摘要
目的：利用有限元方法分析比较不同椎板减压范围对脊柱动态内固定BioFlex系统生物力学的影响。方法：利用Mimics 10.01三维重建软件建立正常L3～L5几何模型并利用ProE逆向工程软件建立BioFlex系统几何模型，按临床术式进行组装并导入ANSYS Workbench 14.0有限元分析软件进行前处理建立四种L3～L5三维有限元模型：完整状态L3～L5模型（INT组），L4-L5椎板减压＋1/2关节突切除＋Bioflex模型（MF-BF组），L4-L5椎板减压＋全关节突切除＋Bioflex模型（TF-BF组），L4-L5椎板减压＋髓核摘除＋Bioflex模型（D-BF组）；在各模型L3椎体的上表面以及上关节突的关节面轴向予1200N载荷和8Nm、8Nm、6Nm、4Nm力矩下模拟人体腰椎正常生理轴向载荷、前屈、后伸、侧弯和扭转，L5椎体的下表面及下关节突表面各节点六个方向自由度完全固定。测量各模型固定节段和邻近节段的活动度以及邻近节段的髓核间应力与关节突应力，并进行分析比较。结果：椎板减压并置入动态内固定Bioflex系统后，脊柱固定节段的活动度各减压组较INT组明显减小（P＜0.05），其中TF-BF组前屈活动度减小幅度最大达77.2%，MF-BF组后伸、侧弯、旋转活动度减小幅度最大分别达37.4%、67.2%、83.1%；邻近节段的活动度各减压组较INT组增大（P＜0.05），其中MF-BF组前屈活动度增大幅度最大达22.9%，TF-BF组后伸、侧弯活动度增大幅度最大分别达18.2%、32.1%，DF-BF组旋转活动度增大幅度最大达13.8%。不同状态下固定节段及邻近节段活动度MF-BF组、TF-BF组及D-BF组间波动幅度不大，两两比较差异无统计学意义（P＞0.05）。邻近节段关节突应力及髓核间应力各减压组较INT组明显增大（P＜0.05），其中TF-BF组关节突应力在后伸、旋转活动时增大幅度最大分别达81.6%、77.3%，DF-BF组关节突应力在侧弯活动时增大幅度最大达60.5%，DF-BF组髓核
Objectives： To investigate the effect of different type of laminectomy on the biomechanical characteristics of BioFlex system by using finite element method. Methods： The normal L3-L5 geometry model was established by three-dimensional reconstruction software Mimics 10.01 and the BioFlex system geometry model was established by reverse engineering software ProE, and were assembled according to surgery and imported into ANSYS Workbench 14.0 finite element analysis software to establish four different types of laminectomy in finite element models, which included Intact（INT）, L4-L5 laminectomy ＋ 1/2 facet joint removal ＋ Bioflex（MF-BF）, L4-L5 laminectomy ＋ total facet joint removal ＋ Bioflex（TF-BF）, L4-L5 laminectomy ＋ discectomy ＋ Bioflex（D-BF）. All models were loaded under 1200N to simulate different spinal motions（flexion, extension, lateral bending and rotation） with torque 8, 8, 6, and 4Nm, respectively. The range of motion（ROM） at fixed and adjacent segment, the annulus stress and facet contact force（FCF） at adjacent segment were measured and analyzed. Results： The ROM at fixed segment decreased dramatically after laminectomy and placing of BioFlex system compared with INT group（P〈0.05）, and the ROM of TF-BF group decreased up to 77.2% in flexion and the ROM of MF-BF group decreased up to 37.4%, 67.2%, 83.1% in extension, lateral bend, and rotation respectively; while the ROM at adjacent segment increased obviously compared with INT group（P〈0.05）, the ROM of MF-BF group increased up to 22.9% in flexion, and the ROM of TF-BF group increased up to 18.2%, 32.1% in extension, lateral bend respectively and the ROM of DF-BF group increased up to 13.8% in rotation. The change of ROM at fixed and adjacent segment were little under different type of laminectomy, there was no significant differences between groups of MF-BF, TF-BF and DF-BF（P〉0.05）. The annulus stress and FCF at adjacent segment dramatically increased after laminectomy and placing of BioFlex
出处
《中国脊柱脊髓杂志》
CAS
CSCD
北大核心
2014年第4期372-378,共7页
Chinese Journal of Spine and Spinal Cord
基金
国家自然基金重大项目(61190120 61190122 61190123)
