Injured Bursas in the Knee

By Ben Benjamin, PhD

Question: True or False?

The prepatellar bursa is located just superior to the kneecap.

Question: True or False?

The infrapatellar bursa is located inferior to the kneecap on the anterior surface of the patella ligament, right under the skin surface.

Question: True or False?

The suprapatellar bursa is located right on the anterior surface of the kneecap.

Answer: All three statements above are false.

All three of these bursas play a role in the smooth functioning of the knee joint.

Knowing the exact locations of these bursas and being able to tell when they are injured will help you better evaluate clients that present with knee pain. Deep massage or friction therapy will either do nothing, or worsen the pain of a client suffering from bursitis in the knee. Therefore, it is very important to distinguish between a soft-tissue injury, where hands-on treatment is appropriate, and an injury that is not.

The prepatellar bursa, located just beneath the skin on the anterior surface of the patella, protects the bony surface of the patella. This bursa is usually injured by a high-impact fall. When injured, it swells like a balloon on top of the kneecap, and is red and painful when touched, even gently. Hands-on treatment is not effective for this injury.

The infrapatellar bursa is located inferior to the patella within the knee joint, posterior to the patella ligament. It cushions the patella ligament and is painful when kneeled upon. When swollen and inflamed, it is also difficult to bend the knee fully; however, it does not limit extension of the knee. This bursa is often injured along with the quadriceps mechanism above or below the patella. The suprapatellar bursa is located proximal to the patella at the base of the anterior thigh. When inflamed, it is usually hot, visibly swollen and painful to the touch. The swelling in the bursa limits the ability of the knee to fully flex.

Very little is definitively known about why a bursa becomes inflamed and swollen. Causes could range from impact trauma to subtle misalignments of the knee. My best guess is that excessive movement, caused by loose medial and lateral collateral ligaments and loose anterior and posterior cruciate ligaments, often causes the bursa to become irritated and inflamed.

Treatment options for bursitis are limited. If several months of rest do not eliminate the pain, anti-inflammatory injections are usually indicated and effective.