Bisphosphonate treatment and the risk of atypical femoral fracture among patients participating in a Fracture Liaison Service of a tertiary medical center

Summary Bisphosphonates are common treatment for osteoporosis. Among patients admitted with hip fracture, atypical femoral fractures (AFF) were more prevalent in those who were treated with Bisphosphonates for five or more years. Five years of Bisphosphonates treatment may signify an increased risk for AFF, though the absolute risk remains very low. Purpose Atypical femoral fractures (AFF) are a rare complication of bisphosphonate (BP) treatment. We evaluated the correlation between BP exposure and AFF risk among hip fracture patients. Methods This retrospective nested case–control study included patients over age 50 years, operated for osteoporotic hip fracture between July 2014 and November 2018, who attended our Fracture Liaison Service. We classified fracture radiographs and compared demographic, clinical, biochemical, and drug purchase data between patients with AFF and those with typical osteoporotic hip fracture (controls). To correct for the younger age of patients with AFF, we matched each case (AFF) with three controls according to age ( ± 1 year) and sex and performed a conditional logistic regression model. Results Of 989 patients, 31 (3