Mueller-Rath Ralf, Kleffner Bernhard, Andereya Stefan, Mumme Torsten, Wirtz Dieter Christian
Department of Orthopaedic Surgery, RWTH Aachen University Hospital, Aachen, Germany.
Biomed Tech (Berl). 2007 Aug;52(4):295-300. doi: 10.1515/BMT.2007.050.
Wear of ultra-high-molecular-weight polyethylene (UHM-WPE) inlays is associated with aseptic loosening in total knee replacement (TKR). The aim of this study was to investigate the in vitro performance of a TKR system that combines several measures to decrease UHMWPE wear. Tests were carried out on a BPK-S Integration system (R&D, P. Brehm Chirurgie-Mechanik, Weisendorf, Germany) according to ISO 14,243-1 in a knee joint simulator. Calf serum with a high protein concentration of 30 g/l was chosen as the test lubricant. PE wear was measured gravimetrically. Particle analysis was performed by scanning electron microscopy, with measurement of particle size and shape. Low mean wear rates of 1.20 mg per million cycles were found for the fixed bearing type and 2.47 mg per million cycles for the rotating-platform bearing design. Anteroposterior deflection was low. The contact areas for both types of bearings were large and showed a constant pattern throughout the test. Backside wear was obvious on rotating platforms. Particle analysis revealed equally sized and round-shaped particles in both types of bearings (fixed, 0.35 microm; mobile, 0.32 microm). In conclusion, the combination of design features and surface modifications of the BPK-S integration TKR system leads to low gravimetric UHMWPE wear.
全膝关节置换术（TKR）中，超高分子量聚乙烯（UHM-WPE）内衬的磨损与无菌性松动相关。本研究旨在调查一种采用多种措施减少UHMWPE磨损的TKR系统的体外性能。在膝关节模拟器中，根据ISO 14,243-1标准，在BPK-S集成系统（德国魏森多夫P. Brehm Chirurgie-Mechanik研发公司）上进行测试。选择蛋白质浓度为30 g/l的小牛血清作为测试润滑剂。通过重量法测量聚乙烯磨损。通过扫描电子显微镜进行颗粒分析，并测量颗粒大小和形状。固定轴承类型的平均磨损率较低，为每百万次循环1.20 mg，旋转平台轴承设计的平均磨损率为每百万次循环2.47 mg。前后向偏斜较小。两种类型轴承的接触面积都很大，并且在整个测试过程中呈现出恒定的模式。旋转平台上的背面磨损明显。颗粒分析显示，两种类型的轴承（固定型，0.35微米；活动型，0.32微米）中都有大小相同且呈圆形的颗粒。总之，BPK-S集成TKR系统的设计特点和表面改性相结合，导致UHMWPE重量磨损较低。
