Shoulder dislocation

Background

Left shoulder and acromioclavicular joints with ligaments.

Shoulder anatomy, anterior.

Shoulder anatomy, posterior.

• Humerus separates from the scapula at the glenohumeral joint
• Partial dislocation of the shoulder is referred to as subluxation
• Dislocation duration inversely correlated with likelihood of successful ED reduction

Shoulder dislocation types

• Anterior shoulder dislocation (~95%)
• Posterior shoulder dislocation (~5%)
• Inferior shoulder dislocation (<1%)

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

Workup

• Plain film X-ray
  • Include anteroposterior, scapular Y, and axillary views
  • Associated fractures include:
    • Hills-Sachs: cortical depression in the humeral head
    • Bankart: glenoid labrum disruption with bony avulsion
    • Humeral greater tuberosity fracture
• Consider joint ultrasound

Diagnosis

• 

  Anterior shoulder dislocation

• 

  Anterior shoulder dislocation on Y-view

• 

  Anterior shoulder dislocation with fracture

• 

  Inferior shoulder dislocation

• 

  Posterior shoulder dislocation

Management

Reduction

• Do not attempt to reduce chronic dislocations (>4 weeks) in ED due to risk of arterial injury - these require reduction in the OR
• Lower complications, equal pain control, and shorter ED stay with intra-articular lidocaine vs. procedural sedation
  • 20 mL of 1% lidocaine intra-articular injection
• See individual types for specific techniques:
  • Anterior shoulder dislocation
  • Posterior shoulder dislocation
  • Inferior shoulder dislocation

Post-Reduction

• Post-reduction film to confirm
• Sling and swathe or shoulder immobilizer x1 week / until orthopedics follow-up
  • Encourage daily range of motion exercises (minus abduction + external rotation) to prevent adhesive capsulitis

Disposition

• Uncomplicated dislocation can be discharged after reduction

Prognosis

• Recurrence rate around 27% if older than 30 years and 72% if younger than 23 years

See Also

• Shoulder diagnoses

External Links

• Good all-round shoulder reduction technique lecture
• Keeping Up in EM Shoulder Reduction Video
• Merk Manual - Shoulder dislocations

Video

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