Dear Sports Doc, I have been told that my son, who plays baseball, has a SLAP tear in his shoulder. What exactly is a SLAP tear? Does it require surgery to repair?
First described by Dr. James Andrews in the mid 1980s, a SLAP tear is an acronym that refers to a Superior Labrum Anterior to Posterior tear.
As shown in Figure 1, in a healthy shoulder an oval-shaped socket called a glenoid is surrounded by a layer of bumper-like tissue known as the labrum. Along the lower and inferior parts of the labrum, the shoulder capsule attaches to the labrum.
This tissue is the critical structure that provides stability to the shoulder joint. During shoulder dislocations, the lower parts of the labrum will typically separate from the socket and create looseness in the joint. This can lead to more dislocation events.
The anatomy and mechanics of the shoulder are complex. Along the upper aspect of the socket, the labrum also is the origin of the tendon that runs along the long head of the biceps. The cord- like tendon then travels underneath the rotator cuff, exiting the shoulder joint and traveling down the arm. This tendon turns into the large biceps muscle we can all see in the arm and attaches to the radius bone just below the elbow joint.
HOW DO SLAP INJURIES OCCUR?
Some SLAP injuries occur as a result of direct trauma. Dislocation events can cause tears of the inferior labrum and, at times, these can extend upwards into the biceps origin point.
More commonly, SLAP tears are the result of gradual attrition and degenerative changes in the shoulder. It is particularly common in overhead athletes, those who participate in sports activity where the upper arm and shoulder arc over the head. This includes pitchers, swimmers and volleyball players.
The reetitive overhead movement of the arm can result in subtle changes in mechanics, which place undue force across the superior labrum. When this happens, the superior labrum will peel off the socket and become detached. An example of peel-back is showing in Figure 2.
In older patients, both the rotator cuff and superior labrum can undergo degeneration over time. This can be the result of diminished blood flow to the area, which can result in gradual wear and tear to the biceps attachment point. In many patients undergoing surgery for rotator cuff tears, it is not uncommon to also see problems in the SLAP region. These often are addressed simultaneously.
SLAP tears are usually diagnosed with an MRI arthrogram. This type of test consists of an MRI performed after an injection of dye into the joint. The dye is very helpful in outlining the labrum and makes the MRI much more sensitive when diagnosing labral tears.
Many patients ask if surgery is required to correct a SLAP tear. The answer is that it is not always necessary. Many patients do well with nonoperative management for a SLAP tear. The need for surgery should be driven by a patient’s symptoms. Often, noninvasive treatment protocols are a viable option and can improve pain and function.
In overhead athletes, good evidence shows that by correcting the issues related to improper mechanics with physical therapy, many patients can have good pain relief and experience a full return to their sport.
In cases where the SLAP tear is causing excessive pain, a steroid injection directed into the area of the tear can provide pain relief and allow time for physical therapy and activity modification to have their desired effects. It is important to note there is no evidence that an isolated SLAP tear will lead to further damage in the shoulder if left untreated.
In very rare cases, SLAP tears can be associated with a benign cyst that forms on the back side of the tear. These cysts are known as spinoglenoid notch cysts. Unfortunately these cysts grow right next to one of the important nerves in the shoulder. By compressing the nerve, they can cause weakness in the shoulder. Typically, these symptoms will not resolve without removal and treatment of the cyst, and early surgical management is usually recommended. See Figure 3 for details.
If physical therapy and other treatment protocols aren’t working, there are several surgical treatment options for SLAP tears. Each has been shown to have the potential to improve pain and allow patients to return to their prior level of activity. The best choice differs from patient to patient and should always be best discussed with a surgeon.
One of the earliest described treatments for SLAP tears is surgical repair of the lesion. This is known as SLAP repair. This procedure is done arthroscopically and involves placement of absorbable anchors into the top of the socket through which sutures are placed. These sutures are used to reattach the torn labrum to the top of the socket. Recovery and rehabilitation protocols vary, but typically it takes four to six months to return to sports following this procedure.
As more SLAP repairs have occurred over time, it has become clear that for some patients SLAP repair can result in continued pain or loss of motion in the shoulder. As a result, some surgeons will recommend a procedure known as a biceps tenodesis as an alternative to SLAP repair.
In older patients and patients who are not elite-level overhead athletes, this pro- cedure has been shown to have equally good results with fewer complications than the traditional SLAP repair. Biceps tenodesis involves surgically releasing the long head of the biceps tendon from the superior labrum. This will remove the tension from the SLAP tear, which is thought to be the primary source of pain. The biceps is then reattached outside the shoulder joint to the humerus bone via either an arthroscopic technique or a small open incision.
Although this procedure is somewhat controversial, to date it is not thought that moving the biceps to a position outside the shoulder joint changes the biomechanics of the shoulder or has any long-term effects on the shoulder.
There is a wide spectrum of treatment options to consider. As with any injury or medical condition, every case and every patient is different, so it is important to consult with a surgeon.