Shoulder dislocation

Background

• Cochrane review notes lower complications, equal pain control, and shorter ED stay with intra-articular lidocaine vs. procedural sedation
  • 20mL of 1% lidocaine intra-articular injection

Types

• Shoulder dislocation
  • Anterior shoulder dislocation
  • Posterior shoulder dislocation
  • Inferior shoulder dislocation

Anterior Dislocation

Background

• >99% are anterior dislocation assoc w/ indirect blow
• Must rule-out axillary nerve injury
• Consider intra-articular lidocaine (10-20mL) as alternative to procedural sedation

Clinical Features

• Arm held in abduction w/ shoulder lacking normal rounded contour
• Difficulty (painful) touching ipsilateral arm to contralateral shoulder

Imaging

• Prereduction radiographs advised for traumatic mechanism (rule-out fx-dislocation)
• AP
  • Will show dislocation
• Scapular lateral or "Y"
  • Will show whether dislocation is anterior or posterior

Management

• Reduce (see techniques below)
• Post-reduction: sling w/ shoulder in adduction/internal rotation
• Ortho referral for 1st-time dislocation

Complications

1. Recurrent dislocation (>90% in age <20yr)
2. Bony injuries:
   1. Usually do not affect management
      1. Hill-Sachs lesion (compression fracture of humeral head) - occur in up to 40% of cases; more likely with recurrent anterior dislocations
      2. Bankart lesion (injury to inferior glenoid labrum) - occurs in 10-20% of cases
3. Axillary nerve - occurs in up to 14% of cases; usually transient deficits
4. Axillary artery - rare
5. Rotator cuff tear

Reduction Techniques

• Traction-Countertraction

• External Rotation (Kocher)

• Milch

• Stimson

1. Place pt prone on edge of table.
2. If pt sedated or intoxicated, secure pt to stretcher with belts or sheets
3. Shoulder is placed over floor while the pt is prone so that the arm can fall 90 degrees to pt and floor.
4. Attach a 5-kg weight to the arm, and the patient maintains this position for 20–30 min, if necessary.
5. Occasionally, gentle external and internal rotation of the shoulder with manual traction aids reduction.
6. Consider combining with scapular manipulation (The inferior tip of the scapula is pushed medially and dorsally with the thumbs while the superior aspect of the scapula is stabilized with the fingers of the superior hand)

• FARES (Fast, Reliable, and Safe) Method: No sedation required!

1. Apply traction while holding wrist to the affected limb in a neutral position beside on a supine patient
2. Oscillate limp up and down (anteriorly/posteriorly) while continuing to apply traction and start slowly abducting the limb.
3. Once abducted to 90 degrees, externally rotate and continue with ongoing traction and oscillations past this position. Reduction is usually achieved once abducted to 120 degrees.

• Cunningham Technique:
  • No sedation required although analgesia still administered
  • Massage the bicipital muscle in the mid humerus
  • Maintain the the patient's affected arm adducted, and the elbow flexed, massaging the biceps
  • At the same time the patient is told to move the shoulder superiorly (up), and posteriorly (back) to allow the humeral head to relocate back into the glenoid fossae.

Posterior Dislocation

Background

• Via forceful internal rotation/adduction (sz, electric shock) or blow to ant shoulder
• Neurovascular and rotator cuff tears are less common than in ant dislocations

Clinical Features

• Prominence of posterior shoulder and ant flattening of normal shoulder contour
• Pt unable to rotate or abduct affected arm

Imaging

• Scapular "Y" view shows humeral head in posterior position

Management

• Reduce
  • Traction applied to adducted arm in long axis of humerus
  • Assistant pushes humeral head anteriorly into glenoid fossa
• Spling, ortho f/u

Inferior Dislocation

Background

• Assoc w/ significant soft tissue trauma or fracture
• Via hyperabduction force which levers the humeral neck against the acromion

Clinical Features

• Pt p/w humerus fully abducted with hand on or behind the head
• Humeral head can be palpated on lateral chest wall

Management

• Reduce
  • Traction in upward and outward direction
• Sling, ortho f/u (rotator cuff tear is the norm)

Further Reading

Good all-round shoulder reduction technique lecture

Keeping Up in EM Shoulder Reduction Video

References

• Tintinalli
• Roberts:Clinical Procedures in EM. 5th ed
• https://www2.aofoundation.org/wps/portal/!ut/p/c0/04_SB8K8xLLM9MSSzPy8xBz9CP0os3hng7BARydDRwN3QwMDA08zTzdvvxBjIwN_I_2CbEdFADiM_QM!/?redfix_url=&implantstype=&segment=Proximal&bone=Humerus&classification=11-A1.3&showPage=redfix&treatment=Operative&method=Closed%20reduction%3B%20screw%20fixation