Biomechanical behavior of the human C4-C6 cervical motion segment under axial compression

Based on the 3-D CT scanning image of the human cervical spine, we develop a detailed and anatomically accurate human cervical finite element model for the C4-C6 motion segment to investigate the biomechanical properties of the cervical spine under axial compression. This model includes the vertebrae, intervertebral disc and various ligaments. In this paper, the annulus fibrosus in the intervertebral disc is modeled by using a nonlinear, hyperelastic fiber reinforced model with fiber-matrix shear interaction developed by Peng et al in Reference[9]. Other materials in the cervical motion segment are simplified as linear elastic. In the axial compression simulation, the numerical force-displacement relationship from the finite element analysis is compared with experimental data available in the literature and a good agreement is obtained. It is found that the posterior intervertebral annulus fibrosus has the most distinct stress variation during compression. The results and findings obtained in this paper are very helpful in the diagnosis and therapy of clinical cervical spine instabilization and disc degeneration.