Radiographic and Demographic Factors Associated with Syndesmotic Screw Breakage in Ankle Fractures

Background: Syndesmotic screw breakage is a well-recognized mechanical complication following ankle fracture fixation. Although several studies have investigated patient-related and technical factors associated with screw breakage, the temporal pattern of screw failure and implant survival remains less clearly defined. Therefore, this study aimed to evaluate one-year syndesmotic screw survival using time-to-event analysis and to identify factors associated with screw breakage. Materials and Methods: A total of 132 patients with unstable AO-Weber 44-B/C ankle fractures treated with syndesmotic screw fixation were retrospectively analyzed. Patients were followed for a minimum of 12 months or until screw breakage occurred. Screw survival was evaluated using Kaplan-Meier analysis and Cox proportional hazards regression was performed to identify factors associated with screw breakage. Demographic variables, fracture type, and screw-related parameters were analyzed. Receiver operating characteristic (ROC) analysis was used to assess the discriminative ability of age. Results: Screw breakage occurred in 31 patients (23.5%) during follow-up. Kaplan-Meier analysis demonstrated significantly lower screw survival in Weber C fractures compared with Weber B fractures (log-rank p < 0.001). Cox regression analysis identified younger age (HR: 0.965, 95% CI: 0.937-0.993, p = 0.016) and Weber C fracture type (HR: 1.811, 95% CI: 1.260-2.602, p = 0.001) as independent predictors of screw breakage. ROC analysis showed that age had moderate discriminative ability (AUC: 0.719, 95% CI: 0.612-0.816), with a cut-off value of 35.5 years. Conclusions: Younger age and Weber C fracture type are associated with an increased risk of syndesmotic screw breakage and Weber C fractures also demonstrating reduced screw survival. These findings may assist in patient counseling; however, the clinical implications of screw breakage remain uncertain.