Study of the influence of structural features of intervertebral disk on its stress-strain state

The article presents the model of intervertebral disc, that takes into account the presence of a nucleus pulposus and an annulus fibrous containing collagen fibers with direction at angles ±45° and ±30°. The influence of the percentage of layers of the annulus fibrous with different directions of collagen fibers on the stress-strain state of the intervertebral disc was investigated. The increase in the percentage of layers in the annulus fibrous with a fiber direction of ±45° leading to an increase in stresses and deformations was revised, both in the nucleus pulposus and in the adjoining layers of the annulus fibrous. Exceptions are the stresses of the adjoining layers of the annulus at 100% direction of the fibers at angles of ±45°.