Pagnani Fragment Osteochondritis Dissecans of the Femoral Condyles : Long-term Results of Excision of the

Nineteen patients with 20 osteochondritis dissecans lesions were evaluated between 2 and 20 years after excision of a partially detached (grade III) or loose (grade IV) fragment from the femoral condyles. Evaluation with the Hughston rating scale for osteochondritis dissecans revealed one excellent result, four good, four fair, six poor, and five failure results. Eleven patients had developed osteochondritis dissecans before skeletal maturity. In contrast to what has been stated in the literature, the results in these patients were no better than in those who developed osteochondritis dissecans as adults. The short-term results of excision are good, but the long-term results are extremely poor. Consequently, we recommend bone grafting and replacement of the fragment when it is technically possible because the long-term results are better than those after excision. Osteochondritis dissecans occurs secondary to an insult that causes avascular necrosis of the subchondral bone. If the fragment fails to revascularize, the bone resorbs, causing progressive deterioration of the fragment. The articular cartilage degenerates and eventually splits around the periphery of the lesion, allowing the fragment to be displaced into the joint. Excision of the fragment has been the most common method of treatment for osteochondritis dissecans when a loose or separated fragment exists.1,6, 7, 10,13-15 More recently, other treatment methods have been advocated, including removal of the fragment and drilling of the crater,’ replacement and stabilization of the fragment with internal fixation, 11,15 bone grafting 2, 10 and allograft replacement.9 The purpose of this study was to review our experience with excision of the fragment in patients with osteochondritis dissecans. MATERIALS AND METHODS Between 1973 and 1991 we treated 137 patients with osteochondritis dissecans of the knee. The diagnosis was made roentgenographically in all patients. Twenty-six of these patients with 27 lesions were treated by excision of the fragment. Seven patients were lost to followup. The remaining 19 patients with 20 lesions were evaluated 2 to 20 years after treatment. The average length of followup was 9 years. The lesion was excised in 3 knees with failure results after previous surgery and in 17 where the fragment was loose or deteriorated. There were 15 men and 4 women. The average duration of symptoms before excision of the fragment was 3.8 years. The original AP, lateral, and tunnel roentgenograms were used to classify the lesions by the anatomic and roentgenographic criteria of Cahill and Berg5 (Table 1). Sixteen of the lesions were on the medial femoral condyle and four were on the lateral femoral condyle (Fig. 1). The medial femoral condyle lesions ranged from 1.5 X 1 cm in diameter to 4 X 2.5 cm in diameter. The lateral femoral condylar lesions ranged from 2.5 X 2.5 cm in diameter to 3 x 4 cm in diameter. The stage of pathologic deterioration of the lesion was graded according to the criteria of Ewing and Voto. ’ Sixteen of the fragments were grade IV, or loose bodies, and four were grade III, or partially detached. The results were evaluated by the criteria of the International Knee Documentation Committee2 (IKDC) and the Hughston rating scale for osteochondritis dissecans.ll Clinical examination and AP, lateral, and tunnel roentgenograms were performed on each patient at followup. * Address correspondence and repnnt requests to Allen F Anderson, MD, The Lipscomb Clinic, Saint Thomas Medical Plaza, Suite 1000, 4230 Harding Road, Nashville, TN 37205 No author or related institution has received any financial benefit from research in this study © 1997 American Orthopaedic Society for Sports Medicine. All rights reserved. Not for commercial use or unauthorized distribution. by MICHAEL PAGNANI on January 31, 2008 http://ajs.sagepub. com Downloaded from