“Many patients ask me what rotator cuff is and why my rotator cuff is in trouble. Borrowing from the popular “Legend of the Sheep and the Moon”, I wrote this “Sheep and the Moon” version of the rotator cuff, so that patients can more easily understand the pathogenesis of rotator cuff disease. Because only by understanding this disease, can we better cooperate with the doctor’s treatment and solve this disease. “Sheep version” of rotator cuff injury and acromioclavicular impingement The rotator cuff is four sisters: supraspinatus, infraspinatus, teres minor and subscapularis, they play an important role in the stability and function of the shoulder joint. The supraspinatus is located directly above the humeral head and is mainly responsible for the shoulder joint’s elevation and abduction, which is the most important function, and she is the main character Mi Yue; the infraspinatus, the teres minor is responsible for external rotation, and the subscapularis is responsible for internal rotation, and they are Mi Shu and Wei Meiren and the like; these four sisters are attached to the large and small tubercle at the proximal end of the humerus, and tightly encircle the king of their Qin—humeral head; and the rotator cuff is located in their area, and it is the only one of them that can be used in the shoulder joint. These four sisters are attached to the large and small nodes of the proximal humerus, which tightly enclose the head of the humerus, the king of Qin; and above them, there is a bony protrusion of the scapula that looks like a roof, the acromion, which is the warm man’s rest, and whose dominant rostral-shoulder arch shields the four sisters of the rotator cuff every day. The humeral head is located in the center of the shoulder joint, like the “King of Qin”; the rotator cuff “Mi Yue” and so on wrapped around the humeral head; the acromion is like a roof for the rotator cuff to protect from the wind and rain, like “Zi Xie”. Under normal circumstances, there is enough space in the gap under the acromion, the contraction of rotator cuff muscles drive the humeral head to do forward flexion, abduction, internal and external rotation and other directional movements, the rostrum shoulder arch in the periphery, the rotator cuff in the middle of the rotational center and the rotational center of the humerus head as one, forming a family of shoulder joints centered around the King of Qin. But this rotator cuff is a weak point, young and flexible tendon, old degeneration, slowly lose elasticity, coupled with the lack of blood supply at the end of the tendon, repeated exercise after the strain, or pulling, falling and other traumas can make it tear, the movement process can not be very good to guide the humeral head of the movement of the humerus, humerus head produced instability in the shoulder joint lifting abduction and other movements of the humerus proximal end of the humerus will impinge on the shoulder peak. The rotator cuff is soft, sometimes, trauma or strain injury can not lead to fracture, but will make the rotator cuff tear, tear is too big humeral head without rotator cuff stabilization, it will be moved up, close to the acromion, so it is also easy to fight with the acromion, secondary to the acromion impingement syndrome. Sometimes, although the rotator cuff is still good, but the acromion osteophytes develop bone spurs, which can also cause impingement, leading to impingement of the acromion syndrome. In some patients, the anterior part of the rotator cuff may become hooked, i.e., hooked acromion, warm man’s rest becomes hard man’s Zhai Li, bone proliferation, synovial membrane swelling, from harmony to impingement, from smooth to obscure, the rotator cuff is sandwiched between the acromion and the head of the humerus, and becomes a victim of hard man’s fights, and already fatigued and damaged rotator cuff tendon fibers because of recurrent impingement add more frost to injury, and the fissure is getting bigger and bigger, which leads to rotator cuff injury …… Hooked acromion or acromion with bone spurs and humeral head in the shoulder joint abduction impingement will trigger acromion impingement syndrome (subacromial bursitis), in the long run, sandwiched in the middle of the soft girl rotator cuff become a victim of the fight between the acromion and the humeral head, rotator cuff injuries Rotator cuff and the rotator cuff, when it is good, as the ZiXie and Mi Yueqing me. When it’s good, it’s like Zi Xie and Mi Yue having a good time. Once rotator cuff impingement syndrome occurs, it is like Zai Xie and Mi Yue hurting each other. Therefore, impingement syndrome and rotator cuff injuries often occur together in clinical practice. Misdiagnosed as “frozen shoulder” will be more and more serious However, the patient is often not aware of these, she or he may be a housewife (husband), teachers, white-collar workers, surgeons, or athletes, I do not know which day the shoulder began to ache, thought that a few days of rest will be good, but who knows the pain is getting heavier and heavier, the beginning of the arm is only lifted up and adduction pain, and then when you sleep, the pain will also be more and more severe. At first, the pain was only when the arm was lifted and adducted, and then when sleeping, it was also painful, and no matter how to adjust the sleeping position, the pain in the shoulder was intolerable, seriously affecting sleep, and often woke up late at night with pain and stayed up alone until dawn. …… had seen a few doctors, and it was considered to be “frozen shoulder”. Listened to the advice of neighbors to exercise, to practice climbing walls, practice rollerblading, desperately practicing shoulder lifting, but did not expect the situation is getting worse. I remember in 2007 from the United