Hyaluronic acid injections are used to treat osteoarthritic pain of the knee. It is recommended if the patient wants to postpone joint replacement surgery or when other treatment options are not effective, such as anti-inflammatory pain medications, acetaminophen (TYLENOL), physical therapy, weight loss and corticosteroid injections.
Hyaluronan is a substance normally found in the joint fluid which acts as a lubricant and shock absorber and helps the joint to move smoothly. In an arthritic knee, the quality and quantity of hyaluronan in the joint fluid is reduced. Your doctor can inject hyaluronic acid into the knee to supplement the naturally occurring hyaluronic acid which may help provide temporary pain relief. The injections may only help with the pain but does not reverse or prevent the joint damage.
Hyaluronic acid is injected into the knee joint after draining fluid from it in a doctor’s office. There are many different brands of hyaluronic acid available. While they differ in some ways, none has been shown to work better or worse than another. Let your doctor know if you have a chicken or egg allergy, as a formulation without animal proteins can be used. Depending on which brand is being used, the injections are given weekly for one to five weeks.
Your doctor will check your progress closely to see if the medicine is working and decide if you should continue to receive it. The response that patients have to these injections is variable. For patients who have pain relief, it may take a few days to several weeks to notice an improvement. The amount of time any pain relief lasts also varies. Some patients may have relief in pain for a few months. If the injections are helpful, then they can be repeated in 6 months.
The most common side effects after a hyaluronic acid injection include local reaction with pain, warmth, swelling and difficulty moving the knee immediately after the shot. These symptoms generally do not last long and applying ice helps ease the pain. You should not strain your knee by standing for long periods of time or participating in activities like running, jogging or heavy lifting for one to two days after receiving hyaluronic acid. Call your rheumatology provider if the pain or swelling in the knee persists or becomes worse.
Other less common side effects include bleeding, blistering, burning, coldness, discoloration of skin, feeling of pressure, hives, joint infection, inflammation, itching, lumps, numbness, pain, rash, redness, scarring, soreness, stinging, swelling, tenderness, tingling, ulceration and warmth at the injection site. If a reaction develops to a particular brand, it may be helpful to try a different brand if future treatments are planned.
You should notify your rheumatology provider if you experience any side effects or allergic reactions. Tell your provider if you experience bleeding problems. If you are pregnant or breastfeeding, let your doctor know before starting this medication. The risk in pregnancy and breastfeeding has not been determined. If you develop change in overlying skin, swelling, or worsening pain in the knee where the injection is given, tell your rheumatology provider.
Updated June 2022 by Abin Puravath, MD, and reviewed by the American College of Rheumatology Committee on Communications and Marketing.
This information provided for general education only. Individuals should consult a qualified health care provider for professional medical advice, diagnosis and treatment of a medical or health condition.