Scapulothoracic Dissociation: A Guide to This Rare Scapulothoracic Injury

Scapulothoracic Dissociation

1. This injury is a traumatic disruption of the scapula from the posterior chest wall.
2. This rare, life-threatening injury is essentially a subcutaneous fore-quarter amputation.
3. The mechanism is a violent traction and rotation force, usually as a result of a motor vehicle or motorcycle accident.
4. Neurovascular injury is common: 1. Complete brachial plexopathy: 80%
5. Partial plexopathy: 15%
6. Subclavian or axillary artery: 88%
7. It can be associated with fracture or dislocation about the shoulder or without obvious bone injury.
8. Diagnosis includes: 1. Massive swelling of shoulder region
9. A pulseless arm
10. A complete or partial neurologic deficit
11. Lateral displacement of the scapula on a nonrotated chest radiograph, which is diagnostic ( Fig. 13.7 )
    
    
12. Classification ## Type I: Musculoskeletal injury alone

Type IIA: Musculoskeletal injury with vascular disruption

Type IIB: Musculoskeletal injury with neurologic impairment

Type III: Musculoskeletal injury with both neurologic and vascular injury

1. Initial treatment 1. Patients are often polytraumatized.
2. Advanced trauma life support protocols should be followed.
3. Angiography of the limb with vascular repair and exploration of brachial plexus are performed
   as indicated.
4. Stabilization of associated bone or joint injuries is indicated.
5. Later treatment 1. Neurologic
6. At 3 weeks, electromyography is indicated.
7. At 6 weeks, cervical myelography or magnetic resonance imaging (MRI) is performed.
8. Shoulder arthrodesis and/or above elbow amputation may be necessary if the limb is flail.
9. Nerve root avulsions and complete deficits have a poor prognosis.
10. Partial plexus injuries have good prognosis, and functional use of the extremity is often regained.
11. MRI—“empty sleeve sign”
12. Osseous
13. If initial exploration of the brachial plexus reveals a severe injury, primary above elbow amputation should be considered.
14. If cervical myelography reveals three or more pseudomeningoceles, the prognosis is similarly
    poor.
15. This injury is associated with a poor outcome including flail extremity in 52%, early amputation in 21%, and death in 10%.

Intrathoracic Dislocation of the Scapula

1. This is extremely rare.
2. The inferior angle of the scapula is locked in the intercostal space.
3. Chest computed tomography may be needed to confirm the diagnosis.
4. Treatment consists of closed reduction and immobilization with a sling and swathe for 2 weeks, followed by progressive functional use of the shoulder and arm.