Osteochondral Lesions of the Talar Dome

ORTHOPAEDIC SURGERY BOARD REVIEW MANUAL PUBLISHING STAFF PRESIDENT, GROUP PUBLISHER Bruce M. White EXECUTIVE EDITOR Debra Dreger SENIOR EDITOR Becky Krumm, ELS CONTRIBUTING EDITOR Robert Litchkofski ASSISTANT EDITOR Jennifer M. Vander Bush EDITORIAL ASSISTANTS Renee Autumn Ray A.C. Arkles EXECUTIVE VICE PRESIDENT Barbara T. White, MBA PRODUCTION DIRECTOR Suzanne S. Banish PRODUCTION ASSOCIATES Tish Berchtold Klus Christie Grams Mary Beth Cunney ADVERTISING/PROJECT MANAGER Patricia Payne Castle NOTE FROM THE PUBLISHER: This publication has been developed without involvement of or review by the American Board of Orthopaedic Surgery. Endorsed by the Association for Hospital Medical Education The Association for Hospital Medical Education endorses HOSPITAL PHYSICIAN for the purpose of presenting the latest developments in medical education as they affect residency programs and clinical hospital practice. Osteochondral Lesions of the Talar Dome Series Editor: Robert T. Trousdale, MD Associate Professor of Orthopaedic Surgery, Mayo Graduate School of Medicine, Consultant, Department of Orthopaedic Surgery, Mayo Clinic, Rochester, MN Contributing Authors: Diane L. Dahm, MD Associate Professor of Orthopaedic Surgery, Mayo Graduate School of Medicine, Consultant, Department of Orthopaedic Surgery, Mayo Clinic, Rochester, MN James Manzanares, MD Fellow in Pediatric Orthopaedics, Nemours Children s Clinic, Jacksonville, FL Table of Contents Introduction.............................. 2 Anatomy of the Talus........................ 2 Etiology.................................. 2 Epidemiology.............................. 3 Evaluation................................ 3 Classification.............................. 6 Treatment Options.......................... 7 Recent Advances in Operative Management..... 10 Summary................................ 10 References............................ 11 Cover Illustration by Marc Galindo Copyright 2001, Turner White Communications, Inc., 125 Strafford Avenue, Suite 220, Wayne, PA 19087-3391, www.turner-white.com. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, mechanical, electronic, photocopying, recording, or otherwise, without the prior written permission of Turner White Communications, Inc. The editors are solely responsible for selecting content. Although the editors take great care to ensure accuracy, Turner White Communications, Inc., will not be liable for any errors of omission or inaccuracies in this publication. Opinions expressed are those of the authors and do not necessarily reflect those of Turner White Communications, Inc. Orthopaedic Surgery Volume 7, Part 2 1

ORTHOPAEDIC SURGERY BOARD REVIEW MANUAL Osteochondral Lesions of the Talar Dome Series Editor: Robert T. Trousdale, MD Contributing Authors: Diane L. Dahm, MD James Manzanares, MD I. INTRODUCTION Osteochondral lesions of the talar dome are a relatively common cause of ankle pain and disability, and they are often missed in the routine evaluation following ankle injury. Alexander Munro was the first person to describe osteochondral loose bodies of the ankle joint in 1956. 1 Since that time, terminology used in describing these lesions has included osteochondral fracture, which implies traumatic origin, and osteochondritis dissecans, which generally implies ischemic origin. For the purposes of this review, the term osteochondral lesion will be used to describe any acute or chronic injury involving the articular surface of the talar dome. II. ANATOMY OF THE TALUS A. The talus has 3 parts: the body, neck, and head. B. 60% of the talus is covered by articular cartilage. C. The superior surface of the talar body is wider anteriorly than posteriorly and articulates with the distal surface of the tibia. Otherwise known as the talar dome, the superior surface of the talar body is the most common site for osteochondral lesions in the ankle joint. D. Blood supply (Figure 1) 1. The posterior tibial artery gives rise to the artery of the tarsal canal, and this artery provides the main blood supply to the talar body, supplying one half to two thirds of the body s middle section. 