title: Mechanical properties, oxidation, and clinical performance of retrieved highly cross-linked Crossfire liners after intermediate-term implantation.
abstract: Sixty Crossfire (Stryker Orthopaedics, Mahwah, NJ) liners were consecutively revised after an average of 2.9 years (range, 0.01-8.0 years) for reasons unrelated to wear or mechanical performance of the polyethylene. Femoral head penetration was measured directly from 42 retrievals implanted for more than 1 year. Penetration rate results (0.04 mm/y, on average; range, 0.00-0.13 mm/y) confirmed decreasing wear rates with longer in vivo times. Overall, we observed oxidation levels at the bearing surface of the 60 liners (0.5, on average; range, 0.1-1.7) comparable to those of nonimplanted liners (0.5, on average; range, 0.3-1.1) and preservation of mechanical properties. We also measured elevated oxidation of the rim (3.4, on average; range, 0.2-8.8) that was correlated with implantation time. Rim surface damage, however, was observed in only 3 (5%) of 60 cases. Retrieval analysis of the 3 rim-damaged liners did not reveal an association between surface damage and the reasons for revision.
authors.affiliation: Implant Research Center, School of Biomedical Engineering, Science, and Health, Systems, Drexel University, Philadelphia, PA 19104, USA.
authors.forename: Steven M
authors.initials: SM
authors.lastname: Kurtz
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Austin
authors.forename: Khalid
authors.initials: K
authors.lastname: Azzam
authors.forename: Peter F
authors.initials: PF
authors.lastname: Sharkey
authors.forename: Daniel W
authors.initials: DW
authors.lastname: MacDonald
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Medel
authors.forename: William J
authors.initials: WJ
authors.lastname: Hozack
mesh_terms: D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation*; D001672:Biocompatible Materials; D001696:Biomechanical Phenomena; D020878:Device Removal; D019544:Equipment Failure Analysis; D005260:Female; D006622:Hip Prosthesis; D006801:Humans; D008875:Middle Aged; D018384:Oxidative Stress; D020959:Polyethylene; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012086:Reoperation
chemical_list: D001672:Biocompatible Materials; D020959:Polyethylene