title: Radiostereometric analysis comparison of wear of highly cross-linked polyethylene against 36- vs 28-mm femoral heads.
abstract: This study used radiostereometric analysis (RSA) to compare the femoral head penetration of 28- vs 36-mm-diameter femoral heads into highly cross-linked polyethylene in 2 groups of total hip arthroplasty patients. Thirty patients were enrolled in this RSA study using highly cross-linked polyethylene (Longevity, Zimmer Inc, Warsaw, Idaho) against either 28- or 36-mm-diameter cobalt chrome femoral heads. At 3-year follow-up, there was no significant difference in the total average femoral head penetration, including both creep and wear, using 3 methods of RSA measurement between the 2 groups. Importantly, after bedding-in, there was no further significant increase in the amount of femoral head penetration (ie, wear) with either head size between years 1 and 3. There were no radiographic signs of lysis or radiolucencies at a minimum 3-year follow-up.
authors.affiliation: Orthopaedic Biomechanics and Biomaterials Laboratory, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA.
authors.forename: Charles R
authors.initials: CR
authors.lastname: Bragdon
authors.forename: Meridith E
authors.initials: ME
authors.lastname: Greene
authors.forename: Andrew A
authors.initials: AA
authors.lastname: Freiberg
authors.forename: William H
authors.initials: WH
authors.lastname: Harris
authors.forename: Henrik
authors.initials: H
authors.lastname: Malchau
mesh_terms: D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation*; D002858:Chromium Alloys; D006621:Hip Joint / Q000000981:diagnostic imaging; D006622:Hip Prosthesis; D006801:Humans; D011095:Polyethylenes; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011859:Radiography