title: Early death following primary total knee arthroplasty.
abstract: BACKGROUND
  Total knee arthroplasty carries major risks, including death. Conventional studies have compared the mortality rate following total knee arthroplasty with standardized mortality ratios or age and sex-matched populations. The purpose of the present study was to compare the mortality rate in a population of patients who were managed with total knee arthroplasty with that in patients who were awaiting surgery.
  
  
  METHODS
  All patients undergoing primary total knee arthroplasty from 2000 to 2007 at a single institution were recorded. In the same period, all patients who were added to the waiting list for total knee arthroplasty were recorded. The mortality rate and time to death were calculated, and death certificates were retrieved for those who died within thirty or ninety days after the index event.
  
  
  RESULTS
  Two thousand, six hundred and ninety-five patients undergoing primary total knee arthroplasty were used for the thirty-day mortality calculation, and 2527 were used for the ninety-day mortality calculation. These patients were compared with 5857 and 5689 patients who were added to the waiting list for the thirty-day and ninety-day mortality calculations, respectively. There was no difference between the populations in terms of age or sex (p > 0.05). The thirty-day mortality following surgery was significantly greater for the surgery group (0.371%; 95% confidence interval, 0.202% to 0.682%) than for the waiting list group (0.0683%; 95% confidence interval, 0.0266% to 0.1755%) (odds ratio, 5.45; 95% confidence interval, 1.81 to 16.43). The ninety-day mortality was also significantly greater for the surgery group (0.792%; 95% confidence interval, 0.513% to 1.219%) than for the waiting list group (0.387%; 95% confidence interval, 0.256% to 0.585%) (odds ratio, 2.05; 95% confidence interval, 1.13 to 3.74).
  
  
  CONCLUSIONS
  Primary total knee arthroplasty is associated with an increased risk of death at thirty and ninety days after the operation when compared with a population awaiting the same procedure. Increasing age was a risk factor for death following total knee arthroplasty.
authors: Department of Orthopaedic Surgery, University of Bristol, Bristol Implant Research Centre, Avon Orthopaedic Centre, Southmead Hospital, Westbury-on-Trym, Bristol BS10 5NB, United Kingdom. mdmcp@bristol.ac.uk
authors: Michael C
authors: MC
authors: Parry
authors: Alison J
authors: AJ
authors: Smith
authors: Ashley W
authors: AW
authors: Blom