2. The deltoid branches of the posterior tibial artery supply the medial one third of the talar body. 3. Branches of the artery of the sinus tarsi supply the lateral one eighth to one quarter of the talar body. III. ETIOLOGY A. Ischemia 1. Ischemic necrosis of subchondral bone may lead to separation of an osteochondral fragment. 2 2. Environmental factors such as alcohol abuse and steroid use as well as hereditary and endocrine factors may play a role in the development of lesions in the absence of trauma. 3. Ischemic etiology is thought to be more common in medial talar dome lesions. 3 B. Trauma 1. Isolated incidents of macrotrauma or cumulative microtrauma are now thought to be responsible for most osteochondral talar dome lesions. In a review of more than 500 osteochondral talar dome lesions, Flick and Gould found that 98% of lateral lesions and 70% of 2 Hospital Physician Board Review Manual

Medial Deltoid branches Anterior Posterior tubercle vessels Posterior Superior neck vessels Superior neck vessels Artery of tarsal canal Artery of tarsal sinus Artery of tarsal canal Lateral Superior neck vessels Figure 1. Internal vascularity of the talus. Superior view (top), sagittal section through the midtalus (bottom left), and coronal section through the talar neck (bottom right). (Adapted with permission from Gelberman RH, Mortensen WW. The arterial anatomy of the talus. Foot Ankle 1983;4:64 72.) Medial Artery of tarsal sinus Posterior tubercle vessels Artery of tarsal sinus Lateral medial lesions were associated with a history of trauma. 4 2. Lateral lesions. These lesions are generally thought to be true osteochondral fractures and are almost always associated with an acute traumatic episode. 4 The mechanism of injury in lateral lesions is generally an inversion force to a dorsiflexed foot with internal rotation of the tibia, causing impaction of the talus against the articular surface of the fibula. 5 3. Medial lesions. These may be traumatic or atraumatic in origin. The mechanism of injury typically is a force through a plantar flexed foot with external rotation at the tibia, causing impaction of the articular surface of the tibia against the superomedial ridge of the talus. 4 IV. EPIDEMIOLOGY A. Osteochondral lesions of the talus account for 0.09% of all fractures and 1% of all talus fractures. 4 B. The average age of patients presenting with osteochondral lesions is 20 to 30 years. There is a slight male predominance. 6 C. Approximately 10% of osteochondral talar dome lesions are bilateral. D. Osteochondral lesions of the talus occur at a rate of 6.5 per 100 ankle sprains. 7 E. Medial lesions are more common than lateral lesions. They are typically located at the posteromedial talar dome and are typically deep and cupshaped. F. Lateral lesions are more commonly associated with trauma. They tend to be shallower than medial lesions and are typically located in the anterolateral aspect of the talar dome; however, they occasionally occur posteriorly. V. EVALUATION A. An algorithm of an approach to evaluation of suspected talar dome lesions is shown in Figure 2. B. Clinical presentation 1. Patients often present with history of inversion injury to the ankle or ankle sprain. 2. Symptoms may be intermittent, vague, and increased with weight bearing. 3. Chronic symptoms of stiffness, swelling, catching, clicking, locking, and giving way may occur. C. Physical examination 1. Examination may reveal localized tenderness, decreased range of motion, crepitus, and swelling, although no signs are pathognomonic for osteochondral talar dome lesions. 2. Lateral lesions are painful with direct palpation, particularly with the ankle held in plantar flexion. Orthopaedic Surgery Volume 7, Part 2 3

Careful history and physical examination Acute ankle injury Chronic ankle pain Plain radiographs Plain radiographs Negative Positive (ie, OCL present) Negative Positive (ie, OCL present) Continued symptoms 2 to 4 weeks following routine management CT scan MRI, consider arthroscopic evaluation CT scan, consider arthroscopic evaluation Bone scan Negative Positive (ie, OCL present) Continue symptomatic management Further evaluation with CT or MRI Figure 2. Evaluation for suspected talar dome lesions. CT = computed tomography; MRI = magnetic resonance imaging; OCL = osteochondral lesion. 3. With medial lesions, there may be tenderness anteriorly with the ankle in plantar flexion or posteromedially with the ankle in dorsiflexion. 