title: Noncemented, porous ingrowth knee prosthesis: the 3- to 8-year results.
abstract: OBJECTIVE
  To determine the principal long-term problems encountered in noncemented total knee replacement.
  
  
  METHODS
  A cohort of 252 consecutive cases of total knee replacement with no exclusions. Follow-up ranged from 3 to 8 years.
  
  
  METHODS
  A university-affiliated institution specializing in orthopedic surgery.
  
  
  METHODS
  All 252 patients had arthritis of the knee, mainly osteoarthritis. All agreed preoperatively to prolonged postoperative follow-up.
  
  
  METHODS
  Noncemented total knee replacement with the Tricon M prosthesis, which has a metal-backed patella.
  
  
  METHODS
  The Hospital for Special Surgery rating system for clinical results and the radiologic results, including reasons for revision surgery.
  
  
  RESULTS
  Thirty-five prostheses were revised: 11 prostheses because of patellar wear only; in 13 prostheses the tibial component (mainly a 6-mm unit) and patella were revised because of wear; 6 prostheses were revised for sepsis, 4 for reflex sympathetic dystrophy and 1 only for sinkage of the tibial component. Of the remaining 217 prostheses, 88% scored good or excellent, 6% fair and 6% poor.
  
  
  CONCLUSIONS
  The single most common cause of failure was polyethylene wear. This was associated with the metal backing of the patella and the use of thin, polyethylene tibial components.
authors.affiliation: Orthopaedic & Arthritic Hospital, University of Toronto, Ont.
authors.forename: H U
authors.initials: HU
authors.lastname: Cameron
authors.forename: Y B
authors.initials: YB
authors.lastname: Jung
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007720:Knee Prosthesis / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D016348:Osseointegration; D010003:Osteoarthritis / Q000601:surgery; D010027:Osteotomy; D010329:Patella / Q000473:pathology / Q000601:surgery; D011474:Prosthesis Design / Q000009:adverse effects; D011475:Prosthesis Failure; D016459:Prosthesis-Related Infections / Q000601:surgery; D012086:Reoperation; D013499:Surface Properties; D013977:Tibia / Q000473:pathology / Q000601:surgery; D016896:Treatment Outcome; D016474:Weight-Bearing