SLR - January 2022 - Olivia K. Hammond

Suture Button Versus Syndesmosis Screw Fixation in Pronation-External Rotation Ankle Fractures: A Minimum 6-Year Follow-Up of A Randomised Controlled Trial

Reference: Lehtola, R., Leskelä, H.-V., Flinkkilä, T., Pakarinen, H., Niinimäki, J., Savola, O.,  Kortekangas, T. (2021). Suture Button Versus Syndesmosis Screw Fixation in Pronation-External Rotation Ankle Fractures: A Minimum 6-Year Follow-Up of A Randomised Controlled Trial. Injury. 2021 Oct;52(10):3143-3149

Level of Evidence: II

Scientific Literature Review

Reviewed By: Olivia K. Hammond, DPM
Residency Program: Inova Fairfax Medical Campus – Falls Church, VA

Podiatric Relevance: Addressing syndesmotic instability is a key part in the surgical management of ankle fractures. Although syndesmotic screw (SS) fixation has traditionally been considered the gold standard, flexible fixation with suture button (SB) is also commonly used for repair. Short-term studies have suggested an advantage with flexible fixation when it comes to radiographic and functional outcomes. However, long-term data comparing the two techniques is lacking. In this study, authors assess the maintenance of syndesmotic reduction in flexible vs screw fixation, after a minimum of six years.

Methods: Patients with Lauge-Hansen pronation-external rotation (PER) type 4/Weber C ankle fractures between January 2010 and December 2011 were evaluated. Forty-three patients were included. Twenty-two were randomized into the SS group and twenty-one were placed in the SB group. Those in the SS group were fixed with a single 3.5-millimeter fully-threaded tricortical screw and those in the SB group were fixed using an Arthrex Tightrope®. Intra-operative computed tomography was used on bilateral ankles after syndesmotic fixation to compare the uninjured side. Standing cone-beam computed tomographies (CBCTs) were used at three and seven years post-operatively to measure syndesmotic reduction and severity of ankle osteoarthritis (OA).

Results: The average follow up was 7.1 years. There were no significant differences between the groups for syndesmotic reduction, development of OA, or functional outcomes. Two patients in the SS group and one in the SB group developed a malreduced syndesmosis (P = 0.58). In both fixation groups, a more severe grade of OA occurred in the injured ankle vs the contralateral limb at the seven-year follow up (P=0.11). The mean Olerud-Molander Ankle Outcome Score (OMAS) was 88 in the SS group and 78 in the SB group (P=0.32).  

Conclusions: Flexible suture button and screw fixation techniques were equivocal for maintenance of syndesmotic reduction in PER4 fractures over a long-term follow up.  Although post-traumatic OA is common in PER4 injuries regardless of fixation, patients still had mostly good to excellent functional outcomes. A lengthier follow up may be beneficial to investigate the development of OA after ankle fractures with associated syndesmotic injuries. This report underscores that there is no significant difference in outcomes relative to syndesmotic fixation selection and therefore, fixation selection should be based upon surgeon preference and understanding risks and needs for potential re-operation with SS placement.

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