Rotator Cuff Pathology

Anatomy & Biomechanics - Shoulder's Stability Crew

• Rotator Cuff (SITS Muscles) 📌: Four muscles crucial for dynamic glenohumeral joint stability and movement.

  Muscle	Primary Action	Innervation
  Supraspinatus	Abduction (initial 0-15°)	Suprascapular n. (C5,C6)
  Infraspinatus	External Rotation	Suprascapular n. (C5,C6)
  Teres Minor	External Rotation	Axillary n. (C5,C6)
  Subscapularis	Internal Rotation	Upper/Lower Subscapular nn. (C5,C6)

• Key Blood Supply: Suprascapular artery, anterior & posterior circumflex humeral arteries, thoracoacromial artery.
• Essential Biomechanics:
  • Glenohumeral joint compression & centering (concavity compression).
  • Force couples (e.g., deltoid-cuff) for efficient, coordinated motion.
  • Humeral head depression during elevation, preventing superior escape & impingement.

⭐ Supraspinatus initiates abduction (first 0-15°) and is the most frequently injured rotator cuff muscle.

Etiology & Types - Tears & Tantrums

Etiology:

• Intrinsic Factors: Ageing, hypovascularity ("critical zone" - supraspinatus), tendinosis.
• Extrinsic Factors:
  • Subacromial Impingement:
    • Primary: Acromial morphology (Bigliani type II/III), AC joint osteophytes, coracoacromial (CA) ligament hypertrophy.
    • Secondary: Glenohumeral (GH) instability, scapular dyskinesis, muscle imbalance.
  • Internal (Posterosuperior) Impingement: Common in overhead athletes, associated with GIRD (Glenohumeral Internal Rotation Deficit).
  • Acute Trauma (e.g., FOOSH - Fall On Outstretched Hand).

Risk Factors:

• Age >40 years
• Repetitive overhead activities
• Smoking
• Diabetes Mellitus (DM)
• Trauma history

Spectrum of Pathologies:

• Subacromial Impingement Syndrome
• Rotator Cuff (RC) Tendinopathy
• Subacromial-Subdeltoid (SASD) Bursitis
• Calcific Tendinitis
• RC Tears

Rotator Cuff Tear Classification:

Diagnosis & Tests - Spotting the Strain

• Symptoms:

  • Anterolateral shoulder pain, aggravated by overhead activities.
  • Night pain, disturbing sleep.
  • Weakness, difficulty lifting arm.
  • Crepitus or clicking sounds.

• Signs:

  • Tenderness: Greater tuberosity, subacromial space.
  • Painful arc: Typically between 60°-120° of abduction.
  • Atrophy: Supraspinatus/Infraspinatus (chronic tears).

⭐ Night pain is a highly suggestive symptom of rotator cuff pathology.

• Special Tests:

• Imaging:

  • X-ray (AP, Outlet, Axillary): May show calcification, acromial spur, ↓acromiohumeral distance (<7mm).
  • USG: Dynamic, good for detecting tears; operator-dependent.
  • MRI: Gold standard for tear characterization (size, retraction, fatty infiltration - Goutallier stages 0-4).

• Diagnostic Pathway:

Treatment Approaches - Fixing the Fray

• Conservative (First-line for most):
  • Physiotherapy: Range of Motion (ROM), periscapular & rotator cuff strengthening.
  • NSAIDs: For pain & inflammation.
  • Injections: Corticosteroid (subacromial) for persistent pain (max 2-3/year).
• Surgical Indications:
  • Failed conservative management >3-6 months.
  • Acute full-thickness tears in young, active individuals.
  • Significant weakness, tear size >1-1.5 cm or >50% thickness.

• Surgical Techniques: Arthroscopic repair is common; types include single-row, double-row.
• Post-op Rehab: Phased approach: sling protection (4-6 weeks), then progressive ROM & strengthening. Return to activity in 4-6+ months.

⭐ Early motion is often emphasized post-operatively for smaller tears, while larger repairs might require more protection and a slower rehabilitation progression to ensure adequate tendon healing to bone.

High‑Yield Points - ⚡ Biggest Takeaways

• Supraspinatus is the most frequently torn rotator cuff muscle.
• Painful arc syndrome (pain 60-120° abduction) is a classic sign.
• Drop arm test and Empty can test assess Supraspinatus integrity.
• MRI is gold standard for full-thickness tears and surgical planning.
• Subacromial impingement is a common precursor to rotator cuff tears.
• Surgical repair for acute full-thickness tears in active individuals.
• Key symptoms: shoulder pain (especially at night) and weakness.