基于有限元方法的正常和早期OA膝关节生物力学行为比较

The Biomechanics Behavior Comparison Between Intact and Early OA Knee Based on the Finite Element Method

目的:通过有限元方法,比较正常和早期骨关节炎(Osteoarthritis,OA)膝关节生物力学行为的不同,以阐明力学因素在膝0A发展过程中的作用。方法:以人体膝关节CT和MRI影像数据为基础,分别构建10例正常和10例早期0A的膝关节三维有限元模型。通过力学仿真观察正常和早期0A膝关节的生物力学行为特征,以关节软骨、半月板的受力接触面积、Von Mises应力峰值、挤压应力峰值为研究指标,比较正常和早期OA膝关节的应力分布差异。结果:早期0A膝关节中内侧间室股骨软骨、内侧半月板的Von Mises应力和挤压应力峰值均高于正常膝关节。早期0A和正常膝关节胫骨软骨的应力峰值无明显差异:早期0A膝关节内侧关节间室接触面积高于正常膝关节,而外侧关节间室无明显差异。结论:早期0A膝关节较正常膝关节存在内侧间室应力明显增加和接触面积增大的特点,这种应力分布特征差异可能是膝0A发展的力学因素。

Objective：In order to clarify the role of mechanical factors in the development of OA of the knee, the aim of this study was to compare cartilage biomechanics characteristics between intact knee joints and early OA knee joints using subject-specific finite element （FE） modeling. Methods：The computed tomography and magnetic resonance imaging image data of knee joint were recruited and imaged：10 with intact knee joints and 10 with mild OA knee joints. FE models were constructed using a validated protocol. The peak Von mises and minimal principal stresses of cartilage and meniscus were compared between groups, and apply statistical methods to analyze the results. Results： In early OA knee, the peak Von mises and minimal principal stresses of cartilage and meniscus were significantly higher than normal medial femoral medial meniscus and articular cartilage of the knee, p〈0.05;the stresses of medial tibial plateau articular cartilages were not significantly changes. The contact areas of medial compartment in early OA knees were significantly higher than intact knee joints, and no obvious difference was found between the lateral joint compartments. Conclusions：The studies have shown that there were significantly higher stress concentration and increased contact area in early OA knee medial compartment than intact knee, these characteristic differences may be the mechanical factors for the development of knee OA.