Poster 1: Cell and Tissue Studies
Tendon Overload Using A Rodent Model Of Synergist Ablation Leads To Mechanical Degeneration
Lily M. Lin, Ellen T. Bloom, John M. Peloquin, Michael H. Santare, Justin Parreno, Karin G. Silbernagel, Dawn M. Elliott
University of Delaware
Introduction: Many tendon disorders are related to overloading, not overuse, thus, we recently established a rodent overload model of synergist ablation (SynAb). We showed multi-scale structural changes that suggest tendon degeneration, however, it was unclear whether the degeneration was induced exclusively from structural changes. Therefore, the objective of this study was to investigate the mechanical changes induced by tendon overload.
Methods: Bilateral plantaris tendons from 7-month-old female Long Evans rats were randomly assigned to two groups: SynAb and Control. At 8 weeks post-surgery, rats were sacrificed and the plantaris tendons were dissected. Each tendon underwent stress relaxation at 25% then a ramp to failure. All loading and unloading rates were 1%/s. The stress-strain curves were analyzed for transition point, yield point, failure point, and linear region modulus.
Results: The modulus and transition stress in SynAb was lower than Control. Yield and failure strain were not statistically different between the treatment groups, however, the SynAb yield stress was 52% lower than Control, and the SynAb failure stress was 65% lower than Control.
Conclusion: This study showed degenerative mechanical changes, specifically, we observed a decrease in modulus in the SynAb group indicating that increasing mechanical load from SynAb impairs mechanical function.
Research Area: Ligament & Tendon