4. Lateral ligamentous laxity may coexist with osteochondral talar dome lesions. D. Imaging 1. Plain radiographs (Figure 3) a. Anteroposterior, lateral, and mortise views of the symptomatic and asymptomatic opposite ankle should be performed. 1) Anteroposterior and mortise views in both plantar and dorsiflexion may increase the sensitivity of the radiograph examination. 2) Anteroposterior radiograph in plantar flexion may increase visualization of the medial talar dome. 3) Mortise view in dorsiflexion may increase visualization of the lateral talar dome. b. Stress radiographs should be considered if ligamentous laxity is suspected. 2. Technetium-99m bone scan a. Increased uptake in the area of a talar dome lesion is demonstrated; hyperemia is present in the blood pool phase. b. Sensitivity increases if the scan is performed after 48 hours from injury. c. Bone scan is often used in the subacute setting when plain radiographs are negative. d. Because bone scan has low specificity, further investigation with computed tomography (CT) or magnetic resonance imaging (MRI) is generally warranted. 3. Computed tomography scan (Figure 4) a. CT is the most effective method for evaluating the osseous anatomy of talar dome lesions. b. Coronal and axial views should be obtained. 4 Hospital Physician Board Review Manual

Figure 3. Lateral and anteroposterior radiographs of a medial talar dome lesion. Figure 4. Medial osteochondral talar dome lesion on computed tomography scan. 4. Magnetic resonance imaging (Figure 5) a. MRI is most sensitive for detecting early nondisplaced lesions. b. It provides detail sufficient to image other lesions that may be responsible for the patient s symptoms, such as tendon and ligament injury or soft tissue impingement lesions. E. Arthroscopy (Figure 6) 1. This procedure is the most reliable method for determining the status of the articular cartilage and the degree of displacement of the osteochondral talar dome lesion. 2. It allows for definitive diagnosis and treatment in most cases of osteochondral talar dome lesions refractory to nonoperative management. Orthopaedic Surgery Volume 7, Part 2 5

Figure 5. Magnetic resonance image of a medial osteochondral talar dome lesion. Figure 6. Arthroscopic view of a partially detached osteochondral talar dome lesion. VI. CLASSIFICATION I. Compression II. Partial fracture nondisplaced III. Complete fracture: nondisplaced IV. Displaced fracture Figure 7. Berndt and Harty staging system for osteochondral lesions of the talar dome. A. Radiographic (Berndt and Harty) 5 (Figure 7) 1. Stage I: small subchondral compression fracture 2. Stage II: partial avulsion of a fragment 3. Stage III: complete avulsion of a fragment without displacement 4. Stage IV: avulsed fragment displaced within the joint B. Computed tomography classification (Ferkel) 8 1. Stage I: cystic lesion within the dome of the talus, intact roof on all views 2. Stage IIA: cystic lesion with communication to talar dome surface 3. Stage IIB: open articular surface lesion with overlying undisplaced fragment 4. Stage III: undisplaced lesion with lucency 5. Stage IV: displaced fragment C. Magnetic resonance imaging classification (Anderson) 9 1. Stage I: subchondral trabecular compression; plain radiographs normal but positive bone scan, marrow edema on MRI 2. Stage IIA: formation of subchondral cyst 3. Stage IIB: incomplete separation of fragment 4. Stage III: unattached, undisplaced fragment with presence of synovial fluid around fragment 5. Stage IV: displaced fragment D. Arthroscopic classification 1. Ferkel classification 10 6 Hospital Physician Board Review Manual

Table 1. Staging System for Classifying Osteochondral Lesions of the Talus Magnetic Radiographic Stage Arthroscopic Resonance Imaging (Berndt and Harty) I Irregularity and softening of articular Thickening of articular cartilage Compression lesion, no visible cartilage, no definable fragment and low signal changes fragment II Articular cartilage breached, definable Articular cartilage breached, low Fragment attached fragment, not displaceable signal rim behind fragment indicating fibrous attachment III Articular cartilage breached, definable Articular cartilage breached, Nondisplaced fragment without fragment, displaceable but attached high signal