SOFT TISSUE The rotator cuff is a group of muscles and their tendons that act to stabilize the shoulder. The four muscles of the rotator cuff are over half of the seven scapulohumeral muscles. These tendons can become torn following a trauma to the shoulder or it can occur through the "wear and tear" on tendons, most commonly the supraspinatus tendon found under the acromion. To be considered an equal candidate for both implants the rotator cuff must be grossly intact.