个性化全骨盆三维有限元建模及骶髂关节骨折脱位模拟

目的建立高度仿真的个性化的完整骨盆三维有限元模型,并在此基础上进行骶髂关节骨折脱位的模拟。方法从CT精确重建独立的左、右髋骨和骶骨实体模型,根据髋骨和骶骨的外形特征,利用专门的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。在建立的完整模型上去掉一侧的骶髂关节韧带群进行骨折脱位模拟,并与正常的情况进行对比。结果建立了高精度的个性化全骨盆的三维有限元模型,包括左右髋骨和骶骨的皮质骨、松质骨,骶髂关节的终板、软骨和带摩擦的关节接触面,韧带包括骶髂骨间韧带、骶髂前韧带、骶髂后韧带、骶棘韧带、骶结节韧带、耻骨上韧带和耻骨弓状韧带,以及耻骨间盘。正常模型的加载模拟和骶髂关节骨折脱位模拟的预测结果均与文献试验生物力学结果相符合。结论利用专门的生物力学有限元建模工具能建立更复杂更精确的三维有限元模型,成为全骨盆生物力学分析研究的平台和基础。

Patient-specific FE modeling of whole pelvis and simulation of sacroiliac joint fracture

Objective To create a geometrical and mechanical accurate patient-specific 3D FE model of whole pelvis, and based on which simulate a common case of sacroiliac joint fracture.M ethods The individual geometry of the sacral and hip bones were well reproduced by CT data and then an ad hoc biomechanical semi-automatic mesh generator, which could take the advantage of pairs of frame curves capturing the bone shape feature, was employed to generate regular FE mesh of the pevis model. The sacroiliac joint related end plates, cartilages, and contact surfaces, as well as several important ligaments and the interpubic disc were finally reconstucted to consummate the whole model.R esults A realistic individual FE model of whole pelvis was constructed, including the cortical and trabecular bone of the sacral and hip bones, all anatomical features of sacroiliac joint: end plates, cartilages, and contact surfaces having friction, as well as interosseous sacroiliac ligament, anterior sacroiliac ligament, posterior sacroiliac ligament, sacrospinous ligament, sacrotuberous ligament, superior pubic ligament, arcuate pubic ligament, and the interpubic disc. The simulation results from this normal whole model undering loading as well as the case of sacroiliac joint fracture were closely correlated with published results of experimental biomechanics.C onclusion By a specifically designed biomechanical modeling tool, an accurate individual FE model of whole pelvis including almost all complex anatomical features was generated, which could be used as the foundation for biomechanical analysis of the whole pelvis structure.