Diaphyseal femur fractures associated with bisphosphonate use

Objective: The aim of this study was to investigate the association of bisphosphonate exposure with low-energy, non-articular femur fractures. Methods: The electronic records of 106 patients over the age of 55 years who sustained low-energy non-articular femur fractures and were treated within an integrated health system were examined. Patients were identified through a prospective registry and all fractures were classified anatomically. Cases were matched with control patients without fracture, and prescription orders were examined to assess drug exposures. Conditional logistic regression tested for a significant association between bisphosphonate exposure and fracture. Results: Thirteen of the 106 cases (12%) and 76 of 804 controls (9%) received at least one year of prescriptions for bisphosphonates prior to fracture. Odds ratio for bisphosphonate exposure as a risk factor was 1.52 (95% confidence interval: 0.76 to 3.05), suggesting no statistically significant association (p=0.24). Results were similar when four-year exposure or alendronates only were studied. Conclusion: Bisphosphonate exposure was not associated with non-articular femur fracture in this case-control study. We suggest that the majority of low-energy, geriatric femur fractures are not associated with bisphosphonate exposure.