软骨终板退化对颈椎椎间盘物质运输和力学响应的影响

The fluid flow in the cartilage endplate (CEP) is the main path of nutrient supply and metabolic waste transport within the intervertebral disc (IVD). The increased stiffness, the decreased permeability and the water content of the degenerated cartilage endplate influence the mechanical responses and material trans⁃ port within the IVD. A porous finite element model for C5⁃C6 of the cervical spine was established based on the computed tomography (CT) images of an adult. After validation, loads of compression, flexion, extension, ax⁃ ial rotation and lateral bending were applied to this model to calculate the instantaneous responses of the IVD. The calcification and sclerosis in the CEP were simulated with increase of its modulus and decrease of its per⁃ meability and porosity, compared with a healthy case. The results show that, the pore pressures within the CEP and the nucleus pulposus (NP) increase and the fluid velocity decrease in the degenerated CEP. Under flexion, the pore pressure in the NP increase by 50. 8% and 88. 9% in calcified and sclerotic CEPs compared to the healthy endplate, respectively. The decreases of the permeability and the water content in the degenerated CEP hinder the fluid flow and increase the maximum principal stresses of the NP matrix by 122.2% and 100.0% under compression and axial rotation, respectively.