There was a time when almost all shoulder pain was labeled as frozen shoulder. In fact, with the continuous research on shoulder disorders, medical science now recognizes that frozen shoulder is a specific shoulder disorder. It is caused by chronic inflammation and fibrosis of the soft tissues surrounding the shoulder joint, resulting in pain and impaired function of the shoulder joint, eventually leading to stiffness and limited movement of the shoulder joint in all directions and in multiple planes, and slowly appearing after a suspicious precipitating event (minor trauma, cold, overexertion, etc.).
The American Academy of Shoulder and Elbow Surgeons defines it as a group of adhesive capsulitis causing glenohumeral stiffness, manifested by pain around the shoulder joint, reduced active and passive motion in all directions of the shoulder joint, and no significant abnormalities on impact examination except for bone reduction. The “capsular ligament” in the diagram is the site of periarthritis.
The new view is that the most appropriate and correct name should be “contracture shoulder capsulitis”, the essence of which is the fibrosis and fibroplasia of the soft tissue of the joint capsule around the shoulder joint, leading to contracture of the joint capsule.
The frozen shoulder accounts for about 10-20% of shoulder pain.
The total incidence of frozen shoulder in the population is 2-5%, and the age of onset is mostly 40-60 years old, with an average age of 50 years old. The incidence is higher in people with diabetes, thyroid disease, and hypoadrenalism, and is slightly more common in women than men. The pathogenesis of the disease is still inconclusive, but why is the age of 50 a good age? The age of 50 is a watershed in the transformation of the body’s organs and tissues into old age, and the body is constantly repairing itself from degenerative damage. Primary frozen shoulder is very rare, and most of them are secondary frozen shoulder. The pathological changes of frozen shoulder include contracture and thickening of the capsular ligament, contracture and thickening of the rotator cuff space and rostro-humeral ligament, inflammatory edema of the biceps muscle, adhesions around the subscapularis tendon, and inflammation of the subacromial bursa.
Staging of frozen shoulder.
1.Condensation stage (early stage): the duration of symptoms in this stage is 2-9 months, the lesion is mainly located in the shoulder joint capsule, the main characteristic is the progressive pain of the shoulder joint is aggravated, the night pain is obvious, the range of motion of the shoulder joint is reduced compared to normal.
2. Freezing phase: After the coagulation phase, as the degree of lesion intensifies, it enters the freezing phase. The symptoms last for 4-12 months. The pain decreases during this period, but the shoulder joint movement is obviously limited, especially the shoulder joint external rotation is most obvious.
3.Thawing period: This period generally lasts 12-42 months, with an average of 30 months. The inflammation gradually subsides, the pain disappears, and the shoulder joint activity gradually recovers, which is called the thawing period. It should be noted that not all patients with frozen shoulder have a benign regression, and some of them have a long history of pain and shoulder dysfunction, which can become persistent frozen shoulder and seriously affect their quality of life.
Traditional view
1. The majority of patients can fully recover their shoulder joint mobility.
2.Most of the patients’ symptoms can disappear on their own.
3. The duration of the disease is about 18-24 months.
New view
1.39%-76% of patients have significant limitation of mobility
2.45% of patients have persistent pain symptoms
3.The average duration of the disease is about 30 months
4. 50% of patients still have limited mobility after 5-10 years of follow-up.
Clinical manifestations of frozen shoulder.
The main symptoms are pain around the shoulder joint and limitation of joint movement
1. Gradually increasing shoulder pain. The pain is usually located in the anterolateral shoulder, sometimes it can radiate to the elbow, hand and scapular area, but there is no sensory impairment. The pain worsens at night, affecting sleep, and it is afraid to lie on the affected side.
2. Continuous pain can cause muscle spasm and atrophy. There is pressure pain in the front and back of the shoulder and under the acromion and deltoid stops, and the pressure pain is most obvious in the long head of the biceps tendon. The pain increases when the upper arm is abducted, externally rotated (characteristic performance) and posteriorly extended.
