Adaptive Multimode Lubrication in Natural Synovial Joints and Joint Prostheses

本研究的目的是阐明自然滑膜和人工关节的自适应多模式润滑机理。主要包括以下几个方面：1.天然滑膜关节的自适应多模式润滑的研究除弹性流体动力润滑外，还研究了凝胶膜润滑和渗流润滑机理。明胶凝胶模型的往复实验表明，在合适的温度条件下，凝胶膜的沉积和吸附可以降低摩擦力。猪关节软骨的摩擦行为受凝胶膜的影响。用激光共聚焦显微镜观察软骨表面的渗漏行为。摩擦力的降低与PVA水凝胶中的渗漏有关。2.关节假体的自适应多模式润滑研究圆柱形假体和具有柔顺胫骨假体的解剖假体在中等粘度润滑剂的润滑条件下都显示出相当大的弹流动态膜形成。在低粘度条件下，需要自适应多模式润滑机制。利用PVA水凝胶成分对渗流润滑进行了研究，结果表明，渗漏润滑具有较低的摩擦力。采用双圆柱几何设计，建立了行走时的站立和摆动两种模式。3.自然滑膜关节和人工关节润滑模式的临床评价膝关节润滑功能较差的骨关节炎患者存在侧向高加速度的现象。应用鞋垫改善膝关节接触状况，可有效降低侧向推力。

The object of this research is to elucidate the adaptive multimode lubrication mechanism in natural synovial joints and joint prostheses.The following methods were carried out.1.Elucidation of the adaptive multimode lubrication in natural synovial jointsIn addition to the elastohydrodynamic lubrication, the gel-film lubrication and weeping lubrication mechanisms were investigated. The reciprocating tests of gelatin gel models showed the lowering of friction under appropriate temperature condition for sedimentation and adsorption of gel film. Frictional behavior of pig articular cartilage exhibited the influence of gel film. The weeping behavior in cartilage surface was observed by the confocal laser microscope. The lowering of friction was shown in related to the weeping in PVA(poly-vinyl-alcohol) hydrogel.2.Investigation of the adaptive multimode lubrication in joint prosthesesBoth cylindrical knee prosthesis and anatomical one with compliant tibial component exhibited the considerable elastohydrodynamic film formation under lubricated condition with lubricants of medium viscosity. Under low viscosity conditions, the adaptive multimode lubrication mechanism is required. The weeping lubrication was examined by using PVA hydrogel component, showing low friction. The duo-cylindrical geometric design was proposed to establish two modes for the stance and swing phases during walking.3.Clinical evaluation of lubrication mode in natural synovial joints and joint prosthesesThe occurence of high acceleration for lateral direction was observed in patients with osteoarthritis of inferior lubrication function in knee joints. The improvement of contact condition in knee joint by using insole was effective in reducing of lateral thrust.