Supplementary methods in the nonsurgical treatment of osteoarthritis.

PURPOSE: This article discusses current evidence in nutraceuticals and viscosupplementation uses in osteoarthritis (OA) treatment.

METHODS: A search was carried out to identify systematic reviews, randomized controlled trials, review articles, and original articles (PubMed and Cochrane Database) about nutraceuticals and viscosupplementation. The keywords used were nutraceuticals, glucosamine, chondroitin, diacerein, avocado, soybean unsaponifiables, nutraceuticals, and viscosupplementation, independently or combined with the terms "review" and "randomized."

RESULTS: Glucosamine hydrochloride has no effect on pain management, although the sulfate formulation has a moderate effect. Diacerein leads to pain relief, with a superior carryover effect when compared with placebo. Avocado and soybean unsaponifiables may have positive effects on knee and hip OA, but long-term results could not be confirmed. Despite the American Academy of Orthopaedic Surgeons' recommendation against the use of hyaluronic acid in OA, some systematic reviews found some benefits in the knee.

CONCLUSIONS: There is no evidence that nutraceuticals or viscosupplementation influences OA's natural progression. However, some of these agents seem to reduce pain and improve function.

LEVEL OF EVIDENCE: Level IV, systematic review of studies with Level I through Level IV evidence.