Fundamental Study on Improvement of Artificial Joint with the Functional Surface structure

这项研究的目的是通过防止高密度聚乙烯(HDP)的磨损不稳定来长期临床使用人工关节，使用摩擦表面的“图案化”。通过销盘摩擦试验系统研究了摩擦表面对HDP的影响，发现表面花纹的引入改善了金属与HDP之间的润滑条件，减少了HDP磨损颗粒的产生，找到了花纹直径和节距的最佳尺寸。在此基础上，我们在髋关节模拟器上进行了花纹股骨头与髋臼之间的摩擦实验。在这一结果中，我们没有发现摩擦系数的下降。但从光学显微镜对摩擦表面的观察可以看出，花纹对良好的润滑效果很好。然而，如果花纹头表面状况不佳，润滑会变得更差。因此，我们必须研究在头部表面和杯面接触面积上进行良好的花纹处理。此外，我们还必须改进我们的模拟器，例如对摩擦面的加载方式。之后的问题是开发新的髋关节模拟器并再次进行实验。

The aim of this study is the long term clinical use of artificial joint by preventing wear dibris of high-density polyethylene (HDP) using "patterning" for frictional surfaces. The effect of frictional surface of the metal (SUS316L,Co-Cr alloy) vs HDP were investigated.From the results of the friction tests with the pin-on-disk experimental system, we found that the introduction of surface patterns enhances lubrication conditions between the metal) and HDP and reduces the creation of wear particles of HDP.The optimum sizes for the diameter and the pitch of the pattern were found. And good lubrication was maintained not in a short time but for a long time during the test.Based on these studies, we experimented the friction tests between the patterned femoral heads and acetabular cups with a hip simulator. In this result, we couldn's find decrease of the coefficient of friction. But the effect of patterning for good lubrication was suggested from the observation of the frictional surfaces with a light microscope. However, if the patterned head had bad condition on surface, lubrication would get worse. Therefore, we have to investigate about the good way of patterning on the surface of head and on the contact area of cup. Moreover we have to improve our simulator, for example the way of loading to friction surface. Then the problem after this are development of the new hip simulator and experiment with it again.