Femoral varus and acetabular osteotomies in cerebral palsy.

Sixty-three patients with cerebral palsy underwent proximal femoral varus derotation osteotomy for 86 subluxing or dislocating hips. Eleven hips underwent concomitant pelvic osteotomy. Adductor tenotomy was performed in all patients. The average preoperative femoral neck shaft angle was 158.2 degrees, with a center edge angle of -2 degrees. Femoral osteotomy effected an average femoral neck shaft angle of 132.2 degrees, with a center edge angle of +8 degrees. A Chiari osteotomy was performed when the acetabular index was greater than 35 degrees. This preoperative acetabular index of 46 degrees improved to 28 degrees postoperatively, and proved to be the most reliable indicator for need of an added pelvic osteotomy.