颈椎单侧半椎板及不同程度小关节切除术后生物力学变化的有限元分析  

Biomechanical changes of cervical spine after unilateral hemilaminectomy and different degrees of facetectomy:a finite element analysis

作　　者：吴超[1] 王振宇[1] 林国中[1] 于涛[1] 荣起国[2] WU Chao;WANG Zhenyu;LIN Guozhong;YU Tao;RONG Qiguo(Department of Neurosurgery,Peking University Third Hospital,Beijing 100191;Department of Biomedical Engineering,College of Engineering,Peking University,Beijing 100871,China)

机构地区：[1]北京大学第三医院神经外科,北京100191 [2]北京大学工学院生物医学工程系,北京100871

出　　处：《中华神经外科疾病研究杂志》2018年第4期352-356,共5页Chinese Journal of Neurosurgical Disease Research

基　　金：国家自然科学基金资助项目(81441044)

摘　　要：目的在人体颈椎有限元模型上观察单侧半椎板及不同程度同侧小关节切除术后颈椎生物力学的改变。方法构建人体正常颈椎C2-T1节段的三维有限元模型,并在此模型的上模拟C4-6半椎板切除及不同程度(25%,50%,75%)同侧C4-5小关节切除术。将T1椎体下端固定作为边界条件,采用3种加载模式于C2椎体上表面施加1.5 N·m的加载并使其产生前屈、后伸、侧屈和旋转运动。计算得到并比较不同手术模型的椎体节段间活动度及相应状态下韧带的拉力变化,小关节、终板和椎间盘的压力变化。结果在屈伸、侧弯和旋转状态下各手术模型节段间活动度的变化主要在C4-5节段,活动度随着小关节切除范围的增加而增加,在小关节切除范围大于50%时增加显著;三种运动状态下终板、纤维环和左侧小关节最大应力以及左侧关节囊韧带最大拉力的变化主要发生在C4-5节段,最大应力和最大拉力的增加随着小关节切除范围的增加而增加,在切除范围大于50%时增加显著。结论单侧半椎板切除时,如同时伴小关节切除,术后即刻会降低小关节切除节段的稳定性,切除超过50%时降低显著。单侧半椎板切除合并小关节切除术后会增加小关节切除节段的手术侧关节囊韧带拉力,小关节应力、椎间盘纤维环和终板的应力,破坏超过50%时增加明显。Objective The biomechanical effects of unilateral hemilaminectomy and different degrees of facetectomy in the cervical spine finite element model of the human body were studied. Methods A threedimensional finite element model of the cervical spine with C2-1 segment was established. C4-6 hemilaminectomy and ipsilateral C4-5 facetectomy with different degrees（ 25%,50% and 75%） were simulated on the basis of this model.The lower end of the T1 vertebra was constrained in all directions as boundary conditions,and then pure moment of1. 5 N·m was applied over the top surface of C2 vertebra to simulate the movement of cervical spine along the sagittal,coronal,axial direction. The intersegmental motion（ ISM）,tension and stress were calculated. Results Changes of ISM under flexion-extension,lateral bending and axial rotation station were mainly in C4-5 segment,the ISM increased with the increase of the range of facetectomy and increased significantly when the excision was over50%. Changes of the maximum stress in annulus,endplates,left facet joints and left capsular ligaments under flexion-extension,lateral bending and axial rotation station were mainly in C4-5 level. The maximum stress increased with the increase of the range of facetectomy and increased significantly when the excision was over 50%. Conclusion It can reduce the immediate cervical instability when ipsilateral facetectomy after hemilaminectomy. The reduction is significant when the excision is over 50%. Unilateral hemilaminectomy combined with facetectomy can increase the tension of capsular ligament and the stress of facet joint,annulus and endplate at the facetectomy segement and the this increase is significant when the excision is over 50%.

关 键 词：颈椎 半椎板切除 小关节切除生物力学 有限元 

分 类 号：R687.3[医药卫生—骨科学]