Rotator Cuff Tears Lecture Notes

Introduction

• Focus on understanding rotator cuff tears.
• Reference to follow along with detailed notes and illustrations in the description.
• Encourage engagement: like, comment, and subscribe.

Understanding the Rotator Cuff

Anatomy Overview

• Importance of knowing the muscles, tendons, and bursa involved in the rotator cuff.
• Focus on key muscles:
  • Subscapularis:
    • Originates in the subscapular fossa.
    • Inserts on the lesser tubercle of the humerus.
    • Function: Internal rotation of the humerus at the shoulder joint.
  • Supraspinatus:
    • Originates in the supraspinous fossa.
    • Inserts on the greater tubercle of the humerus.
    • Function: Abduction (first 20-30 degrees) of the humerus.
  • Infraspinatus:
    • Originates from the infraspinous fossa.
    • Inserts on the greater tubercle.
    • Function: External rotation of the humerus.
  • Teres Minor:
    • Originates near the inferior angle of the scapula.
    • Inserts on the greater tubercle.
    • Function: External rotation of the humerus.

Mnemonic for Rotator Cuff Muscles

• SITS: Supraspinatus, Infraspinatus, Teres Minor, Subscapularis.

Additional Structures

• Labrum: Fibrocartilaginous structure around the glenoid cavity.
• Capsule: Surrounds the shoulder joint.
• Glenohumeral Ligaments: Provide stability (superior, middle, inferior).
• Bursa:
  • Subacromial Bursa: Involved in many diseases; located beneath the acromion process.
  • Subscapular Bursa: Lesser significance but still important.

Causes of Rotator Cuff Tears

Pathophysiological Mechanisms

Extrinsic Mechanisms

1. Bony Prominences (e.g., osteophytes, bone spurs) can compress tendons.
2. Ligament Injuries can lead to shoulder instability, increasing stress on the rotator cuff.
3. Subacromial Bursitis: Inflammation leading to compressive forces on the tendons.

Intrinsic Mechanisms

1. Tensile Overload: Repetitive overhead activities (e.g., athletes like pitchers).
2. Aging: Leads to micro tears, calcifications, and reduced microvascularity.
3. Systemic Diseases: Conditions like rheumatoid arthritis and diabetes affect tendon integrity.

Clinical Diagnosis of Rotator Cuff Tears

History and Symptoms

• Pain Location: Anterior deltoid area, worse at night.
• Inspection: Look for signs of atrophy (e.g., infraspinatus).
• Palpation: Tenderness near the greater and lesser tubercles, coracoid process.
• Range of Motion: Reduced active range, preserved passive range.

Strength Testing

• Evaluate strength of:
  • Supraspinatus: Abduction.
  • Infraspinatus/Teres Minor: External rotation.
  • Subscapularis: Internal rotation.

Special Tests

1. Painful Arc Test: Positive test can indicate impingement.
2. Drop Arm Test: Tests supraspinatus function.
3. External Rotation Weakness: Indicates possible infraspinatus or teres minor tears.

Imaging Techniques

• X-ray: Rule out fractures, dislocations, or arthritis.
• Ultrasound: Dynamic assessment of tendon motion.
• MRI: Gold standard for detecting tears (partial or full thickness).
• CT Arthrogram: Alternative if MRI is contraindicated.

Treatment of Rotator Cuff Tears

Conservative Management

1. NSAIDs: Reduce inflammation (e.g., ibuprofen, naproxen).
2. Corticosteroid Injections: Directly in the joint or bursa to reduce inflammation.
3. Physical Therapy: Focus on range of motion and stability.

Indications for Surgical Intervention

• Conservative measures fail.
• Traumatic tears.
• High activity demands (e.g., athletes).

Surgical Approaches

• Arthroscopic Repair: Preferred method for repairing torn tendons.
• Open Surgery: Less common, more invasive.

Conclusion

• Recap of key points about rotator cuff anatomy, causes, diagnosis, and treatment.
• Invitation for questions and further discussion.