|Classification and external resources|
Glenoid fossa of right side. (Glenoidal labrum labeled as "glenoid lig.")
A SLAP tear or SLAP lesion is an injury to the Glenoid labrum (fibrocartilaginous rim attached around the margin of the glenoid cavity). SLAP is an acronym for "superior labral tear from anterior to posterior".
The shoulder joint is a 'ball and socket' joint. However, the 'socket' (the glenoid fossa of the scapula) is small, covering at most only a third of the 'ball' (the head of the humerus). It is deepened by a circumferential rim of fibrocartilage, the glenoidal labrum. Previously there was debate as to whether the labrum was fibrocartilaginous as opposed to hyaline cartilage found in the remainder of the glenoid fossa. Previously, it was considered a redundant, evolutionary remnant, but is now considered integral to shoulder stability. Most agree that the proximal tendon of the long head of the biceps brachii muscle becomes fibrocartilaginous prior to attaching to the superior aspect of the glenoid. The long head of the triceps brachii inserts inferiorly, similarly. Together, all of those cartilaginous extensions are termed the 'glenoid labrum'.
A SLAP tear or lesion occurs when there is damage to the superior (uppermost) area of the labrum. These lesions have come into public awareness because of their frequency in athletes involved in overhead and throwing activities in turn relating to relatively recent description of labral injuries in throwing athletes, and initial definitions of the 4 (major) SLAP sub-types, all happening since the 1990s. The identification and treatment of these injuries continues to evolve.
- Type I. Degenerative fraying of the superior portion of the labrum, with the labrum remaining firmly attached to the glenoid rim
- Type II. Separation of the superior portion of the glenoid labrum and tendon of the biceps brachii muscle from the glenoid rim
- Type III. Bucket-handle tears of the superior portion of the labrum without involvement of the biceps brachii (long head) attachment
- Type IV. Bucket-handle tears of the superior portion of the labrum extending into the biceps tendon
- Type V. Anteroinferior Bankart lesion that extends upward to include a separation of the biceps tendon
- Type VI. Unstable radial flap tears associated with separation of the biceps anchor
- Type VII. Anterior extension of the SLAP lesion beneath the middle glenohumeral ligament
Several symptoms are common but not specific:
- Dull, throbbing, ache in the joint which can be brought on by very strenuous exertion or simple household chores.
- Difficulty sleeping due to shoulder discomfort. The SLAP lesion decreases the stability of the joint which, when combined with lying in bed, causes the shoulder to drop.
- For an athlete involved in a throwing sport such as baseball, pain and a catching feeling are prevalent. Throwing athletes may also complain of a loss of strength or significant decreased velocity in throwing.
- Any applied force overhead or pushing directly into the shoulder can result in impingement and catching sensations.
Few with SLAP lesion injuries return to full capability without surgical intervention. In some, physical therapy can strengthen the supporting muscles in the shoulder joint to the point of reestablishing stability. For most others, the choice is to do nothing or some form of surgical repair.
Associated findings within the shoulder joint are varied, may not be predictable and include:
- SLAP lesion – labrum/glenoid separation at the tendon of the biceps muscle
- Bankart lesion – labrum/glenoid separation at the inferior glenohumeral ligament
- Biceps Tendon - exclusion of pulley injury
- Bone – glenoid, humerus — injury or degenerative change involving joint surface
- Anatomical variants — sublabral foramen, Buford Complex
It should be noted that while good outcomes with SLAP repair over the age of 40 are reported, both age greater than 40 and Workmen's Compensation status have been noted as independent predictors of surgical complications. This is particularly so if there is an 