title: Long-term mortality and causes of death among patients with a total knee prosthesis in primary osteoarthritis.
abstract: BACKGROUND
  Short and midterm mortality of patients with osteoarthritis (OA) who have undergone total knee arthroplasty (TKA) is generally lower than that of the general population. Due to an increasing number of young patients who undergo TKA the expected lifetime of these patients is increasing. The purpose of this study was to assess the causes of death and long-term mortality among Finnish TKA patients.
  
  
  METHODS
  Standardized mortality ratios (SMRs) for total and site specific causes of death were calculated for 9443 TKA patients operated on in 1980 to 1996 for OA and followed until 2012.
  
  
  RESULTS
  The mean follow-up time was 14 years (maximum 33 years). During follow-up, 77% of the patients had died. The all-cause SMR was 1.00. It was significantly lower than in the reference population (SMR 0.73) during the first 10 years after operation, but higher during the next 10 years (SMR 1.23), and even more after 20 years (SMR 1.95). The SMR for cardiovascular mortality was 1.03 and accounted for 52% of all deaths. Significant excess mortality was observed in diseases of the digestive tract (SMR 1.29). Deaths due to cardiovascular diseases, Alzheimer's disease and dementia comprised 68% of all deaths that took place 10 years or later after TKA.
  
  
  CONCLUSIONS
  The mortality of TKA patients with OA is significantly reduced during the first 10 postoperative years but exceeds the mortality of the general population after that. This trend should be taken into account when young patients undergo a TKA.
  
  
  METHODS
  Observational study, III.
authors.affiliation: Department of Public Health, University of Helsinki, P.O. Box 40, FI-00140, Finland. Electronic address: tuomo.visuri@helsinki.fi.
authors.forename: Tuomo
authors.initials: T
authors.lastname: Visuri
authors.affiliation: Department of Orthopedics and Traumatology, University of Turku, FI-20014, Finland.
authors.forename: Keijo
authors.initials: K
authors.lastname: Mäkelä
authors.affiliation: Department of Public Health, University of Helsinki, P.O. Box 40, FI-00140, Finland.
authors.forename: Pekka
authors.initials: P
authors.lastname: Pulkkinen
authors.affiliation: Finnish Cancer Registry, Institute for Statistical and Epidemiological Cancer Research, Unioninkatu 22, FI 00130 Helsinki, Finland.
authors.forename: Mia
authors.initials: M
authors.lastname: Artama
authors.affiliation: Finnish Cancer Registry, Institute for Statistical and Epidemiological Cancer Research, Unioninkatu 22, FI 00130 Helsinki, Finland; School of Health Sciences, University of Tampere, FI-33014, Finland.
authors.forename: Eero
authors.initials: E
authors.lastname: Pukkala
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000401:mortality*; D002423:Cause of Death / Q000639:trends; D005260:Female; D005387:Finland / Q000453:epidemiology; D005544:Forecasting; D006801:Humans; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000401:mortality / Q000601:surgery*; D011183:Postoperative Complications / Q000401:mortality*; D012042:Registries; D012189:Retrospective Studies; D015996:Survival Rate / Q000639:trends
keywords: Long term mortality; Primary osteoarthritis; Total knee arthroplasty