We all know that the shoulder is the most flexible joint, from the usual grasp of the back to the throwing reflects its value. However, this also brings with it a decrease in shoulder joint stability and impingement of the soft tissues and bone in the shoulder during exercise, resulting in shoulder pain. Some people have pain during exercise, others have persistent pain throughout the day and worse at night. All of these require a clear diagnosis and accurate treatment.
In China, shoulder pain is often seen as “frozen shoulder”, which is scientifically known as “adhesive capsular periarthritis” and is associated with immune system disorders and diabetes. The general public has little understanding of the causes and pathological mechanisms of “shoulder pain”, and once it occurs, they think it is “frozen shoulder”. Once shoulder pain occurs, it is considered as “frozen shoulder”, and “frozen shoulder” becomes a “scapegoat” diagnosis for other causes of shoulder pain, and there is even a clear treatment method D “climbing the wall”! The effect can be imagined. Therefore, shoulder pain patients need to understand the common causes, seek medical attention as early as possible, and get as much information about your shoulder pain and treatment options from your doctor.
I. Anatomy of the shoulder joint
Figure 1: Schematic diagram of the main anatomical structures of the shoulder joint that are associated with shoulder pain.
The shoulder joint is made up of three main bones: the humerus, scapula and clavicle. The humeral head matches the scapular glenoid, and the rotator cuff wraps around the humeral head to keep it in the central part of the scapular glenoid. The rotator cuff includes four muscles, supraspinatus, infraspinatus, subscapularis, and teres minor, which start at the scapula and end at the greater trochanter of the humerus. In addition, the long head tendon of the biceps muscle penetrates the inter-nodal sulcus and runs between the supraspinatus tendon and the subscapularis tendon. The acromion, rostro-humeral ligament, rostral process and subacromial bursa are visible above the rotator cuff.
II. Causes of shoulder pain
The main causes of shoulder pain are divided into four categories.
1.Tendonitis (bursitis or tendonitis) and tendon tears
2. Shoulder joint instability
3.Arthritis
4.Fracture
Other less common causes of shoulder pain include: tumors, infections and nerve-related diseases.
The spectrum of common diseases of shoulder pain is as follows.
1.Shoulder factors.
(1) Bone: tumors and shoulder fractures;
(2) glenohumeral joint: joint dislocation, laxity, adhesive capsular periarthritis, osteoarthritis, joint rat, rheumatoid arthritis, synovitis, subacromial impingement syndrome, joint instability, hill-sachs disease, Bankart injury, SLAP injury;
(3) Acromioclavicular joint: injury, degeneration;
(4) Muscle and tendon: rotator cuff tendonitis or rupture, biceps tendonitis or tear, rotator cuff and surrounding muscles injury, and subacromial and subscapular bursitis, etc;
2.Extra-shoulder factors.
(1) Commonly, there are cholecystitis, myocardial infarction, stroke;
(2) Nerve and vascular factors: cervical spondylosis, quadrilateral foramen syndrome, injury or compression of the long thoracic nerve, suprascapular nerve, paracentral nerve, thoracic outlet syndrome, etc.
Bursitis
Bursae are fluid-containing pouches that can form in any part of the body where there is friction, and bursae act as padding to reduce friction. There are nearly 10 bursae in the shoulder, and the most common lesion is the subacromial bursa, which is located just below the acromion and above the rotator cuff. Excessive shoulder motion and friction cause inflammation and swelling of the subacromial bursa (Figure 2). Subacromial bursitis is often associated with supraspinatus tendonitis and can induce swelling and aseptic inflammation in other tissues of the shoulder, producing pain. Shoulder pain affects daily life, such as pike head and dressing, and in severe symptoms, there is nocturnal pain.
Tendonitis
The four tendons of the rotator cuff muscle and the long head tendon of the biceps are often affected and tendonitis occurs. The supraspinatus tendon is located above the head of the humerus and is the most vulnerable to injury. Tendonitis is associated with natural degeneration of the tendon, chronic wear and tear, and trauma.
Tendonitis is divided into two categories.
1, acute tendonitis: throwing athletes have done too much throwing training, too much overhead movements in sports or work, such as swimming, wall cleaners, often occur acute tendonitis ;
2, chronic tendonitis: associated with tendon degeneration and repeated wear and tear with age can occur tendon tears.
Tendon Tears
Splitting or tearing of the rotator cuff tendon occurs as a result of sudden acute injury and degeneration (aging, long-term overapplication and wear) (Figure 4). The tear may be partial or complete, mostly complete, and the tendon is mostly torn from the bone stop. The supraspinatus tendon and the long head of the biceps tendon are most frequently involved.
Shoulder impingement syndrome
Impingement syndrome refers to the soft tissues within the subacromial space that impinges on the rostroscapular arch (consisting of the acromion, rostroscapular ligament, and rostral process see Figure 4) above the shoulder joint during supination. Repeated impingement of the subacromial bursa, rotator cuff tendons (especially the supraspinatus tendon) and the long head of the biceps tendon in the subacromial space induces bursitis and tendonitis, causing pain and limited shoulder movement. As the symptoms persist, severe impingement of the rotator cuff tendon ruptures the rotator cuff tendon.
