JAAOS - 2026-07-15 - Journal Article
Effects of Three-Dimensional CT on Surgical Plans for Trimalleolar Ankle Fractures.
Robbins JB, Meshay I, Horn KJ, Jupiter DC, Lindsey RW, Chen J, Panchbhavi VK, Hagedorn JC
Topics
Key Takeaway
Adding 3D-CT to standard radiographs and CT changed surgical approach, posterior fixation method, or fixation sequence in trimalleolar ankle fracture planning with interobserver agreement exceeding kappa 0.70 for those three domains.
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Summary
Four orthopaedic surgeons reviewed preoperative imaging for 42 trimalleolar ankle fractures in two sequential phases—radiographs plus CT alone, then with 3D-CT added—completing standardized questionnaires on fracture classification and surgical planning. Addition of 3D-CT produced clinically meaningful changes in surgical approach, posterior fixation method, and fixation sequence (1-[k] >0.70). Mason classification changes and lateral fixation order approached but did not reach the same agreement threshold (1-[k] 0.62 and 0.67, respectively), with notable intraobserver variability among reviewers.
Key Limitation
Planning changes were never validated against actual surgical execution or patient outcomes, so the clinical significance of the observed kappa differences remains speculative.
Original Abstract
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.