The rotator cuff is an important structure between the peak of the shoulder and the head of the humerus. It is composed of four tendons that are closely connected: the supraspinatus tendon, the infraspinatus tendon, the lesser circular tendon and the subscapularis tendon. These tendons wrap around the humeral head and resemble a “cuff”, hence the name rotator cuff, which is an important structure for stabilizing the humeral head and shoulder movement. What is a rotator cuff injury? The primary injury to the rotator cuff is usually to the tendon parenchyma of the rotator cuff, followed by bursitis or injury to the bursa or cartilage beneath the tendon. Rotator cuff injuries include both acute trauma and chronic injuries. The former is rare and occurs mainly in young adults, often in sports or labor operations, and is characterized by a tearing sound, local swelling, subcutaneous bleeding, local pain limited to the top of the shoulder and dissipating to the deltoid stops, and significant pressure pain between the greater tuberosity and the acromion. Chronic injury is very common and is the main type of rotator cuff injury, mostly occurring in the elderly. It is a rupture of the tendon due to cumulative injury on a degenerative basis. Patients often have no obvious history of trauma, and pain is their main symptom, with significant pain at night, usually accompanied by weakness of the affected shoulder joint. Patients with painful abduction and external rotation or internal rotation of the shoulder joint or with weakness should consider the possibility of rotator cuff injury and actively seek medical consultation to clarify the diagnosis. Ultrasound and MRI can reveal the location and extent of rotator cuff tears, which can help diagnose and guide surgery. How is a rotator cuff injury treated? Treatment for rotator cuff injuries includes two main categories: non-surgical treatment and surgical treatment. Non-surgical treatment includes limiting joint movement, physical therapy, and oral anti-inflammatory and pain medication. However, conservative treatment of rotator cuff injury has limited effect. For cases where conservative treatment is ineffective, surgery should be chosen early. Traditional incisional surgery is very traumatic, but the development of arthroscopic techniques and equipment has now made it possible to clean the subacromial space with minimal trauma, shape the subacromial surface, and make accurate and firm suture repair of rotator cuff tears. Our department has accumulated a lot of clinical experience in the minimally invasive treatment of this disease, with a short recovery period and satisfactory long-term results.