Title : Silent snap: A decade of Atypical Femoral Fractures (AFFs) and what we’re still missing
Abstract:
Background: Atypical Femoral Fractures (AFFs) are rare, low-energy fractures predominantly affecting the subtrochanteric or femoral shaft. They are strongly associated with prolonged antiresorptive therapy, particularly bisphosphonates and denosumab. Though rare, AFFs carry significant morbidity and are often preceded by radiographic changes such as cortical thickening or transverse lucencies. Notably, 40–50% of patients with unilateral AFF may develop a contralateral lesion, underscoring the need for early recognition and consistent follow-up.
Aim: This audit assesses the diagnosis and management of AFFs at Nottingham University Hospitals (NUH) over the past decade. We aim to identify care gaps and develop a checklist to improve early detection and consistent management.
Methodology: A retrospective study was conducted of all AFF cases at NUH from 2015 to 2024. Data collected included demographics, fracture features, imaging, blood tests, multidisciplinary involvement, documentation, and treatment.
Results: 19 patients were identified over 10 years (mean age 76.5; 95% female). (N=19) Contralateral femur X-rays were requested in 16/19 cases, with atypical changes found in 2/16. The report of contralateral X-rays was discussed with orthopedic team (4/16). Bone profiles were completed in all cases, and fasting plasma CTx was done in 17/19. Initial X-rays were formally reported by a consultant radiologist in 6/19 cases and reviewed by a musculoskeletal radiologist in 5/19. The diagnosis of “AFF” was documented in 11/19 discharge letters, but only 2/19 patients were informed. Referrals to the bone health clinic were made in 15/19, and bisphosphonate alert was added to patient records in 9/19. Culprit medications included alendronate (15/19), risedronate (1/19), denosumab (1/19), ibandronate (1/19), and zoledronate (1/19).
Conclusion: This audit highlights inconsistent practices in the recognition and management of AFFs. Key steps such as contralateral imaging, specialist radiology input, and clear patient communication were frequently overlooked. Absence of unified local or national guidance contributes to variability in care. We propose the development of a practical, multidisciplinary checklist to standardize assessment, documentation, and follow-up in patients with suspected or confirmed AFF.
