Anterior inferior tibiofibular ligament (AITFL) - avulsion fractures in 573 ankle fracture patients: Retrospective analysis of prevalence, morphology, radiographic detection, and correlation with fracture classifications.

Abstract

Avulsion fractures of the anterior inferior tibiofibular ligament (AITFL), historically described as Wagstaffe-Le Fort fractures, are under-recognized indicators of syndesmotic injury. This study aimed to determine the prevalence of AITFL avulsion fractures in ankle fractures, classify their morphology, evaluate fragment size, and assess correlations with established fracture classification systems. We retrospectively reviewed 1022 patients admitted with distal tibial and/or fibular fractures between January 2016 and June 2024 at a level I trauma center. After exclusions, 573 patients with ankle fractures and complete radiographic data were included. All patients underwent plain radiography. AITFL avulsion fractures were identified and classified into five types according to morphological criteria. Fracture mechanisms were analyzed using the Weber and Lauge-Hansen systems. Fragment size was measured and reported as median with interquartile range (IQR). AITFL avulsion fractures were identified in 116 of 573 patients, yielding a prevalence of 20.2 %. Type 2 was the most common variant (82.8 %), followed by type 4 (8.6 %). Type 2 fractures showed a strong association with supination-external rotation injuries and Weber B patterns, whereas type 4 fractures correlated predominantly with pronation-external rotation injuries and Weber C patterns (p< 0.05). Rare types (1 and 5) accounted for < 3 % of cases. The median fragment size was 16.6 mm (IQR 9.2-21.5), notably larger than previously reported. In several cases, fragment dimensions were sufficient to potentially interfere with syndesmotic alignment or fibular reduction. AITFL avulsion fractures are more frequent than traditionally appreciated, with reproducible associations between fracture morphology and specific injury mechanisms. Their relatively large size in many cases suggests potential feasibility for direct fixation, though treatment thresholds remain unproven. Recognition of these lesions may improve detection of syndesmotic injury and guide surgical planning. Prospective studies are needed to validate proposed size-based criteria and clarify their impact on clinical outcomes.