How do you differentiate and treat adhesive capsulitis vs rotator cuff syndrome in a patient with shoulder pain and stiffness?

Differentiating Adhesive Capsulitis from Rotator Cuff Syndrome

The critical distinguishing feature is that adhesive capsulitis demonstrates equal restriction of both active AND passive range of motion in all planes (particularly external rotation), while rotator cuff syndrome shows preserved passive motion with weakness and pain primarily during active movement. 1

Key Clinical Differentiation

Range of Motion Pattern

• Adhesive capsulitis: Equal restriction of active and passive motion in all planes, with external rotation being the most severely affected, followed by abduction 1, 2
• Rotator cuff syndrome: Focal weakness with decreased range of motion during abduction with external or internal rotation, but passive motion remains relatively preserved 3

Pain Characteristics

• Adhesive capsulitis: Gradual onset of diffuse shoulder pain with progressive stiffness, affecting all movements equally 4
• Rotator cuff syndrome: Pain and weakness during specific movements, particularly during arm cocking, acceleration, release, and deceleration phases of overhead activities 3

Physical Examination Findings

• Adhesive capsulitis: Capsular pattern of restriction (external rotation > abduction > internal rotation), with a firm endpoint on passive testing 1
• Rotator cuff syndrome: Focal weakness on resisted testing, pain with specific provocative maneuvers, but full passive range of motion can typically be achieved 3

Age and Demographics

• Adhesive capsulitis: Rarely occurs under age 40, with peak incidence between 40-65 years, more common in women 5
• Rotator cuff syndrome: Can occur at any age depending on activity level and mechanism of injury 3

Diagnostic Imaging Approach

When Clinical Diagnosis is Unclear

• MRI without contrast is rated 9 (usually appropriate) for evaluating both conditions when radiographs are noncontributory 3
• Ultrasound is equally appropriate (rating 9) depending on local expertise for rotator cuff evaluation 3
• MR arthrography demonstrates capsular thickening, coracohumeral ligament thickening, and rotator interval fibrosis in adhesive capsulitis 6

Imaging Findings

• Adhesive capsulitis: Increased periarticular activity on bone scintigraphy, capsular thickening on MRI, particularly in the rotator interval and axillary recess 1, 2, 6
• Rotator cuff syndrome: Tendon tears (undersurface or full-thickness), tendinopathy, or impingement findings on MRI or ultrasound 3

Treatment Algorithms

For Adhesive Capsulitis

• Begin with gentle, progressive stretching exercises as first-line treatment 4
• Add corticosteroid injections if conservative therapy fails to provide symptomatic improvement 7
• Consider capsular distention, manipulation under anesthesia, or surgical capsular release only after ≥6 months of failed physical therapy with continued functional disability 4
• Critical pitfall: Avoid aggressive overhead pulley exercises, which can worsen the condition, particularly in post-stroke patients 5, 1

For Rotator Cuff Syndrome

• Complete rest from aggravating activities (especially throwing) until asymptomatic 3
• Rehabilitation focusing on rotator cuff and scapular stabilizer strengthening, re-establishing proper shoulder and spine mechanics, and restoring range of motion 3
• Progressive throwing program over 1-3 months (depending on severity) once pain-free motion and strength are achieved 3
• Return to activity only after completing a functional, progressive, individualized program without symptoms 3

Critical Differential Diagnosis Considerations

Other conditions that must be excluded include: degenerative joint disease, crystal arthropathies, septic arthritis, calcific tendinitis, acromioclavicular joint disease, and subacromial/subdeltoid bursitis, as these can produce overlapping clinical pictures 1, 6

Red Flags Requiring Immediate Evaluation

• Suspect septic arthritis: Perform ultrasound-guided or fluoroscopy-guided arthrocentesis (both rated 9) 3
• Acute trauma or suspected fracture: Obtain radiographs first, followed by CT if more detail needed preoperatively 3

Common Pitfalls to Avoid

• Do not assume all shoulder stiffness is adhesive capsulitis; rotator cuff pathology can coexist and must be actively excluded 7, 6
• Do not delay formal physical therapy beyond 6-8 weeks post-injury or post-surgery, as this may result in permanent shoulder dysfunction 5
• Do not use aggressive overhead pulley exercises in suspected adhesive capsulitis, particularly in neurologically compromised patients 5, 1
• Do not overlook that shoulder pain in certain populations (e.g., polymyalgia rheumatica patients) may be due to adhesive capsulitis or rotator cuff disease rather than disease relapse 3