骨重建过程下接骨螺钉生物力学性能分析
Biomechanical Analysis of Orthopedic Screw Under Bone Remodeling
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摘要: 为评估骨重建下不同结构参数的钛合金接骨螺钉的生物力学稳定性,本研究建立了6组不同长度与直径的HA型螺钉内固定的骨-钉三维有限元模型,运用用户自定义子程序对植入螺钉后的骨重建过程进行了模拟。研究发现,骨上应力集中于内螺纹凹槽及根部,螺钉应力主要集中在螺纹起始处,整体应力沿着螺钉长轴递减。在骨重建试验过程中,各试验组骨及螺钉应力分布趋势无明显变化,其最大等效应力值出现不同程度的变化,螺钉与松质骨上最大等效应力增加,而皮质骨上最大等效应力值有所下降。Abstract: In order to evaluate the biomechanical stability of titanium alloy screw with different structural parameters under bone remodeling, some three-dimensional finite element models were established and the bone remodeling process after implanting the screw was simulated. Three-dimensional finite element models consist of bone and screw with different lengths and diameters. Bone remodeling process was simulated by user-defined subroutine. It is found that the stress on the bone is concentrated on the groove and root of the internal thread. The screw stress is mainly on the beginning of the thread, and the whole stress decreases along the long axis of the screw. The stress distribution trend of bone and screw did not change significantly during the bone remodeling. The maximum equivalent stress value was different, the maximum equivalent stress on the screw and cancellous bone increased while the maximum equivalent stress value on the cortical bone decreased.