Institute of Production Engineering and Machine Tools (IFW), Gottfried Wilhelm Leibniz Universität Hannover, An der Universität 2, 30823 Garbsen, Germany.
Biomed Eng Online. 2013 Aug 29;12:84. doi: 10.1186/1475-925X-12-84.
Ceramic materials are used in a growing proportion of hip joint prostheses due to their wear resistance and biocompatibility properties. However, ceramics have not been applied successfully in total knee joint endoprostheses to date. One reason for this is that with strict surface quality requirements, there are significant challenges with regard to machining. High-toughness bioceramics can only be machined by grinding and polishing processes. The aim of this study was to develop an automated process chain for the manufacturing of an all-ceramic knee implant.
A five-axis machining process was developed for all-ceramic implant components. These components were used in an investigation of the influence of surface conformity on wear behavior under simplified knee joint motion.
The implant components showed considerably reduced wear compared to conventional material combinations. Contact area resulting from a variety of component surface shapes, with a variety of levels of surface conformity, greatly influenced wear rate.
It is possible to realize an all-ceramic knee endoprosthesis device, with a precise and affordable manufacturing process. The shape accuracy of the component surfaces, as specified by the design and achieved during the manufacturing process, has a substantial influence on the wear behavior of the prosthesis. This result, if corroborated by results with a greater sample size, is likely to influence the design parameters of such devices.
由于陶瓷材料具有耐磨和生物相容性等特性，在髋关节假体中越来越多地使用陶瓷材料。然而，到目前为止，陶瓷材料尚未成功应用于全膝关节假体。原因之一是，由于对表面质量要求严格，加工方面存在重大挑战。高韧性生物陶瓷只能通过磨削和抛光工艺进行加工。本研究的目的是开发用于制造全陶瓷膝关节植入物的自动化制造链。
为全陶瓷植入物组件开发了五轴加工工艺。这些组件用于研究在简化的膝关节运动下表面一致性对磨损行为的影响。
与传统材料组合相比，植入物组件的磨损大大减少。接触面积来自各种组件表面形状，表面一致性的各种水平，极大地影响了磨损率。
可以实现具有精确和经济实惠的制造工艺的全陶瓷膝关节假体装置。组件表面的形状精度由设计规定，并在制造过程中实现，对假体的磨损行为有重大影响。如果更大样本量的结果证实了这一结果，那么这一结果可能会影响此类设备的设计参数。
