Short term clinical outcome of a porous tantalum implant for the treatment of advanced osteonecrosis of the femoral head.

PURPOSE OF THE STUDY: Osteonecrosis of the hip mostly affects young individuals and often progresses to a debilitating disease. Several treatment modalities exist, but none are completely satisfactory. This study evaluates the clinical outcome of patients treated with core decompression and insertion of a porous tantalum implant in the femoral head. This procedure is similar to commonly performed procedures, but has the additional advantages of providing structural support to the necrotic femoral head while having no donor-site morbidity.

METHODS: We evaluated 15 patients with 18 osteonecrotic hips with Steinberg stage III (3 hips) and IV (15 hips) disease. The mean age of the patients was 42 years-old (eldest 66), and the mean time for follow-up was 23 months. The outcome measure was hip function, evaluated with the Harris hip score, and the end point was total hip arthroplasty, or referral for this procedure.

RESULTS: The success rate at twelve months postoperatively was 77.8%, and the overall success rate was 44.5%. Failures occurred at a mean time of 11.7 months, and one complication, a periprosthetic fracture, occurred 4 months postoperatively. On average, patients who did well improved their Harris hip scores by 21.7 points, and patients who eventually required arthroplasty decreased their scores by 14 points.

CONCLUSIONS: Core decompression with porous tantalum implants showed encouraging success rates and early clinical results in patients with advanced stage osteonecrosis, but further larger scale studies are required to identify the population best suited for this procedure.