钢板内固定系统重建椎管的生物力学分析  

Biomechanical analysis of miniplate fixation systems in restorative laminoplasty for spinal canal reconstruction

作　　者：陈建民 刘国印 包天翼 柏天婷 张二来 赵建宁 CHEN Jianmin;LIU Guoyin;BAO Tianyi;BAI Tianting;ZHANG Erlai;ZHAO Jianning(Department of Orthopedics,Jinling Hospital of Nanjing Medical University,Nanjing 210002,China;Xiamen Medical Device Testing and Research Co.,Ltd,Xiamen 361022,China)

机构地区：[1]南京医科大学金陵临床医学院骨科,江苏南京210002 [2]厦门医疗器械研发检测中心有限公司,福建厦门361027

出　　处：《南方医科大学学报》2023年第3期331-339,共9页Journal of Southern Medical University

基　　金：国家自然科学基金青年科学基金(82102547);南京军区重点项目(15ZD020)。

摘　　要：目的比较椎板切除回植后应用不同钢板内固定系统(微H钢板和微L钢板)重建椎管的生物力学性能。方法应用3D打印技术打造正常腰4(L4)椎体模型,对L4椎体模型实施全椎板切除,根据椎板回植椎管重建(RL-SCR)内固定方式的不同分成微H钢板(H-MFS)组和微L钢板(L-MFS)组;分别通过静态压缩和动态疲劳压缩实验对两组RL-SCR模型进行加载直至钢板失效、断裂或回植椎板塌陷;静态压缩实验采用速度控制模式,动态疲劳压缩实验采用载荷控制模式。同时,通过建立正常L3-L5有限元模型,在验证该模型有效性的前提下进行RL-SCR的生物力学研究;根据处理方式不同分为正常赋值组、椎板切除组、H-MFS组和L-MFS组;在相同载荷下,模拟前屈、后伸、左弯、右弯、左旋和右旋6个方向的生理活动条件,对各组L3-L4和L4-L5的活动度(ROM)变化进行评估。结果RL-SCR静态压缩实验中,H-MFS组的持续屈服载荷大于L-MFS组(P<0.05),在相同机械载荷下的压缩刚度、屈服位移和轴向位移-轴向载荷排列为:H-MFS组>L-MFS组(P<0.05);L-MFS组全部出现椎板原位还纳或“闭门”现象及椎板塌陷,均出现钢板断裂现象;而H-MFS组未出现钢板断裂现象,仅部分出现螺钉周围的钢板裂纹和螺钉尾帽松动的现象;RL-SCR的动态压缩疲劳实验中,H-MFS组的动态压缩峰值载荷可达873 N,为静压缩平均屈服载荷的95%,优于L-MFS组(P<0.05);而L-MFS组的动态压缩峰值荷载仅为468 N,为静压缩平均屈服载荷的80%;此外,根据疲劳寿命-峰值载荷图估算出L-MFS组的极限载荷仅为H-MFS组的46.59%,差异有统计学意义(P<0.05)。与椎板切除组相比,6种加载工况下,正常赋值组、H-MFS组和L-MFS组L3-L4和L4-L5的ROM范围均明显降低;与正常赋值组相比,H-MFS组仅在后伸时的ROM增加明显,而L-MFS组在前屈、后伸、左旋和右旋时的ROM增加明显;病变节段ROM的整体趋势为椎板切除组>L-MFS组>H-MFS组>正Objective To investigate the biomechanical properties of H-shaped and L-shaped miniplate fixation systems(H-MFS and L-MFS,respectively)in restorative laminoplasty for spinal canal reconstruction(RL-SCR).Methods Laminectomy was performed in a 3D printed L4 vertebral model followed by RL-SCR using H-MFS or L-MFS,and the biomechanical properties of the reconstructed models were evaluated using static and dynamic compression tests.Biomechanical analyses of RL-SCR were also conducted in finite element models of the L3-L5 vertebrae with normal assignment(NA),laminectomy,or fixation with H-MFS or L-MFS,and the range of motion(ROM)of L3-L4 and L4-L5 was evaluated.Results In static compression test,the sustained yield load,compression stiffness,yield displacement and axial displacement-axial load were all significantly greater in H-MFS group(P<0.05).Door closing,lamina collapse and plate breakage occurred in all the models in L-MFS group,and only some models in H-MFS group showed plate cracks and screw loosening.In dynamic compression tests,the peak load in H-MFS group reached 873 N(which was 95%of the average yield load in static compression),significantly greater than that in L-MFS group(P<0.05).The ultimate load in L-MFS group was only 46.59%of that in H-MFS group(P>0.05).In finite element analysis,the ROM of the L3-L4 and L4-L5 segments were significantly smaller in NA,H-MFS and L-MFS groups than in laminectomy group.Compared with NA group,H-MFS group showed a greater ROM during extension,and L-MFS group showed greater ROM in flexion,extension,bending,and rotation;The overall ROM of the vertebral segments decreased in the order of laminectomy group,L-MFS group,H-MFS group,and NA group.Conclusion Laminectomy causes structural destruction of the posterior column of the spine to affect its biomechanical stability.RL-SCR can effectively maintain the biomechanical stability of the spine,and H-MFS is superior to L-MFS in maintaining the integrity and biomechanical properties of the reconstructed spinal canal.

关 键 词：椎板回植椎管重建 椎板钢板 3D打印 静态压缩 动态压缩 生物力学 有限元分析 

分 类 号：R687.3[医药卫生—骨科学] R318.01[医药卫生—外科学]