Knee bursitis facts A bursa is a fluid-filled sac that functions as a gliding surface to reduce friction between moving tissues of the body. There are three major bursae of the knee. Bursitis is usually not infec...

Osgood-Schlatter condition (formerly known as Osgood-Schlatter's disease) is a painful condition characterized by tiny, microfractures of the bony bump in the lower leg bone (tibia) where the ligament from the kneecap (patella) is inserted into th...