Viscosupplements for My Knee Arthritis - What are They?

In osteoarthritis, the cartilage in the joint gradually wears away. During the course of cartilage degeneration, there is inflammation and resultant stiffness and pain. Osteoarthritis may be caused by or aggravated by excess stress on the joint from deformity, repeated trauma, or excess weight. It most often affects middle-aged and older people.

A younger person who develops osteoarthritis may have an inherited form of the disease or may have experienced problems as a result of injury.

In rheumatoid arthritis, the joint becomes inflamed and cartilage may be destroyed as well. Arthritis not only affects joints, it can also affect supporting structures such as:

o muscles

o tendons

o ligaments

Rheumatoid arthritis often affects people at an earlier age than osteoarthritis.
Regardless of the type of arthritis causing knee symptoms, the end result is often the same. A person who has arthritis in the knee may experience pain, swelling, and a decrease in knee motion. A common symptom is morning stiffness that gets better as the person moves around. Sometimes the joint locks or clicks when the knee is bent and straightened, but these signs may occur in other knee disorders as well. The doctor may confirm the diagnosis by performing a physical examination and examining magnetic resonance (MR) scans, which reveal the inner architecture of the knee.

Most often arthritis in the knee is treated initially with pain-reducing medicines, such as analgesics and anti-inflammatory medicines.

Exercise is essential to restore joint movement and strengthen the knee. Losing excess weight can also help people with osteoarthritis.

Glucocorticoid injections are helpful when there is evidence of inflammation.

The normal knee joint produces synovial fluid, a thick slippery substance that nourishes cartilage and allows smooth gliding of the cartilage surfaces. With arthritis, the amount of synovial fluid made by the joint is reduced.

In instances when other therapies do not provide the desired relief, viscosupplements are sometimes used. These are gel-like substances (hyaluronates) that mimic the properties of naturally occurring joint fluid.

These hyaluronates actually supplement the viscous properties of synovial fluid. Injection of hyaluronates is done using either fluoroscopic or ultrasound needle guidance.

Currently, hyaluronate injections are approved for the treatment of osteoarthritis of the knee in those who have failed to respond to more conservative therapy. The number of injections performed varies with the type of viscosupplement used. Usually 5 injections are required for the best response.

Currently, there are five FDA approved hyaluronates:

o Hyalgan

o Synvisc

o Euflexa

o Supartz

o Orthovisc

Sometimes, a physician will perform an arthroscopy before providing viscosupplement. Also, a special type of brace to help unload the narrowed part of the knee may be used to help the viscosupplement work better.

Use for other joints is being studied. Studies have shown effectiveness for the shoulder, hip, and ankle. We published a study a few years ago showing these viscosupplements are effective for osteoarthritis affecting the base of the thumb.