title: Posterior Stabilized Polyethylene Inserts in Total Knee Arthroplasty: A Retrieval Study Comparing Conventional to High-Flexion Designs.
abstract: BACKGROUND
  High-flex (HF) total knee arthroplasties are modified posterior-stabilized (PS) implants designed to accommodate greater flexion.
  
  
  METHODS
  We examined differences between HF and PS retrieved tibial inserts with regard to polyethylene surface damage. Twenty HF inserts from each of 3 manufacturers were matched using patient demographics with 20 PS inserts from the same manufacturers. Ranges of motion between matched patients were not different.
  
  
  RESULTS
  Based on subjective damage scores, no differences were detected between HF and PS groups. Differences were found, however, among manufacturers, consistent with design approaches taken for PS and HF implants.
  
  
  CONCLUSIONS
  In our series, high flexion did not influence damage, although this was likely influenced by the fact that few HF patients in our study had larger range of motions than their PS counterparts.
authors.affiliation: Hospital for Special Surgery, New York, New York.
authors.forename: Erik A
authors.initials: EA
authors.lastname: Schnaser
authors.affiliation: Hospital for Special Surgery, New York, New York.
authors.forename: Marcella E
authors.initials: ME
authors.lastname: Elpers
authors.affiliation: Hospital for Special Surgery, New York, New York.
authors.forename: Chelsea N
authors.initials: CN
authors.lastname: Koch
authors.affiliation: Hospital for Special Surgery, New York, New York.
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Haas
authors.affiliation: Hospital for Special Surgery, New York, New York.
authors.forename: Geoffrey H
authors.initials: GH
authors.lastname: Westrich
authors.affiliation: Hospital for Special Surgery, New York, New York.
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Wright
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation*; D005260:Female; D006801:Humans; D007720:Knee Prosthesis / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D020959:Polyethylene; D011474:Prosthesis Design; D016059:Range of Motion, Articular; D013499:Surface Properties; D013977:Tibia / Q000601:surgery; D016896:Treatment Outcome
chemical_list: D020959:Polyethylene
keywords: high flexion; knee arthroplasty; polyethylene damage; posterior stabilized; retrieval analysis