Syndesmotic Injury Assessment With Lateral Imaging During Stress Testing in a Cadaveric Model

Background:External rotation, lateral, and sagittal stress tests are commonly used to diagnose syndesmotic injuries, but their efficacy remains unclear. The purpose of this study was to characterize applied stresses with fibular motion throughout the syndesmotic injury spectrum. We hypothesized that sagittal fibular motion would have greater fidelity in detecting changes in syndesmotic status compared to mortise imaging.Methods:Syndesmotic instability was characterized using motion analysis during external rotation, lateral, and sagittal stress tests on cadaveric specimens (n = 9). A progressive syndesmotic injury was created by sectioning the tibiofibular and deltoid ligaments. Applied loads and fibular motion were synchronously measured using a force transducer and motion capture, respectively, while mortise and lateral radiographs were acquired to quantify clinical measurements. Fibular motion in response to these 3 stress tests was compared between the intact, complete lateral syndesmotic injury and l...