Background: The stability of the syndesmosis is extremely important in terms of syndesmosis injury, ankle instability, and posttraumatic osteoarthritis development following ankle fractures. The aim of this study is to evaluate 1-year radiographic outcomes after posterior malleolar fixation in lateral and posterior malleolar fractures and trimalleolar fractures without transsyndesmotic screw fixation.
Methods: Ninety-four patients who underwent posterior malleolar fixation with posterolateral approach between January 2017 and June 2019 were evaluated retrospectively. The patients were evaluated with parameters such as demographic characteristics, fracture type, injury mechanism, physical examination, and radiographic measurements. The stability of the syndesmosis was evaluated by an intraoperative Cotton test and by measuring the tibiofibular overlap, tibiofibular clear space, and medial clear space parameters preoperatively on the immediate postoperative, first-year weightbearing ankle anteroposterior radiographs.
Results: In immediate postoperative measurements on radiographs, although the mean tibiofibular overlap (P < .001) increased, the mean tibiofibular clear space (P < .001) and mean medial clear space (P < .001) decreased compared with preoperative radiographs. Immediate postoperative mean tibiofibular overlap, tibiofibular clear space, and medial clear space compared with postoperative first-year mean tibiofibular overlap (P = .39), tibiofibular clear space (P = .23), and medial clear space (P = .43) were not statistically significant. Bone union was completed radiographically at a median of 3.4 ± 1.8 months after surgery.
Conclusion: After posterior malleolar fractures, anatomic reduction of the posterior malleolus and posterior inferior tibiofibular ligament complex provides strong syndesmosis stability as measured radiographically at 1 year. Patients may not need additional transsyndesmotic screw fixation.
Level of evidence: Level IV, case series.
Keywords: ankle; plate fixation; posterior malleolar fracture; posterolateral approach; syndesmosis injury.