A Cadaveric Study: Does Ankle Positioning Impact the Quality of Anatomic Syndesmosis Reduction

Abstract The objective of this study is to determine whether the quality of syndesmotic reduction is influenced by ankle position. The investigators hypothesize that fixation with the ankle dorsiflexion results in significantly greater rates of syndesmotic malreduction compared to ankles fixed in resting plantarflexion position. Injuries to the syndesmosis are common, with incidence rates reported of 5-10% of all ankle sprains and 23% of ankle fractures. The ankle syndesmosis is crucial for maintaining joint congruence and normal tibiotalar contact mechanics during weight bearing. Therefore, injuries to the syndesmosis alter mechanics which may contribute to the development of post-traumatic osteoarthritis (PTOA). The current school of thought is the perform reduction and fixation in maximal ankle dorsiflexion. Nonetheless, the rate of syndesmotic malreduction remains high, ranging from 24% to 52%, despite treatment by experienced surgeons, leading to decreased patient reported outcome measurements and increased tibiotalar contact pressure. The proposed study would use cadaveric specimens to model syndesmotic disruption, with an injury computed tomography (CT) scan. Then each sample would undergo direct reduction using the relationship of the articular surface of the anterolateral distal tibia to the anteromedial fibular articular surface, fixation in maximum ankle dorsiflexion, followed by a post-fixation in dorsiflexion CT scan. The fixation would then be removed, the process would be repeated with direct reduction using the relationship of the articular surface of the anterolateral distal tibia to the anteromedial fibular articular surface, fixation in resting ankle plantarflexion, followed by a post-fixation in plantarflexion CT scan.