Reviewed by Dr. Ilya Voloshin, Chief Shoulder and Elbow Division, University of Rochester(Otherwise known as a Labral Tear)
The shoulder is a ball and socket joint. The head of the upper arm bone, or humerus, fits into the shallow cup of the shoulder blade, or glenoid. A rim of soft tissue called the labrum surrounds the glenoid and contributes to the stability of the shoulder. A tear to the labrum called a Bankart lesion usually results when the head of the humerus is forced forward out of the glenoid either fully, as in dislocation, or partially, as in subluxation.
Causes
Usually, injury to the shoulder after a fall on an outstretched hand or collision impact when the arm is in an externally rotated position can cause a Bankart lesion. Rarely, Bankart lesion is present in a loose shoulder with no history of trauma.
Risk Factors
Frequent subluxation or acute dislocations of the humerus from the shoulder joint in the forward direction pose the greatest risks for a Bankart lesion.