Appropriate Use Criteria for Hyaluronic Acid in the Treatment of Knee Osteoarthritis in the United States journals.sagepub.com Efficacy and safety of single injection of cross-linked sodium hyaluronate vs. three injections of high molecular weight sodium hyaluronate for osteoarthritis of the knee: a double-blind, randomized, multi-center, non-inferiority study ncbi.nlm.nih.gov