BURSITIS Bursitis is inflammation and pain of a bursa. A bursa is a fluid- filled sac that surrounds joints or tendons. A bursa reduces friction by cushioning muscles or tendons and bones that move back and forth across each other. The elbow, hip, knee, shoulder, and other joints contain a cushioning bursa. Treatment consists of Physical Therapy, pharmacological management and steroid injections to reduce the inflammatory process.