title: Steady-state penetration rates of electron beam-irradiated, highly cross-linked polyethylene at an average 45-month follow-up.
abstract: Steady-state penetration rates were determined on 53 total hip arthroplasties with a minimum 3-year follow-up using electron beam highly cross-linked melted polyethylene by determining the femoral head penetration occurring after the first year in vivo. These data were compared with that of a matched control group. The average steady-state penetration rate of the control group was 144 +/- 191 mum/y, significantly higher than that of the highly cross-linked polyethylene group, 25 +/- 99 microm/y (P = .0001). Linear regression analysis indicated that the magnitude of femoral head penetration did not increase with time in the cross-linked groups. Also, no significant difference existed between the steady-state wear rates of the highly cross-linked groups with two head sizes (28 vs 32 mm, P = .39).
authors.affiliation: Orthopaedic Biomechanics and Biomaterials Laboratory and the Adult Reconstructive Unit of the Department of Orthopaedic Surgery of Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
authors.forename: Charles R
authors.initials: CR
authors.lastname: Bragdon
authors.forename: Susan
authors.initials: S
authors.lastname: Barrett
authors.forename: John M
authors.initials: JM
authors.lastname: Martell
authors.forename: Meridith E
authors.initials: ME
authors.lastname: Greene
authors.forename: Henrik
authors.initials: H
authors.lastname: Malchau
authors.forename: William H
authors.initials: WH
authors.lastname: Harris
mesh_terms: D019644:Arthroplasty, Replacement, Hip; D004583:Electrons; D005500:Follow-Up Studies; D006622:Hip Prosthesis; D006801:Humans; D020959:Polyethylene / Q000737:chemistry / Q000528:radiation effects*; D011475:Prosthesis Failure; D012044:Regression Analysis; D013997:Time Factors
chemical_list: D020959:Polyethylene