Deltoid ligament repair versus trans-syndesmotic fixation for bimalleolar equivalent ankle fractures

Abstract

Introduction: The role of deltoid ligament repair is controversial in the treatment of bimalleolar equivalent ankle injuries. Our purpose was to compare midterm functional outcomes and reoperation rates of unstable distal fibula fractures treated with open reduction internal fixation (ORIF) of the fibula and either deltoid ligament repair, trans-syndesmotic fixation, or combined fixation.

Methods: Skeletally mature subjects were retrospectively identified after fixation of isolated unstable distal fibula fractures treated at a single academic level 1 hospital from January 2005 to May 2019. The AAOS Foot and Ankle Module outcomes questionnaire (AAOS-FAM) was obtained at a mean time from surgery of 4.6 +/- 3.1 years. Subjects underwent one of three methods of fixation including distal fibula ORIF and one of the following: trans-syndesmotic fixation (N = 66), deltoid ligament repair (N = 16), or combined trans-syndesmotic fixation and deltoid ligament repair (N = 26). Outcomes scores and Charlson Comorbidity Index scores were compared between groups by Kruskal-Wallis testing for non-normally distributed data. Rates of reoperation were compared by Fisher's exact test. Statistical significance was set to P < 0.05 for all comparisons.

Results: There was no significant difference in AAOS-FAM scores between the three groups (P = 0.18). No subjects in the deltoid ligament repair group underwent reoperation compared to 17 (26%) in the trans-syndesmotic fixation group and six (23%) in the combined fixation group. The most common reason for reoperation was removal of hardware, which was performed in 12 (18%) subjects in the trans-syndesmotic fixation group and three (12%) subjects in the combined fixation group.

Conclusions: Direct deltoid ligament repair yields similar functional scores and fewer reoperations compared to trans-syndesmotic fixation at midterm follow up. Deltoid ligament repair may be a favorable treatment strategy when considering trans-syndesmotic fixation in the surgical treatment of unstable distal fibula fractures.

Keywords: Ankle fracture; Deltoid ligament repair; Syndesmosis; Trans-syndesmotic fixation.