Does repair of deltoid ligament contribute to restoring a mortise in SER type IV ankle fracture with syndesmotic diastasis?

Purpose To analyze the radiographic and clinical outcomes of deltoid ligament repair, we studied 34 supination external rotation type IV ankle fracture patients with deltoid ruptures who required syndesmosis fixation. Methods We retrospectively evaluated 34 cases of ruptured deltoid ligaments with associated supination external rotation type IV ankle fractures with a widening of the syndesmosis between 2011 and 2017. All of the ankle fractures were treated with a similar surgical protocol (plate and screw fixation). Syndesmotic fixations were performed on all patients. The deltoid ligaments were surgically repaired in 19 patients and in 15 patients, they were not. The preoperative, immediate postoperative, and final follow-up radiographic outcomes (medial clear space, overlap space, and clear space) and clinical scores (Foot and Ankle Outcome Scores and the Foot Function Index) were compared. Patients were followed for an average of 13.6 months. Results There was no significant difference in radiographic and clinical outcomes between the deltoid repair group and the unrepair group (P > 0.05). In both groups, the mean immediate postoperative radiographic outcomes were satisfactory, showing reduced MCS, reduced CS, and increased OS to within-normal ranges that were maintained at the final follow-up. Clinical outcomes were similar between the two groups (P > 0.05). The rate of complications, such as intra-articular lesions, malunions, nonunions, and arthrosis was comparable between the two groups. Conclusion In both groups, the postoperative and final follow-up radiographic measures were within normal ranges and the radiographic and clinical outcomes were not significantly different between the two groups. Syndesmotic reduction could be much more important than deltoid repair in regard to mortise restoration and medial stability.