新型骶髂关节内固定系统的三维仿真与对比验证

目的 建立使用新型的骶髂关节解剖型棒-板内固定系统（SABP）对骶髂关节骨折脱位进行固定的三维有限元模型，并与骶髂关节螺钉、和前路重建钢板固定进行对比，验证和分析其力学性能。 方法 根据CT扫描数据，采用专门的流线型生物力学有限元网格划分器，建立完整骨盆三维有限元模型。去掉模型一侧的骶髂关节韧带群模拟骨折脱位，使用新型的SABP内固定系统进行固定模拟，同时分别使用骶髂关节螺钉（SS）和前路重建钢板固定（SP）建立对比模型，进行加载计算，分析受力情况。 结果 SABP 固定的最大位移值比 SS固定减小约40%，比 SP固定减小约42%。与对照组相比，SABP 固定模型中，在主要传承负载区域的最大Stress 值均为最小：在损侧髋皮质骨、和损侧髋软骨区域， 比SS固定减小约 33%-70%；在骶皮质骨、和损侧髋皮质骨区域，比SP固定减约 60%-75%。 结论 新型骶髂关节解剖型棒-板内固定系统的固定形式更趋合理，固定结构更趋稳定，为骨盆骨折的治疗增加了一种更有效的新方法。

3D Simulation of New Sacroliliac Internal Fixation System and Comparing Evaluation

Objective Creating a 3D finite element model of a full pelvis with sacroiliac joint fracture. Comparing the biomechanical properties of the model where the fracture part was fixated by using a new sacroliliac anatomy type Bar-plate internal fixation system to iliosacral screw fixation and front reconstruction plate fixation. Methods A specially designed biomechanical semi-automatic mesh generator was employed to generate the complete pelvis finite element model from CT datas. Then, one side of sacroiliac joint related ligaments was deleted to simulate the case of sacroiliac joint fracture. Using a new sacroliliac bar-plate internal fixation system with anatomic plate (SABP) to fix the fracture part, and the comparing models using iliosacral screw fixation (SS) and front reconstruction plate fixation (SP) were also generated. Finally, all models were simulated under same loading conditions. Results Using SABP fixation, the maximal displayment of the sacroiliac joint decreases about 40% and 42% compared to SS fixation and SP fixation, respectively. The minimal value of maximal stress for main loading transfer regions was reached by SABP fixation and t he maximal stress of SABP decreases about 33%-70% compares to SS in regions of fracture hip cortical bone and cartilages bone, and decreases about 60%-75% to SP in regions of sacral cortical bone and fracture hip cortical bone. Conclusion The new sacroliliac anatomy type Bar-plate internal fixation system has better biomechanical properties than other internal fixations, and deserves to be put into clinical application.