以有限元法比较前路腰椎间融合后路关节突关节螺钉/椎弓根螺钉的固定应力  

Stress of facet screw/pedicle screw fixation after anterior lumbar interbody fusion with finite element model

作　　者：敖俊[1] 方国芳[2] 靳安民[2] 张辉[2] 闵少雄[2] 于博[2] 

机构地区：[1]遵义医学院附属医院骨科,贵州省遵义市563003 [2]南方医科大学珠江医院骨科,广东省广州市510282

出　　处：《中国组织工程研究与临床康复》2009年第35期6855-6860,共6页Journal of Clinical Rehabilitative Tissue Engineering Research

基　　金：遵义医学院硕士科研启动基金资助项目~~

摘　　要：背景：对腰椎前路腰椎间融合后辅助固定的各种关节突关节螺钉的生物力学安全性存在普遍担忧,限制其临床应用,未见文献报道与椎弓根螺钉固定的比较研究。目的：建立L4-5椎前路椎间融合后路分别用双侧椎弓根螺钉、经椎板关节突螺钉及经关节突椎弓根螺钉固定的三维有限元模型,施加相同的负荷和转矩,比较分析3种螺钉和椎间融合器的应力状况。设计、时间及地点：对比观察,于2008-02/2009-01在南方医科大学珠江医院骨科实验室完成。材料：PHILIPS Brilliance64排螺旋CT扫描仪,数据输出DICOM 3.0格式;Mimics 11.1软件;Simpleware 3.1软件;Abaqus 6.8软件;Photoshop 7.0软件;DEPUYAcroMed皮质骨螺钉和Zimmer椎间融合器;GSS椎弓根螺钉系统。方法：建立L4-5椎前路椎间融合后路分别用双侧椎弓根螺钉、经椎板关节突螺钉及经关节突椎弓根螺钉固定的三维有限元模型。对3种螺钉固定的有限元模型施加500N/6N·m载荷模拟前曲、后伸、左侧弯、左旋运动,用Abaqus 6.8软件比较分析3种螺钉和椎间融合器的应力变化和分布特点。主要观察指标：应力峰值,应力集中区云图。结果：在500N/6N·m载荷下,椎弓根螺钉在屈、伸时的应力较两种关节突关节螺钉固定应力小,在侧弯和轴向旋转时较大;两种关节突关节螺钉应力特点相似。在椎弓根螺钉坚强固定时,椎间融合器有应力遮挡现象。结论：在较小的转矩下,前路腰椎间融合后两种关节突关节螺钉固定的安全性和椎弓根螺钉固定相近。使用关节突关节螺钉固定,除减少创伤、节约成本等优点外,还可减少对椎间融合器的应力遮挡效应。BACKGROUND： No reports have been found about stress comparative study between facet screw and pedicle screw fixation after anterior lumbar interbody fusion （ALIF）, which limits clinical application of facet screw due to their uncertain biomechanical safety. OBJECTIVE： To develop a 3D finite element model of the different facet screws fixation and pedicle screws fixation in L4-5 motion segment and to evaluate the stress feature of three kinds of screws and cages in ALIF under the same loading. DESIGN, TIME AND SETTING： Comparative observation was performed at the laboratory of Department of Orthopedics, Zhujiang Hospital of Southern Medical University from February 2008 to January 2009. MATERIALS： PHILIPS Brilliance 64-slice spiral CT scanner （DICOM 3.0 format）; Mimics 11.1 software; Simpleware3.1 software; Abaqus6.8 software; Photoshop 7.0 software; DEPUY AcroMed cortical screw and Zimmer lumbar cage; GSS pedicle screw system. METHODS： 3D finite element model of bilateral pedicle screws, translaminar facet joint fixation and transarticular pedicle screw fixation following ALIF was established. 500 N/6 N·m load was used on the upper surface of L4 of ALIF supplemented with three types of screws to simulate lumbar flexion, extension, left lateral bending and left axial rotation. Stress changes and distribution of the three kinds of screws fixation and cages were compared and analyzed using Abaqus 6.8 software. MAIN OUTCOME MEASURES： Peak stress and stress distribution. RESULTS： The stress of pedicle screws in extension/flexion were less than the stress of facet screws, but the stress of pedicle screws in bending/axial rotation were greater than the stress of facet screws under 500 N/6 N·m loading. The stress features were similar between two types of facet screws. There was stress-shielding at interbody cages because of pedicle screw robust fixation. CONCLUSION： Under the same loading, the safety of facet screw fixation after ALIF was similar to pedicle screw fixation. It may relieve stress

关 键 词：腰椎 脊柱融合术 关节突固定 椎弓根螺钉 三维有限元 

分 类 号：R318[医药卫生—生物医学工程]