title: Knee bearing technology: where is technology taking us?
abstract: A novel sequentially irradiated and annealed bearing material (X3), characterized for use in knee arthroplasty, has been developed. Attention was directed to mechanical strength properties, oxidation resistance, and the ability to reduce wear. Material properties such as ultimate tensile and yield strength were unaffected by the sequential cross-linking process. Elongation was reduced relative to GUR 1020 conventional polyethylene, but equivalent to that of direct compression molded 1900 material. In knee simulator testing for normal gait and stair climbing, measured wear rates for X3 polyethylene were reduced by 79% and 77% when compared to the same knee design using conventional polyethylene. Mechanical properties and wear characteristics of the X3 polyethylene were unaffected before and after exposure to accelerated aging; properties of conventional polyethylene were adversely impacted.
authors.affiliation: Stryker Orthopaedics, Mahwah, New Jersey 07430, USA.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Kester
authors.forename: Lizeth
authors.initials: L
authors.lastname: Herrera
authors.forename: Aiguo
authors.initials: A
authors.lastname: Wang
authors.forename: Aaron
authors.initials: A
authors.lastname: Essner
mesh_terms: D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation* / Q000379:methods; D001696:Biomechanical Phenomena; D020811:Biomedical Technology / Q000639:trends*; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology / Q000601:surgery; D008422:Materials Testing; D011095:Polyethylenes; D013718:Tensile Strength
chemical_list: D011095:Polyethylenes