What is knee bursitis?

Knee bursitis is the inflammation of one or more of the small sacs of fluid (bursa) that cushion the knee joint. 

These small sacs of fluid help to reduce friction between the knee joint, surrounding muscles and ligaments. 

When the bursa becomes inflamed it causes the knee to swell which can be very painful and limit movement.

Knee bursitis usually affects the bursa over the kneecap (prepatellar bursitis) commonly known as housemaid’s or carpenter’s knee. 

Knee bursitis is also fairly common on the inner side of the knee (pes anserine bursitis).

What causes knee bursitis?

There are several causes of knee bursitis including: 

• Frequent and sustained pressure to the knee e.g. kneeling on hard services
• Frequent trauma to the knee - direct blow to the knee or overuse, for example rugby players have a higher risk of knee bursitis
• Arthritis - you’re more at risk of developing knee bursitis if you have osteoarthritis, rheumatoid arthritis or gout
• Infection - bacterial infections can cause knee bursitis which if left untreated can lead to infection in the joint (septic arthritis), infection in the bone (osteomyelitis) and cellulitis

Who is at risk of developing knee bursitis?

Some people have a slightly higher risk of developing knee bursitis than others including: 

• People whose work involves a lot of kneeling - carpenters, plumbers, gardeners
• Sportsmen and women - football players, wrestlers, volleyball players, runners
• People with osteoarthritis and obesity - if you are overweight and have osteoarthritis you’re at a higher risk of developing inner knee (pes anserine) bursitis
• People who have low immune system function - if you have diabetes, are having chemotherapy or have HIV you have a higher risk of bacterial infections and knee bursitis

What are the symptoms of knee bursitis?

Symptoms of knee bursitis vary according to the cause and which bursa (sac) is affected, and your knee might feel:

• Warm
• Tender
• Swollen
• Painful when you move it (or rest it)

If you’ve recently had an injury to your knee, bursitis symptoms may develop rapidly. 

If you have bursitis as a result of your job or habitual movements, your symptoms may begin gradually and get worse over a period of time. 

Try to use a cushion or padded knee support to avoid knee bursitis caused by kneeling on hard surfaces.

Call your doctor or specialist immediately if you experience the following symptoms which can be a sign of septic bursitis:

• Extreme warmth
• Extreme tenderness at the joint
• Redness of the skin over the bursa
• Fever or chills
• General feeling of sickness

Septic knee bursitis usually affects the prepatellar bursa at the kneecap. Infection may be due to a cut, scrape, itching or an insect bite.

How is knee bursitis diagnosed?

To diagnose knee bursitis, one of our orthopaedic specialists will examine your knee and ask you about your overall health.

They’ll need to know about your lifestyle and any trauma you think you may have had to your knee.

Your specialist may ask you to take a blood test to check for inflammatory markers so they can rule out any underlying conditions, such as arthritis. 

They may send you for an X-ray, MRI or ultrasound scan so they can visualise the soft tissue and take a closer look inside your knee joint.

If your orthopaedic specialist suspects you have septic bursitis they will draw out (aspirate) fluid from your knee, so it can be immediately sent to our pathology department for analysis.

What is the treatment for knee bursitis?

Depending on the cause of your knee bursitis your specialist may offer you treatment such as:

• Antibiotics - to treat septic bursitis
• Corticosteroid injections - to reduce inflammation
• Aspiration procedure - to draw out any excess fluid on the knee
• Physiotherapy, hydrotherapy and sports therapy to alleviate pain and strengthen the knee
• Help and support to achieve and maintain a healthy weight
• Surgery to remove the bursa - if it doesn’t respond to medication

At The London Clinic we have a dedicated weight management clinic and state-of-the-art physiotherapy and hydrotherapy facilities where our experienced and friendly team can help you achieve your goals.