Development of artificial articular cartilage.

为了使表面关节置换术中大多数健康的软骨下骨（对关节的应力降低功能很重要）得以保留，我们试图开发一种人工关节软骨。我们选择的生物材料是聚乙烯醇水凝胶（PVA-H），它是公认的类橡胶稳定凝胶。我们改进了这种凝胶的合成工艺和它的机械性能。我们从对人工关节软骨的实用性方面考察了新改良的PVA-H的各种力学性能。润滑效果;通过对受载玻璃板与试样之间形成的间隙厚度和流体压力变化的测量，PVA-H比聚乙烯（PE）表现出更厚的流体膜和更高的压力。减震效果;我们测量了冲击应力，随时间在试样中传播。与PE相比，PVA-H的峰值应力更低，持续应力时间更长，衰减效果更好。抗拉强度;恒速拉伸哑铃形试样得到的应力-应变曲线表明，PVA-H具有软韧性，PE具有硬韧性。PVA-H（20%含水量）的极限拉伸强度为17MPA， PE的极限拉伸强度为29MPA。PVA-H的变形特征与天然关节软骨相似，从上述结果来看，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.