Due to the rising number of patients affected by osteoarthritis (OA), appropriate management decisions for minimizing pain and improving physical function for patients with OA are important. Hyaluronic acid (HA) knee injections have become a common tool for the management of OA of the knee, and the number of randomized controlled trials on the efficacy and safety of this treatment is growing. We performed a systematic review of the five published meta-analyses, which include single- or double-blinded randomized trials performed at one center or multiple centers (Level I evidence). Within each meta-analysis, a quality assessment tool for each trial was used based on outcome measures of OA-related pain, disease severity, trial period, and mean efficacy. We analyzed and compared the data collection and qualitative analysis methods, outcomes, and conclusions presented for each meta-analysis. Although they used different strategies, each used scientifically sound methods for analysis of many of the same trials; however, each used a different measure of trial quality and heterogeneity. Despite these differences, all come to a similar conclusion that when the strictest quality tools and interpretation of heterogeneity are used, Level I evidence demonstrates that the use of HA in patients with OA results in modest improvement in validated outcomes.
Level of Evidence: Level I, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.