| A three dimensional finite element program for a spinal motion segment (SMS) has been developed in this study to investigate the failure mechanism in an intact SMS as well as in a degenerated SMS. Some important aspects considered in the development of the finite element model includes: the in vivo geometry of a SMS from CT scans, the nucleus pulposus as inviscid incompressible fluid, the annulus fibrosus as composite fiber-reinforced material, the ligaments as nonlinear axial springs, and the facet joints as nonlinear interface moving contact surfaces.;The current study has provided information regarding the mechanical behaviors and the failure mechanism for an intact and a degenerated SMS. This study examined the most common physiological loading conditions which occur in daily activities and incorporated the most common degenerative changes that are observed in intervertebral discs. |
