Abstract
BACKGROUND: Distal tibiofibular syndesmosis injury is often associated with ankle fractures in adults. Injuries to the anterior/posterior inferior tibiofibular ligament (AITFL/PITFL) may present as a mid-substance tear or as an avulsion at insertion. Tibial and fibular avulsion of the AITFL is known as Tillaux fracture and Wagstaffe fracture, respectively. Tibial avulsion of the PITFL is referred to as a Volkmann fracture, and fibular avulsion of the PITFL is still undefined and has not been reported yet. The aim of this study is to summarize the incidence of these four avulsions, that is, tibial and fibular avulsions of the AITFL and PITFL. METHOD: Radiography and computed tomography (CT) imaging data of all adult patients with ankle fractures treated at our hospital between November 2010 and March 2023 were retrospectively analyzed. All ankle fractures were classified according to the Weber-AO and Lauge-Hansen classification systems by two experienced radiologists and two surgeons. The incidence of the four avulsions of the AITFL/PITFL was determined. RESULTS: In total, 1,770 ankle fractures in 1,758 patients were included in this study. The total incidence of avulsions at the four insertions of the AITFL/PITFL (occurring at one, two, or three insertions) was found to be 26.3% (465/1,770). Volkmann fracture had the highest incidence (19.9%, 353/1,770), and it was followed by Tillaux fracture (5.3%, 93/1,770), Wagstaffe fracture (3.3%, 59/1,770), and fibular avulsion of the PITFL (0.5%, 8/1,770). It is noteworthy that fibular avulsion of the PITFL has been reported here for the first time. The incidence of avulsion at one insertion was 23.6% (418/1770) and 2.7% (47/1770) at multiple insertions. CONCLUSION: In adult ankle fractures, avulsion occurs at the four insertions of the AITFL/PITFL in more than 25% of patients. The tibial insertion of the PITFL had the highest incidence of avulsion among the four insertions, while the fibular insertion of the PITFL had the lowest. The four types of avulsions can be isolated or in association with other avulsions. Future research studies on these four types of avulsion fractures would help in accurate diagnosis, decision-making and treatment of ankle Syndesmosis injuries. LEVEL OF EVIDENCE: Level III, retrospective cohort study.