Femoral anterior distal hemiepiphysiodesis for correction of knee flexion contractures in arthrogryposis

Knee flexion contractures in children with arthrogryposis limit or prevent efficient ambulation. This study assesses the effectiveness of femoral anterior distal hemiepiphysiodesis (FADHE) to treat knee contractures. Over an 8-year period, 57 children with arthrogryposis underwent 90 FADHEs for knee flexion contractures. The mean age at surgery was 7.1 years. Knee range of motion data was recorded preoperatively, postoperatively, and at clinical follow-ups, as was ambulatory ability. The average follow-up was 4.2 years; 65 knees had concomitant posterior releases; eight knees were treated for recurrences after initial correction with distraction arthrodiastasis. The preoperative mean flexion contracture of 35° improved to 7° at hardware removal (<0.0001) an average 17.5 months after implantation, for a correction rate of 2.1°/month. Knees with contractures of less than or equal to 25° corrected well without a posterior release, and most knees with contractures between 30° and 55° corrected well with a concomitant posterior release. The 82 knees undergoing a FADHE as an initial procedure had a 75° mean total arc of motion preoperatively and 62° at final follow-up. The overall recurrence rate was 0.61°/month. Nine patients (14 knees) underwent repeat hemiepiphysiodesis for contracture recurrence at 39 months after plate removal. Sixteen of the 31 patients who were not independent ambulators preoperatively became so by final follow-up. In children with arthrogryposis, FADHE is an appropriate treatment for knee contractures less than or equal to 25°, and for contractures less than or equal to 55° with a concomitant posterior knee release. Recurrence of contracture is common but treatable. Knee-ankle-foot orthoses are essential to obtain and maintain soft tissue stretch. LEVEL OF EVIDENCE: Therapeutic Level IV.