title: Lower prosthesis-specific 10-year revision rate with crosslinked than with non-crosslinked polyethylene in primary total knee arthroplasty.
abstract: OBJECTIVE
  While highly crosslinked polyethylene has shown reduced in vivo wear and lower rates of revision for total hip arthroplasty, there have been few long-term studies on its use in total knee arthroplasty (TKA). We compared the rate of revision of non-crosslinked polyethylene to that of crosslinked polyethylene in patients who underwent TKA for osteoarthritis.
  
  
  METHODS
  We examined data from the Australian Orthopaedic Association National Joint Replacement Registry on 302,214 primary TKA procedures with non-crosslinked polyethylene and 83,890 procedures with crosslinked polyethylene, all of which were performed for osteoarthritis. The survivorship of the different polyethylenes was estimated using the Kaplan-Meier method and was compared using proportional hazard models.
  
  
  RESULTS
  The 10-year cumulative revision rate for non-crosslinked polyethylene was 5.8% (95% CI: 5.7-6.0) and for crosslinked polyethylene it was 3.5% (95% CI: 3.2-3.8) (> 6.5-year HR = 2.2 (1.5-3.1); p < 0.001). There was no effect of surgical volume or method of prosthesis fixation on outcome. There were 4 different TKA designs that had a minimum of 2,500 procedures in at least 1 of the polyethylene groups and a follow-up of ≥ 5 years. 2 of these, the NexGen and the Natural Knee II, had a lower rate of revision for crosslinked polyethylene. The Scorpio NRG/Series 7000 and the Triathlon Knee did not show a lower rate of revision for crosslinked polyethylene.
  
  
  CONCLUSIONS
  There is a lower rate of revision for crosslinked polyethylene in TKA, and this appears to be prosthesis-specific and when it occurs is most evident in patients < 65 years of age. The difference in revision rates was mainly due to revisions because of lysis and loosening.
authors.affiliation: a 1 Australian Orthopaedic Association National Joint Replacement Registry, Discipline of Public Health, University of Adelaide , Adelaide.|b 2 School of Population Health and Clinical Practice, University of Adelaide , Adelaide, SA, Australia.
authors.forename: Richard N
authors.initials: RN
authors.lastname: de Steiger
authors.affiliation: c 3 Harris Orthopaedic Laboratory, Massachusetts General Hospital , Boston, MA, USA.
authors.forename: Orhun
authors.initials: O
authors.lastname: Muratoglu
authors.affiliation: d 4 Data Management and Analysis Centre, University of Adelaide , Adelaide, SA, Australia.
authors.forename: Michelle
authors.initials: M
authors.lastname: Lorimer
authors.affiliation: d 4 Data Management and Analysis Centre, University of Adelaide , Adelaide, SA, Australia.
authors.forename: Alana R
authors.initials: AR
authors.lastname: Cuthbert
authors.affiliation: a 1 Australian Orthopaedic Association National Joint Replacement Registry, Discipline of Public Health, University of Adelaide , Adelaide.
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Graves
mesh_terms: D000367:Age Factors; D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects / Q000379:methods*; D001315:Australia / Q000453:epidemiology; D005260:Female; D006801:Humans; D007720:Knee Prosthesis / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000601:surgery; D020959:Polyethylene; D011475:Prosthesis Failure / Q000209:etiology*; D012042:Registries; D012086:Reoperation / Q000706:statistics & numerical data; D013997:Time Factors
chemical_list: D020959:Polyethylene