title: Influence of crosslinking on the wear performance of polyethylene within total ankle arthroplasty.
abstract: BACKGROUND
  Wear debris of polyethylene within joint replacement systems can result in clinical complications including osteolysis and component loosening. Highly crosslinked polyethylene (HXPE) was introduced to improve these outcomes, and has been shown to result in improved wear performance in several joint replacement systems. However, bearing couples within total ankle replacement (TAR) systems have historically used conventional polyethylene (CPE) articulating on metal. The extent to which HXPE would result in a reduction of polyethylene wear compared to CPE in the ankle has not been studied. The hypothesis motivating this study was that use of HXPE within TAR will result in significantly lower wear rate than CPE.
  
  
  METHODS
  HXPE and CPE inserts within a semiconstrained, bicondylar TAR system were manufactured for this study. Samples were subjected to 5.0 million cycles of wear on an in vitro wear simulator. Testing was performed within a physiological environment, using kinematic and kinetic loading profiles characteristic of walking gait. Samples were weighed at regular intervals to determine gravimetric mass loss, and the morphology of wear particles was analyzed.
  
  
  RESULTS
  The wear rates for CPE and HXPE samples were 7.4 ± 1.3 and 1.9 ± 0.3 mg/Mc (mean ± SD), respectively. HXPE samples exhibited a significant (P < .01) wear rate reduction of 74% when compared with the CPE. Debris morphology trends between HXPE and CPE were consistent with what has been observed in other joint systems.
  
  
  CONCLUSIONS
  Use of HXPE significantly reduces wear of TAR as compared to CPE, based on in vitro wear testing.
  
  
  CONCLUSIONS
  Highly crosslinked polyethylene may reduce clinical complications of total ankle replacement that are linked to polyethylene wear.
authors.affiliation: Zimmer, Inc, Warsaw, IN, USA jeff.bischoff@zimmer.com.
authors.forename: Jeffrey E
authors.initials: JE
authors.lastname: Bischoff
authors.affiliation: Zimmer, Inc, Warsaw, IN, USA.
authors.forename: J Craig
authors.initials: JC
authors.lastname: Fryman
authors.affiliation: Zimmer, Inc, Warsaw, IN, USA.
authors.forename: Jerry
authors.initials: J
authors.lastname: Parcell
authors.affiliation: Zimmer, Inc, Warsaw, IN, USA.
authors.forename: Diego A
authors.initials: DA
authors.lastname: Orozco Villaseñor
mesh_terms: D058737:Arthroplasty, Replacement, Ankle / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D019544:Equipment Failure Analysis / Q000379:methods; D006801:Humans; D007595:Joint Prosthesis; D008422:Materials Testing / Q000379:methods*; D011095:Polyethylenes; D011474:Prosthesis Design / Q000379:methods*; D011475:Prosthesis Failure; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D013314:Stress, Mechanical; D016474:Weight-Bearing
chemical_list: D011095:Polyethylenes; C111601:ultra-high molecular weight polyethylene
keywords: crosslinking; polyethylene; total ankle replacement; wear