&Anserine bursitis=Anserine bursitis: medial aspect of the knee 2 inches below the joint margin. Pain primarily when climbing up stairs. Bursa: fluid filled sack-like structure lined with synovial cells located around the body in areas where friction may develop between a bony prominence and overlying tendons. They allow normal movement and may communicate with a joint space. Bursa's are named by location: Bursitis is typically caused by trauma or overuse, but can be due to infection and inflammatory arthritis (gout or RA). Bursa is characteristically swollen and tender on pressure. Generally, normal range of motion of the joint is maintained.