Intraarticular injections for the treatment of osteoarthritis of the knee: basic science, results, and indications

Corticosteroids and hyaluronic acid are the two types of intraarticular injections used to treat osteoarthritis of the knee. Corticosteroids act primarily by decreasing inflammation, whereas hyaluronic acid acts to enhance the mechanical properties of synovial fluid. The exact mechanisms of each are unknown. Clinical trials of corticosteroids indicate they may be useful for short-term relief of pain from osteoarthritis. Clinical trials of hyaluronic acid provide conflicting results. The exact indications for each treatment have not been defined.