Summary

The HORIZON Pivotal Fracture Trial [NCT00049829] showed that once-yearly zoledronic acid significantly reduces the risk of vertebral, hip, and other fractures [Black D et al. N Engl J Med 2007]. This article discusses the results of a planned subanalysis from HORIZON that evaluated the effect of prior bisphosphonate use on the primary endpoints of new vertebral fracture (in patients who were not taking concomitant osteoporosis medications) and non-vertebral fractures (in all patients).