The cause of osteoarthritis is not known.
Joint pain is the most common complaint in patients who suffer from osteoarthritis.
For the past several years, there has been growing interest in two dietary supplements, glucosamine and chondroitin sulfate, which are known components of cartilage. Because patients with osteoarthritis have abnormal cartilage, benefit from ingestion of these agents has seemed an attractive hypothesis might be beneficial. Although the use of these agents has been touted in the media as safe and effective, no carefully designed scientific study of sufficient size to determine the effectiveness of either glucosamine, chondroitin sulfate alone, or the combination of glucosamine and chondroitin has been performed. The National Institutes of Health has recently announced that a national multi-center trial will be conducted to determine the effectiveness of these agents. The study will be a sixteen-week trial comparing the effectiveness of glucosamine alone, chondroitin sulfate alone and the combination of glucosamine and chondroitin sulfate to placebo in relieving knee pain in patients with osteoarthritis.