Volume 1, Issue 5, February-March, 2017

Pages: 126-134 DOI: https://doi.org/10.24243/JMEB/1.5.308

Composite mechanics of the multilayer structure of the annulus fibrosus

Author: G Youssef, C Lopez, JM Kabo

Category: Biomechanics

Abstract:

The degeneration of the intervertebral disc (IVD) rests on many factors, but some of the main ones are the absence of a blood vessel supply, excessive overloading, and cycling loadings. This deterioration may contribute to peripheral pain and neurological dysfunctions. When degeneration is severe or in some other cases when the annulus fibrosus (AF) ruptures, fusion surgery, disc arthroplasty, and disc discectomy have been used as clinical solutions. However, these solutions limit the range of motion, the material used does not reproduce the natural behavior, and more importantly, it weakens the overall mechanical response of the spinal column, which accelerates degeneration. Recent research indicates a new focus on the composite nature of the annulus. In this paper, a mathematical model is used to predict the mechanical behavior of the AF based on its anatomical structure. Previously published experimental data of AF are correlated with the mechanistic-based predictions and found to be in good agreement. The mathematical model shows that maximum strain occurs at the mid-to-outer region, which is consistent with published data from animal models. The results indicate that future motion preserving, total disc replacement devices and tissue restoration technology can be effectively designed using composite materials for synthetic AF. DOI:https://doi.org/10.24243/JMEB/1.5.308

Keywords: composite mechanics, intervertebral disc, annulus fibrosus, mechanical behavior of annulus, disc mechanics, disc degeneration