Affiliations: Physics Department, University of Messina, Salita Sperone 31, I‐98166 Messina, Italy | Industrial Chemistry and Material Engineering Department,University of Messina, Salita Sperone 31, I‐98166 Messina, Italy | Istituto Ortopedico del Mezzogiorno d'Italia, Ganzirri, Messina, Italy
Note: [] Corresponding author: Prof. Lorenzo Torrisi, Dipartimento di Fisica, Università di Messina, Salita Sperone, 31 (Casella postale 29), Sant'Agata di Messina, I‐98166 Messina, Italy. Tel.: +39 90 6765052; Fax: +39 90 395004; E‐mail: [email protected].
Abstract: The significant wear of the UHMWPE bearings of explanted knee prostheses is produced mainly by micrometric debris (“third‐body” wear) that diffuse toward the mobile metal–polymer interface. Here debris is crushed during the movement producing scratches in the metal and in the polymeric surfaces. Mechanical stress and the biological effects change the physical polymeric properties. In order to evaluate the area of UHMWE bearings submitted to high load stresses, in this work physical investigations are performed on the explanted knee prosthesis. Particularly, the roughness profile analysis (RPA) and the micro‐hardness measurements (MHM) resulted suitable for the localisation of the mechanical and biological wear area. In the stressed zone, surface treatments could be applied in order to improve the mechanical resistance of the polymeric material. Particularly, the ion implantation with heavy ions is proposed to enhance the polymeric wear resistance. The Scanning Electron Microscopy (SEM), Energy Dispersive X‐ray Spectrometry (EDX) and Infrared absorption spectroscopy (FTIR) techniques were also applied and results discussed.