3. Shoulder joint movement disorder. In the early stage, shoulder joint movement is only mildly affected by internal and external rotation. The scapula should be fixed and compared bilaterally during the examination. In late stage, the upper arm is in internal rotation position, and the activity is limited in all directions, but the limitation of abduction and internal and external rotation is obvious, and the activity in anterior and posterior directions is generally present.
4. Late stage shoulder muscle atrophy is obvious, and sometimes blood circulation disorders in the upper extremity occur due to concurrent vasospasm, resulting in swelling, coldness and painful finger activities in the forearm and hand
Imaging manifestations of frozen shoulder.
1.X-ray may have no obvious abnormality, there may be extensive osteoporosis of the bones around the shoulder.
2.MRI: In general, there is no damage to the rotator cuff. If there is a combined rotator cuff injury, it is mostly a degenerative injury and a non-total tear, which can be seen as inflammatory thickening of the rotator cuff gap; in oblique coronal position, the axillary capsule is shrunken or disappeared; subacromial bursitis; in axial position, inflammatory edema of the long head of biceps tendon is seen, and a large amount of fluid accumulates in the biceps tendon groove.
3. Shoulder arthrography shows contraction of the shoulder capsule and disappearance of the lower fold of the capsule.
Clinical diagnosis of frozen shoulder.
1.Signs and symptoms: pain, limitation of active and passive shoulder joint activities
2. Physical examination: limited movement of the shoulder joint in all directions, scaphoid with displacement sign (+)
3. Imaging: x-ray shows extensive osteoporosis, bone scan reveals exuberant bone metabolism, MRI shows disappearance of the axillary capsule, hyperplasia and hypertrophy of the rotator cuff gap, and inflammatory edema of the long head tendon of the biceps tendon.
Treatment philosophy of frozen shoulder.
Conservative: frozen shoulder is self-limiting and should be treated conservatively
Radical: The course of frozen shoulder is unpredictable and should be treated surgically.
Rational: If the patient’s quality of life is significantly affected and there is no hope of improvement in a limited time, surgery should be used to terminate the course of the disease, regardless of whether and when it can be terminated on its own.
Principles of treatment for frozen shoulder.
Regardless of the stage of the disease, the patient should first receive 3 months of conservative treatment, including physical therapy, oral NSAIDS medication, and a single closed hormone injection, most of which will provide relief.
If the treatment is ineffective, the patient’s quality of life is significantly affected, the pain is severe, and the activity is severely limited and cannot take care of itself, surgery is recommended.
Conservative treatment.
1.Physiotherapy
2.Oral celecoxib, fotarine, meloxicam and other anti-inflammatory and pain-relieving drugs. Topical flurbiprofen gel cream, etc.
3.Functional rehabilitation exercise: the principles are all-directional, gentle and anti-violence, planned and persistent
Risks of manual release under anesthesia
1.Fracture around shoulder joint, hematoma formation, tear of glenoid lip of joint capsule, rotator cuff tear, cartilage injury, etc.
2.The treatment effect is good if the onset of the disease is more than 6 months, if the release is performed during the freezing period, it may aggravate the symptoms
Shoulder arthroscopic release
Patients with frozen shoulder may consider surgical release after 12 weeks of regular conservative treatment, if the symptoms do not improve significantly or if the patient still cannot tolerate the symptoms despite some improvement. Clinical studies have shown that arthroscopic release of the frozen shoulder, whether primary, diabetic-related or secondary, can be effective in patients with persistent frozen shoulder.
The procedure mainly includes release of the rotator cuff gap, 270 degree release of the subscapularis tendon, release of the anterior anterior inferior capsule, release of the posterior capsule, dissociation or fixation of the long head of the biceps tendon, decompression or molding of the acromion, and cleaning of the subacromial bursa. If combined with rotator cuff injury, the rotator cuff should be sutured.
1.Frozen shoulder is a common disease, the mechanism of occurrence is not clear.
2. It is probably self-deceiving that frozen shoulder can be relieved on its own.
3. Intra-articular and peri-articular hormone injections can improve and relieve most of the symptoms.
4. For persistent frozen shoulder, arthroscopic surgical release has a very reliable efficacy.