Shoulder arthroscopy is surgery that uses a tiny camera called an arthroscope to examine or repair the tissues inside or around your shoulder joint. The arthroscope is inserted through a small incision (cut) in your skin. The rotator cuff is a group of muscles and tendons that cover your shoulder joint. These muscles and tendons hold your arm in your ball and socket shoulder joint, and they help you move your shoulder in different directions. The tendons in the rotator cuff can tear when they are overused or injured.