Therapeutic Trajectory of Hyaluronic Acid Versus Corticosteroids in the Treatment of Knee Osteoarthritis: A Systematic Review and Meta-Analysis

Objective. To compare the efficacy of intraarticular hyaluronic acid with corticosteroids for knee osteoarthritis (OA). Methods. Our data sources were Medline, EMBASE, CINAHL, BIOSIS, and the Cochrane database, as well as hand-searched reviews, manuscripts, and supplements. For unpublished data we used author contacts. Randomized trials that reported effects of intraarticular hyaluronic acid versus corticosteroids on knee OA were selected based on inclusion criteria. Two reviewers extracted data independently. Using a random-effects model, we computed effect sizes for pain change from baseline at 2, 4, 8, 12, and 26 weeks. We also performed multivariate analyses accounting for within and between-study covariance. We performed sensitivity analyses for trials that reported intent-to-treat (ITT) analysis and blinding, and directly compared Hyalgan with methylprednisolone. Results. The 7 eligible trials included 606 participants. Five reported ITT analyses. At week 2 the effect size was -0.39 (95% confidence interval [95% CI], -0.65, -0.12) favoring corticosteroids; at week 4 it was -0.01 (95% CI -0.23, 0.21) suggesting equal efficacy. At week 8 the effect size was 0.22 (95% CI -0.05, 0.49) favoring hyaluronic acid, and at week 12 it was 0.35 (95% CI 0.03, 0.66) favoring hyaluronic acid. At week 26 the effect size was 0.39 (95% CI 0.18, 0.59), favoring hyaluronic acid. The multivariate analyses and sensitivity analyses generated consistent results. Conclusion. From baseline to week 4, intraarticular corticosteroids appear to be relatively more effective for pain than intraarticular hyaluronic acid. By week 4, the 2 approaches have equal efficacy, but beyond week 8, hyaluronic acid has greater efficacy. Understanding this trend is useful to clinicians when treating knee OA.