What is a viscosupplement?
It is a viscous gel-like fluid called hyaluronate (hyaluronic acid). Hyaluronic acid is a naturally occurring substance found in the synovial fluid which bathes joints. Synovial fluid is the source of nutrition for articular cartilage within a joint. It acts as a lubricant to enable bones to move smoothly over each other and as a shock absorber for joint loads. Individuals with osteoarthritis have a lower-than-normal concentration of hyaluronic acid in their joints. The theory is that adding hyaluronate to the arthritic joint will facilitate movement and reduce pain.
- Modifying activities Weight loss
- Pain relief such as paracetamol or nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or combined analgesics which include codeine with paracetamol
- Use of walking aids such as a stick
- Corticosteroid injections
- PRP injections
If a patient has tried all other nonsurgical treatment methods and the pain continues to limit activities of normal daily living, viscosupplementation may be an option especially where a patient has pain as a result of osteoarthritis and does not wish to have surgery.
How effective is a viscosupplement in reducing my knee pain?
This remains controversial as the most recent research has not found viscosupplementation to be effective at significantly reducing pain or improving function. However, many patients continue to report pain relief with the procedure and some are not helped by the injections.
How is the procedure performed?
This is through an intra-articular injection (into the joint). There are several different types of preparations including some that can be administered as a single injection and others that require a course (often of 3 injections) separated by weekly or fortnightly intervals.
Prior to performing the procedure if there is any swelling in your knee, the doctor will remove (aspirate) the excess fluid before injecting the hyaluronic acid.
What can/can’t I do after the injection?
For the first 48 -72 hours after the injection, excessive weight bearing on the leg, such as standing for long periods, jogging, excessive use of stairs, deep squatting or heavy lifting should be avoided.
Are there any side effects or complications?
A patient may notice a local reaction, such as pain, warmth, and slight swelling immediately after the injection. These symptoms generally do not last long. Applying an ice pack will help ease these symptoms and you can also take over the counter medication such as paracetamol as directed.
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.
When can I expect the viscosupplement to work?
As mentioned, some patients will not be helped by viscosupplementation. For those who report pain relief with the procedure, it may take several weeks to notice an improvement. The effect of the injection is variable. Some patients report pain relieving effects for several months following the injections.
If the injections are effective they may be repeated after a period of time, usually 6 months.
Although some patients report relief of arthritis symptoms with viscosupplementation, it has not been shown to reverse the arthritis or regenerate articular 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), but more research is needed to support this. Research in viscosupplementation and its long-term effects continues.