What type of shoulder instability is characterized by a traumatic event resulting in an anterior dislocation?

• A. Unidirectional instabilities
• B. Multidirectional instabilities
• C. Afraid Avoidance Instability
• D. Recurrent instability

Answer: (A)

The type of shoulder instability characterized by a traumatic event leading to an anterior dislocation is classified as unidirectional instability. This condition typically arises when a significant force is applied to the shoulder, resulting in the humeral head dislocating in a specific direction—most commonly anteriorly.

Unidirectional instability is often a direct consequence of trauma, such as a fall or a sports injury, which causes the shoulder ligaments and other supporting structures to stretch or tear, leading to a pattern of instability that predominantly occurs in one direction. After the initial dislocation, the shoulder may be prone to repeated dislocations if the stabilizing structures are compromised.

In contrast, multidirectional instability involves instability in multiple directions, often due to generalized ligamentous laxity rather than a single traumatic event. Afraid Avoidance Instability is not a recognized clinical classification of instability; instead, it describes a psychological response to pain that may limit movement. Recurrent instability refers to the repeated episodes of instability but does not specify the mechanism of injury; it could arise from either unidirectional or multidirectional causes.

Thus, unidirectional instability is the most fitting choice, as it specifically relates to the traumatic event resulting in anterior dislocation of the shoulder.