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Bisphosphonate use and atypical fractures of the femoral shaft Full Text
New England Journal of Medicine, 05/09/2011
Clinical Article
Schilcher J et al. - The population-based nationwide analyses may be reassuring for patients who receive bisphosphonates. Although there was a high prevalence of current bisphosphonate use among patients with atypical fractures, the absolute risk was small.
Methods- In Sweden, 12,777 women 55 years of age or older sustained fracture of femur in 2008
- Reviewed radiographs of 1234 of 1271 women who had subtrochanteric or shaft fracture and identified 59 patients with atypical fractures
- Data on medications and coexisting conditions obtained from national registries
- Relative and absolute risk of atypical fractures associated with bisphosphonate use estimated by means of nationwide cohort analysis
- 59 case patients compared with 263 control patients who had ordinary subtrochanteric or shaft fractures
- Age-adjusted relative risk of atypical fracture was 47.3 (95% CI, 25.6 to 87.3) in cohort analysis.
- Increase in absolute risk was 5 cases per 10,000 patient-years (95% CI, 4 to 7)
- Total of 78% of case patients and 10% of controls had received bisphosphonates, corresponding to multivariable-adjusted OR of 33.3 (95% CI, 14.3 to 77.8)
- Risk was independent of coexisting conditions and of concurrent use of other drugs with known effects on bone
- Duration of use influenced risk (odds ratio per 100 daily doses, 1.3; 95% CI, 1.1 to 1.6)
- After drug withdrawal, risk diminished by 70% per year since last use (OR 0.28; 95% CI, 0.21 to 0.38)
