Rotator cuff tear may have significance include os acromiale and acromial spurs. Environmental factors implicated include increasing age, shoulder overuse, smoking, and any medical condition that affects circulation or impairs the inflammatory and healing response, such as diabetes mellitus. Intrinsic factors refer to injury mechanisms that occur within the rotator cuff itself. The principal is a degenerative-microtrauma model, which supposes that age-related tendon damage compounded by chronic microtrauma results in partial tendon tears that then develop into full rotator cuff tears. As a result of repetitive microtrauma in the setting of a degenerative rotator cuff tendon, inflammatory mediators alter the local environment, and
Synovial sheath Synovial sheath A synovial sheath is one of the two membranes of a tendon sheath which covers a tendon. The other membrane is the outer fibrous tendon sheath. The tendon invaginates the synovial sheath from one side so that the tendon is suspended from the membrane by the mesotendon, through which the blood vessels reach the tendon, in places where the range of movement is extensive. The mesotendon disappears or remains in the form of narrow tendinous bands as threads known as vincula tendina. The synovial sheath is found where the tendon passes under ligaments and through osseofibrous tunnels; their