Volume 1, Issue 1 (January 2004)

    Multiaxial Fatigue Behavior of Oxidized and Unoxidized UHMWPE During Cyclic Small Punch Testing at Body Temperature

    (Received 5 September 2002; accepted 11 June 2003)

    Published Online: 2004

    CODEN: JAIOAD

      Format Pages Price  
    PDF Version 19 $25   ADD TO CART


    Abstract

    We hypothesized that oxidation would influence the resistance to fatigue crack initiation and propagation of Ultra-High molecular weight polyethylene (UHMWPE). We subjected tibial insert surrogates (ram extruded GUR 1050) to accelerated aging protocols following ASTM F 2003-00 (14, 21 and 28 days). Subsurface disc specimens from the control and aged materials at each time period were subjected to cyclic small punch loading to failure (modification of ASTM F 2183-02). A significant decrease in fatigue loading was observed, relative to the un-aged controls, starting at three weeks of accelerated aging. Furthermore, SEM examination of the failed aged specimens revealed a network of multiple secondary initiation sites, which was also confirmed by observation with endoscopy, and microCT. Thus, in contrast to the unoxidized highly crosslinked conventional materials evaluated previously, the oxidized materials failed by the initiation and propagation of cracks from numerous initiation sites with the brittle appearance increasing with oxidation time. These results suggest that oxidized UHMWPE exhibits a different fatigue crack initiation and propagation behavior compared to unoxidized virgin, and crosslinked UHMWPE. Future studies will be needed to increase our understanding of the clinically acceptable fatigue properties for new tibial bearing materials, such as highly crosslinked UHMWPEs.


    Author Information:

    Villarraga, ML
    Managing Engineer and Principal EngineerResearch Associate Professors, Exponent, Inc.Implant Research Center, School of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, PA

    Edidin, AA
    Research Associate Professor, Implant Research Center, School of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, PA

    Herr, M
    Senior Engineer, Exponent, and Graduate Student, School of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, PA

    Kurtz, SM
    Managing Engineer and Principal EngineerResearch Associate Professors, Exponent, Inc.Implant Research Center, School of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, PA


    Stock #: JAI11218

    ISSN: 1546-962X

    DOI: 10.1520/JAI11218

    ASTM International is a member of CrossRef.

    Author
    Title Multiaxial Fatigue Behavior of Oxidized and Unoxidized UHMWPE During Cyclic Small Punch Testing at Body Temperature
    Symposium Crosslinked and Thermally Treated Ultra-High Molecular Weight Polyethylene for Joint Replacements, 2002-11-07
    Committee F04