Superior labral anterior to posterior lesion / labral tear/
The labrum is a ring of connective tissue in the shoulder. The tendon of the biceps muscle attaches to this ring. In case of a SLAP lesion, the part of the labrum that the biceps tendon attaches to has been torn.
SLAP lesions often occur in overhead athletes due to frequent overhead movement of the arm. In addition, a SLAP lesion can also develop acutely after, for example, falling on a stretched arm.
Description of the condition
The shoulder consists of the shoulder blade (scapula), the upper arm (humerus) and the collarbone (clavicle). The glenoid fossa is part of the shoulder blade. Because the glenoid fossa is very small and shallow in proportion to the humeral head, the labrum is located at the edge of the fossa. This extra edge ensures that the fossa is 50% deeper, so that the humeral head fits better in the fossa. This gives more stability to the shoulder joint.
Different ligaments and muscles attach to the labrum. The most important one is the biceps tendon, which is attached to the labrum at the top. In case of a SLAP lesion, the part of the labrum that the biceps tendon attaches to is torn. This is often the result of the great tensile forces that the biceps muscle can exert on the labrum. If the tear increases in size, a flap can even develop, in which case the labrum is completely detached from the glenoid fossa.
There are different gradations in SLAP lesions:
Degenerative defects (as a result of tissue deterioration) cause some tears in the labrum. In this type, the labrum is still attached to the glenoid fossa.
In type 2, there is a longitudinal tear in the labrum in which the biceps tendon is detached from the glenoid fossa. This can cause a feeling of instability.
In this type, the so-called "bucket handle" tear is present. This means that the longitudinal tear is a flap tear. This flap can move and get stuck between the joint.
The bucket handle tear is larger and runs through the biceps tendon. The biceps tendon is also split in this process.
Cause and origin
Tears in the labrum can develop as a result of degenerative conditions, among other things. This includes, for example, the normal ageing process, which can cause some damage to the tissue. In overhead sports, such as tennis, volleyball and throwing in baseball, this damage can occur earlier.
Because of the position of the shoulder, for instance when throwing, the labrum can also get stuck between the glenoid fossa and the humeral head. When this happens, a tear can occur in the labrum.
Because the tendon of the biceps is attached to the labrum, the labrum is also sensitive to great tensile forces. When the tendon pulls often and hard on the labrum, tears may develop. This can also happen acutely when falling on an extended arm, or falling down. For example, when falling down the stairs when you try to hold yourself up by the railing above you.
Signs & symptoms
In the case of SLAP lesions that develop acutely, a sharp pain can be felt in the shoulder resulting in reduced mobility of the shoulder. The pain is often located deep in the shoulder.
In the case of SLAP lesions that develop gradually, this sharp pain in the shoulder is dependent on movement, but mainly in overhead activities. It can also be felt as if something is jammed when moving above shoulder height.
The most important symptoms of a SLAP lesion are:
- Sharp pain in the shoulder, mostly during overhead movements.
- Feeling as if something is getting stuck in the shoulder.
- Clicking / cracking / snapping sounds.
- Feeling of instability in the shoulder.
- Decreased range of motion of the shoulder.
- Loss of strength in the affected arm.
The treatment of a SLAP lesion can be conservative (without surgery) or surgical. This depends on the severity of the complaints. A treatment plan will be drawn up in consultation with your physiotherapist/orthopaedic surgeon.
The treatment focuses mainly on the instability and functional limitations that result from the complaints. Conservative treatment is preferred where possible. In most cases, the course of treatment therefore consists of conservative treatment first. After a certain period, the effect of the treatment is evaluated.
Initially, conservative treatment consists of properly identifying the cause of the symptoms. This is especially important for problems that did not develop acutely. If the cause is tackled, the chance of recurrence is much smaller. A physiotherapist will look closely at how the entire shoulder complex moves. Which can then be optimised. In addition, exercise therapy is often applied to improve the shoulder stability and to strengthen the attachment of the biceps tendon.
A SLAP lesion type I is usually not operated on. However, if conservative treatment fails, or in the case of types II, III and IV, the decision can be made to proceed with surgery.
Cleland, J. (2007). Orthopaedic clinical examination. An evidence-based approach for physical therapists. Philadelphia: Saunders. Elsevier.
Magee, D.J., Zachazewski, J.E., Quillen, W.S., Manske, R.C. (2016). Pathology and intervention in musculoskeletal rehabilitation. Elsevier, 2nd edition.
Wilk, K.E., Reinold, M.M. & Andrews, J.R. (2009). The atlete's shoulder. Philadelphia: Churchill livingstone. Elsevier.