Flanagan S, Jones E, Birkinshaw C
Department of Materials, Science and Technology, University of Limerick, Limerick, Ireland.
Proc Inst Mech Eng H. 2010;224(7):853-64. doi: 10.1243/09544119JEIM733.
New material combinations and designs of artificial hip implants are being introduced in an effort to improve proprioception and functional longevity. Larger joints in particular are being developed to improve joint stability, and it is thought that these larger implants will be more satisfactory for younger and more physically active patients. The study detailed here used a hip friction simulator to assess the friction and lubrication properties of large-diameter hip bearings of metal-on-metal and ceramic-on-reinforced-polymer couplings. Joints of different diameters were evaluated to determine what effect, if any, bearing diameter had on lubrication. In addition, the effects of lubricant type are considered, using carboxymethyl cellulose and bovine calf serum, and the physiological lubricant is shown to be considerably more effective at reducing friction. The frictional studies showed that the metal-on-metal joints worked under a mixed lubrication regime, producing similar friction factor values to each other. The addition of bovine calf serum (BCS) reduced the friction. The ceramic-on-reinforced-polymer samples were shown to operate with high friction factors and mixed lubrication. When tested with BCS, the larger-diameter bearings showed a decrease in friction compared with the smaller-size bearings, and the addition of BCS resulted in an increase in friction, unlike the metal-on-metal system. The study demonstrated that the component's diameter had little or no influence on the lubrication and friction of the large bearing combinations tested.
为了改善本体感觉和功能寿命，新型人工髋关节植入物的材料组合和设计不断被推出。特别是更大尺寸的关节正在研发中，以提高关节稳定性，人们认为这些更大尺寸的植入物对更年轻、身体更活跃的患者会更令人满意。本文详细介绍的这项研究使用了髋关节摩擦模拟器，来评估金属对金属和陶瓷对增强聚合物联轴器的大直径髋关节轴承的摩擦和润滑特性。对不同直径的关节进行评估，以确定轴承直径对润滑是否有影响，如果有，影响如何。此外，还考虑了润滑剂类型的影响，使用了羧甲基纤维素和小牛血清，结果表明生理润滑剂在减少摩擦方面效果显著得多。摩擦研究表明，金属对金属关节在混合润滑状态下工作，彼此产生的摩擦系数值相似。添加小牛血清（BCS）可降低摩擦力。陶瓷对增强聚合物样本显示出高摩擦系数和混合润滑。在用BCS测试时，与较小尺寸的轴承相比，较大直径的轴承摩擦力降低，而且与金属对金属系统不同，添加BCS导致摩擦力增加。该研究表明，部件的直径对所测试的大轴承组合的润滑和摩擦几乎没有影响。
