Leclerc JT, et al. - A retrospective radiological review of all femoral fractures between January 1, 2006 and March 31, 2015 in Quebec City, Canada was conducted to assess the prevalence and clinical and radiological risk factors related to atypical periprosthetic femoral fractures (APFFs) in patients with hip and knee arthroplasties. Among periprosthetic femoral fractures (PFFs), the prevalence of APFFs was 8.3% (11/133). Findings suggested an association of a transverse fracture, a periosteal thickening of the lateral cortex at the fracture, a unicortical fracture, and prodromal symptoms with APFFs. Compared to PFFs, the type of implant, its positioning, and the femoral geometry did not seem to be risk factors for APFFs. Among alendronate users vs risedronate users, an increased risk of APFFs was seen.