changes behind attachment by some overlying articular cartilage fragment indicating synovial fluid between fragment and underlying subchondral bone IV Loose body Loose body Displaced fragment Reprinted with permission from Dipaola JD, Nelson DW, Colville MR. Characterizing osteochondral lesions by magnetic resonance imaging. Arthroscopy 1991;7:101 4. a. Grade A: smooth, intact but soft or ballottable b. Grade B: rough surface c. Grade C: fibrillations and fissures d. Grade D: flap present or bone exposed e. Grade E: loose undisplaced fragment f. Grade F: displaced fragment 2. Pritsch classification 11 a. Stage I: intact, firm, shiny cartilage b. Stage II: intact, soft cartilage c. Stage III: frayed cartilage E. Utility of the classification schemes 1. The Berndt and Harty classification is most commonly used when discussing treatment and outcome and is the classification used throughout the remainder of this manual. However, it does not take into account inspection of the lesion at surgery, which allows for definitive determination of articular cartilage integrity. 2. Dipaola et al have proposed a staging system for classifying osteochondral talar dome lesions that incorporates arthroscopic, MRI, and radiographic evaluation (Table 1). 12 Use of a combined staging system such as this likely allows for the most accurate representation of talar dome pathology. VII. TREATMENT OPTIONS A. General 1. Indications for treatment of osteochondral talar dome lesions are somewhat controversial. 2. Generally, treatment should be based on patient symptoms, taking into account size, location, displacement, and chronicity of the lesion, as well as patient age. 3. Radiographic appearance does not necessarily correlate with clinical outcome following treatment. 6 4. No long-term natural history studies exist for untreated osteochondral talar dome lesions. B. Nonoperative management 1. This approach consists of cast or brace immobilization and protected weight bearing for 6 to 12 weeks, followed by increasing pain-free range of motion exercises and strengthening along with proprioceptive training. 2. A nonoperative approach is indicated for initial management of stage I and II lateral and medial lesions and stage III medial lesions. 13,14 3. Most authors agree that delay in operative treatment resulting from a trial of nonoperative therapy does not adversely affect the results of later surgical management. Orthopaedic Surgery Volume 7, Part 2 7

However, Pettine and Morrey 13 found that delaying surgery beyond 1 year had an adverse effect on outcome. 3,4,13,15 C. Operative management 1. General indications a. Symptomatic lateral stage III lesions and medial stage III lesions that have failed a trial of nonoperative management b. Acute or chronic symptomatic stage IV (completely displaced) lesions c. Stage III and IV lesions occurring concomitantly with ankle fractures requiring open reduction and internal fixation d. Recently, surgical treatment has been advocated for all symptomatic MRI and CT stage III and IV lesions. 6 2. General surgical techniques a. Open ankle arthrotomy has traditionally been performed for excision of loose bodies, joint debridement, and drilling or abrasion at the site of the osteochondral talar dome lesion. b. Distal tibial articular surface grooving and medial or lateral malleolar osteotomy have been used to increase exposure, particularly for more posteriorly located lesions. c. Ankle arthroscopy has emerged as an important tool for both diagnosis and treatment of osteochondral talar dome lesions. 1) A 2.7-mm small- joint arthroscope is typically used in combination with noninvasive distraction techniques. 2) Arthroscopy allows for excellent visualization of the entire joint surface and results in less morbidity compared with open approaches. 3) It may be used alone or in combination with percutaneous or open approaches. 3. Specific methods a. Internal fixation of osteochondral talar dome lesions 1) Indication. This method is indicated in younger patients with acute traumatic lesions greater than or equal to 1 cm in diameter. 3 2) The fragment should have adequate attached subchondral bone. 3) Approach a) Internal fixation of posteromedial lesions generally requires a medial malleolar osteotomy for optimal exposure. b) Internal fixation of anterolateral lesions may be performed via open anterolateral arthrotomy or arthroscopically assisted percutaneous techniques. 