Knee Bursitis – Causes, Treatments, and Prevention

Knee pain can affect your daily activities by making movement difficult and painful. It can also be hard to diagnose the underlying cause of knee pain, adding to your frustration.

However, if you have pain and swelling around your kneecap, there’s a good chance that your pain could be knee bursitis. This condition is caused by inflammation, usually due to overuse.

If you think this may be what you’re dealing with, keep reading. We’re taking an in-depth look at knee bursitis, its causes, treatments, and preventions, so you know how best to move forward with the condition.

What Is Knee Bursitis?

Knee bursitis is when one of the bursae—bursa sacs—in the knee becomes painfully inflamed. It can vary in severity depending on the person and their level of activity.

It can develop over time, and may come and go. You may find that the pain and swelling disappears after self-treatment but flares up again as time passes and your knee takes more strain.

What Is a Bursa Sac?

A bursa sac is a small sac situated inside a joint that holds synovial fluid. They’re located in places where bones, muscles, tendons, ligaments, and skin come together, and their purpose is to cushion these areas, reduce friction, and absorb shock.

When the bursa sacs—bursae—are doing their job correctly, they alleviate friction and keep the joint from becoming inflamed.

When one of these small sacs becomes inflamed, it begins to produce too much synovial fluid. This causes swelling, pressure, and pain in its location.

The knee contains 11 bursae in total. However, only four of these are prone to becoming inflamed and developing knee bursitis. These are:

  • Suprapatellar bursa: Above the kneecap.
  • Infrapatellar bursa: Below the kneecap.
  • Prepatellar bursa: On top of the kneecap.
  • Pes anserinus bursa: Inside and below the kneecap.

You can easily tell which one of the bursae is inflamed by the location of the pain and swelling. In some cases, more than one bursa sac can be inflamed at a time.

Causes of Knee Bursitis

Knee bursitis can occur for a variety of reasons depending on your activity level and lifestyle. Understanding the cause of knee bursitis is the first step to treating and preventing it in the future.

Overuse

The most common reason for knee bursitis is overuse of the knee joint. In some cases, this is the repetitive movement of the joint, like when running or as a result of high-impact activity.

In other cases, pressure on the knee for extended periods can have the same effect. For example, if you spend a lot of time kneeling as a part of your job, the bursae can become inflamed.

Trauma to the Knee

Unexpected trauma to the knee—sporting accidents, car accidents, falls—can cause bursitis to develop as the joint becomes inflamed.

You don’t need to break, dislocate, or sprain the knee for bursitis to develop. Even minor trauma can cause bursitis to develop if your knee isn’t taken care of.

Bacterial Infection

Bursitis as a result of bacterial infection is known as septic bursitis. Bacteria can enter a bursa through a cut or scrape.

Septic bursitis is more common in those with a compromised immune system, but it can happen to anyone.

Septic bursitis can be a serious condition and can spread and cause permanent damage if not treated correctly.

If you start showing symptoms of bursitis after a scrape to the knee, it’s best to consult your doctor.

Other Conditions

Bursitis can develop in the knee as a complication of other conditions such as gout, osteoarthritis, or rheumatoid arthritis. These are common inflammatory conditions and the inflammation can target the bursa as well.

Treatment

Your doctor will most likely recommend home treatment at first. If there is no improvement to your symptoms, or they get worse after a few weeks or months, your doctor may recommend surgery as a last resort.

RICE

The best way to treat knee bursitis is to rest the affected knee as much as you can. Take a break from any exercise that places strain on your knee, like running or sports that involve jumping.

You should also make sure to avoid leaning on your knee. For example, if you usually kneel or squat when gardening, you should instead use a small stool to remove pressure on your knees.

Ice your knees for 10 to 20 minutes, 3 to 4 times a day. This will help to ease the swelling and relieve pain. You can also elevate your knee above the level of your heart—while lying down—to help excess fluid drain away from the joint.

You may also use compression knee sleeves, which will help to increase blood flow and bring oxygen and nutrients to the area, speeding up healing. Other bursitis knee braces also work well.

Cold Compress

A cold compress may be more comfortable if icing your knee joint is uncomfortable for you. You can place a cold compress on the swollen part of your knee for 20 to 30 minutes at a time—until it becomes too warm—4 to 5 times a day.

Non-Steroidal Anti-Inflammatories

You can use over-the-counter non-steroidal anti-inflammatories to manage pain associated with bursitis. However, this should be an occasional form of treatment and not a daily one.

Taping

If you can’t stay off your affected leg, taping your knee can provide extra support to the joint that helps to reduce pain and stabilize the knee. This can be helpful for those who need to be on their feet for work.

Physical Therapy

Your doctor may recommend physical therapy if your range of motion is compromised due to bursitis.

A physical therapist will be able to give you stretches and exercises to do at home that will keep the joint flexible and reduce your pain levels.

Surgery

Surgery is usually a last resort and your doctor will only consider it if your bursitis is not responding to home treatment or physiotherapy.

Your doctor may try a corticosteroid injection first to reduce pain and improve the range of motion before deciding on surgery.

Prevention

If you’ve recovered from knee bursitis and want to prevent it from happening again, follow these tips to keep your knee joints as healthy as possible.

Maintain a Healthy Weight

When you are overweight or obese, your knees take on excess pressure as they support the extra body weight.

Reducing your body weight and maintaining a healthy weight are essential to reduce pressure on your knees.

You can do this by incorporating exercise that’s easy on the knees and maintaining a healthy diet.

Wear Supportive Shoes

The best shoes for bursitis will have a good amount of cushioning to absorb shock and cushion joints.

They should also have a stable heel cup to keep your foot properly in place, and provide adequate arch support for your foot and stability features if needed.

If you already have shoes and don’t want to invest in new shoes, you can use an insert or orthotic instead. You can either get one over the counter, or get a podiatrist to make a custom orthotic for you.

Treat Underlying Conditions

Ask your doctor to check for underlying conditions like rheumatoid arthritis or gout. If these are present but aren’t treated, your bursitis may not go away despite treatment.

Treat underlying conditions properly, and if your bursitis is a result of those conditions, it should heal much more easily.

Be Careful With Exercise

Activity can place excess stress on the knee bursa and cause them to become inflamed. Consider your exercise and make changes if necessary to avoid trauma or repetitive motion of your knee joints.

You should avoid squatting motions when possible. Squatting places pressure on the joint and can lead to knee bursitis.

You should also try to replace movements like leg extensions and leg curls with other motions that don’t involve repetitive bending of the knee.

Try to alternate between different sports so that your knees can take a break. For example, if you play a high-impact sport like basketball, try to mix it up with a low-impact activity like jumping rope that’s easier on the knee joints.

Warm Up Thoroughly

Make sure to stretch your knees thoroughly before engaging in any form of exercise. This will prepare your knees for movement.

Also, make sure you are always performing exercises or sporting movements with the correct form. Using improper form may increase your chances of injury or developing knee bursitis.

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Truong, J., Mabrouk, A., & Ashurst, J. V. (2022). Septic Bursitis. PubMed; StatPearls Publishing.
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