enthesis

The connective tissue between tendon and bone insertion sites, which acts to transmit tensile load from soft tissues to bone. They may be of the dense fibrous connective tissue or fibrocartilage type; fibrous entheses attach directly to bone or periosteum primarily via fibrous tissue, and fibrocartilaginous entheses attach to bone through a transitional layer of fibrocartilage from the fibrous tendon tissue the sites where tendons or ligaments insert into the bone. Recurring stress or inflammatory autoimmune disease can cause inflammation or occasionally fibrosis and calcification of the enthesis.