any structural anomaly of the connective tissue between tendon and bone insertion sites; the area 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