The shoulder joint is the joint with the largest range of motion in the human body, and all the complex movements of the upper extremities cannot be achieved without the participation of the shoulder joint, but at the same time, the shoulder joint is the most “fragile” joint in the human body, and there are many opportunities for injury; the incidence of shoulder joint disease is quite high, and trauma, sports injuries and chronic strain can lead to disease. Almost every older person has a history of shoulder problems, and sports enthusiasts and professional athletes are more likely to have shoulder injuries. However, it is relatively difficult to diagnose shoulder disorders. X-rays, including MRI, can only obtain relatively limited information, and conventional methods of physical examination are limited and poorly reproducible, so many shoulder disorders are generally diagnosed as “frozen shoulder”. In addition, the traditional surgical approach has a wide incision area, is more traumatic, slower to recover, and inevitably causes joint adhesions, resulting in permanent functional limitations. Therefore, for a long time, the diagnosis of shoulder joint is ambiguous, and the treatment is mostly in favor of conservative treatment such as physical therapy and closure, which is ineffective. The simplest daily activities such as combing hair, putting on and taking off clothes, and bathing became “difficult” problems, seriously affecting the patient’s ability to take care of himself. Since 1919, when arthroscopy was first successful in the diagnosis and treatment of knee diseases, it has been rapidly promoted worldwide for its minimally invasive surgery, clear diagnosis, precise treatment and rapid rehabilitation, and has been called three milestones in the field of orthopedics in the 20th century, together with artificial joint technology and AO internal fixation technology. In the late 1980s, with the help of shoulder arthroscopy, not only the correct diagnosis rate of shoulder diseases could be greatly improved, but also the encouraging results of microscopic treatment were achieved. With the help of shoulder arthroscopy, through the camera lens that extends into the joint, it is possible to examine all parts of the shoulder joint intuitively without blindness, which greatly improves the accuracy of diagnosis of shoulder joint diseases; without cutting open the joint, it avoids damaging the important structures of the joint, which plays a good role in promoting the recovery of joint function. . Acute injuries to the shoulder joint are commonly caused by lifting and pulling heavy objects, supporting the shoulder when falling, being pulled by external forces, etc. For example, a passenger standing on a bus with his hand on the lever, suddenly encountering an emergency brake, may cause rotator cuff injury. Chronic rotator cuff injuries are common in elderly people over 60 years old; in addition, they are also more common in people who are engaged in long-term sports such as tennis, baseball, badminton, swimming and other sports that require the upper limbs to be raised above the head. Rotator cuff injuries are mainly characterized by pain during shoulder abduction and lifting, and in severe cases, the affected shoulder needs the help of the opposite hand to complete the lifting action because of weakness. If patients with rotator cuff injuries are allowed to perform functional exercises such as “wall climbing” or artificially pulling, the tears in the rotator cuff may increase and aggravate the injury. It is recommended that patients with shoulder pain seek treatment from a specialist shoulder surgeon or orthopedic sports medicine physician after a clear diagnosis. Some patients with shoulder pain can be relieved by oral anti-inflammatory and pain relieving medications and local closure therapy. For conditions where conservative treatment is ineffective, joint stiffness is difficult to relieve, and shoulder weakness is dysfunctional, shoulder arthroscopy and surgical treatment may be considered. Common indications for shoulder arthroscopy are as follows: 1. glenohumeral instability (including “habitual shoulder dislocation”, etc.) 2. biceps tendon injury 3. shoulder stiffness (including “frozen shoulder”, etc.) 4. glenohumeral arthritis 5. periarthritic cyst 6. Shoulder joint infection 7.impingement syndrome 8. partial and full rotator cuff tear 9. acromioclavicular joint disease 10. calcific tendonitis 11. partial shoulder fracture Contraindications to shoulder arthroscopy: infection around the incision or systemic condition, unable to tolerate surgery and anesthesia.