Atypical Fractures of the Femoral Diaphysis in Postmenopausal Women Taking Alendronate

The authors identified 15 postmenopausal women who had been receiving alendronate who presented with atypical low-energy fractures. Ten of the patients had a unique radiographic pattern that the authors call “simple with thick cortices.” To the Editor: The long-term safety of bisphosphonates for the treatment of osteoporosis has been questioned. Two case series have suggested a link between prolonged bisphosphonate therapy and atypical fractures. In one series, a small number of patients sustained low-energy nonvertebral fractures while receiving long-term alendronate therapy; three were fractures of the femoral shaft. 1 Bone biopsies in these patients showed evidence of severely suppressed bone turnover and fracture healing that was delayed or absent. In the other series, low-energy subtrochanteric fractures were found in nine women who had been receiving long-term alendronate therapy. 2 Theoretically, bisphosphonates suppress bone turnover and thus . . .