title: Oxinium modular femoral heads do not reduce polyethylene wear in cemented total hip arthroplasty at five years: a randomised trial of 120 hips using radiostereometric analysis.
abstract: We report the five-year outcome of a randomised controlled trial which used radiostereometric analysis (RSA) to assess the influence of surface oxidised zirconium (OxZr, Oxinium) on polyethylene wear in vivo. A total of 120 patients, 85 women and 35 men with a mean age of 70 years (59 to 80) who were scheduled for primary cemented total hip arthroplasty were randomly allocated to four study groups. Patients were blinded to their group assignment and received either a conventional polyethylene (CPE) or a highly cross-linked (HXL) acetabular component of identical design. On the femoral side patients received a 28 mm head made of either cobalt-chromium (CoCr) or OxZr. The proximal head penetration (wear) was measured with repeated RSA examinations over five years. Clinical outcome was measured using the Harris hip score. There was no difference in polyethylene wear between the two head materials when used with either of the two types of acetabular component (p = 0.3 to 0.6). When comparing the two types of polyethylene there was a significant difference in favour of HXLPE, regardless of the head material used (p < 0.001). In conclusion, we found no advantage of OxZr over CoCr in terms of polyethylene wear after five years of follow-up. Our findings do not support laboratory results which have shown a reduced rate of wear with OxZr. They do however add to the evidence on the better resistance to wear of HXLPE over CPE.
authors.affiliation: Haukeland University Hospital, Bergen, Norway.
authors.forename: B A
authors.initials: BA
authors.lastname: Jonsson
authors.affiliation: Haukeland University Hospital, Bergen, Norway.
authors.forename: T
authors.initials: T
authors.lastname: Kadar
authors.affiliation: Haukeland University Hospital, Bergen, Norway.
authors.forename: L I
authors.initials: LI
authors.lastname: Havelin
authors.affiliation: Trondheim University Hospital, Trondheim, Norway.
authors.forename: K
authors.initials: K
authors.lastname: Haugan
authors.affiliation: Haukeland University Hospital, Bergen, Norway.
authors.forename: B
authors.initials: B
authors.lastname: Espehaug
authors.affiliation: Haukeland University Hospital, Bergen, Norway.
authors.forename: K
authors.initials: K
authors.lastname: Indrekvam
authors.affiliation: Haukeland University Hospital, Bergen, Norway.
authors.forename: O
authors.initials: O
authors.lastname: Furnes
authors.affiliation: Haukeland University Hospital, Bergen, Norway.
authors.forename: G
authors.initials: G
authors.lastname: Hallan
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation* / Q000379:methods; D002484:Cementation; D005260:Female; D005270:Femur Head / Q000601:surgery*; D005500:Follow-Up Studies; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000601:surgery; D011446:Prospective Studies; D011474:Prosthesis Design; D011475:Prosthesis Failure; D059869:Radiostereometric Analysis / Q000379:methods; D016896:Treatment Outcome; D015040:Zirconium
chemical_list: D015040:Zirconium; C028541:zirconium oxide
keywords: Bearing materials; Cemented Total Hip Arthroplasty; Highly Cross-Linked Polyethylene; Oxidised zirconium