关节软骨的生物摩擦学机理研究

发布时间：2018-03-22 16:03

本文选题：关节软骨　切入点：生物摩擦学　出处：《上海交通大学》2014年博士论文　论文类型：学位论文

【摘要】：关节软骨是一层具备优异润滑性能和承载能力的组织，在人体关节正常运行中起到了非常重要的作用。软骨严重损伤后人工关节置换是最后的治疗手段。但对于同样的软骨对金属关节摩擦副，半髋人工关节置换比不置换髌骨的人工膝关节置换的术后效果差得多，所以有必要对关节磨损方式，关节软骨损伤的形成和发展过程进行研究，从而为关节软骨损伤的早期诊断和治疗提供支持。本课题以关节软骨的生物力学计算作为理论工具研究了软骨的间质流动。其次结合同步辐射相衬成像和示踪剂，对关节软骨内的间质流动情况进行了实验验证。另外通过软骨的摩擦实验分析了软骨的两相润滑模式等摩擦磨损行为。最后将上述三方面研究结果提炼成软骨损伤的生物摩擦学机理，并运用它对半髋人工关节置换与不置换髌骨的人工膝关节置换中的生物摩擦学问题进行了分析。本课题研究获得的主要内容和结论有以下几点：第一，以软骨两相力学模型为基础，在COMSOL中建立了软骨力学模型。结合软骨的蠕变实验测量了软骨力学参数，得到的软骨弹性模量为1MPa，渗透率为2.2×10-14m4/Ns。采用这些参数计算了静载荷，平移载荷和循环载荷下软骨内部间质流动，并建立了软骨细胞跨尺度力学计算方法。通过软骨流动电势测量实验对以上软骨生物力学模型进行了验证，得到的实验结果与模型计算结果相一致。第二，在上海光源开展了软骨间质流动的实验验证。首先筛选出合适的软骨造影剂，测定了它在软骨中一维扩散的扩散系数为2.28×10-11m2/s±0.71×10-11m2/s。基于以上数据和经验，分析了软骨间质流动验证实验面临的难点，并提出了实验技术方案。使用软骨力学模型对技术方案进行了理论分析并进行了预实验验证，优化了参数。最后对正常软骨组和OA软骨组的间质流动进行了实验。两组软骨样本循环载荷下的间质流动模式存在较大差异。第三，根据软骨对软骨摩擦实验和力学计算，，软骨的摩擦系数的上升与软骨表面间质液承载比例的下降直接相关。载荷的移动速度对维持软骨表面间质液承载比例有显著影响。另一方面，DPPC脂质体头部基团带正电，软骨的负表面电势促进脂质体的吸附，有利于润滑；而正表面电势排斥脂质体，使润滑环境恶化。第四，关节软骨摩擦磨损是以软骨润滑机制的失效和以疲劳磨损为主的表面损伤开始的，过多间质液渗入软骨中，引发软骨内生物大分子降解的恶性循环。运用软骨细胞跨尺度力学计算分析了正常软骨和OA软骨细胞周边的力学环境，结果表明正常软骨细胞的力学计算结果与文献实验中取得的结果一致。相反OA软骨细胞的力学计算结果远远偏离正常范围，严重影响了软骨细胞正常生理功能，这与OA软骨组织切片观察到的表现一致。最后，半髋人工关节置换与不置换髌骨的人工膝关节置换两者术后结果差异主要原因是半髋置换破坏了原来的移动接触润滑模式，髋臼软骨在金属球头固定接触下的摩擦系数将大幅升高；其次，挤压膜计算也显示半髋置换后的挤压膜持续时间比天然髋关节下降了62%。髌骨凭借自身的滑移运动保证了移动接触的润滑模式，能够维持低水平的摩擦系数。半髋置换在上述摩擦磨损的情况下，软骨细胞力学环境有恶化趋势。不置换髌骨的人工膝关节置换术的软骨细胞力学环境与天然髋关节的细胞力学环境基本相同。本课题将软骨摩擦学向软骨生理学进行了延伸，通过软骨生物力学模型和软骨细胞的跨尺度力学计算，把软骨的力学损伤与其造成的软骨病理现象联系在了一起，为以后这方面的跨学科研究提供了支持。
[Abstract]:Articular cartilage is a layer with excellent lubrication performance and bearing capacity of the organization, in the human body joint normal operation plays a very important role in cartilage. Serious injury after artificial joint replacement is the final treatment. But for the same cartilage to metal joint friction, semi hip arthroplasty than artificial knee joint replacement is not the replacement of the patella postoperative effect is much less, so it is necessary to study the abrasion of the joint, the process of formation and development of articular cartilage injury, so as to provide support for the early diagnosis and treatment of articular cartilage injury.
The biomechanics of articular cartilage interstitial flow calculation as a theoretical tool to study cartilage. Secondly combined with synchrotron radiation imaging and tracer, interstitial flow of articular cartilage in the experiment. The other two modes of lubrication friction and wear behavior of cartilage were analyzed by friction experimental cartilage. The last of the three the research results into the biotribological mechanism of cartilage injury, biotribology problem of artificial knee joint replacement and its application on hip arthroplasty and no patella replacement in were analyzed.
The main contents and conclusions of this research are as follows:
First, the mechanical model of two-phase cartilage based on COMSOL in cartilage mechanics model is established. Combining with the creep experiments of cartilage mechanics parameters were measured, the elastic modulus of cartilage was obtained 1MPa, permeability of 2.2 * 10-14m4/Ns. with these parameters of static load calculation, internal cartilage interstitial fluid flow under translational load and cycle load, and the establishment of the cartilage cells cross scale mechanical calculation method. Through the streaming potential measurement experiment to verify the cartilage cartilage biomechanics model above the experimental results obtained, the calculation results are consistent with the model.
