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B. Duscher, A. Laska, A. Örs Ünsal, V. Archodoulaki:
"Structural Modification of Conventional and Crosslinked PE-UHMW Acetabular Liners due to in vivo Time and Load";
Talk: FBPS '15 - 11th Symposium on Frontiers in Biomedical Polymers, Riva del Garda, Idataly; 2015-07-08 - 2015-07-11.

Due to its high toughness, durability and impact resistance, its notable abrasion resistance and chemical inertness ultrahigh molecular weight polyethylene (PE-UHMW) has been used for more than 4 decades as articulating material in total joint replacement. As a
semicrystalline polymer structural modifications are shown by physical aging in the crystalline phase with time and load or chain scission by oxidative degradation in the amorphous phase due to environmental factors. These morphological and molecular changes affect its mechanical properties, and thus can deteriorate in vivo performance. The evaluation of the retrieved acetabular liners is performed in view of in vivo time and material state (conventional or crosslinked). A depth profile over the cross-section of the liners is prepared and the oxidative degradation investigated by means of Fourier Transformed Infrared Spectroscopy (FTIR) and morphology characterized by differential scanning calorimetry (DSC) are determined. Correlations of chemical constitution and morphology with micro-hardness and indentation-modulus are found. By diffusion of biomolecules into the amorphous regions of the polymer changes of micro-mechanical properties are shown. In general, by crosslinking the initial state is changed to lower crystallinity, hardness and indentation-modulus, however, during in vivo lamellar thickness distribution is affected and oxidation occurs for both types of PE-UHMW.

PE-UHMW, acetabular liner, in vivo time, morphology