腰椎侧凸螺钉内固定节段对手术矫正效果影响的有限元分析

The effect of instrument segments on the correction rate of lumbar scoliosis，a finite element analysis

中文关键词:  脊柱侧凸  生物力学  有限元分析

英文关键词:Spine scoliosis  Biomechanics  Finite element analysis.

中文摘要:

  【摘要】　目的：应用有限元分析的方法，模拟腰椎侧凸矫形手术，探讨内固定螺钉位置对脊柱侧凸矫形的效果。方法：利用Simpleware软件建立L1～L5侧凸的三维有限元模型，侧凸角40°。在此模型上设计6组（A～F组）凹侧椎弓根螺钉置入计划，其中A-E 组为5个椎体依次空缺1个螺钉，F组作为对照行5个椎体置钉，连接矫形棒。应用ANSYS和ADAMS软件，计算矫形过程中反旋转和回弹时置入物所受载荷（最大扭矩及最大拔出力）以及脊椎的应力应变场。结果：6组矫形结束后的侧凸角分别为30°、23°、25°、22°、29°、21°。所需最大扭矩分别为3.1N·m、3.3N·m、4.6N·m、3.4N·m、4.2N·m和3.3N·m。螺钉所承受最大拔出力分别为418N、383N、437N、395N、420N和380N。结论：在保持一定固定范围条件下，间断减少非弧顶固定螺钉，在三维有限元模型上可得到较好的矫形效果。

英文摘要:

  【Abstract】 Objective：To simulate the correction surgery of lumbar scoliosis by finite element analysis and investigate the effect of instrument segments on the correction rate of lumbar scoliosis．Method：A detailed three-dimensional finite element scoliotic model of L1-L5 with a Cobb angle of 40°on sagittal plane was established by using Simpleware software．Six types（group A-Ｆ）of pedicle screw instrumentations on concave side were designed on the model（of these，uniscrew placement in each vertebral body of group A-E，while biscrew placement in each vertebral body of group F）．The spinal stress and strain field during with respect to anti-rotation and the rebound in the process of correction were meassured by using software ANSYS and ADAMS software．Result：The scoliostic angle after correction was 30°，23°，25°，22°，29°and ２１°respectively for group A to E．The maximum torque was 3.1N·m，3.3N·m，4.6N·m，3.4N·m，4.2N·m and 3.3N·m，the maximum pull out force was 418N，383N，437N，395N，420N and 380N.Conclusion：Under definite circumstances，decreasing non-arc vertebrae screws can yield good correction at least in finite element model.