title: Multicenter Study of Highly Cross-linked vs Conventional Polyethylene in Total Knee Arthroplasty.
abstract: BACKGROUND
  Despite substantial interest and use of highly cross-linked polyethylene (HXLPE) in total knee arthroplasty (TKA), outcomes remain largely unknown. The purpose of this study is to compare HXLPE and conventional polyethylene at 4- to 5-year follow-up.
  
  
  METHODS
  A prospective multicenter study of 307 posterior-stabilized TKAs (168 conventional and 139 HXLPE) was performed. Short-Form-6D, Short-Form 36, Knee Society Score, Lower Extremity Activity Score, health-related quality of life outcomes, and radiographs were collected preoperatively and at routine postoperative intervals.
  
  
  RESULTS
  Two hundred twenty-four patients obtained a minimum 4- to 5-year follow-up for analysis. There were no osteolysis or polyethylene failures in either group. Although both conventional and HXLPE poly groups showed significant improvements in all measures from preoperative baselines (P < .05), the XLPE group had slightly greater mean Knee Society Score function (P = .04), Lower Extremity Activity Score (P = .03), and Short-Form 36 Physical Composite Score (P = .03) scores and a greater improvement in Short-Form 6D health-related quality of life of 0.16 points (d = 1.02, 95% CI: 0.01-1.11) at latest follow-up.
  
  
  CONCLUSIONS
  The study findings support comparative safety and outcomes of HXLPE related to mechanical failure or osteolysis in the midterm. However, longer-term follow-up is warranted to assess whether wear and mechanical properties of HXLPE are maintained in vivo.
authors.affiliation: Department of Orthopaedic Surgery, Indiana University Health Physicians, Indiana University School of Medicine, Indianapolis, Indiana.
authors.forename: R Michael
authors.initials: RM
authors.lastname: Meneghini
authors.affiliation: Department of Orthopaedic Surgery, Indiana University Health Physicians, Indiana University School of Medicine, Indianapolis, Indiana.
authors.forename: Philip H
authors.initials: PH
authors.lastname: Ireland
authors.affiliation: Stryker Orthopaedics, Mahwah, New Jersey.
authors.forename: Manoshi
authors.initials: M
authors.lastname: Bhowmik-Stoker
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000601:surgery; D007720:Knee Prosthesis / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D020959:Polyethylene; D011446:Prospective Studies; D011474:Prosthesis Design; D011788:Quality of Life
chemical_list: D020959:Polyethylene
keywords: annealed polyethylene; clinical outcomes; highly-crosslinked polyethylene; mid-term; total knee arthroplasty; total knee replacement