Rotator cuff tear

Background

Shoulder anatomy, anterior.

Shoulder anatomy, posterior.

• Majority of tears occur due to chronic impingement in patients >40yrs
• Acute tears require significant trauma: shoulder dislocation, FOOSH
• Consider rotator cuff tear in patient with weakness for >3wk after acute shoulder dislocation
• Supraspinatus is most commonly affected tendon

Clinical Features

• Acute Injury
  • "Tearing" sensation in shoulder followed by severe pain / inability to raise arm
  • Inability to abduct or externally rotate arm against even minimal resistance
  • Drop arm test is positive
  • Local swelling
• Chronic Injury
  • Gradual and progressive pain, worse at night
  • Pain localizes to lateral aspect of upper arm
  • Arm elevation, external rotation, and lifting objects worsens the pain
• Exam
  • Disuse atrophy may be present in chronic tears
  • TTP lateral aspect of upper arm or in subacromial region

Rotator Cuff Tests

• Supraspinatus Test (+ LR 3.2)
  • Abduct arm to 90', forward flex it 30' with thumb down ("empty beer can position")
  • Test for pain/weakness against resistance to continued abduction
• Infraspinatus and Teres Minor Test
  • Stabilize the elbow against the patient's waist and bend the elbow to 90'
  • Test for pain/weakness against resistance to external rotation
• External rotation lag sign - more specific to teres minor, given overlap between infraspinatus and teres minor
  • Support the arm to 20-30 degrees in scapular plane, externally rotated, elbow flexed to 90 degrees
  • Positive test is pain or difficulty in keeping the arm from internally rotating when clinician lets go
• Subscapularis (+ LR 1.9)
  • Place hand behind lower back
  • Test for pain/weakness as patient attempts to push examiner's hand away by moving dorsum of hand away from back
• Drop arm test
  • Patient is unable to hold or smoothly lower an extended arm at 90' of shoulder abduction with out dropping it

Differential Diagnosis

Shoulder and Upper Arm Diagnoses

Traumatic/Acute:

• Shoulder Dislocation
  • Anterior shoulder dislocation
  • Posterior shoulder dislocation
  • Inferior shoulder dislocation
• Clavicle fracture
• Humerus fracture
• Scapula fracture
• Acromioclavicular joint injury
• Glenohumeral instability
• Rotator cuff tear
• Biceps tendon rupture
• Triceps tendon rupture
• Septic joint

Nontraumatic/Chronic:

• Rotator cuff tear
• Impingement syndrome
• Calcific tendinitis
• Adhesive capsulitis
• Biceps tendinitis
• Subacromial bursitis
• Cervical radiculopathy

Refered pain & non-orthopedic causes:

• Referred pain from
  • Neck
  • Diaphragm (e.g. gallbladder disease)
• Brachial plexus injury
  • Rucksack paralysis
• Axillary artery thrombosis
• Thoracic outlet syndrome
• Subclavian steal syndrome
• Pancoast tumor
• Myocardial infarction
• Pneumonia
• Pulmonary embolism

Evaluation

• See Shoulder (Tests)

Imaging

• Diagnosis should rely on clinical findings; cannot use imaging to rule-out tear
• May give some diagnostic information:
  • Narrowing of acromiohumeral space (<7mm) is most specific sign
  • May see humeral head sclerosis, osteophytes on undersurface of acromion/clavicle

Management

• Arm sling until acute symptoms subside
• Analgesia
  • NSAIDs, opioids, ice
• Exercises
  • Pendulum swings
    • Patient bends slightly at waist with arm hanging freely in front of body
    • Arms should be swung in gentle arcs of motion both clockwise and counter-clockwise
    • Swing to level of pain tolerance x 5-10min TID-QID
  • Walk fingers up wall
    • Stand sideways an arm's length from wall and walk fingers up wall to level of pain tolerance TID-QID

Disposition

• Ortho follow-up within 1 week

See Also

• Shoulder diagnoses