The acetabular response to proximal femoral varus rotational osteotomy
was studied radiographically in twenty-eight patients who had had
thirty-three congenitally dislocated hips. All of the patients had
previously been managed with open or closed reduction followed by use of a
spica cast and had worn an abduction orthosis for at least one year after
the reduction. The indications for the femoral osteotomy were a
persistently increased acetabular index or subluxation, or both. The
average of the patients at the time of the femoral osteotomy was
twenty-five months. The average preoperative acetabular index was 32
degrees. At an average of seven years after the osteotomy, the acetabular
index had improved to an average of 16 degrees. Four hips had had one
subsequent procedure for persistent acetabular dysplasia. Despite a failure
of the acetabulum to respond to use of an abduction splint, the proximal
femoral varus rotational osteotomy stimulated improvement in the acetabular
index to within normal limits in twenty-nine of the thirty-three hips.