Special Considerations in Management of Atypical Femur Fractures

Atypical femur fractures (AFFs) are problematic due to the high incidence of osteoporosis in the growing aging population. There are several factors that lead to increased risk of AFFs including bisphosphonate use, increasing age, female sex, and certain femoral morphologies. The pathogenesis of AFFs involves the combination of altered bone remodeling and unfavorable mechanical environment. AFFs are associated with low energy mechanisms and are diagnosed with clinical history and standard femur radiographs. While the complete management of AFFs always involves medical and endocrinological work-up, most commonly it is also associated with surgical intervention. Evaluation of the contralateral femur is also paramount to optimizing outcomes in patients with incomplete or complete AFFs. The surgeon managing AFFs must be aware of certain fracture-specific issues when treating these fractures, including the risk of nonunion, varus collapse, excessive anterolateral bowing, endosteal thickening at the level of the fracture leading to fracture malreduction with nail passage, and possibility for cortical perforation. This review will outline various surgical techniques helpful in the surgical management of AFFs. Patient should be adequately counseled regarding the high rates of complications including delayed and nonunion.