Turkel et al8 demonstrated that the anterior band of the inferior glenohumeral ligament is the primary restraint to anterior gleno-humeral translation, especially with the arm in an abducted position. Anterior dislocation usually results from an indirect force with the arm in the abducted, externally rotated position. In this position, the anterior band of the inferior glenohumeral ligament is tensioned across the front of the glenoid. This checkrein, in conjunction with the glenoid labrum, normally prevents further anterior translation of the humeral head. With sufficient force, however, the anterior band of the inferior glenohumeral ligament traumatically fails, and the humerus is levered over the anterior glenoid rim resulting in dislocation. This capsulolabral injury, the Bankart or Perthes lesion, is the salient pathoanatomic feature of anterior instability and is seen in a very high percentage of traumatic shoulder dislocations.9-13
In addition to the anteroinferior lesion, the injury may extend superiorly into the labral attachment of the biceps tendon producing a concomitant superior labrum anterior posterior (SLAP) lesion as described by Snyder et al.14 Another injury variant is the detachment laterally of the inferior glenohumeral ligament from the humeral neck, a humeral avulsion of glenohumeral ligament lesion, as described by Bach et al15 and subsequently by Wolf et al.16
A traumatic humeral dislocation typically results in postero-lateral humeral head compression against the bony glenoid rim. This produces the classic Hill-Sachs lesion, a chondral or osteochondral compression fracture. Arthroscopically, this lesion can be differentiated from the normal, nonarticular "bare area" of the humeral head by the appearance of articular cartilage on both sides of the lesion. Arthroscopically, the acute Hill-Sachs lesion will have an irregular appearance with bleeding, exposed cancellous bone (Fig. 18-3). A large Hill-Sachs lesion may engage the anterior glenoid with humeral abduction and external rotation and produce a subjective clunk and a sensation of gleno-humeral dislocation.
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Everything you wanted to know about. How To Cure Tennis Elbow. Are you an athlete who suffers from tennis elbow? Contrary to popular opinion, most people who suffer from tennis elbow do not even play tennis. They get this condition, which is a torn tendon in the elbow, from the strain of using the same motions with the arm, repeatedly. If you have tennis elbow, you understand how the pain can disrupt your day.