Abstract
The purpose of this study was to evaluate the long-term clinical and radiological results of patients with hip dysplasia who underwent spherical acetabular osteotomy. The surgical technique used was that described by Wagner.
The first 26 unilateral spherical osteotomies performed by one surgeon at one institution were reviewed at a minimum clinical follow-up of 20 years (median 23.9, maximum 29 years). One patient had died 5 years after the index operation unrelated to the procedure. Three patients (3 hips, 11 %) could not be traced. Preoperative and follow-up radiographic measurements included lateral and anterior centre-edge angle, acetabular index angle, and acetabulum-head index of Heyman and Herndon. Antero-posterior radiographs of the pelvis were evaluated for the presence of joint congruency, joint space narrowing, increased sclerosis of the subchondral bone, and bone cysts.
Osteotomy improved the mean lateral centre-edge angle from −20 to +130, and the acetabular head index from 52% to 72%. The mean postoperative anterior centre-edge angle of Lequesne and de Seze was 23 (range: −10 to 62). Seven of 22 hips (32%) needed conversion to total hip replacement. The average Harris hip score at latest follow-up of the remaining 15 hips was rated 86 points (range: 50 to 100 points). Overall, 11 of the 15 hips were clinically rated good or excellent. On latest follow-up severity of osteoarthritis was unchanged in 13 of 15 hips. Only 3 of 9 hips requiring conversion to total hip replacement or showing progressive osteoarthritis were rated congruent after the index operation. On the other hand, 10 of 13 hips not requiring conversion to total hip replacement or progressive osteoarthritis were congruent. The 20-year-follow-up Kaplan-Meier survival estimates based on conversion to total hip replacement as an end point was 86.4%. (95% confidence interval: 63.4% to 95.4%). The 25-year-follow-up survivorship was 65.1 % (95% confidence interval: 35.6% to 83.7%).
The long-term results of the spherical osteotomy are satisfactory from the standpoint of both improvement in clinical condition and the radiological appearance of the joint. The Wagner spherical osteotomy had prevented progression of degenerative changes in 13 out of 22 hips (59%) after a median 23.9 year follow-up. Congruency of the joint seems to be a major factor predicting long-term outcome.
Correspondence should be addressed to the editorial secretary: Associate Professor Jean-Claude Theis, Department of Orthopaedic Surgery, Dunedin Hospital, Private Bag 1921, Dunedin, New Zealand.
