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Knee Pain

Knee Bursitis
- Pes Anserine Bursitis

Bursae are small, jelly-like sacs that are located throughout the body, including around the shoulder, elbow, hip, knee, and heel. They contain a small amount of fluid and are positioned between bones and soft tissues, acting as cushions to help reduce friction.

Pes anserine bursitis is an inflammation of the bursa located between the shinbone (tibia) and three tendons of the hamstring muscle at the inside of the knee. It occurs when the bursa becomes irritated and produces too much fluid, which causes it to swell and put pressure on the adjacent parts of the knee.

Pain and tenderness on the inside of your knee, approximately 2 to 3 inches below the joint, are common symptoms of pes anserine bursitis of the knee.


Bursitis usually develops as the result of overuse or constant friction and stress on the bursa. Pes anserine bursitis is common in athletes, particularly runners. People with osteoarthritis of the knee are also susceptible.

Several factors can contribute to the development of pes anserine bursitis, including:

  • Incorrect training techniques, such as neglecting to stretch, doing excessive hill running, and sudden increases in mileage

  • Tight hamstring muscles

  • Obesity

  • Being duck-footed or having knock knees

  • Osteoarthritis in the knee


The symptoms of pes anserine bursitis include:

  • Pain slowly developing on the inside of your knee and/or in the center of the shinbone, approximately 2 to 3 inches below the knee joint.

  • Pain increasing with exercise or climbing stairs

  • Puffiness or tenderness to the touch in this area


During the physical examination, your doctor will inspect your affected knee and compare it to your healthy knee. They will examine your knee, checking for tenderness, and will also assess the range of motion in your knee and whether pain prevents you from bending it.


Your doctor may employ the following tests:

  • X-rays. Your doctor may order X-rays to make sure there is not a fracture or other bony problem that is causing your symptoms.

  • Other imaging tests. The diagnosis of bursitis is usually made on physical examination, but computerized tomography (CT) and magnetic resonance imaging (MRI) scans may be ordered to check for other soft tissue injury.

  • Aspiration. If your doctor is concerned about the possibility of infection, they may aspirate (draw fluid with a needle) from the bursa and send this sample to the lab for analysis.

Non-surgical treatments

Nonsurgical treatment is usually effective as long as the bursa is simply inflamed and not infected:

  • Using the RICE (rest, ice, compression, elevation) method: The RICE method involves resting your knee, icing your knee, wearing an elastic bandage around your knee (compression) and elevating your knee while you’re resting. This helps to reduce pain and swelling.

  • Taking pain relievers: Your healthcare provider may recommend taking pain relievers (non-steroidal anti-inflammatory medications, or NSAIDs) to help reduce pain and swelling in your knee. Acetaminophen can be used as an alternative if you cannot tolerate NSAIDs or are allergic.

  • Aspiration & cortisone injection: If the swelling and pain do not respond to the above measures, your doctor may drain (aspirate) the bursa with a needle, then inject the bursa with a corticosteroid (cortisone injection). The corticosteroid is an anti-inflammatory drug that is stronger than medications that can be taken by mouth.

  • Antibiotics: Infectious bursitis is initially treated with antibiotics. 

  • Surgical drainage: This is required if infectious bursitis does not respond to antibiotics alone.