Rosen & Barkin's 5-Minute Emergency Medicine Consult (648 page)

• Shoulder is a very dynamic joint, prone to injury.
  
• Anterior dislocation (90–96%):
  
  • Injury is from direct or indirect forces on the abducted and externally rotated arm.
    
  • Injury may also result from a direct blow to posterolateral aspect of shoulder.
    
• Posterior dislocation:
  
  • Often missed
    
  • Forces on the adducted and internally rotated arm result in posterior dislocation of humeral head in relation to glenoid fossa.
    
  • Most common mechanism is seizure and sudden contraction of all the posterior muscle groups.
    
  • Other mechanisms include electrocution and direct blow to anterior shoulder.
    
• Inferior dislocation (rare):
  
  • Luxatio erecta
    
  • Hyperabduction of arm, tear of rotator cuff, and rotation of arm 180° above head
    
  • Commonly seen after a fall from a height:
    
    • Arm has struck object on descent and is thrust above the head.
      
  • Often accompanied by neurovascular injury and fracture
    

Dislocation is rare in children: Epiphyseal fractures must be suspected.

Dislocation is often accompanied by fracture.

• Falls from height
  
• Impact injuries
  
• Distraction injuries of upper arm
  
• Seizures
  
• Electrocution
  

DIAGNOSIS

• Severe pain in the affected shoulder
  
• Anterior dislocation:
  
  • Shoulder is squared off.
    
  • Prominent acromion process and palpable anterior fullness
    
  • Arm is held in slight abduction and external rotation.
    
• Posterior dislocation:
  
  • Coracoid process is prominent, with a palpable posterior bulge.
    
  • Arm is held in slight adduction and internal rotation.
    
• Inferior dislocation (luxatio erecta):
  
  • Rare but easy to identify
    
  • Arm is shortened and fixed above head as if raised to ask a question.
    
• Head of humerus may be palpable on the lateral chest wall.
  

• Evaluate neurovascular status of distal arm.
  
• Retest neurovascular status after any manipulation.
  
• Dislocation requires prompt treatment:
  
  • Incidence of post-traumatic arthritis increases with time dislocation is untreated.
    
  • Plain films of the shoulder should be obtained immediately.
    
  • Even in clinically obvious cases, films should be obtained before manipulation, unless a significant delay will result.
    
  • An impacted humeral head fracture may be converted to a displaced humeral head fracture if manipulated.
    

• At least 2 views should be obtained:
  
  • Anteroposterior (AP):
    
    • To visualize dislocation or fracture
      
  • Trans-scapular Y or axillary view:
    
    • To visualize if anterior or posterior
      
• Anterior dislocation:
  
  • Posterolateral compression fracture of the humeral head (Hill–Sachs deformity)
    
  • Corresponding lesion on anterior glenoid rim is the Bankart lesion:
    
    • These do not require treatment.
      
  • Fractures of the greater tuberosity of the humeral head are seen in 15–35%:
    
    • If there is >1 cm displacement after reduction, surgical intervention may be necessary.
      
• Posterior dislocation:
  
  • Often missed on AP film
    
• Degree of overlap on radiographic film is smaller and displaced superiorly, producing the meniscus sign.
  
• Rotated humerus yields “light bulb on a stick” finding on AP view:
  
  • Reverse Hill-Sachs deformity from compression fracture of the anterior medial humeral head may also be seen.
    

• Fracture of the humeral head
  
• Fracture of the humeral shaft
  
• Acromioclavicular injury
  
• Septic shoulder joint
  
• Hemarthrosis in shoulder joint
  
• Scapular fracture
  
• Cervical spine injury
  

TREATMENT

Neurovascular injury should be identified and the arm splinted in the position of most comfort.

• Airway management and resuscitate as indicated.
  
• Exclude more serious injuries, especially in multitrauma patient.
  
• Ensure no injury to axillary nerve or vessels.
  

