Tipper J L, Galvin A L, Williams S, McEwen H M J, Stone M H, Ingham E, Fisher J
Institute of Medical and Biological Engineering, University of Leeds, Leeds, United Kingdom.
J Biomed Mater Res A. 2006 Sep 1;78(3):473-80. doi: 10.1002/jbm.a.30824.
There is currently considerable interest in the wear debris and osteolytic potential of different types of bearings used in total joint replacements. The biological activity of the wear debris is dependent on the size and volume of the particles produced. Wear volume also plays an important role in the functional biological activity of a joint replacement. In vitro studies have shown that crosslinking of ultra high molecular weight polyethylene (UHMWPE) acetabular cups and tibial trays produces a reduction in wear volume, and crosslinking has now been introduced clinically for both types of prostheses. Previous studies have identified both micron and submicron-sized polyethylene wear particles. The aim of this study was to characterize the wear and wear particles generated from moderately crosslinked GUR 1,020 GVF UHMWPE acetabular cups and tibial trays in hip and knee joint wear simulators down to 10 nanometers in size. The wear rates of the two prosthesis types were very similar at 25.6 +/- 5.3 mm(3) per million cycles for the hip prostheses and 22.75 +/- 5.95 mm(3) per million cycles for the knee prostheses. Nanometer-sized wear particles were isolated and characterized from both hip and knee simulator lubricants for the first time. Significantly higher numbers (p < 0.05) of particles in the nanometer (<0.1 microm) size range were produced by the hip prostheses compared to the knee prostheses. The knee prostheses produced larger particles, with the mode of particle size in the 0.1-1.0 microm size range, compared to <0.1 microm size range for the hip prostheses. In addition, the knee prostheses produced a greater volumetric concentration of wear particles in the 1.0-10 microm size range, and consequently lower specific biological activity and functional biological activity indices. These results indicated that the knee prostheses had a lower osteolytic potential compared to the hip prostheses.
目前，人们对全关节置换中使用的不同类型轴承的磨损碎屑及骨溶解潜能有着浓厚兴趣。磨损碎屑的生物活性取决于所产生颗粒的大小和体积。磨损量在关节置换的功能生物活性中也起着重要作用。体外研究表明，超高分子量聚乙烯（UHMWPE）髋臼杯和胫骨托的交联可减少磨损量，目前交联已在临床上应用于这两种假体。先前的研究已识别出微米级和亚微米级的聚乙烯磨损颗粒。本研究的目的是在髋关节和膝关节磨损模拟器中，对适度交联的GUR 1020 GVF UHMWPE髋臼杯和胫骨托产生的磨损及磨损颗粒进行表征，直至尺寸达到10纳米。两种假体类型的磨损率非常相似，髋关节假体为每百万次循环25.6±5.3立方毫米，膝关节假体为每百万次循环22.75±5.95立方毫米。首次从髋关节和膝关节模拟器润滑剂中分离并表征了纳米级磨损颗粒。与膝关节假体相比，髋关节假体产生的纳米级（<0.1微米）尺寸范围内的颗粒数量显著更多（p<0.05）。膝关节假体产生的颗粒更大，颗粒尺寸模式在0.1 - 1.0微米尺寸范围内，而髋关节假体的颗粒尺寸模式在<0.1微米尺寸范围内。此外，膝关节假体在1.0 - 10微米尺寸范围内产生的磨损颗粒体积浓度更高，因此其比生物活性和功能生物活性指数更低。这些结果表明，与髋关节假体相比，膝关节假体的骨溶解潜能更低。
