title: Study of mechanical degradation of UHMWPE acetabular components due to clinical X-ray procedures.
abstract: The use of multi-component femoral implants to replace the femur head and re-establish bone motion has been widespread since the 70s. Frequently these implants have spherical metallic heads made of, for example, 316-L stainless steel or Cr-Co alloys, which allow rotational motion towards a polymeric component (UHMWPE). One of the major causes of implant rejection is the generation of UHMWPE debris on the surface between the implant head and the polymeric component. The gamma ray sterilization of implants and the periodical X-ray medical control could contribute to premature degradation of the polymeric surface, resulting in increased wear and shortened lifetime of the implant. In this work we study the degradation degree of the polymeric UHMWPE component as function of the X-ray dose. The elasto-plastic deformation and recovery were carried out by means of a nanohardness tester equipment and the polymer degradation was measured using a fast Fourier transform infra-red (FT-IR) equipment. The results show the compromise among the irradiation doses, the surface oxidation and the mechanical properties of the samples.
authors.affiliation: Gepsi--Centro de Pesquisa e Desenvolvimento Em Física--Tecnopuc, Pontifícia Universidade Católica do Rio Grande do Sul, P.O. Box 1429, 90619-900 Porto Alegre, RS, Brazil.
authors.forename: Letícia A
authors.initials: LA
authors.lastname: Vasconcellos
authors.forename: Eduardo
authors.initials: E
authors.lastname: Blando
authors.forename: André A
authors.initials: AA
authors.lastname: Souto
authors.forename: Marilia G
authors.initials: MG
authors.lastname: Oliveira
authors.forename: Gilséia F P
authors.initials: GF
authors.lastname: Woitchunas
authors.forename: Roberto
authors.initials: R
authors.lastname: Hübler
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry* / Q000528:radiation effects*; D019245:Compressive Strength / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D004548:Elasticity / Q000528:radiation effects; D006244:Hardness / Q000528:radiation effects; D008422:Materials Testing; D011095:Polyethylenes / Q000737:chemistry* / Q000528:radiation effects*; D011829:Radiation Dosage; D011859:Radiography; D013499:Surface Properties / Q000528:radiation effects; D014965:X-Rays
chemical_list: D001672:Biocompatible Materials; D011095:Polyethylenes; C111601:ultra-high molecular weight polyethylene