Superior Labral Tear (SLAP Tear)

The labrum is a fibrocartilaginous tissue that circles the peripheral rim of the glenoid (socket of the shoulder). The labrum functions as the attachment site of the shoulder capsule, the ligaments that run between the humeral head (ball) and glenoid (socket) of the shoulder to provide stability. The long head of the biceps tendon also attaches to the superior (upper) bony glenoid by its attachment through the superior (upper) labrum. Injury to the superior labrum is referred to as a SLAP lesion (tear), which stands for Superior Labrum, Anterior to Posterior (front to back). This tear may take the form of degenerative (wear and tear) fraying, a split in the labrum, or a complete separation of the labrum off the bony glenoid, with or without damage to the biceps tendon attachment. Superior labral separations also result in some lesser amounts of shoulder instability. Superior labral tears are sometimes difficult to see on MRI and are sometimes only found during arthroscopic surgery.