人体腰椎模拟植入椎弓根螺钉的有限元分析

利用三维绘图软件构建人体腰椎L4-L5节段几何模型,并模拟植入椎弓根螺钉.通过UG与Ansys Workbench的无缝接口将所建模型导入后者,对模型赋值并进行有限元分析,得出在人体站立情况下腰椎的应力云图与位移云图.从云图中可看出正常腰椎模型的最大应力出现在L4下关节突附近,值为15.073 MPa;最大位移出现在椎间盘上表面前部,值为0.161 mm.植入椎弓根螺钉的腰椎模型最大应力出现在螺钉的中部,值为38.613 MPa;最大位移出现在第4腰椎上端的前部,值为0.136 mm.结果表明：植入的椎弓根螺钉可缓解椎体的承载负担,并且可使腰椎变形减小.该结论可为同类腰椎固定手术以及脊柱的生物力学分析提供理论参考.

Finite element analysis of the lumbar model of implanting pedicle screw fixation system

The geometry model of L4-L5 lumbar segment and the model of lumbar that implanted pedicle screw fixation system were constructed on three-dimensional graphics software. Then, the model was imported into ANSYS Workbench to be analyzed in the condition of human upright and resulted in the equivalent stress of normal human lumbar and the nephogram of displacement. It was showed that the maximum stress was 15.073Mpa which was on the L4 zygopophysis and the maximum displacement was 0.16hum which was located in upper surface of intervertebral disc in the model of normal lumbar segment; the maximum stress was 38.613Mpa which was located in the middle of screws and the maximum displacement was 0.136mm which was located in upper surface of L4 lumbar in another. The results showed that the pedicle screws could alleviate the vertebral bearing burden, and it could decrease the deformation of lumbar spine. The conclusion was to be the theoretical reference to analysis of the lumbar operated and spinal biomechanics as well.