Emergency Central is a collection of disease, drug, and test information including 5-Minute Emergency Medicine Consult, Davis’s Drug, McGraw-Hill Medical’s Diagnosaurus®, Pocket Guide to Diagnostic Tests, and MEDLINE Journals created for emergency medicine professionals. Explore these free sample topics:
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- 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