Halim T, Clarke I C, Burgett-Moreno M D, Donaldson T K, Savisaar C, Bowsher J G
Loma Linda University, 900 E Washington St, Suite 200, Colton, 92324, California, USA.
Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, Maryland 20993-0002, USA.
Bone Joint Res. 2014 Mar;4(3):29-37. doi: 10.1302/2046-3758.43.2000332.
Third-body wear is believed to be one trigger for adverse results with metal-on-metal (MOM) bearings. Impingement and subluxation may release metal particles from MOM replacements. We therefore challenged MOM bearings with relevant debris types of cobalt-chrome alloy (CoCr), titanium alloy (Ti6Al4V) and polymethylmethacrylate bone cement (PMMA).
Cement flakes (PMMA), CoCr and Ti6Al4V particles (size range 5 µm to 400 µm) were run in a MOM wear simulation. Debris allotments (5 mg) were inserted at ten intervals during the five million cycle (5 Mc) test.
In a clean test phase (0 Mc to 0.8 Mc), lubricants retained their yellow colour. Addition of metal particles at 0.8 Mc turned lubricants black within the first hour of the test and remained so for the duration, while PMMA particles did not change the colour of the lubricant. Rates of wear with PMMA, CoCr and Ti6Al4V debris averaged 0.3 mm(3)/Mc, 4.1 mm(3)/Mc and 6.4 mm(3)/Mc, respectively.
Metal particles turned simulator lubricants black with rates of wear of MOM bearings an order of magnitude higher than with control PMMA particles. This appeared to model the findings of black, periarticular joint tissues and high CoCr wear in failed MOM replacements. The amount of wear debris produced during a 500 000-cycle interval of gait was 30 to 50 times greater than the weight of triggering particle allotment, indicating that MOM bearings were extremely sensitive to third-body wear. Cite this article: Bone Joint Res 2015;4:29-37.
人们认为三体磨损是金属对金属（MOM）轴承出现不良后果的一个诱因。撞击和半脱位可能会使MOM置换物释放金属颗粒。因此，我们用钴铬合金（CoCr）、钛合金（Ti6Al4V）和聚甲基丙烯酸甲酯骨水泥（PMMA）的相关碎片类型对MOM轴承进行了挑战。
在MOM磨损模拟试验中加入水泥薄片（PMMA）、CoCr和Ti6Al4V颗粒（尺寸范围为5微米至400微米）。在五百万次循环（5 Mc）试验期间，每隔十个时间间隔插入5毫克碎片配给物。
在清洁试验阶段（0 Mc至0.8 Mc），润滑剂保持黄色。在0.8 Mc时添加金属颗粒，在试验的第一个小时内润滑剂就变成了黑色，并且在整个试验期间一直保持黑色，而PMMA颗粒没有改变润滑剂的颜色。PMMA、CoCr和Ti6Al4V碎片的磨损率平均分别为0.3立方毫米/Mc、4.1立方毫米/Mc和6.4立方毫米/Mc。
金属颗粒使模拟器润滑剂变黑，MOM轴承的磨损率比对照PMMA颗粒高出一个数量级。这似乎模拟了失败的MOM置换物中黑色的关节周围组织和高CoCr磨损的发现。在500000次步态循环间隔期间产生的磨损碎片量比触发颗粒配给物的重量大30至50倍，表明MOM轴承对三体磨损极其敏感。引用本文：《骨关节研究》2015年；4：29 - 37。
