Causes / typical injury mechanism / pathophysiology: Anterior dislocations are the most common direction of shoulder dislocation, comprising up to 97% of shoulder instability cases. They are generally caused by an impact to an abducted and externally rotated arm. Abduction and external rotation forces, which result in shoulder dislocation, cause an anterior and inferior glenoid labrum avulsion tear and disruption of the anterior band of the inferior glenohumeral ligament, which is called a Bankart lesion. When the anterior inferior portion of the glenoid cavity of the scapula bone is fractured, this is called a "bony Bankart."

Classic history and presentation: The general presentation of shoulder dislocations is exquisite pain at the shoulder joint, a history of shoulder trauma, and limited motion of the shoulder. There will be a loss of the smoothness or roundness of the appearance of the affected shoulder, and a prominent acromion may be visible.

Prevalence: The shoulder is the most commonly dislocated joint in the body. There is a propensity for this injury to occur in teenagers and young athletes, with a high rate of recurrence if not managed surgically.

Risk factors:

• Male gender
• Participation in contact sports
• Young age at time of initial injury or dislocation