shoulder dislocation CHORUS

Description: * anterior (subcoracoid)
  o humerus --> beneath coracoid process, anterior to glenoid
  o most frequent site + type of dislocation of any joint
  o easily detected
  o repeated dislocation ==> Hill-Sachs deformity and/or Bankart deformity
* posterior
  o 2 - 4% of shoulder dislocations
  o 50% d/t seizures; trauma, electrical shock
  o often missed on AP view: use "Y" or axillary view
  o "rim" sign in acute dislocation
   + increased glenohumeral space (normal 6 mm --> widened to 14 mm)
  o +/- compression fx of anterior surface of humeral head
* 20% ==> associated fx