their position with the dorsal extensor compartments (Figure 2). There are five main dorsal portals: 12, 3-4, 4-5, 6R and 6U. Normally wrist arthroscopy begins at the 3-4 portal, as it gives an excellent view of the volar aspect of the whole wrist. The portal is placed in the “soft spot” located just distal to the Lister’s tubercle, between the extensor pollicis longus (EPL) and the extensor digitorum communis (EDC) tendons. The rest of the radiocarpal portals are developed under direct vision using a 22-gauge needle to first establish a correct placement.
Figure 3 1) Scope inside the 3-4 portal. We can see the volar aspect of the radiocarpal joint, starting with the extrinsic volar ligaments, the radioscaphocapitate and the long radiolunate ligaments. 2) From the 3-4 portal the ulnar structures such as the TFCC (Triangular Fibrocartilage Complex) an be examined. 3) Midcarpal view from the midcarpal radial portal. A Type 2 lunate can be appreciated. 4) Radiocarpal vision from the 6R portal. The dorsal capsule as well as the dorsal aspect of the radius and carpus can be addressed through that portal; RSC: Radioscaphocapitate ligament. LRL: Long radiolunate ligament. TFC: Triangular fibrocartilage.
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Atzei’s TFCC complex peripheral tears classification. This new classification takes into consideration the instability of the DRUJ as well as the involvement of the proximal or foveal attachment of the triangular fibrocartilage, with therapeutic indications Class
DRUJ instability
Affected TFCC part
TFCC healing
DRUJ cartilage
Treatment
1 2 3 4 5
None/slight Mild/severe Mild/severe Severe Mild/severe
Distal Distal þ proximal Proximal Proximal e
Good Good Good Poor e
Good Good Good Good Poor
Suture Foveal reattachment Foveal reattachment Reconstruction Salvage
Atzei A, Rizzo A, Luchetti R, Fairplay T. Arthroscopic foveal repair of triangular fibrocartilage complex peripheral lesion with distal radioulnar joint instability. Tech Hand Upper Extrem Surg 2008; 12: 226e35.
Table 1
Radiocarpal volar portals The reason for approaches to the wrist from the dorsal aspect arose from the relative lack of neurovascular structures, as well as the familiarity of most surgeons with dorsal approaches to the radiocarpal joint. However, there are still some risks, especially during the learning curve.7 Volar portals have been recently
Midcarpal arthroscopy allows the visualization and palpation of the midcarpal structures. The STT joint is a common location for development of chondral lesions and or degenerative osteoarthritis. The proximal pole of the hamate is another common location for similar lesions. All those lesions can be addressed and treated arthroscopically.
Figure 4 TFCC (Triangular Fibrocartilage Complex) suture. Top left: Suture retriever (Micro SutureLassoTM Arthrex Inc. Naples. FL). Top right: The second end is retrieved through the same portal. Bottom left: Suture knotting. Bottom right: TFCC tension can be tested through the 6R portal.
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studied and popularized by Slutsky.8 There are five main/ principal volar portals: volar radial (VR), volar ulnar (VU), volar radial midcarpal (VRM), volar ulnar midcarpal (VUM) and the volar distal radioulnar joint (DRUJ).9
Indications Post-traumatic lesions of the wrist, such as TFCC tears, interosseous ligament lesions and fractures of the distal radius or the carpus still remain the main indications for a diagnostic or therapeutic arthroscopy. Ulnocarpal disorders Triangular fibrocartilage complex: one of the most common indications for wrist arthroscopy is the diagnosis and treatment of TFCC derangements when non-operative treatment has been unsuccessful. The treatment of choice is either a debridement or a repair, Studies concerning TFCC vascularity, have shown that both the central and radial aspects of the TFCC are largely avascular. We know that DRUJ instability is the most functionally disabling condition that can result from injury to the TFCC. The prime stabilizers of the DRUJ are the dorsal and palmar radioulnar ligaments and the triangular fibrocartilage. The fovea of the ulna is the functional and anatomic origin of the radioulnar ligaments. The term “meniscus homologue” has been used to denote the ulnar sling or leash of tissue that sweeps distally from the surface of the fibrocartilage disk to attach at the articular margin of either the triquetrum or the LTIL. The ECU sub-sheath and the volar ulnocarpal ligaments do not appear to contribute significantly to the DRUJ stability. Wrist arthroscopy has become the gold standard for the diagnosis and staging of TFCC lesions, since triple-injection arthrography and magnetic resonance imaging (MRI) are not entirely satisfactory. According to Palmer’s classification,10 there are four types of acute TFCC lesions. This classification system remains useful, but it does not clarify the most critical issue: the presence or absence of DRUJ instability. In particular, the term “class 1B injury” is now being used to describe two distinct entities: a lesion that is fully stable at the DRUJ (i.e., central fibrocartilage disc separation from the dorsal wrist capsule) and a lesion that produces DRUJ instability (i.e., radioulnar ligament avulsion from the ulnar fovea). A great confusion has been generated in both the evaluation and management of class 1B injuries. The critical distinction is in differentiating injuries that produce instability of the distal radioulnar joint from those that do not. Atzei and coworkers had developed a new classification attending to this important issue (Table 1). Based on the arthroscopic findings, five classes of TFCC peripheral tears are recognized, and guidelines for specific treatment can be considered.11 Palmer class 1A lesions in patients with neutral or negative variance are routinely debrided, since they yield excellent to good results, with no requirement for further surgery. The class 1A lesion is best approached from the dorsal 3-4 portal. Debridement of the disk is performed via the 6R portal. Resection is continued until a stable and smooth residual rim remains. Up to 80% of the substance can be resected without creating a secondary instability. The Palmer class 1B lesion involves injury to the ulnar attachment of the TFCC, either by ligament avulsion from the fovea or due to a fracture through the base of the ulnar styloid. Both subtypes result in DRUJ instability. Just because the damage
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Figure 5 Arthroscopic “wafer” resection. Top: TFCC Type 2C tear. Middle: Tear debridement using a basket forceps. Bottom: Final result after 3mmresection of the ulna head.
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is located in a well vascularized portion of the TFCC, and therefore the healing process can be promoted by suturing these lesions, arthroscopic repair is recommended. The main purpose of such techniques is to suture the torn TFCC to the dorsal ulnocarpal joint capsule and the ECU tendon sub-sheath. Inside-out, outside-in or all-inside techniques have been described as useful to restore TFCC tautness (Figure 4). However these techniques do not address DRUJ instability, and therefore they cannot be a treatment choice in the case of true 1B lesions. When a class 1B is suspected, we must assess the TFCC tension by the “trampoline test” and the hook test. The last one seems to be the best way to check the foveal attachment of the TFCC. Therefore, a DRUJ arthroscopy is needed when a hook test is positive. Well-preserved articular cartilage is mandatory for ligament repair or reconstruction of the DRUJ. Lately, some authors have recommended foveal reattachment of this type of lesions by means of transosseous implants. Promising results have been reported.11,12 There is still controversy regarding the management of class 1D lesions, which can be treated either by debridement or repair. We suggest that those tears that involve the dorsal radioulnar ligament, the volar radioulnar ligament or both, compromising DRUJ stability, should be repaired.
pronation and supination is essential during the entire procedure (Figure 5). An LTIL instability or ulnocarpal ligament rupture or laxity in the presence of an ulna abutment syndrome will not respond to an arthroscopic ulnar shortening (wafer procedure). This is due to the fact that arthroscopic ulna shortening does not address the LTIL or ulnocarpal instability. In order to minimize intra-articular scar formation, the arthroscopic wafer procedure requires an early postoperative mobilization e active and passive range of motion exercises. At about 4 months patients are expected to be pain-free. Ligament injuries Scapholunate ligament injuries: scapholunate interosseous ligament injuries are one of the most common causes of mechanical wrist pain. Despite the increase in knowledge about carpal injuries and improvements in radiological evaluation, the diagnosis of a SLIL tear may be difficult or missed. Arthroscopy has become the gold standard for diagnosis of SLIL injuries, allowing direct vision of both intrinsic and extrinsic ligaments. The articular cartilage state can be checked under static condition as well as during the dynamic mode. We believe that all suspected injuries of the SLIL should undergo arthroscopy. Scapholunate instability without radiocarpal arthritis has been classified into pre-dynamic, dynamic, and static.15 Nowadays there is a wide variety of arthroscopic classifications of this instability. Geissler and co-workers have proposed one which is the most widely used arthroscopic classification.16 Depending on the findings at the radiocarpal and midcarpal arthroscopy, it provides four degrees of injury (Table 2). Many of the SLIL injuries can be managed arthroscopically. Partial SLIL tears of the membranous portion of the ligament, without evidence of instability e pre-dynamic stage e can be addressed by means of debridement of the damaged tissue using a basket forceps or a radiofrequency probe. It seems that instability is not increased by the debridement unless the dorsal and anterior portions of the ligament complex are removed. In those cases where we notice a dynamic dorsal radiocarpal impingement, a dorsal rim milling of the distal radius using a 2.9 burr is recommended (Figure 6). Although the natural history of these lesions is not well known, a dorsal radiocarpal impingement
Ulnocarpal abutment: the ulnocarpal abutment syndrome refers to a painful overload of the ulnocarpal joint. Based on its patho-anatomy, this condition has been classified by Palmer et al. as a class 2 injury.10 Patients presenting with a symptomatic TFCC tear in combination with an ulnar zero or ulnar plus variance are unlikely to respond to a simple debridement of the TFCC.13 Because of the efficacy of the open wafer distal ulna resection as a treatment for ulnar impaction syndrome, several authors have communicated good results with an arthroscopic wafer procedure for ulnocarpal abutment.14 Wafer resection is performed through the 3-4 and 6R portals. The central disc is excised using a basket forceps or a radiofrequency probe, it being mandatory that the dorsal and volar radioulnar ligaments are preserved. Once the ulnar head is visualized, a shaver is used to remove the remaining cartilage from the ulnar head. Afterwards a 2.9 mm burr is advanced through the 6R portal and a 3 mm bony resection is effected. Care must be taken not to affect the sigmoid notch. In order to ensure a complete resection, full
Geissler’s interosseous ligament injury classification Grade
Radiocarpal view
Midcarpal view
Carpal bones gap
I
Attenuation/haemorrhage of the interosseous ligament Attenuation/haemorrhage of the interosseous ligament Incongruence/step off of carpal alignment Incongruence/step off of carpal alignment
No incongruence/step off
None
Incongruence/step off of carpal alignment
Less than the width of the probe
Incongruence/step off of carpal alignment Incongruence/step off of carpal alignment
Probe passes between the carpal bones 2.7 mm arthroscope passes between the carpal bones
II III IV
Geissler WB, Freeland AE, Savoie FH, et al. Carpal Instability Associated with Intra-articular Distal Radius Fractures. Proceedings, American Academy Orthopedic Surgeons Annual Meeting, San Francisco, 1993.
Table 2
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Figure 6 Dorsal radiocarpal impingement. 1) From the 6R portal a ganglion on the dorsal aspect of the scapholunate interval is seen. Fraying of the central portion of the scapholunate ligament is also noticed. 2) Resection of the dorsal ganglion. 3) Debridement of the dorsal lip of the radius. 4) Final appearance.
could worsen the SLIL injury, causing a complete tear, and may contribute to a chronic scapholunate instability condition. In cases where instability is seen (dynamic stage), debridement alone is not sufficient. There is a current controversy regarding the best treatment for these injuries. Some studies are reporting good results with arthroscopic debridement and thermal shrinkage.17,18 Although heat can shrink some tissues, postoperative protection is required during the first few months to maintain the tension while the tissue heals and regains normal function. The critical safe temperature range for achieving thermal shrinkage of tissue without permanent, irreparable damage is believed to be 65e75 C. When faced with a reducible static scapholunate instability, we recommend an arthroscopic reduction of the scaphoid-lunate (ARASL) articulation, that has been described by Hausman et al.19 A compression headless cannulated screw (HCS e Headless Cannulated Screw e Synthes GmbHÒ, Oberdorf) will provide a safe and solid construct, allowing permanent reduction of the scapholunate gap (Figure 7). A more rapid and aggressive postoperative rehabilitation programme is advocated. Wrist fractures Persistent displacement of the articular surface after an intraarticular fracture of the distal radius may predispose to the development of early post-traumatic osteoarthritis. Achieving no more than 1 mm of articular step-off has been recommended as
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Figure 7 Midcarpal view of a 3.0mm headless cannulated screw (HCS -Headless Cannulated Screw-. Synthes GmbHÒ, Oberdorf) across the scapholunate interval during an ARASL (Arthroscopic Reduction Association Scaphoid Lunate) procedure.
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Figure 8 Left: X-Ray AP view of an apparently 2-fragment distal radius fracture. Right: When the fracture is scoped, a 4-fragment fracture is clearly seen. Fracture lines are located at the scaphoid fossa, lunate fossa and dorsal radius; SF: Scaphoid fossa fragment. LF: Lunate fossa fragment. DR: Dorsoradial fragment.
Other indications
the treatment goal. On the other hand, no single technique of intra-operative radiographic imaging has been shown to allow for a reliable measurement of the anatomic fracture reduction (Figure 8). An arthroscopic approach to these problems can be used to cleanse the joint of blood and debris, and to identify for repair the associated ligamentous injuries. Concomitant carpal lesions are reported with an incidence of 25e75% of distal radial fractures, and should be included in the treatment algorithm, especially in young patients. Arthroscopy can also assess minimal articular step-off or gapping after the reduction and stabilization of the fracture. A few studies have suggested that arthroscopic monitoring of the articular alignment has been found superior to an image intensifier view alone.20 Arthroscopic reduction is less invasive than open reduction in managing articular displaced fragments of the articular surface of the distal radius. Open visualization of the articular congruity is advisable only through a dorsal exposure. Complications of wrist fractures such as joint capsule contracture and secondary wrist stiffness can be successfully managed by arthroscopic release. The procedure includes excision of scar tissue on the dorsal and volar aspect of the radiocarpal joint, reducing articular steps and TFCC debridement.21
Ganglion excision: it is well known that dorsal wrist ganglia, the most common tumour-like condition about the wrist, can be treated successfully by arthroscopy, with acceptable recurrence rates (0e20%). Good aesthetic and functional outcomes are advantages of the arthroscopy approach compared to the complications sometimes encountered with open surgery. We use the technique popularized by Osterman and Raphael.22 Because the ganglion is normally located on the radial side of the wrist, the arthroscopic excision is performed under dorsal vision, with a conventional 2.4 mm arthroscope in the 6R portal. The stalk of the ganglion is visualized better from the ulnar side. We use a 2.5 mm shaver introduced inside the ganglion across the 3-4 or the MCR portal. It is also important to perform a dorsal synovectomy, as well as a dorsal capsulotomy to prevent recurrences. Postoperative care includes early active wrist motion, avoiding strenuous work and weight-lifting. Other disorders: as occurs in other joints, impingement of articular surfaces can lead to degenerative changes of these articulations. Some of them have already been explained (i.e., ulnocarpal abutment and dorsal radiocarpal impingement). One
Figure 9 Hamatolunate impingement. Left: Proximal pole chondromalacia. Right: Proximal pole resection.
