Strain Distribution in the Anterior Inferior Tibiofibular Ligament, Posterior Inferior Tibiofibular Ligament, and Interosseous Membrane Using Digital Image Correlation:

Background:Ligament repair and augmentation techniques can stabilize syndesmosis injuries. However, little is known about the mechanical behavior of syndesmotic ligaments. The aim of this study was to analyze full-field strain, strain trend under foot rotation, and subregional strain differences of the anterior inferior tibiofibular ligament (AITFL), posterior inferior tibiofibular ligament (PITFL), and interosseous membrane (IOM).Methods:Eleven fresh-frozen lower limbs were dissected to expose the AITFL, PITFL, and IOM. The foot underwent rotation from 0° to 25° internal and 35° external, with 3 ankle positions (neutral, 15° dorsiflexion, and 25° plantarflexion) and a vertical load of 430 N. Ligament strain was recorded using digital image correlation.Results:The mean strain on the AITFL with 35° external rotation was greater in the proximal portion compared with distal portion in the neutral position (P = .009) and dorsiflexion (P = .003). The mean strain in the tibial insertion and midsubstance near ti...