Can you name the key structures in this posterior view of the shoulder?

Below are the major structures of interest labeled in this longitudinal upper chest ultrasound image. 

Image 3: Author’s own image and annotations. 

What is your diagnosis?

This is an anterior shoulder dislocation.

Image 5: Author's own image and annotations.

What are the major structures in this posterior shoulder ultrasound and where is the pathology?

You can see the hyperechoic line of the humeral head sitting deep to the glenoid fossa, indicating an anterior dislocation (the humeral head is farther away from your posteriorly placed ultrasound probe). 

• Pearl: You can see a Hill-Sachs deformity on the humeral head, a common impaction fracture that can occur with dislocations. It is caused by the humeral head hitting the glenoid fossa.