Arthritis Foundation Statement on
Hyaluronic Acid Treatment for Osteoarthritis of the Knee

Summary

Hyaluronic acid (currently marketed under the brand names Hyalgan, Synvisc and Supartz) is an FDA-approved treatment for the relief of pain in osteoarthritis (OA) of the knee.  Treatment involves a series of injections given directly into the knee joint.

The Arthritis Foundation believes that hyaluronic acid provides doctors and patients another option for treating OA, a disease that can be painful and difficult to manage.  It should be considered for people with OA of the knee who have not responded well to exercise, physical therapy and simple, over-the-counter (OTC) analgesics, such as acetaminophen and ibuprofen.  Hyaluronic acid also may be considered for individuals who may be at risk for upper gastrointestinal (GI) or kidney complications.

Full Statement

Cartilage in the knee provides a cushion between the bones to allow the joint to move smoothly and without pain.  Hyaluronic acid is naturally produced by the body, and helps to dissipate the shock of high impact movements, to lubricate cartilage and to facilitate movement within the joint.  With OA, the cartilage and other structures of the joint are damaged and over time begin to break down.  During this process the concentration of hyaluronic acid in the joint decreases and may be broken down.  Consequently, lubrication and shock absorption to the cartilage and joint surfaces are thought to be reduced.  This may contribute to the joint stiffness, pain and loss of movement commonly seen in OA of the knees.  Hyaluronic acid injections are intended to replace or supplement the body’s natural hyaluronic acid that has been broken down by OA.  There is no evidence that the treatment alters the progression of knee OA in humans.  There is little information on the long-term effects of repeated cycles of hyaluronic acid injections.

Supplemental hyaluronic acid is a purified extract made from the combs of roosters.  It is a thick   substance that is injected into the joint once a week for three or five weeks, depending on the specific brand of product. This type of treatment is often referred to as joint fluid therapy or “viscosupplementation.”  Mild side effects noted in clinical studies have included local symptoms such as pain, knee swelling, rash and itching at the injection site.  Allergic reactions have been rare.  Clinical studies have shown that hyaluronic acid injections relieve pain better than placebo and are as effective in providing pain relief as non-steroidal anti-inflammatory drugs (NSAIDs).

The Arthritis Foundation believes that while more studies are needed to determine the long-term results of such treatments, hyaluronic acid provides an option for people with OA of the knee who have not responded well to OTC drug treatments or exercise and physical therapy.  It also may be appropriate for those who may be at increased risk for upper GI complications, such as patients who:  are over 65 years old; are taking oral corticosteroids and/or anticoagulants; have a history of peptic ulcer disease or upper GI bleeding; are smokers; and consume high volumes of alcohol.  Hyaluronic acid also may be considered in patients with kidney failure.  As with all arthritis treatments, the Arthritis Foundation recommends that you talk with your doctor about the appropriate option(s) for your individual situation.

For More Information

Contact your local Arthritis Foundation chapter at 1-800-283-7800 for free brochures about managing arthritis.  Find the local chapter that serves your area.

© January 2004 by the Arthritis Foundation. All rights reserved.