Differential Diagnosis: Review of the GLAD Lesion (Glenolabral Articular Disruption)
The GLAD lesion, or glenolabral articular disruption (GLAD) lesion, is a superficial tear of the anteroinferior labrum in combination with an articular cartilage lesion of the anterior inferior quadrant of the glenoid. The injury is thought to result from glenohumeral impaction while the arm is abducted and externally rotated.
The labral component of the abnormality typically represents an inferior based flap tear without evidence of capsulo-periosteal stripping. Since the anterior fibers of the inferior glenohumeral ligament (IGHL) remain strongly attached to the labrum and glenoid, the GLAD lesion is usually not associated with anterior instability.
Persistent anterior shoulder pain after a fall onto an outstretched arm is the most common clinical presentation. There are no signs of clinical or surgical anterior instability.
The degree of articular cartilage damage is variable and ranges from softening and fibrillation to deep surface defects with loose fragments of cartilage which might remain attached to the anterior labrum and can be undermined by contrast media on MR arthrography. Particularly if the chondral lesion is small and therefore hardly visible on MR imaging, the GLAD lesion can look similar to instability-related labral injuries. It is therefore important to note that the labrum is nondisplaced and both the IGHL as well as the periosteum are intact.
Arthroscopic debridement has been proposed as the treatment of choice.