What is the most likely type of shoulder dislocation in a patient who has a traumatic event and cannot move the shoulder?

What is the most likely type of shoulder dislocation in a patient who has a traumatic event and cannot move the shoulder?

• A. Anterior
• B. Inferior
• C. Multidirectional
• D. Posterior

Answer: (A)

Traumatic anterior dislocation is most likely. When the shoulder is forcefully abducted and externally rotated, the humeral head tends to slip forward out of the glenoid. This mechanism is the most common cause of shoulder dislocations in adults, and the sudden deformity with the inability to move the arm fits a dislocation scenario. Posterior dislocations usually follow seizures or electric injuries and the arm tends to be held in adduction with internal rotation, not the typical painful, immobile presentation after a direct trauma. Inferior dislocations (luxatio erecta) have the arm held overhead, which is a distinctive but less common pattern. Multidirectional dislocations are usually atraumatic and occur with generalized joint laxity rather than a single traumatic event.

Traumatic anterior dislocation is most likely. When the shoulder is forcefully abducted and externally rotated, the humeral head tends to slip forward out of the glenoid. This mechanism is the most common cause of shoulder dislocations in adults, and the sudden deformity with the inability to move the arm fits a dislocation scenario.

Posterior dislocations usually follow seizures or electric injuries and the arm tends to be held in adduction with internal rotation, not the typical painful, immobile presentation after a direct trauma. Inferior dislocations (luxatio erecta) have the arm held overhead, which is a distinctive but less common pattern. Multidirectional dislocations are usually atraumatic and occur with generalized joint laxity rather than a single traumatic event.