Atypical Femoral Fracture in a Patient without Bisphosphonate or Denosumab Exposure-A Case Report

INTRODUCTION: Atypical femoral fractures (AFF) are associated with the use of bisphosphonates (BPs) or denosumab. However, few cases that meet the characteristics of these fractures, as established by the American Society of Bone and Mineral Research, have occurred in patients who have never used antiresorptive drugs. CASE REPORT: We report a case of AFF in a 67-year-old woman who had never used antiresorptive medications. The history and comorbidities of the patient, the characteristics of the fracture, and the subsequent treatment are presented. CONCLUSION: AFFs may occur even in patients who have never been exposed to BPs or denosumab. The absence of antiresorptive osteoporosis therapy and the lack of radiographic focal periosteal reaction in the lateral femoral cortex, as in our case, can make it difficult to detect and prevent the disorder. Prolonged use of proton pump inhibitors and Vitamin D deficiency-related osteomalacia may contribute to the occurrence of these fractures. Further studies are required to accurately understand all inciting factors contributing to the development of AFFs.