Effects of Three-Dimensional CT on Surgical Plans for Trimalleolar Ankle Fractures

Background: Three-dimensional CT (3D-CT) has enhanced medical imaging by producing detailed surface renderings from two-dimensional CT scans. As an advancement beneficial in orthopaedic trauma, 3D-CT offers improved visualization of fracture geometry, size, and spatial relationships. For trimalleolar ankle fractures, specifically, 3D-CT could refine surgical planning and classification. Multiple studies have investigated the effect of 3D-CT on various injuries, yet the effect on trimalleolar fractures remains underexplored. Methods: Our study examined the influence of 3D-CT on preoperative planning for trimalleolar ankle fractures, comparing it with preoperative planning using radiographs and CT. Patient records were reviewed from January 1, 2017, to May 24, 2021. Four orthopaedic surgeons analyzed preoperative imaging in two phases: initially with radiographs and CT and then with the inclusion of 3D-CT. Each reviewer then completed a questionnaire consisting of fracture classification and surgical planning questions. Statistical analysis was completed using Cohen kappa coefficient. Results: Analysis of 42 patient cases revealed notable differences in surgical approaches, posterior fixation methods, and fixation sequences when using 3D-CT (1- k > 0.70). Changes in Mason classification (1- k = 0.62) and order of lateral fixation (1- k = 0.67) approached significance; however, variability in intraobserver reliability was noted among reviewers. Conclusions: 3D-CT markedly influences preoperative planning for trimalleolar ankle fractures, specifically involving decisions about the posterior malleolus fragment. Future research should be aimed toward a comparison of preoperative planning with real-world surgical outcomes while also weighing the cost of 3D-CT. Level of Evidence: Diagnostic level III