- Receiving corticosteroid injections in the month before study entry, or receiving hyaluronan in the 6-month period before study entry. No other treatments will result in exclusion, although for patients taking glucosamine and/or chondroitin and/or a non-steroidal anti-inflammatory drug (NSAID), they must have taken these treatments for at least 2 months before study entry and must commit to not start a new treatment during the study.