Many common therapies for osteoarthritis of the knee may not benefit patients, according to a review by the Agency for Healthcare Research and Quality (http://www.ahrq.gov/downloads/pub/evidence/pdf/oaknee/oaknee.pdf). The review included data from 53 randomized controlled trials of glucosamine, chondroitin, and hyaluronan and 23 trials of arthroscopy.
Kuehn BM. Knee Therapies Probed. JAMA. 2007;298(20):2361. doi:10.1001/jama.298.20.2361-b