Long-term experience with Chiari's osteotomy.

UNLABELLED: Fifty-six years after the introduction of Chiari's pelvic osteotomy, we report the long-term function scores and radiographic grade of osteoarthritis in 66 patients with 80 pelvic osteotomies with a minimum followup time of 27 years (average, 32 years; range, 27-48 years). These 66 patients were those who could be contacted and who returned for a followup visit from among 450 patients operated between 1961 and 1981. Thirty-two hips (40%) in 28 patients had undergone a total joint arthroplasty after an average 26 years (range, 13-41 years). Forty-eight hips in 41 patients (60%) were not replaced, their Harris hip score being a median of 82 points (range, 37-100 points). For the 22 patients for whom we had complete radiographs the average preoperative CE angle was 11.6 degrees, 48.6 degrees (range, 31 degrees-82.8 degrees) immediately postoperatively, and 41.6 degrees (range, 13.7 degrees-90 degrees) at last followup . Despite a functional hip score in most patients retaining their native hip, the degree of osteoarthritis progressed at last followup. We observed a similar mean age at the time of osteotomy in patients converted to total hip arthroplasty and those retaining their native hip. Age at time of surgery was inversely correlated (r = -0.78) with the interval between the osteotomy and THA. In this select patient group we found good functional outcome in patients who underwent Chiari pelvic osteotomy, with a conversion rate of 40% to total hip arthroplasty a mean of 32 years after the procedure. LEVEL OF EVIDENCE: Level IV, case series. See Guidelines for Authors for a complete description of levels of evidence.