The impact of morbid obesity on patient outcomes after total knee arthroplasty

J Arthroplasty. 2008 Sep;23(6):795-800. doi: 10.1016/j.arth.2007.08.005. Epub 2008 Mar 4.


Five hundred fifty patients who underwent primary total knee arthroplasty between 1987 and 2004 with a primary diagnosis of osteoarthritis and 1-year outcome data (Western Ontario and McMaster Osteoarthritis Index [WOMAC]) were evaluated. Patients were stratified into body mass index categories based on the World Health Organization classification of obesity. Patients were dichotomized into a class III morbidly obese group and a non-morbidly obese group. Independent t test and multivariable linear regression were used to determine if a difference existed in the 1-year WOMAC outcome between morbidly obese patients and all other patients. Although 1-year outcomes were worse for morbidly obese patients (P < .05), they showed greater improvement in function compared with non-morbidly obese patients. Morbid obesity does not affect 1-year outcomes in patients who have had a total knee arthroplasty.

MeSH terms

  • Aged
  • Arthroplasty, Replacement, Knee*
  • Female
  • Humans
  • Linear Models
  • Male
  • Middle Aged
  • Obesity, Morbid / physiopathology*
  • Obesity, Morbid / psychology*
  • Osteoarthritis, Knee / physiopathology
  • Osteoarthritis, Knee / psychology
  • Osteoarthritis, Knee / surgery*
  • Outcome Assessment, Health Care*
  • Prospective Studies
  • Retrospective Studies
  • Treatment Outcome