4) Methods of internal fixation a) Kirschner wires i) Technique. Wires may be placed retrograde through the sinus tarsi or using a transmalleolar approach. ii) Advantage. Arthrotomy is typically not required. iii) Disadvantages. Wires must be removed and do not allow for compression. b) Small compression screws (ie, Herbert screws or similar) i) Technique. Open arthrotomy with or without medial malleolar osteotomy is required. ii) Advantage. Compression may be achieved. iii) Disadvantage. Screws must be removed. c) Bioabsorbable pins i) Technique. Open arthrotomy with or without medial malleolar osteotomy. ii) Advantage. Pin removal is not required. iii) Disadvantages. Compression cannot be achieved, and there is a theoretical risk of local reaction or bone resorption with degradation of bioabsorbable implants. b. Drilling 1) Indication. Drilling is indicated when there are nondisplaced lesions with intact overlying articular cartilage. Theoretically, drilling increases vascularization and healing of the osteochondral fragment. 2) Approach. Medial lesions may be drilled using an antegrade transmalleolar technique or retrograde technique through the sinus tarsi under 8 Hospital Physician Board Review Manual

arthroscopic guidance. Lateral lesions are typically accessible for drilling via the anterolateral portal or an accessory lateral portal. 3) Technique. The general technique involves perforating the lesion with multiple drill holes; a small Kirschner wire (0.062 in) is typically used. c. Bone grafting 1) Indications. Bone grafting is indicated for partially detached lesions with intact articular surface and large subchondral cyst formation. 2) Approach. Transmalleolar and retrograde transtalar approaches have been described. 16,17 3) Technique. The involved bone is curetted beneath the articular surface and autogenous cancellous or corticocancellous bone grafting is performed. d. Osteochondral fragment excision and debridement 1) Indications. Excision and debridement is indicated for small acute symptomatic lesions or chronic detached osteochondral lesions. 2) Approach. Excision/debridement may be performed open or arthroscopically. 3) Technique. The loose fragment is excised and then debridement of the bony bed is performed using curettage, burr, drilling, or microfracture. a) In theory, penetration of subchondral bone disrupts subchondral blood vessels and encourages formation of fibrocartilaginous repair tissue at the articular surface. 18 b) Long-term results of drilling appear to be superior to results of abrasion. 19 4. Postoperative management. This should be tailored to the individual patient but in general consists of 6 weeks of no weight bearing, early range of motion, and progression of rehabilitation, including strengthening, proprioceptive training, and plyometric activities. 5. Treatment of combined osteochondral talar dome lesions and lateral ligament instability a. When an acute osteochondral fracture and lateral ligament instability occur together, surgical treatment of the osteochondral lesion and nonsurgical treatment of the lateral ligament injury is indicated initially. Lateral ligament reconstruction is indicated only if instability symptoms persist. b. Chronic osteochondral talar dome lesions in association with chronic lateral ligamentous laxity should be treated in a staged manner if both are sufficiently symptomatic. 1) The osteochondral lesion is treated initially because early postoperative motion is generally required. 2) Reconstruction of the lateral ligament is performed as a staged second procedure because a significant period of postoperative immobilization is required. D. Results of operative management 1. Surgical treatment of stage III and IV lesions yields good early results in 63% to 88% of patients. 9,13 15 2. Patients may improve up to 18 to 24 months postoperatively. Long-term prognosis is still guarded, with symptoms and radiographic evidence of arthrosis often reported. 20 3. Prognostic factors a. Age. Patients younger than 25 years exhibit more improvement following surgery than those older than 25 years. 