Wear Mechanisms in Metal-on-Metal Bearings: The Importance of Tribochemical Reaction Layers
Wear Mechanisms in Metal-on-Metal Bearings: The Importance of Tribochemical Reaction Layers
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DOI：
10.1002/jor.21020
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发表时间：
2010-04-01
影响因子：
2.8
通讯作者：
Jacobs, Joshua J.
中科院分区：
文献类型：
--
作者：
Wimmer, Markus A.;Fischer, Alfons;Jacobs, Joshua J.
金属对金属（MoM）关节面是髋关节表面置换术的前沿。由于其良好的磨损特性和设计灵活性，MoM轴承获得了更广泛的认可，全球市场份额接近10%。然而，人们仍然担心金属颗粒和离子释放的潜在有害影响。越来越多的证据表明，局部细胞反应与这些轴承对产生的碎片量有关。因此，迫切的临床需要描述碎片产生的机制，以进一步减少磨损及其不良影响。在这项研究中，我们调查的微观结构和化学成分的摩擦化学反应层形成在接触表面的金属轴承在滑动运动。使用X-射线光电子能谱和透射电子显微镜与耦合能量色散X-射线和电子能量损失谱，我们发现，摩擦层是纳米晶体的结构，并且它们将有机材料来自滑液。这一过程被称为“机械混合”，将最上面50至200 nm的轴承表面从纯金属变为有机复合材料。它阻止直接金属接触（从而防止粘附）并限制磨损。纳米晶金属和有机成分的机械混合区的这一新发现为理解颗粒释放提供了基础，并可能有助于确定减少MoM磨损的新策略。(C)2009骨科研究学会。出版社：Wiley Periodicals，Inc. J Orthop Res 28：436-443，2010
Metal-on-metal (MoM) bearings are at the forefront in hip resurfacing arthroplasty. Because of their good wear characteristics and design flexibility, MoM bearings are gaining wider acceptance with market share reaching nearly 10% worldwide. However, concerns remain regarding potential detrimental effects of metal particulates and ion release. Growing evidence is emerging that the local cell response is related to the amount of debris generated by these bearing couples. Thus, an urgent clinical need exists to delineate the mechanisms of debris generation to further reduce wear and its adverse effects. In this study, we investigated the microstructural and chemical composition of the tribochemical reaction layers forming at the contacting surfaces of metallic bearings during sliding motion. Using X-ray photoelectron spectroscopy and transmission electron microscopy with coupled energy dispersive X-ray and electron energy loss spectroscopy, we found that the tribolayers are nanocrystalline in structure, and that they incorporate organic material stemming from the synovial fluid. This process, which has been termed "mechanical mixing," changes the bearing surface of the uppermost 50 to 200 nm from pure metallic to an organic composite material. It hinders direct metal contact (thus preventing adhesion) and limits wear. This novel finding of a mechanically mixed zone of nanocrystalline metal and organic constituents provides the basis for understanding particle release and may help in identifying new strategies to reduce MoM wear. (C) 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:436-443, 2010