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such subset of patients includes those with arthritic changes of the proximal pole of the hamate. Viegas et al. found a statistically higher incidence of cartilage erosion with exposed subchondral bone on the proximal hamate in those wrists with a hamateelunate articulation than in those without this anatomical pattern.23 In full ulnar deviation of the wrist, the hamate and lunate impinge at this level. An increased prevalence of tears of the LTIL in patients with proximal hamate osteoarthritis has been noticed. Harley et al. proposed the acronym HALT (hamate arthrosis lunotriquetral ligament tear) wrist to describe this clinical condition.24 A 2.4 mm resection of the proximal pole of the hamate is performed to fully unload the hamateelunate articulation while leaving the loads across the triquetralehamate unchanged (Figure 9). Ulnar styloid impaction syndrome, first described by Topper, is a common cause of ulnar-sided wrist pain, due to the contact between a long ulnar styloid and the triquetrum.25 Initially it was managed with an open excision of the distal ulnar styloid, but arthroscopic procedures have been developed.26 Arthroscopy gives the chance to explore the rest of the wrist, especially the lunotriquetral joint and the ULL and UTL, as well as to perform styloidectomy under direct vision, without harming neighbouring structures (Figure 10).
Finally, many other procedures have been advocated and reported about the benefits of arthroscopy, such as: arthroscopic partial wrist fusion (STT fusion, four-corner fusion) and proximal row carpectomy. These procedures are successfully addressed in expert hands, but still are yet to become safe and reproducible procedures.
Complications Complications related to arthroscopy are similar to those at other joints. They are uncommon, with authors reporting rates of approximately 2%, and are clearly related to the surgeon’s experience and the procedure performed.29 Most complications can be managed by non-operative treatment. Care must be taken with creation of portal sites because of possible injury with the extensor tendons, radial artery, and branches of the radial and ulna nerves. The extensor pollicis longus is the tendon most at risk during wrist arthroscopy. A good wrist anatomy knowledge and meticulous portal dissection significantly reduce the number of postoperative complications. Thermal ablation can produce serious complications such as tendon ruptures and full thickness burns.30 Burns can also occur in the volar side of the forearm due
€ck’s disease: wrist arthroscopy has become a valuable Kienbo €ck’s disease. assessment and a primary treatment tool for Kienbo It allows identification of the nonfunctional joints and tailoring of the surgical reconstructions depending on the anatomic findings. Bain et al. developed an arthroscopic classification system to €ck’s disease.27 This new classification pays attenassess Kienbo tion to the articular damage at the radiocarpal and midcarpal joints, establishing the treatment according to the number and location of the affected joints. Menth-Chiari et al. have reported good results with the use of arthroscopic debridement, especially in terms of pain relief and range of motion.28
Figure 10 Arthroscopic stiloidectomy: Debridement of the ulnar styloid through the 6R portal; S: Ulnar styloid. ECU: Extensor carpi ulnaris.
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Figure 11 Skin burn of the forearm due to heat transmission across the traction device.
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11 Atzei A, Rizzo A, Luchetti R, Fairplay T. arthroscopic foveal repair of triangular fibrocartilage complex peripheral lesion with distal radioulnar joint instability. Tech Hand Upper Extrem Surg 2008; 12: 226e35. 12 Iwasaki N, Minami A. Arthroscopically assisted reattachment of avulsed triangular fibrocartilage complex to the fovea of the ulnar head. J Hand Surg [Am] 2009; 34: 1323e6. 13 Ishikawa J, Suenaga N, Kasashima T. Clinical results of treatment of triangular fibrocartilage complex tears by arthroscopic debridement. J Hand Surg [Am] 1996; 21: 406e11. 14 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: 1047e452. 15 Watson H, Ottoni L, Pitts EC, Handal AG. Rotary subluxation of the scaphoid: A spectrum of instability. J Hand Surg [Br] 1993; 18: 62e4. 16 Geissler WB, Freeland AE, Savoie FH, et al. Carpal instability associated with intra-articular distal radius fractures. San Francisco: Proc AAOS, 1993. 17 Darlis NA, Weiser RW, Sotereanos DG. Partial scapholunate ligament injuries treated with arthroscopic debridement and thermal shrinkage. J Hand Surg [Am] 2005; 30: 908e14. 18 Hirsh L, Sodha S, Bozentka D, et al. Arthroscopic electrothermal collagen shrinkage for symptomatic laxity of the scapholunate interosseous ligament. J Hand Surg [Br] 2005; 30: 643e7. 19 Hausman MR. Arthroscopic RASL. In: Slutsky D, Nagle D, eds. Techniques in wrist and hand arthroscopy. Philadelphia: Churchill Livingstone, 2007; 79e85. 20 Edwards II CC, Haraszti CJ, McGillivary GR, et al. Intra-articular distal radius fractures: arthroscopic assessment of radiographically assisted reduction. J Hand Surg [Am] 2001; 26: 1036e41. 21 Luchetti R, Atzei A, Fairplay T. Arthroscopic wrist arthrolysis after wrist fracture. Arthroscopy 2007; 23: 255e60. 22 Osterman AL, Raphael J. Arthroscopic resection of dorsal ganglion of the wrist. Hand Clin 1995; 11: 7e12. 23 Viegas SF, Wagner K, Patterson R, Peterson P. Medial (hamate) facet of the lunate. J Hand Surg [Am] 1990; 15: 564e71. 24 Harley BJ, Werner FW, Boles D, et al. Arthroscopic resection of arthrosis of the proximal hamate: a clinical and biomechanical study. J Hand Surg [Am] 2004; 29: 661e7. 25 Topper SM, Wood MB, Ruby LK. Ulnar styloid impaction syndrome. J Hand Surg [Am] 1997; 22: 669e704. 26 Bain GI, Bidwell TA. Arthroscopic excision of ulnar styloid in stylocarpal impaction. Arthroscopy 2006; 22: 677.e1e3. 27 Bain GI, Begg M. Arthroscopic assessment and classification of Kienbock’s disease. Tech Hand Upper Extrem Surg 2006; 10: 8e13. 28 Menth-Chiari WA, Poehling GG, Wiesler ER, et al. Arthroscopic debridement for the treatment of Kienbock’s disease. Arthroscopy 1999; 15: 12e9. 29 Culp RW. Complications of wrist arthroscopy. Hand Clin 1999; 15: 529e35. 30 Pell RF, Uhl RL. Complication of thermal ablation in wrist arthroscopy. Arthroscopy 2004; 6: 84e6.
to the heat of the traction tower after sterilization (Figure 11). It is therefore mandatory to check the temperature of the tower before starting the procedure.
Summary As we come to understand wrist arthroscopy patho-anatomy better, and given the huge advances in technical devices, we are now able to perform new diagnostic and therapeutic procedures. The variety of treatments using wrist arthroscopy is expanding and brings new challenges, and also controversies. Wrist arthroscopy is the gold standard in the diagnosis and treatment of TFCC injuries. Excellent outcomes have been obtained with debridement in partial SLIL and LTIL ligament tears. However, in complete tears with static instability pattern, debridement should be augmented by pinning or by means of a headless compression screw (ARASL procedure). The use of the newer electro-thermal devices is promising; however, further investigation is needed to better define their efficacy and safety. The role of arthroscopy in the treatment of distal radius fractures should be individualized according to the patient and the surgeon, but according to published studies, can be of great help in verifying the existence of associated injuries and the correct articular reduction. Outcomes of dorsal ganglia arthroscopic resection show excellent results. Further studies are required to evaluate the role of arthroscopy in the management of volar ganglia. The clinical applications of wrist arthroscopy continue to expand, with more complex reparative, reconstructive, and salvage procedures. Future developments are likely to occur by adapting open reconstructive procedures into arthroscopic procedures. A
REFERENCES 1 Cheng YCh. Arthroscopy of the wrist and finger joints. Orthop Clin North Am 1979; 10: 723e33. 2 Weiss AP, Akelman E, Lambiase R. Comparison of the findings of triple-injection cinearthrography of the wrist with those of arthroscopy. J Bone Joint Surg [Am] 1996; 78: 348e56. 3 Cooney WP. Evaluation of chronic wrist pain by arthrography, arthroscopy, and arthrotomy. J Hand Surg [Am] 1993; 18: 815e22. 4 Bain G, Munt J, Turner PC. New advances in wrist arthroscopy. Arthroscopy 2008; 24: 355e67. ~al F, Garcia-Bernal FJ, Pisani D, et al. Dry arthroscopy of the 5 del Pin wrist: surgical technique. J Hand Surg [Am] 2007; 32: 119e23. 6 Viegas SF. Midcarpal arthroscopy: anatomy and technique. Arthroscopy 1992; 8: 385e90. 7 Puhaindran ME, Yam AK, Chin AY, Lluch A, Garcı´a-Elı´as M. Wrist arthroscopy: beware the novice. J Hand Surg [Eur] 2009; 34: 540e2. 8 Slutsky DJ. Volar portals in wrist arthroscopy. J Am Soc Surg Hand 2002; 2: 225e32. 9 Slutsky DJ. Clinical applications of volar portals in wrist arthroscopy. Tech Hand Upper Extrem Surg 2004; 8: 229e38. 10 Palmer AK. Triangular fibrocartilage disorders: injury patterns and treatment. Arthroscopy 1990; 6: 125e32.
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FURTHER READING ~al F, Mathoulin C, Luchetti R, eds. Arthroscopic management of Del Pin distal radius fractures. Heidelberg: Springer, 2010.
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(v) Unicompartmental knee arthroplasty
ligament was considered essential. Technical factors included the need to under-correct the coronal plane deformity and to avoid femoral component impingement on the patella. In addition, malalignment of the components led to edge loading, high contact stress, accelerated polyethylene wear and implant loosening. With respect to prosthesis design, increasing conformity of the femoral-tibial articulation in fixed-bearing designs7 and thin tibial polyethylene (<6 mm)8 were associated with high failure rates. Uncemented UKAs9 were less durable. Mobile-bearing components fared better than fixed.10 With the above in mind, improved understanding of surgical principles, surgical techniques and designs have led to excellent long-term results according to numerous published series, with 10year survivorship ranging from 91% to 100%, and 15-year survivorship of 93%.11 This has led to a resurgence in popularity of the use of UKA over high tibial osteotomy or total knee arthroplasty in younger patients with unicompartmental degenerative disease.
S Thambapillay G Chakrabarty
Abstract Unicompartmental knee arthroplasty (UKA) is a treatment option when only one compartment of the knee is affected with arthritis. There has been increasing enthusiasm in unicompartmental knee arthroplasty, with improved understanding of surgical principles, newer techniques for improving surgical precision including the use of smaller incisions, and the introduction of newer designs. Past experiences from several centres have been paramount in the education of surgeons with regards to patient selection, technical considerations, and importantly avoiding common pitfalls can lead to early failure of the components.
Patient selection The patient should have a diagnosis of osteoarthritis (OA), posttraumatic arthritis or spontaneous osteonecrosis involving only one compartment of the knee joint. Most importantly, the patient should have only unicompartmental pain, as can be demonstrated clinically with a positive ‘one finger test’. Usually, the patient points to the compartment with one finger compared with a ‘knee grab’, where the patient literally grabs the entire knee due to inability to localize the pain. The main clinical indications are: severe pain arising from one knee compartment, patients with a relatively sedentary occupation, any varus deformity should be less than 10 , the flexion range should be at least 90 , there should be no significant flexion contracture, the anterior cruciate ligament should be intact and any instability should be medial only. With improved reported survivorship in recent studies, patient selection has been extended to two further categories. First, UKA should be considered for the middle-aged patient with OA who desires a reliable initial result with retention of both cruciates and easy revision to total knee arthroplasty if necessary. The second group are elderly patients with severe medical co-morbidities. UKA may improve the patient’s lifestyle and reduce a significant amount of their ambulatory and rest pain. In addition, these patients are unlikely to survive the lifespan of the UKA. The patient should be counselled appropriately and be managed on an individual basis. Radiologically, the indications for UKA are 50% unicompartmental collapse (Ahlback I)12 or complete collapse (Ahlback II) on weight-bearing radiographs (Figure 1). Stress views may occasionally be indicated. Some surgeons perform initial arthroscopic assessment of the knee to assess the integrity of the anterior cruciate ligament and both the contralateral and the patellofemoral compartments. The contraindications include: inflammatory arthritis, decreased range of motion with flexion contracture, patients with a very active lifestyle (athletes/sports), obesity,
Keywords arthritis; arthroplasty; knee; unicompartmental
Introduction The concept of a knee hemiarthroplasty was introduced in the 1950’s, when a spacer was inserted in one half of the tibiofemoral joint to prevent bone-on-bone apposition. McKeever1 was the first to introduce his Vitallium (Zimmer Inc., Warsaw, IN) tibial plateau hemiarthroplasty in 1957, followed by MacIntosh,2 and the current-day version is the Unispacer (Smith & Nephew, Inc., Memphis, TN). Unfortunately, this implant has a very high failure rate and is no longer recommended.3 The Gunston,4 Marmor and polycentric unicompartmental knee arthroplasties were introduced in the early 1970’s. The revision rates were 10% at two-year follow-up.5 Following that, other reported series did not show encouraging results, with 70% survivorship at 5e7 years, and 65% survivorship reported at 11 years in the 1970’s and 80’s.6 The results were promising initially but when compared with total knee arthroplasty, the latter yielded superior outcomes. Many surgeons held reservations about UKA during the early stages due to this. Despite that, some held great enthusiasm towards the development of UKA. Much was learned from the early experiences. Patient selection was critical. Obese patients and patients with moderate to severe deformities did worse. Contralateral compartment degenerative changes were also considered a poor prognostic factor. An intact anterior cruciate
S Thambapillay MRCS Specialty Trainee Registrar, Orthopaedic Department, Huddersfield Royal Infirmary, Lindley, Huddersfield, Yorkshire, UK. G Chakrabarty D (Orth) MS (Orth) MCh (Orth) FRCS (Ed) FRCS Tr & Orth Consultant Orthopaedic Surgeon, Orthopaedic Department, Huddersfield Royal Infirmary, Lindley, Huddersfield, Yorkshire, UK.
