Introduction: Obesity is a risk factor to develope knee OA. Patients who are obese often consider their disabling joint disease as a cause for their increased weight. The purpose of this study is to evaluate the changes of weigth and BMI in obese patients after TKA

Methods: 102 obese patients who underwent TKA between January 2002 and December 2003 were evaluated. They were followed for a mean duration of 35 months. Data about age, height, weight, BMI, hypertension, diabetes, NSAIDs and crutches were collected preoperative and at the end of follow-up. Statystical analysis was done using SPSSv11.5.

Results: Mean age was 69.8 y.o.. The average height was 157 cm. 24 were men and 78 women. Mean preoperative weight was 86.7 Kgs and at the end of follow-up was 87.3. BMI rose from 35.1 to 35.3. 90% recognized a better quality of life. 12.2% have a better control of their hypertension.30% needs NSAIDs and 4% uses crutches.

Conclusions: Obesity leads to an important number of Total Joint Replacement, specially TKA. Apparently it haven’t a worse outcome. Patients doesn’t loose weight after TKA, someones gain it. Knee OA can’t be considered as a cause of overweight.Obesity should be treated as an independent disease.