Bilateral simultaneous femoral diaphyseal fractures in a patient with long-term ibandronate use.

Bisphosphonates are the most common medication used to treat patients with documented osteoporosis. Recently, reports have associated long-term bisphosphonate use with low-energy femur fractures. While no definitive mechanism has been associated, bisphosphonate use has been strongly implicated. This article presents the case of a 65-year-old woman with a 2-year history of ibandronate use presenting with simultaneous low-energy femoral shaft fractures. The patient reported prodromal bilateral thigh pain and was seen by a spine surgeon. A review of the literature implicates long-term ibandronate use in low-energy femur fractures. With most of the basic science studies demonstrating suppressed bone turnover after 5 years of treatment with alendronate, the significance of the present case also lies in the relatively short duration of time the patient was on ibandronate before suffering the bilateral femoral shaft fractures. Possible pathophysiology for the fractures includes suppressed bone turnover that may allow microcracks to propagate in cortical bone, which can weaken the bone and possibly predispose it to fractures. Patients who have been on bisphosphonates long term should be questioned about thigh pain and have radiographs of their femurs obtained if pain exists. Furthermore, if a patient presents with a single subtrochanteric or diaphyseal low-energy femur fracture after long-term bisphosphonate use, a radiograph of the contralateral femur should be obtained to assess for a cortical stress reaction.