基于有限元分析骨盆前后倾斜对髋关节应力的影响

Analysis of the influence of anterior and posterior pelvic tilt on the stress of hip joint based on finite element method

目的:通过有限元技术构建骨盆前后倾斜模型并分析其对髋部接触应力的影响。方法:选择1名健康女性志愿者,CT扫描获得骨盆和股骨数据并用于重建髂骨和股骨几何模型,通过曲面增厚建立髋臼软骨和股骨头软骨的独立模型。几何模型装配通过调节髂骨矢状面角度构建骨盆前倾20°和后倾20°模型,所有几何模型导入有限元分析软件完成参数设定。模拟人体站立位于股骨远端施加900 N,进行有限元求解。结果:所有模型顺利求解,应力云图结果显示髋关节CPRESS接触应力分布于股骨头顶部及髋臼穹顶部。对比中立位模型,骨盆前倾后头臼接触峰值应力区向后外侧移动,骨盆后倾后向前内侧移动。骨盆前后倾斜后峰值应力区平均应力较中立位增加,差异有统计学意义(P<0.05)。结论:有限元仿真揭示了骨盆前后倾斜对髋关节接触应力的影响,理论上阐明了该问题可能带来的潜在危害,临床上必须重视骨盆前后倾斜并采取措施纠正。

Objective:To construct anterior and posterior pelvic til-tfinite element models,and analyze the influence on contact stress of hip.Methods:A healthy female volunteer was selected and the CT data of pelvis and femur were obtained to reconstruct the geometric models of ilium and femur,and the independent models of acetabular cartilage and femoral head cartilage were established by curved surface thickening.After geometric components were assembled,the anterior and posterior pelvic tilt 20°models were constructed by adjusting the sagittal angle of the ilium,and all the geometric models were imported into the finite element analysis software to complete the parameter setting.The 900 N was applied to simulate the human body standing at the distal end of the femur,withfinite element solution.Results:All models were with successful solution.The results of stress cloud map showed that the CPRESS contact stress of the hip joint was distributed at the top of the femoral head and acetabular dome.Compared with the neutral model,the peak stress area moved to the posterolateral side in anterior pelvic tilt,and that moved forward and medially in posterior pelvic tilt.The average stress in the peak stress area after the anterior and posterior tilt was higher than that in the neutral model,with statistical significance(P<0.05).Conclusion:The finite element simulation reveals the influence of the anterior and posterior pelvic tilt on the contact stress of the hip joint,and theoretically illustrates the potential harm that this problem may bring,so we must pay attention to taking measures to correct it.