Affecting more than nine per cent of people over 63, osteoarthritis is the most common joint disease. Prevalence rises with age, so health care costs are expected to increase as our population ages. Glucosamine is a health food supplement that is widely promoted for treating osteoarthritis pain. Claims have been made that glucosamine may repair cartilage damage and cure osteoarthritis. Glucosamine use has risen dramatically as a result, but there is limited scientific evidence supporting these claims. Dr. Jolanda Cibere is conducting a study with patients taking glucosamine for knee osteoarthritis. Patients are randomly assigned to continue taking glucosamine or to receive identical-looking placebo tablets. Jolanda will assess whether people whose pain was relieved with glucosamine experience a flare up of pain when treatment stops. This research will provide insights about the effectiveness of glucosamine as a treatment for osteoarthritis pain.