21 b. Stage of lesion 1) Van Buecken demonstrated that (Berndt and Harty) stage II and III lesions have excellent results more often than stage IV lesions. 22 2) Condition of the overlying cartilage (arthroscopic stage) may also affect prognosis; 11 however, evidence for this association is not conclusive. 20 c. Acuteness of the lesion. The best surgical results likely occur when there is a delay of less than 12 months from injury to treatment. 13,21 d. Prognostic factors relative to lesion location and patient activity level have not been conclusively defined. 4. Radiographic appearance of the osteochondral lesion at follow-up. The presence or absence of radiographic bony healing has not Orthopaedic Surgery Volume 7, Part 2 9

Figure 8. Osteochondral talar dome lesion treated with osteochondral autograft transfer from the ipsilateral knee. been found to correlate with clinical results in lesions treated conservatively or surgically. 5,20,22 5. Arthritis. Approximately 50% of patients can be expected to develop some evidence of degenerative arthritis regardless of the type of treatment. 14 VIII. RECENT ADVANCES IN OPERATIVE MANAGEMENT A. Osteochondral autograft transfer/mosaicplasty (Figure 8) 1. This technique involves osteochondral cylindrical graft harvest from the ipsilateral knee with transfer into the talar defect using specially designed tube chisels. 2. Excellent early results have been reported for displaced osteochondral talar dome lesions averaging 1 cm 2 in size. 23 However, concerns regarding long-term donor site morbidity remain. 24 B. Autologous chondrocyte implantation 1. This technique involves harvest of autologous chondrocytes and placement of cultured chondrocytes within the osteochondral talar defects in a 2-stage procedure. 25,26 2. Autologous chondrocyte transplantation has been studied extensively for lesions of the knee, and early results show some promise for the treatment of displaced osteochondral talar dome lesions. 25,27 C. Periosteal arthroplasty 1. This technique involves harvest of periosteum from the distal tibia and transplantation to the osteochondral talar dome defect in a single-stage procedure. 28 2. Early results hold promise for salvage treatment of symptomatic osteochondral talar dome lesions after failure of traditional techniques. IX. SUMMARY A. Osteochondral lesions of the talar dome are a relatively common cause of ankle pain and disability, and careful clinical and radiographic evaluation is required for accurate diagnosis in the patient presenting with pain following an ankle injury. B. Once the osteochondral talar dome lesion is identified, further imaging is typically required to determine the exact extent and location of the lesion and to plan appropriate treatment. C. Treatment should be based on patient symptoms, with specific attention to size, location, displacement, and chronicity of the lesion as well as patient age and activity level. D. A nonoperative approach is used to treat stage I and II medial and lateral lesions and stage III medial lesions initially; surgical treatment is reserved for those exhibiting persistent symptoms. 10 Hospital Physician Board Review Manual

E. Symptomatic lateral stage III lesions and all symptomatic stage IV lesions should be treated operatively for best results. F. Short-term results are generally satisfactory, but long-term prognosis is guarded. REFERENCES 1. Munro A. Microgeologie. Berlin: Thbillroth; 1956:236. 2. Campbell TJ, Ranawat CS. Osteochondritis dissecans: the question of etiology. J Trauma 1966;6:201 21. 3. Stone JW. Osteochondral lesions of the talar dome. J Am Acad Orthop Surg 1996;4:63 73. 4. Flick AB, Gould N. Osteochondritis dissecans of the talus (transchondral fractures of the talus): review of the literature and new surgical approach for medial dome lesions. Foot Ankle 1985;5:165 85. 5. Berndt AL, Harty M. Transchondral fractures (osteochondritis dissecans) of the talus. J Bone Joint Surg 1959; 41A:988 1020. 6. Ferkel RD. Arthroscopic treatment of osteochondral lesions, soft tissue impingement, and loose bodies. In: Pfeffer GB, editor. Chronic ankle pain in the athlete. Rosemont (IL): American Academy of Orthopaedic Surgeons; 2000;43 70. 7. Bosien WR, Stable OS, Russell SW. Residual disability following acute ankle sprain. J Bone Joint Surg 1955;37A: 1237 43. 