A Cadaveric Study: Does Deltoid Ligament Repair Impact the Quality of Syndesmotic Reduction?

Abstract

Objectives: To compare the quality of syndesmotic reduction with and without deltoid ligament repair (DLR).

Methods: Ten cadaveric ankle specimens underwent baseline computed tomography (CT) imaging in neutral plantarflexion. A fellowship-trained orthopaedic trauma surgeon disrupted the syndesmosis and deltoid ligament of each specimen. The syndesmosis was reduced in neutral plantarflexion by manual hand pressure under direct visualization through an anterolateral approach and stabilized with two 0.062-inch K-wires placed lateral-to-medial in a quadricortical fashion. Postreduction CT imaging was then obtained. K-wires were removed, and DLR was performed using suture anchor fixation. The syndesmosis was again reduced and stabilized using the same technique, followed by a second postreduction CT scan. Four validated measurements were used to evaluate the quality of syndesmotic reduction. All postreduction CT scans were compared to baseline using mixed-effects linear regression to account for the nesting of ankles within donors.

Results: Ten cadaveric ankle specimens were obtained from five donors (mean age: 76.8 years [range: 70-83 years], 3 female and 2 male). Postreduction CT imaging demonstrated mean anterior translation of the fibula, both with DLR compared to baseline (6.4±1.1 mm vs. 7.7±1.5 mm, P=0.001) and without DLR compared to baseline (6.4±1.9 mm vs. 7.7±1.5 mm, P<0.001). The fibula was internally rotated following DLR when compared to baseline when evaluating mean rotation ratio (0.3±0.1 vs. 0.4±0.2, P=0.04) but not mean rotation angle (15.4±3.9 degrees vs. 13.3±3.2 degrees, P=0.12). No differences were observed in mean lateral translation with or without DLR compared to baseline (P>0.05). Direct comparison of reductions with and without DLR showed no differences in measures of mean reduction quality (P>0.05).

Conclusions: In this cadaveric study, DLR did not significantly improve syndesmotic reduction quality compared to reductions performed without DLR. Relative internal rotation of the fibula was observed after DLR, perhaps due to prevention of talar external rotation and tensioning of the medial side during syndesmotic reduction.