Pappas M J, Makris G, Buechel F F
Mechanical Engineering Department, New Jersey Institute of Technology, Newark 07102, USA.
Clin Orthop Relat Res. 1995 Aug(317):64-70.
Wear is a major late complication of total joint arthroplasty, particularly for younger, active patients. Many patients could produce > 40 million motion cycles after joint replacement. Based on current experience and testing, typical joint prostheses are likely to wear out, and need revision in such patients. One problem is degradation of the metal (counterface) surface. A harder, more abrasion resistant, counterface surface is needed. This study evaluated the long-term wear of the titanium nitride ceramic film against ultra high molecular weight polyethylene. In this test, 4 47-mm femoral cups with a polished 8-micron-thick titanium nitride coating were run against 4-mm-thick metal-backed polyethylene bearings machined from GUR415 extruded rod in water at 37 degrees C at 5 Hz and a 2200-N fluctuating load. Wear of the counterface and bearing were extremely low. The average maximum reduction in thickness of the polyethylene was < 0.02 mm, and < 2 microns in the ceramic film. The average polyethylene wear rate was only approximately 2% of that found in a similar test using 32-mm cobalt chromium femoral heads. The titanium nitride-polyethylene couple has great potential as a lifetime bearing combination.
磨损是全关节置换术的主要晚期并发症，对于年轻、活跃的患者尤其如此。许多患者在关节置换后能够产生超过4000万次运动循环。根据目前的经验和测试，典型的关节假体可能会磨损，并且这类患者需要进行翻修手术。一个问题是金属（配对面）表面的降解。因此需要一个更硬、更耐磨的配对面。本研究评估了氮化钛陶瓷膜与超高分子量聚乙烯的长期磨损情况。在该测试中，4个带有8微米厚抛光氮化钛涂层的47毫米股骨杯，与由GUR415挤出棒加工而成的4毫米厚金属背衬聚乙烯轴承，在37℃的水中，以5Hz的频率和2200N的波动载荷进行磨合。配对面和轴承的磨损极低。聚乙烯厚度的平均最大减少量小于0.02毫米，陶瓷膜小于2微米。聚乙烯的平均磨损率仅约为使用32毫米钴铬股骨头进行的类似测试中磨损率的2%。氮化钛 - 聚乙烯配对组合作为一种终身轴承组合具有巨大潜力。
