Healing Rotator Cuff Tear
Rotator cuff tears are tears of one or more of the four tendons of the rotator cuff muscles. A rotator cuff injury can include any type of irritation or damage to the rotator cuff muscles or tendons. Rotator cuff tears are among the most common conditions affecting the shoulder. The tendons of the rotator cuff, not the muscles, are most commonly torn. Of the four tendons, the supraspinatus is most
frequently torn as it passes below the acromion; the tear usually occurs at its point of insertion onto the humeral head at the
greater tubercule.

Many rotator cuff tears cause no pain nor produce any symptoms, tears are known to have an increasing incidence with increasing age. The most frequent cause of rotator cuff damage is age related degeneration and less frequently by sports injuries or trauma. Partial and full thickness tears have been found on post mortem studies and on MRI studies, in people who do not have a history of shoulder pain or symptoms.

Rotator cuff disease may be initiated, or proliferated, by factors that are both extrinsic and intrinsic in nature: Extrinsic factors
are grouped into anatomical and environmental. One of the most acclaimed anatomical factors is the morphologic characteristics of the acromion. Hooked, curved, and laterally sloping acromions are strongly associated with cuff tears and may contribute by causing tractional damage to the tendon. On the other hand;, flat acromions may have a insignificant involvement in cuff disease and consequently are often best treated conservatively. The development of these different acromial shapes is likely both genetically inherited and acquired from other causes. With acquired causes, only age has been positively correlated to progression from a flat to a curved or hooked acromion. The nature of mechanical activities, such as sports involving the shoulder, along with frequency and intensity of such a sport may be responsible for the adverse development. Sports such as bowling in cricket, swimming, tennis, baseball, and kayaking are primarily responsible. Moreover, a progression to a hooked acromion may simply be an adaptation to an already damaged, poorly balanced rotator cuff that is creating increasing stress on the coracoacromial arch. Other anatomical factors that may have significance include os acromiale and acromial spurs. Environmental factors implicated include increasing age, shoulder overuse, smoking, and any medical condition that impairs the inflammatory and healing response such as diabetes mellitus.

Intrinsic factors encompass the range of injury mechanisms that occur within the rotator cuff itself. Chief among these 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 oxidative stress induces tenocyte apoptosis causing further rotator cuff tendon degeneration. A neural theory also exists that suggests neural overstimulation leads to the recruitment of inflammatory cells and may also contribute to tendon degeneration.

Adopted From wikipedia