The rotator cuff is a complex of four muscles of the shoulder joint, they start from the scapula and their tendons end at the small and large tuberosity of the humeral head, also called the rotator cuff, which is composed of the tendons of the subscapularis, supraspinatus, infraspinatus and teres minor muscles together, in a cuff shape around the humeral head, during shoulder abduction, the rotator cuff muscle presses down on the humeral head, allowing the upper limb to lift or rotate. Tearing of these tendons is called rotator cuff injury; cadaveric and epidemiological studies have found that the incidence of rotator cuff injury is 20-30% in people over the age of 60, 50% in people over the age of 70, and nearly 80% in people over the age of 80. With the progress of aging, rotator cuff disease will gradually become an important social health problem in the future. The clinical manifestations of rotator cuff disease are mainly pain and weakness of the shoulder joint, mainly abduction weakness, typical fallen arm sign, and limited internal and external rotation of the patient. Diagnosis mainly relies on physical examination and MRI by a specialist. For early diagnosis and treatment, complete rotator cuff tears do not heal on their own, and late rotator cuff tears cause tendon retraction and fattening, which will not be repaired.