A Biomechanical Analysis of Ankle Instability in Supination External Rotation Ankle Fractures:

摘要

Category:TraumaIntroduction/Purpose:Supination external rotation (SER) 2 and SER3 ankle injuries are thought to be stable whereas SER4 injuries are thought to be unstable. In other words, deltoid rupture is thought to be a necessary component of instability in SER injuries. However, biomechanical evidence has shown that as little as 1 mm talar shift results in 40% loss in contact area leading to increased contact forces. Additionally, the external rotation stress exam which is the typical test used to detect instability is poorly standardized in the literature limiting its ability to detect subtle instability. Therefore the purpose of this study is to analyze talar rotation and translation with external rotation stress specifically in SER2 and SER3 patterns in an effort to better define which injury patterns are unstable.Methods:19 legs disarticulated below the knee were obtained. Optotrak optoelectronic 3D motion measurement system was used to determine positioning of the talus compared to the tibia. Spe...