Prevalence and risk factors for AFF among Lebanese patients with hip and shaft fractures

This retrospective study investigates the prevalence of atypical femoral fractures (AFFs) among patients admitted with hip and shaft fractures at a tertiary referral center in Beirut, Lebanon. We analyzed electronic medical records and radiology studies of patients aged above 40 admitted with hip and shaft fractures between January 2006 and December 2019. Fractures were confirmed by ICD9 or ICD10 codes. All cases were reviewed by radiologists, and AFFs were identified according to the 2013 revised American Society of Bone and Mineral Research (ASBMR) criteria. We identified 1366 hip and shaft fracture patients, of which 14 female patients had 19 AFFs. This represents a prevalence of 1.0% among all hip and shaft fractures patients and 1.7% among all female hip and shaft fracture patients. Bilateral AFFs were found in five of the 14 patients. Patients with AFF tended to be younger, with a mean age of 74.3 (±8.6) years compared to 78.0 (±10.6) for patients with non-AFF fractures. 36% of AFF patients had a prior history of non-traumatic fracture at first admission. A high percentage of patients with AFFs reported intake of proton pump inhibitors (42.9%) and glucocorticoids (21.4%). Bisphosphonate exposure was noted in 64.3% of AFF patients. None of the AFF patients were active smokers or consumed alcohol regularly. Bone Mineral Density assessments were available for seven AFF patients, indicating osteoporosis in four and osteopenia in three cases. Hip Axis Length measurements showed no significant difference between AFF patients (N = 7) and sex and age-matched controls (N = 21). The study underlines the prevalence and characteristics of AFFs in Lebanon, which is consistent with the numbers reported in the literature (0.32 - 5%). A larger prospective study that includes hospitals across the nation is needed to gain a more comprehensive view of the prevalence of AFFs in the Lebanese population.