Review Question - QID 866

Ultra high molecular weight polyethylene (UHMWPE) is a semicrystalline polymer that has been used for over four decades as a bearing surface in total joint replacements. The mechanical properties and wear properties of UHMWPE are of interest with respect to the in vivo performance of UHMWPE joint replacement components. The mechanical properties of the polymer are dependent on both its crystalline and amorphous phases. Altering either phase (i.e., changing overall crystallinity, crystalline morphology, or crosslinking the amorphous phase) can affect the mechanical behavior of the material.

Per the referenced article by Gencur et al, crosslinking improved wear resistance, but also was found to decrease the ability of UHMWPE to resist crack inception and propagation under cyclic loading. The findings also suggested that annealing as a post-irradiation treatment may be somewhat less detrimental to fracture crack propogation resistance of UHMWPE than remelting. Answers 1 through 4 are inversely false statements.