There are several versions of hyaluronan injections -- also called viscosupplementation -- that are used to treat osteoarthritis of the knee. They are injected directly into the joint. They include:

Euflexxa
Hyalgan
Orthovisc
Supartz
Synvisc

They can help reduce the pain in a knee affected by osteoarthritis, increasing mobility and allowing more activity.

How Do These Osteoarthritis Injections Work?

Normal joint fluid contains a substance called hyaluronan. It acts like a shock absorber and lubricant in your joint and is needed to help the joint work properly. Hyaluronan is highly viscous, allowing the cartilage surfaces of the bones to glide upon each other smoothly.

What Joints Can Be Treated With These Osteoarthritis Injections?

Currently, these drugs are only approved for treatment of mild to moderate knee arthritis.

Candidates for These Treatments

These drugs are used to treat osteoarthritis pain in the knee in people who have not found significant relief of their symptoms from:

These drugs can be injected into both knees or just a single knee joint.

Side Effects

Potential side effects include joint swelling and pain. They can't be used by people with skin or joint infections. In addition, most varieties are made from processed chicken or rooster combs and should not be used in people with egg or poultry allergies. Euflexxa, however, is safe to use in people with egg allergies.

Occasionally, a severe reaction with swelling, redness, and pain, called a pseudoseptic reaction, can occur with some forms of these viscosupplementation materials, especially if the course of 3 to 5 injections is repeated.

What to Expect From Treatment

Weekly injections must be given for three to five weeks. Pain relief is usually obtained by eight to 12 weeks and the effect has been shown to last for up to several months. The treatment can be used twice a year.

Reviewed by the doctors at The Cleveland Clinic Department of Rheumatic and Immunologic Diseases.