Second, in Shanghai to carry out light cartilage interstitial fluid flow experiment. First screening suitable cartilage contrast agent, determination of the diffusion coefficient in the cartilage in the one-dimensional diffusion is 2.28 * 10-11m2/s + 0.71 * 10-11m2/s. based on the above data and experience, analysis of the cartilage interstitial fluid flow verification the difficulties faced, and put forward the technical scheme. Using the technical scheme of cartilage mechanics model analysis and pre experiment, optimized parameters. Finally, interstitial flow of normal cartilage and OA cartilage group group in the experiment. There is a big difference between the two groups of interstitial flow pattern of cartilage samples under cyclic loading.
Third, according to the cartilage on cartilage friction test and mechanical calculation, the friction coefficient of the surface of cartilage and cartilage increased between the decreased fluid carrying ratio is directly related to the moving speed. The load has a significant impact on the maintenance of cartilage surface interstitial fluid bearing ratio. On the other hand, DPPC liposomes with the positively charged head groups, negative surface potential of cartilage to promote the adsorption of liposome, is conducive to lubrication; while the positive surface potential exclusion of liposome, the lubricating environment deterioration.
Fourth, the friction and wear of articular cartilage with cartilage lubrication mechanism and failure to start the fatigue wear surface damage, excessive infiltration of interstitial fluid in cartilage, lead to vicious spiral biological macromolecules cartilage degradation. The cartilage cells cross scale mechanical calculation analysis of mechanical environment of normal cartilage and OA cartilage cells surrounding. The results show that the normal cartilage cells made mechanical calculation results and experimental results in the literature. On the contrary mechanical chondrocyte OA results far from the normal range, seriously affected the normal physiological function of cartilage cells, cartilage tissue and the OA observed were consistent.
Finally, semi hip arthroplasty and patella replacement without artificial knee joint replacement both postoperative result difference is the main reason for hip replacement destroyed the original mode of moving contact lubrication, the friction coefficient of acetabular cartilage in contact with the fixed metal ball head under will be significantly increased; secondly, the squeeze film results also show that the squeeze film semi hip replacement after the last longer than natural hip decreased 62%. with patella sliding motion itself to ensure the lubrication mode of the mobile contact, can maintain a low coefficient of friction at the level of hip replacement in the friction and wear conditions, soft bone cell mechanics environment has deteriorated. The cell mechanical environment of chondrocyte mechanics environment artificial knee joint replacement the operation of patella replacement and natural hip joint is basically the same.
The cartilage physiology of cartilage tribology to extend through the cross scale mechanical cartilage chondrocytes biomechanical model and calculation, to cartilage pathological phenomenon of mechanical damage of cartilage and the resulting together, for future interdisciplinary research in this area provides support.

【学位授予单位】：上海交通大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：R684;R318.01

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