A labrum tear in the shoulder (glenoid labrum) can result in an unstable shoulder. Among its most important functions, the glenoid labrum creates a bumper cushion that deepens the entire shoulder socket (glenoid) to better match the curvature of the humeral head. This deepening of the socket increases the amount of energy required for the ball (humeral head) to jump out of the socket (glenoid). The shoulder is a circle so the glenoid labrum can be injured or damaged anywhere and everywhere along the entire circle depending on the mechanism of injury and also the number of episodes of injury involved. For instance, we know that the more episodes the shoulder joint has of jumping out of socket the more extensive the injury to the glenoid labrum and remaining shoulder tissues. This may also be why the risk of developing shoulder arthritis also increases the longer the shoulder is unstable. Diagnosing a glenoid labrum tear can also be difficult-many studies have confirmed that no one test on clinical exam is very accurate for labrum tears. Many patients may also only present with nondescript pain without a feeling of the shoulder being unstable. A glenoid labrum tear can also contribute to suprascapular nerve pathology (pinched nerve in shoulder). Also, because the shoulder is a circle, stretching or tearing on one side of the joint means there is almost always injury on the opposite side as well. An MRI by itself is also not very reliable to make this diagnosis. An MRI arthrogram- this test involves injecting fluid into the shoulder joint to help distend the joint followed by an MRI scan – is able to provide contrast enhancement for better detail of the labrum and surrounding tissues to increase the diagnostic accuracy (around 90%).
Labrum tears in Zone A are called SLAP (Superior Labrum Anterior Posterior) Tears.
This is the zone where the biceps tendon (long head) also inserts so tears involving this area may include pain and/or pathology of the biceps tendon. There are several different types/patterns of SLAP tears. Although, four different types of SLAP tears are the most familiar to surgeons, the increasing recognition that labrum tears can occur anywhere and everywhere along the entire circle has resulted in up to ten distinctly different types of SLAP tears where a Type IX SLAP tear means that the labrum is torn completely around the entire circle. Labrum tears in Zone B are often referred to as Bankart Tears or Bankart Lesions. Labrum tears in Zone C are typically called posterior labrum tears. Shoulder arthroscopy is the gold standard for the diagnosis and treatment of labrum tears. With the great advancements in techniques and instrumentation shoulder arthroscopy is offered by many orthopedic surgeons with widely varying levels of skills and success. The best labrum repairs require a technique that fully recognizes that for every patient, the surgeon must be fully comfortable and prepared to evaluate and treat the entire shoulder globally. For the best outcomes, we recommend an evaluation with an experienced shoulder specialist that routinely performs these repairs.
|Type II SLAP Lesion||Repaired Type II SLAP Lesion|
|Repaired Type IX SLAP Lesion||The Circle Concept|