Does Open Reduction of Arthrogrypotic Hips Cause Stiffness?

Abstract

Concerns of potential hip stiffness following open reduction for congenitally dislocated hips in arthrogryposis multiplex congenita (arthrogryposis) persist, despite published accounts of positive outcomes. We retrospectively compared preoperative and postoperative hip motion and evaluated the ambulatory abilities of patients who underwent the procedure. Over a 10-year period, 52 patients with arthrogryposis had 75 open reductions for congenitally dislocated hips with a minimum follow-up of 2 years. The mean patient age at surgery was 23 months. Hip range of motion data was recorded preoperatively, postoperatively, and at last follow-up, as was ambulatory ability. Radiographs were assessed for hip station and avascular necrosis. The average follow-up was 68 months; 59% had concurrent femoral shortenings. Preoperatively, 34 hips had a mean flexion contracture of 33 degrees, improving 22 degrees at follow-up; 59 hips had <45 degree frogleg abduction and 39 hips had <30 degree abduction preoperatively, improving by 11 and 10 degrees, respectively (all P ≤0.001). The flexion-extension total arc of motion decreased by only 1 degree from preoperative to follow-up ( P =0.733). Patients with unilateral dislocation (n=29) had no significant difference in the total arc of motion between the dislocated and nondislocated hips at the final follow-up. Hips with <90 degrees of flexion preoperatively showed no improvement following reduction. At a mean follow-up of 68 months (24 to 152 mo), 31 patients were independently ambulatory, 15 were walker-dependent but still progressing, and 6 remained nonambulatory. Avascular necrosis (AVN) was seen in approximately half the hips but without affecting flexion-extension total arc of motion at follow-up; 55% of AVN cases were type 2, with only transient changes (delayed ossification). Open reduction for arthrogrypotic hip dislocations maintains mobility without causing stiffness. While pre-existing hip total arc of motion slightly worsened (∼1 to 5 degree), lower limb positioning improved, especially in hip extension and abduction, enhancing ambulation. Most achieved independent ambulation. Level IV-case series.