Adhesive Capsulitis

Primary adhesive capsulitis (AC) is a self-limited, idiopathic condition that is most commonly seen in women over 40 years of age. It is characterized by atraumatic and gradual onset of symptoms of pain and limited range of motion (ROM). Risk factors include diabetes mellitus and hypothyroidism. Secondary adhesive capsulitis can be seen following severe trauma, iatrogenic or otherwise.

Contrast-enhanced MRI may show enhancement in the rotator interval and enhancing soft-tissue partially encasing the biceps anchor. Arthrographic criteria of adhesive capsulitis include:

• Limited (7–10 cc) capacitance of the glenohumeral joint to contrast injection
• Small, dependent axillary fold
• Irregularity of the anterior capsular insertion at the anatomic neck of the humerus

Four stages of AC have been defined based on clinical criteria. There is some correlation between clinical stage and MRI findings:

Stage	Clinical and Pathologic Findings	MRI Findings
1 0–3 months	Pain with active and passive motion Limitation of forward flexion, abduction, internal rotation, external rotation Pathology: hypertrophic, hypervascular synovitis; normal capsule	Capsular and synovial thickening measured in the axillary pouch (mean of 4 mm) Rotator interval scarring.
2 3-9 months	Chronic pain with active and passive motion Significant limitation of forward flexion, abduction, internal rotation, external rotation Pathology: hypertrophic, hypervascular synovitis with perivascular and subsynovial scar, scar formation in the underlying capsule	Capsular and synovial thickening measured in the axillary pouch (mean of 7.5 mm) Rotator interval scarring. Increased signal intensity of the joint capsule and synovium
3 9-15 months	Minimal pain except at end motion Significant limitation of motion with rigid "end feel" Pathology: "burned out" synovitis without significant hypertrophy or hypervascularity. Dense scar formation of the capsule	Capsular and synovial thickening measured in the axillary pouch (mean of 5.5 mm) Rotator interval scarring.
4 15-24 months	Minimal pain Progressive improvement in ROM	Capsular and synovial thickening measured in the axillary pouch (mean of 4 mm) Rotator interval scarring.

References

Sofka CM, Ciavarra GA, Hannafin JA, Cordasco FA, Potter HG. Magnetic resonance imaging of adhesive capsulitis: correlation with clinical staging. HSS J. 2008 Sep;4(2):164-9.