We retrospectively evaluated the postoperative results of total hip arthroplasty (THA) in patients presenting with Crowe group IV dislocated hips. Overall, results were compared with regard to the type of osteotomy performed (Z or oblique) to define the correct indications for surgical technique and choice of prosthetic implant. Thirty-three subtrochanteric shortening and derotational osteotomies in primary THA were performed in 26 patients secondary to congenital hip dislocation. A Z osteotomy was performed in 14 cases and an oblique osteotomy in 19. The surgical approach was direct lateral, and surgery was aimed at restoring the anatomic hip center. Femoral and acetabular fixation was uncemented. The most used stem was the S-ROM (DePuy, Leeds, United Kingdom), and the couplings used were ceramic-ceramic (7 cases), ceramic-polyethylene (3 cases), metal-polyethylene (15 cases), and metal-metal (3 cases). Mean follow-up was 88±45 months. According to the Merle D'Aubigné score, the overall clinical results were good in 23 cases, satisfactory in 6, and fair in 4. Union of the osteotomy occurred in 97% of cases, and the mean time required for osteotomy union was 6±2 months without significant differences between Z and oblique osteotomies. At last follow-up, there was loosening of 1 cup and 1 stem, and revision was necessary. Twelve percent of patients experienced postoperative dislocation and 9% developed neuropraxia of the femoral nerve. The clinical and radiological results were similar in both groups, with a high rate of pain relief, an improvement in limb-length discrepancy, and reduced limping, leading to a smaller or no insole. Currently, the more complex Z osteotomy has been abandoned, because a modular stem prosthesis with metaphyseal sleeve allows the oblique osteotomy to be used with an easier and shorter surgical procedure.
Copyright 2011, SLACK Incorporated.