What is a dislocated shoulder?

• A. The shoulder joint comes out of place
• B. A fracture of the clavicle
• C. A sprain of the AC joint
• D. A rotator cuff tear

Answer: (A)

A dislocated shoulder means the ball of the upper arm bone has moved out of its socket in the shoulder blade, so the joint surfaces are no longer aligned. That loss of alignment is the defining feature: the humeral head has slipped from the glenoid fossa, often with visible deformity, intense pain, and an inability to move the arm.

This is different from a fracture of the clavicle, which is a break in the collarbone itself and presents with pain and swelling along the collarbone area, not a displaced shoulder joint. A sprain of the AC joint injures the ligaments where the collarbone meets the shoulder blade, causing pain and possibly a separation at the top of the shoulder, but the ball stays in the socket. A rotator cuff tear involves torn tendons around the joint, leading to weakness and pain with lifting, not a dislocated joint.

If a shoulder is dislocated, it’s an emergency requiring medical evaluation and reduction by a clinician, along with ensuring blood flow and nerve function are intact.