Lecture on Rotator Cuff Tears

Introduction

• Topic: Rotator cuff tears
• Objective: Understand anatomy, function, causes, and diagnosis of rotator cuff tears

Anatomy of the Rotator Cuff

• Rotator Cuff Components: Muscles, tendons, and bursae around the shoulder joint
• Key Muscles:
  • Subscapularis:
    • Origin: Subscapular fossa
    • Insertion: Lesser tubercle of humerus
    • Function: Internal rotation at the shoulder joint
  • Supraspinatus:
    • Origin: Supraspinous fossa
    • Insertion: Greater tubercle of humerus
    • Function: Abduction (first 20-30 degrees)
  • Infraspinatus:
    • Origin: Infraspinous fossa
    • Insertion: Greater tubercle
    • Function: External rotation
  • Teres Minor:
    • Origin: Inferior angle of scapula
    • Insertion: Greater tubercle
    • Function: External rotation
• Mnemonic for Muscles: SITs (Supraspinatus, Infraspinatus, Teres Minor, Subscapularis)
• Bursae:
  • Subacromial bursa
  • Subscapular bursa

Causes of Rotator Cuff Tears

• Extrinsic Factors:
  • Bony prominences (e.g., bone spurs, osteophytes)
  • Ligament instability or injury
  • Subacromial bursitis causing compression
• Intrinsic Factors:
  • High tensile overload from repetitive overhead activities
  • Aging: Micro tears, calcifications, reduced microvascularity
  • Systemic diseases: Rheumatoid arthritis, diabetes, connective tissue disorders

Diagnosis of Rotator Cuff Tears

• Symptoms:
  • Shoulder pain, particularly at night
  • Pain near anterior deltoid
• Physical Examination:
  • Inspect for muscle atrophy
  • Palpate for tenderness
  • Test range of motion: Active (reduced) vs. passive (preserved)
  • Special strength testing for specific rotator cuff muscles
• Special Tests:
  • Painful arc test
  • Drop arm test
  • External rotation weakness
• Imaging:
  • X-ray: Rule out fractures, dislocations, and superior migration of the humeral head
  • Ultrasound: Dynamic testing of the tendon
  • MRI: Gold standard for detecting tears, especially full-thickness tears

Treatment of Rotator Cuff Tears

• Conservative Management:
  • NSAIDs for inflammation
  • Subacromial lidocaine for diagnostic and therapeutic use
  • Intra-articular corticosteroids
  • Physical therapy: Strengthening range of motion, shoulder stability
• Surgical Options:
  • Indications: Conservative treatment failure, traumatic tears, high mobility need, younger patients
  • Arthroscopic approach preferred over open surgery for repair