What are the differences between adhesive capsulitis and rotator cuff tendonitis in terms of history, physical exam, workup, and treatment?

Differences Between Adhesive Capsulitis and Rotator Cuff Tendinopathy

Adhesive capsulitis and rotator cuff tendinopathy are distinct shoulder conditions with different pathophysiology, clinical presentations, diagnostic findings, and treatment approaches.

History

Adhesive Capsulitis

• Onset: Typically insidious, gradual onset of pain
• Age: Most common in patients 40-60 years old
• Risk factors: Diabetes, thyroid disorders, stroke, prolonged immobilization
• Pain pattern: Progressive pain that worsens at night and at rest
• Stages: Follows three distinct clinical phases:
  1. Painful/freezing phase (2-9 months): Severe pain with progressive stiffness
  2. Frozen/adhesive phase (4-12 months): Decreased pain but significant stiffness
  3. Thawing phase (5-24 months): Gradual return of motion

Rotator Cuff Tendinopathy

• Onset: Often related to specific activities or overuse
• Age: Common in athletes who throw repetitively and laborers who work with arms overhead 1
• Risk factors: Repetitive overhead activities, sports (especially throwing), aging
• Pain pattern: Activity-related pain that improves with rest
• Progression: Gradually increasing load-related localized pain coinciding with increased activity 1

Physical Examination

Adhesive Capsulitis

• Range of motion: Global limitation of both active AND passive range of motion in all planes (pathognomonic finding)
• Pain pattern: Pain at extremes of available motion
• Capsular pattern: External rotation most limited, followed by abduction and internal rotation
• Special tests: Limited value as ROM restriction is the key finding

Rotator Cuff Tendinopathy

• Range of motion: Typically preserved passive ROM with painful active motion
• Pain pattern: Pain with specific movements that load the affected tendon
• Special tests:
  • Hawkins' test: Pain with forcible internal rotation with arm flexed forward at 90° (92% sensitive, 25% specific) 1
  • Neer's test: Pain with full forward flexion between 70-120° (88% sensitive, 33% specific) 1
  • Pain with resisted movements specific to the affected tendon

Diagnostic Workup

Adhesive Capsulitis

• Plain radiography: Usually normal, used to exclude other pathologies
• MRI findings:
  • Thickened coracohumeral ligament (4.2mm vs 2.4mm in normal shoulders) 2
  • Thickened articular capsule in rotator cuff interval (7.2mm vs 4.4mm) 2
  • Partial or complete obliteration of the subcoracoid fat triangle (73% vs 13%) 2
  • Synovitis-like abnormality around the long biceps tendon 2
• MR arthrography: Decreased joint volume, capsular thickening

Rotator Cuff Tendinopathy

• Plain radiography: May show acromial morphology, calcifications
• Ultrasound: Can identify tendon thickening, partial or full-thickness tears
• MRI: Shows tendon degeneration, partial or full-thickness tears, muscle atrophy

Treatment

Adhesive Capsulitis

• Conservative management:

  • Physical therapy focusing on stretching exercises 3, 4
  • NSAIDs for pain control 3
  • Long-term outcomes with conservative treatment show significant improvement in all measured movement directions 3

• Interventional options:

  • Intra-articular corticosteroid injections
  • Hydrodilatation
  • Manipulation under anesthesia
  • Arthroscopic capsular release (for refractory cases)

Rotator Cuff Tendinopathy

• Conservative management:

  • Relative rest and activity modification 1
  • Eccentric strengthening exercises 1
  • NSAIDs for acute pain relief 1
  • Ice application 1

• Interventional options:

  • Corticosteroid injections (more effective than NSAIDs in acute phase) 1
  • Ultrasound therapy (weak evidence) 1
  • Extracorporeal shock wave therapy (ESWT) 1
  • Surgical options for refractory cases (excision of abnormal tendon tissue) 1

Key Differences to Remember

1. Motion limitation: Adhesive capsulitis affects both active AND passive motion; rotator cuff tendinopathy primarily affects active motion
2. Pain pattern: Adhesive capsulitis has pain at rest and night pain; rotator cuff tendinopathy has activity-related pain
3. Natural history: Adhesive capsulitis typically follows a self-limiting course over 1-3 years; rotator cuff tendinopathy may persist without treatment
4. Treatment focus: Adhesive capsulitis treatment focuses on restoring motion; rotator cuff tendinopathy treatment focuses on tendon healing and strengthening

Common Pitfalls

• Failing to distinguish between these conditions can lead to inappropriate treatment
• Gleno-humeral exploration during arthroscopic procedures increases risk of developing adhesive capsulitis (OR 5.60) 5
• Overuse of corticosteroid injections may lead to tendon weakening in rotator cuff tendinopathy
• Aggressive stretching in acute rotator cuff tendinopathy may worsen symptoms
• Insufficient stretching in adhesive capsulitis may prolong recovery

Remember that approximately 80% of patients with overuse tendinopathies fully recover within three to six months with appropriate conservative treatment 1, while adhesive capsulitis may take 1-3 years to resolve even with treatment.