Concomitant Factors Associated With Tillaux-Chaput Fractures in Adults: A Case-Control Study

Background: Tillaux-Chaput fractures (TCFs) consist of fractures of the anterolateral distal tibia. They rarely occur in isolation in adults. When TCFs are missed, there is a risk of chronic pain, instability, and ankle osteoarthritis. This study aimed to identify which factors are related to the presence of TCFs in ankle injuries. Methods: A retrospective review of 1134 ankle fractures evaluated between 2013 and 2023 at a level 1 trauma center was performed. Inclusion criteria were patients aged ≥18 years, ankle radiographs and computed tomographic (CT) scan evaluation, and the presence of a TCF confirmed by CT scan. Exclusion criteria were prior ankle surgery, pilon, or distal tibial fractures. A musculoskeletal radiologist and a foot and ankle–trained orthopaedic surgeon classified the TCFs into type 1, an extraarticular avulsion; type 2, a fracture involving the incisura fibularis; and type 3, a fracture with impaction of the anterolateral tibial plafond. A matching control group of ankle fractures without TCF was created with a 1:2 ratio. The following variables were collected: sex, age (<50 vs >50 years), ankle dislocation or subluxation, Weber classification, Maisonneuve fracture, type of medial and posterior malleolar fracture, Lauge-Hansen classification, malleoli involved, and osteochondral lesion of the talus. Multivariate logistic regression was performed to detect which variables had an association with the TCF and their subtypes. P value <.05 was considered significant. Results: A total of 481 ankle fractures had radiographs and CT scans available for evaluation, of which 83 (17.3%) had a TCF. Of these, 44.6% were type 1, 44.6% type 2, and 9.6% type 3. The mean age was 52.2 years; 66.3% were women. Six patients (7.2%) had an isolated TCF. Fifty-eight (69.9%), 50 (60.2%), and 62 (74.7%) ankles had involvement of the lateral, medial, and posterior malleolus, respectively. Age ≥50 years (OR 2.73, 95% CI 1.45-5.14) and pronation external rotation injuries (OR 2.94, 95% CI 1.43-6.06) had a significant association with TCF. Moreover, ankle dislocation or subluxation (OR 3.16, 95% CI 1.11-8.96) and the absence of posterior malleolar fracture (OR 5.97, 95% CI 1.65-21.6) were significantly associated with TCF type 2 and 3. Conclusion: In this study, age ≥50 years and pronation external rotation injuries were the unique independent risk factors for TCF. Furthermore, ankle dislocation or subluxation and the absence of posterior malleolar fractures increased the odds of having a more severe TCF. This study provides insights into the factors associated with TCF and its subtypes during adulthood.