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Figure 1 (a) Pre-operative radiographs of knee. (b) Post-operative radiographs of UKA.
coexistent patellofemoral arthritis, secondary osteonecrosis, and knee instability with absence of the anterior cruciate ligament. However, some centres have reclassified some of the above criteria as relative rather than absolute contraindications. Radiographic contraindications are grade IV Ahlback changes, with joint space obliteration, or medial-lateral subluxation of 3e4 mm or greater. Intra-operative findings are equally important and contraindications include significant involvement of the other compartment(s), an absent anterior cruciate ligament, and greater than 10 of varus deformity. Some surgeons are performing UKAs in patients with patellofemoral OA and/or ACL deficiency (the procedure being combined with reconstruction of the ACL), with promising reported results.13
a study comparing patients who had UKA in one knee and TKA on the contralateral side, there was a greater range of movement in the UKA side postoperatively.18 31% stated that their UKA knee was their better knee overall, 15% stated that their TKA knee was their better knee, and 54% could find no difference. These findings are probably due to the fact that UKA tends to preserve more normal knee kinematics better than does TKA.
Surgical techniques One of the key factors to the overall survival of the implants in UKA surgery is the level of experience of the surgeon, as this influences significantly the likely accuracy of component implantation and limb alignment. The ability to use a mini-incision technique, i.e. a short incision performed medial to the patellar tendon, with subluxation of the patella rather than dislocation or eversion of the patella, using appropriate modern instrumentation, is one of the key features that has led to a resurgence of UKA as an appropriate treatment option for unicompartmental arthritis versus TKA. Studies have shown faster recovery and shorter hospital stay in the mini-incision group versus TKA or versus UKA through a larger incision with eversion of the patella.19 Accuracy of UKA component implantation was the same with the mini-incision as it was with the standard (TKA-type) approach.
UKA versus high tibial osteotomy and total knee arthroplasty With improvement in the design and surgical techniques in UKA, and with promising long-term results, it is vital to compare and contrast the advantages and disadvantages of the UKA with High Tibial Osteotomy (HTO) and Total Knee Arthroplasty (TKA). The outcome following UKA compared with HTO in two different series revealed superior results with 5e17-year followups. These showed 80% 10-year and 65% 17-years survivorship for HTO, versus 86% 10-year and 88% 17-year survivorship for UKA, respectively.14,15 More intra- and post-operative complications were noted in the HTO group. Patients in the UKA group had a higher satisfaction score, quicker recovery, less blood loss, lower risk of infection and easier revision to total knee arthroplasty than patients with HTO. With respect to TKA, studies have shown comparable or even superior results with UKA.16,17 UKA allows preservation of bone stock, improved range of movement, reduced intra-operative blood loss, reduced inpatient stay and decreased cost. In
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Navigation assisted UKA surgery Several centres have already started to use navigated systems to assist minimally invasive UKA, and preliminary results have shown significant improvement in the alignment of the limb, in both the coronal and sagittal planes.20 Accuracy of implant alignment in arthroplasty surgery is of paramount importance, with well aligned prostheses giving better function and increased longevity.21 Navigation assisted surgery will probably be one of the future core elements of arthroplasty surgery.
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Implant design
implants and accuracy of surgical technique have made the wear rate in UKA comparable to that of primary TKR. Appropriate patient selection has also made a significant contribution to the improved survivorship of the UKA, for example the exclusion of patients with too high a body mass index.
Cemented versus uncemented Uncemented implants have fared badly compared to their cemented counterparts,9 with a higher rate of loosening and implant failure due to poor bony ingrowth. This is particularly noted in the metal-backed tibial components. Hence, it has become common practice to use cemented UKA implants.
Progression of contralateral compartment OA One of the commonest reasons for revision surgery is progression of the OA to the contralateral compartment. Initially, overstuffing of the implants in the medial compartment was thought to be a potential cause for contralateral disease progression, from increasing the load on to the lateral compartment (Figure 2). It is now appreciated that it is important to under-correct the coronal plane deformity and achieve optimal soft tissue balancing intraoperatively. One should also ensure that there are no significant degenerative changes in the contralateral compartment at the time of the UKA procedure. Early or mild patellofemoral osteoarthritis is a relative contraindication, and medial UKA should be avoided in patients with actual patellofemoral symptoms.
Fixed bearing versus mobile bearing The indications for the use of an implant with a mobile versus a fixed bearing are still not clear. The long-term results of mobile and fixed bearings are comparable, but there are significant differences in resulting knee joint kinematics, tribological properties and implant-associated complications. The mobile bearings in UKA restore the physiological joint kinematics better than fixed implants. The decoupling of mobile bearings from the tibial implant allows a high level of congruence with the femoral implant, resulting in larger contact areas than with fixed bearings. This fact, in combination with the more physiological joint kinematics, leads to less wear and a lower incidence of osteolysis with mobile bearings. Mobile-bearing articulations also allow a metal-backed component to be used with a composite thickness as thin as 6 mm. However, the potential disadvantages of mobile bearings are the higher complication and early revision rates resulting from bearing dislocation and impingement syndromes, often secondary to suboptimal implantation technique or instability. This problem has been largely overcome with improved implant design and instrumentation. In cases with ligamentous pathology, fixed bearings involve a lower complication rate. It seems that their use can also be beneficial in patients with a low level of activity, as problems related to wear may be of lesser importance for this subgroup. The decision as to whether to use mobile or fixed-bearing components can, therefore, be tailored to the individual patient’s circumstances.
Patellar impingement Patellar impingement can be a problem in lateral UKA, with some patients developing patellofemoral pain. However, this is rarely seen now with improvement in surgical expertise and newer implants. Malaligned components The main reason for component realignment is inexperience of the surgeon, particularly with the earlier instrumentation. This can lead to early failure of implants, increased polyethylene wear, impingement and dislocations of mobile-bearing designs, necessitating revision surgery. Fortunately, this has largely been overcome with improved modern instrumentation and with navigation surgery. Bearing dislocation Bearing dislocation is a problem that has been reported particularly in mobile-bearing designs, especially in lateral UKA. Fortunately, however, this is rarely seen nowadays.
Metal-backed versus polyethylene tibial tray Some surgeons are proponents of the use of metal-backed tibial components. With the metal-backed tibial tray, there is the potential for greater resection of the tibial bone stock, to be able to accommodate an appropriate thickness of the polyethylene insert (i.e. >6 mm). This diminution in bone stock may potentially make revision surgery technically more demanding. However, the Oxford UKA utilizes the metal-backed component with a mobile-bearing polyethylene insert (starting at 3 mm) with good long-term survival.22 In addition, with improvement in the design and manufacturing of the polyethylene, wear rates have been drastically minimized. The reported results for either type of component have been promising.
Failures of UKA Apart from the normal modes of failure inherent to any arthroplasty surgery, there are a few specific potential failure mechanisms with UKAs: Polyethylene wear and associated wear Polyethylene wear is generally one of the main reasons for revision surgery. Improved tribological properties of current-day
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Figure 2 Degenerative changes in contralateral compartment of the knee after medial UKA.
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Implant breakage Implant breakage is most commonly associated with implant malalignment, early wear and loosening, which can very occasionally lead to this catastrophic consequence.
Bony defects are occasionally noted in knees undergoing revision arthroplasty. Bone loss is usually classified according to the nature of the defect at the end of the preparation during revision surgery. Technical difficulties can arise but nevertheless, surgeons with a major interest in revision knee arthroplasty have often reported that bone defects have no major impact on the technical difficulty of revision surgery due to the improvements in implant designs. Many papers have shown comparable outcomes with revision surgery following UKAs versus total knee arthroplasty.23,24,25 The
Revision surgery Revision of unicompartmental knee arthroplasties may be undertaken for the above listed modes of failure. The commonest reasons for revision are progression of arthritis in the contralateral compartment and implant failure (Figure 3).
Figure 3 (a) X-ray showing loosening around a tibial implant. (b) Post-revision to total knee arthroplasty in same patient.
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majority of the patients had no defects or only contained osseous defects (78%) at revision surgery and were dealt with by performing routine arthroplasty.23 However, revision of UKA to another UKA is not advocated in current practice. These centres have also had good overall survivorship of the primary UKA. With improved designs of the modern revision implants (e.g. modularity, stems, metal wedges or steps with stems) that allow reconstruction, UKA is now a definite viable option for selected patients with unicompartmental pathology.
Learning points Indications for unicompartmental knee arthroplasty unicompartmental pathology from the following: C primary osteoarthritis C spontaneous osteonecrosis C post-traumatic arthritis
are
Patients undergoing UKA should have confirmed clinical and radiological evidence of symptomatic, isolated unicompartmental arthritis of the knee. UKA is contraindicated in patients with: C inflammatory arthropathy C secondary osteonecrosis C associated symptomatic patellofemoral arthritis C decreased range of movement with flexion contracture C varus deformity greater than 10
Lateral UKA Lateral UKA is performed less frequently and is technically more difficult than medial UKA. The ratio of lateral to medial UKA is 1:10. The surgical approach is either through the medial or lateral approach. Technically, the patella is more vulnerable to impingement on the leading edge of the femoral component. The wear pattern is more posterior than the medial compartment, and achieving mediolateral congruency is technically more demanding. It is usually indicated for primary osteoarthritis with relatively good results. However, the results are inferior when lateral UKA is undertaken for post-traumatic arthritis. Two longterm studies of lateral unicompartmental knee arthroplasty showed survival rates of 83% at 10 years and 74% at 15 years,26 and 100% at 12.4 years.27
Relative contraindications to UKA are: C ACL deficiency (although combined ACL reconstruction can be undertaken) C obesity C very young patients One should beware of patients with medial sided knee pain that might actually be referred pain from a stiff or arthritic hip. There is good evidence that UKA gives comparable or even superior outcomes compared to TKA for patients with unicompartmental arthritis of the knee, and it has been shown to be safe, reliable and repeatable. Many papers have shown comparable results with revision surgery following UKAs and total knee arthroplasties, and without major technical difficulties.
Patellofemoral UKA Several centres are currently performing patellofemoral UKA for isolated patellofemoral arthritis. The results have been promising, provided clear indicative criteria are met, with good patient selection.28 This particular topic is not dealt with in this paper as it merits separate dedicated review and discussion.
The future Unicompartmental knee arthroplasty has become an established and viable option over the last two to three decades for the treatment of unicompartmental OA. The long-term results to-date have been promising and the indications for the procedure are broadening.29,30 The future is likely to see refined criteria for patient selection and should bring better surgical techniques and prosthetic designs. Improved polyethylene will increase longevity of the prostheses, and mobile-bearing articulations may also extend longevity by decreasing wear and allowing a metal-backed component with relatively thin polyethylene inserts for a conservative arthroplasty. Ultimately, for UKA as for any joint arthroplasty, the aim is to perform the right operation for the right patient using the correct surgical technique and a proven implant design.
Research directions Longer term studies are required to: C compare fixed versus mobile-bearing implants C determine the potential value of computer aided surger
REFERENCES 1 McKeever DC. Tibial plateau prosthesis. Clin Orthop 1960; 18: 86e95. 2 MacIntosh DL, Hunter GA. The use of the hemiarthroplasty prosthesis for advanced osteoarthritis and rheumatoid arthritis of the knee. J Bone Joint Surg Br 1972; 54: 244e55. 3 Bailie AG, Lewis PL, Brumby SA, Roy S, Paterson RS, Campbell DG. The unispacer knee implant: early clinical results. J Bone Joint Surg Br 2008; 90: 446e50. 4 Gunston FH. Polycentric knee arthroplasty: prosthetic simulation of normal knee movement. J Bone Joint Surg 1971; 53B: 272. 5 Marmor L. Marmor modular knee in unicompartmental disease: minimum four-year follow-up. J Bone Joint Surg Am 1979; 61: 347e53.
Conclusion Unicompartmental knee arthroplasty is an excellent operation when undertaken by the right surgeon for the right patients meeting the appropriate criteria. It is a minimally invasive procedure with comparable or better outcomes compared with total knee replacements. Revision of unicompartmental knee replacements to total knee replacements is no longer considered a technically challenging concept in many knee centres. A ORTHOPAEDICS AND TRAUMA 25:6
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6 Marmor L. Unicompartmental arthroplasty of the knee with a minimum ten-year follow-up period. Clin Orthop 1988; 228: 171e8. 7 Batley RE, Stulberg SD, Robb III WJ, Sweeny HJ. Polyethylene wear in unicompartmental knee arthroplasty. Clin Orthop Relat Res 1994; 299: 18e24. 8 Knutson K, Jonsson G, Langer Anderson J, Larusdottir H, Lidgren L. Deformation and loosening of tibial component in knee arthroplasty with unicompartmental endoprosthesis. Acta Orthop Scand 1981; 52: 667e73. 9 Lindstrand A, Strenstrom A, Egund N. The PCA unicompartmental knee. a one to four year comparison of fixation with or without cement. Acta Orthop Scand 1988; 59: 695e700. 10 Argenson JN. Biomechanical study of the Oxford knee prosthesis with mobile meniscus. Chirurgie 1993e1994; 119: 268e72. 11 Khanna G, Levy BA. Oxford unicompartmental knee replacement: literature review. Orthopedics 2007; 30(5 suppl): 11e4. 12 Ahlback S. Osteoarthrosis of the knee. A radiographic investigation. Acta Radiol Diagn (Stockh) 1968; 277(suppl): 7e72. 13 Dervin GF, Conway AF, Thurston P. Combined anterior cruciate ligament reconstruction and unicompartmental knee arthroplasty: surgical technique. Orthopedics 2007; 30(5 suppl): 39e41. 14 Broughton NS, Newman JH, Baily RA. Unicompartmental replacement and high tibial osteotomy for osteoarthritis of the knee. A comparative study after 5e10 years’ follow-up. J Bone Joint Surg Br 1986; 68: 447e52. 15 Weale AE, Newman JH. Unicompartmental arthroplasty and high tibial osteotomy for osteoarthrosis of the knee. A comparative study with a 12- to 17-year follow-up period. Clin Orthop Relat Res 1994; 302: 134e7. 16 Emerson Jr RH. Unicompartmental mobile-bearing knee arthroplasty. Instr Course Lect 2005; 54: 221e4. 17 Hopper GP, Leach WJ. Participation in sporting activities following knee replacement: total versus unicompartmental. Knee Surg Sports Traumatol Arthrosc 2008; 16: 973e9. 18 Laurencin CT, Zelicof SB, Scott RD, Ewald FC. Unicompartmental versus total knee arthroplasty in the same patient. A comparative study. Clin Orthop Relat Res 1991; 273: 151e6.
