Novel Approach to Improving Knee Range of Motion in Arthrogryposis with a New Working Classification

Arthrogryposis multiplex congenita (AMC) is a rare condition defined as contrac-tures in multiple joints. Surgical interventions for severe knee flexion contractures have included posterior release, distraction and extension with external fixation and distal femoral extension osteotomies. These operations have been able to achieve knee extension, but not increase the range of motion. The purpose of this study was to review our experience with peroneal nerve decompression, posterior knee release and proximal femoral shortening. We retrospectively reviewed the medical charts and radiographs of all patients with a diagnosis of arthrogryposis who underwent aforementioned procedure. There were 39 patients with 73 knees included in the analysis with a mean follow-up of 21 months. The mean preoperative arc of motion was 45° and last followup arc of motion was 79° (p < 0.0001). The mean last followup flexion contracture was 8° (p < 0.0001). Additional subanalyses were performed on those with followup greater than 24 months and those with flexion contractures >60°; there were no differences found in these groups. This study demonstrates that it is possible to achieve a functional range of motion of the knees in patients with AMC while improving ambulatory function.