Total hip arthroplasty with a monoblock conical stem and subtrochanteric transverse shortening osteotomy in Crowe type IV dysplastic hips

PURPOSE: This series assessed the clinical and radiographic outcomes of total hip arthroplasty (THA) with femoral shortening osteotomy for the management of patients with Crowe type IV hip dysplasia. METHODS: Only patients with Crowe type IV hip dysplasia who underwent primary THA combined with a subtrochanteric transverse osteotomy with an uncemented monoblock conical stem were included. The clinical and radiographic evaluations were performed before and immediately after surgery, and at last follow-up. The hip function was assessed with the Harris Hip Score (HHS). RESULTS: Seventy-four patients (102 hips) with a mean age of 53.9 (range, 20-83) were evaluated at an average follow-up of 11.3 years (range, 5-25). Stem revision occurred in two (1.9%) cases, with a survivorship of 95.9% (95%IC, 91.9-99.9%) at ten years. The average HHS increased from 44 (range, 15-78) pre-operatively to 90.3 (range, 62-100) at last follow-up (p < 0.001). Osteotomy site non-union and early dislocation were observed in 3.9 and 3.8%, respectively. No cases of nerve palsy were reported. CONCLUSIONS: THA with a monoblock conical stem associated with subtrochanteric transverse osteotomy provides good long-term survival, clinical and radiographic results. It may be considered an effective management of patients with Crowe IV hip dysplasia.