Biomechanical Evaluation of the Sheep Common Peroneal Nerve After Crush Injury

Axonotmesis, a common peripheral nerve injury in humans and animals, leads to significant biomechanical and physiological consequences. The lack of a standardized crushing protocol for complex animal models limits research and therapeutic translations for humans and clinically relevant animal species. This study aimed to assess the impact of different crushing forces on the biomechanical behavior of the sheep common peroneal nerve and to establish a force for standardized in vivo protocols. Fourteen nerves of equal length were harvested and preserved and their initial diameter measured. They were subjected to crushing forces of 0 N, 80 N, and 180 N for one minute. Post crushing, the diameter, ultimate tensile strength, displacement at rupture, stress, strain, and stiffness were evaluated. Results showed that increasing crushing forces significantly affected nerve biomechanical parameters. Nerves crushed with 180N displayed lower tensile strength, displacement, and stiffness but higher stress and strain, indicating greater physical damage and structural degradation. These findings suggest that 180N induces substantial nerve fiber rupture and disruption of nerve trunk support elements, making it a candidate force for an axonotmesis protocol in the ovine model. Future in vivo studies should validate its effectiveness in creating complete crush injuries with functional and histological consequences, facilitating protocol standardization and translational research.