Knee bursae

Knee bursae are small fluid-filled sacs that reduce friction and cushion pressure points between your bones and the tendons, muscles and skin near your joints. Each of your knees has 11 bursae. Although any of these bursae can become inflamed, knee bursitis most commonly occurs over the kneecap or on the inner side of your knee below the joint.

Anatomy

The knee joint is surrounded by a variety of bursae. These include:

• Prepatellar bursa: Located between the skin and the patella. It reduces friction between the skin and the patella.
• Infrapatellar bursa: Located beneath the patella, between the patella and the patellar ligament.
• Suprapatellar bursa: Located above the patella, between the patella and the quadriceps femoris muscle.
• Pes anserine bursa: Located on the inner side of the knee, between the tibia and the tendons of the sartorius, gracilis, and semitendinosus muscles.

Function

The primary function of the knee bursae is to reduce friction between various tissues of the knee. They achieve this by providing a slippery, cushioning layer that allows tissues to glide over each other without causing damage.

Pathology

Inflammation of the knee bursae is known as bursitis. This can occur due to a variety of causes, including trauma, overuse, infection, or underlying rheumatic conditions. Symptoms of bursitis can include pain, swelling, and reduced mobility of the knee.

Treatment

Treatment for knee bursitis typically involves rest, ice, and nonsteroidal anti-inflammatory drugs (NSAIDs). In severe cases, the bursa may need to be drained or surgically removed.

See also

• Bursitis
• Knee pain
• Knee osteoarthritis