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19 Price AJ, Webb J, Topf H, Goodfellow JW, Murray DW. Rapid recovery after oxford unicompartmental arthroplasty through a short incision. J Arthroplasty 2001; 16: 970e6. 20 Jenny JY, Ciaobanu E, Boeri C. The rationale for navigated minimally invasive unicompartmental knee replacement. Clin Orthop Relat Res 2007; 463: 58e62. 21 Konywes A, Willis-Owen CA, Spriggins AJ. The long-term benefit of computer-assisted surgical navigation in unicompartmental knee arthroplasty. J Orthop Surg Res 2010; 5: 94. 22 Simpson DJ, Gray H, D’Lima D, Murray DW, Gill HS. The effect of bearing congruency, thickness and alignment on the stresses in unicompartmental knee replacements. Clin Biomech (Bristol, Avon) 2008; 23: 1148e57. 23 Chakrabarty G, Newman JH, Ackroyd CE. Revision of unicompartmental arthroplasty of the knee. Clinical and technical considerations. J Arthroplasty 1998; 13: 191e6. 24 Dudley TE, Gioe TJ, Sinner P, Mehle S. Registry outcomes of unicompartmental knee arthroplasty revisions. Clin Orthop Relat Res 2008; 466: 1666e70. 25 Johnson S, Jones P, Newman JH. The survivorship and results of total knee replacements converted from unicompartmental knee replacements. Knee 2007; 14: 154e7. 26 Ashraf T, Newman JH, Evans RL, Ackroyd CE. Lateral unicompartmental knee replacement survivorship and clinical experience over 21 years. J Bone Joint Surg Br 2002; 84: 1126e30. 27 Pennington DW, Swienckowski JJ, Lutes WB, Drake GN. Lateral unicompartmental knee arthroplasty: survivorship and technical considerations at an average follow-up of 12.4 years. J Arthroplasty 2006; 21: 13e7. 28 Lonner JH. Patellofemoral arthroplasty. Instr Course Lect 2010; 59: 67e84. 29 Berend KR, Lombardi Jr AV, Adams JB. Obesity, young age, patellofemoral disease, and anterior knee pain: identifying the unicondylar arthroplasty patient in the United States. Orthopedics 2007; 30(5 suppl): 19e23. 30 Sah AP, Springer BD, Scott RD. Unicompartmental knee Arthroplasty in octogenarians: survival longer than the patient. Clin Orthop Relat Res 2006; 451: 107e12.
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(vi) An introduction to hip arthroscopy part one: surgical anatomy and technique
into hip arthroscopy has increased significantly over the last 10 years, and the number of indications has increased proportionately.1 As practical experience and the base of scientific evidence evolve, hip arthroscopy is likely to become an important procedure carried out by an increasing number of orthopaedic surgeons.
History Burman2 is credited as being the first to report on hip arthroscopy, although he concluded in his 1931 paper that it was “manifestly impossible to insert a needle between the head of femur and the acetabulum” and therefore not possible to visualize the acetabular fossa and its associated structures. Clinical application was first reported by Takagi3 in 1939, with a series of four cases involving two patients with Charcot joints, one with tuberculous arthritis and one with suppurative arthritis. It was not until the 1970’s that the clinical applications of hip arthroscopy were again mentioned and not until the 1990’s that the procedure became well established.4 With advances in imaging and arthroscopic instruments, the management of hip injuries has progressed considerably over the last two decades.5 The technique remains a challenge due to the bony and soft-tissue anatomy of the joint but is rapidly becoming the treatment of choice for a number of hip joint problems that would previously have required prolonged activity restriction or, in the event of failure of conservative management, an open procedure.6 The scientific literature on hip arthroscopy is expanding, with ever increasing studies documenting good long-term outcomes.7
Peter D H Wall Jamie S Brown Shanmugam Karthikeyan Matthew Wyse Damian Griffin
Abstract Although first described in the 1930’s, it was not until the late 20th century that hip arthroscopy became a well-recognized procedure. Correct patient positioning and portal placement are critical, and failure of either may result in inability to access the joint or damage to important local neurovascular structures. In the hands of an experienced surgeon and anaesthetist the risks are small, but attention to detail is critical. The future of hip arthroscopy is exciting and as the scientific evidence builds it is likely to be an important adjunct to more traditional open hip procedures.
Keywords arthroscopy; hip
Gross anatomy (Figures 1e5) Hip arthroscopy involves navigation of two areas, called the central and peripheral compartments. The peritrochanteric compartment can also be explored, but this does not form part of routine hip arthroscopy.
Introduction Arthroscopy is rapidly becoming an important technique in the management of a number of conditions affecting the hip. Research
Central Compartment
Peter D H Wall MBChB (Hon) MRCS (Edin) Hospital Health Sciences, The Division of Health Sciences, Warwick Medical School, University Hospital, Coventry, UK. Conflict of interest: none.
Zone for peritrochanteric compartment
Jamie S Brown MBChB BSc (Hons) Foundation Research Doctor in Orthopaedics at University Hospitals Coventry and Warwickshire, University Hospital, Coventry, UK. Conflict of interest: none.
Cotyloid fossa with fat pad
Fovea
Shanmugam Karthikeyan MBBS DOrtho MRCS Hospital Health Sciences, The Division of Health Sciences, Warwick Medical School, University Hospital, Coventry, UK. Conflict of interest: none.
Peripheral Compartment
Matthew Wyse MBBS FRCA Consultant in Anaesthesia at University Hospitals Coventry and Warwickshire, University Hospital, Coventry, UK. Conflict of interest: none. Damian Griffin BM BCh (Oxon) MA (Cantab) MPhil (Cantab) FRCS (Eng) FRCS (Tr & Orth) Hospital Health Sciences, The Division of Health Sciences, Warwick Medical School, University Hospital, Coventry, UK. Conflict of interest: Financial support from Voyant Health now Brainlab Department support from Wright Medical.
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Figure 1 Coronal section magnetic resonance imaging of hip.
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Peripheral Compartment
Central Compartment
Cotyloid fossa with fat pad
Figure 2 Axial section magnetic resonance imaging of hip.
Central compartment The central compartment is a potential space that lies between the surface of the femoral head and the acetabulum. The limit of this space is the labrum of the acetabulum, and the compartment itself comprises the articular surfaces and labrum. The surface of
Figure 4 (a) and (b) View of peripheral compartment during hip arthroscopy.
the acetabulum that is covered with articular cartilage is called the lunate surface (Figure 3a and b). This cartilage forms a horseshoe-shaped configuration and extends from the posteroinferior aspect to the antero-inferior aspect of the acetabulum. In the middle of the acetabulum, and therefore contained within the horseshoe of cartilage, is the cotyloid fossa. The fossa is usually easy to identify during arthroscopy because it contains a yellowish fat pad (Figure 3a). Also within the central compartment is the ligamentum teres, which is a large strap-like structure that connects the femoral head to the acetabulum. The attachment to the acetabulum is in
Figure 3 (a) and (b) View of central compartment during hip arthroscopy.
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Figure 5 View of peritrochanteric compartment during hip arthroscopy.
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the base of the cotyloid fossa and close to the posterior attachment of the transverse ligament (Figure 3a and b). The ligamentum teres is slightly broader at its connection to the acetabulum and typically covered in synovial membrane. The other attachment of the ligamentum teres is to a pit (the fovea) in the centre of the femoral head. Peripheral compartment The peripheral compartment refers to the remainder of the hip joint within the intra-capsular space, lateral to the labrum. It includes the area along the junction of the femoral head and neck. The anterior femoral neck, which can be examined during arthroscopy, is typically covered by shiny periosteum. The femoral neck widens to form the femoral head more medially. Laterally, the anterior capsule can be seen where it attaches to the inter-trochanteric line. There is a constriction around the capsule at the mid-portion of the femoral neck called the zona orbicularis (Figure 4a); from here, more medially the capsule expands again as it enters the perilabral recess. Within the peripheral compartment it is possible to see the outer surface of the anterior labrum. The iliofemoral ligament lies over the antero-superior capsule, where the capsule is thickened. The medial synovial fold, or Weitbrecht’s ligament, is a constant landmark on the inferior aspect of the femoral neck, and runs from the lateral capsular reflection of the inferior recess to the edge of the articular surface of the femoral head. The lateral synovial fold is less distinct but can be seen on the superior aspect of the femoral neck. This stricture is important, however, because it covers the terminal vessels of the ascending branch of the medial femoral circumflex artery as they pass along the femoral neck.
Figure 6 Supine patient positioning.
of the hip (where much of the pathology resides) and the limited possibility of fluid extravasation into the soft tissues and abdominal cavity as advantages.8 Lateral e (Figure 7) For the lateral approach, the patient is placed in the decubitus position with the operated hip uppermost. The foot is then strapped into the distraction device and the hip placed in slight abduction, flexion and lateral rotation, to relax the capsule. A similarly padded perineal post is placed between the legs and pushed upwards against the medial thigh of the operating leg. This produces internal distraction and again distances the post from the pudendal nerve. A trial of traction is carried out and joint distraction confirmed with the image intensifier. The hip is then prepped and draped and traction reapplied prior to the commencement of the procedure.9 Typically, traction forces of 100e300 N are used.10 The major advantage offered by the lateral approach is the dispersion of the fat envelope in obese patients. In this position, the fat drops away from the surgical site under the influence of gravity, allowing easier manipulation of the instruments and reducing the amount of tissue that must be traversed to reach the joint. Proponents of the lateral approach also feel the technique offers easier entry into the joint in those patients with anterolateral acetabular spurs, as the introduction of a posterior portal is easily possible.9 Figure 8 shows the general theatre setup, including positioning of the image intensifier equipment, for patients in the lateral position.
Peritrochanteric compartment (Figure 5) The lateral or peritrochanteric compartment lies outside of the hip joint and capsule. The peritrochanteric compartment is not a true anatomical space, and needs to be created by the operating surgeon. Using both a shaver and the arthroscope, a space is gently created superficial to the fascia lata within the fat.
Patient positioning Hip arthroscopy can be performed in either the supine or the lateral position. Each position has its advantages and disadvantages. Supine (Figure 6) For the supine approach, the patient is placed on the fracture table with a generously padded perineal post. The patient’s pelvis and trunk are then directed away from the operating side. This serves to lateralize the traction vector and also to distance the post from the pudendal nerve. The operating hip is placed in extension, 25 abduction and neutral rotation. The opposite hip is placed in abduction to allow placement of the image intensifier between the legs, with the foot anchored for counter traction. Traction is applied and joint distraction confirmed by fluoroscopy (approximately 100e300 N). Traction is then released. The hip is prepped and draped and traction reapplied when surgery is ready to begin.8 Proponents of the supine position cite the ability to use a standard fracture table, the good access to the anterior portions
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Figure 7 Lateral patient positioning.
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Portal positioning and relevant anatomy HT
Figure 9 is a diagrammatic representation of the arthroscopic portals that are used for the central, peripheral and peritrochanteric compartments, which will all be discussed in more details in this section.
Anterior Superior Iliac Spine HA
Central compartment portals Anterior: the traditional anterior portal is placed at the intersection of two imaginary lines: a horizontal line drawn from the symphysis pubis or the superior margin of the greater trochanter, and a vertical line projecting inferiorly from the anterior superior iliac spine. At this intersection, a needle is advanced towards the femoral head along a line 45 medial and 45 proximal to this point. The portal should advance along this same line and will sit medial to tensor fascia lata and lateral to sartorius. The portal will confer good visibility of the anterior part of the central compartment and to the anterior labrum.
APT
A
PT
PPT PL
Greater
MA
P
Trochanter LA
Modified anterior: the traditional anterior portal frequently damages the hip flexors and provides a suboptimal angle of entry into the central compartment. At our centre, the senior author uses a modified anterior portal that is about 2 cm inferior to and 1 cm more posterior than the traditional anterior portal.
LT
Figure 9 Schematic of portal positioning in relation to greater trochanter.
the centre of the acetabulum. It provides good visualization of the femoral head, fovea and anterior/posterior labral structures.
Anterior paratrochanteric: typically, the portal is placed 2 cm anterior to the anterior margin of the greater trochanter and approximately at the level of the tip of the greater trochanter. The projection should be in a postero-superior direction in order to prevent the anterior capsule being ripped. Although not always used as a portal in our centre, we typically use this portal site as the initial site for creating an air arthrogram and injecting local anaesthetic into the hip joint, because the risk of injuring local structures is relatively low and this aids subsequent portal placement.
Posterior paratrochanteric: this is typically inserted 2e3 cm posterior to the tip of the greater trochanter, at the level of the tip of the greater trochanter. The trocar should be directed slightly superior and anterior to avoid injuring the sciatic nerve. Avoiding hip flexion of more than 20 will minimize the risk of drawing the sciatic nerve into the field, and similarly allowing a small amount of internal rotation, which moves the greater trochanter anteriorly, will limit the chances of a trochar being directed towards the nerve.
