title: 3-year follow-up of a long-term registry-based multicentre study on vitamin E diffused polyethylene in total hip replacement.
abstract: OBJECTIVE
  Preclinical studies of vitamin E diffused highly cross-linked polyethylene (E-XLPE) has shown enhanced mechanical properties with less wear. The purpose of our study was to document the early clinical outcome of E-XLPE to ensure, for the safety of patients, that there are no unforeseen early adverse events from using this new biomaterial.
  
  
  METHODS
  The enrolled patients (n = 977) have received either a porous titanium coated or porous plasma sprayed acetabular shell with either a E-XLPE liner or a medium cross-linked (AXL) liner. At each follow-up 5 patient-reported outcome measures (PROMs) were completed: Harris Hip Score, Case Mix Indicator, UCLA Activity Score, SF-36, and EQ-5D. Radiographs were measured for cup and stem position, as well as femoral head penetration into the liner (wear). Postoperative complications and revisions were collected.
  
  
  RESULTS
  At 3 years follow-up, there were 13 revisions due to: 4 periprosthetic fractures; 1 sepsis; 6 instabilities; and 2 implant mismatches at surgery. Wear of the hip implant, calculated by software analysis of pelvis x-rays, from the postoperative interval to 3 years showed a liner penetration rate of 0.027 mm/year for AXL and 0.005 mm/year for E-XLPE with no significant difference between the 2 (p = 0.24). Improvement was seen in all PROMs from the preoperative interval to 3 years after surgery (p&lt;0.0001).
  
  
  CONCLUSIONS
  Early follow-up of the E-XLPE and AXL liners show low penetration. PROMs indicate improvement after total hip arthroplasty in functionality and quality of life across the centers. We have not observed any early in vivo adverse effects from diffusing the liners with vitamin E.
  
  
  BACKGROUND
  ClinicalTrials.gov Identifier: NCT00545285.
authors.affiliation: Harris Orthopaedic Laboratory, Massachusetts General Hospital, Boston - USA.
authors.forename: Nanna H
authors.initials: NH
authors.lastname: Sillesen
authors.affiliation: Harris Orthopaedic Laboratory, Massachusetts General Hospital, Boston - USA.
authors.forename: Meridith E
authors.initials: ME
authors.lastname: Greene
authors.affiliation: Harris Orthopaedic Laboratory, Massachusetts General Hospital, Boston - USA.
authors.forename: Audrey K
authors.initials: AK
authors.lastname: Nebergall
authors.affiliation: Department of Orthopaedic Surgery, Stanford University Medical Center, Stanford - USA.
authors.forename: James I
authors.initials: JI
authors.lastname: Huddleston
authors.affiliation: Texas center for Joint Replacement, Plano, Texas - USA.
authors.forename: Roger
authors.initials: R
authors.lastname: Emerson
authors.affiliation: Department of Orthopaedics, Clinical Orthopedic Research Hvidovre, Copenhagen University Hospital Hvidovre, Hvidovre - Denmark.
authors.forename: Peter
authors.initials: P
authors.lastname: Gebuhr
authors.affiliation: Department of Orthopaedics, Clinical Orthopedic Research Hvidovre, Copenhagen University Hospital Hvidovre, Hvidovre - Denmark.
authors.forename: Anders
authors.initials: A
authors.lastname: Troelsen
authors.affiliation: Harris Orthopaedic Laboratory, Massachusetts General Hospital, Boston - USA.
authors.forename: Henrik
authors.initials: H
authors.lastname: Malchau
mesh_terms: D000328:Adult; D000368:Aged; D000975:Antioxidants / Q000008:administration & dosage*; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation*; D005260:Female; D005500:Follow-Up Studies; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000601:surgery*; D020959:Polyethylene; D011446:Prospective Studies; D011474:Prosthesis Design; D012042:Registries; D013997:Time Factors; D016896:Treatment Outcome; D014810:Vitamin E / Q000008:administration & dosage*
chemical_list: D000975:Antioxidants; D014810:Vitamin E; D020959:Polyethylene