First of all, shoulder pain is not always frozen shoulder. The folk term frozen shoulder is a rather general concept that refers to all inflammation around the shoulder joint, while the common clinical shoulder pain is rotator cuff injury, which may be caused by impingement syndrome, or synovitis, or glenoid labral injury, etc. You need to go to a specialist in joint surgery for a clear diagnosis, as the treatment modalities are diametrically opposed. Here we are talking about the “authentic” frozen shoulder – the adhesive capsulitis. Treatment requires functional exercise, whereas other causes of shoulder pain may not. Histopathology of frozen shoulder: 1. Reduced joint cavity volume – normal arthrography can accommodate 15~18ml of fluid, but in cases of frozen shoulder, it is less than 10ml and most are less than 5~6ml. 2. MRI studies suggest that a joint capsule thickness of more than 4mm has 95% specificity and 70% sensitivity for the diagnosis of frozen shoulder. 3. The natural course of frozen shoulder 1. the painful phase 2. 5~9 months, manifesting as gradually increasing periapical pain. 2. 2.the siffening phase 4~12 months, characterized by pain relief and progressive reduction of shoulder mobility in all directions, with external rotation being the most obvious. 3.The thawing phase 5~26 months, mobility is gradually restored. 4.Frozen shoulder is self-limiting, without treatment, the entire course of the disease is 12~42 months, with an average of 30 months, and in about 60% of cases, the mobility of the affected shoulder is difficult to return to normal. Treatment: 1) Oral medications such as NSAID have limited efficacy; 2) Early local sealing and rehabilitation have good efficacy; 3) Calcitonin, such as MIGA, is used, but the principle of treatment is based on the theory that frozen shoulder is a reflex sympathetic dystrophy. 4. Joint expansion method, also known as hydroforming technique, is mainly aimed at reducing the volume of the joint cavity by intra-articular injection of 40-50 ml of fluid mixed with local anesthetics such as bupivacaine and lidocaine, and corticosteroids. Some scholars have reported good results in relieving pain and restoring joint mobility. 5.Treatment to restore joint mobility Functional exercise, has some effect, but must be persistent. The manual release under anesthesia , release has complications such as fracture, joint dislocation, rotator cuff injury, brachial plexus nerve injury, and soft tissue injury around the joint. Therefore, this treatment needs to be used with caution.