人与成年猕猴全颈椎有限元模型建立及有效性验证的对比

Comparison of finite element model establishment and validity verification of total cervical vertebrae between human and adult rhesus monkeys

背景:猕猴颈椎与人类颈椎具有高度相似性,无论颈椎数量还是椎骨解剖结构,尤其是均具有颈椎所特有结构——钩椎关节,因此可以作为理想的动物实验模型,但关于二者间的力学对比研究则鲜有报道。目的:建立成人颈椎与成年猕猴颈椎的有限元模型,围绕钩椎关节的受力特点利用有限元分析手段比较二者间在6种工况下的应力与位移变化特点,为临床椎体置换等提供理论依据。方法:选取1例40岁成人志愿者和1只7岁龄的成年雄性猕猴,分别进行螺旋CT薄层扫描,将原始颈椎CT数据导入Mimics 21.0中初步建立三维模型,通过颈椎各节段、椎间盘、韧带等模型优化、赋值、装配组织网格,最后利用Abaqus构建颈椎有限元模型,分别对模型加载75 N附加载荷和1 N·m外力偶矩,在前屈、后伸、左右侧屈和左右旋转6种工况下进行力学对比分析,以发现二者间的力学变化趋势和差异。结果与结论:①人和猕猴颈椎均具备颈椎特有的结构——钩椎关节,通过有限元建模比较发现二者间钩椎关节应力变化和位移变化走势基本一致,应力和位移集中点均在C5处,人和猕猴间比较差异有显著性意义;②但猕猴仍可作为临床颈椎动物模型的最佳备选动物,为临床人工颈椎椎体置换等方面提供理论依据。

BACKGROUND:There is a high similarity of the cervical vertebrae between rhesus monkeys and human,both in terms of the number of cervical vertebrae and the anatomical structure of cervical vertebrae,especially the uncinate joints,which are unique to the cervical vertebrae,so they can be used as an ideal animal experimental model.However,there are few reports on the mechanical comparative study between the two.OBJECTIVE:To establish the finite element model of adult human cervical vertebra and adult rhesus monkey cervical vertebra,to compare the characteristics of stress and displacement of the uncinate joint between human and rhesus monkey cervical vertebra under six working conditions by means of finite element analysis,and to provide theoretical basis for clinical vertebral replacement.METHODS:A 40-year-old adult volunteer and a 7-year-old adult male rhesus monkey were scanned by spiral CT.The original cervical vertebra CT data were introduced into Mimics 21.0 to establish a preliminary three-dimensional model.Through the optimization,assignment,assembly and other tissue grids of each segment of cervical vertebra,intervertebral disc,ligament and so on,the cervical vertebra finite element model was constructed by Abaqus,and 75 N additional load and 1 N·m external force couple moment were loaded on the model.Comparative mechanical analysis was carried out under six working conditions of flexion,extension,lateral area and rotation,in order to find the mechanical change trend and difference between them.RESULTS AND CONCLUSION:(1)Both human and rhesus monkey cervical vertebrae had the unique structure of uncinate joint of cervical vertebrae.Through finite element modeling,the stress and displacement changes of the uncinate joint between them were basically consistent,and the stress and displacement concentration points were all at C5.There was a significant difference between them.(2)However,the cervical vertebra of rhesus monkey can be used as the best candidate animal for clinical cervical vertebra animal model,and provide theoretical basis for artificial cervical vertebra replacement.