Rotator cuff tear

Background

  • 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[1]
    • 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:

Nontraumatic/Chronic:

Refered pain & non-orthopedic causes:

Evaluation

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
  • 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

References

  1. Collin P et al. What is the Best Clinical Test for Assessment of the Teres Minor in Massive Rotator Cuff Tears? Clin Orthop Relat Res. 2015 Sep;473(9):2959-66.