The rotator cuff is a general term for the tendon tissue covering the subscapularis, supraspinatus, infraspinatus, and teres minor muscles in the anterior, superior, and posterior areas of the shoulder joint. Its function is to bring the humeral head closer to the glenoid during upper arm abduction and to maintain a normal fulcrum joint between the humeral head and the glenoid. Rotator cuff injury will weaken or even lose this function and seriously affect the abduction function of the upper extremity. For patients with a short duration of disease (within 3 months), small tears, Neer stage I patients, and elderly people who do not have high functional requirements of the shoulder, non-surgical treatment can be used. Rotator cuff injury can be treated conservatively by rehabilitation methods first. The core problem is to avoid further excessive stress on the shoulder and to exercise the shoulder muscles to restore the balance of rotator cuff and deltoid forces. In addition rest, giving NSAIDS anti-inflammatory and analgesic drugs, physical therapy, local closure, etc. If the injury is severe, the rotator cuff is completely torn, or the effect of conservative treatment is not good for 3 to 6 months, surgery is required.