Etiological analysis and Treatment Principles of Atypical Femur Fracture

Abstract Purpose: To investigate the etiology, clinical characteristics and treatment of atypical femur fracture (AFF) and to improve AFF recognition. Methods: The clinical data of 21 AFF patients treated in our hospital from January 2007 to June 2021 were retrospectively analyzed, and the clinical characteristics of AFF were summarized. 47 patients with the same age, gender and location of fracture were selected to establish the control group. The patients were classified according to the risk factors, and the clinical characteristics of AFFs were summarized. Results: 21 patients (27 femurs, six bilateral femurs) included 17 females, with an average age of 66.59±13.52 years (rang, 32-85 years). Through the relative risk analysis, it was judged that the long-term application of bisphosphonates (BPs) was the risk factor for the occurrence of AFFs. Using principal components analysis, it was concluded that severe osteoporosis, hip joint dysfunction and structural abnormality of the femur were also the risk factors for the occurrence of AFFs. A total of 5 patients with non-surgical treatment were selected, of which 2 cases were cured and the remaining 3 cases underwent surgical treatment. A total of 21 femurs for intramedullary nail fixation and 4 femurs for plate fixation. All fractures healed. Conclusions: The etiological factors of atypical femur fracture are complex.For high-risk patients, if there are prodromal symptoms or imaging examination indicates "simple transverse" femur fracture, it is necessary to be alert to the occurrence of AFF, and pay attention to whether there is AFF on the opposite side. The appropriate treatment will be chosen according to the characteristics of fracture.