椎体后凸成形后相邻椎体生物力学的有限元分析  

Biomechanical finite element analysis of adjacent vertebral bodies following percutaneous kyphoplasty

作　　者：韩紫音[1] 路青林[1] 张敬涛[2] 张文强[1] 

机构地区：[1]山东大学附属千佛山医院骨科,山东省济南市250014 [2]山东大学生物医学工程研究所,山东省济南市250061

出　　处：《中国组织工程研究与临床康复》2010年第4期598-602,共5页Journal of Clinical Rehabilitative Tissue Engineering Research

摘　　要：背景:椎体后凸成形后相邻椎体新发骨折的发生率为2.4%～23%,并且6个月内2/3骨折发生于邻近椎体,其原因是骨质疏松的发展,还是骨水泥强化的结果,目前存有争论。目的:应用脊柱有限元分析方法分析生理载荷作用下,椎体后凸成形后相邻椎体终板的应力变化与相邻椎体新发骨折的相关性。方法:收集老年骨质疏松女性胸腰椎CT扫描资料,利用一系列计算机辅助设计软件构造相对应的T12-L1-L2骨质疏松性椎体的三维有限元模型。模拟L1椎体为楔形压缩骨折椎体(前缘高度较正常降低60%),模拟经皮椎体后凸成形模型,复位骨折椎体(L1椎体高度较正常降低10%,代表骨折椎体复位),在L1椎体内置入2个对称的圆柱体PMMA骨水泥块共约4mL。分析轴向压缩、前屈和后伸3种加载状态下正常椎体、手术前后相邻椎体的应力变化情况。结果与结论:与正常椎体比较,L1压缩性骨折模型和椎体后凸成形后模型相邻椎体终板最大应力值分别增高76%和27%;椎体后凸成形模型后部结构的应力水平较正常椎体平均增加13.2%,其中椎弓根增加4.5%,峡部增加6.15%和关节点增加25.6%。与L1椎体压缩性骨折模型相比,L1椎体后凸成形后椎弓根、峡部和关节突应力均有所降低。结果说明椎体后凸成形后,T12椎体下位终板和L2椎体上位终板的应力值在各种状态下均较正常椎体增加,应力增加可能导致终板骨折可能性增加,进而导致相邻椎体骨折的风险性增加,这一观点尚需进一步研究的支持。BACKGROUND： The incidence of the adjacent vertebral fracture after kyphoplasty is about 2.4%-23.0%, and 2/3 of new fractures occurred in adjacent vertebrae in 6 months. There is controversy addressing the reason which is the development of osteoporosis or the result of bone cement augment at present. OBJECTIVE： To determine the correlations between percutaneous kyphoplasty on adjacent vertebral endoplates stresses pressure under physiologianl load and a new fracture of adjacent vertebral body in physiological load. METHODS： Computed tomography （CT） data of an old female osteoporotic patient was selected, and a three-dimensional finite element model of the osteoporotic thoracolumbar spine T12-L1-L2 was created by using kinds of computer aided design software. The height of vertebral L1 was compressed by 60% to simulated the compressed fracture, and the height of L1 became the 90% of normal to simulate the replacement, two columns-like PAMA mass （4 mL） was placed in vertebral L1 to simulate percutaneous kyphoplasty. The stress on inferior endplate of T12 and superior endplate of L2 was compared with three models. RESULTS AND CONCLUSION： Compared to the normal vertebral body, the maximum stress in the adiacent vertebral bodies endplates increased by 76% for L1 compress fracture model and increased by 27% for kyphoplasty model, respectively. The stress on the posterior part of vertebral body after percutaneous kyphoplasty have an average increase of 13.2%, of which 4.5% increase in the pedicle, isthmus, and 6.15 % increased in the key points 25.6%, but with the wedge-shaped fracture of L1 vertebral body compared to the model, percutaneous kyphoplasty after pedicle, isthmus and the articular process had reduced stress. The results indicate that the stress on inferior endplate of T12 and superior endplate of L1 increased after percutaneous kyphoplasty under all loading conditions. Increased stress may lead endplate fracture, and increase the risk of adjacent vertebral body fracture. Further researches a

关 键 词：经皮穿刺椎体后凸成形 有限元分析 骨质疏松性椎体压缩性骨折 应力 生物力学 

分 类 号：R318[医药卫生—生物医学工程]