Tests and Analysis
- We simultaneously tested a total of 100 pin-on-disk couples (n = 10 per bearing couple) consisting of three traditional metal-on-UHMWPE and seven polymer-on-polymer bearings for 2 million cycles under physiologically relevant conditions and in accordance with ASTM F732.
- Using analysis of variance, we analyzed the effect of bearing surface topography and cross-shear on wear rate. The changes in surface topography were evaluated using optical microscopy. Sample size was sufficient to provide 80% power to detect a difference of 1.4 mm3/MC in average wear rates of bearing couples.
Pin-on-Disk Wear Testing of Biomaterials Used for Total Joint Replacements
Pin-on-Disk Wear Testing of Biomaterials Used for Total Joint Replacements
Our in vitro pin-on-disk data suggest that all-polymer bearings, especially PEEK-on-HXLPE bearing couples, may represent a viable alternative to traditional bearings with respect to their wear performance. Our results warrant further testing of all-polymer bearing couples in physiologically relevant joint simulator tests.
CLINICAL RELEVANCE: The in vitro pin-on-disk wear resistance of all-polymer bearings incorporating PEEK-on-HXLPE warrants further investigation using joint simulator testing for their validation as useful, metal-free alternatives to traditional CoCr-on-HXLPE bearings for use in orthopaedic applications.
