Computed Tomography Scans and Fixation Rates for Trimalleolar Ankle Fractures Over 10 Years at a Level 1 Trauma Center

Background: The posterior malleolus component of the trimalleolar ankle fracture has posed a controversial topic for diagnostic imaging and surgical management. Preoperative computed tomography (CT) scans are used to better appreciate fracture morphology and may affect management techniques. No prior study has investigated the trend in preoperative CT scan use and the rates of posterior and syndesmotic fixation for trimalleolar injuries.

Methods: This retrospective cohort study evaluated the use of preoperative CT scans and the rates of posterior and syndesmotic fixation for trimalleolar ankle fractures over a 10-year period at an adult level 1 trauma center. Patients surgically managed for ankle fractures with OTA/AO classifications of 44B3, 44C3.3, 44C1.3, 44C2.3, and 44A3 were identified and included using Current Procedural Terminology codes and a prospectively collected fracture registry. Demographic information, comorbidities, fixation methods, and use of preoperative CT scan were recorded. Comparative analyses were performed to assess for yearly differences in demographic characteristics along with changes in trends of preoperative CT scans and posterior and syndesmotic fixation.

Results: A total of 1191 patients were included in the analyses. OTA/AO 44B3.2 fractures were the most common injuries (yearly range of 59.4%-80.1%). The rate of posterior fixation did not significantly increase during the study interval (1.4% growth per year [95% CI -0.27, 3.07]). However, the rate of preoperative CT scan use significantly increased by 2.76% (95% CI 1.99, 3.52) per year and the rate of syndesmotic fixation increased by 2.58% (95% CI 1.17, 3.99) per year. Fixation methods for both the syndesmosis and posterior malleolus changed during the study timeline.

Conclusion: Despite a relatively stable rate of posterior fixation, the frequency of preoperative CT scans and use of syndesmotic fixation increased significantly over a 10-year study period.

Level of evidence: Level IV, descriptive pilot study.