We have investigated the factors which affect the progression of osteoarthritis after rotational acetabular osteotomy (RAO).

Between 1984 and 1998, we treated 60 dysplastic hips by RAO. The mean age at surgery was 31.6 years (13 to 51) and the mean period of follow-up was 4.6 years (2 to 9.5). The thickness of the articular cartilage on the weight-bearing area, pre- and postoperative acetabular cover, and the sphericity of the femoral head were used for radiological assessment.

The osteoarthritis did not progress in 39 hips. Significant factors which affected the radiological grade included sphericity of the femoral head and the postoperative acetabular cover. The surgical approach and preoperative acetabular cover did not affect the progression of osteoarthritis. Patients were divided into two groups according to the surgical approach used, either conventional (23 hips) or modified (37 hips). Significant factors included the postoperative acetabular cover in the modified approach, and the sphericity of the femoral head in the conventional approach.

It is critical that the postoperative cover is sufficient, especially when RAO is carried out using our modified technique.

We reviewed 19 children with 24 congenital club feet at a mean of 11 years after one-stage posteromedial release at the age of five years or older (mean 6.8 years). Thirteen feet had undergone previous surgery. Nineteen feet were functionally excellent or good, three were fair and two had required subtalar arthrodesis. Radiographs showed good alignment of the tarsal bones, although mild adduction or varus deformity remained in several feet. Deformities of the bones were more common in feet which had had previous surgery.