(A) Overview The shoulder joint has a high incidence of injury and is second only to the knee among the major joints in the body. Currently, surgical treatment of most diseases can be accomplished arthroscopically. The surgical treatment of rotator cuff tears has a history of nearly 100 years, and the surgical approach has gone through three stages: incisional repair, arthroscopic-assisted small incision repair, and total arthroscopic repair. In the past 20 years, with the development of arthroscopic instruments and fixation devices and the continuous improvement of arthroscopic surgical techniques, arthroscopic surgery has achieved excellent results. In the last decade or so, arthroscopic dislocation correction has been gradually developed, and arthroscopic suturing of glenoid labral tears has been carried out. As long as the indications for surgery are strictly mastered and skilled arthroscopic techniques are available, the recurrence rate of arthroscopic treatment of dislocation is controlled at about 5%. Arthroscopic treatment of other disorders has also been gradually developed and matured. (B) Indications Shoulder arthroscopy is used to treat shoulder disorders such as rotator cuff tear, glenoid labral injury, subacromial impingement syndrome, freehands, synovitis, frozen shoulder (shoulder adhesions), shoulder instability, biceps tendonitis, infection and acromioclavicular arthritis, etc. (C) Contraindications Infected skin around the shoulder joint, severe joint stenosis, hematogenous infection and systemic conditions that make the surgery unacceptable are all contraindications. （Shoulder arthroscopy is usually performed under general anesthesia. A posterior incision is made to insert the arthroscope for investigation, and an anterior incision is made to insert the instruments for operation. Rotator cuff tears and glenoid labral injuries are closed with special instrumentation, and if necessary, the rotator cuff or glenoid labrum is sutured to the bone using anchor staples. Free bodies are removed with a clamp, synovitis is removed with a planer, and in subacromial impingement syndrome, the bursa is removed and the impinging bone tissue is removed with a grinding head. Manual pushing is also required during the frozen shoulder surgery. Because the surgery is less invasive, postoperative protection of the affected limb with a triangular scarf is sufficient. In special cases, an abduction brace is required to fix the shoulder joint. (v) Complications The surgery may damage the nerve, cartilage, rotator cuff and shoulder pelvis bone, but the incidence is very low. In rare cases, fractures of the acromion or clavicle may occur. Postoperative infection and blood accumulation in the joint swelling occasionally occur. With careful preoperative evaluation and intraoperative caution, complications can be reduced. (vi) Postoperative rehabilitation Different progressions of rehabilitation exercises will be used depending on the degree of injury and the size of the trauma of the operation. The purpose of rehabilitation exercises is to obtain normal joint function as soon as possible under the premise of ensuring good healing of the repaired tissue. The exercises will mainly focus on flexion and extension, rotation function and muscle strength. Grip strength and wrist and elbow flexion and extension exercises are started immediately after recovery from anesthesia, muscle contraction training is started on the first postoperative day, and flexion and extension exercises are started 3~5 days after surgery. The time to start rotational function exercises varies depending on the condition and is decided by the surgeon and rehabilitation physician. Eventually, normal activities and sports will be resumed gradually under the guidance of the surgeon.