Traumatic detachment of the glenoid labrum. This lesion is seen in over 85% of cases after a traumatic anterior dislocation. The inferior gleno-humeral ligament, which is attached medially to the inferior half of the anterior glenoid labrum, is the most important of the ligaments that stabilise the shoulder. At the time of the original injury, the humeral head, when it is forced out anteriorly and inferiorly, first stretches the anterior capsule and the inferior glenohumeral ligament. Then, as a result of traction, the fibrous labrum is pulled off from the inferior half of the anterior rim of the glenoid.
Bankart saw recidivation of the shoulder joint as an unusual condition affecting epileptics and athletes, above all football, reporting only 27 cases during the years 1923 to 1938.