Influence of Vertebra Stiffness in the Finite Element Analysis of the Intervertebral Disc

Spine finite element models are an essential tool to study the degeneration of the intervertebral disc (IVD). Due to the complex geometry of the vertebras, the anisotropy and heterogeneity of the tissues, and the contact and material nonlinearities [1], spine models demand high computational resources. Considering the relatively low stiffness of the IVD compared to that of the vertebrae, we hypothesized that finite element stress and stress distributions of the IVD do not change substantially if the vertebras are modeled as rigid bodies. This simplification in spine models may considerably reduce the solution time when the interest is the analysis of the IVD.