Knee Bursitis: Symptoms

Knee bursitis — prepatellar bursitis, in the front of the joint — shows up as rapid swelling on the front of the kneecap, with tenderness and warmth over the area and, as the American Academy of Orthopaedic Surgeons puts it, pain with activity but not usually at night.

The signs, in the order they appear

• Swelling at the front of the kneecap, which the AAOS describes as rapid and is often the first thing noticed.
• Tenderness and warmth over the swollen area.
• Pain with activity, and characteristically not at night — a useful contrast with hip bursitis, where night pain is the hallmark. See hip bursitis: symptoms.
• Some loss of motion in certain directions, secondary to the discomfort rather than to a mechanical block.

Chronic cases can go the other way entirely. StatPearls notes that chronic prepatellar bursitis is often painless, because the bursa has had time to expand and accommodate the fluid. A swollen kneecap that barely hurts is a recognized presentation.

Who gets it

Anyone whose job or hobby keeps them on their knees. The AAOS names plumbers, roofers, carpet layers, coal miners and gardeners. Athletes in contact sports are at risk from direct blows, and people with rheumatoid arthritis or gout are more susceptible. The colloquial names in the literature follow the occupations: housemaid’s knee, carpet-layer’s knee, carpenter’s knee.

Bacteria entering through a break in the skin — an insect bite, a scrape, a puncture — can start the whole thing off, which is what makes this joint different from the deeper bursae described in bursitis symptoms.

Infection is common enough to plan for

This is the number worth remembering: StatPearls reports that up to a third of prepatellar bursitis presentations are septic, with a corresponding increase in morbidity. Redness, marked warmth, fever, or pain escalating quickly should be treated as a reason to be seen soon rather than to wait it out. Septic cases are managed with antibiotics — intravenous first when hospitalization is needed, then oral — not with rest and ice.

Treatment for the uninfected kind

Activity modification, ice, elevation and anti-inflammatory medicines come first. If that is not enough, a doctor may drain the fluid and inject a corticosteroid. Surgery to remove the bursa is reserved for persistent cases. Prevention is unglamorous and effective: kneepads for work and contact sports, regular breaks off the knees, and ice after a heavy session.

When to see an orthopedist

Seek evaluation if the swelling does not shrink within a few days, keeps growing, limits knee movement, or comes with redness, intense warmth or fever.

This content is informational and does not replace a medical consultation, diagnosis, or treatment.