Distal femoral extension osteotomy for knee flexion contracture in patients with arthrogryposis.

Severe knee flexion contractures in patients with arthrogryposis multiplex congenita were treated by distal femoral extension osteotomy. Thirty-two operations were followed for an average of 32 months. Contractures were corrected from 49 degrees to 6 degrees. During follow-up there was a loss of correction of 22 degrees at a rate of 0.9 degrees/ month. The angle of the distal femoral physis and the shaft of the femur was 2 degrees of flexion preoperatively, and postoperatively it measured 43 degrees of extension and at late follow-up it measured 19 degrees. Remodeling occurred at a rate of 1.0 degrees/month, which correlated with recurrence. All patients increased their ambulatory ability at least one level. There was one wound infection. Distal femoral extension osteotomy is effective and safe for the correction of knee flexion contracture. Recurrence occurs in all growing children.