Comparison of Different Fixation Methods of the Suture-Button Implant for Tibiofibular Syndesmosis Injuries

Abstract

Background: Suture-button fixation for tibiofibular syndesmosis injuries is a relatively new surgical technique thought to provide semirigid dynamic stabilization. However, adequate information is still not available and there are controversies as to whether it provides enough fixation for syndesmosis injuries. Hypothesis: Optimally directed suture-button fixation brings physiologic dynamic stabilization of the ankle syndesmosis. Study Design: Controlled laboratory study. Methods: Stabilization of the ankle syndesmosis fixed by a suture-button construct was examined using 6 normal fresh-frozen cadaver legs. After initial tests of intact and injured models, suture-button fixation and screw surgical techniques were performed sequentially for each specimen, with single suture-button fixation, double suture-button fixation, anatomic suture-button fixation, and metal screw. Anterior and medial traction forces, as well as external rotation force, were applied to the tibia; the diastasis of the syndesmosis and the rotational angle of the fibula related to the tibia were measured using a magnetic tracking system. Results: Each traction and rotation force significantly increased the diastasis and fibular rotational angles in the created injury models. With single fixation, the diastases increased significantly compared with the intact model with an anterior traction force ( P < .001), a medial traction force ( P = .005), and an external rotation force ( P = .015). The fibular rotational angles increased significantly with a medial traction force ( P = .005) and an external rotation force ( P < .001). With double fixation, the diastases increased significantly with a medial traction force ( P = .004) and an external rotation force ( P = .012). The fibular rotational angles increased significantly with a medial traction force ( P = .035) and an external rotation force ( P = .002). With anatomic fixation, there were no significant differences compared with the intact model. With the metal screw, the diastases decreased significantly with an external rotation force ( P = .037). Conclusion: Neither single nor double fixation for syndesmosis injuries provided multidirectionally stabilizing syndesmosis. Anatomic fixation directed from the posterior cortex of the fibula to the anterolateral edge of the tibia allowed dynamic stabilization of intact cadaver specimens. The metal screw provided very rigid fixation. Clinical Relevance: Optimal direction of the suture button can provide adequate stabilization of the ankle and could benefit athletes with syndesmosis injuries.