The rotator cuff is a combination of muscles and tendons that connect your upper arm bone to your shoulder blade. The rotator cuff also holds your upper arm bone in place in your shoulder socket. The four muscles of the rotator cuff are the subscapularis, supraspinatus, infraspinatus, and teres minor. Each muscle is connected to the humerus by a tendon. Arthroscopic rotator cuff repair surgery is used to repair a rotator cuff tear in one of these tendons.