Case 20 Answer

Answer: posterior shoulder dislocation (see axillary below)

Clues:

1) both views look the same (internally rotated)

2) light bulb sign (humeral head looks like a light bulb)

3) loss of the normal half-moon overlap of the humeral head and the glenoid

4) irrregular posterior glenoid cortex c/w reverse “bony” Bankart

5) borderline “Rim sign” - widened glenohumeral distance (diagnostic is over 6mm, which this may be just under)

reference: https://radiopaedia.org/articles/posterior-shoulder-dislocation