Viscosupplementation/Hyaluronic acid injections
Treatment for knee arthritis
Another non operative option for mild to moderate osteoarthritis of the knee is a procedure called viscosupplementation.
In this procedure, a gel-like fluid called hyaluronic acid is injected into the knee joint. Hyaluronic acid is a naturally occurring substance found in the synovial fluid surrounding joints. It acts as a lubricant to enable bones to move smoothly over each other and as a shock absorber for joint loads. People with osteoarthritis have a lower-than-normal concentration of hyaluronic acid in their joints. The theory is that adding hyaluronic acid to the arthritic joint will facilitate movement and reduce pain. The additional hyaluronic acid fills the joint area and increases lubrication in the joint, making joint movement much easier. Also, researchers think the injection of hyaluronic acid may stimulate the body to produce more of its own hyaluronic acid, which will further cushion the joint and make the effects of the injections last longer.
Newer versions of this product require a single injection lasting 6-12 months.
Prior to the procedure, if there is any fluid in the affected joint, it will be removed (aspirated) prior to injecting the hyaluronic acid. Usually, the aspiration and the injection are done using only one needle into the joint.
For the first 48 hours after the shot, you should avoid excessive weight bearing on the leg, such as standing for long periods, jogging or heavy lifting.
You may notice a local reaction, such as pain, warmth, and slight swelling immediately after the shot. These symptoms generally do not last long. You may want to apply an ice pack to help ease them.
Rarely, patients may develop a local allergy-like reaction in the knee. In these cases, the knee may become full of fluid, red, warm, and painful. If this occurs, contact your doctor immediately.
Infection and bleeding are very rare complications of this procedure.
For those who report pain relief with the procedure, it may take several weeks to notice an improvement. One study reported 80% of patients had an 80% reduction in symptoms. How long the effects last varies. Some patients report pain relieving effects for several months following the injections. Some patients report pain relief and improved function with the procedure. Unfortunately some people are not helped by the injections.
Although some patients report relief of arthritis symptoms with viscosupplementation, the procedure has never been shown to reverse the arthritic process or re-grow cartilage.
The effectiveness of viscosupplementation in treating arthritis is not clear. It has been proposed that viscosupplementation is most effective if the arthritis is in its early stages (mild to moderate). While it does provide comfort and pain relief for some people, it may not prevent or even delay the likelihood that a patient will need knee replacement surgery at a later point in their life.
Research in viscosupplementation and its long-term effects continues.