Development and Validation of a Three-Dimensional Nonlinear Finite Element Model of the C4-C6 Cervical Spine Unit

Finite element (FE) analysis is a tool that can be used to investigate the mechanics of complex structures such as the cervical spine. FE analysis of the cervical spine is useful for predicting values that might be difficult or impossible to measure experimentally. Advanced computer techniques are required to generate a FE model of such a complex structure in an efficient and accurate manner. This study developed and verified techniques to generate and solve a three-dimensional nonlinear FE model of the cervical spine C4-C6 structure. These techniques were designed with the following objectives in mind: 1. The FE model would accurately simulate the force transmission through the structure of the cervical spine. This would be measured by comparing the force-deflection curves for each load case from this FE model with those . from experimental studies. 2. The FE model of the vertebrae of the cervical spine would be represented by eight node solid hexahedral elements that closely match the original surface geometry of the cervical spine specimen used in this study. This is important because the joints, through which all the forces get transmitted, have complex surfaces. Thus, to correctly simulate the directions of these transmitted forces from vertebra to vertebra the surfaces must be accurately represented. In addition, this model will be used in later studies to simulate clinical cervical spine surgical procedures. The ability to simulate these procedures would be enhanced if the geometry of the FE model matched the actual geometry of the cervical spine. The medical doctors would also trust the results more if the FE model looked visually realistic to them..