A pre-patellar bursa is a space between the tissues in front of the knee which is enclosed like an envelope and lined with lubricating cells.
This is an illustration of the inside of the knee from a side view as if it was cut through the middle. You can see that there are several bursae around the knee. The pre-patellar bursa is just in front of the kneecap.
Function of the pre-patellar bursa
As the knee bends and straightens with ordinary activities, the bursae - being lubricated - allow the tissues to slide and accommodate the activity. When a bursa becomes inflamed, perhaps from impact or involvement in repeated movement, it may fill with fluid and become painful, and range of motion of the knee may be reduced.
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