A Basic Study of Sealed Joint with Artificial Synovial Fluid

研究了一种新型密封型人工关节的基本特性。结果表明，由于人工合成滑液的润滑作用，HDPE套筒的磨损率可能会大大降低。由于人工关节囊捕捉磨损颗粒，因此完全保护了针对HDPE颗粒的生物反应。这项研究的目的是探讨长期使用的密封接头的可能设计。本课题的研究成果如下：(1)采用浇铸法制备了硅橡胶和聚氨酯两种人工关节胶囊。对几种液体的密封性能进行了测试。(2)密封关节的屈伸角度范围超过80度，内外旋转范围超过40度。两种材料的关节囊显示出足够的变形能力，不会限制关节的运动，而硅橡胶关节囊表现出更好的变形能力。(3)对于大变形，抗力矩表现出非线性特征。由于关节囊中心附近有较大的弯矩，有必要对其进行加厚。(5)用销盘式磨损试验机对几种含有蓖麻油的液体进行了磨损试验。加入蓖麻油后，摩擦因数降至0.02，磨损率不到牛血清的1/10。

Basic characteristics of a novel sealed type artificial joint was investigated. The results show that the wear rate of HDPE socket may be drastically reduced due to the lubrication effect of synthetic synovial fluid. Since the artificial joint capsule trapps the wear particles, biological reaction against HDPE particles is completely protected. The purpose of this study was to investigate the possible design of a sealed joint for long term use. The results of this reserach project is as follows ;(1) Two types of artificial joint capsule of silicon rubber or polyurethane were produced by casting. The sealing performamce of these capsules were tested for several kinds of liquid.(2) The range of flexion-extension angle of the sealed joint exceeded 80degrees, and that of external-internal rotation exceeded 40degrees. Joint capsule of both materials showed sufficient deformability not to limit the joint movement, while the joint capsule of silicon rubber showed better deform ability.(3) For large deformation, the resisting moment showed non-linear characteristics. At the same time, buckling phenomenon was observed with wrinkles on its surface.(4) Since large moment was measured near the center of the joint capsule, it is necessary to thicken this place.(5) Wear test was performed with several liquids containing castor oil with a pin-on disk apparatus. The friction coefficient was reduced to be 0.02 with castor oil, and wear rate with castor oil was less than 1/10 of that with bovine serum.