CUSTOM UNCEMENTED ARTHROPLASTY WITH SUBTROCHANTERIC DEROTATIONAL OSTEOTOMY FOR SEVERE FEMORAL ANTEVERSION IN HIP DYSPLASIA

Abstract

Introduction: Patients with developmental dysplasia of the hip with secondary osteoarthritis are often found to have severe anatomical deformities of the hip. Total hip replacement in such patients is a complex undertaking associated with complication and failure rates. Subtrochanteric derotational osteotomy with customized uncemented total hip arthroplasty has been described to combat the problems of severe femoral anteversion. We present the medium term follow up of 12 patients where such a procedure was undertaken.

Materials and Methods: 11 female and 3 male patients with an average age of 49 (range, 32–79 years) were reviewed by an independent observer. The mean follow up was 50 months (range, 24–93 months). Patients were classified on AP radiographs according to Crowe and Hartofilakidis. All have femoral neck anteversions of greater than 45° on CT scans. The patients were followed up radiographically and clinically using the WOMAC, Oxford and Harris hip scores.

Results: 1 patient died due to unrelated causes. The average Harris hip score improved from 44 (range, 38–57) preoperatively to 88 (range, 67–94). The average WOMAC score improved from 83 (range, 45–112) pre-operatively to 36 (range, 25–72). The average Oxford score improved from 44 (range, 38–57) preoperatively to 19 (range, 14–34). Radiologically, the prosthesis appears to have osseointegrated with union of the osteotomy site in all cases and there is no evidence of implant migration or osteolysis.

Conclusion: Custom total hip arthroplasty with subtrochanteric osteotomy provides a method whereby the hip centre can be restored to its normal level, proximal bone stock is preserved and a more normal proximal femoral morphology is created. We have undertaken this procedure routinely in patients with excessive femoral anter-version and report excellent medium term clinical and radiographic results.