Mechanical and System Technology Laboratories, Industrial Technology Research Institute, Taichung, Taiwan, ROC.
Med Biol Eng Comput. 2012 Mar;50(3):253-60. doi: 10.1007/s11517-011-0852-x. Epub 2011 Dec 22.
This study investigated the wear phenomena of chamfered acetabular cup liners. The liners have three parameters at the lengthened rim: the length of the elongation, the depth of the cup and the chamfer angle. Using published wear volume equations for cylindrically elongated liners, this study analysed the volume of the chamfer to obtain the exact theoretical wear volume of the chamfered liner. The criteria described in our previous paper were used to verify the accuracy of the proposed methodology. The results showed that a shallow cup depth (<2 mm) and a chamfer angle of about 30° could significantly reduce the wear volume arising from the elongation. When the chamfer angle was increased further, this effect became progressively less significant. The results suggest that a chamfer angle up to about 30° is appropriate, but the angle should not be larger than required to obtain the minimum femoral range of motion (ROM). The results of this study can also be integrated with the analysis of the kinetics and kinematics of liners. A compromise design incorporating a lower wear volume, sufficient ROM and a lower contact stress should be possible.
本研究探讨了倒角髋臼杯衬垫的磨损现象。衬垫在加长边缘处有三个参数：伸长长度、杯深和倒角角度。利用已发表的用于圆柱形加长衬垫的磨损体积方程，本研究分析了倒角体积，以获得倒角衬垫的确切理论磨损体积。本研究使用了我们之前论文中描述的标准来验证所提出方法的准确性。结果表明，较浅的杯深（<2 毫米）和约 30°的倒角角度可以显著降低由于伸长引起的磨损体积。当进一步增加倒角角度时，这种效果变得不那么显著。结果表明，约 30°的倒角角度是合适的，但角度不应大于获得最小股骨活动范围（ROM）所需的角度。本研究的结果还可以与衬垫的动力学和运动学分析相结合。可以设计出一种折衷方案，将较低的磨损体积、足够的 ROM 和较低的接触应力结合在一起。
