Hyaluronan Injections for Knee Osteoarthritis

Medically Reviewed by David Zelman, MD on June 14, 2021

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

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

How Do These Knee 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. This leads to decreased symptoms of osteoarthritis.

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 Knee Osteoarthritis Injections

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

  • Physical therapy
  • Exercise
  • Heat or cold
  • Over-the-counter pain relievers

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

Side Effects of Knee Osteoarthritis Injections

Potential side effects of these knee osteoarthritis injections 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.

What to Expect From Knee Osteoarthritis Injections

Treatment with knee osteoarthritis injections ranges from a one-time injection to weekly injections for three to five weeks. Pain relief is usually obtained by four to 12 weeks, and the effect has been shown to last for up to several months. The treatment can be repeated as necessary.