腰骶椎带锁轴向融合内固定器的有限元分析  

Finite element analysis of locking axial lumbosacral interbody fusion cage

作　　者：易新[1] 宋西正[1] Yi Xin;Song Xi-zheng(First Hospital of Nanhua University,Hengyang 421001,Hunan Province,China)

机构地区：[1]南华大学附属第一医院,湖南省衡阳市421001

出　　处：《中国组织工程研究》2018年第31期4982-4986,共5页Chinese Journal of Tissue Engineering Research

摘　　要：背景:为提高椎间融合的腰骶椎稳定性及融合率,作者结合国人腰骶椎研制了一种腰骶椎经皮带锁轴向融合器。目的:建立有效的腰骶椎带锁轴向融合固定三维有限元模型,分析不同载荷下螺钉应力分布,为其提供需要改进的目标和评价指标。方法:利用逆向工程软件Mimics、Geomagic建立正常成人腰骶椎有限元模型,模拟手术过程将腰骶椎带锁轴向融合器装配到有效的腰骶椎模型中,对其进行网格模型划分,建立起装配有带锁轴向融合器的腰骶椎有限元网格模型,根据腰骶椎和内固定的材料属性,对模型进行赋值,导入Solid works 2011中得到最终有限元模型。对模型施加生理及极限载荷,进行前屈、后伸、侧弯、旋转载荷运动,在Hypermesh软件完成带锁轴向融合器内部应力分布,评价其生物力学性能。结果与结论:在垂直压缩+前屈+左旋工况极限载荷下,骶椎带锁轴向融合器所承受的压强最大,为1 500.08 MPa,应力集中点为带锁轴向内固定融合器植骨孔左右两侧;其次为垂直压缩+前屈+右旋极限载荷下,带锁轴向融合器所承受的最大压强为1 318.00 MPa,应力集中点为带锁轴向内固定融合器植骨孔左右两侧,植骨孔上下两侧压强较小。在生理载荷下,内固定器能够提供足够的强度,保证稳定性和提高植骨融合率;在垂直压缩+前屈+旋转工况极限载荷下,内固定器承受的最大应力超过螺钉屈服强度,应改进工艺及加强植骨孔薄弱环节,术后早期卧床、佩戴支具,避免过伸、过屈或扭转等高强度运动。BACKGROUND:In order to improve lumbosacral stability and fusion,we developed a locking axial lumbosacral fusion cage for Chinese lumbosacral vertebrae.OBJECTIVE:To establish an effective three-dimensional finite element model of axial lumbosacral interbody fusion with locking plate and to analyze the stress distribution of the screw under different loads,and to provide targets and evaluation indexes to be improved.METHODS:A normal adult lumbosacral vertebra finite element model was established by reverse engineering software Mimics and Geomagic.The locking axial lumbosacral fusion cage was assembled into the effective lumbosacral vertebra model by simulating the surgical procedure.The mesh model was divided into two groups.A finite element mesh model of lumbosacral vertebrae fitted with the locking axial fusion cage was established.According to the material properties of lumbosacral vertebrae and fusion cages,the model was assigned and imported into SolidWorks 2011 to obtain the final finite element model.Under physiological and ultimate loads,the model was subjected to flexion,extension,lateral bending and rotation motions.The stress distribution in the axial-direction cage with locking was completed by Hypermesh software to evaluate its biomechanical properties.RESULTS AND CONCLUSION:The maximal compressive force of the locking axial lumbosacral fusion cage under the vertical compression+flexion+left-handed condition was 1 500.08 MPa,and the stress concentration point was located at the left and right sides of the bone hole.Then,under the vertical compression+flexion+right-hand limit load,the maximum pressure to be absorbed by the fusion cage was 1 318.00 MPa,and the stress concentration point was at the left and right sides of the bone hole,and there was a lower pressure at the upper and lower sides of the bone hole.Physiological load holders provide adequate strength,stability and bone-graft fusion.Under vertical compression+flexion+rotation conditions,the maximum stress exceeds the yield strength of the scre

关 键 词：带锁轴向融合器 腰骶椎 有限元 应力 生物材料 内固定器 腰椎 有限元分析 组织工程 

分 类 号：R318[医药卫生—生物医学工程]