Sensibility analysis of the material properties applied to an intervertebral disc model

The intervertebral disc is the structure that lies between adjacent vertebrae in the spine; is composed by an annulus fibrosus and a nucleus pulposus, and work as a shock absorber. The annulus fibrosus consist of concentric layers of collagen type I and II, the nucleus pulposus is composed of type II collagen and water. In biomechanical studies of the spine the selection of proper material properties, to be used for computational models, is important due to their complexity. There are assorted values for these properties used by different authors in the literature. In this sense, the present work presents a sensitivity study of the stress analysis using a range of the properties commonly found in the literature for an isotropic and parametric intervertebral disc model. The aim of this study is determining which properties produce the most representative intervertebral behavior response to be subsequently applied in a more complex vertebral model.