ABSTRACT
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 2years in 27 patients receiving 5mg zoledronic acid intravenous infusion and in 24 patients receiving placebo at 2weeks and 1year after surgery. Zoledronic acid prevented loss of bone mineral density at 1year (+13.8% vs +1.4%, P=.0065) and 2years (+14.3% vs -4.0%, P<.0001) in Gruen zone 1, at 1year (-8.4% vs -25.4%, P<.0001) and 2years (-9.6% vs -27.3%, P<.0001) in Gruen zone 7, at 6weeks, 6months, and 1 or 2years in Gruen zones 4 and 6. For all Gruen zones, prevention of BMD loss by ZOL was significant at 6weeks, 6months, 1year (+0.80% vs -6.03%, P<.0001) and 2years (-0.16% vs -7.13%, P<.0001).