The subacromial impingement syndrome is a common cause of subacromial impingement syndrome due to hyperplasia of the acromion (Figure 5), acromioclavicular joint hyperplasia, and instability of the shoulder joint.
Tendonitis induced by subacromial impingement syndrome occurs in three stages.
In the first stage, tendon edema and hemorrhage ;
Phase II, fibrosis and tendonitis ;
In the third stage, the acromion spur, tendon degeneration or tendon rupture. It should be noted that when the tendon develops to stage II, the pathological changes in the tendon are irreversible, so conservative treatment for 3 to 6 months is ineffective and surgery is recommended.
Shoulder instability
Shoulder instability refers to symptomatic displacement between the humeral head and the shoulder pelvis during activity. The humeral head extends beyond the glenoid during shoulder motion (Figure 6), which is associated with trauma and overuse. The humeral head may be partially or completely dislocated from the glenoid. Once the ligaments, tendons and muscles around the shoulder joint are relaxed or torn, this subluxation or dislocation can occur repeatedly and pain and instability occurs when the shoulder joint is lifted or exercised. In addition, humeral head and shoulder glenoid defects directly contribute to shoulder instability. The result of repeated subluxations or dislocations is osteoarthritis of the shoulder joint.
Shoulder arthritis
Shoulder pain can also be caused by shoulder osteoarthritis, which has several causes. Shoulder osteoarthritis refers to the wear and tear of the articular cartilage (Figure 7), which develops slowly and is associated with trauma, sports injuries and prolonged overuse at work. The symptoms are swelling and stiffness, and the patient is often restricted in movement due to pain, and this leads to progressive tension and stiffness of the soft tissues surrounding the joint. Other shoulder arthritis is associated with rotator cuff tears, infections, and rheumatoid arthritis.
Fractures
Fractures of the shoulder mainly involve the humerus, clavicle and scapula. These fractures cause severe pain, swelling and bruising.
III. Examination by a physician
Acute injuries cause severe pain, seek medical attention as early as possible. If the pain is not severe, you can rest for a few days and observe yourself. If the symptoms persist, you will need to see a doctor. In order to be able to determine the cause of your shoulder pain and treatment options, your doctor will need to perform a thorough examination and evaluation.
Medical History
The first step in the evaluation is to take a medical history. The doctor asks when and how the shoulder pain occurred, if you have had similar conditions in the past, and how you were treated after the onset. Other questions are to learn about your general health and look for possible related causes. Most shoulder pain is aggravated or relieved by specific movements, and knowledge of the history is valuable in finding the source of the shoulder pain, the
Physical examination
In order to find the cause of shoulder pain, a thorough physical examination is necessary to observe range of motion and muscle strength, to identify abnormalities, swelling, deformities or decreased muscle strength, to carefully examine the painful area, various provocation tests, muscle strength tests are complex, especially in patients with shoulder stiffness and significantly limited motion, and it is difficult to identify the initial cause through physical examination alone.
Examination
In order to determine the cause of pain and related problems, the doctor needs to perform special tests.
1. X-rays: They show shoulder fractures, bone changes and abnormal bone structure. The shoulder joint radiographs are demanding and special position radiographs are meaningful for diagnosis.
2.MRI: It shows the soft tissues better and is especially helpful for the ligaments, tendons, muscles, synovium and severe articular cartilage of the shoulder joint.
3.Enhanced MRI: Better contrast of the above soft tissue injuries.
4.CT: It can show the bone structure of the shoulder joint more clearly, and the 3D image reconstruction can show the changes of bone morphology and structure better.
5.Electromyography: To evaluate the nerve function.
6.”B” ultrasound: It has high diagnostic value for rotator cuff tendinopathy and shoulder bursa, especially for body non-invasive.
7.Arthroscopic exploration: Minimally invasive surgical procedure that can show soft tissue injuries that cannot be detected by physical examination, x-ray, ultrasound, and MRI. The relevant problems are evaluated under direct vision.
IV. Treatment
1.Change of movement
Treatment includes rest, change of movement, and physical therapy to improve the muscle strength and flexibility of the shoulder muscles. Routine solutions to hair cases, such as avoiding excessive force and over application, all of which are aimed at preventing shoulder pain aggravation.
2.Medication
Medications are mainly to reduce sterile inflammation and pain and will be taken under the guidance of a physician. Doctors may also recommend local closure to reduce pain. Shoulder closure is more demanding than other parts of the body and accuracy is crucial, and closure treatment should preferably be given no more than 3 times a year.
3.Surgery
The vast majority of patients with shoulder pain can achieve results with rest, changes in exercise, physical therapy, medication and physical therapy, but the treatment period is longer.
For some definite shoulder problems, such as recurrent shoulder dislocation, glenoid labral injury, a part of patients with rotator cuff tears cannot benefit from the above conservative treatment. In order to be able to resolve these shoulder pains, surgery is also necessary, and it is better to do it sooner rather than later. Surgery can be done under total arthroscopy, arthroscopy-assisted small incision surgery, and in some cases, incisional reconstruction is required, and in severe cases, shoulder arthroplasty is needed.