Tian Chong, Zhang Mei-chao, Ouyang Jun
Department of Anatomy, Southern Medical University, Guangdong Provincial Medical Biomechanical Key Laboratory Guangdong, Guangzhou 510515, China.
Nan Fang Yi Ke Da Xue Xue Bao. 2010 Nov;30(11):2466-8.
To predict the cancellous screw stress distributions and pull-out strength in cancellous bone with different densities using 3-D finite element analysis and provide biomechanical evidence for screw implant in clinical practices.
Three-dimensional models of bones with low, medium and high bone density and a fixation screw were generated in Solidworks. Finite element analysis was performed after importing these models to Abaqus to simulate the pull- out process.
Stress concentrated both at the surfaces where major diameter of the screw connected the bone and at the proximal half angle of the 3 proximal screw threads. Maximum Von Mises stress of the threads decreased along the long axis of the screw. The pull-out strengths of the cancellous screw were 208.9 N, 431.45 N, and 648.80 N in low, medium and high bone density, respectively.
During the pull-out process of cancellous screw, stress concentrates at the proximal end of the screw and the pull-out strengths are proportional to the cancellous bone density.
采用三维有限元分析预测不同密度松质骨中松质骨螺钉的应力分布和拔出强度，为临床螺钉植入提供生物力学依据。
在Solidworks中生成低、中、高骨密度骨骼及一枚固定螺钉的三维模型。将这些模型导入Abaqus后进行有限元分析，以模拟拔出过程。
应力集中在螺钉大径与骨连接的表面以及近端3个螺纹的近端半角处。螺纹的最大等效应力沿螺钉长轴降低。低、中、高骨密度下松质骨螺钉的拔出强度分别为208.9 N、431.45 N和648.80 N。
在松质骨螺钉拔出过程中，应力集中在螺钉近端，且拔出强度与松质骨密度成正比。
