Long-Term Results of Total Hip Arthroplasty with Step-Cut Osteotomy in Crowe Type IV Dysplastic Hips.

Objective: The purpose of this study was to evaluate the long-term results of sub-trochanteric step-cut shortening osteotomy (SSCO) used in the total hip arthroplasty (THA) procedure for treatment of Crowe type IV dysplastic hips. Materials and Methods: Crowe type IV dysplastic 35 hips of 31 patients were treated with cementless THA. Patients were followed up meanly 9.2 years (range 4-18). SSCO was applied to all hips to reduce the femoral head into the true acetabulum. Autologous bone grafts which were obtained by shortening the femur and cable cerclage wires were used for fixing the osteotomy site. The results were evaluated clinically and radiologically. In clinical evaluation, Harris hip score (HHS) and d'Aubigne hip evaluation criteria were used. Results: The mean HHS increased from 40.6 to 92.5. Merle d'Aubigne hip evaluation score was increased on average from 1.76 to 5.8 in terms of pain and from 2.9 to 5.5 in terms of range of motion. In 9 hips (25.7%), medialization was achieved by creating a controlled fracture in the acetabulum. The hip rotation center was lowered by an average of 5.7 cm. The average leg lengthening was 3.4 cm. No more than 4 cm lengthening was made. Dislocation did not develop in any of the patients. Conclusion: It was concluded that the long-term results were found to be successful in the THA with SSCO in Crowe type IV dysplastic hips, since nerve complications were reduced, leg-lengthening was achieved, and a painless and mobile hip joint could be achieved.