Proximal trochanteric: this portal is positioned just superior to the tip of the greater trochanter, with a trochar directed towards
Posterolateral: this portal should sit about 3 cm posterior to the postero-superior edge of the greater trochanter. The level should correspond to the anterolateral portal. The initial needle should enter the joint at eleven o’clock, a point just posterior to the most superior aspect of the joint in the sagittal plane. In this position, the capsule is slightly thinner compared to the thicker capsule that lies anterior and merges with the iliofemoral ligament. Posterior: this portal has a high potential for injuring the sciatic nerve and superior gluteal vessels, and therefore an open approach can be used for insertion. An incision from the posterior aspect of the greater trochanter towards the posterior superior iliac spine is used. Gluteus maximus fibres are split, the short external rotators are retracted with particular care taken not to injure quadratus femoris, which is an important landmark for the medial circumflex femoral vessels. The capsule is exposed and instruments inserted. This portal will allow access to the posteroinferior recess of the hip. Byrd et al. performed a cadaveric study in 1995, assessing the proximity of portals to locally important neurovascular
Figure 8 Theatre set-up for patients in lateral position.
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structures. Typically, the anterior portal was 0.3 cm from branches of the lateral femoral cutaneous nerve and 3.2 cm from the femoral nerve. The lateral circumflex femoral artery was on average 3.7 cm from the anterior portal. The superior gluteal nerve was typically 4.4 cm superior to the posterolateral portal. The sciatic nerve averaged 2.9 cm from the posterolateral portal. The typical portals we use for hip arthroscopy in our centre are shown in Figure 10.
Low trochanteric: this portal should be placed approximately 8e10 cm distal to the most prominent part of the greater trochanter, in line with the long axis of the femur.
Technique Once the patient is in a satisfactory lateral position, the hip is placed in slight flexion, abduction and internal rotation. It is necessary to confirm that the hip can be distracted with images from the intensifier. The intra-articular negative pressure gradient generated should be released with an 18-gauge spinal needle and the surgeon should feel a give (a ‘pop’) as the needle breeches the capsule. In our centre, this first needle is inserted in the position that will allow conversion to an anterior paratrochanteric portal. Once the needle is in place, 20e30 ml of air is then injected and images from an intensifier confirm whether a successful air arthrogram has occurred. Local anaesthetic is also injected and correct intra-articular placement is confirmed with a fluid level visible on the image intensifier. In our unit, we then typically insert a further needle under image intensifier guidance in the position of a subsequent posterolateral portal. The first needle acts as a guide to allow triangulation into the hip joint. The position of the introducer needle can be confirmed with both coronal and sagittal radiographs of the hip. Once this cannulated needle is in place, subsequent removal of the needle and flow of fluid through the cannula confirms satisfactory placement. A guide wire is passed through the cannula and radiographs should demonstrate this wire passing into the cotyloid fossa, provided correct placement has been achieved. The initial cannulated needle is then removed and replaced with an arthroscopy cannula over the guide wire. The arthroscope can then be introduced. We typically insert the modified anterior portal next. A large 18-gauge needle is inserted using triangulation with the first portal. The needle should be seen under direct vision entering the angle between the femoral head and labrum. Both these portals require a small capsulotomy after initial placement, in order to improve the manoeuvrability of the arthroscope and portal. Further portals should be inserted with a similar technique, but final portal placement may now be possible under direct visualization from the preceding portals. The number of portals required really depends upon the type and location of intervention planned. Visualization of the hip should proceed in a systematic fashion in order not to miss pathology, and all findings in all areas of the hip should be documented (Figure 11). Both 30 and 70 viewing scopes can be used to achieve full visualization, the latter offering a wider field of view. It is necessary to have an experienced assistant who is able to also move the leg/hip in order to aid visualization of the hip joint. The interventional instruments are all specifically designed for hip arthroscopy and are longer than those for the knee, allowing them to traverse the significant soft tissue barrier outside the hip joint.
Peripheral compartment High anterior: the skin incision and initial needle position should be approximately 1e2 cm proximal and anterior to the anterior paratrochanteric portal. Typically, this is one third of the distance from the anterior superior iliac spine to the tip of the greater trochanter. The advantage of this position is that the portal only penetrates tensor fascia lata and avoids damaging gluteus medius. The needle should be aimed so that is will pass perpendicular to the femoral neck axis. Low anterior: this portal can use the same skin incision as the modified anterior portal but the direction of the needle is more posterior and less medial. The needle should aim for the heade neck junction. If you choose to use a separate skin incision it should be placed approximately 1 cm inferior and posterior to the modified anterior portal. Peritrochanteric compartment High trochanteric: this portal should be placed approximately 8e10 cm proximal to the most prominent part of the greater trochanter, in line with the long axis of the femur.
Central compartment (Figure 12) With adequate distraction, the articular surfaces should separate sufficiently to allow navigation of the central compartment. Pathology involving the articular cartilage or ligamentum teres
Figure 10 Portal Placement. MA ¼ modified anterior portal, AP ¼ anterior paratrochanteric portal, PL ¼ posterolateral portal.
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Figure 12 View of central compartment with a capsulotomy for portal placement.
following the same steps as used for the other compartments (guide wire and then portal placement). Depending upon the intervention required, the fascia lata can be incised to access the greater trochanter and gluteus medius muscle/tendon.
Anaesthesia Hip arthroscopy typically requires a general anaesthetic. Most patients are young and have an expectation to return to full mobility very soon after surgery. The literature concerning anaesthesia for hip arthroscopy is limited. However, some general principles and special considerations are essential in order to ensure hip arthroscopy proceeds safely. The anaesthetic technique used should aim to deliver minimal morbidity and rapid recovery through the use of short acting agents with a rapid recovery profile. Patients generally require muscle relaxation with non-depolarizing muscle relaxants in order to allow adequate distraction of the hip joint, although occasionally, small patients or patients with weak musculature might not require muscle relaxation. The introduction of Sugammadex, a specific
Figure 11 Warwick orthopaedics system for recording hip pathology.
can be assessed and managed by accessing this compartment. The labrum is also typically visualized from this compartment but can also be approached from the peripheral compartment. Peripheral compartment (Figure 13) The volume within the peripheral compartment can be increased and access improved by releasing the traction. Allowing some slight hip flexion also allows better access to the anterior femoral head neck junction, which is particularly important for the assessment and treatment of anterior cam type FAI. Typically, high anterior and low anterior portals are used for this compartment. For the initial high anterior portal, an 18-gauge needle is inserted so that it touches the superior femoral headeneck junction. The needle is then angled anteriorly, to enter the capsule and slide down over the anterior femoral neck. A subsequent guide wire will allow the portal to be placed. The low anterior portal is then positioned by passing an 18-gauge needle to enter the capsule and inferior aspect of the neck at the inferior capsular reflection. Both these high and low anterior portals require a capsulotomy of approximately 1 cm to improve instrument manoeuvrability. Lateral/peritrochanteric compartment (Figure 7) The surgeon may enter the lateral compartment with the arthroscope to evaluate and treat disorders such as snapping hips, piriformis syndrome and trochanteric bursitis. Using two portals (the high and low trochanteric), most pathology can be assessed and treated. No image intensification is required. An 18-gauge needle is inserted for both the high and low trochanteric portal positions,
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Figure 13 Peripheral compartment, showing femoral headeneck junction after CAM bumpectomy.
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REFERENCES 1 Lubowitz JH, Poehling GG. Hip arthroscopy: an emerging gold standard. Arthroscopy 2006; 22: 1257e9. 2 Burman MS. Arthroscopy or the direct visualization of joints: an experimental cadaver study. J Bone Joint Surg Am 1931; 13: 669e95. 3 Takagi K. The arthroscope: the second report. J Jpn Orthop Assoc 1939; 14: 441e66. 4 Byrd JW, Chern KY. Traction versus distension for distraction of the joint during hip arthroscopy. Arthroscopy 1997; 13: 346e9. 5 Shindle MK, Voos JE, Heyworth BE, et al. Hip arthroscopy in the athletic patient: current techniques and spectrum of disease. J Bone Joint Surg Am 2007; 89(suppl 3): 29e43. 6 Tibor LM, Sekiya JK. Differential diagnosis of pain around the hip joint. Arthroscopy 2008; 24: 1407e21. 7 Byrd JWT, Jones KS. Prospective analysis of hip arthroscopy with 10year follow-up. Clin Orthop Relat Res 2010; 468: 741e6. 8 Byrd JWT. Hip arthroscopy by the supine approach. Instr Course Lect 2006; 55: 325e36. 9 Glick JM. Hip arthroscopy by the lateral approach. Instr Course Lect 2006; 55: 317e23. 10 Griffin DR, Villar RN. Complications of arthroscopy of the hip. J Bone Joint Surg Br 1999; 81: 604e6. 11 Lee EM, Murphy KP, Ben-David B. Postoperative analgesia for hip arthroscopy: combined L1 and L2 paravertebral blocks. J Clin Anesth 2008; 20: 462e5.
binding agent for Rocuronium, into UK clinical practice has allowed deeper levels of muscle relaxation to be maintained during anaesthesia with rapid reversal at the end of the case. Patients should receive adequate supplementary warming (warm theatre, warm air flow blankets and warm irrigation fluid) because exposure of the body and lower limbs plus large volumes of irrigation fluid have a cooling effect on the body. Regular monitoring of core body temperature is essential, not only to ensure adequate warming but also to help detect any early signs of extravasation of irrigation fluid. This is a rare but potentially life threatening complication. Post-operative pain is generally managed with a non-opiate based technique involving intra-articular and portal local anaesthesia, paracetamol and non-steroidal anti-inflammatories, given pre- or intra-operatively. Oral opiates, such as oral morphine solution, are prescribed as rescue analgesia postoperatively. Topical cooling applied to the hip post-operatively helps to reduce inflammation and pain. Lee and Ben-David (2008) reported favourable results from the use of a combined L1 and L2 paravertebral block, to ensure adequate post-operative analgesia11; however, this is not a technique that is used routinely in our centre. Post-operative nausea and vomiting appears to be a relatively rare occurrence. In our practice, most hip arthroscopy patients have an overnight stay to facilitate physiotherapy but the procedure may be performed as a day case or 23-h stay.
Summary
Acknowledgements
Hip arthroscopy has evolved rapidly over the last decade, with significant advances in instrumentation. Despite many equipment advances, hip arthroscopy remains a technically demanding procedure that although no longer necessarily confined to specialist units, does require a significant amount of training and experience. In experienced hands and with appropriate and safe patient positioning and portal placement, the indications and potential interventions that can be achieved are diverse. A
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The authors wish to thank Mr Jason McAllister, Graphic Designer in Medical Illustration at University Hospitals Coventry and Warwickshire, for producing the illustrations in this review. No benefits in any form have been received or will be received from any commercial party related directly or indirectly to the subject of this article.
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(vii) Radiology Quiz: Lower limb amputation stump pain
and ultrasound may therefore be required in cases that are not clear cut. The following four cases, presented in a quiz format, demonstrate the common causes of stump pain.
Bahir Almazedi James J Rankine Question 1 A 61 year old man, 15 months following above knee amputation, presented with distal femoral pain and crepitus. Figure 1a and b are the plain radiographs. The skin overlying the stump was slightly erythematous but the blood inflammatory markers were normal. Describe the abnormality. What other investigation might you consider?
Abstract Stump pain following lower limb amputation is common. Correct management relies on an accurate diagnosis of the underlying aetiology. The radiological diagnosis of the main causes of stump pain is discussed, with cases presented in a quiz format.
Keywords lower limb amputation; magnetic resonance imaging; radiology
Introduction Stump pain is related to the response of the bone and soft tissues to trauma, surgical treatment and underlying disease processes. It is a common complication of lower limb amputation, with a reported incidence ranging between 48% and 69%,1e3 Furthermore it seriously affects the patient’s quality of life and may interfere with prosthetic fitting.4,5 It is vital, therefore, to identify the cause of stump pain to provide the appropriate treatment to relieve the pain. The commoner causes of stump pain are neuromas, heterotopic ossification, and infection (abscess and osteomyelitis). Other causes include: bursitis, non-specific inflammation, scar tenderness, muscle tears, tendinitis, stress fractures, and neoplastic recurrence.6 Plain radiography, ultrasound and MRI can all be used in the investigation of stump pain. Plain radiography is usually the first-line investigation, as it is easily accessible, cheap and may reveal the cause of pain, for example heterotopic ossification or bony spurs.6 MRI is the most sensitive investigation for identifying both soft tissue and bone abnormalities.7 It is more sensitive than ultrasound in detecting osteomyelitis.8 However, MRI may demonstrate several abnormalities at the same time in a patient with stump pain and it may be difficult to identify which is causing the pain. Ultrasound, although a less sensitive test, is not limited to the detection of soft tissue abnormalities. Probe pressure can be used to elicit the patient’s symptoms and help identify whether an abnormality that is visualized is clinically relevant.9 A combination of MRI
Bahir Almazedi MB ChB MRCSEd Specialist Registrar, Radiology Academy, Clarendon Wing, Leeds General Infirmary, Great George Street, Leeds, LS1 3EX, UK. James J Rankine MD FRCR Consultant Radiologist, Radiology Academy, Clarendon Wing, Leeds General Infirmary, Great George Street, Leeds, LS1 3EX, UK.
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Figure 1 a AP and b lateral radiographs 3 years following an above knee amputation.
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Question 2
bone oedema, either within the femoral stump or within the heterotopic new bone formation and there is therefore no evidence of osteomyelitis. The low grade oedematous change in the soft tissues is in keeping with mechanical irritation related to the heterotopic bone formation. The small fluid collection is a soft tissue bursa. These features, along with the normal blood inflammatory markers, reliably exclude infection. In some cases the mechanical soft tissue inflammatory changes are only resolved by revision of the amputation stump.
A 47 year old male patient presented three years after an above knee amputation with a painful and tender stump. Plain films were normal. Figure 2 is an ultrasound scan of the stump with colour Doppler applied. Describe the abnormality and what is the diagnosis?
Figure 2 Ultrasound scan with colour flow Doppler.
Question 3 A 73 year old male with a right above knee amputation following Ewing’s sarcoma of the right calf, presented two years later with stump pain. There was no evidence of cellulitis. Figure 3a and b is from an MRI of the stump. Describe the abnormality. What is the diagnosis?
