Hyaluronic acid injections relieve knee pain

9 randomized controlled trials were included in this meta-analysis investigating the efficacy of hyaluronic acid for pain relief in patients with knee osteoarthritis. Only placebo-controlled, double-blind randomized trials were considered for inclusion. Data on pain were pooled at 1 week, 5-7 weeks, 8-12 weeks, and 15-22 weeks post-injection. Results demonstrated significantly greater pain relief with hyaluronic acid compared to placebo at 5-7 weeks and 8-12 weeks, but not in the analysis of data at 15-22 weeks.