The glenoid labrum is an integral component in the stabilization of the head of the humerus within the glenoid fossa of the scapula (glenohumeral joint, primary shoulder joint). Because the glenoid fossa is fairly shallow, the labrum surrounds the fossa to deepen the pocket with which the humerus articulates.
The labrum is a thin piece of dense fibrocartilage. Labrum is utilized in both the glenohumeral and ischiofemoral (hip) joints to deepen the articulating surface of the joints. Labrum is inelastic (does not stretch) and so is well suited to withstand the normal forces placed upon the structure.
However, if the external force is greater than the tensile force of the labrum, a tear can occur. An example of this type of force is that which is involved in an anterior dislocation of the humerus.
Bankart Lesion
If the external force is great enough to dislocate the humerus from the glenoid fossa, the labrum is first structure that can be torn as the humerus slides forward and out of the joint. This type of tear is called a Bankart lesion (Foundations of Athletic Training, 2009).
Because the inferior glenohumeral ligament and capsule are attached to the labrum at the glenoid, these structures can also be damaged or torn as the humerus moves anteriorly. Tearing these structures leaves the glenohumeral at risk for anterior instability (recurrent anterior dislocations).
SLAP Lesion
A second type of injury to the glenoid labrum is known as a SLAP lesion, tear of the superior labrum anterior to posterior. Because of the attachment of the long head of the biceps to the superior glenoid, this type of injury can also disrupt the attachment of the biceps tendon (Foundations of Athletic Training, 2009).
Depending on the location and size of the tear, a “flap” tear may also occur. In this instance, the torn piece of labrum folds over into the joint. This type of injury would cause more pain and disability for the individual.
Signs and Symptoms of a Glenoid Labrum Tear
The primary symptom of a labrum tear is an associated “clicking,” “popping,” or “catching” deep within the joint. These symptoms tend to occur when the arm is raised and externally rotated.
If the tear was the result of an anterior dislocation, the patient may also present with anterior instability. The patient may state that the shoulder feels “unstable” or that the humerus “shifts” or moves anteriorly during certain motions.
In a throwing athlete, the athlete may complain of pain just after the ball is thrown. This occurs because the force of the muscles needed to accelerate the arm continues to move the head of the humerus in an anterior direction just after the ball is released because the anterior stabilizing structures are damaged.
The athlete may also complain of a “dead” arm after throwing. Weakness is also a primary symptom of a labrum tear.
Although there are several special tests to diagnose a torn glenoid labrum, most orthopedic surgeons will request and MRI. An MRI will differentiate a torn labrum from other injured or damaged soft tissue structures within the joint.
Treatment for a Glenoid Labrum Tear
Treatment options will depend on the location and size of the tear, the presence of associated instability, and the activity level of the patient.
Initial treatment may include rest, anti-inflammatory medication, and rehabilitation exercises. Most labral tears will heal without surgical repair. However, if pain does not diminish with rehabilitation, the tear is associated with a biceps tendon tear, or there is instability associated with the injury, then operative repair may be indicated.
According to Damian Williams’ article The Labral Tear – Shoulder (May 4, 2008), most labral tears that need surgical repair will only need arthroscopic debridement (removal of abnormal, damaged, or excess tissue). An open procedure may be indicated if the tear is too large for arthroscopic repair or if there is associated instability.
Terry Zeigler - Educating through writing with over twenty-five years of experience as a Kinesiology Professor and Certified Athletic Trainer.
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