Osteoarthritis (OA) is the most common form of arthritis. Typical age of onset is mid to late 40s, with obesity and prior sports injuries increasing the chance of having it.
OA is a painful type of arthritis affecting the joints. It’s a degenerative condition, which means it worsens over time. One of the characteristics of OA is loss of cartilage due to the mechanical breakdown of the joint. This loss of protective cushion can cause debilitating pain and weakness, and may lead to costly joint replacement surgery.
Due to stress throughout life and the possibility of injury, OA is particularly common in knee joints. There is no treatment that can reverse OA or regenerate knee cartilage. However, there are treatments available for those suffering from acute knee pain. Over-the-counter (OTC) pain relievers, physical therapy, diet modification, injections, and joint replacement are all options. What your doctor recommends will be based on the severity of your OA and joint pain.
One treatment option, known as viscosupplementation, involves cushioning the knee joint with injections of a gel-like fluid. The fluid acts as a shock absorber and enables the bones to move more smoothly.
Two possible viscosupplementation therapies are Synvisc-One and Hyalgan. Learn about the similarities and differences between these two therapies, and find out how they compare.
Synvisc-One (hylan GF 20) and Hyalgan (hyaluronic acid) are used to treat severe pain caused by OA of the knee. They both use a naturally occurring substance called hyaluronic acid, found in rooster combs, to cushion and lubricate the joint. The acid also occurs naturally in the human body.
Both drugs are considered “second line” therapies. That means you’ll likely try pain relievers, physical therapy, or weight reduction (if obesity is a factor) before you choose Synvisc or Hyalgan.
Both Synvisc-One and Hyalgan are:
- indicated for treatment of pain due to OA of the knee
- given by injection directly into the cavity surrounding the knee joint
- administered in a doctor’s office
- proven to be safe and effective at reducing pain from OA
Neither therapy will provide immediate pain relief. You’ll likely need a series of injections to experience reduced symptoms.
Even though they are both made of hyaluronic acid produced from chicken combs, Synvisc-One is chemically modified to increase its molecular weight. Hyalgan, on the other hand, is not.
The Synvisc-One shot series requires only three doses. Hyalgan requires five doses. Even though both can reduce OA knee pain for up to six months, one study showed people using Synvisc-One were able to go longer between treatments.
Understanding the possibility of complications and adverse effects is important in making any treatment decision.
Possible side effects of Synvisc-One include:
- pain, redness, swelling at the injection site
- fluid buildup around the joint
- rash (seen less frequently)
According to the FDA, potential complications of Synvisc include:
- injection site pain
- joint effusion
According to the manufacturer, Hyalgan can cause:
- pain around the knee
- knee swelling
- effusion around the knee
Repeat injections of Synvisc or Synvisc-One may cause you to have a hypersensitive reaction known as a "flare." This reaction may be uncomfortable or painful. Hypersensitivity may occur even if you have received a successful shot before.
Who Should Not Take Synvisc-One or Hyalgan?
With either drug, you should tell your doctor if you are allergic to eggs. The injection may not be right for you if your leg is swollen or infected. You should not receive an injection of either treatment if you have an infection.
As we age or experience knee injuries, OA knee pain becomes a real possibility at some point in life. However, it’s reassuring to know that these therapeutic options exist. Both therapies have excellent safety profiles and similar mechanisms of action. As with any drug or therapy, speak to your doctor and weigh the pros and cons of each option so together you can decide with one seems right for you.