A Cadaveric Assessment of the Deltoid Ligament in Transsyndesmotic Ankle Injuries

Transsyndesmotic ankle injuries lead to high rates of post-traumatic arthritis, despite appropriate methods of fixation. Current treatment involves syndesmotic screws or suture button fixation. Deltoid ligament repair has been considered an additional treatment option. The purpose of this study was to understand the role of the deltoid ligament in the context of syndesmotic instability, and the effect of deltoid ligament repair on ankle and syndesmotic biomechanics in a cadaveric model. Deltoid ligament repair in isolation was additionally compared to current fixation methods. The deltoid ligament serves as an indirect stabilizer of the syndesmosis in flexion and rotation. Sectioning the deltoid ligament destabilizes the tibiotalar joint, leading to increased ankle motion and decreased stiffness. Deltoid ligament repair reduces rotational tibiotalar motion and is equivalent to screw fixation. Combined deltoid ligament repair and syndesmotic screw fixation is the most biomechanically stable construct. The clinical implications of deltoid ligament repair require further study.