融合与Topping-off术对腰椎影响的有限元分析  

Finite element analysis of lumbar fusion and Topping-off surgery

作　　者：刘海鹰[1] 王捷夫[1] 朱震奇[1] 

机构地区：[1]北京大学人民医院脊柱外科,北京100044

出　　处：《北京大学学报（医学版）》2013年第5期723-727,共5页Journal of Peking University:Health Sciences

基　　金：北京市科学技术委员会(骨科常见疾病诊疗规范及康复技术研究;D101100049910006)资助~~

摘　　要：目的：应用有限元方法分析Topping-off术对融合节段的相邻节段的影响.方法：建立L1~L5正常腰椎有限元模型,经与文献结果对比验证有效性后分别建立2种手术模型：（1）L4/L5节段融合的后路腰椎椎间融合术（posterior lumbar intervertebral fusion,PLIF）模型,（2）L4/L5节段融合及L3/L4节段植入棘突间固定装置（interspinous spacer,ISP）的Topping-off模型.分别对两者L1椎体上终板施加500 N垂直压缩载荷以及10 Nm前屈、后伸、（左）侧屈和（右）旋转力矩载荷,观察L3/L4节段活动度、椎间盘压力、小关节应力及L3、L4棘突应力情况,使用SPSS 21.0统计软件对结果进行分析.结果：在前屈、后伸载荷下,Topping-off模型L3椎体相对位移、椎间盘纤维环及髓核压力、双侧小关节应力小于PLIF模型（P〈0.05）,L3、L4椎体棘突应力大于PLIF模型（P〈0.05）.在左侧屈载荷下,Topping-off模型L3/L4节段左侧小关节应力小于PLIF模型（P〈0.05）.结论：Topping-off术能够降低融合相邻节段的椎间盘和小关节负荷,具有潜在的预防融合相邻节段退变的作用.Objective：To evaluate the effect of Topping-off surgery on the adjacent segment of PLIF. Methods： A finite element model of the human lumbar spine （ L1 - L5 ） was developed. The intact spi- nal model was validated by comparing it with previously reported models. Then, 2 models were analyzed and compared： （ 1 ） posterior lumbar interbody fusion （PLIF） at IA/5 ; （2） posterior lumbar interbody fusion at IA/5 and implantation of the interspinous spacer （ISP） at L3/4 （Topping-off）. Then 500 N compressive loading plus 10 Nm moments simulating flexion, extension, lateral bending and axial rotation were imposed on both the L1 superior endplates. The ranges of motion, intradiscal pressures, facet stres- ses in L3/4, the stresses on spinous processes in L3 and IA were investigated. All the measured data were analyzed by SPSS 21.0. Results： The effect of the Topping-off on the adjacent segment appeared mainly in flexion-extension ： the ranges of motion, intradiscal pressures （ annulus and nucleus pulposus）, both facet stresses were lower than that of the PLIF model, and the stresses on spinous processes in L3 and L4 were larger. Besides, the facet stresses on the left side in the left lateral bending were also lower than those of the PLIF model. Condusion： Topping-off model is able to restrict the range of motion of the lumbar adjacent segment, decrease the intradiscal pressure and facet stresses, and has a potential effect of oreventin~ adiacent segmental degeneration.

关 键 词：脊柱融合术 腰椎 生物力学 有限元分析 Topping—off术 

分 类 号：R681.5[医药卫生—骨科学]