This is due to the anatomical and physiological characteristics of the shoulder joint, such as a large humeral head, a shallow and small joint pelvis, a loose joint capsule, weak tissues below the front of the joint, a large range of joint movement, and more opportunities for external forces. Shoulder dislocation occurs mostly in young adults and more often in men. Symptoms and signs 1. Swelling of the injured shoulder, pain, and limitation of active and passive activities. 2. The affected limb is flexibly fixed in a mild external booth, often with the affected arm supported by the healthy hand, with the head and trunk tilted to the affected side. The shoulder deltoid is collapsed, with a square shoulder deformity. The displaced humeral head can be palpated in the axilla, under the rostral process or under the clavicle, and the joint pelvis is empty. 4. Positive shoulder hitch test. When the affected hand leans on the chest, the palm of the hand cannot hitch on the opposite shoulder. Treatment 1.Manipulation reset The dislocation should be reset as soon as possible, and appropriate anesthesia (brachial plexus anesthesia or general anesthesia) should be selected to relax the muscles and make the reset painless. Elderly people or those with weak muscles can also be performed under analgesic (such as 75-100 mg of dulcolax). Habitual dislocation can be performed without anesthesia. The repositioning technique should be gentle, and rough techniques are prohibited to avoid additional injuries such as fractures or damage to nerves. The indications are: anterior shoulder dislocation with backward slippage of the long head of biceps tendon that hinders the repositioning of the shoulder joint, avulsion fracture of the greater tuberosity of the humerus, fracture fragment stuck between the humeral head and the articular pelvis that affects the repositioning, combined with fracture of the surgical neck of the humerus that cannot be repaired by manipulation, combined with fracture of the rostral process, acromion or glenoid of the shoulder joint with obvious displacement, combined with large axillary vascular injury. Vascular injury. 3. Treatment of old shoulder dislocation If the shoulder joint has not been repositioned for more than three weeks after dislocation, it is considered old dislocation. The joint cavity is filled with scar tissue, there are adhesions with the surrounding tissues, contracture of the surrounding muscles, formation of bone scabs or deformed healing in the case of combined fractures, all these pathological changes prevent the humeral head from resetting. Treatment of old shoulder dislocation: If the dislocation is within three months, the patient is young and strong, the dislocated joint still has a certain range of motion, and there is no osteoporosis and intra- or extra-articular ossification on the X-ray film, a trial of manual repositioning can be performed. Before resetting, the affected ulnar hawkbone can be traction for 1 to 2 weeks; if the dislocation time is short and the joint activity is light, no traction can be made. The resetting should be performed under general anesthesia, followed by shoulder massage and gentle rocking activities to release the adhesions and relieve muscle spasm to facilitate resetting. The operation of resetting is done by traction and massage or foot stirrups, and the treatment after resetting is the same as that of fresh dislocation. It must be noted that the operation must not be rough to avoid fracture and axillary neurovascular injury. If the manual repositioning fails, or if the dislocation has exceeded three months, surgical repositioning can be considered for young and strong-aged casualties. If the joint surface of the humeral head is found to be severely damaged, then shoulder fusion or artificial joint replacement should be considered. After shoulder joint repositioning surgery, the activity function is often unsatisfactory. For elderly patients, surgical treatment is not advisable and patients are encouraged to strengthen shoulder activities. 4.Treatment of habitual anterior shoulder dislocation Habitual anterior shoulder dislocation is mostly seen in young adults. The reason for this is that it is generally believed that the injury was caused after the first traumatic dislocation, and although it was reset, it did not receive proper and effective fixation and rest. The joint becomes lax because the joint capsule is torn or avulsed and the cartilage glenoid lip and glenoid rim are not well repaired, and the posterior lateral humeral head depression fracture becomes equal to the pathological changes. Subsequently, dislocation may occur repeatedly under slight external forces or during certain movements, such as abduction and external rotation and posterior extension of the upper extremity. The diagnosis of habitual shoulder dislocation is relatively easy. During X-ray examination, in addition to taking anteroposterior plain films of the shoulder, anteroposterior X-rays of the upper arm in the 60-70° internal rotation position should be taken, which can clearly show the posterior humeral head defect. For habitual shoulder dislocation, arthroscopic surgery is recommended if the dislocation is frequent. The aim is to strengthen the anterior wall of the joint capsule, prevent excessive external rotation and abduction, and stabilize the joint to avoid further dislocation. There are many surgical methods, the more commonly used ones are overlapping suture of the subscapularis capsule and external displacement of the subscapularis stop.