# Biomechanical Evaluation of the Sheep Common Peroneal Nerve After Crush Injury

## TL;DR

This study identifies 180 N as the optimal force to create consistent nerve damage in sheep, helping standardize research on nerve injuries for better human and animal treatments.

## Contribution

The study establishes a standardized crush force protocol for sheep nerves to model axonotmesis injuries.

## Key findings

- Higher crushing forces caused greater nerve damage, reducing strength and flexibility.
- 180 N was identified as the most effective force for inducing consistent nerve injury in sheep.
- Nerves crushed with 180 N showed higher stress and strain, indicating structural degradation.

## Abstract

Axonotmesis, a type of nerve damage caused by crushing, often leads to severe consequences in humans and animals. However, the lack of a standardized method for creating crush injuries in animal models makes it difficult for researchers to compare results and develop effective treatments for both humans and animals. This study explored how different levels of force affect the behavior of sheep nerves, aiming to establish a reliable protocol for future research. Nerves were collected, measured, and subjected to various crushing forces for one minute. Afterward, researchers measured their strength, flexibility, and structural changes. The results showed that higher forces caused more significant damage, reducing the strength and flexibility of the nerves while increasing the stress they could endure before breaking. The study identified 180 N as the most effective force to create consistent nerve damage, making it suitable for use in live animal studies. This research will help standardize methods for studying nerve injuries, improving the ability to test new treatments and potentially benefiting people and animals suffering from nerve damage. Standardized methods like this are essential for advancing medical and veterinary treatments applied to peripheral nerve regeneration.

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.