Retrocalcaneal Bursitis

Bursae are fluid-filled sacs located at points of contact between bony landmarks and overriding [Page 1213]tendons. There are at least 150 bursae distributed symmetrically throughout the human body. Additional bursae can develop in areas of increased friction. Each bursa acts as a cushion that minimizes friction and allows smooth, gliding interactions between bones and tendons. The bursa is lined by a membrane that secretes synovial fluid. Synovial fluid serves to lubricate the area and facilitate motion in confined joint spaces. Without the bursae, ...