USMLE Step 2 Clinical Knowledge (CK) Practice Exam

The most common type of shoulder dislocation is anterior dislocation. This occurs when the head of the humerus is displaced forward, usually due to trauma or a fall on an outstretched arm. The mechanism often involves excessive external rotation and abduction of the shoulder.

Anterior dislocations can result from various activities, especially in sports, and are typically associated with certain positions of the arm during injury. Anterior dislocations are more prevalent than posterior, inferior, and superior types due to the anatomical configuration of the shoulder joint and its stability dynamics. The shoulder joint's glenoid fossa is oriented more anteriorly, making the anterior aspect more vulnerable to dislocation.

Recognizing the frequency of anterior dislocations is critical for diagnosis and treatment, as these dislocations require specific management strategies, including reduction and rehabilitation, to restore shoulder function and prevent recurrence. Understanding the common presentation of shoulder dislocations helps in clinical evaluations and guiding appropriate imaging and interventions.