frozen shoulder
Adhesive capsulitis of the shoulder, also known as frozen shoulder, is a condition characterized by thickening and contraction of the shoulder joint capsule and surrounding synovium. Adhesive capsulitis can rarely affect other sites such as the ankle .
Epidemiology
The incidence in the general population is thought to be 3-5%. Adhesive capsulitis typically affects women in their 5 to 6 decades, although patients with co-morbidities such as diabetes mellitus may develop the condition at earlier ages. The incidence in patients with diabetes is reported to be 2 to 4 times higher than in the general population.
Clinical presentation
Adhesive capsulitis presentation can be broken into three distinct stages:
- freezing: painful stage
- patients may not present during this stage because they think that eventually, the pain will resolve if self-treated
- as the symptoms progress, pain worsens and both active and passive range of motion (ROM) becomes more restricted
- this can eventually result in the patient seeking medical consultation
- typically lasts between 3 and 9 months and is characterized by acute synovitis of the glenohumeral joint
- frozen: transitional stage
- most patients will progress to the second stage
- during this stage, shoulder pain does not necessarily worsen
- because of pain at the end of the range of motion, arm movement may be limited, causing muscular disuse
- can last between 4 to 12 months
- the common capsular pattern of limitation has historically been described as diminishing motions with external shoulder rotation being the most limited, followed closely by shoulder flexion, and internal rotation
- a point is eventually reached in the frozen stage where pain does not occur at the end of the range of motion
- thawing stage
- begins when the range of motion starts to improve
- lasts anywhere from 12 to 42 months and is defined by a gradual return of shoulder mobility
Pathology
Adhesive capsulitis is divided into two main types:
- primary or idiopathic
- absence of preceding trauma
- secondary
- major or minor repetitive trauma
- shoulder or thoracic surgery
- endocrine, e.g. diabetes, hyperthyroidism
- rheumatological conditions
Radiographic features
Fluoroscopy
Described features on fluoroscopic arthrography include:
- limited injectable fluid capacity of the glenohumeral joint
- small dependent axillary fold
- small subscapularis bursa
- irregularity of the anterior capsular insertion at the anatomic neck of the humerus
- lymphatic filling may be present
Ultrasound
- limitation of movement of the supraspinatus is considered a sensitive feature
- limited external rotation, identified when positioning for subscapularis tendon assessment
- thickened coracohumeral ligament (CHL) can be suggestive
- echogenic material around the long head of biceps at rotator interval
- increased vascularity of long head of biceps at rotator interval
MRI/MR arthrography
- normal inferior glenohumeral ligament measures <4 mm and is best seen on coronal oblique images at the mid glenoid level; in adhesive capsulitis, the axillary recess may show thickening ≥1.3 cm
- joint capsule thickening
- anterior capsule thickness >3.5 mm and abnormal hyperintensity
- abnormal soft tissue thickening within the rotator interval with signal alteration
- abnormal soft tissue encasing the biceps anchor
- variable enhancement of the capsule and synovium within the axillary recess and rotator interval
Other MR arthrography features include:
- thickening of the coracohumeral ligament (CHL)
- subcoracoid triangle sign
Chronic frozen shoulder may show low T2 signal and pericapsular scarring .
Treatment and prognosis
Adhesive capsulitis is typically a self-limiting disease that improves over 1-2 years. Treatment options include:
- physiotherapy
- corticosteroid injections
- glenohumeral hydrodilatation
- closed manipulation under anesthesia
- arthroscopic capsular release with lysis of adhesions
Siehe auch:
- Tendinosis calcarea der Rotatorenmanschette
- calcific periarthritis
- periarthritis
- sub-coracoid triangle sign