Vascularized iliac bone-grafting for osteonecrosis with segmental collapse of the femoral head.

BACKGROUND

Vascularized iliac bone-grafting has been reported to be successful for patients with osteonecrosis of the femoral head. However, its benefit in patients with segmental collapse of the femoral head has not been determined. The purpose of this study was to analyze the results of vascularized iliac grafting in osteonecrotic femoral heads with segmental collapse.

METHODS

We retrospectively analyzed thirty-three hips in thirty-two patients in whom an osteonecrotic femoral head with segmental collapse (Association Research Circulation Osseous [ARCO] stage IIIA [<2-mm collapse] or stage IIIB [2 to 4-mm collapse]) had been treated with vascularized iliac bone-grafting between 1994 and 1999. The average age of the patients at the time of surgery was thirty-seven years. Twenty-six patients (twenty-seven hips) overused alcohol, five patients (five hips) had no known risk factor, and one patient (one hip) used corticosteroids for refractory bronchial asthma. Clinical outcomes were evaluated with the Harris hip score. We defined clinical failure as conversion to total hip replacement for any reason and radiographic failure as progressive femoral head collapse or secondary osteoarthritis of the involved hip.

RESULTS

At the conclusion of the study, only eight (24%) of the thirty-three hips were preserved. The mean survival time for the series as a whole was seventy-four months (95% confidence interval, fifty-four to ninety-five months) after the surgery. Eighteen of the twenty-six ARCO stage-IIIA hips were converted to a total hip replacement, and the mean survival time for the stage-IIIA hips was eighty-five months (95% confidence interval, sixty-one to 108 months). All of the seven ARCO stage-IIIB hips were converted to a total hip replacement, and the mean survival time for the stage-IIIB hips was thirty-five months (95% confidence interval, eleven to fifty-eight months). The mean Harris hip score for the eight hips that still survived at the time of follow-up had improved from 62 points to 80 points. However, all of them had progressive collapse of the femoral head-i.e., radiographic failure-at the time of final follow-up.

CONCLUSIONS

Vascularized iliac bone-grafting with use of the technique described in this study is not indicated for the treatment of osteonecrotic femoral heads with segmental collapse.