颈椎前路椎管扩大的三维有限元研究

Three-dimensional finite elements study of anterior enlargement of cervical spinal canal

目的:运用三维有限元法分析颈椎前路椎体撑开的安全性和椎管扩大的有效性。方法:采用下颈椎(C5)三维有限元模型,模拟颈椎前路椎体开槽撑开过程,分别施加80、120、160 N荷载,采用静态分析方法对模型进行线弹性分析,观察应力分布与应变特征,并重建颈椎应变的截面轮廓图进行比较分析。结果:C5有效应力主要集中在椎板近棘突处,椎板内外壁主应力方向不同。应变后椎管面积增加率最大,集中在椎管中央和侧方;壁椎管内壁径增加率最小,160 N载荷下椎管内壁的变形率为1.77％。结论:颈椎前路椎体撑开可扩大椎管,有效减小椎管内压应力,并提示在一分限度内是安全的。

Objective:To evaluate the safety and effect of anterior enlargement of cervical spinal canal by slotting and unfurling the vertebral body using the finite element approach. Methods: The stress distribution and strain on the cervical spinal vertebra was analyzed using the three-dimensional finite elements model of Cs vertebra,simulated anterior enlargement of cervical spinal canal by slotting and unfurling the vertebral body under various transverse static load in a linear elasticity procedures, load forces were 80,120,160 N respectively. The changes of spinal canal was analyzed by reconstructing the figure of cervical spinal canal with AUTO CAD software. Results : The von Mises stresses mostly distributed at the lamina of vertebral arch nearby spinal process. The principal stresses on the external lamina of vertebral arch showed compressive stress,and tensile stresses were found at the internal lamina of vertebral arch. The increase rate of the internal lamina inline length was 1. 77% while the loading force reached 160 N. Conclusion: The present study suggests that slotting and unfurling the vertebral body by anterior approach can enlarge cervical spinal,relieving the internal pressure of spinal canal effectively and safely.