Shishido T, Clarke I C, Williams P, Boehler M, Asano T, Shoji H, Masaoka T, Yamamoto K, Imakiire A
Orthopaedic Research Center, Department of Orthopaedics, 11406 Loma Linda Drive, Loma Linda, California 92354, USA.
J Biomed Mater Res B Appl Biomater. 2003 Oct 15;67(1):638-47. doi: 10.1002/jbm.b.10048.
Three THAs with cementless monolithic alumina ceramic sockets and cementless Co-alloy stems were retrieved because of aseptic loosening after 17 and 24 years. At revision heads and cups were marked for orientation. Maps were drawn of wear patterns with the use of light microscopy and surveyed by SEM. In a simulator experiment 28-mm-diameter alumina heads and liners were used. The cups were mounted inverted in a hip simulator and run with calf serum as the lubricant. The hip loads were 2 kN maximum and a 1-Hz frequency for 20 million cycles. Wear severity was classified into five grades. In retrieved implants, SEM analysis showed that the main wear zones (MWZ) had Grade 4 wear. The peripheral wear zones (PWZ) showed grain pull-out regions (Grade 5 wear). These corresponded to neck-socket impingement and head-acetabular cup separation. Gray was due to transferred CoCr particles from the stem. In the simulator study, the MWZ had only localized areas of grain pull out surrounded by polished surface regions (Grade 4 wear) at 20 million cycles; stripe wear was not seen. The alumina ceramic bearings proved excellent up to 22 years in simulator studies and clinical studies. However, microseparation kinematics would be necessary in the simulator to duplicate the more peripheral wear zones.
因无菌性松动，在17年和24年后取出了3例采用非骨水泥整体式氧化铝陶瓷髋臼杯和非骨水泥钴合金股骨柄的全髋关节置换术（THA）假体。翻修时，对股骨头和髋臼杯进行了定向标记。利用光学显微镜绘制磨损模式图，并通过扫描电子显微镜（SEM）进行观察。在模拟器实验中，使用了直径28mm的氧化铝股骨头和内衬。将髋臼杯倒置安装在髋关节模拟器中，以小牛血清作为润滑剂进行运行。髋关节最大负荷为2kN，频率为1Hz，运行2000万次循环。磨损严重程度分为五个等级。在取出的假体中，SEM分析显示主要磨损区域（MWZ）有4级磨损。周边磨损区域（PWZ）出现了颗粒拔出区域（5级磨损）。这些对应于股骨颈-髋臼杯撞击和股骨头-髋臼杯分离。灰色是由于钴铬颗粒从股骨柄转移所致。在模拟器研究中，在2000万次循环时，MWZ仅出现局部颗粒拔出区域，周围为抛光表面区域（4级磨损）；未观察到条纹磨损。在模拟器研究和临床研究中，氧化铝陶瓷轴承在长达22年的时间里表现出色。然而，在模拟器中需要采用微分离运动学来模拟更多的周边磨损区域。
