Interlamellar matrix governs human annulus fibrosus multiaxial behavior

Area of Science:

• Biomechanics and Biomaterials Science
• Computational Biology and Spine Research

Background:

• Accurate structure-property relationships for intervertebral disc annulus fibrosus are crucial for reliable human spine computer simulations.
• The tissue's multiaxiality, anisotropy, and regional dependency present significant challenges to existing modeling approaches.

Purpose of the Study:

• To develop a simplified hybrid experimental/modeling strategy for predicting the multiaxial response of human intervertebral disc annulus fibrosus.
• To establish a trans-species approach adapting animal disc models to human disc characteristics.

Main Methods:

• A novel hybrid microstructure-based experimental and modeling strategy was employed.
• The approach utilizes uniaxial circumferential response data from two different animal disc regions.
• This allows prediction of the multiaxial response for any human disc region.

Main Results:

• The study demonstrates the critical role of the interlamellar matrix in the disc's multiaxial response.
• The trans-species strategy successfully predicts multiaxial responses based on limited uniaxial data.
• The developed approach shows significant predictive capabilities for human disc behavior.

Conclusions:

• A simple hybrid strategy enables accurate prediction of human annulus fibrosus multiaxial response.
• This method highlights the interlamellar matrix's importance in disc mechanics.
• The approach offers a promising tool for long-term human spine computer simulations and predictions.