Hyaluronic Acid Injections Are FDA-Approved for Knee Osteoarthritis
Hyaluronic acid injections have been FDA approved for many years as a treatment for knee osteoarthritis. But hyaluronic acid has not been approved for hips or other joints. Researchers have studied the effectiveness of hyaluronic acid injections for the hip and the results were unimpressive.
There are several brands of injectable hyaluronic acid, with Synvisc being the one that was first approved. Euflexxa, Orthovisc, Hyalgan, and Supartz are others. Synvisc-One was approved on February 26, 2009 as a single injection formulation of Synvisc (which requires a series of three injections).
- What Is Viscosupplementation?
- Hyaluronan Injections for Knee Osteoarthritis
- Synvisc Injections May Delay Knee Surgery
- What Is Synvisc-One?
Hyaluronic Acid Ineffective for Hip Osteoarthritis
Hyaluronic acid aims to restore the normal properties of synovial fluid. It has also been suggested that hyaluronic acid may have a protective effect on cartilage, and may reduce the production and activity of chemicals involved in inflammation (such as proinflammatory mediators, matrix metalloproteinases).
According to one study, a single injection of hyaluronic acid is not effective for hip osteoarthritis -- actually, no more effective than placebo. Because hyaluronic acid is rapidly cleared from joints, more than one injection could be needed to provide benefit. Rapid clearance of hyaluronic acid is just one theory of why multiple injections may produce a better result.
Studies that looked at the effectiveness of hyaluronic acid for hip osteoarthritis have been small and scarce. More studies are needed to determine if hyaluronic acid is a suitable treatment option for joints other than the knee.
Effect of hyaluronic acid in symptomatic hip osteoarthritis: A multicenter, randomized, placebo-controlled trial. Arthritis & Rheumatism. March 2009. Richette P et al.