Tricortical versus quadricortical syndesmosis fixation in ankle fractures - A prospective, randomized study comparing two methods of syndesmosis fixation

Objective: To assess short-term functional results in 2 types of syndesmotic fixation, comparing the traditional rigid quadricortical syndesmotic screw fixation with a more dynamic tricortical screw fixation. Design: Prospective, randomized clinical study. Setting: University clinic, level 1 trauma center. Patients: Sixty-four patients with closed ankle fractures in which the syndesmosis was found to be unstable intraoperatively. Intervention: The unstable syndesmoses were fixed with either one 4.5-mm cortical screw through both tibial cortices (n = 30) or two 3.5-mm cortical screws engaging only 1 cortex of the tibia (n = 34). The quadricortical screws were routinely removed after 2 months, whereas the tricortical screws were removed only in the case of discomfort. Rehabilitation was the same in both groups. Results: The Olerud Molander functional score (0-100) was significantly higher in the tricortical group (77 points) compared with the quadricortical group (66 points) (P = 0.025) at 3 months. After I year, however, the functional score was not significantly higher (P = 0.192) in the tricortical group (92.6 points) compared with the quadricortical group (85.7 points). Pain was significantly lower in the tricortical group (P = 0.017) after 3 months, but there was no significant difference after 1 year. There was no significant difference in dorsiflexion between the groups at any point of time. No losses of fixation were detected. The tricortical screws were removed in 2 patients due to migration. Conclusions: Syndesmosis fixation with 2 tricortical screws is safe and improves early function. After 1 year, however, there were no significant differences between the 2 groups in functional score, pain, and dorsiflexion.