骶骨螺钉四种固定方式生物力学特性的有限元分析  

Finite Element Analysis of Biomechanical Property of Four Fixation Techniques of Sacral Screw

作　　者：郑良孝[1] 聂林[1] 

机构地区：[1]山东大学齐鲁医院骨创科,济南市250012

出　　处：《中国骨与关节损伤杂志》2008年第4期302-305,共4页Chinese Journal of Bone and Joint Injury

摘　　要：目的研究骶骨螺钉四种不同固定技术的生物力学性能并进行有限元分析。方法取6具完整10%甲醛液浸泡固定的湿润成人脊柱标本(L5S1),两侧分别采用螺钉经椎弓根椎体间内固定(PTSF)法、前内骶岬法和经前内单、双边皮质固定四种骶骨固定技术。通过模拟生理应力进行疲劳试验,测定固定刚度变化和抗拔出力。根据骶骨的CT片采用计算机辅助技术建立骶骨的三维有限元模型。结果PTSF法固定组螺钉最大扭矩为(3.32±0.63)Nm,且抗拔出力最大,最大可达(1623±327)N。在循环负载过程中,PTSF法固定组的最后刚度高于其他三组(P<0.05)。四组中螺钉的最大扭矩与抗拔出力均有显著相关性。试件的结构刚度、剪切模量及骨小梁组织的弹性模量等材料性质越高,骶骨螺钉抗拔出力越大。结论PTSF法骶骨螺钉的旋入扭矩和抗拔出力最大,固定最坚强,前内骶岬法次之,经前内单侧皮质固定组最差。Objective To analyze finite element of biomeehanieal property of four different fixation techniques of sacral screw. Methods Six cases of adult cadaver specimens （L5S1） which was soaked and fixed in 10% formalin liquid were used in this study. Four fixation techniques of sacral screw were used including PTSF method, anteromedial sacropromontory method and anteromedial unilateral or bilateral sacral screws method. The stiffness was monitored during cyclic loading and the pullout tests were conducted after the completion of the fatigue tests. Based on the CT pictures, the three - dimensional geometrical model of sacrum was derived through auto CAD technology. The mechanic parameters obtained from the literature were applied to the model, and the three-dimensional finite element model of intact sacrum was constructed. Results The maximam torque and average anti-pull-out force following cyclic loading were the significantly highest in the fixation of PTSF method, mean （3.32±0.63） Nm and （1623±327） N respectively. During the process of cyclic loading, the final stiffness of fixation of PTSF method was higher than the other three metheds （P〈0.05）. The four fixation techniques of sacral screw showed high correlations between insertion torque and pullout strength following cyclic loading. The higher the material properties, such as stiffness, shear modulus and Young＇ s modulus of trabecular tissue were, the stronger the ratio of anti- pull-out was. Conclusion PTSF fixation techniques of sacral screw is the most rigid way of sacral fixation, anteromedial sacropromon-tory method is the second, and anteromedial unicortical sacral screws method is the worst.

关 键 词：骶骨螺钉 固定方式 生物力学 有限元分析 

分 类 号：R323.43[医药卫生—人体解剖和组织胚胎学] R783.6[医药卫生—基础医学]