Question 4 A 67 year old man with a right below knee amputation secondary to trauma 30 years previously, presented with a one week history of skin erythema and tenderness at the stump site. There was a skin sinus at the stump tip, which was discharging. Radiographs were normal. Figure 4a, b and c is taken from MRI scans of the stump. Describe the abnormalities. What is the diagnosis?
Answers 1 e Heterotopic ossification There is evidence of new bone formation at the distal end of the femoral remnant. This is well formed, mature-looking bone with no evidence of osteolysis of the underlying femur. Radiographs are notoriously unreliable in diagnosing osteomyelitis and, whilst the features here are not suggestive of infection, the presence of erythema was clinically of concern. The patient therefore underwent an MRI examination, which is the most sensitive test for bone and soft tissue infection. Figure 5a is a T1-weighted MRI scan that shows new bone formation medial to the distal end of the femur (arrows). Figure 5b is a STIR sequence, a T2-weighted fat saturated sequence, which is very sensitive at detecting oedema. This shows oedema surrounding the new bone formation. There is a small pocket of fluid within the soft tissues (arrow). There is no
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Figure 3 a T1-weighted MRI. b T2-weighted fat saturated MRI.
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Figure 5 a T1-weighted MRI. b T2-weighted fat saturated MRI.
2 e Sciatic nerve neuroma A well-defined, oval hypoechoic mass with no flow expanding from an isoechoic striated linear structure. Figure 2 shows the ‘mouse sign’ (oval body attached to a tail), which is the classical description of a sciatic neuroma on ultrasound.9 Figure 6a is a T1-weighted MRI sequence of the same patient, which shows a low signal rounded mass (arrow) at the termination of the sciatic nerve (arrow heads). Figure 6b is a T2-weighted fat suppressed MRI image showing the same mass as high signal (arrow) indicating a mass with relatively high water content. A neuroma is a benign tumour composed of axons, Schwann cells, blood vessels and fibrous tissue and is considered to be the
Figure 4 a T1-weighted MRI. b T2-weighted fat saturated MRI. c T1weighted fat saturated post gadolinium MRI.
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interferes with their mobility. This can significantly affect the patient’s quality of life. The patient in this case declined the offer of surgical resection and is being managed in the meantime by ultrasound guided steroid injections. 3 e Soft tissue bursa at the tip of the femoral stump Figure 7a is a T1-weighted MRI sequence showing an oval shaped mass to the lateral side of the tip of the femoral stump. It has a low signal central component, which is fluid (arrow). Figure 7b is a T2-weighted fat suppression MRI sequence, which shows the central component as high signal confirming that it is a fluid-filled structure (arrow). There is no oedematous change in the surrounding soft tissues or within the bone and there is therefore no evidence of infection. These are the appearances of a simple mechanical bursa, which commonly occurs at the tip of the femoral stump. In some cases adjustments to the prosthesis can relieve the mechanical pressure which has caused the bursa to form. 4 e Abscess at the tip of the tibial stump with an adjacent sinus Figure 8a is a T1-weighted MRI, which demonstrates diffuse low signal change (arrow) of the subcutaneous fat overlying the stump. Normal fat on a T1-weighted sequence would be high signal. In this case the soft tissue inflammatory change results in low signal, fluid being dark on a T1-weighted sequence. Figure 8b is a STIR sequence; a T2-weighted with fat saturation. The areas that were dark on the T1-weighted sequence appear bright on the STIR sequence. In addition there is a focal area of higher signal, suggesting a fluid collection (arrow). This is confirmed on the T1weighted fat saturated post gadolinium sequence (Figure 8c). The abscess is seen clearly as an area of low signal (arrow), surrounded by diffuse high signal change. There is a sinus extending to the skin surface at the very edge of the image. The main role of gadolinium in these cases is to delineate soft tissue abscesses. These are clearly defined as areas of low signal, since collections of pus do not have a blood supply, surrounded by high signal from the hyperaemic inflammatory tissues. Compare these appearances with Figure 7b, which was a soft tissue bursa without infection. In that case a fluid collection was surrounded by normal tissues with none of the inflammatory changes seen in this case. The distinction between soft tissue mechanical change and low grade chronic infection may not always be as clear cut as in these cases. As in most areas of diagnostic imaging it is important to correlate the appearances with the clinical features, and specifically in these cases with the blood inflammatory markers. Incidental note is made of multiple patchy areas of signal change in the femur on all sequences. These appearances are in keeping with areas of hyperaemia as a result of disuse osteoporosis and raise the possibility of Reflex Sympathetic Dystrophy.
Figure 6 a T1-weighted MRI. b T2-weighted fat saturated MRI.
Summary Plain radiographs are usually the first-line investigation for stump pain after amputation, but they are obviously limited in the assessment of soft tissue changes. Heterotopic new bone formation is readily seen on radiographs, but it is very common and not always clinically relevant. It is often necessary to demonstrate the overlying soft tissue mechanical inflammatory changes by ultrasound or MRI. Ultrasound can be useful in localizing the source of
nerve’s attempt at regeneration following perineural damage.4,9,10 Neuromas are a common complication of limb amputation and they should be regarded as a consequence of normal healing responses.10 They are often asymptomatic, but patients wearing prosthetic limbs may experience pain that
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Figure 7 a T1-weighted MRI. b T2-weighted fat saturated MRI.
pain to a particular bursa or neuroma by employing probe pressure. Scar tissue, neuromas and bursae can be asymptomatic and the demonstration of multiple abnormalities on MRI may not be clinically helpful. Ultrasound can also be used to direct aspiration of soft tissue abscesses if a microbiological diagnosis is being sought. For the assessment of infection MRI is the preferred imaging modality, since it is the most sensitive test of both bone and soft tissue inflammatory change. A ORTHOPAEDICS AND TRAUMA 25:6
Figure 8 a T1-weighted MRI. b T2-weighted fat saturated MRI. c T1weighted fat saturated post gadolinium MRI.
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REFERENCES 1 Wartan SW, Hamann W, Wedley JR, McColl I. Phantom pain and sensation among British veteran amputees. Br J Anaesth 1997; 78: 652e9. 2 Kooijman CM, Dijkstra PU, Geertzen JH, Elzinga A, van der Schans CP. Phantom pain and phantom sensations in upper limb amputees: an epidemiological study. Pain 2000; 87: 33e41. 3 Gallagher P, Allen D, Maclachlan M. Phantom limb pain and residual limb pain following lower limb amputation: a descriptive analysis. Disabil Rehabil 2001; 23: 522e30. 4 Kitcat M, Hunter JE, Malata CM. Sciatic neuroma presenting forty years after above-knee amputation. Open Orthop J 2009 Dec 30; 3: 125e7. 5 Fischler AH, Gross JB. Ultrasound-guided sciatic neuroma block for treatment of intractable stump pain. J Clin Anesth 2007 Dec; 19: 626e8.
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6 Henrot P, Stines J, Walter F, Martinet N, Paysant J, Blum A. Imaging of the painful lower limb stump. Radiographics; 2000 Oct. 20 Spec No: S219eS235. 7 Foisneau-Lottin A, Martinet N, Henrot P, Paysant J, Blum A, Andre JM. Bursitis, adventitious bursa, localized soft-tissue inflammation, and bone marrow edema in tibial stumps: the contribution of magnetic resonance imaging to the diagnosis and management of mechanical stress complications. Arch Phys Med Rehabil 2003 May; 84: 770e7. 8 Boutin RD, Pathria MN, Resnick D. Disorders in the stumps of amputee patients: MR imaging. Am J Roentgenol 1998; 171: 497e501. 9 Ernberg LA, Adler RS, Lane J. Ultrasound in the detection and treatment of a painful stump neuroma. Skeletal Radiol 2003 May; 32: 306e9. Epub 2003 Feb 7. 10 Donnal JF, Blinder RA, Coblentz CL, Moylan JA, Fitzpatrick KP. MR imaging of stump neuroma. J Comput Assist Tomogr 1990 JuleAug; 14: 656e7.
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(viii) Blount’s disease
varus due to rickets. The main differential diagnosis in toddlers is physiological varus.
T Nunn
Physiological varus
P Rollinson
Knowledge of the developmental norms of angulation in the coronal plane is essential for identifying those with disease. Salenius and Vankka1 conducted a radiological assessment of coronal plane changes at the knee in 1279 Swedish children during growth. The tibio-femoral angle (angle subtended between the anatomic axis of the tibia and femur) for both girls and boys at birth was found to be on average 15 varus. Between the age of 18 months and 2 years this angle had reduced to 0 and by the age of 3 had reversed to 10 of valgus. A constant adult valgus angle of 6 was reached by the age of 7 (Figure 3). Salenius showed that in early childhood, varus angulation is expected, a feature that has come to be called ‘physiological varus’. There is a wide degree of variation of normality. In Salenius’s series, standard deviations around mean angles were found to be 8 . The greatest variations from mean values were found in boys and younger children. Younger children also have some normal femoral bowing, which makes accurate measurement problematic. It is therefore not easy to differentiate normal physiologic varus bowing (which will spontaneously correct) and pathological bowing in the child under the age of 2. However, a number of specific clinical and radiological features can help identify those with Blount’s disease.
B Scott
Abstract Blount’s disease is an uncommon disorder of the postero-medial proximal tibial physis, which produces a varus proximal tibia, tibial internal torsion, procurvatum and shortening. Blount described infantile and adolescent types. The precise pathogenesis of the condition remains obscure but associations include an early walking age, obesity, familial tendency and Afro-Caribbean race. It is frequently bilateral. The diagnosis of Blount’s disease follows clinical assessment and radiographs of the knee, which show a progressive varus deformity and typically an increased metaphyseal-diaphyseal angle. The natural history of the condition is adult knee pain, deformity and arthrosis. Treatment is dependent on the age of the child, the stage of the disease and the amount of angular and articular deformity present. Bracing may be used for early stage infantile disease. Surgical treatment options include hemiepiphysiodesis, osteotomy and bar excision. Monitoring of limb alignment and length is required until skeletal maturity.
Keywords Blount disease [MeSH]; genu varum; physiological varus
Diagnosis and classification W.P. Blount, a physician from Milwaukee, Wisconsin, was the first to fully describe the condition in 1937.2 He noted that progressive varus deformity was associated with an abnormal proximal medial tibial epiphysis. Radiographic features are medial epiphyseal sloping with associated beaking of the metaphysis. The tibio-femoral varus angle is most accurately determined with the patellae (rather than the feet) facing forwards and the knees fully extended. An early indicator of Blount’s disease is an increase in the metaphyseal-diaphyseal angle (of Drennan), which describes the angle between a line perpendicular to the anatomical tibial axis and a line joining the medial and lateral metaphysis (Figure 4). An angle greater than 11 was thought to be indicative of Blount’s.3 Feldman4 later revised this to an angle greater than or equal to 16 , which was more specific for the condition. In practice, sequential standing radiographs are useful in determining progression in equivocal cases. Another measured radiographic marker to aid diagnosis in the younger child is the epiphyseal-metaphyseal angle (Figure 4). An angle greater than 20 suggests that Blount’s is the cause of the varus.5 Typical radiographic features of Blount’s disease are: Metaphyseal beaking Apparent fragmentation of the medial metaphysis adjacent to the physis Straight lateral cortical wall of the proximal tibial metaphysis Subluxation of the proximal tibial laterally Increase in the metaphyseal-diaphyseal angle >16 Increase in the epiphyseal-metaphyseal angle >20 . In infantile Blount’s (under 4 years) the radiographic progres€ld into sion of the disease can be classified according to Langeskio six stages (Figure 5), ranging from mild involvement with a beaked medial metaphysis (Stage 1) to the presence of a transphyseal bony
Assessment of childhood varus The assessment of a child presenting with a varus knee requires taking a full history of the deformity, associated symptoms such as pain, gait problems, developmental delays, trauma, infection, and whether there is any associated dysplasia. A focussed clinical examination includes measuring weight, looking for a varus thrust and determining the standing varus angle with the knee in full extension. Assessment of ligamentous function and evaluation of the rotational profile should also be performed. Radiographs are helpful if there is: severe genu varum rapidly worsening deformity height <25th percentile marked asymmetry. It is also useful to note the site of angulation. A sharp angulation may indicate a focal physeal problem such as Blount’s (Figure 1). A more gradual bow is more often seen in conditions such as rickets (Figure 2). Serum chemistry may help identify
T Nunn FRCS (Orth) Orthopaedic Registrar, Leeds General Infirmary, UK. Conflict of interest: none. P Rollinson FRCS (Orth) Chief Specialist in Orthopaedics, Ngwelezane Hospital, South Africa. Conflict of interest: none. B Scott FRCS (Orth) Paediatric Orthopaedic Consultant, Leeds General Infirmary, UK. Conflict of interest: none.
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Figure 1 Clinical picture and radiograph of a child with severe bilateral Blount’s disease, showing a focal metaphyseal angular deformity.
bar (Stage 6).6 The classification is used as a reference guide to aid diagnosis, monitor progression and guide treatment. However, the interobserver variability for this classification on plain radiographs €ld stages,7 and was shown to be poor for the intermediate Langeskio it’s applicability to non-white populations has been questioned.8 A similar deformity was also described by Blount in a prepubertal adolescent group. The age of onset for this group was between 6 and 12 years in Blount’s original series2 and the cause of the deformity was hypothesized to be different. A juvenile variety of Blount’s, which typically occurs between ages of 4 and 6, is also described. Determining when the deformity started is difficult.
Some authors have changed the terminology to ‘early’ and ‘late’ onset Blount’s, occurring before and after the age of 4 years respectively.9 For the purposes of this review, Blount’s original terminology is used.
