What is Viscosupplementation?

Viscosupplementation is a procedure that involves injecting a thick fluid (hyaluronate) into a joint afflicted with osteoarthritis. Osteoarthritis is a degenerative joint disease affecting 21 million Americans and typically involves the weight-bearing joint of the knees, as well as other joints. According to the American College of Rheumatology, nearly 70 percent of people over age 70 have X-ray evidence of the disease although only half ever develop symptoms.

Why might I need viscosupplementation?
Osteoarthritis is a joint disease that mostly affects the cartilage. Cartilage is the tissue that covers the ends of bones in a joint. When healthy, cartilage allows bones to glide over one another and provides a shock absorber function. The normal knee joint also contains a small amount of fluid called synovial fluid, which is a thick, gel-like substance that cushions the joint and provides lubrication to reduce friction. In osteoarthritis, the surface layer of cartilage breaks down and wears away. Adding to the problem, the synovial fluid in your knees loses its viscosity (ability to lubricate or "oil" the joint). This combination of the deterioration of the cartilage along with the loss of lubrication from changes in the synovial fluid contribute to the pain and stiffness, limitation of joint motion, and some inflammation (for example, redness and swelling) in your knees.

Pharmaceutical companies in the United States have developed three hyaluronic acid-based products (one of the two natural lubricants in synovial fluid) for injection into the knee. These are known by the brand names Hyalgan, Synvisc, and Supartz.

Will viscosupplementation cure my osteoarthrisis?
No, the procedure is not a cure. Currently, there are no cures for osteoarthritis. The theory behind the use of viscosupplementation is based on the belief that this type of product will:

• Improve the lubricating properties of the synovial fluid

• Reduce or stop the pain from osteoarthritis of the joint, and

• Improve mobility and provide a higher and more comfortable level of activity

Who are candidates for viscosupplementation?
Viscosupplementation can be considered if you have not found pain relief from:

• Exercise

• Physical therapy

• Weight loss

• Use of heat (for example, from a heating pad) and cold (for example, from an ice pack)

• Use of a cane or orthotics (such as a heel wedge and other products that relieve the pressure on the knee) and

• Use of analgesics, including acetaminophen (for example, Tylenol); aspirin; prescription or nonprescription nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (for example, Advil, Motrin) and naproxen (for example, Aleve); or corticosteroid injections

Viscosupplementation might be right for you if you:

• Are not receiving adequate pain relief from current treatment

• Cannot take aspirin or other anti-inflammatory drugs like ibuprofen

• Are already taking multiple medications

• Are not an appropriate candidate for knee surgery

When are the viscosupplements given?
The benefits are probably greatest in early osteoarthritis, but viscosupplements can be used at any stage of disease. However, they are usually reserved until other treatment options have been tried and fail to relieve your pain. The supplement is injected directly into your joint. The injection is given in your doctor’s office and the procedure just takes a few minutes to complete. To help make your injection as comfortable as possible, your doctor may apply a local, topical anesthetic first.

How many injections are needed?
To receive a complete course of treatment with Synvisc, your joint must be injected three separate times, one week apart. Five injections, each given a week apart, are required for Hyalgan and Supartz.

What results can I expect?
Whether or not these products "work" is somewhat controversial. While some studies have found these products to improve the pain and function in some people with mild to moderate osteoarthritis of the knee, some clinicians have argued that the design of the clinical trials have been flawed or included too few patients, making interpretation of the results difficult. Other clinicians state that the real questions – do the viscosupplementation products work better than corticosteroid injections or NSAIDs and do they have a role in severe osteoarthritis – have yet to be convincingly answered. Further, there is no proof that viscosupplementation delays or reverses the underlying course of osteoarthritis.

Of patients who seem to be helped by the injections, many report feeling some pain relief during the course of the injections; pain relief is delayed in others. Most patients report the greatest pain relief 8 to 12 weeks after beginning treatment. According to studies reported in the products’ package inserts (studies upon which FDA approval is based), Synvisc and Hyalgan have been proven to provide pain relief from osteoarthritis of the knee for up to 6 months. Some patients have reported benefit beyond 6 months. Supartz was shown to provide pain relief up to 4½ months following the final injection (of the 5 injection series). A small study in patients receiving Hyalgan showed the viscosupplement to be well tolerated by patients when treated every 6 months (with a complete treatment course of five injections) for up to 30 months.

What are the risks or side effects?
The most commonly reported side effects associated with the injections are temporary injection-site pain, swelling, heat and/or redness, rash and itching, bruising around the joint and/or fluid accumulation in the injected knee. These reactions are usually mild (but occasionally are severe) and do not last long. You should avoid any strenuous activities or prolonged (more than 1 hour) weight-bearing activities (such as jogging or tennis) for 48 hours following the injection.

What health history does my doctor need to know about before beginning the treatment?
Before beginning treatment, tell your doctor if you are allergic to products from birds (such as feathers, eggs, or poultry). Also, you should not receive the injections if you have:

• A known allergy to sodium hyaluronate preparations

• An infection or skin disease in the area of the injection site

Because viscosupplements are not drugs, they should not interfere with medications you may be taking, including pain relievers and/or anti-inflammatory drugs; however, remember to talk with your health care provider about any medications you are taking. The safety and effectiveness of Synvisc, Supartz, and Hyalgan have not been determined in pregnant women.