An in Vitro Explant Model of Overuse Tendinopathy. the Effects of Cyclic Loading and Inflammatory Mediators on Mechanical and Compositional Properties of Tendons

AADITYA DEVKOTA: An In Vitro Explant Model Of Overuse Tendinopathy. The Effects of Cyclic Loading And Inflammatory Mediators On Mechanical And Compositional Properties of Tendon. (Under the direction of Paul Weinhold) Overuse injuries are common clinical problems, athletically and occupationally, with estimates that nearly 50% of all injuries are overuse. Though a major clinical issue, the underlying etiology of tendon overuse injuries is unknown. Currently, the prevailing thought centers on microdamage accumulation. This is where loading (well below failure levels) causes damage at the fibrillar level. When this damage outpaces the tendon’s ability to repair itself, then tendinopathy is thought to occur. The elastic limit beyond which this microdamage occurs has long been accepted at 4% strain. The first objective was to examine this idea utilizing newer methodologies by first loading tendons to various subfailiure strain levels, then loading to failure after rest. The elastic limit approached the failure strain limit (16%), implicating cellular responses as the driving factor in tendinopathy. To examine overuse tendinopathy, the next objective was to develop and characterize a model to apply and monitor complex, cyclic loadings to viable tendon. This device was able to significantly reduce the mechanical properties of loaded tendons (relative to control) as well as monitor this damage (strain accumulation).