title: Risk of cancer with metal-on-metal hip replacements: population based study.
abstract: OBJECTIVE
  To assess the risk of cancer associated with modern primary metal-on-metal hip replacements.
  
  
  METHODS
  Population based study.
  
  
  METHODS
  Nationwide retrospective comparative register.
  
  
  METHODS
  10,728 patients who underwent metal-on-metal total hip arthroplasty and 18,235 patients who underwent conventional metal-on-polyethylene, ceramic-on-polyethylene, and ceramic-on-ceramic total hip arthroplasty (the non-metal-on-metal cohort) in the Finnish Arthroplasty Register 2001-10. Data on cancer cases up to 2010 for these cohorts were extracted from the Finnish Cancer Registry.
  
  
  METHODS
  The relative risk of cancer was expressed as the ratio of observed to expected number of cases from the Finnish population--that is, the standardised incidence ratio. The relative risk of cancer in the metal-on-metal cohort compared with the non-metal-on-metal cohort was estimated with analyses of these ratios and Poisson regression.
  
  
  RESULTS
  The overall risk of cancer in patients with metal-on-metal hip implants was similar to that in the Finnish population (378 observed v 400 expected, standardised incidence ratio 0.95, 95% confidence interval 0.85 to 1.04). The overall risk of cancer in patients with metal-on-metal hip implants was also no higher than in patients who had received non-metal-on-metal hip implants (relative risk 0.92, 0.81 to 1.05).
  
  
  CONCLUSIONS
  Metal-on-metal hip replacements are not associated with an increased overall risk of cancer during a mean follow-up of four years.
authors: Department of Orthopaedics and Traumatology, Surgical Hospital, Turku University Hospital, FI-20701 Turku, Finland. keijo.makela@fimnet.fi
authors: Keijo T
authors: KT
authors: Mäkelä
authors: Tuomo
authors: T
authors: Visuri
authors: Pekka
authors: P
authors: Pulkkinen
authors: Antti
authors: A
authors: Eskelinen
authors: Ville
authors: V
authors: Remes
authors: Petri
authors: P
authors: Virolainen
authors: Mika
authors: M
authors: Junnila
authors: Eero
authors: E
authors: Pukkala
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects / Q000706:statistics & numerical data*; D002648:Child; D004812:Epidemiologic Methods; D005260:Female; D005387:Finland / Q000453:epidemiology; D015386:Hazardous Substances / Q000009:adverse effects*; D006622:Hip Prosthesis / Q000009:adverse effects / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008670:Metals / Q000009:adverse effects*; D008875:Middle Aged; D009369:Neoplasms / Q000453:epidemiology*; D011474:Prosthesis Design; D055815:Young Adult
chemical_list: D015386:Hazardous Substances; D008670:Metals