膝关节骨性关节炎生物力学模型及其软骨表面应力分析

A biomechanical model of knee osteoarthritis and stress characteristics on the cartilage surface

背景:膝关节骨性关节炎主要以软骨退变,骨质增生进而影响到关节周围软组织致关节疼痛,负重后加重以及后期致关节变形的慢性疾病。目的:实验收集膝关节骨性关节炎患者及正常人的膝关节影像学参数,再先后导入各种软件建立模型,然后在模型上模拟膝关节下蹲动作,并收集下蹲过程中膝关节骨性关节炎患者及正常人膝软骨表面的应力数据,并将两者进行对比从而得出膝关节骨性关节炎患者软骨表面应力特征。方法:收集膝关节骨性关节炎患者及正常人各30例,通过影像学CT,MRI检查获得数据,将得到的数据通过Mimics软件、Simpleware软件分析后建立模型,通过模型获得膝关节软骨应力相关数据,最后进行膝关节骨性关节炎患者与正常人数据的对比分析,分析总结得出膝关节骨性关节炎患者关节软骨的应力特点。结果与结论:膝关节骨性关节炎患者从站立到下蹲过程中膝软骨表面应力一般呈现非线性递增趋势。膝关节骨性关节炎患者下蹲过程中膝软骨表面中间外侧应力应力高于正常人体组(P<0.05),而其下蹲过程中膝软骨表面靠近远端应力及前后侧应力与正常人相比差异无显著性意义(P>0.05)。结果证实,成功建立膝关节骨性关节炎肌骨模型和有限元模型,建立的模型更接近真实膝关节的运动特征,通过模型为膝关节骨性关节炎疾病提供膝部组织定量的生物力学数据。

BACKGROUND：Knee osteoarthritis is a chronic disease characterized as cartilage degeneration and hyperostosis to impact the soft tissues around the joints, thereby resulting in joint pain, and it can be aggravated and lead to joint deformity after weight-bearing. OBJECTIVE：On the basis of imaging parameters of knee osteoarthritis patients and normal controls, a model was established. And then, knee squatting movement was simulated on the model and stress data from the cartilage surface of patients and normal controls were colected and compared, thereby to obtain the stress characteristics of the cartilage surface in knee osteoarthritis patients. METHODS： There were 30 knee osteoarthritis patients and 30 healthy volunteers in the study. CT and MRI data from these participants were colected and analyzed using Mimics software and simpleware software to establish a model. Based on this model, cartilage-related stress data were harvested from knee osteoarthritis patients and healthy volunteers and compared to summarize the stress characteristics of the articular cartilage in patients with knee osteoarthritis. RESULTS AND CONCLUSION：In knee osteoarthritis patients, the stress on the cartilage surface from standing to squatting was increased in a nonlinear manner. During the process of squatting, the mediolateral stress was higher in the knee osteoarthritis patients than healthy controls （P 〈 0.05）; however, there was no difference in the proximodistal and anteroposterior cartilage surface stress between the two groups （P 〉 0.05）. These findings indicate that the knee osteoarthritis musculoskeletal model and finite element model are established successfuly, and these models are closer to the real motion characteristics of the knee joints, based on which, quantitative biomechanical data of the knee can be provided for knee osteoarthritis treatment.