8. Ferkel RD, Sgaglione NA, Del Pizzo W, et al. Arthroscopic treatment of osteochondral lesions of the talus: technique and results. Orthop Trans 1990;14:172 3. 9. Anderson IF, Crichton KJ, Grattan-Smith T, et al. Osteochondral fractures of the dome of the talus. J Bone Joint Surg Am 1989;71:1143 52. 10. Ferkel RD, Cheng MS, Applegate GR. A new method of radiologic and arthroscopic staging for osteochondral lesions of the talus [abstract]. Proceedings of the American Academy of Orthopaedic Surgeons 62nd Annual Meeting, Orlando (FL), 16 21 February 1995. Rosemont (IL): American Academy of Orthopaedic Surgeons; 1995:126. 11. Pritsch M, Horoshovski H, Farin I. Arthroscopic treatment of osteochondral lesions of the talus. J Bone Joint Surg Am 1986;68:862 5. 12. Dipaola JD, Nelson DW, Colville MR. Characterizing osteochondral lesions by magnetic resonance imaging. Arthroscopy 1991;7:101 4. 13. Pettine KA, Morrey BF. Osteochondral fractures of the talus. A long-term follow-up. J Bone Joint Surg Br 1987; 69:89 92. 14. Canale ST, Belding RH. Osteochondral lesions of the talus. J Bone Joint Surg Am 1980;62:97 102. 15. Alexander AH, Lichtman DM. Surgical treatment of transchondral talar-dome fractures (osteochondritis dissecans). Long-term follow-up. J Bone Joint Surg Am 1980; 62:646 52. 16. Guhl JF. Arthroscopic treatment of osteochondritis dissecans. Clin Orthop 1982;167:65 74. 17. Lahm A, Erggelet C, Steinwachs M, Reichelt A. Arthroscopic management of osteochondral lesions of the talus: results of drilling and usefulness of magnetic resonance imaging before and after treatment. Arthroscopy 2000; 16:299 304. 18. Kim HK, Moran ME, Salter RB. The potential for regeneration of articular cartilage in defects created by chondral shaving and subchondral abrasion. An experimental investigation in rabbits. J Bone Joint Surg Am 1991;73: 1301 15. 19. Frenkel SR, Menche DS, Blair B, et al. A comparison of abrasion burr arthroplasty and suchchondral drilling in the treatment of full thickness cartilage lesions in the rabbit. Trans Orthop Res Society 1994;19:483. 20. Shea MT, Manoli A 2nd. Osteochondral lesions of the talar dome. Foot Ankle 1993;14:48 55. 21. O Farrell TA, Costello BG. Osteochondritis dissecans of the talus. The late results of surgical treatment. J Bone Joint Surg Br 1982;64:494 7. 22. Van Buecken K, Barrack RL, Alexander AH, Ertl JP. Arthroscopic treatment of transchondral talar dome fractures. Am J Sports Med 1989;17:350 5. 23. Hangody L, Kish G, Karpati Z, et al. Treatment of osteochondritis dissecans of the talus: use of the mosaicplasty technique a preliminary report. Foot Ankle 1997; 18:628 34. 24. Simonian PT, Sussmann PS, Wickiewicz TL, et al. Contact pressures at osteochondral donor sites in the knee. Am J Sports Med 1998;26:491 4. 25. Giannini S, Vuda R, Vannini F. Autologous chondrocyte transplantation in osteochondral lesions of the ankle joint. Proceedings of the PanAmerican Congress on Medicine and Surgery of the Foot and Leg, Buenos Aires, Argentina, September, 2000. 26. Minas T, Peterson A. Chondrocyte transplantation. Oper Techn Orthop 1997;7:323. 27. Brittberg M, Lindahl A, Nilsson A, et al. Treatment of deep cartilage defects in the knee with autologous chondrocyte transplantation. N Engl J Med 1994;331:889 95. 28. Dechet T, Dahm DL, O Driscoll SW. Periosteal grafting for osteochondral lesions of the talar dome. Proceedings of the PanAmerican Congress on Medicine and Surgery of the Foot and Leg, Buenos Aires, Argentina, September, 2000. Orthopaedic Surgery Volume 7, Part 2 11

TOPICS COVERED IN THE ORTHOPAEDIC SURGERY BOARD REVIEW MANUALS Volume 5 Part 1 Part 2 Part 3 Part 4 Reflex Sympathetic Dystrophy; Knee Dislocations; Basic Science of Fracture Healing Hallux Valgus Deformity; Finger Replantation; Septic Arthritis Mensical Injuries; Rheumatoid Arthritis of the Hand and Wrist; Distal Humeral Fractures Pediatric Foot Deformities; Periprosthetic Hip and Knee Fractures Volume 6 Part 1 Part 2 Part 3 Part 4 Nonarthroplastic Treatment of Hip Dysplasia in Adults Primary Total Knee Arthroplasty Slipped Capital Femoral Epiphysis Fractures of the Femoral Diaphysis in Adults Volume 7 Part 1 Part 2 Total Hip Arthroplasty Osteochondral Lesions of the Talar Dome Copyright 2001 by Turner White Communications Inc., Wayne, PA. All rights reserved. 12 Hospital Physician Board Review Manual