In a totally unstable cadaver model, researchers for a study sought to arthroscopically evaluate syndesmotic stability following fixation with various combinations of suture buttons (SBs) and suture tape reinforcement. About 15 cadaver above-knee specimens were transection and fixed sequentially to create six experimental models: intact model, after complete disruption of the syndesmotic ligaments and repair with either suture tape reinforcement, suture tape reinforcement with a single SB, suture tape reinforcement with two diverging SBs, or two diverging SBs alone. Anterior and posterior tibiofibular spaces were measured arthroscopically under 100 N coronal stress, tibiofibular anteroposterior and posteroanterior translation in the sagittal plane was measured arthroscopically under 100 N sagittal stress, and anterior tibiofibular space was measured directly with a calliper under 7.5 Nm external rotation torque. The Wilcoxon signed-rank test was used to compare stability metrics given after each fixation procedure to the undamaged model and the whole unstable model.
Fixation with one SB and singular suture tape reinforcement augmentation produced stability comparable to the intact stage (coronal anterior space 1.24 vs. 1.15, P=0.887; coronal posterior space 1.63 vs. 1.64, P=0.8421; anteroposterior translation 0.91 vs. 0.46, P=0.003; posteroanterior translation 0.51 vs. 0.57, P=0.051; external rotation anterior tibiofibular space 1.08 vs. 0.55, P=0.069). Furthermore, adding a second SB improved fixation stability even further Although one or two SBs are insufficient to stabilize a destabilizing syndesmotic injury involving the anterior inferior tibiofibular ligament, interosseous ligament, and posterior inferior tibiofibular ligament, the addition of a suture tape reinforcement to even one SB restores syndesmotic stability to preinjury levels.