Pathogenesis Infantile Blount’s The cause of infantile Blount’s disease is postulated to be multifactorial. Recognized associations are Afro-Caribbean race, early walking age and abnormally increased body weight.9 A genetic link has been suggested, as a familial tendency is reported.10 Abnormal mechanical compressive loading of the physis is often implicated, as the disease has not been reported in those that do not walk. Cook et al.,11 using finite element analysis, showed that abnormal static varus alignment of 10 at the age of 2 years (when normal alignment should have progressed into a valgus posture) can produce sufficient compressive load to suppress medial physeal growth. This is in accordance with the HuetereVolkmann principle, which states that excessive compression through a physis produces growth inhibition by altering the structure and function of chondrocytes. A combination of mechanical and biological factors probably causes Blount’s disease. Abnormal growth is also recognized in other physes. Varus deformity of the distal femur is recognized,12 as well as increased anteversion at the hip,13 which may contribute to the negative foot progression angle. A compensatory valgus deformity at the ankle has also been reported.14 Internal torsion of the tibia is a consistent finding in Blount’s disease, and tibial shortening of 2e3 cm is commonly seen in unilateral cases. Adolescent Blount’s Adolescent Blount’s has many of the features of the infantile variety but bilateral involvement is seen in only 20% of cases compared with 80% in the infantile group.15 Pain may be a presenting feature and obesity is common. Males are more commonly affected. The condition tends to be milder and deformities greater than 25 are uncommon in adolescent Blount’s, as are physeal bars. Blount suggested trauma and infection as possible causes but most patients
Figure 2 Clinical illustration of rickets, showing a more gradual angular deformity.
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Mean Angular Changes in the Coronal Plane at the Knee Acording to Age
20 Degrees Varus 15 10 5 0 0
2
4
6
8
10
12
14
-5 -10 Degrees Valgus -15
AGE
Figure 3 Graph of the physiological angular changes found during childhood, as based on the work of Salenius and Vankka.1
have no history of such events. Kline12 has shown that distal femoral varus is more commonly seen in adolescent Blount’s, being present in a third of cases. Another recognized difference compared with the infantile variety is that static varus alignment is not a prerequisite for development of the adolescent form. Mechanical factors are still important and dynamic varus stresses due to a ‘fat thigh’ gait may be a factor in causing adolescent Blount’s.16 It is believed that the incidence of Blount’s is increasing in societies where childhood obesity is also increasing.17 Table 1 lists the various differences between infantile and adolescent Blount’s disease.
Histology The histology of Blount’s shows changes predominantly in the reserve zone of the physis. Islands of both acellular fibrous cartilage and hypertrophic densely packed cells are found with abnormal groups of capillary vessels. Avascular necrotic changes typical of osteochondrosis are not a feature.
Treatment The rationale for early treatment of varus malalignment is not only to correct a significant cosmetic deformity, but also to restore mechanical alignment before skeletal maturity to reduce the risk of early onset degenerative change. The relationship between deformity and subsequent degenerative change has not been so clearly defined as in the hip joint but the risk has been estimated to be >40% in those over the age of 30 years.18 Non-surgical treatment of Blount’s is recommended up to the age of 3 by some authors when distinguishing from physiological varus is problematic.19 Bracing Bracing treatment aims to reduce load on the medial physis and has been used with some reported success in stages I and II Blount’s, as
Figure 4 Radiographs of a 3-year-old with Blount’s. The metaphyseal beak is illustrated. The mechanical tibio-femoral angle (a) is the angle between a line drawn from the centre of the hip to the centre of the knee and a line drawn from the centre of the knee to the centre of the ankle. Drennan’s metaphyseal-diaphyseal angle (b) is the angle between a line drawn through the most distal aspects of the medial and lateral beaks of the proximal tibial metaphysis and a line perpendicular to a line drawn along the lateral aspect of the tibial diaphysis.3 The epiphyseal-metaphyseal angle (c) is created by a line drawn through the proximal tibial physis, parallel to the base of the epiphyseal ossification centre, and a line connecting the midpoint of the base of the epiphyseal ossification centre with the most distal point on the medial beak of the proximal tibial metaphysis.
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€ld stages of infantile Blount’s.6 Stage I e Figure 5 The six Langeskio Beaked metaphysis, Stage II e Saucer shaped defect, Stage III e Stepped defect, Stage IV e Bent physeal plate, Stage V e Double epiphysis, Stage VI e Medial physeal bar.
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Repeated surgery is often required, and this should be explained to the family, with possible time frames. Differential growth occurring in the proximal tibial physis will inevitably mean deformity recurrence. Therefore, surgical success of simple realignment procedures in childhood is dependent upon the growth potential within the medial physis. Surgical correction comprises three broad categories: Hemiepiphysiodesis Osteotomies Bony bar resection. These techniques may be used in combination.
Differences between Infantile and Adolescent Blount’s Infantile Blount’s
Adolescent Blount’s
Starts age <4 80% bilateral Progresses to physeal bar formation Associated with distal femoral valgus Tibial torsion and procurvatum substantial
Starts age >6, male predominance 80% unilateral Physeal bar not commonly seen Associated with distal femoral varus Tibial torsion and procurvatum mild
Hemiepiphysiodesis of the lateral tibial epiphysis relies on some residual growth on the medial side to correct the deformity. As medial physeal growth is reduced or even absent, the ability to correct a deformity is less predictable in Blount’s compared with other situations. In a series of 35 limbs treated with lateral hemi eda21 noted a mean correction epiphysiodesis for Blount’s, Castan of 3 at 30 months compared with 29 for those who did not have Blount’s. As a treatment in isolation, lateral hemiepiphysiodesis is probably effective for treating mild varus deformities only and will at least prevent progression of deformity. Such procedures require careful patient selection and vigilant follow-up. The advantage of this procedure is that it is minimally invasive.
Table 1
the deformity may be reversible. Bracing involves long-leg, lockedknee braces with a pelvic band to control rotation, which should be worn while child is weight bearing. Obesity (body mass index €ld greater then 90th centile), varus thrusting gait and Langeskio stage III are risk factors for the failure of non-surgical treatment.20 The effectiveness of a standardized bracing technique against a control group in a randomized trial has not yet been reported.9 Factors that increase the indication for surgical intervention are: progressing tibio-femoral angle greater than 15 varus metaphyseal-diaphyseal angle greater than 16 metaphyseal-epiphyseal angle greater than 30 significant depression of the medial tibial plateau ligamentous laxity of the knee.
Single osteotomy: a number of techniques have been described for single osteotomy. A simple opening wedge with external rotation is typically used in infantile Blount’s. Here, an overcorrection into valgus is recommended, to prevent recurrent deformity.22 The opening wedge also lengthens the limb, which is important in unilateral cases. The earlier in the disease stage this is performed, the less the need for further surgical correction.23 Figure 6 shows a single osteotomy below the level of the tuberosity. A fibular osteotomy has been performed to allow for rotational correction and a segment taken to use as struts to support the opening wedge.
Surgical correction The aim of surgical correction is to obtain legs that, at skeletal maturity, have a normal mechanical axis, normal sagittal and rotational profiles and are of equal length. The following general principles should be borne in mind when considering surgical correction: Surgery is best undertaken as soon as the diagnosis is made, with a better prognosis after early correction.
Figure 6 A single osteotomy below the level of the tibial tuberosity, with pre- (a) and post-operative (b & c) images. The fibula was harvested and used to create struts to support the opening wedge osteotomy. A plaster change was performed with fluoroscopy in theatre at 2 weeks to maintain the correction.
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A prophylactic subcutaneous anterior compartment fasciotomy is performed in all cases to reduce the risk of compartment syndrome.22 In this case a plaster was used to maintain the alignment and changed at the 2-week stage in theatre. However, stabilization with cross ‘K’ wires, plates and external fixation devices have also been described. Other single osteotomy types are the closing wedge (Figure 7), dome osteotomy and the oblique plane osteotomy. The oblique plane osteotomy, as described by Rab,24 corrects varus and rotation simultaneously and allows compression of flat bone surfaces (Figure 8). Procurvatum occurs at the osteotomy site but this is mild and should remodel in the younger child. A graduated correction using an external frame fixator may improve accuracy and reduce neurovascular complications. In a series of 22 tibiae in obese children, Feldman25 reported that using the Taylor Spatial Frame, 95% of cases were corrected to within 3 of desired angulation and all corrected within 5 mm of desired length. Patient obesity and leg shape present a challenge in frame construction and monitoring correction.
remaining open proximal physis and no further growth in the proximal tibia. In addition to elevating the medial hemiepiphysis, the surgical procedure also includes a lateral hemiepiphysiodesis and proximal fibular epiphysiodesis to prevent overgrowth.27 The mechanical alignment is further corrected with a second osteotomy in the subtuberosity region (Figure 9). These procedures may be performed synchronously or in a staged manner.28 A variety of methods to stabilize the correction have been used including plates, wires, plaster and ring fixators, which in unilateral cases may also allow correction of limb length discrepancy. Some authors have questioned the need for medial plateau elevation. Stantiski29 has shown that in a number of cases there are abnormally thick meniscal elements in the medial joint line filling the void between the medial femoral condyle and the ‘depressed’ plateau. In such cases a weight bearing knee radiograph will differentiate this from cases where there is deficient non-osseous support. Barakat and Monsell30 have described a surgical technique for adolescent Blount’s using an arthrogram to identify deficient non-osseous medial support. A medial plateau elevating osteotomy was then performed, as necessary. A second osteotomy was then required to address the posterior slope, rotation and shortening. A gradual correction of the multiplanar deformity was achieved using the Taylor Spatial Frame. In the presence of distal femoral varus, a lateral femoral ‘8 plate’ was applied and a proximal tibial and fibular epiphysiodesis performed to prevent any recurrence.
Double osteotomy: the so called ‘double elevating osteotomy’ aims to elevate the medial hemiepiphysis and simultaneously correct varus.6,26 The medial plateau hemiepiphyseal elevation osteotomy is typically used where there is significant depression of the medial plateau with considerable medial epiphyseal slope. It is a definitive procedure that can only be done as the child nears adolescence since there will be a surgical closure of the
Figure 7 A single osteotomy (lateral closing wedge) is performed at skeletal maturity for adolescent Blount’s, and fixed with a lateral locking plate.
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Figure 8 Pre- and post-operative radiographs of the Oblique Plane Osteotomy simultaneously correcting varus and internal rotation, as described by Rab.24
Figure 9 A double elevating osteotomy that has been used to elevate the medial hemiepiphysis, and a separate osteotomy below the tibial tuberosity to address the rotational and mechanical axis. The fibula has been osteotomized and the struts used as grafts to support the articular elevation. A proximal fibular physiodesis has been performed and the lateral hemiepiphysiodesis staples have been retained.
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The affected tibia was overlengthened in unilateral cases to produce equal leg lengths at skeletal maturity. €ld31 advocated resection of a bony bar in those with Langeskio considerable growth remaining. However, given the angular deformity already present it is unlikely that physiolysis will be the only procedure required for these patients. The bony bar represents an end-stage in medial physeal ‘failure’, as such growth following resection will not be normal. It is recommended that bar resection is contraindicated if the bony bridge exceeds 50% of the physeal width. In a series of 27 tibiae between the ages of 5 and 10, Andrade and Johnston32 found good results if bar resection was combined with a valgus osteotomy in those under the age of 7 years. This, however, has not been reported by other authors. Additional osteotomies that correct femoral deformities are also described. These include osteotomies of the distal femur to correct varus in adolescent Blount’s or correction of the distal femoral valgus in infantile Blount’s, to restore the coronal alignment of the joint line. Femoral rotational osteotomies in cases of excessive anteversion may also be used.
pathogenesis and best operative treatment strategies for this condition is required. A
REFERENCES 1 Salenius P, Vankka E. The development of the tibiofemoral angle in children. J Bone Joint Surg Am 1975; 57: 259e61. 2 Blount WP. Tibia vara: osteochondrosis deformans tibiae. J Bone Joint Surg 1937; 19: 1e29. 3 Levine AM, Drennan JC. Physiological bowing and tibia vara. The metaphyseal-diaphyseal angle in the measurement of bowing deformities. J Bone Joint Surg Am 1982; 64: 1158e63. 4 Feldman DS, Madan SS, Koval KJ, van Bosse HJ, Bazzi J, Lehman WB. Correction of tibia vara with six-axis deformity analysis and the Taylor Spatial Frame. J Pediatr Orthop 2003; 23: 387e91. 5 Mitchell EI, Chung SMK, Dask MM, Greg JR. A new radiographic grading system for Blount’s disease. Orthop Rev 1980; 9: 27e33. € ld A. Tibia vara: osteochondrosis deformans tibiae. 6 Langeskio Blount’s disease. Clin Orthop Relat Res 1981; 158: 77e82. € ld classification of 7 Stricker SJ, Edwards PM, Tidwell MA. Langeskio tibia vara: an assessment of interobserver variability. J Pediatr Orthop 1994; 14: 152e5. 8 Loder RT, Johnston 2nd CE. Infantile tibia vara. J Pediatr Orthop 1987; 7: 639e46. 9 Sabharwal S. Blount disease. J Bone Joint Surg [Am] 2009; 91: 1758e76. 10 Sevastikoglou JA, Eriksson I. Familial infantile osteochondrosis deformans tibiae. Idiopathic tibia vara. A case report. Acta Orthop Scand 1967; 38: 81e7. 11 Cook SD, Lavernia CJ, Burke SW, Skinner HB, Haddad Jr RJ. A biomechanical analysis of the etiology of tibia vara. J Pediatr Orthop 1983; 3: 449e54. 12 Kline SC, Bostrum M, Griffin PP. Femoral varus: an important component in late-onset Blount’s disease. J Paediatr Orthop 1992; 12: 197e206. 13 Aird JJ, Hogg A, Rollinson P. Femoral torsion in patients with Blount’s disease: a previously unrecognised component. J Bone Joint Surg 2009; 91-B: 1388e93. 14 Gordon JE, Heidenreich FP, Carpenter CJ, Kelly-Hahn J, Schoenecker PL. Comprehensive treatment of late-onset tibia vara. J Bone Joint Surg Am 2005; 87-A: 1561e70. 15 The foot and leg: tibia vara. In: Tachdjian MO, ed. Pediatric orthopedics, vol. 4. Philadelphia: WB Saunders Co, 1990; 2835e2850. 16 Davids JR, Huskamp M, Bagley AM. A dynamic biomechanical analysis of the etiology of adolescent tibia vara. J Pediatr Orthop 1996; 16: 461e8. 17 Schoenecker PL, Rich MM. The lower extremity. In: Morrissy RT, Weinstein SL, eds. Lovell and Winter’s pediatric orthopaedics. 6th edn, vol. 2. Philadelphia: Lippincott Williams and Wilkins, 2006; 1174. 18 Zayer M. Osteoarthritis following Blount’s disease. Int Orthop 1980; 4: 63e6. 19 Richards BS, Katz DE, Sims JB. Effectiveness of brace treatment in early infantile Blount’s disease. J Pediatr Orthop 1998; 18: 374e80. 20 Raney EM, Topoleski TA, Yaghoubian R, Guidera KJ, Marshall JG. Orthotic treatment of infantile tibia vara. J Pediatr Orthop 1998; 18: 670e4. eda P, Urquhart B, Sullivan E, Haynes RJ. Hemiepiphysiodesis for 21 Castan the correction of angular deformity about the knee. J Pediatr Orthop 2008; 28: 188e91.
