A three-dimensional Finite Element Analysis of the Lumbar Spine.

To understand the mechanial charasteristics of vertebral body structures, especially the effect of posterior elements, a stress analysis of the lumnbar spine was performed using the three dimensional finite element method. The FEM model contained two adjacent vertebre and the intervertebral disc, the structures of which were cortical bones, cancellous bones, annulus fibrosis, nucleus pulposus and ligament. We made three models which had different facetal angles. Compulsory displacement was applied to the models and the stresses and displacements were computed using the FEM program. The model which had larger facetal angle revealed bigger displacement.