Three-dimensional finite element analysis of biomechanical characteristics of cancellous screw in different bone densities / 南方医科大学学报

ABSTRACT

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>