• Adequate analgesia and muscle relaxation are essential for successful reduction:
  
  • Procedural sedation with a short-acting opioid and a benzodiazepine
    OR
    
  • Methohexital or etomidate alone
    
  • In the cooperative patient, intra-articular block only (20 cc of lidocaine 1% or bupivacaine 0.5%) into shoulder joint
    
• Anterior dislocation reduction techniques:
  
  • Scapular manipulation:
    
    • Patient seated, traction to arm in horizontal plane, countertraction with other hand on clavicle
      
    • 2nd person adducts tip of scapula medially, moving glenoid fossa
      
  • Stimson:
    
    • Patient in prone position with arm dangling over side, hang 10–15 lb around wrist; muscle fatigued over 20–30 min
      
    • Can concurrently use scapular manipulation
      
    • Only 1 person required
      
  • Traction/countertraction:
    
    • Patient in supine position with continuous longitudinal traction to affected arm
      
    • Countertraction from sheet wrapped around chest
      
    • Arm internally or externally rotated if unsuccessful after several minutes
      
  • External rotation:
    
    • Patient supine; elbow at 90°; gentle, slow external rotation of arm
      
    • Should be done slowly and with cooperative patient
      
• Posterior dislocation reduction techniques:
  
  • May use Stimson or traction/countertraction techniques with manipulation of humeral head anteriorly
    
• Inferior dislocation (luxatio erecta) reduction techniques:
  
  • Patient in supine position; gentle longitudinal traction to distract humeral head
    
  • Gentle countertraction with sheet draped over trapezius and chest
    
  • Arm slowly rotated from 180–0°
    
• Postreduction care:
  
  • Postreduction films
    
  • Place in sling and swath or shoulder immobilizer immediately after reduction.
    
  • Shoulder should remain immobilized for 2–3 wk in young patients.
    
  • Immobilization time should be less in older patients to avoid frozen shoulder.
    

• Bupivacaine 0.5%: 20 cc intra-articular to shoulder
  
• Diazepam: 5–10 mg IV (peds: 0.2 mg/kg)
  
• Etomidate: 0.2 mg/kg IV (adult and peds)
  
• Fentanyl: 50–100 μg IV (peds: 2–4 μg/kg)
  
• Lidocaine 1%: 20 cc intra-articular to shoulder
  
• Methohexital: 1–1.5 mg/kg IV (peds: Not routinely used)
  
• Midazolam: 2–5 mg IV (peds: 0.035–0.1 mg/kg)
  
• Morphine: 2–8 mg IV (peds: 0.1 mg/kg); use preservative-free formulation.
  
• Propofol: 1–2 mg/kg IV
  

FOLLOW-UP

• Failure to reduce shoulder may require admission for reduction under general anesthesia or open reduction.
  
• Patients with neurovascular compromise
  

• Patients with successful reductions, confirmed by plain films, may be discharged with shoulder in appropriate immobilizer and with orthopedic follow-up.
  
• Recurrent dislocation may require elective surgery.
  
• Patients with residual neurapraxia from injury or manipulation may be safely discharged with instructions that most symptoms will resolve, but should have neurology follow-up.
  

• Patients with residual neurapraxia should be advised to see a neurologist.
  
• Routine orthopedic consultation should be advised with all successful reductions.
  

Make sure to document sensory exam of axillary nerve prior to reduction.

• Hendey GW. Necessity of radiographs in the emergency department management of shoulder dislocations.
  Ann Emerg Med
  . 2000;36(2):108–113.
  
• Kahn J. The role of post-reduction x-rays after dislocation.
  Acad Emerg Med
  . 2001;8(5):521.
  
• McNamara RM. Reduction of anterior shoulder dislocations by scapular manipulation.
  Ann Emerg Med
  . 1993;22(7):1140–1144.
  
• Perron AD, Ingerski MS, Brady WJ, et al. Acute complications associated with shoulder dislocation at an academic emergency department.
  J Emerg Med
  . 2003;24(2):141–145.
  
• Quillen DM, Wuchner M, Hatch RL. Acute shoulder injuries.
  Am Fam Physician
  . 2004;70(10):1947–1954.
  
• Sileo MJ, Joseph S, Nelson CO, et al. Management of acute glenohumeral dislocations.
  Am J Orthop (Belle Mead NJ)
  . 2009;38(6):282–290.
  
• Ufberg JW, Vilke GM, Chan TC, et al. Anterior shoulder dislocations: Beyond traction-countertraction.
  J Emerg Med
  . 2004;27(3):301–306.
  

CODES