Effect of Zoledronic Acid on Reducing Femoral Bone Mineral Density Loss following Total Hip Arthroplasty

This randomized trial evaluated the effect of zoledronic acid on femoral bone mineral density (BMD) following primary total hip arthroplasty. Bone mineral density was compared for up to 2 years in 27 patients receiving 5 mg zoledronic acid intravenous infusion and in 24 patients receiving placebo at 2 weeks and 1 year after surgery. Zoledronic acid prevented loss of bone mineral density at 1 year (+13.8% vs +1.4%, P=.0065) and 2 years (+14.3% vs −4.0%, P<.0001) in Gruen zone 1, at 1 year (−8.4% vs −25.4%, P<.0001) and 2 years (−9.6% vs −27.3%, P<.0001) in Gruen zone 7, at 6 weeks, 6 months, and 1 or 2 years in Gruen zones 4 and 6. For all Gruen zones, prevention of BMD loss by ZOL was significant at 6 weeks, 6 months, 1 year (+0.80% vs −6.03%, P<.0001) and 2 years (-0.16% vs −7.13%, P<.0001).