Hyaluronic Acid Injections

Hyaluronic Acid Injections provide Relief for Arthritis Pain in the Knee. Arthritis afflicts various parts of the body. Nearly 21 million people in the United States have osteoarthritis, which often occurs in the knees. About 30 percent of those over 50 years of age, and 80 percent of seniors older that 65, suffer from the condition. Osteoarthritis can cause not only sharp pain, but also stiffness and a loss of mobility. As knee arthritis advances, patients can develop difficulty descending stairs, walking more than a few city blocks at a time, and misshapen knees. The knee contains hyaluronan, a gel-like substance that lubricates the joint and acts like a shock absorber during exercise. Arthritis sufferers have low levels of this material, resulting in irritation. Hyaluronic acid, which has a similar structure as the naturally occurring substance, can be injected into the knee to relieve pain. The procedure is called viscosupplementation. Hyaluronic acid is manufactured under brand names such as Synvisc, Suppartz, Hyalgan and Orthovisc. When arthritis is diagnosed in the knee, the usual prescription is physical therapy and anti-inflammatory medication. Exercises and stretches specifically designed for the condition can be helpful. Corticosteroid injections are frequently administered. If these methods are insufficient, injections of hyaluronic acid may be warranted.

How Hyaluronic Acid Injections Work?

Viscosupplementation began in Europe and Asia, eventually spreading to the United States and earning the approval of the federal Food and Drug Administration in 1997. When hyaluronic acid is injected, a patient does not experience immediate cessation of symptoms. In fact, the initial shot can cause temporary pain. An ice pack may be needed, but the discomfort generally subsides quickly. Some people have allergic reactions to hyaluronan that cause the knee to swell and become inflamed. In extremely rare cases, infections and bleeding occur. During the first two or three days after the initial injection, it is important to keep weight off the knee. Prolonged standing, heavy lifting and jogging are discouraged. As the series of injections continues, patients gradually feel better because of hyaluronic acid’s anti-inflammatory and pain-relieving properties. The benefits of the injections can last for months. However, hyaluronic acid does not cure arthritis or regenerate cartilage in the knee.

How it is Done?

Before injecting hyaluronic acid, a doctor drains a swelled knee of excess fluids. This is done with a syringe. In most cases, the draining and injection can be performed simultaneously, with the same needle. Sometimes, a separate syringe is required for each purpose. The injections are administered into the cavity that surrounds the joint. As many as five shots, over a period of several weeks, might be necessary to achieve desired outcomes. The series of injections can be repeated about six months later, if needed.

Typical Results Of Hyaluronic Acid (HA) Injection

Viscosupplementation is most beneficial for patients with mild to moderate arthritis. In more advanced cases, hyaluronic acid might not be as effective. It is important to not become discouraged, as it can take weeks for the pain to go away. Most patients experience some relief, though the treatments do not always work for everyone. Researchers measuring the effectiveness of hyaluronic acid viscosupplement injections have reached varying conclusions. One study indicated that patients who took a salt-water placebo experienced the same results as those who received hyaluronic acid injections. However, an analysis of 20 other studies (published in The Journal of Bone and Joint Surgery) found that the injections are effective in reducing pain and improving knee function in patients diagnosed with osteoarthritis.


Hyaluronic acid injections are not recommended in all cases. People with certain types of allergies are advised to try other treatment alternatives. There also could be drug-interaction issues, so patients should tell their doctors about any prescription or over-the-counter medications they are taking. Hyaluronic acid should not be used with disinfectants containing quaternary ammonium salts, such as benzalkonium chloride. Side effects can include difficulty in moving, pain or stiffness in muscles or joints, and swelling or redness in the knee. More serious symptoms (like bleeding, hives, itching and rashes) occur in rare cases. Patients often experience less severe side effects as the treatments progress, because the body is able to adapt to the medicine.


© 2023 Dr. Robert Afra – San Diego Orthopedic Surgery Shoulder – Knee – Elbow