Superior labral antero posterior (slap lesions)
What is Superior Labral Antero Posterior?
SLAP terminology is the abbreviation of the lesion occurring in the Superior Labral Antero Posterior area of the shoulder joint. This can be a cause of pain in the shoulder joint.
Labrum is the cartilage structure surrounding the glenoid rim of the shoulder joint. The glenoid is the dish like cup in the shoulder blade and the head of the arm bone articulates with the glenoid to form the shoulder joint. The glenoid is normally shallow and the fibrocartilagenous structure called labrum is attached around the glenoid to increase its concavity. This confers stability for the shoulder joint. Hence the labrum is located all around the glenoid like a ring. The top part of this ring is called superior labrum. One of the tendon of the biceps muscle gets attached in a broad fashion over the superior labrum. Any lesion occurring from the front of the attachment to the back of the attachment of this biceps tendon on the superior labrum is called Superior Labrum Antero Posterior (SLAP) lesion.
What causes it?
This occurs as a result of injury. A forceful pull of the arm, dislocation of the shoulder joint, falling on an outstretched arm, throwing injury, tackling in spots, weightlifting all can predispose to this. A small lesion occurs initially and if it does not heal, this itself can predispose to further injuries. Extent of tear depends on the severity of the injury. The lesion can vary from simple fraying of the labrum to complete avulsion of the superior labrum with also extension into the front or back of the glenoid.
What are the symptoms/effects?
The features include pain usually with overhead activities, catching, locking or a grinding feel in the shoulder joint, a sense of instability of the shoulder joint, reduced or a painful range of motion and loss of strength of the shoulder joint.
How is it diagnosed?
A thorough history, physical examination with special focus in relation to the SLAP lesion is useful. Some of the special tests whereby putting the biceps in forceful eccentric contraction can reproduce the pain. It is also essential to exclude other conditions that can present in similar way and also to confirm this diagnosis by certain investigations. An X ray of the shoulder joint and a MR Arthrography of the shoulder joint may be useful in confirming the diagnosis. Another better option is by performing arthroscopy of the shoulder joint. In arthroscopy the lesion can be directly visualized and also can be treated at the same time.
What are the treatment options?
When the injury occurs, supportive treatment in the form of pain relieving medications, resting in sling should be done. When the acute pain improves to some extent mobilization as pain allows will help to regain some confidence in the shoulder joint. After the acute phase has settled, often there is possibility of recurrent pain and clicking as mentioned above. An arthroscopic surgery may be needed to treat the problem.