Clinical question Is a single intraarticular injection of hyaluronic acid effective in reducing pain or improving function in patients with symptomatic degenerative joint disease (DJD) of the hip?
Bottom line A single intra-articular injection of hyaluronic acid to the hip of patients with symptomatic DJD was no better than placebo in decreasing pain or improving function. (Level of evidence = 2b)
Synopsis To be eligible for this study, patients had to be aged 30 to 80 years; have radiographically confirmed, moderately severe DJD involving the hip; have had daily pain for at least 1 month with a severity of at least 40 mm on a 100-mm visual analog scale (VAS) in spite of treatment with acetaminophen or NSAIDs. These patients were randomly assigned (concealed allocation) to receive a single fluoroscopically guided intra-articular injection of hyaluronic acid or a placebo. After the injection, patients could use NSAIDs or stronger analgesics only if the pain did not respond to optimal doses of acetaminophen (4 g/d). The main outcomes—change in pain ratings and some measures of function—were analyzed by intention to treat. The researchers estimated they would need 122 patients to find a difference in pain response of 20 mm on the VAS. This is the minimal clinically important difference for pain scores. They only studied 85 patients because recruitment was slow and their supply of medication had expired. At the end of 12 weeks, the patients who received active therapy saw their pain scores decrease by the same amount as those who received placebo (average = 8 mm compared with 9 mm). Additionally, approximately one third of the patients in each group were categorized as responders (not defined by the researchers).
Richette P, Ravaud P, Conrozier T, et al. Effect of hyaluronic acid in symptomatic hip osteoarthritis: a multicenter, randomized, placebo-controlled trial. Arthritis Rheum. 2009;60(3):824-830.