2. A 25yo male complains of shoulder pain after falling forward on his outstretched hand after leaving a club. On exam, he holds his right arm internally rotated and adducted

3. Light bulb sign: Humeral head looks rounded on AP view and posterior to the glenoid fossa on axillary view Empty glenoid sign: Increased distance between the articular surface of humeral head and anterior glenoid Normal range: 0-6mm Through defect: Curved dense line, indicating impaction fracture of the antero-medial surface of the humeral head

4. Closed reduction Operative repair if closed reduction unsuccessful Immobilization Place in sling and swath Obtain post reduction film Physical therapy and early mobilization to prevent frozen shoulder Ortho follow up Prognosis if often excellent if detected early but very susceptible to reinjury and repeated dislocations if detected late

5. History typically of axial load to the adducted and internally rotated arm (fall on outstretched arm or blow to the front of shoulder Although the mechanism of fall on outstretched arm is more common, test questions will often use a pt presenting after a seizure or electrical shock Only 20% abduction needed to obtain axillary view, but if unable to obtain, use a scapular Y view Associated with Detachment of posterior glenoid labrum (reverse Bankhart) Defect of the anteromedial aspect of the humeral head (reverse Hill-Sachs) Fractures of the humeral tuberosities, shaft, and/or humeral neck.

9. Marx J MD; Hockberger R MD; Walls R MD. Rosen’s emergency medicine. 7 th ed. Simon R; Sherman S; Koenigsknecht S. Emergency orthopedics: the extremities. 5 th ed. McGraw Hill Publishing. Wheeless C R III MD. Wheeless textbook of orthopedics. www.wheelessonline.com.