Posterior Bankart Tear

Posterior shoulder instability typically results from a dislocation injury to the shoulder joint when the humeral head (ball) of the humerus (upper arm bone) is displaced from its normal position in the center of the glenoid (socket) and the joint surfaces no longer touch each other. The most common dislocation is anterior (more than 90 percent), where the humeral head is in front and below the glenoid. With falls on an outstretched hand in front of the body, a posterior shoulder dislocation can occur.