自行防旋转寰枢椎钉棒内固定系统的生物力学有限元分析

发布时间：2018-02-21 11:18

本文关键词：有限元分析应力物理内固定器组织工程骨科植入物数字化骨科上颈椎寰枢椎失稳寰枢椎脱位后路内固定钉棒系统自行防旋转生物力学国家自然科学基金　出处：《中国组织工程研究》2017年19期 　论文类型：期刊论文

【摘要】：背景:寰枢椎后路内固定是目前治疗寰枢椎失稳和或脱位的主要术式,但是常规后路钉棒内固定系统中的连接棒是圆柱形,为增强复位功能,连接棒预弯的曲度一般较大,在拧螺母固定时连接棒容易发生旋转,需要额外的辅助器械把持和固定连接棒的方向,但辅助器械存在手术术野遮挡,且当辅助器械把持不稳时可能造成脊髓的过度骚扰和意外损伤。自行防旋转寰枢椎钉棒系统是一种既保持了常规钉棒系统的优点,又具有自行防旋转的功能,但其生物力学性能与常规钉棒系统之间的差异需进一步研究。目的:通过建立寰枢椎后路钉棒内固定系统的三维有限元模型,评估新型自行防旋转寰枢椎后路钉棒内固定系统的生物力学特性。方法:应用有限元分析软件创建上颈椎后路钉棒内固定系统的有限元模型,分析得出钉棒内固定系统的应力分布云图。结果与结论:建立的有限元模型几何相似性好,其中常规及新型钉棒系统模型分别包含198 330个节点和964 747个单元,246 788个节点和996 069个单元。两种内固定系统均无明显应力集中现象,且主要应力分布区域基本一致,主要集中螺钉-骨质界面、螺钉-连接棒界面,其中新型自行防旋转寰枢椎后路钉棒内固定系统的主要应力分布区域的应力均值高于常规钉棒系统,但2种钉棒内固定系统连接棒的最大应力值均小于钛合金棒的屈服强度(795-827 MPa)和极限强度(860-896 MPa)。提示新型自行防旋转寰枢椎后路钉棒内固定系统连接棒的设计符合生物力学的要求,新型连接棒是一种有效、安全的脊柱内固定装置,可在临床推广应用。
[Abstract]:Background: posterior atlantoaxial internal fixation is the main method for the treatment of atlantoaxial instability and dislocation, but the connecting rod is cylindrical in the conventional posterior screw rod fixation system. In order to enhance the reduction function, the curvature of the connecting rod is usually large. The connecting rod rotates easily when the nut is fixed, which requires additional control of the auxiliary device and the direction of the fixed connecting rod, but the auxiliary device is occluded by the surgical field. When the auxiliary device is unsteady, it may cause excessive disturbance and accidental injury of the spinal cord. The rotation-resistant atlantoaxial screw rod system is a kind of system which not only maintains the advantages of the conventional screw rod system, but also has the function of self-preventing rotation. But the difference between biomechanical properties and conventional screw rod system needs further study. Objective: to establish a three-dimensional finite element model of posterior atlantoaxial screw rod fixation system. To evaluate the biomechanical characteristics of a new type of self-rotating posterior atlantoaxial screw rod fixation system. Methods: finite element analysis software was used to establish the finite element model of the upper cervical spine posterior screw rod fixation system. The stress distribution cloud diagram of the nail rod internal fixation system is obtained. Results and conclusions: the geometric similarity of the established finite element model is good. The conventional and new screw rod system models contain 198,330 nodes and 964,747 units respectively 246,788 nodes and 996,069 elements. There is no obvious stress concentration in the two internal fixation systems, and the main stress distribution regions are basically the same. The stress distribution in the main stress distribution area of the new self-rotating posterior atlantoaxial screw rod fixation system was higher than that in the conventional screw rod system. However, the maximum stress values of the connecting rods of the two internal fixation systems are lower than the yield strength of titanium alloy rods (795-827 MPa) and the ultimate strength of 860-896 MPA / a. It is suggested that the design of the new type of self-rotation-resistant posterior fixation system for atlantoaxial screw rods meets the requirements of biomechanics. The new connecting rod is an effective and safe device for spinal internal fixation, which can be widely used in clinic.
【作者单位】：解放军第二军医大学研究生院;解放军广州军区广州总医院骨科;
【基金】：国家自然科学基金(81672232) 广东省省级科技计划项目(2015B020233013)~~
【分类号】：R318.01;R687.3

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