What is the recommended approach for reducing an anterior shoulder dislocation in a patient, considering their age, medical history, and potential complications?

Anterior Shoulder Dislocation Reduction

For anterior shoulder dislocation, obtain pre-reduction radiographs (AP in internal/external rotation PLUS axillary or scapula-Y view) to confirm diagnosis and exclude fractures, then perform prompt reduction using procedural sedation with propofol or etomidate plus opioid analgesia, followed by mandatory post-reduction imaging and neurovascular assessment. 1, 2

Pre-Reduction Imaging Protocol

Never attempt reduction without radiographic confirmation as this could worsen occult fracture-dislocations. 1, 2

Required views include:

• Anteroposterior (AP) in internal rotation 1, 2
• AP in external rotation 1, 2
• Axillary OR scapula-Y view (mandatory) - AP views alone miss posterior dislocations in over 60% of cases 1, 3

Key fractures to identify before reduction:

• Hill-Sachs deformity (posterolateral humeral head compression fracture) 1, 3
• Bony Bankart lesion (anterior glenoid rim fracture) 1, 3
• Greater tuberosity fractures 1, 4
• Surgical neck fractures 4

Reduction Approach Based on Fracture Pattern

Type I: Anterior dislocation with isolated greater tuberosity fracture

Attempt reduction under procedural sedation in the emergency department - 94% success rate with no fracture propagation. 4

Type II: Surgical neck fracture with or without greater tuberosity involvement

Do NOT attempt reduction under sedation - proceed directly to general anesthesia due to risk of significant displacement (occurred in 5 cases in one series after attempted sedation reduction). 4

Posterior dislocation with any fracture

Reduce under general anesthesia only - no attempts should be made under sedation. 4

Procedural Sedation Options

Propofol or etomidate with opioid analgesia are the recommended agents for shoulder reduction in the emergency department. 5, 1

Propofol

• Provides effective sedation with shorter recovery time (14.9 minutes) compared to midazolam (76.4 minutes) 5
• Lowest rate of respiratory depression compared to other agents (methohexital, fentanyl/midazolam, etomidate) 5
• Oxygen saturation maintained >90% in 95% of patients 5
• Brief bag-mask ventilation required in only 1% of cases 5

Etomidate

• 90% procedural success rate for shoulder reduction 5
• Median procedural sedation time of 10 minutes versus 23 minutes for midazolam (P<0.001) 5
• Myoclonus occurs in 21% of patients but does not affect efficacy 5
• Brief bag-mask ventilation required in <2% of cases 5

Critical sedation caveat: When combining benzodiazepines with opioids, administer the opioid first (which poses greater respiratory depression risk), then carefully titrate the benzodiazepine. 5

Reduction Without Sedation (Alternative Approach)

While sedation is the guideline-recommended approach, gentle traction-abduction-external rotation techniques without sedation have 90-95% success rates in recent studies. 6, 7, 8, 9

Consider sedation-free techniques when:

• Sedation resources unavailable 6, 7
• Patient refuses sedation 8
• Medical comorbidities increase sedation risk 8

However, this contradicts guideline recommendations for prompt reduction with appropriate sedation, so sedation remains the standard of care. 1

Post-Reduction Protocol

Mandatory Post-Reduction Imaging

Obtain radiographs immediately after reduction to confirm successful reduction and evaluate for fractures obscured by the dislocation. 1, 2

Neurovascular Assessment

Evaluate axillary nerve function and vascular integrity following every reduction:

• Axillary nerve: Test sensation over lateral deltoid, assess deltoid motor function 1, 2
• Vascular: Palpate radial pulse, assess capillary refill, compare bilateral blood pressures 1, 2

If vascular compromise suspected (especially with proximal humeral fractures), obtain CT angiography immediately. 1, 2

Age-Specific Considerations

Patients <35 years old

• Higher recurrence risk due to labroligamentous injury and persistent instability 1, 3
• Consider MR arthrography or non-contrast MRI to evaluate labral tears, capsular injuries, and bone loss that predict recurrence 1

Patients >40-60 years old

• Significantly higher risk of rotator cuff tears 1, 2
• Look for weakness in external rotation, abduction, or internal rotation 1
• Do not overlook associated rotator cuff pathology - this is a common pitfall in older patients 1, 2

Timing of Reduction

Perform reduction promptly - delays increase the risk of neurovascular complications. 1, 2

Critical Pitfalls to Avoid

1. Never reduce without pre-reduction radiographs - could worsen fracture-dislocations 1, 2
2. Never rely on AP views alone - obtain axillary or scapula-Y view to avoid missing posterior dislocations 1, 2, 3
3. Never attempt sedation reduction with surgical neck fractures - requires general anesthesia 4
4. Never skip post-reduction neurovascular exam - axillary nerve and artery injuries occur 1, 2
5. Never overlook rotator cuff tears in patients >40 years - common associated injury 1, 2
6. Never delay reduction - increases complication rates 1, 2