Hyaluronic Acid Injections for the Knee: What to Know First

If you have knee osteoarthritis, your doctor may at some point mention hyaluronic acid injections. Some people hear good things about them from friends, others are unsure or worried about the needle. This article explains what the injections are, how they are given and what research has found so far. It does not tell you whether to have them: that decision belongs to you and your doctor, who knows your knee and your health history.

What is hyaluronic acid?

Hyaluronic acid is a natural part of the fluid inside your joints. It helps to make the fluid smooth and slippery, so that the joint surfaces move easily against each other. In knee osteoarthritis, the properties of this fluid can change. The idea behind the injections is to add a hyaluronic acid preparation directly into the knee joint. You may also hear the term viscosupplementation.

How the injection is given

The injection is usually given in a doctor's office or clinic. The skin is cleaned, and the doctor places a needle into the knee joint, sometimes after first removing excess fluid. Depending on the product, you may get a single injection or a short series spread over several visits. The procedure itself usually takes only a few minutes. Afterwards, follow your doctor's advice about activity, as many doctors recommend taking it easy for a short time.

What research shows so far

Research on hyaluronic acid injections for knee osteoarthritis has given mixed results. Some studies found a modest improvement in pain for some people, while others found results similar to a placebo injection. Products, doses and study designs differ a lot, which makes comparisons difficult. Because of this, professional guidelines do not agree: some advise against using the injections routinely, while others see them as an option for selected patients. If there is an effect, it usually does not appear immediately and it is not permanent.

Possible side effects

Many people have no major problems after the injection, but side effects are possible. The most common are temporary pain, swelling or warmth in the knee. Allergic reactions can occur. A rare but serious complication is a joint infection. Contact your doctor straight away if you develop a fever, or if the knee becomes increasingly red, hot, swollen or very painful in the days after the injection.

Questions to ask your doctor

• Why do you suggest this treatment for me, and what are the alternatives?
• What results can I realistically expect, and how will we judge whether it helps?
• How many injections will I need, and how often?
• What does it cost, and is it covered by my insurance?
• What should I do and avoid after the injection?
• Which warning signs should make me contact you?

It can help to write your questions down before the appointment and to bring someone with you. Our article knee osteoarthritis treatments gives an overview of other options you can discuss.

Injections are only one part of the picture

Whatever you decide, many guidelines put regular exercise and a healthy weight at the center of caring for knee osteoarthritis. Strong thigh and hip muscles take load off the joint; our home strengthening exercises are a good start, and our article on body weight and knee load explains why weight matters. In everyday life, a bamboo knee sleeve can give the knee warmth and a feeling of support, although it is not a treatment. If you wear one, ask your doctor when you can put it on again after an injection.

When to see a doctor quickly

Whether or not you have had an injection, see a doctor quickly if your knee becomes red, hot and swollen, especially with a fever, if it locks or gives way or if you cannot put weight on it. More warning signs are listed in our article when knee pain is serious.

A sleeve you will actually wear

The best sleeve is the one that does not end up in a drawer. The KeenTrove Bamboo Knee Sleeve is made for exactly that:

• soft, breathable bamboo, comfortable even in summer
• fits snugly but does not dig in behind the knee
• does not lock the knee, so you move naturally
• wear it under your clothes during the day and in bed at night

With 60 days to get your money back, you have nothing to lose.

See the bamboo knee sleeve →

Note: this article is for information only and does not replace an examination by a doctor. If you have circulation problems or diabetes, or have recently had knee surgery, talk to your doctor before wearing compression.