SAT-784 The Role of Full Femur Imaging for Early Detection of Incomplete Atypical Femur Fractures

Abstract Disclosure: A.B. Humrickhouse: None. D. Eagerton: None. A.G. La Rochelle: None. Introduction: Atypical femur fractures (AFFs) are a rare but serious complication linked to prolonged use of bisphosphonates and denosumab. These low-trauma fractures are defined by characteristic radiographic features and often go undetected until they progress to complete fractures. While the incidence of AFFs is low compared to typical osteoporotic fractures, early detection is crucial, and clear guidelines for screening and management are still limited. Full femur imaging (FFI) has the capability to identify incomplete atypical femur fractures (iAFF) and pinpoint high-risk patients. Focal periosteal and endosteal thickening on the lateral cortex can detect early abnormalities, allowing for timely prophylactic interventions to prevent complete fractures. Despite its potential, FFI is not routinely included in dual-energy X-ray absorptiometry (DXA) scans across all centers, raising concern for missed prophylactic opportunity. Integrating FFI as a standard component of osteoporosis management could enhance early detection and guide intervention strategies. Case Report: We present the case of an 83-year-old female with a history of type 2 diabetes mellitus, hypothyroidism, hyperlipidemia, and long-term osteoporosis treatment. After seven years on alendronate, she sustained a complete right AFF requiring intramedullary nailing. Her treatment was transitioned to denosumab, and she remained stable without additional fracture for eight years. A follow up DXA with use of FFI was performed after nine years of denosumab therapy and indicated the lowest T-score of -0.7 in the left hip, however the use of FFI suggested a left iAFF and was confirmed on follow up imaging. Prophylactic intramedullary nailing was performed, denosumab was discontinued, and post-operative anabolic options were discussed. This case highlights the advantage of detecting iAFF with the use of FFI to enable timely prophylactic intervention. Discussion: AFFs present significant challenges in osteoporosis management. The risk has been shown to increase with the duration of bisphosphonate or denosumab use, revealing the value of screening and early detection. The International Society for Clinical Densitometry advises bilateral FFI for AFF detection after three years of these medications or within a year of stopping. Imaging strategies, such as FFI, can play a pivotal role in detecting incomplete fractures, preventing fracture progression, and reducing patient morbidity. Incorporating FFI into routine osteoporosis care is not routinely implemented and may highlight a gap in current practice. This case emphasizes the need for clear guidelines on screening for AFFs and the potential role of FFI in personalized imaging protocols to enhance patient care. Presentation: Saturday, July 12, 2025