Hyaluronan Injections for Knee Osteoarthritis

Hyaluronic acid injections, also known as hyaluronan injections, are among the treatment options for osteoarthritis of the knee. The treatment, which is described as viscosupplementation, is aimed at improving lubrication of the knee, reducing pain and improving range of motion. 

The injections are given by a doctor in the office or clinic, and one or both knees can be injected at the same time.

Here are 10 things you should know about hyaluronan injections.

Your doctor may recommend that you consider a hyaluronan injection if you have not had adequate pain relief from more conservative treatment options, including:

• Medications
• Exercise/physical Therapy
• Weight loss if you are overweight
• Heat and cold
• Use of an assistive mobility device, such as a cane

Clinical studies have suggested that hyaluronan injections can decrease pain and improve function in people who have with mild to moderate osteoarthritis of the knee. Critics suggest that the studies were flawed, and most doctors believe there is no definitive answer to whether hyaluronan injections are more effective than corticosteroid injections or oral medications.

It is clear that the injections are not a cure, and there is no evidence that suggests hyaluronan injections affect the underlying disease course.

Although hyaluronan injections are not usually recommended before trying other treatment options, the best results usually occur in the early stages of osteoarthritis. If you are in the later stages of the disease or waiting for knee replacement surgery, you may be considered a good candidate for hyaluronan injections, which can provide some relief while you are waiting for your surgery.

The most significant pain relief from knee osteoarthritis is seen between 8 and 12 weeks after the first injection, and pain relief can last up to six months, with some people getting relief for an even longer duration.

If your improvement starts to wane, you may be able to repeat your course of treatment with additional hyaluronan injections.

The U.S. Food and Drug Administration (FDA) has approved the following brands of hyaluronan injections:

• Hyalgan
• Durolane
• Nuflexxa
• Synvisc
• Supartz and Supartz FX
• Gel-One
• Zilretta
• Orthovisc
• Monovisc
• Euflexxa

The different hyaluronan brands are formulated a little differently, and some act faster, while others last longer.

Synvisc-One requires one injection. A complete course of treatment with Synvisc, Orthovisc, or Euflexxa requires three separate knee injections given one week apart. Both Hyalgan and Supartz require five separate injections given one week apart.

Hyaluronan injections are approved for several other conditions, including burns and ulcers. As an injected treatment for osteoarthritis, it is only FDA-approved for osteoarthritis of the knee, not for other regions of the body. Its use for shoulder, hip, and ankle osteoarthritis is being studied.

Hyaluronan injections are not considered safe for children, pregnant women, or nursing mothers. If you are allergic to bird products (i.e., feathers, eggs or poultry) you should talk to their doctor, as the product is extracted from rooster combs.

There should be no adverse interaction with other pain or anti-inflammatory medications that you may be taking, so you do not need to stop taking them if you will have an injection.

You can reduce the chances of experiencing side effects if you rest your knee for the first few days right after your injection. The most common side effects occur around the injected joint are usually mild and include:

• Temporary injection site pain
• Swelling
• Redness and warmth
• Itching
• Bruising

Currently, Medicare will cover hyaluronan injections for the knee only. Medicare also requires X-ray evidence of the knee osteoarthritis. Medicare will only cover hyaluronan injections if given no more frequently than every six months. Private insurance may have different rules, so it is always best to check. Always check for Medicare updates, too.

The ends of the two bones in a normal joint are covered with cartilage and lubricated with synovial fluid, allowing the bones to glide over one another.

Osteoarthritis is a degenerative disease in which the cartilage wears away, and the synovial fluid changes, losing its ability to lubricate the joint. Pain, stiffness, and limited range of motion result, and the condition continues to worsen. Treatment, such as therapy, pain medications, and injections, is directed at reducing pain. It is important to consider all of your options as you cope with osteoarthritis.