Conditions

Knee Bursitis: Swelling Over the Kneecap or Below the Knee

Quick answer

Knee bursitis is inflammation of a small fluid sac, called a bursa, that cushions the kneecap or the tendons around the knee. It is often caused by repeated kneeling, a direct knock or overuse, and most cases settle without surgery, says Doha knee surgeon Dr. Pablo Gelber, who treats it at Aman Hospital in Qatar.

What is knee bursitis?

Bursae are thin, slippery sacs that let skin, tendons and muscles glide over bone. The knee has several. When one becomes irritated it fills with fluid and becomes swollen and tender.

The three most commonly affected are the prepatellar bursa in front of the kneecap (sometimes called housemaid's knee), the infrapatellar bursa just below the kneecap, and the pes anserine bursa on the inner side of the shin, just below the joint. Unlike a Baker's cyst or a swollen joint, bursitis usually sits outside the knee joint itself.

Symptoms in patients' own words

"There's a soft, squishy bump right on the front of my kneecap"
"It hurts when I kneel"
"The inside of my knee below the joint is sore on the stairs"
"It aches at night when my knees touch"
"The lump has gone red, hot and painful", which may mean infection

The knee usually still bends and straightens fairly well, which helps distinguish bursitis from a problem inside the joint.

Causes and who gets it

Prepatellar bursitis is usually caused by pressure or friction from repeated kneeling. In Qatar this includes tilers, plumbers, electricians and other manual and industrial workers, carpet layers, gardeners, and people who kneel a great deal at home. Frequent kneeling during prayer on a hard surface can contribute in some people. A fall onto the kneecap, for example on a court or on the street, can cause sudden bursitis with bleeding into the sac.

Pes anserine bursitis is common in runners, in people with knee osteoarthritis, in people who are overweight and in women in middle age. It is often linked to tight hamstrings and weakness around the hip and thigh.

Bursitis can also become infected through a small cut or graze over the kneecap. Gout and inflammatory arthritis are less common causes.

Diagnosis

Dr. Gelber makes the diagnosis mostly from the history and examination: where the swelling is, whether it is warm or red, and whether the knee joint itself is swollen or damaged.

An ultrasound confirms fluid in the bursa and can guide drainage. X-rays may be used to look for arthritis or a fragment of bone after a fall, and an MRI is occasionally needed when pes anserine pain may be coming from a meniscus tear or a stress injury instead. If infection is suspected, fluid is drawn from the bursa and tested.

Non-surgical treatment

Avoid kneeling and direct pressure; use a thick cushion or knee pads if kneeling cannot be avoided at work
Ice for 15 to 20 minutes a few times a day and gentle compression
Anti-inflammatory medicine for a short period, if suitable for you
Physiotherapy for pes anserine bursitis: hamstring stretching, hip and quadriceps strengthening and adjusting running load
Drainage of a large bursa, and in selected non-infected cases a steroid injection

Infected bursitis needs antibiotics, and sometimes drainage, and should be treated promptly.

Surgical treatment

Surgery is uncommon. It is considered when bursitis keeps returning despite good non-surgical care, or when an infected bursa does not respond to antibiotics and drainage. The bursa can be removed through a small incision or with keyhole techniques. The body usually forms a new, healthy gliding layer afterwards.

Recovery and when to see a specialist in Doha

Most non-infected bursitis settles over a few weeks once pressure is removed, although a thickened bursa can take longer to shrink. Pes anserine bursitis often improves over several weeks of physiotherapy. Recovery after surgery to remove a bursa usually takes a few weeks, with the wound protected from kneeling until it has healed.

See a specialist if swelling keeps returning, is not improving after two to three weeks, or limits your work or prayer. Seek same-day care if the area becomes hot, red and increasingly painful, if red streaks spread up the leg, or if you develop a fever. Dr. Gelber sees patients at Aman Hospital in Doha.

Frequently asked questions

Can kneeling for prayer cause bursitis?

In some people, frequent kneeling on a hard surface adds pressure over the kneecap and can contribute. A thicker prayer mat, cushioning, or praying on a chair while it settles usually helps, and the bursitis often calms down once pressure is reduced.

Should the fluid in my knee bursa be drained?

Not always. Small, non-infected bursitis often settles with rest from kneeling, ice and time. Drainage is considered for large, uncomfortable swellings or when infection needs to be ruled out, and the fluid may return if pressure continues.

How do I know if my knee bursitis is infected?

Warning signs are increasing redness, heat, pain, a cut or graze over the swelling, red streaks up the leg and fever or feeling unwell. These need prompt medical review, usually the same day, because infected bursitis needs antibiotics.

Glossary