title: In vivo femoral head damage and its effect on polyethylene wear.
abstract: The purposes of this study were to determine the spectrum of femoral head damage in patients undergoing revision total hip arthroplasty and to determine the impact of that damage on polyethylene wear. One hundred eight consecutive modular metal femoral heads were retrieved at revision surgery. The mean roughness (Ra) value was 0.18 +/- 0.18 microm. The roughest femoral heads (mean Ra, 0.56 microm) were from retrievals correlated with mode 2 wear (recurrent dislocation and complete wear through of the polyethylene liner). Five million cycles of wear tests were performed using retrieved femoral heads against both new conventional and highly cross-linked polyethylene. The mean wear rate of conventional polyethylene was 15.9 +/- 4.3 mg and that of highly cross-linked polyethylene was 0.04 +/- 0.14 mg per 1 million cycles (P < .001). Highly cross-linked polyethylene was more resistant to wear than conventional polyethylene, even when mated against roughened femoral heads.
authors.affiliation: Department of Orthopaedic Surgery, Asahikawa Medical College, Midorigaoka, Asahikawa, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ito
authors.forename: Caitlin M
authors.initials: CM
authors.lastname: Maloney
authors.forename: Roy D
authors.initials: RD
authors.lastname: Crowninshield
authors.forename: John C
authors.initials: JC
authors.lastname: Clohisy
authors.forename: Douglas J
authors.initials: DJ
authors.lastname: McDonald
authors.forename: William J
authors.initials: WJ
authors.lastname: Maloney
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects* / Q000295:instrumentation*; D002858:Chromium Alloys; D020878:Device Removal; D019544:Equipment Failure Analysis; D005260:Female; D005270:Femur Head / Q000293:injuries*; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D010014:Osteolysis / Q000453:epidemiology / Q000209:etiology; D020959:Polyethylene; D011475:Prosthesis Failure; D012086:Reoperation; D012189:Retrospective Studies
chemical_list: D002858:Chromium Alloys; D020959:Polyethylene