When the “rotator cuff” tears, surgery may not be necessary. This collection of four muscles and their tendons connects the shoulder blade (scapula) to the upper arm (humerus bone), keeping the ball of the humerus tucked into the shoulder socket. Tears usually occur in one or more of the tendons and can be “partial” or “full-thickness.” Partial rotator cuff tears do not usually require surgery and can be helped with physical therapy. Most often, when an acute full-thickness tear occurs, immediate surgical repair is required. Small full-thickness tears do not always need to be repaired immediately, but may require surgery later if they do not improve after three to six months.