Development of artificial articular cartilage.

为了使表面关节成形术能够保留最健康的软骨下骨，而软骨下骨在关节的应力降低功能中起着重要的作用，我们试图开发一种人工关节软骨。我们选择了被公认为橡胶类稳定凝胶的聚乙烯醇-水凝胶(PVA-H)作为此类生物材料。我们对该凝胶的合成工艺和力学性能进行了改进。从人工关节软骨的应用角度考察了新型改良型PVA-H的各项力学性能。润滑效应；在测量玻璃板与受载试件之间形成的间隙的厚度和流体压力的变化时，PVA-H表现出比聚乙烯(PE)更厚的液膜压力；减震效果；我们测量了冲击应力，并随时间传递。PVA-H具有比PE更低的峰值应力和更长的持续应力持续时间，这意味着更好的衰减效果。拉伸强度；恒速拉伸哑铃形试件的应力-应变曲线表明，PVA-H具有柔软和韧性，而PE具有硬和韧性。PVA-H(含水率为20%)的极限拉伸强度为17 Mpa，而PE的极限拉伸强度为29 Mpa。PVA-H的变形特征与天然关节软骨相似，可以说PVA-H可能是一种非常有趣和有前途的材料。

In order to resuscitate a surface arthroplasty in which most healthy subchondral bones, important in stress lowering function of the joints, are preserved, we have tried to develop an artificial articular cartilage. We selected as such biomaterial, Polyvinyl-Alcohol-Hydrogel (PVA-H)which had been recognized as rubber-like stable gel. We have improved the synthetic process of this gel and its mechanical properties. We have examined various mechanical properties of new improved PVA-H, from the aspect of its usefulness for artificial articular cartilage.Lubrication effect; On measuring the changes of thickness and fluid pressure of the gap, formed between glass plate and the specimens under loading, PVA-H showed thicker fluid film with higher pressure than polythylene(PE).Shock-absorbing effect; We measured the shocked stress, transmitted through the specimens time dependently. PVA-H showed lower peak stress and longer duration of sustained stress than PE, what means better attenuating effect.Tensile strength; Stress-Strain curve obtained by pulling the dumbbell form specimens under constant speed, showed that PVA-H had soft and tough properties, while PE, hard and tough. Ultimate tensile strength of PVA-H(20%water content)was 17MPA, while that of PE, 29MPA.Deformation characteristics of PVA-H is similar to that of natural articular cartilage and from above mentioned results, it is permissible to say that PVA-H might be very interesting and promising material.