The Chiari osteotomy. A review of 58 cases.

Fifty-eight Chiari osteotomies performed in 51 patients were reviewed retrospectively. The indications for surgery were painful subluxation, instability, or poor acetabular coverage. The average age at surgery was 16 years (range, 7-45), and the average follow-up period was 40 months. The majority of the patients had congenital hip dislocation, but also included were patients with cerebral palsy, Legg-Calvé-Perthes disease, polio, infection, coxa vara, and epiphyseal dysplasia. Supplemental bone grafts were applied as needed. The functional results were unrelated to age, with 26 excellent, 28 good, and four poorly functional hips. After operation, 39 out of 41 had total pain relief, 41 out of 58 had a normal acetabular index, and 54 out of 58 had a normal center-edge angle. Trendelenburg gaits were unchanged by the Chiari osteotomy, but trochanteric transfer improved the gait in few cases.