使用有限元法模拟枕寰枢复合体的中性区

目的为枕颈部中性区（NZ）的研究建立有效的数学模型。方法本研究基于可视人数据库建立了枕寰枢复合体的非线性有限元模型,通过细致的轮廓提取和准确的材料特性定义,以提升上颈椎有限元模型的精确性。模型模拟了在静态生理载荷作用下复合体轴向旋转、前屈、后伸和侧弯运动。结果模型预测的运动范围（ROM）和NZ与实验数据相吻合。模型的力矩-转动关系呈明显的非线性关系,最大旋转发生在水平面,其次是正中矢状面和冠状面,且轴向旋转与侧弯相互耦合。模型总体表现出较大的ROM和较高比例的NZ。结论现有文献中尚未见到能同时成功验证ROM和NZ的上颈椎有限元模型。此模型可为枕颈部病变与创伤中出现的异常NZ的研究提供有力的辅助。

Simulation of the Neutral Zone of C0-C1-C2 Complex by Finite Element Method

Objective To develop a valid mathematic model for the research of the neutral zone(NZ) in craniovertebral junction.Method An anatomic detailed,nonlinear finite element(FE) model of the occipito-atlanto-axial(C0-C1-C2) complex based on Visible Human Male dataset was developed in this study,which can improve the previous upper cervical spine FE models by its increased geometric modeling accuracy and more precise material assignment.The model simulated the movements of upper cervical spine under axial rotation,flexion,extension,and lateral bending under physiological static loadings.Result The range of motion(ROM) and NZ agreed well with published experimental data.The moment-rotation relationship predicted by this model was apparently nonlinear,and the largest rotation was predicted in horizontal plane,followed by median plane and coronal plane. Axial rotations and lateral bending were strongly coupled with each other.The complex exhibited large ROM and high proportions of NZ to ROM.Conclusion There are no published results of FE models of upper cervical spine by far that have already undergone validations for both ROM and NZ.Therefore,it can be concluded that the current FE model validated for NZ is useful in the investigation of abnormal NZ in disease and trauma of craniovertebral junction.