膝关节股骨远端软骨硬化前后力学性能分析

目的建立膝关节有限元模型,研究正常及软骨硬化情况下膝关节的应力、应变变化,为临床治疗膝关节骨性关节炎提供参考。方法通过Mimics、ANSYS等软件结合正常膝关节CT扫描图像数据,建立膝关节三维有限元模型,并施加350 N压力载荷,设定软骨硬化前后相关的材料参数,分析膝关节主要组织的应力、应变改变情况。结果膝关节股骨远端软骨硬化后,关节软骨的减震和传递负荷等作用基本消失;股骨应力、应变变化量最大,受力分布极不均匀,股骨前端应力、应变较内、外侧髁明显,整体受力也有明显增加;半月板的应力、应变值最大。结论长期的软骨破坏会影响关节软骨营养代谢,导致骨性关节炎疾病进一步恶化。研究结果可以较好阐释骨性关节炎发病过程和机理,同时为建立参数化研究系统提供相关数据。

Analysis on mechanical properties of cartilage in distal femur of knee joint under normal and sclerosis case

Objective To establish the finite element model of knee joint and investigate changes of stress and strain in normal and cartilage sclerosis cases, so as to provide reference for clinical treatment of the knee osteoarthritis. Methods CT scanning images of normal knee joint were used to establish the 3D finite model using Mimics and ANSYS software. Loadings of 350 N pressures were applied on the model of normal knee joint and knee joint with cartilage sclerosis, respectively. The related material parameters of cartilage before and after sclerosis were set, and the Von Mises stress and strain changes of the knee joint were then analyzed. Results In case of cartilage sclerosis, the function of shock absorption and load transfer in articular cartilage basically disappeared. The stress and strain on the femur changed with uneven distribution, showing more obviously than those on the inner and outer condyle, and the overall stresses were increased obviously. The largest stress and strain occurred on the meniscus. Conclusions The long-term cartilage destruction will affect nutrient metabolism of articular cartilage and cause the deterioration of osteoarthritis diseases. This study can preferably explain the pathogenic mechanism of osteoarthritis, and also provide relevant data for establishing parametric study system.