Scapulothoracic Dissociation

Topic updated on 12/19/14 12:46pm
  • A traumatic disruption of the scapulothoracic articulation often associated with
    • severe neurologic injuries 
    • vascular injuries
    • orthopaedic injuries  
  • Mechanism
    • usually caused by a  lateral traction injury to the shoulder girdle
    • involves significant trauma to heart, chest wall and lungs
  • Associated conditions
    • orthopaedic
      • scapula fractures
      • clavicle fractures
      • AC dislocation/separation
      • sternoclavicular dislocation
      • flail extremity (52%) 
        • the injury results in complete loss of motor and sensory function rendering the extremity non-functional
    • vascular injury
      • subclavian artery most commonly injured
      • axillary artery
    • neurologic injury
      • ipsilateral brachial plexus injury 
      • neurologic injuries more common than vascular injuries
  • Prognosis
    • mortality rate of 10%
    • functional outcome is dependent on neurologic injury   
      • if return of neurological function is unlikely, early amputation is recommended 
  • Scapulothoracic joint
    • a sliding joint
    • articulates with ribs 2-7
    • moves into abduction at 2:1 ratio 
      • GH joint 120° 
      • ST joint 60° 
  • Neurovascular anatomy 
    • brachial plexus 
    • subclavian artery  
    • axillary artery 
  • History
    • history of high energy trauma 
  • Symptoms
    • pain in involved upper extremity (UE)
    • numbness/tingling in involved UE
  • Physical exam
    • inspection
      • significant swelling in shoulder region
      • bruising around shoulder  
    • vascular exam
      • decreased or absent pulses in involved UE
    • neurological exam
      • neurologic deficits in UE
      • neurological status critical part of exam
  • Radiographs
    • required views
      • AP chest
    • recommended view
      • AP and lateral of shoulder as tolerated
      • appropriate images of suspected fracture sites
    • findings
      • laterally displaced scapula 
        • edge of scapula displaced > 1 cm from spinous process as compared to contralateral side 
      • widely displaced clavicle fx 
      • AC separation
      • sternoclavicular dislocation
  • Angiogram
    • indicated to detect injury to subclavian and axillary artery
  • Nonoperative
    • immobilization/supportive care 
      • indications
        • patients without significant vascular injury who are hemodynamically stable
          • patients may have adequate collateral flow to UE even with injury
  • Operative
    • high lateral thoracotomy with vascular repair
      • indications
        • axillary artery injury in hemodynamically unstable patient
    • median sternotomy with vascular repair
      • indications
        • more proximal arterial injury (i.e., subclavian artery) in a hemodynamically unstable patient
    • ORIF of the clavicle or AC joint
      • indications
        • associated clavicle and AC injuries
    • forequarter amputation
      • indications
        • complete brachial plexus injury


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Qbank (3 Questions)

(SBQ12.19) A 25-year-old is involved in a motor vehicle accident and sustains an isolated upper extremity injury. A representative radiograph is shown in Figure A. What physical exam findings are most predictive of functional outcomes?
Topic Review Topic
FIGURES: A          

1. Presence of open fractures
2. Asymmetry of pulses
3. Ecchymosis of the upper shoulder girdle
4. Swelling of the shoulder
5. Neurologic compromise of the extremity

(OBQ10.20) A 30-year-old male sustains a right shoulder injury with initial radiographs shown in Figures A and B. What single piece of additional information would best assist in determining this patient's functional outcome? Topic Review Topic
FIGURES: A   B        

1. Lower extremity injury
2. Neurological deficit
3. Contralateral upper extremity injury
4. Proximal humerus fracture
5. Worker's compensation

(OBQ10.52) A patient presenting with scapulothoracic dissocation and ipsilateral extremity neurologic injury is most likely to have which of the following outcomes? Topic Review Topic

1. Glenohumeral arthritis
2. Return of 3/5 motor strength in distal extremity
3. Full return of extremity sensory function only
4. Flail extremity
5. Death



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