Abstract
Introduction
Osteonecrosis (ON) is one of the most debilitating skeletal disorders. Most patients with ON of the femoral head eventually require surgery, usually total hip arthroplasty, within a few years of disease onset. Previous reports have shown that alendronate reduces osteoclastic activity and reduces the incidence of femoral head collapse in osteonecrotic hips. A randomized study to examine the ability of alendronate to delay or prevent femoral head collapse was performed.
Methods
From June 2005 to December 2006, sixty four patients were enrolled and randomly assigned to alendronate or placebo. Five patients were excluded from the analysis because of their failure to adhere to the study protocol. Disease progression was evaluated using radiographs and magnetic resonance imaging (MRI).
Results
While the proportion of patients in the alendronate group who underwent total hip arthroplasty was 13% (4 of 31 patients), the proportion of patients undergoing the procedure in the placebo group was 29% (8 of 28 patients; p=0.22, cumulative incidence between the two groups by log-rank test). As such, there was a numerical reduction in the rate of total hip arthroplasty in the alendronate group compared to placebo that did not achieve statistical significance likely because the study was originally powered to detect a between-group difference based on event rates of 35.7% and 3.4% in the placebo and alendronate groups, respectively.
Conclusion
Alendronate treatment shows promise for the treatment of atraumatic osteonecrosis. However, additional studies are needed to confirm our results. Osteotomy or bone grafting still remains the procedure of choice for osteonecrosis of the femoral head prior to collapse.
Disclosure
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The study was supported in part by Merck Sharp & Dohme (I.A) Corp. Taiwan Branch
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All these schools received some financial reimbursement for the study
