The young male had an electrocution to the left upper limb. Electrocution is a cause of posterior shoulder dislocation. Clinically there was no dislocation at the time of presentation to an orthopedic surgeon. Patient denies the history of dislocation. 

Ultrasound shows intact rotator cuff. However, there is a defect in anteromedial aspect of the humeral head; deep to subscapularis tendon. It is an impaction fracture due to posterior dislocation which must have been transient at the time of injury.