151. RESULTS OF TWO METHODS OF FEMORAL SHORTENING OSTEOTOMY IN HIP ARTHROPLASTY FOR HIGH RIDING DEVELOPMENTAL DYSPLASIA OF THE HIP

Abstract

Purpose: Total hip arthroplasty in high riding congenital dislocation of the hip is a challenging procedure. In order to position the cup in the true acetabulum, femoral shortening osteotomy is often needed. The purpose of our study was to evaluate the results of two different methods of femoral shortening osteotomy.

Method: Thirty-one total hip arthroplasties were performed in 29 cases with high congenital hip dislocation. The acetabular cups were placed at true acetabulum and femoral shortening osteotomies of the femur were performed at proximal (14 hips, group 1) or distal femur (17 hips, group 2). After a mean follow up of 4.2 years, all 31 hips were evaluated with Harris Hip Scores and X-rays. Technical difficulties and complications were also reported.

Results: The mean increase in Harris Hip Score was 51 in group one and 52 in group two. There was one peroneal nerve palsy and one early dislocation in group 1, while there was no such perioperative complications in group 2. One acetabular cup and femoral stem were revised in group 1. Non-union happened in two cases of group 2. Special shape (cylindrical, non-tapered and longer than standard) femoral stems were needed for most proximal osteotomy patients.

Conclusion: Hip arthroplasty, with insertion of cup at true acetabulum and femoral shortening osteotomy in patients with high congenital dislocation, can produce good results. Either proximal or distal femoral shortening osteotomy could have advantages and disadvantages. Proximal shortening osteotomy is a more challenging procedure, may need special stem design, and could compromise stem fixation.