Atypical Femoral Fractures Induced by Anti-Resorptive Medications

This review evaluates established risk factors, examines pathogenic mechanisms, determines optimal treatment durations, and proposes evidence-based management strategies for Osteoporosis to enhance clinical practice.

Key risk factors include advanced age, Asian descent, prolonged Bisphosphonates therapy (exceeding 5 years for alendronate or 3 years for zoledronic acid) without drug holidays, and distinct femoral geometry. The underlying pathophysiology is primarily linked to excessive suppression of bone turnover, resulting in progressive microdamage accumulation. Current clinical guidelines suggest implementing Bisphosphonates treatment interruptions (1-3 years for oral regimens; 3-5 years for intravenous administration) in patients with moderate fracture risk (femoral neck T-score > -2.5). Importantly, denosumab withdrawal necessitates a transition to alternative therapies-typically Bisphosphonates or teriparatide-to mitigate rebound bone loss. For managing Atypical Femoral Fractures, teriparatide demonstrates efficacy in promoting healing of active lesions, whereas intramedullary nailing represents the gold standard for complete fractures or high-risk incomplete fractures. Atypical Femoral Fractures management requires balancing Anti-Resorptive benefits against risks via individualized treatment, timely drug holidays, and rapid transition to bone-forming agents post-denosumab. Prophylactic surgery benefits high-risk fractures. Future research should elucidate denosumab's mechanisms and develop targeted therapies.