Radiological comparison of isolated syndesmotic screw fixation and transplate syndesmotic screw fixation in distal tibiofibular syndesmotic injuries

Purpose The purpose of the study is to compare isolated syndesmotic screw fixation and transplate syndesmotic screw fixation in distal tibiofibular syndesmotic injuries. Methods In this retrospective study, 37 patients diagnosed with pronation-external rotation ankle fractures requiring screw fixation were enrolled between July 2023 and December 2024. Nineteen patients underwent isolated syndesmotic screw fixation. Another group of 18 patients received transplate syndesmotic screw fixation. Follow-up was conducted for a minimum duration of 12 months. Radiographic outcomes were assessed using CT scans and x-rays. The CT evaluations included measurements of screw entry point and trajectory, anterior tibiofibular distance, posterior tibiofibular distance, anteroposterior fibular translation, and fibular rotation, conducted within 24 h post-operation and at one year after syndesmotic screw removal. x-ray assessments focused on tibiofibular overlap, tibiofibular clear space, and medial clear space, also evaluated at the same time nodes. Results Preoperative and intraoperative data, including age, sex, time from injury to surgery, and mean operating time, were comparable between the two groups ( p 0.05). Significant differences were observed in the screw entry points and trajectories ( p 0.05) between the groups. Postoperative ankle x-rays showed no significant differences in syndesmotic reduction quality between the groups ( p 0.05). However, postoperative immediate CT scans indicated that the transplate syndesmotic screw fixation group experienced a higher incidence of posterior tibiofibular distance widening ( p 0.05). The 12-month postoperative ankle CT scans showed that in both groups, patients with mild ankle malreduction or overtightening of distal tibiofibular syndesmosis almost achieved spontaneous reduction after the removal of the distal tibiofibular syndesmotic screws, while patients with severe malreduction or syndesmotic widening still exhibited persistent distal tibiofibular syndesmotic malreduction. Conclusions According to radiological comparisons, the fibular plate may interfere with screw placement and increase the likelihood of malalignment of the distal tibiofibular syndesmosis.