骶髂关节解剖型钢板的全骨盆三维有限元模拟

目的在高度仿真的完整骨盆三维有限元模型基础上,模拟使用新设计的解剖型钢板对骶髂关节骨折脱位进行固定,并与普通钢板的模拟固定进行对比,验证和分析新型钢板的性能.方法从CT精确重建髋骨和骶骨模型,采用专门的半自动流线型生物力学有限元网格划分器生成规则的体网格模型,并进一步建立骶髂关节的终板、软骨、关节接触面,和骨盆上的主要韧带组织及耻骨间盘.然后去掉一侧的骶髂关节韧带群模拟骨折脱位,使用新型的骶髂关节解剖型棒-板内固定系统进行固定模拟,同时使用普通钢板替代解剖型钢板建立对比模型,分别进行加载分析受力情况.结果通过使用新的解剖型钢板改进棒一板内固定系统,骶髂关节的最大相对位移值减小了约23%,骨盆主要传承负载区域的最大的应力值降低了约25%.结论新型的解剖型钢板有效地提高了骶髂关节棒-板内固定系统的力学性能,为骨盆骨折的治疗增加了一种更有效的新方法.

3D FE simulation of anatomic plates for sacroliliac joints on whole pevis model

Objective Based on a geometrical and mechanical accurate 3D FE model of whole pelvis,this paper evaluatesthe biomechanical properties of a new sacroliliac bar-plate internal fixation system with anatomic plate,compared to normal rect plate.Methods Using accurate solid models of the sacral and hip bones from CT data,an ad hoc biomechanieal semi-automatic mesh generator was employed to generate regular FE mesh of the pevis model.Sacroiliac joint related end plates,cartilages,and contact surfaces,as well as several important ligaments and the interpubic disc were reeonstucted to consummate the whole model.One side of sacroiliac joint rellated ligaments was deleted to simulate the case of sacroiliac joint fracture.Then the new sacroliliac bar-plate internal fixation system with anatomic plate was integrated to fix the fracture,and acontrol model using normal rect plate was also generated.All models were simulated under salne loading conditions.Results Using the new sacroliliac bar-plate internal fixation system with anatomic plate,the maximal displayment of the sacroiliac joint decreased about23%and the maximal von Mises Stress of several main loading transfer regions decreased about25%.Conclusion The new anatomic plate improves biomechanical properties of the sacroliliac bar-plate interhal fixation system and is a potential new method applicable in clinical use for pelvis fracture.