• Causes: electrocution and seizures
  • Findings

–Trough sign: vertical compression fx of anteromedial humeral head

–Rim sign: widening of glenohumeral joint > 6 mm

–Absent crescent sign: separation of humerus from glenoid such that normal overlap is lost

–Humerus fixed in internal rotation

  • If suspected, get transscapular Y view (axillary view OK, but painful and may dislocate a spontaneously relocated shoulder)

–Humeral head lies posterior to glenoid, center of the “Y”

  • CT: evaluate complications such as reverse Hill Sachs or reverse Bankart, stripping of posterior periosteum, tear of posterior labrum

Anterior Shoulder Dislocation