Merritt K, Brown S A
Division of Life Sciences, Food and Drug Administration, Center for Devices and Radiologic Health, Office of Science and Technology, Rockville, MD, USA.
Clin Orthop Relat Res. 1996 Aug(329 Suppl):S233-43. doi: 10.1097/00003086-199608001-00020.
Replacement hip arthroplasty with the use of ultrahigh molecular weight polyethylene for the cup articulating with a metal head has provided a low friction arthroplasty with years of success. However, the search for improved materials and designs for articulating surfaces continues. The use of metallic heads articulating with metallic cups is now being reconsidered for total hip replacements. Success will be enhanced if wear and corrosion of the articulating surfaces can be kept below that of the metal on ultrahigh molecular weight polyethylene couple. Concern has been raised about the release, and biologic fate, of metal species from corrosion and wear. Titanium alloys have been shown to have limitations as an articulating surface showing significant wear, and the alloy per se should not be considered for wear couples in total hip replacements. The cobalt chromium alloys are known to have reasonable wear and corrosion properties and continue to be evaluated. The issue of cobalt chromium wear and corrosion products and how this relates to the biologic performance of total hip replacement devices is reviewed. Under the condition of wear as currently experienced at the articulating surfaces of cobalt chromium alloys and ultrahigh molecular weight polyethylene, the amount of metallic products transferred to the tissues is sufficiently low to be well tolerated by the biologic system. Nickel and cobalt ions arc, rapidly transported from the implant site and eliminated in the urine. Chromium is stored in the tissue and eliminated more slowly. The issue of host hypersensitivity to these elements remains of concern. All 3 elements, in ionic form, are known to cause contact dermatitis. Untoward biologic reactions, including hypersensitivity, should be minimized if wear and corrosion phenomena are minimized.
使用超高分子量聚乙烯制作髋臼杯与金属股骨头相配合的人工髋关节置换术已实现了多年的低摩擦成功置换。然而，人们仍在继续探索用于关节表面的改良材料和设计。目前正在重新考虑在全髋关节置换中使用金属股骨头与金属髋臼杯相配合的方式。如果关节表面的磨损和腐蚀能够保持在低于金属与超高分子量聚乙烯配对的水平，那么手术成功率将会提高。人们对金属腐蚀和磨损产生的金属离子释放及其生物学转归表示担忧。钛合金作为关节表面材料已显示出局限性，存在明显磨损，因此在全髋关节置换中，该合金本身不适合作为磨损配对材料。钴铬合金具有合理的耐磨和耐腐蚀性能，仍在接受评估。本文综述了钴铬合金磨损和腐蚀产物的问题，以及这与全髋关节置换装置生物学性能的关系。在钴铬合金和超高分子量聚乙烯关节表面目前所经历的磨损条件下，转移到组织中的金属产物量足够低，生物系统能够很好地耐受。镍和钴离子会迅速从植入部位转运并通过尿液排出。铬则储存在组织中，排出速度较慢。宿主对这些元素的超敏反应问题仍然令人担忧。已知这三种元素的离子形式都会引起接触性皮炎。如果将磨损和腐蚀现象降至最低，那么包括超敏反应在内的不良生物学反应也应降至最低。
