Rotator cuff tear infraspinatus, teres minor, and subscapularis, may also be injured. The amount of stress needed to tear a rotator cuff tendon acutely will depend on the underlying condition of the tendon prior to the stress. In the case of a healthy tendon, the stress needed will be high, such as a fall on the outstretched arm. This stress may occur coincidentally with other injuries such as a dislocation of the shoulder, or separation of the acromioclavicular joint. In the case of a tendon with pre-existing degeneration, the force may be surprisingly modest, such as a sudden lift, particularly with the arm
Rotator cuff tear hemorrhage of the tendon and bursa. Stage II involved tendinitis and fibrosis of the rotator cuff in 25- to 40-year-olds. Stage III involved tearing of the rotator cuff (partial or full thickness) and occurred in those older than 40 years. For surgical purposes, tears are also described by location, size or area, and depth. Further subclasses include the acromiohumeral distance, acromial shape, fatty infiltration or degeneration of muscles, muscle atrophy, tendon retraction, vascular proliferation, chondroid metaplasia, and calcification. Again, in surgical planning, age-related degeneration of thinning and disorientation of the collagen fibers, myxoid degeneration, and hyaline degeneration are considered. However,