Complete transiliac pelvic osteotomy for patients with developmental dysplasia of the hip without internal fixation

Several problems are encountered with pelvic osteotomy in hip dysplasia including insufficient coverage, avascular necrosis, graft instability and fixation of secondary bone grafts. We evaluated results of pelvic osteotomy in 4-8 year olds in our institution. 44 cases of developmental dysplasia of the hip between 1994 and 1999 were reviewed. 14 hips in 12 patients were treated with a step-cut osteotomy and the results are discussed. The mean age was 5.6 (range: 4-8) years, and mean follow up was 87.7 months (60-120). The patients were followed up according to the Severin clinical assessment criteria, and their radiological findings were evaluated and classified in accordance with the Tonnis criteria. Radiologically, a marked correction was obtained in center-edge angle, which was increased to 22.30 from the preoperative value of -11.20. No graft shift or loss was observed in any cases. There was also no loss in coverage achieved by surgical intervention. Coxofemoral positioning was found to be normal in eighty percent of cases. 8% of cases had avascular necrosis. Full range of hip motion was achieved in 84% of cases, and 84% of cases exhibited negative Trendelenburg's sign. The modified osteotomy we describe eliminated the need for fixation and secondary surgery. Graft stability and bone conservation were achieved.