Burden of bisphosphonate-associated femoral fractures

Bisphosphonates decrease the risk of typical low trauma fractures, and are commonly prescribed for this indication. The link between atypical fractures and bisphosphonate use is well established; however, who is susceptible to atypical fracture remains unclear. A number of large population-based studies have disregarded the atypical fracture risk as they have found the absolute risk to be low.

This is a retrospective review of the radiographs and charts of all patients who presented with subtrochanteric and diaphyseal femoral fractures over a 5-year period. Patients were interviewed to determine functionality post-fracture.

Atypical fractures represented 30.3% of all diaphyseal and subtrochanteric femoral fractures. Ninety per cent of all atypical fractures were associated with bisphosphonate use. Atypical fracture patients were younger, more active and are independent prior to fracture and experienced significant complications and self-reported level of function and health declines post-fracture.

The burden of bisphosphonate-associated atypical fractures is significant. The aetiology of these fractures is unclear, and to date, no studies have demonstrated the significance of the injury for the patient. Prescription of bisphosphonate therapy for osteoporosis should be accompanied by ongoing surveillance and warning of the possibility of atypical and minimal trauma fractures.