Role of Computed Tomography Scan in Preoperative Planning for Tillaux-Chaput Fractures in Adults

Category: Ankle; Trauma Introduction/Purpose: Tillaux-Chaput fractures (TCF) occur in the anterolateral rim of the distal tibia. When the TCF is not treated correctly, there is a risk of chronic pain, instability, and post-traumatic osteoarthritis. Although the role of computed tomography (CT) scan has been investigated in the operative planning of ankle fractures, its role in the operative planning of TCF is unknown. This study aimed to evaluate the role of the CT scan in the preoperative planning for TCF in adults. Methods: A retrospective review of ankle fractures evaluated in the emergency and outpatient department between 2013-2023 was performed in a university hospital. Inclusion criteria were patients aged≥ 18 years, radiograph and CT-scan evaluation, and the presence of TCF confirmed by CT-scan. Exclusion criteria were distal tibial/pilon fractures, or prior ankle surgery. Three foot and ankle surgeons assessed the deidentified-randomized radiographs. They classified the TCF according to Rammelt classification(type1:extraarticular avulsion, type2:fracture with compromise of the incisura, type3: fracture with impaction of the anterolateral plafond), formulated a treatment (conservative/surgery), and if treated surgically, defined the patient positioning, type of fixation and surgical approach for the TCF. The same questions were answered after evaluating the CT-scans. Changes in surgical strategy after CT-scan evaluation were recorded. Forward stepwise regression was performed to determine which variables are associated with the change in operative planning. Interobserver agreement was calculated (Fleiss's Kappa coefficient).P-value < 0.05 was considered significant. Results: 1134 ankle fractures were evaluated. 481 fractures met the inclusion criteria, of which 83(17.3%) had a TCF. After CT-scan evaluation, the classification and conservative/surgical plan changed by 69.1% and 12.5%, respectively. When surgery was selected, the patient positioning, surgical fixation, and approach for the TCF changed by 32.1%,43.8%, and 35.3%, respectively.Regression analysis showed that the detection of TCF under CT-scan changes the conservative/surgical plan(OR 6.7, 1.7-25.9), and the type of fixation for TCF(OR 0.15, 0.1-0.4).Moreover, the change in the classification is a predictor of change in the surgical fixation(OR 8.1 3.0-21.7) and approach(OR 4.1, 1.7-9.9). Posterior malleolar fracture was the only predictor associated with the change in the patient positioning(OR 7.1, 2.1-23.9).The agreement between radiographs and CT-scans was moderate or less for the surgical strategy. Conclusion: The CT scan changes the type of surgical fixation and approach for TCF by 43.8% and 35.3%, respectively. Moreover, the detection of TCF or change in the classification are independent predictors of change in surgical strategy. To our knowledge, this is the largest series of patients demonstrating the importance of the CT scan in the operative planning of TCF during adulthood.