摘要
目的 通过有限元分析比较双头螺钉与传统连接器多棒结构在脊柱后路三柱截骨术后矫形固定的稳定特性。方法 基于重度脊柱角状后凸患者术后CT数据建立T3~L4胸腰椎有限元模型。在患者标准双棒模型(2R)基础上,分别建立双头螺钉多棒结构模型(double-head screws, 4R-DHS)和传统连接器多棒结构模型(traditional connectors, 4R-TC)。在300 N随动载荷和7.5 N·m力矩载荷下对模型进行评估,分析两种多棒结构的稳定性、主棒上最大von Mises应力及应力分布。结果 两种多棒结构的稳定性差异不大。相比于4R-TC,4R-DHS除了后伸时主棒上最大von Mises应力略有增加外,其余运动中主棒上最大von Mises应力均有所下降(屈曲、左侧弯、左侧弯、右侧弯、左轴向旋转、右轴向旋转应力分别下降7.2%、8.8%、8.7%、18.5%、16.9%),并且应力分布更加均匀。结论 双头螺钉多棒结构相比于传统连接器多棒结构可以降低主棒上的最大应力,且不存在连接器附近主棒应力集中的问题,可以更有效降低内固定失效风险。
Objective To compare the stability of multi-rod structures with double-headed screws and traditional connectors in posterior three-column osteotomy of the spine using finite element analysis.Methods A finite element model of the T3-L4 thoracolumbar spine was constructed based on postoperative computed tomography(CT)data of patients with severe kyphosis.Based on the patient’s standard two-rod model(2R),a double-headed screw multi-rod structure model(4R-DHS)and a traditional connector multi-rod structure model(4R-TC)were constructed.The two models were evaluated under 300 N follower load and 7.5 N·m moment load,and the stability,maximum von Mises stresses on the main rods,and stress distributions of the two multi-rod structures were analyzed.Results There was little difference in the stability between the two multi-rod structures.Compared with 4R-TC,4R-DHS showed a decrease in the maximum von Mises stresses on the main rods during all motions(the stress decreased by 7.2%,8.8%,8.7%,18.5%,and 16.9%during flexion,left lateral bending,right lateral bending,left axial rotation,and right axial rotation,respectively)and more uniform stress distribution,except for a slight increase in the maximum von Mises stresses on the main rods during post-extension.Conclusions The double-headed screw multi-rod structure can reduce the maximum stress on the main rod compared with the traditional connector multi-rod structure,and there is no problem with stress concentration on the main rod near the connector,which can more effectively reduce the risk of internal fixation failure.
作者
廖运钱
周宇
王政伦
刘永胜
李炜
LIAO Yunqian;ZHOU Yu;WANG Zhengun;LIU Yongsheng;LI Wei(Tribology Research Institute,Southwest Jiaotong University,Chengdu 610031,China;State Key Laboratory of Vanadium and Titanium Resources Comprehensive Utilization,Panzhihua 617000,Sichuan,China;Chengdu Advanced Metal Materials Industry Technology Research Institute Co.,Ltd.,Chengdu 610300,China)
出处
《医用生物力学》
CAS
CSCD
北大核心
2024年第3期407-412,共6页
Journal of Medical Biomechanics
关键词
三柱截骨术
双头螺钉
连接器
有限元分析
three-column osteotomy
double-headed screw
connector
finite element analysis
