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Abstract

It is well known that osteolysis induced by polyethylene wear debris is the main cause of long-term failure of hip and knee prosthesis. We developed a treatment of medical-grade, ultra-high molecular-weight polyethylene (UHMWPE) in order to improve its tribologic properties and reduce its wear. Medical-grade UHMWPE was irradiated with a 200 kGy dose of radiation, thermally stabilized at a temperature below the melting point, then sterilized with ethylene oxide. The irradiation treatment was performed to crosslink the UHMWPE. The thermal stabilization treatment, contributing to the reaction between the free radicals generated by the irradiation process, was chosen to enhance crosslinking and to prevent the reformation of free radicals. The wear performance of this material was compared to UHMWPE, untreated or treated with different sterilization techniques, using gamma and beta irradiation. Insoluble crosslinked constituents were measured with an extraction method. Wear was evaluated using a flat-on-ring wear test machine. While small differences were found among the different sterilization processes, 200 kGy-irradiated UHMWPE followed by thermal treatment and sterilization with ethylene oxide had the least wear and the greatest amount of crosslinking.

Additional information

Authors: CHIESA R, Dipartimento di Chimica Fisica Applicata, Politecnico di Milano (IT);CIGADA A, Dipartimento di Chimica Fisica Applicata, Politecnico di Milano (IT);TANZI M C, Dipartimento di Bioingegneria, Politecnico di Milano (IT);MOSCATELLI M, Dipartimento di Bioingegneria, Politecnico di Milano (IT);ALFONSI S, SAMO SpA, Cadriano di Granarola Emilia, Bologna (IT);PARACCHINI L, Institute for Health and Consumer Protection, Joint Research Centre, Ispra (IT)
Bibliographic Reference: Article: Journal of Biomedical Material Research (2000) No. 50 pp. 381-387
Availability: Journal of Biomedical Material Research
Record Number: 200012157 / Last updated on: 2000-08-10
Category: PUBLICATION
Original language: en
Available languages: en