Surgical Treatment for Bisphosphonate-related Atypical Femoral Fracture: A Systematic Review

Background: Atypical femoral fractures are the femoral fractures located anywhere between the lesser trochanter and the supracondylar flare of the femur. Long-term bisphosphonates, as the most common preventive and treatment medications for osteoporosis, are thought to have an important role in these fractures. Most of the fractures should be treated surgically, and the complications are considerable. Methods: We searched Medline, CENTRAL, Embase, and DART on February 26, 2020. One author reviewed and retrieved citations from these four databases for irrelevant and duplicate studies, and two other authors independently extracted data from the studies and rated their quality. Patients with surgical treatment of bisphosphonate-related atypical femoral fracture, according to the American Society for Bone and Mineral Research definition, were included. Animal studies, case reports, studies with high-energy trauma, pathological fracture, or malignancy-related fractures were excluded. Results: In total, 316 patients (348 fractures) were included in this study. Mean age of patients was 70.47 years, and 97.5% of them were female. Duration of using bisphosphonates was 4.04 to 8.8 years, and Alendronate was the most common type. Moreover, 65.27% and 34.72% of the reported fractures were in diaphyseal and subtrochanteric, respectively. Moreover, the most common fixation type was intramedullary. Rate of complication was 17.52%, and the most frequent one was non-unio‎n, followed by implant failure. The main limitation of this research was that most of the studies did not have a high level of evidence. Conclusion: An increase in the rate of atypical femoral fracture with its challenging management makes it an important issue to be noted by orthopedic surgeons. Based on the results of this study, subtrochanteric fractures might have more complications post-operatively and are suggested to be operated on by more experienced surgeons. It was also found that extra-medullary fixation increases the risk of complications. Future studies on unio‎n time, outcomes of different surgical methods, and teriparatide therapy may help shed more light on the surgical management of these fractures.