Hello, Glucosamine has attained great popularity as a nutritional supplement, primarily for osteoarthritis. The limited in vivo studies that have been done suggest that very little glucosamine taken orally actually gets into the joint. This raises the possibility of a placebo effect but does not rule out mechanisms of action at a level as yet unknown. Since the role of glucosamine is very controversial ,I would never rely on this product specially in the situation where the patient is a fit case of knee transplant. Had I been your doctor,I would have asked you to go for knee transplant as three months is a long time and a seemingly fit case for surgery can  be rendered unfit because of any unforeseen circumstances. Thanks