The efficacy of glucosamine and/or chondroitins in knee osteoarthritis (OA) has been controversial.  A recent large, randomized, multicenter trial (the GAIT trial) found no symptomatic or structure-modifying benefit of glucosamine or chondroitin, alone or in combination.  However, prior studies conducted in Europe using different formulations have suggested the possibility of structure modification with chondroitin sulfate [...]