Increasing the Knee Arc of Motion in Patients With Arthrogryposis: Minimum 2-year Follow-up.

Background: Surgery for knee flexion contractures in patients with arthrogryposis multiplex congenital (AMC) have achieved extension to redirect the arc of motion and improve ambulation but has not demonstrated maintained increases in total range of motion (ROM). This study aimed to review the clinical outcomes of combined posterior knee release, proximal femoral shortening, and nerve decompression in patients with arthrogryposis.

Methods: A retrospective chart and radiographic review were performed on patients with AMC who underwent treatment for knee flexion deformities ≥30 degrees. ROM, ambulation status, and orthotic use were reviewed and analyzed. Complications were recorded.

Results: Twenty-nine patients with 51 knees and a mean age of 5.7 years were included. The mean follow-up was 36.9 months. The mean ROM increased from 49 to 80 degrees between pre-op and latest follow-up (P<0.0001). The mean final follow-up flexion deformity was 10 degrees (P<0.0001). Preoperative ROM was moderately correlated with final ROM (rs=0.51). The percentage of ambulatory patients improved from 39% to 93%. Five limbs experienced a fracture either intraoperatively or postoperatively, and 5 limbs required a return trip to the operating room.

Conclusions: Improved ambulation and knee ROM can be maintained in patients with AMC at a minimum 2-year follow-up. Prospective investigation and longer follow-up are required to validate these findings.

Level of evidence: Level IV-therapeutic.