Al-Hajjar Mazen, Jennings Louise M, Begand Sabine, Oberbach Thomas, Delfosse Daniel, Fisher John
Institute of Medical and Biological Engineering, School of Mechanical Engineering University of Leeds, Leeds, UK.
J Biomed Mater Res B Appl Biomater. 2013 Nov;101(8):1456-62. doi: 10.1002/jbm.b.32965. Epub 2013 Jun 7.
Further development of ceramic materials for total hip replacement aim to increase fracture toughness and further reduce the incidence of bearing fracture. Edge loading due to translational mal positioning (microseparation) has replicated stripe wear, wear rates, and bimodal wear debris observed on retrievals. This method has replicated the fracture of early zirconia ceramic-on-ceramic bearings. This has shown the necessity of introducing microseparation conditions to the gait cycle when assessing the tribological performance of new hip replacement bearings. Two novel ceramic matrix composite materials, zirconia-toughened alumina (ZTA) and alumina-toughened zirconia (ATZ), were developed by Mathys Orthopädie GmbH. In this study, ATZ-on-ATZ and ZTA-on-ZTA bearing combinations were tested and compared with alumina-on-alumina (Al2O3-on-Al2O3) bearings under adverse microseparation and edge loading conditions using the Leeds II physiological anatomical hip joint simulator. The wear rate (±95% confidence limit) of ZTA-on-ZTA was 0.14 ± 0.10 mm(3)/million cycles and that of ATZ-on-ATZ was 0.06 ± 0.004 mm(3)/million cycles compared with a wear rate of 0.74 ± 1.73 mm(3)/million cycles for Al2O3-on-Al2O3 bearings. Stripe wear was evident on all bearing combinations; however, the stripe formed on the ATZ and ZTA femoral heads was thinner and shallower that that formed on the Al2O3 heads. Posttest phase composition measurements for both ATZ and ZTA materials showed no significant change in the monoclinic zirconia content. ATZ-on-ATZ and ZTA-on-ZTA showed superior wear resistance properties when compared with Al2O3-on-Al2O3 under adverse edge loading conditions.
用于全髋关节置换的陶瓷材料的进一步发展旨在提高断裂韧性并进一步降低轴承断裂的发生率。由于平移位置不当（微分离）导致的边缘载荷已重现了在取出物上观察到的条纹磨损、磨损率和双峰磨损碎屑。该方法已重现了早期氧化锆陶瓷对陶瓷轴承的断裂情况。这表明在评估新型髋关节置换轴承的摩擦学性能时，有必要在步态周期中引入微分离条件。马西斯矫形有限公司开发了两种新型陶瓷基复合材料，氧化锆增韧氧化铝（ZTA）和氧化铝增韧氧化锆（ATZ）。在本研究中，使用利兹II型生理解剖髋关节模拟器，在不利的微分离和边缘载荷条件下，对ATZ对ATZ和ZTA对ZTA轴承组合进行了测试，并与氧化铝对氧化铝（Al2O3对Al2O3）轴承进行了比较。ZTA对ZTA的磨损率（±95%置信限）为0.14±0.10立方毫米/百万次循环，ATZ对ATZ的磨损率为0.06±0.004立方毫米/百万次循环，而Al2O3对Al2O3轴承的磨损率为0.74±1.73立方毫米/百万次循环。所有轴承组合上都有明显的条纹磨损；然而，在ATZ和ZTA股骨头表面形成的条纹比在Al2O3股骨头表面形成的条纹更薄、更浅。对ATZ和ZTA材料进行的测试后相组成测量表明，单斜氧化锆含量没有显著变化。在不利的边缘载荷条件下，ATZ对ATZ和ZTA对ZTA与Al2O3对Al2O3相比，具有更好的耐磨性能。