Prognosis The follow-up of all Blount’s cases requires regular review of rotation, length and alignment until skeletal maturity. Where significant limb length discrepancies remain in unilateral cases, epiphysiodesis of the longer tibia may be considered. Infantile Blount’s disease is recognized as a progressive phenomenon. The prognosis has been shown by Doyle23 in a 15-year follow-up study to be principally related to two factors: disease stage and age of the patient at surgical intervention. These factors are related, as advanced disease with bar formation is found in the older child. Patients who underwent a single €ld stage less than or osteotomy at an age less than 4 or Langeskio equal to III had a favourable outcome and reduced need for further surgery. Knee pain was less prevalent in those who had a single early intervention. The presence of medial growth plate arrest with a bony bar carries a poor prognosis. Other factors that are likely to increase recurrence rates are obesity, a steep medial physeal slope and failure to achieve an overcorrected valgus position after osteotomy.8 Adolescent Blount’s has a better prognosis owing to absence of physeal bars.17
Conclusion The diagnosis of Blount’s disease must be made through exclusion of physiological varus, and the other pathologic conditions that lead to varus deformity. Identification of typical radiological features, the stage of the disease process and the age of the child help in formulating a management plan. Early stage infantile Blount’s may respond to bracing but this is not indicated in those with advanced stage disease or in those with adolescent Blount’s. Surgical correction at an early stage, overcorrecting the alignment, may reduce the chance of disease progression and the adult sequelae of this condition. The end-stage of infantile disease is physeal failure resulting in bar formation. The bar must be identified and surgical correction of the deformity planned accordingly, as deformity will recur if the lateral physis is left open. Osteotomies should correct coronal, sagittal and axial alignment deformities and sloping of the medial hemiepiphysis can also be corrected. Further investigation into the
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22 The tibia. In: Morrissey RT, ed. Atlas of pediatric orthopaedic surgery. 2nd edn. Lippincott Raven, 1996; 573e606. Chapter 6. 23 Doyle BS, Volk AG, Smith CF. Infantile Blount disease: long-term follow-up of surgically treated patients at skeletal maturity. J Pediatr Orthop 1996; 16: 469e76. 24 Rab GT. Oblique tibial osteotomy for Blount’s disease (tibia vara). J Paediatr Orthop 1988; 8: 715. 25 Feldman MD, Schoenecker PL. Use of the metaphyseal-diaphyseal angle in the evaluation of bowed legs. J Bone Joint Surg [Am] 1993; 75: 1602e9. 26 Gregosiewicz A, Wosko I, Kandzierski G, Drabik Z. Double-elevating osteotomy of tibiae in the treatment of severe cases of Blount’s disease. J Paediatr Orthop 1989; 9: 178e81. 27 van Huyssteen AL, Hastings CJ, Olesak M, Hoffman EB. Double-elevating osteotomy for late-presenting infantile Blount’s disease: the importance
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29
30 31
32
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of concomitant lateral epiphysiodesis. J Bone Joint Surg Br 2005 May; 87(5): 710e5. Schoenecker PL, Meade WC, Pierron RR, Sheridan JJ, Capelli AM. Blount’s disease: a retrospective review and recommendations for treatment. J Pediatr Orthop 1985; 5: 181e6. Stanitski DE, Stanitski CL, Trumble S. Depression of the medial tibial plateau in early onset Blount disease: myth or reality? J Pediatr Orthop 1999; 19: 265e9. Barakat M, Monsell F. New surgical technique for the definitive treatment of Blount’s disease. J Bone Joint Surg Br 2009; 92-B(suppl III): 375e6. € ld A, Riska EB. Tibia vara (osteochondrosis deformans Langenskio tibiae): a survey of seventy-one cases. J Bone Joint Surg Am 1964; 46: 1405e20. Andrade N, Johnston CE. Medial epiphysiolysis in severe infantile tibia vara. J Pediatr Orthop 2006; 26: 652e8.
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CME SECTION
CME questions based on the Mini-Symposium on “Spinal Deformity” The following series of questions are based on the MiniSymposium on ‘‘Spinal Deformity”. Please read the articles in the Mini-Symposium carefully and then complete the self-assessment questionnaire by filling in the square corresponding to your response to each multiple-choice question. After completing the questionnaire, either post or fax the answer page to the Orthopaedics and Trauma Editorial Office at the address at the bottom of the RESPONSE sheet. Please photocopy this page if you wish to keep your copy of Orthopaedics and Trauma. Replies received before the next issue of the journal is published will be marked and those reaching an adequate standard will qualify for three external CME points. You will be notified of your marks and a CME certificate will be despatched, via email, for your records.
D Trauma E Tumour 5 Which of the following tissues or organs is not mesodermal in origin? A Dermis B Haemopoietic tissue C Kidneys D Spinal cord E Vertebral column 6 Into what does Von Ebners fissure develop? A Atlantooccipital joint B Facet joints C Intervertebral disc D Spinal canal E Uncovertebral joint
Questions 1 Coronal shift in the spine is assessed by dropping a vertical line from which spinous process, thereafter observing where this line passes in relation to the natal cleft? A C1 B C7 C T1 D T12 E L1
7 Which of the following leads to the most rapid progression of an associated spinal curvature? A Incarcerated hemivertebra at L1 B Single semisegmented vertebra C Unsegmented bar at T5/6 with ipsilateral rib fusions D Unsegmented bar at T12/L1 with contralateral fully segmented hemivertebra E Wedge vertebra
2 Why is the PA view preferred in the assessment and monitoring of spinal deformity? A It gives better definition of vertebral bony anatomy B It places the right side of the spine to the right side of the image C It reduces the radiation dose to sensitive organs D The measurement of angles in the spine is more accurate on a PA view E There is less magnification of the spinal column
8 What is the sex ratio for the incidence of adult degenerative scoliosis? A 10 females:1 male B 3 females:1 male C 1:1 D 3 males:1 female E 10 males:1 female 9 Which of the following factors is not related to curve progression in adult degenerative scoliosis? A Age >70 B Cobb angle >30 C Intercrest line through L5 D Lateral olisthesis of >6 mm E Osteopaenia
3 Which of the following is not commonly part of the VACTERLS grouping? A Cerebral palsy B Duplex kidney C Horseshoe kidney D Radial dysplasia E Ventricular septal defect
10 Which of the following can be associated with an extreme lumbar kyphosis? A Congenital myopathies B Friedrich’s ataxia C Myelomeningocoele D Neurofibromatosis E Spastic cerebral palsy
4 Which of the following is the most common reason for the development of structural scoliotic deformity in children and teenagers, accepting that other aetiological factors may be even more frequent? A Congenital B Infection C Neuromuscular
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11 Assuming equal curve size and rate of progression, in which of the following patients is corrective spinal surgery likely to be carried out at the youngest age? A Duchenne muscular dystrophy B Myelomeningocoele C Neurofibromatosis D Spastic cerebral palsy E Spinal muscular atrophy
3 4 5 6 7 8 9 10 11 12
12 What is the expected degree of blood loss during instrumented spinal arthrodesis to correct a neuromuscular scoliosis? A 10% of the total blood volume of the child B 20% of the total blood volume of the child C 33% of the total blood volume of the child D 50% of the total blood volume of the child E 100% of the total blood volume of the child
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D D D D D D D D D D
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E E E E E E E E E E
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Your details (Print clearly) NAME....................... ADDRESS.................... .........................
Please fill in your answers to the CME questionnaire above in the response section provided to the right. A return address and fax number is given below the response section.
EMAIL...................... RETURN THE COMPLETED RESPONSE FORM by fax to þ44-113-392-3290, or by post to CME, Orthopaedics and Trauma, Academic Department of Orthopaedic Surgery, “A” Floor Clarendon Wing, Leeds General Infirmary, Great George Street, Leeds LS1 3EX, UK.
Responses Please shade in the square for the correct answer. 1A,B,C,D,E, 2A,B,C,D,E,
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A A A A A A A A A A
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CME SECTION
Answers to CME questions based on the Mini-Symposium on “Foot and Ankle” Please find below the answers to the Orthopaedics and Trauma CME questions from Vol. 25, issue 4 which were based on the Mini-Symposium on “Foot and Ankle”
Answers 1 2 3 4 5 6 7 8 9 10 11 12
A A A A A A A A A A A A
B B B B B B B B B B B B
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C C C C C C C C C C C C
D D D D D D D D D D D D
E E E E E E E E E E E E
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BOOK REVIEWS
Smart surgeons e smart decisions
techniques to revision techniques for reconstruction in the presence of acetabular and femoral bone loss including total femoral replacement. The descriptions of surgical approaches, techniques and extensile exposures for revision hip and knee surgery are excellent. Included are the extended trochanteric osteotomy and tibial tubercle osteotomy and these are accompanied by operative photographs and bespoke illustrations making visualization of the techniques much easier for the reader. The hip preservation section includes chapters on periacetabular osteotomy, femoral osteotomy and femoroacetabular impingement. The hip arthroscopy section is brief, however, and the limited scope means that further reading would be needed if this was of particular interest. Each chapter starts with an introduction to the topic to be covered, often including relevant anatomy, pathogenesis, suitable investigations and treatment options. However this book is primarily concerned with conveying operative technique and does not pretend to be a comprehensive orthopaedic text. At the end of each chapter there is a ‘Pearls and Pitfalls’ summary that gives a useful quick reference point. Overall this is an excellent, practical, well illustrated book primarily aimed at orthopaedic trainees and fellows but would be of interest to any orthopaedic surgeon with an interest in adult hip and knee reconstructive surgery. As such it deserves a place in any personal or departmental orthopaedic library. A
Uttam Shiralkar, ed. TFM Publishing Ltd, Nov 2010, ISBN 978-1-90337881-6, Price: £27.50,140 pages
Most books reviewed in this journal are textbooks that can be dipped into in order to find a specific piece of information, or to help understand a particular problem. This one is written in a narrative style, however, and really needs to be read through from cover to cover in order to comprehend the developing arguments and explanations. The topic is the psychology of decision making across all surgical specialities, so no a priori knowledge of the relevant theories is assumed. It is, however, easy to read and fulfils its own purpose by encouraging the reader to reflect on their own style and to question their own behaviours. It begins by reviewing the recent introduction of the WHO checklist and I was concerned that we were heading to a recommendation of protocol- and guideline-driven practice. However, after highlighting the enormous benefits that rigorous team functioning can bring to patient safety there is a deeper review of decision making psychology with illustrations not only from aviation, but also from the military and fire services, brought to life by regular clinical vignettes to root the message in medical practice. Moving on, therefore, we look at intuitive thinking and how this can be developed, such that one is left with much to think about. I don’t know if the bad decision makers could be made better by digesting this work e the earlier chapters suggest that they might be the ones least likely to benefit. However, those looking for self-improvement will come away with much to contemplate. It isn’t a book that will help prepare trainees for any exam they are currently likely to encounter in their professional careers, but is a book that I could recommend anyone to read, whatever their career stage. A
Chris Brew MD FRCS(Tr & Orth) Consultant Orthopaedic Surgeon, Orthopaedic Centre, Chapel Allerton Hospital, Harehills Lane, Leeds LS7 4SA, UK.
Operative techniques in pediatric orthopaedics David Limb
John M Flynn, Sam W Wiesel, Publisher: Lippincott Williams and Wilkins; ISBN: 9781451102635, Pages: 784; Price: £164
FRCS(Ed)Orth
Consultant Orthopaedic Surgeon, Orthopaedic Department, Chapel Allerton Hospital, Leeds LS7 4SA, UK.
Operative Techniques in Pediatric Orthopaedics is one of a series covering all the orthopaedic sub-specialities. It is an atlas of operative surgery but also has background information on the conditions covered. It is a comprehensive book covering both elective and trauma paediatric surgery. It also has descriptions of certain procedures, for example psoas lengthening at the pelvic brim, which I have not been able to find good, well illustrated, descriptions of previously. Each chapter is titled with the operative procedure eg Pericapsular osteotomies of Pemberton and Dega, but includes subsections on Anatomy, Pathogenesis, Natural History, Patient History, Imaging and Non-operative management before commencing on the description of the surgical procedures. These are clearly and concisely described with excellent illustrations, both operative photographs and diagrams. In this respect it is as least as good as the atlas accompanying Lovell but with use of modern colour publishing techniques has added a great deal more. My only criticism of the book (except that the letter ‘N’ has been left out of the index) concerns its attempt to be
Operative techniques in Adult Reconstruction Surgery J Parvizi, R Rothman, S Wiesel, eds. Lippincott 2011; ISBN: 97814511 02628, Pages: 336; Price: £95
Operative Techniques in Adult Reconstruction Surgery is one of a series of seven operative techniques books. It is divided into three sections, Hip Reconstruction, Hip Preservation and Knee Reconstruction. There are 30 chapters, to which 59 international authors have contributed, although the majority are from North America. It is briefcase-sized and therefore easily portable, but if you forget your book there is a full online version that is made available to the reader once registered on a website using an access code provided with the book. The hip and knee reconstruction sections cover everything from routine primary cemented and uncemented arthroplasty
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BOOK REVIEWS
comprehensive. This has advantages in that when you turn to a chapter all the information is immediately present. However for some conditions eg radial neck fractures it means that much information is replicated in related chapters. This is an excellent book which clearly describes techniques eg acetabular osteotomies that can be very hard to grasp and visualize. It would be of great use to a resident on a paediatric
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orthopaedic rotation or particularly to those undertaking Fellowships in the speciality. A
Joshua Bridgens
MBBS BSC FRCS
Consultant Orthopaedic Surgeon, Leeds Metropolitan University, Churchwood Avenue, Leeds LS6 3QS, UK
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