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
Glenohumeral ligaments capsule is strengthened in front by two bands derived from the tendons of the Pectoralis major and Teres major respectively. During abduction of the arm the middle and inferior ligaments become taut while the superior ligament relaxes. The radius of curvature of the head of the humerus is greater superiorly than inferiorly, which further stretches these ligaments so that they keep the articular surfaces of the joint in their close-packed position. During abduction the greater tubercle of the humerus comes in contact with the upper margin of the glenoid cavity, which limits maximum abduction. By rotating the humerus laterally, this