J sign (shoulder)

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The J sign refers to the appearance of the inferior glenohumeral ligament in the presence of humeral avulsion of the glenohumeral ligament (HAGL lesion ) as well as in the less common glenoid avulsion of the glenohumeral ligament (GAGL lesion).

Radiographic features

MRI

The normal U-shaped inferior glenohumeral recess is retracted away from the humerus, appearing in the shape of "J" in the right shoulder, or reversed "J" in the left shoulder in coronal oblique views in HAGL lesion , and reverse of this for GAGL lesions .