Shoulder pain is common among people of all ages, and people tend to generalize “shoulder pain” as “frozen shoulder”, causing confusion and increasing the pain of patients in treatment. Therefore, it is important to fully understand the etiology and pathological mechanisms of various “shoulder pains” in order to “target” them. Frozen shoulder The commonly known “frozen shoulder” is medically known as frozen shoulder. Its clinical incidence is not high, accounting for 10-15% of shoulder pain. Freezing shoulder is a self-limiting disease of unknown etiology that occurs between the ages of 40 and 50. Its etiology is not well understood, but some studies suggest that it is associated with autoimmune diseases and infections, and a history of diabetes is also a high risk factor. Its pathology is characterized by severe adhesions of the joint capsule within the shoulder joint. The symptoms are progressive limitation of shoulder motion without cause, especially limitation of external rotation, and pain in the shoulder joint, which can affect sleep in severe cases. The pain and limitation of motion peak 3-6 months after the onset of the disease, after which the symptoms gradually resolve, and without treatment most patients experience complete resolution of symptoms about 1 year after the onset of the disease, but may have varying degrees of residual shoulder dysfunction. Sometimes the onset of symptoms in one shoulder joint may be followed by an attack in the other shoulder joint some time later. The diagnosis of frozen shoulder is a diagnosis of exclusion, which means that all diseases that may cause shoulder pain and limited movement, such as rotator cuff injury, post-traumatic adhesions, and osteoarthritis of the shoulder joint, should be excluded before making a diagnosis. Because of the self-limiting nature of frozen shoulder, most of them do not require surgery, but they must undergo strict and active functional exercises under the guidance of a doctor. The aim is to maintain a certain degree of shoulder mobility during the period of restricted shoulder movement, so that normal shoulder movement can be maintained even after the joint adhesions recover on their own. For a small number of patients who cannot relieve themselves, surgical treatment is required. With the development of arthroscopic surgery in recent years, we can perform arthroscopic release of the joint capsule, and supplement it with pushing and releasing under anesthesia, which can obtain satisfactory results. Subacromial impingement syndrome Subacromial impingement syndrome is the most common cause of shoulder pain and accounts for the first place in shoulder pain. When the subacromial space is narrowed in the pathological state, the rotator cuff is compressed by the acromion after the upper arm is raised, causing an impingement between the structures, resulting in injury to the bursa and supraspinatus tendon. The pain may be caused by tendonitis of the bursa or rotator cuff itself, or it may be caused by a partial rotator cuff tear. The main symptoms are pain in the shoulder, pain at night, waking up in pain, and disruption of sleep; difficulty in pointing out a clear site of pain; and difficulty in raising the arm over the head. Diagnosis of impingement of the rotator cuff relies on symptoms and signs. Patients need to be photographed. Supraspinatus outlet position can sometimes be seen with small bone spurs at the anterior border of the acromion. MRI can reveal an effusion or bursitis or a partial tear of the rotator cuff. Rotator cuff calcification is often combined with acromioclavicular impingement and rotator cuff injury. Treatment of acromioclavicular impingement and rotator cuff injury should be tailored to the patient’s specific condition. If the patient does not have an acute onset and has a short history, and there are no signs of a large subacromial spur or rotator cuff tear on radiographs and MRI, conservative treatment, including subacromial seal injections and physical therapy, may be considered first. If conservative treatment is ineffective or if the patient has a sudden progression of shoulder pain and weakness within a short period of time and there is clear evidence of tendon tear on imaging, then surgery is recommended. Currently, the main treatment modality is arthroscopic shoulder surgery with subacromial decompression and anterior acromioplasty. The treatment of impingement of the acromion is accompanied by treatment of concomitant conditions such as acromioclavicular arthritis, biceps tendonitis or partial rotator cuff tears. Shoulder arthroscopy is minimally invasive and has a low incidence of intraoperative and postoperative comorbidities. During the arthroscopic procedure, 2-3 puncture holes are made. Each hole is about 5 mm and a fiber-optic camera system is used to examine the shoulder joint through these small holes, and small delicate instruments can be used to perform surgical operations within the shoulder joint for treatment purposes. Rotator Cuff Injuries Rotator cuff tears are a common cause of shoulder pain and mobility problems in adults. The rotator cuff is made up of four muscles and their accessory tendons. They form the rotator cuff that wraps around the head of the humerus. These four muscles are the supraspinatus, infraspinatus, subscapularis and teres minor, which start at the scapula and together form a tendinous unit that then ends at the greater or lesser tuberosity of the humerus. The rotator cuff serves to lift and rotate the upper arm and stabilize the humeral head within the shoulder joint. Most tears occur in the supraspinatus, but other muscles are also involved. Symptoms of rotator cuff tears can be acute or progressive in onset. Acute pain usually occurs after an acute trauma, such as an overhead movement or a fall (e.g., traction, fall, impact). Progressive injuries are more common and can be caused by repetitive overhead motion or wear or degeneration of the tendon, and the patient will feel pain radiating from the shoulder all the way to the arm. At first the pain is mild and only occurs during overhead movements. Over time, the patient may experience rest pain, or constant shoulder pain, especially with overhead movements, increased pain and weakness; a rattling sound may be heard in the joint during shoulder movement; joint mobility may be limited; nighttime pain, especially inability to sleep on the affected side; it may be aggravated or triggered by a cause; other symptoms include shoulder stiffness and limited movement. Patients may have difficulty combing their hair and tying the buckle behind their back. In tears that occur after an injury, there will be a sudden onset of pain, and acute weakness in the shoulder. The diagnosis of rotator cuff tears is based on the patient’s symptoms, signs, x-rays, and MRI, and treatment of rotator cuff tears can be achieved through minimally invasive arthroscopic techniques to achieve early repair, reduce pain, and prevent future degenerative rotator cuff injuries. As the quality of life in China continues to improve, participation in sports and exercise has become an integral part of daily life. Shoulder dislocation is a common injury, mostly in young people, and the incidence of recurrent dislocation is high. Habitual shoulder dislocations are common after trauma or contact sports such as basketball, soccer and wrestling. The shoulder joint is one of the more unique joints in the human body and is the most mobile of all the joints in the body. Unlike other joints, the stability of the shoulder joint relies heavily on the balance of tension in the soft tissues around the shoulder joint, including muscles and ligaments. Recurrent shoulder dislocation can seriously affect the function of the shoulder joint, as the dislocation causes tearing of the shoulder capsule and ligaments, and the stability of the shoulder joint is damaged. According to clinical experience, conservative treatment for recurrent shoulder dislocation is less effective, especially in young patients, so surgery is usually needed to reconstruct the torn capsule and ligaments to repair the stable structure of the shoulder joint. In recent years, with the continuous development of arthroscopic techniques and instruments, the application of suture anchors through arthroscopic techniques for the treatment of habitual shoulder dislocations has led to very satisfactory treatment results. Arthroscopic shoulder surgery has the advantages of less trauma, less patient pain, and faster functional recovery. The surgery that used to require an 8-10 cm incision can be solved by arthroscopic surgery with only 2-3 small incisions of less than 1 cm. The above-mentioned diseases are common clinical causes of shoulder pain. For a definitive diagnosis and standardized treatment, you need to see an outpatient clinic specializing in the shoulder joint and undergo surgery using minimally invasive arthroscopic techniques. Post-surgery, progressive joint rehabilitation is also required to achieve ideal joint function and improve quality of life and movement.