Knee bursitis

Overview

Knee bursitis is a condition in which one or more small fluid-filled sacs near the knee joint become inflamed. The sacs are called bursae. Bursae reduce friction and cushion pressure points between bones and tendons, muscles and skin near the joints.

Any of the bursae in the knee can be affected by painful swelling, also called inflammation. But most often, knee bursitis happens over the kneecap or on the inner side of the knee below the joint.

Knee bursitis causes pain and can limit your movement. Treatment often includes a mix of self-care techniques and medical treatments to ease pain and inflammation.

Symptoms

Knee bursitis symptoms vary. They depend on which bursa is affected and what's causing the inflammation.

The affected portion of your knee might feel warm, tender and swollen. You also might feel pain when you move or when you're at rest.

A direct blow to the knee can cause symptoms to come on fast. But knee bursitis often stems from friction and irritation of the bursae. This can occur with jobs that require a lot of kneeling on hard surfaces. So, the symptoms can start slowly and become worse over time.

When to see a doctor

Sometimes, the bursa that lies over the kneecap can become infected. Call your healthcare professional if you have:

A fever or chills along with pain and swelling in your knee.
Long-lasting swelling or a change in the color of the skin around the knee.
Trouble moving or extending your knee.

Causes

Knee bursitis can be caused by:

Frequent and ongoing pressure, such as from kneeling, especially on hard surfaces.
Overuse of the knee or strenuous activity.
A direct blow to the knee.
An infection of the bursa due to bacteria, which could get into the knee through a bruise or a cut.
Medical problems that can happen with osteoarthritis, rheumatoid arthritis or gout in the knee.

Risk factors

Factors that can raise the risk of getting knee bursitis include:

Prolonged kneeling. The risk of bursitis is higher for people who work on their knees for long amounts of time. This includes carpet layers, plumbers and gardeners.
Playing certain sports. Sports that can lead to direct blows or frequent falls on the knee raise your risk of knee bursitis. So do sports that create friction between the knee and a mat. These sports include wrestling, football, basketball and volleyball. Runners also can get pain and inflammation in the bursa that's located on the inner side of the knee below the joint. This is called pes anserine bursitis.
Obesity and osteoarthritis. Pes anserine bursitis often occurs in obese women with osteoarthritis.

Prevention

The following tips can help you prevent bursitis or keep it from coming back:

Wear kneepads. This can help if you often work on your knees or play sports that put your knees at risk. Use padding to cushion and protect your knees.
Take breaks. If you're on your knees for a while, take regular breaks to stretch your legs and rest your knees.
Reach and stay at a healthy weight. This can help take pressure off the knee joints.

Diagnosis

To find out whether you have knee bursitis, your healthcare professional asks you about your medical history. Then you're given a physical exam. Your healthcare professional likely will:

Compare the condition of both knees, especially if only one hurts.
Gently press on areas of your knee to feel for warmth, swelling and the source of pain.
Check the skin over the tender area to look for a change in color or other symptoms of infection.
Carefully move your legs and knees to determine your affected knee's range of motion. This also is done to find out whether it hurts to bend or flex the knee.

Imaging tests

Imaging tests may be needed to find out if a condition other than knee bursitis is the cause of your symptoms. Your healthcare professional might request one or more of the following tests:

X-ray. These can be useful in finding a problem with a bone or arthritis.
MRI. MRI scans use radio waves and a strong magnetic field to make detailed images of structures inside the body. These scans can produce images of soft tissues such as bursae.
Ultrasound. This uses sound waves to make images. Ultrasound can help your healthcare professional find swelling in the affected bursa.

Aspiration

Rarely, a sample of bursa fluid may be taken for testing. A needle is placed into the affected area to drain some of the fluid. This procedure is called aspiration. It might be done if your healthcare professional thinks that you have an infection or gout in the bursa. Aspiration also can be used as treatment.

Treatment

Bursitis often gets better over time, so treatment most often aims to ease your symptoms. But your healthcare professional might recommend one or more treatments. It depends on the cause of your knee bursitis and which bursa is infected.

Medications

If an infection with bacteria causes your knee bursitis, your healthcare professional prescribes medicines called antibiotics. Rarely, surgery to remove the infected bursa is done if medicine doesn't help.

Physical therapy

Your healthcare professional might refer you to a physical therapist or specialist in sports medicine. These professionals can teach you exercises that help the muscles around your knee and leg become more flexible and stronger. This treatment might ease pain and lower your risk of getting repeated bouts of knee bursitis. Protective knee braces might help if you must kneel. And compressive knee sleeves can help control swelling.

Surgery and other procedures

Treatments for knee bursitis treatment that involve injections or surgery include:

Corticosteroid injection. If the bursitis doesn't get better with basic treatments, your healthcare professional may recommend steroid shots. The medicine is injected into an affected bursa to lessen inflammation and relieve pain.
Aspiration. This procedure may be done if medicines and self-care don't help enough. It can help drain extra fluid in the bursa and treat inflammation. Your healthcare professional inserts a needle into the affected bursa and drains fluid into the syringe. Aspiration might cause mild short-term pain. Afterward, you might need to wear a brace that keeps your knee from moving for a period of time. This helps the bursa to heal and lowers the chance of repeat swelling.
Surgery. Surgery to remove an affected bursa is rarely done. But it may be recommended if other treatments don't help or if persistent infection is present. After surgery, you might be able to get back to your usual activities in a few weeks.

Lifestyle and home remedies

To ease pain and discomfort of knee bursitis:

Rest your knee. Take a break from the activity that caused your symptoms. Try not to kneel and make movements that make your pain worse.
Take pain relievers. Some medicines that are sold without a prescription can help ease pain. They're meant for short-term use. They include aspirin, ibuprofen (Advil, Motrin IB, others) or naproxen sodium (Aleve).
Apply ice. Apply an ice pack to your knee for 20 minutes at a time. Do this a few times a day until the pain and warmth in the knee go away.
Try gentle compression. Use of a compressive wrap or knee sleeve can help ease swelling.
Raise your knee. Prop your affected leg on pillows. This helps curb swelling in your knee.
Lose extra weight if needed. This can take pressure off of your affected knee.

Preparing for an appointment

You might start by seeing your primary healthcare professional. Then you might be referred to a doctor who treats other joint conditions, called a rheumatologist. Or you might be referred to an orthopedic surgeon.

Here's information to help you get ready for your appointment.

What you can do

Make a list of:

Your symptoms and when they began.
Key personal information, including the activities and exercises you perform.
All medicines, vitamins and other supplements you take. Include the amounts you take, called the doses.
Questions to ask your healthcare team.

Take a family member or friend along if you can. A loved one can help you remember the information you're given.

For knee bursitis, basic questions to ask your healthcare professional include:

What is the most likely cause of my symptoms?
Are there other possible causes?
What tests will I need?
What treatment do you recommend?
Will I need to limit my activities?
Are there self-care measures I can try?
Are there brochures or other printed material I can have? What websites do you recommend?

Feel free to ask other questions too.

What to expect from your doctor

Your healthcare professional is likely to ask you questions such as:

Did your pain start quickly or slowly?
What work or other activities do you do that might affect your knees?
Does your pain occur or get worse when you do certain activities, such as kneeling or climbing stairs?
Have you recently fallen, been in an accident or gotten hit in the knee?
What treatments have you tried at home?
What effect did those treatments have?