Factors leading to osteoarthritis after eccentric rotational acetabular osteotomy.

UNLABELLED: We performed eccentric rotational acetabular osteotomy consecutively in 273 hips in 248 patients with hip dysplasia. Twenty-one patients were male and 227 were female. The average age was 37.7 years at the time of the index operation. Twenty-two hips had no osteoarthritis, 129 had early osteoarthritis, 117 had advanced osteoarthritis, and five had end-stage osteoarthritis. Twenty-six hips also were treated with concomitant intertrochanteric valgus osteotomy. Patients were followed for a minimum of 5 years after surgery. The average Harris hip score improved from 71 points preoperatively to 92 points at the final followup. Nine hips were converted to total hip arthroplasty as a result of deterioration after surgery. Kaplan-Meier survivorship analysis 15 years after the index operation indicated 97% in pre- and early stages and 87% in advanced and end stages when the end point was total hip arthroplasty. Risk factors identified by multivariate analysis for development of osteoarthritis of the hip 5 years after the index operation were body mass index (24 kg/m2 or more), concomitant valgus osteotomy, operative year between 1989 and 1992, a postoperative center-edge angle of Wiberg less than 25 degrees , and a postoperative horizontal distance of the femoral head from the tear drop (40 mm or more). LEVEL OF EVIDENCE: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.