VIENNA — The use of oral glucosamine by patients with knee osteoarthritis results in a marked reduction in need for knee replacement surgery for at least 5 years after the drug is stopped, Karel Pavelka, M.D., reported at the annual European congress of rheumatology.
He presented new 5-year follow-up data from his previously reported double-blind placebo-controlled trial involving 202 patients with knee osteoarthritis randomized to oral glucosamine sulfate at 1,500 mg once daily or placebo for 3 years (Arch. Intern. Med. 2002;162:2113–23).
During the next 5 years after the 3-year trial ended and patients were back on standard conservative management, 11 of 67 patients formerly in the placebo arm underwent total knee replacement, as did 3 of 69 previously on glucosamine. This represents a 73% reduction in the risk of surgical knee replacement. The number of patients who needed to be treated with glucosamine instead of placebo to avoid one additional knee replacement was eight, noted Dr. Pavelka of Charles University, Prague, Czech Republic.
Glucosamine resulted in salutary radiographically measurable changes in joint structure that persisted for years after treatment ended. This is the most likely explanation for the observed reduction in knee replacement, the rheumatologist said at the congress, which was sponsored by the European League Against Rheumatism. Indeed, only 5% of patients on glucosamine had more than 5 mm of joint space narrowing during the 3-year active treatment phase, compared with 14% in the placebo arm. And this degree of joint space narrowing during the first 3 years of the study was associated with a 3.2-fold increased risk of total knee replacement during the subsequent 5 years.
Maxime Dougados, M.D., commented that Dr. Pavelka's report is an exciting development in that it confirms a similar benefit seen in a study previously presented at the annual meeting of the American College of Rheumatology by Jean-Yves Reginster, M.D., of University of Liège (Belgium). That study involved a 3-year off-treatment extended follow-up of a randomized placebo-controlled glucosamine trial; it, too, showed less total knee replacement in patients previously on glucosamine.
“I think with this kind of information, we'll finally be able to convince the medical community that there is proof of a disease-modifying drug in osteoarthritis,” added Dr. Dougados of René Descartes University, Paris.