[Complications after hip resurfacing using the ASR prosthesis in patients with osteoarthritis]

The purpose of this study was to evaluate peri- and postoperative complications and the clinical/radiological results after hip resurfacing with the ASR prosthesis in patients with osteoarthritis.

A prospective cohort study was performed including all patients who received a hip resurfacing (ASR prosthesis, DePuy, Motech, Warsaw, IN, USA) because of osteoarthritis between 1/2005 and 7/2006. 115 prostheses were performed in 110 patients (58 female, 52 male). In all patients a dorsal approach was used. The mean age was 57.82 years (range: 34 to 72 years) and the mean follow-up was after 12.5 months (range: 6 to 23 months). At the time of follow-up an X-ray (a. p. and axial) of the operated hip was performed in addition to the to standard clinical examination. To measure the functional outcome the Harris hip score was used.

We observed postoperative complications in 18 patients. Three non-trauma-related femoral neck fractures were seen after a mean of 58 days (range: 41 to 70 days). One trauma-related femoral neck fracture was found after 7 months. Neural complications were found in two patients. In 8 patients a revision of the acetabular component was necessary. 3 dislocations could be managed without further revision. One revision was necessary because of a persisting seroma without infection. No infections or thromboembolic complications were seen. The mean Harris hip score developed from preoperative 59 points (range: 50 to 65 points) to postoperative 96 points (range: 85 to 100 points).

Excellent early postoperative results can be reached by hip resurfacing. Special attention is necessary performing the correct positioning of the femoral and acetabular components. If notching is seen intraoperatively the operation should be switched and a large head prothesis should be implanted. Long-term results are still lacking.