Hyaluronic Acid Injections – What You Should Know
If pain-relieving medication and other treatments do not work well to relieve knee pain caused by osteoarthritis, you may benefit from one or more hyaluronic acid injections. The injections contain a synthesized substance similar to one that’s present naturally in the joints, where it acts like a shock absorber and lubricant.
Find out more about the hyaluronic acid injections offered by Sports Med London. We’ll take a look at what they are, how they work, and what you need to know about receiving them.
What Is Hyaluronic Acid?
Known as a viscosupplement, hyaluronic acid is made mostly of sugar. Its main function in the synovial fluid that surrounds joints such as the knee is to bind water and to act as a lubricant. The water-loving quality of hyaluronic acid led to it being described as “nature’s moisturiser.”
When there are normal concentrations of hyaluronic acid in the synovial fluid, the fluid functions like an elastic shock absorber when you move your joints rapidly. It also functions like a viscous lubricant when you move your joints slowly. The result is less friction and stress on your joints’ articular cartilage, which is the cartilage on the ends of the bones where they meet and form joints.
What Hyaluronic Acid Injections Do
Hyaluronic acid injections increase the amount of the acid present in the synovial fluid in your knee. Some of the effects include:
- Relief from pain
- Joint surfaces receive more nutrition
- Better shock absorption
- Better lubrication
- Reduction of synovial inflammation
- Promotion of your body’s production of hyaluronic acid
- Reduction in cartilage erosion
Depending on how advanced the osteoarthritis in your knee is, you may need one injection or a course of injections. If a course is recommended, you will receive three or four injections in your knee, each of them a week apart.
How Long Do The Effects Last?
The duration of the effects of hyaluronic acid injections varies from person to person. The effects have lasted for as few as 4 months in some patients with mild to moderate osteoarthritis, and for as long as 12 months in others. If you need a repeat course of injections, you typically will receive it at least six months after the first course.
Many patients feel pain and warmth and/or experience swelling in the injected area after receiving the treatment. This is normal and usually short-lived. However, if you want to manage the pain, you can use over-the-counter painkillers and/or apply an icepack to the area.
You’ll also need to avoid various activities for some time after receiving the injections. Find out about more about that below.
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.
In its early stages, arthritis of the knee is treated with conservative (nonsurgical) methods. These include:
- 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.