Glenoid labrum tear is a split in the fibrocartilaginous structure surrounding the glenoid, also known as the shoulder joint socket. The tear can be caused by injuries like direct a fall on the shoulder or recurrent overhead raising of the shoulder as in pitching. It can involve either the superior, anterior or posterior part of the labrum. Manifestations include pain and restriction of shoulder mobility. History, clinical examination, and imaging studies are performed to confirm the diagnosis.
The socket of the shoulder joint is lined by a fibrocartilage which is known as the glenoid labrum. Chronic shoulder movements such as raising the hand above the head as done by baseball pitchers and weight lifters or a direct injury with fall on an outstretched arm can result in a glenoid labrum tear.
Patients present clinically with shoulder pain while raising the arm above the head, a sensation of shoulder joint instability, locking or popping or grinding of the joint, nocturnal shoulder pain with diminished strength. In the case of superior labral tears, patients complain of posterior shoulder pain with a sensation of popping and clicking.
A superior labral tear from anterior to posterior is called a SLAP tear and can manifest as pain in the posterior part of the shoulder during abduction and external rotation, with the patient becoming fatigued easily during throwing movements. Dead arm syndrome comprises of all these symptoms. A tear of the anteroinferior part of the glenoid labrum can cause glenolabral articular disruption (GLAD) with avulsion of the articular cartilage.
During a physical examination, several tests  devised to assess shoulder mobility are employed e.g. Speed's test, Jobe's test, O'Brien or active compression test   , anterior slide test , biceps tension test I , and biceps tension test II .These are especially important in athletes as their ability to internally rotate the shoulder during abduction is affected and they are therefore at risk of developing a dead arm syndrome . In an anterior type II SLAP tear, the Speed's and O'Brien test are positive while the Jobe's test is positive in posterior type II SLAP tears . However, none of these tests have been found to be very reliable  . Approximately 40% patients with SLAP lesions are also likely to suffer from rotator cuff tears and therefore, signs of rotator cuff impingement should be looked for  in patients with glenoid labrum tears.
A glenoid labrum tear can be diagnosed after obtaining a detailed patient history, performing a clinical examination of the shoulder joint and neck followed by imaging studies. Specific inquiry about the activities should be made as the patient may be using the shoulder for repeated overhead shoulder movements such as pitching or weightlifting.
Imaging studies such as plain X-rays of the shoulder, ultrasonography, computed tomography (CT) scan, magnetic resonance imaging (MRI) and CT arthrography can help in the diagnosis  , although contrast- enhanced MRI is the gold standard test used for confirmation. Plain X-rays of the shoulder may reveal associated fractures while ultrasonography is very sensitive in detecting labral tears and is useful for the preoperative evaluation of patients with an anterior instability of the shoulder joint.
Based on findings of arthrotomography, labral tears have been classified as :
Grade I: simple tears within the labrum or at the labrum-glenoid cartilage junction
Grade II: complete segmental tear
Grade III: labral tear associated with a fracture of the bony rim of the glenoid.
Other imaging findings in glenoid labral tears include paralabral cysts (in SLAP tears), and fluid in the suprascapular notch with nerve compression.