REDISTRIBUTION OF LOAD OF INJURED LOWER CERVICAL SPINE UNDER AXIAL COMPRESSION USING FEM

Abstract

In human spine, any ligamentous injury, degenerated disc or facetectomy leads to certain degrees of spinal instability. There are limited studies using finite element method (FEM) simulating these effects to evaluate the biomechanical response of spine under various physiological load configurations. This parametric study was conducted to evaluate the roles of ligaments, facets, and disc nucleus in the transmission of load from superior to inferior vertebral level of human lower cervical spine (C4-C6) using the FE approach. Accordingly, a 3-dimensional FE model of the C4-C6 cervical spine, consisted of 11,187 nodes and 7,730 elements modeling the bony vertebrae, articulating facets, intervertebral dies, and associated ligaments, was developed and its predicted results were validated against published data under axial compression load configurations. The FE model was further modified accordingly to investigate the role of disc, facets and ligaments in preserving cervical spine motion segment stability under same load configuration. The passive intact FE model predicted the non-linear force displacement response of the human cervical spine, with increasing stiffness at higher loads. The simulated injured models predicted the role of ligaments, facets or disc nucleus in preserving the cervical spine stability in term of redistribution of load.