Abstract:

BACKGROUND: Fluid related biomechanical behavior of intervertebral disc is difficult to acquire from traditional research on spinal biomechanics. A few porous elastic finite element models are applied to investigate the behavior of lumbar two-phase at abroad. However, there are rarely related reports in China.
OBJECTIVE: To establish the fluid-solid coupling finite element model of the lumbar motion segment by the ANSYS12.1 software and to promote the wide application of finite element method in the spinal biomechanics.
METHODS: Spiral CT scan was performed in the L4-5 motion segment of a male volunteer without any spinal disease. The CT data was imported to the software of Mimics10.01 to create the geometric model of the L4-5 motion segment which was re-constructed to the 3D NURBS surface with the software of Gomagic9.0. The solid model was established using ANSYS12.1 software, and the model included cortical bone, cancellous bone, cartilaginous endplates, nucleus pulposus, and annulus matrix. A three-dimensional fluid-solid coupling finite element model of the L4-5 motion segment was established after a series of processes such as assigning parameters, meshing models, boundary setting, loading and solution. The height change of intervertebral disc of the model was compared with the vivo results to verify the validity of the model.
RESULTS AND CONCLUSION: The established fluid-solid coupling finite element models of L4-5 motion segment has 210 718 nodes and 85 973 elements. The height change of the intervertebral disc was consistent with that of the in vivo results. The fluid-solid coupling finite element model of porous media has accurately simulated biomechanical features of human lumbar spine.