Restoration of the mechanical axis of the lower limb-a case report of perichondrium grafting of the medial femoral condyle

Abstract

A 21-year-old man had osteochondritis dissecans of the medial femoral condyle of the left knee. After twisting his leg a major fragment became loose in September 1990. The fragment was fixed with 6 Bio-fix pins. Postoperatively, the patient developed severe synovitis and the fragment as well as part of the medial femoral condyle became necrotic. Synovectomy and resection of the necrotic part of the condyle, performed in November 1990, were reported by Friden and Rydholm (1992). An infection could never be proved. There was a large cystic defect in the medial femoral condyle and weight-bearing radiographs showed joint reduction similar to gonarthrosis stage I of the medial femoro-tibial joint (Ahlback 1968) (Figure 1) with a deviation of the mechanical axis of 7 degrees in varus, compared to 1 degree in varus of the healthy side (Figure 2). The preoperative Lysholm score was 80 (Lysholm and Gillquist 1982) and the activity level was 4 (Tegnér and Lysholm 1985).