Bisphosphonate use and atypical fractures of the femoral shaft

January 01, 0001

Bisphosphonate use and atypical fractures of the femoral shaft

These Swedish authors report that in Sweden, 12,777 women 55 years of age or older sustained a fracture of the femur in 2008. They reviewed radiographs of 1234 of the 1271 women who had a subtrochanteric or shaft fracture and identified 59 patients with atypical fractures. Data on medications and coexisting conditions were obtained from national registries. The relative and absolute risk of atypical fractures associated with bisphosphonate use was estimated by means of a nationwide cohort analysis. The 59 case patients were also compared with 263 control patients who had ordinary subtrochanteric or shaft fractures.

They found: "The age-adjusted relative risk of atypical fracture was 47.3 in the cohort analysis. The increase in absolute risk was 5 cases per 10,000 patient-years. A total of 78% of the case patients and 10% of the controls had received bisphosphonates, corresponding to a multivariable- adjusted odds ratio of 33.3. The risk was independent of coexisting conditions and of concurrent use of other drugs with known effects on bone. The duration of use influenced the risk (odds ratio per 100 daily doses, 1.3. After drug withdrawal, the risk diminished by 70% per year since the last use (odds ratio, 0.28."

The authors concluded: "These 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."

Good reason to limit the duration of bisphosphonate use.

For the full abstract, click here.

N Engl J Med 364:1728-1737, 5 May 2011
© 2011 to the Massachusetts Medical Society
Bisphosphonate Use and Atypical Fractures of the Femoral Shaft. Jörg Schilcher, Karl Michaëlsson, and Per Aspenberg. Correspondence to Dr. Aspenberg: [email protected]

Category: M. Musculoskeletal. Keywords: bisphonphonates, femoral fracture, atypical fracture, case-control study, journal watch.
Synopsis edited by Dr Linda French, Toledo, Ohio. Posted on Global Family Doctor 20 May 2011

Pearls are an independent product of the Cochrane primary care group and are meant for educational use and not to guide clinical care.