Clinical Question: Are intra-articu...

Clinical Question: Are intra-articular injections of hyaluronic acid (Synvisc) effective for osteoarthritis of the knee?

Setting: Outpatient (specialty)

cogitation Design: Meta-analysis (randomized controlled trials)

Synopsis: In a previous meta-analysis (Lo GH et al. Intra-articular hyaluronic acid in treatment of knee osteoarthritis: a meta-analysis. JAMA December 17 2003;290:3115-21) investigators ground that the use of intra-articular injections of hyaluronic acid to manage osteoarthritis of the knee was minimally effective at best, while a newly come Cochrane Review (Bellamy N, et al. Viscosupplemen-tation for the treatment of osteoarthritis of the knee Cochrane Database Syst Rev 2005; (2):CD005321; whose authors received funding from the manufacturer) construct these injections to be long more effective. Arrich and colleagues examined the same question yet differed from the previous couple analyses by examining separate results (i.e., pain at rest, pain during exercise, and function) rather than grouping them together. The now passing study was sponsored by a national insurance program in Austria.

After a careful literature search, the authors included 22 randomized controll trials. The consideration quality was generally poor: alone seven used concealed allocation; six not absented usable data from an intention-to-treat analysis; 16 had blinded issue assessment; and only four did all of these aspects correctly. Eight studies with a total of 468 patients reported 10 results for pain at rest at pair to six weeks. Six of 10 did not demonstrate any benefit; united poorly designed, industry-sponsored study reported a large benefit for 20 and 40 mg There was too earnestly heterogeneity to combine studies, and poorer quality trials attend toed to find a greater benefit. Nine studies with 1141 patients reported 10 issues for pain during exercise. collection of standing watered data at 10 to 14 weeks and at 20 to 30 weeks plant a statistically--but probably not clinically--significant benefit. Hyaluronic acid had no significant validity on function at any time. In the previous analysis by way of Lo and colleagues, 17 of 22 trials were construct to be industry sponsored.

Bottom Line: The evidence that intra-articular hyaluronic acid helps patients with knee osteoarthritis is of poor quality. Improvements in pain at intermission and pain during exercise are seen in a minority of studies, and those studies are of lower quality than those showing no benefit. There is no evidence of functional improvement. Injections of the like kind as this have a potentially powerful placebo event so any benefit seen in studies without concealed allocation is likely to portray by action the placebo effect rather than any power of the drug. (Level of Evidence: 1a--)

MARK EBELL, MD MS

contemplation Reference: Arrich J, et al. Intra-articular hyaluronic acid for the treatment of osteoarthritis of the knee: systematic review and meta-analysis. CMAJ April 12 2005;172:1039-43

Used with permission from Ebell M Hyaluronic acid unproven for knee osteoarthritis. Accessed online August 22 2005 at: http://www.InfoPOEMs.com.

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