Case #4

Case #2

• Posterior shoulder dislocation
• Acute reverse Hill-Sachs impaction fracture of the anterior humeral head
• Acute minimally displaced reverse Bankart fracture of the posterior glenoid

• Posterior shoulder dislocation with reverse Hill-Sachs and Bankart fractures

• Shoulder dislocations come in three major varieties: anterior, posterior, and inferior, with anterior being by far the most common. Here are some radiographic clues for each type of dislocation:
  • Anterior: humeral head inferior and medial to the glenoid
  • Posterior: humeral head may appear correctly positioned relative to the glenoid on AP view. Shoulder will classically be fixed in internal rotation (the so-called “lightbulb” sign)
  • Inferior: humeral head inferior to the glenoid with the arm often fixed in abduction (raised over the head, aka “luxatio erecta”)
• Associated fractures:
  • Hill-Sachs
    • Occurs along the posterolateral humeral head where the humeral head impacts on the glenoid
    • Best seen on internal rotation views
    • Reverse Hill-Sachs from posterior dislocation -> impaction fracture of the inferomedial humeral head, which results in a “trough” sign on radiographs
  • Bankart
    • Anterior rim of the glenoid, often difficult to see on radiographs
    • Reverse Bankart (posterior rim) with posterior shoulder dislocation

Images