Adhesive Capsulitis [Frozen Shoulder}
The glenohumeral joint of the shoulder is a ball and socket joint in which the glenoid cavity of the scapula forms a socket for the humeral head.
. (See Figure 1). This arrangement allows a far greater range of motion than is seen at the hip -- with 120 degrees of unassisted flexion, the glenohumeral joint is the most mobile joint in the body. This motion, though, comes at the price of stability.
Figure 1: The “cup” of the hip and shoulder are outlined in red on these x-rays.
. As As seen, the hip joint is considerably more constrained by the bony anatomy than the shoulder. When the shoulder capsule becomes more rigid and bone-like, shoulder motion becomes more like that of the hip joint.
Stability of the glenohumeral joint is provided by the soft tissues. Dynamic (active) stability is a product of paired rotator cuff contraction, which tends to compress the humeral head into the glenoid cavity. The main source of static (passive) stability comes from the joint capsule (
figure Figure 2) and ligaments, with some static stability coming from the glenoid labrum, which effectively deepens the glenoid.
Figure 2: The capsule, outlined in blue, holds the humeral head against the glenoid, substantially augmenting the (meager) stability offered by the bony anatomy.
(Modified from Gray's Anatomy, Plate 327 https://commons.wikimedia.org/w/index.php?curid=108237)
Adhesive capsulitis is caused by contracture of the capsule and intra-articular adhesions which physically tether the joint capsule to surrounding bone and tissues and further limit motion.
Primary adhesive capsulitis is idiopathic.
adhesive Adhesive capsulitis is also associated with medical conditions (such as Diabetes Mellitusdiabetes mellitus, thyroid disease and stroke); medical interventions (such as prolonged immobilization, cardiac surgery and antiretroviral therapy for HIV); and injuries (such as rotator cuff tears or proximal humerus fractures). When there is an associated cause, the condition is designated as secondary adhesive capsulitis.
Clinically, isolated adhesive capsulitis has 3 distinct phases, namely: the painful phase, the stiff phase, and the resolution phases.
painful Painful (or “freezing”) Phase begins gradually, with no known precipitant. This phase, which lasts weeks to months, is characterized by diffuse, disabling pain that is worse at night.
On physical exam, patients with adhesive capsulitis have significantly reduced active and passive range of motion in two or more planes (see Figure 3 for normal ranges of motion). External rotation and abduction are the most commonly affected movements. Patients also have difficulty internally rotating, and report problems scratching their hand on their back or hooking their bra from behind.
Figure 3Figures 3A-C: The normal ranges of motion for forward elevation (3A), internal rotation (3B) and external rotation (3C) are shown, contrasted with the ranges seen in patients with adhesive capsulitis
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The critical finding of adhesive capsulitis is a loss of the end range of passive shoulder motion that is not limited by either pain or an intra-articular blockage. As such, the diagnosis is established precisely only with an examination under anesthesia, coupled by an arthroscopic and radiographic evaluation of the joint. A less precise, but nonetheless clinically useful, diagnosis can be made by relying on a completely cooperative patient’s report of subjective symptoms during the objective exam. (An inconsistent, irreproducible range of motion of examination precludes making the diagnosis of
Adhesive Capsulitisadhesive capsulitis: lost motion of an inconsistent degree is more likely due to pain, malingering or other forms of active limitation, and not capsular contracture.)
An intra-articular injection of an anesthetic can help eliminate the restrictions of motion imposed by pain.
Arthrography, in which the contracted joint is injected with contrast prior to imaging, can reliably diagnose capsular contracture: the normal shoulder accepts 20 ml of fluid without difficulty, but with adhesive capsulitis the shoulder usually holds less than 10 ml (Figure 4). Nonetheless, the degree of lost volume does not correlate perfectly with the degree of lost motion.
Figure 4: An arthrogram
, showing a reduced volume of contrast material within the shoulder joint. The red line outlines the border of the normal border of the capsule. Source credit: (Modified from Radiopaedia.org, https://radiopaedia.org/cases/7545">rID: 7545</a)
In primary adhesive capsulitis no specific laboratory findings are found, yet lab tests are commonly obtained once the diagnosis is made, to help identify a cause (e.g., diabetes).
Ultrasound can be used to rule out rotator cuff or bursal pathology. On ultrasound, thickening of the coracohumeral ligament and increase increased vascularity around the intraarticular portion of the biceps tendon may be seen with adhesive capsulitis.
Magnetic Resonance Imaging is also used to investigate the painful shoulder, as it is very sensitive for rotator cuff disease. MRI findings in adhesive capsulitis include thickening of the coracohumeral ligament and joint capsule with associated edema at the rotator cuff interval. MRI may demonstrate capsular thickening and decreased axillary pouch filling (
figure Figure 5).
Figure 5: An MRI
, showing showing decreased volume of the axillary recess highlighted by the arrow. (Modified from https://radiopaedia.org/cases/adhesive-capsulitis-shoulder-3)
It is estimated that approximately 5% of the general population, and 20% of patients with diabetes, will develop adhesive capsulitis in their lifetime. Adhesive capsulitis typically affects patients in their fifth or sixth decade, with a predilection for women. The non-dominant side is more frequently affected, though this bias may be a function of the patient’s ability to not use the non-dominant side, which thereby allows the soft tissues to stiffen. Symptoms will develop in the contralateral shoulder in approximately 20% of cases.
The initial painful phase of adhesive capsulitis can overlap with subacromial bursitis/rotator cuff tendinopathy. Isolated adhesive capsulitis is usually not associated with repetitive motion or specific overhead activities. Also, adhesive capsulitis on physical exam is characterized by stiffness in more than one plane of motion.
adhesive Adhesive capsulitis causes lost passive motion, whereas in cuff disease the range of passive motion is normal (though painful).
Night pain that awakens the patient from sleep may be due to occult malignancy that requires accurate diagnosis to guide treatment. Chronic shoulder pain with radiculopathy may suggest cervical spine pathology.
The most commonly employed treatment for adhesive capsulitis is physical therapy to prevent soft-tissue contracture as well as to improve shoulder motion.
Manipulation under anesthesia is generally regarded as a second-line treatment, chosen when non-operative treatments fail. Some potential risks include iatrogenic humeral dislocation or fracture, and soft tissue injury such as rotator cuff or labral tears.
Capsular capsular release may be chosen in severe cases.
Although adhesive capsulitis is a self-limiting disease,
but some patients may continue to demonstrate either shoulder pain and/or stiffness at 7-year follow-up.
Despite widespread use of physical therapy for the treatment of adhesive capsulitis, little evidence supports
it its use: a Cochrane database review was unable to confirm its benefit as a treatment. Still, retrospective case series evidence has demonstrated 90% of patients treated with a multi-directional stretching program were satisfied with their clinical result and given the pressure to take some action, this approach seems justified even in the face of poor evidence.
Secondary adhesive capsulitis is associated with medical conditions such as
Diabetes Mellitusdiabetes mellitus, thyroid disease and stroke; medical interventions such as prolonged immobilization, cardiac surgery and antiretroviral therapy for HIV; and injuries such as rotator cuff tears or proximal humerus fractures.
Recognize adhesive capsulitis and distinguish it clinically by history and physical exam from other common shoulder pathologies.