title: Mortality After Atypical Femoral Fractures: A Cohort Study.
abstract: Although osteoporotic fracture rates can be reduced by bisphosphonates, prolonged therapy is associated with higher risk of atypical femoral fractures. Ordinary fragility fractures are linked to high mortality rates. We aimed to determine whether atypical femoral fractures also confer excess mortality. Radiographs were reviewed for all patients aged ≥55 years who had experienced a subtrochanteric or femoral shaft fracture in Sweden in 2008 to 2010. The fractures were classified as either atypical or ordinary. Data on medication use, coexisting conditions, and date of death were obtained from national registers. We estimated multivariable-adjusted relative risks of death after atypical femoral fractures compared with ordinary subtrochanteric or femoral shaft fractures and calculated age- and sex-standardized mortality ratios (SMRs) for atypical and ordinary fractures compared with the population average. During a mean of 4 years of follow-up, 39 of 172 (23%) patients with an atypical fracture had died compared with 588 of 952 (62%) with an ordinary fracture, corresponding to a relative risk of 0.51 (95% confidence interval [CI] 0.38-0.68). The lower risk was evident in both users and nonusers of bisphosphonates. No patient with atypical fracture died in the first year after fracture. Individuals with an ordinary fracture had a higher mortality risk than the general population (SMR = 1.82; 95% CI 1.69-1.99), but no excess risk was found in patients with atypical fracture (SMR = 0.92; 95% CI 0.65-1.26). We conclude that in contrast to ordinary subtrochanteric and femoral shaft fractures, atypical femoral fractures are not associated with excess mortality.
authors.affiliation: Section of Orthopedics, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Kharazmi
authors.affiliation: Department of Medical Sciences, Uppsala University, Uppsala, Sweden.
authors.forename: Pär
authors.initials: P
authors.lastname: Hallberg
authors.affiliation: Section of Orthopedics, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, Linköping, Sweden.
authors.forename: Jörg
authors.initials: J
authors.lastname: Schilcher
authors.affiliation: Section of Orthopedics, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, Linköping, Sweden.
authors.forename: Per
authors.initials: P
authors.lastname: Aspenberg
authors.affiliation: Section of Orthopedics, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden.
authors.forename: Karl
authors.initials: K
authors.lastname: Michaëlsson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D016001:Confidence Intervals; D004164:Diphosphonates / Q000009:adverse effects; D005260:Female; D005264:Femoral Fractures / Q000139:chemically induced / Q000401:mortality*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D013548:Sweden / Q000453:epidemiology
chemical_list: D004164:Diphosphonates
keywords: ATYPICAL FRACTURE; BISPHOSPHONATES; FEMORAL FRACTURE; MORTALITY; OSTEOPOROSIS