Traction-induced Injury of Rat Achilles\u27 Tendon: New in Vivo Biomechanical Model for the Assessment of Tendon Disease and Injury

The goal of this project is to advance the understanding of tendon disease and injury through the design and validation of a new model of tendon injury. Controlled, mechanically-induced traction injury was created in rat Achilles’ tendons with a tensioning apparatus through a minimally invasive surgical approach. Tendons were tensioned to subailure loads. Assessments of damage to tendons included gross morphology, evaluation of biomechanical of load strain curves, histopathology under light microscopy (H&E), collagen fibril structure and disruption under scanning electron microscopy, and immunohistochemical study of MMP-13 expression under confocal laser microscopy. Tendon injuries were found to be more severe with respect to loads placed upon them. Differences between treatment groups were identified subjectively in microscopic appearance (H&E), in collagen fibril organization (SEM), and in MMP-13 expression. However, analysis of the numerical data did not provide definitive evidence that this model for acute tendon injury is consistent and repeatable