States to learn shoulder arthroscopy technology back to China, whenever and patients talk about rotator cuff injuries, the other side often look puzzled, I have a “frozen shoulder”! What is rotator cuff? I’ve never had an injury, why would I have a rotator cuff injury? …… Therefore, acromioclavicular impingement and rotator cuff injuries are easily under-diagnosed and overlooked. How to differentiate from frozen shoulder The full name of acromioclavicular impingement is subacromial impingement syndrome, which is a condition in which the head of the humerus and the greater tuberosity repeatedly impinge on the anterior border of the acromion and subacromial structures when the shoulder joint is abducted, causing localized osteophytes, sclerosis, subacromial bursa, and rotator cuff tissues to be extruded, resulting in pain, weakness, and limitation of the shoulder’s movement. Once combined rotator cuff injuries tend to get progressively worse and cannot heal themselves. To put it bluntly, Zhai Li and the king of Qin two old fight, let Mi Yue sandwiched in the middle of the anger. Frozen shoulder” is a type of adhesive capsulitis that causes stiffness of the glenohumeral joint, to put it bluntly, the King of Qin (humeral head) was wrapped up too tightly by his harem and could not stretch, so it is also known as “frozen shoulder” or “frozen shoulder”, this problem is self-limiting. “This problem is self-limiting, and 50% of patients can be cured by conservative treatment in one to one and a half years. Therefore, if shoulder pain does not improve for more than one and a half years, most of them are not frozen shoulder but rotator cuff injury and acromioclavicular impingement. In addition to the factors of the disease process, there is also a clear difference between the two problems in the clinical manifestations, acromioclavicular impingement in the active abduction of the shoulder joint has a pain arc, that is, the shoulder abduction 60 ° ~ 120 ° range of obvious pain, and passive activities to reduce the pain, acromioclavicular impingement test: Neer’s sign, Hawkins’ sign is positive. When combined with rotator cuff injury, there will be a decrease in supraspinatus muscle strength, positive supraspinatus stress test, and pressure points in the area of the greater tuberosity. In contrast, frozen shoulder is mainly characterized by limited passive and active movements of the shoulder joint in all directions, especially the passive external rotation of the shoulder joint, and the pressure points are often in the anterior part of the shoulder joint and the lateral part of the rostral process. In addition, the X-ray of acromioclavicular impingement can show the bony cumbersome acromion of the acromion and the narrow gap between the acromion and the head of the humerus, which is a simple and effective diagnostic means. MRI scan can directly and clearly show the signs of rotator cuff tendon tear and the disappearance of the surrounding fat band, which can help to confirm the diagnosis. Imaging of frozen shoulder is often unremarkable. Arthrography can be helpful in the imaging diagnosis of frozen shoulder and often shows a significant reduction in the volume of the joint capsule. Acromioclavicular impingement and rotator cuff injuries should be treated aggressively, and delayed treatment may result in disability Acromioclavicular impingement and rotator cuff injuries need to be diagnosed and treated at an early stage. Early non-surgical treatment can be used for mild injury, aiming at eliminating edema and congestion and relieving local pain, which can be treated by physical therapy, changing the way of exercise, non-steroidal anti-inflammatory drugs and local closed treatment, etc. It should be emphasized that repeated abduction and lifting of shoulder should be avoided in the early stage of the functional exercise, such as climbing the wall, rollerblading, freestyle swimming, badminton, etc., which are easy to lead to repeated impingement of the humeral head and the acromion, aggravating the condition. These sports will easily lead to repeated impingement of the humeral head and the acromion, which will aggravate the condition. If conservative treatment fails to improve the discomfort of the shoulder, hospitalization for subacromial decompression under shoulder arthroscopy should be performed as soon as possible to avoid the development or aggravation of rotator cuff injury. Moderate to severe rotator cuff injury or partial tear of rotator cuff that cannot be relieved for a long period of time will lead to muscle atrophy, stiffness of the shoulder joint, long-term pain can also lead to depression and neurasthenia. Arthroscopic minimally invasive rotator cuff repair is needed as soon as possible. The torn rotator cuff is re-secured to the bone surface, allowing Mi Yue to break the mirror with the King of Qin in order for the rotator cuff to heal. Minimally invasive surgery allows the rotator cuff and humeral head to be broken and restored to the stability and function of the shoulder joint, as well as removing the acromioclavicular bone spur and relieving pain. After surgery and systematic rehabilitation, patients are mostly able to regain function. Otherwise, once a huge irreparable rotator cuff tear is formed, it will lead to the disability of the affected limb and osteoarthritis of the shoulder joint, and many patients can only receive artificial joint replacement eventually to alleviate their condition. In summary, the elderly over 40 years of age, or young people repeatedly engaged in over-the-top sports or after trauma, shoulder pain, especially hand over head pain aggravated, accompanied by a feeling of weakness, first of all to suspect rotator cuff injury, need to be early to find sports injury specialists to see a doctor.