Obesity not a contraindication to knee replacement

NEW YORK (Reuters Health) - Obese individuals with arthritic knees should not be denied knee replacement surgery, researchers conclude, based on a new study showing that obese patients benefit from the surgery almost as much as their normal-weight peers. Roughly 55,000 knee replacements are performed every year in England to relieve the pain and disability of knee arthritis, according to the British research team that conducted the study. But in some parts of the country the surgery is offered only to people who are not obese, on the grounds that obesity is itself a risk factor for knee arthritis. Dr. Cyrus Cooper, at the University of Southampton, and associates monitored the progress of 325 patients for around six years after they had had knee replacement surgery. Their progress was compared with that of 363 "control" patients seen in general medical practices, matched for age and sex, who had not had knee replacements. At the outset, physical function was markedly worse in the knee replacement patient group than in the control group. However, at follow-up, physical function had improved in the knee replacement patients, while that of controls had worsened. When the researchers restricted their analysis to participants who were obese, the improvements with knee surgery persisted. In obese patients, physical function increased in surgery patients and deteriorated in controls. "The long term improvement in physical function that we observed in patients who have undergone (knee replacement surgery) is striking when set against the decline that occurred in (the control group)," Cooper and colleagues say. "These benefits extend to patients who are obese." "There seems no justification for withholding (knee replacement surgery) from patients who are obese," they conclude.