- 期刊
Combined Use of the CAD System and Finite Element Method to Investigate the Biomechanical Effect of the Pedicle Screw
結合CAD系統及有限元素方法探討椎弓骨釘之生物力學
並列摘要
Pedicle screw fixation systems are commonly used in orthopedic surgical procedures to treat unstable spines. Recent clinical surveys have reported that the major failure modes of the pedicle screw fixation system are screws failure and vertebral body breakage. To avoid these failures, batter understanding of the mechanical environment within the body and the implanted screws is essential. This study employed a three-dimensional finite element (FE) spine model to investigate the load transfer between the pedicle screw and the pedicle screw and the meshing process A CAD (computer –aided design) system was integrated into the meshing process to simulate the screw implantation procedure. The results showed that the major loading mode of the screw occurred during bending and that the peak stress region was located right before the first thread, which is consistent with site locations of clinically observed screw failures. In the analysis, we used a model of the screw within the vertebra that took into account the geometry of the screw thread and the contact element. The latter was a simulation of the screw-vertebra interface, which has been neglected by other finite element simulations.