Anterior Glenohumeral Instability Clinical Presentation

Updated: Nov 29, 2015
  • Author: Amin H Afsari, DO; Chief Editor: S Ashfaq Hasan, MD  more...
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Presentation

History

Children presenting with a dislocated shoulder may relate a couple of possible mechanisms. These mechanisms occur in a number of ways and are similar to those in adults. Most commonly, the child falls on the outstretched hand, forcing the arm into abduction and external rotation, levering the humeral head out of the glenoid cavity. Activities promoting this injury include contact sports, falls from heights, fights, and motor vehicle accidents. Other mechanisms have been described, including elevation with external rotation and direct blows.

A history of prior dislocations suggests a high likelihood of anterior glenohumeral instability. Studies have shown a 70-100% recurrence rate in various population groups of patients younger than 20 years.

Next:

Physical Examination

As with physical examinations of any joint, beginning by observing the shoulder is important. Note any atrophy of the biceps, supraspinatus, or infraspinatus. Gross deformities can also suggest the direction of a dislocation.

Range of motion of the shoulder must be tested for restriction or hypermobility. Atraumatic instability generally manifests with hypermobility of the shoulder, whereas traumatic instability typically results in bilaterally symmetric motion. Generalized joint laxity is demonstrated by extending the elbow, wrist, metacarpophalangeal, and distal interphalangeal joints. External rotation can be increased as much as 28° or decreased as much as 14° after dislocation.

Next, the examiner manually assesses translation of the humeral head in the glenoid fossa. The humeral head is grasped in one hand, and the clavicle and scapula are stabilized in the other as the examiner pushes anteriorly and posteriorly. This is known as a shoulder drawer sign. Compared with the unaffected shoulder, the affected shoulder often demonstrates increased laxity. Remember that as much as 50% of posterior translation may be normal.

A sulcus sign is demonstrated by pulling inferiorly on the relaxed shoulder. A sulcus observed between the acromion and proximal humeral head is considered a positive finding. This finding indicates that the shoulder has multidirectional instability.

The key finding in anterior glenohumeral instability is a positive apprehension test. The arm is placed in abduction, extension, and external rotation while being stressed in anterior translation. If the patient becomes apprehensive and reports pain, this is considered a positive finding. It is important to note that pain alone does not constitute a positive apprehension test: The patient must report apprehension.

The relocation test involves placing the shoulder in the position of apprehension and applying a posteriorly directed force on the humeral head. The result is considered positive if this relieves the patient's apprehension.

Impingement signs must also be evaluated because as many as 10% of patients experience impingement after dislocation. Evaluate for the Hawkins sign, and perform the Neer impingement test.

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