Highly Cross-Linked Ultrahigh Molecular Weight Polyethylene With Improved Fatigue Resistance for Total Joint Arthroplasty: Recipient of the 2006 Hap Paul Award

Eliminating postirradiation melting and stabilizing the residual free radicals of radiation cross-linked ultrahigh molecular weight polyethylene (UHMWPE) with vitamin E resulted in improved fatigue crack propagation resistance without compromising wear resistance. We designed a cantilever postbending test to determine the bending fatigue resistance of α-tocopherol–doped, irradiated UHMWPE (α-TPE) in comparison to conventional UHMWPE. The bending fatigue behavior of α-TPE was comparable to conventional UHMWPE. Upon accelerated aging, the fatigue resistance of α-TPE was substantially better than that of conventional UHMWPE. α-TPE has shown improved wear and oxidation resistance, migration stability of vitamin E, and improved mechanical properties. The use of this material may be beneficial in total knee arthroplasty where its improved fatigue properties may be an advantage under high stresses.