松质骨拉力螺钉紧固过程的隐式动力分析

目的 利用有限元隐式动力学分析方法对拉力螺钉的紧固过程进行动态模拟，分析其骨-钉界面应力分布特征。方法 建立螺钉和周围骨性结构的有限元模型，利用有限元隐式求解器对拉力螺钉的紧固过程进行隐式动力学分析。根据螺钉及周围骨性结构的应力、分布情况分析骨-钉界面受力特征。结果 螺钉螺纹杆部近端为应力集中区域。螺钉周围骨性结构的高应力分布区域位于螺钉螺纹周缘向外区域，深度约相当于螺纹深度。此区域是抵抗螺钉滑脱的主要区域。结论 隐式动力学分析方法可准确模拟螺钉紧固过程中骨-钉界面的力学特性；螺钉周围骨质高应力分布区域的发现有助于进一步理解并改进螺钉的稳定性。
Objective To simulate the tightening procedure of a cancellous lag screw by using the implicit dynamic analysis method, and to evaluate the stress distributions on the screw-bone interface. Methods Finite element models of a lag screw with the surrounding bone were developed, and the implicit solver was set up for implicit dynamic analysis on the tightening procedure of the lag screw. The mechanical properties of the screw-bone interface were also analyzed according to strain and stress distributions on the screw and the surrounding bone. Results The stress of the lag screw was mainly distributed in the proximal portion of the screw thread rod. The high-stress region of the bone around the screw was located outside the outer edge of the screw, and it was approximately equal to the depth of the thread. The area of high-stress distributions on the bone was the main region that resisted screw stripping. Conclusions The method of implicit dynamic analysis can accurately simulate the mechanical properties of the screw-bone interface during screw tightening. The discovery of high-stress distributions on the surrounding bone can help researchers to further understand and improve the stability of screw insertion.