A SLAP lesion stands for a Superior Labrum Anterior to Posterior injury in the shoulder. To accurately understand what a SLAP lesion is, you first need to understand the normal anatomy of the shoulder. The shoulder joint is made up of a ball (or the humeral head) and the socket (or the glenoid). The ball is a very large structure, and the glenoid is very small and flat. Because of this, there is a large range of instability. To provide stability of the shoulder, there is a labrum (or a “bumper pad”) that surrounds the socket in 360 degrees.
Common Injuries to the Labrum
Injuries to the labrum can occur at a variety of locations. An injury to the anterior labrum (or the front labrum) occurs if a shoulder dislocates. This is commonly treated surgically to prevent any further dislocation. Injury to the posterior, (or back labrum) can occur with dislocation or more commonly with a repetitive force of the shoulder, such as weightlifting. If torn, The posterior labrum can cause pain, and it is common to treat it surgically.
The superior labrum is the top labrum. If you imagine the socket being like a face on the clock, the superior labrum extends from approximately 11 o’clock to the 1 o’clock position part. A superior labrum injury can extend from posterior or 11 o’clock to anterior 1 o’clock or vice versa. What is unique to the superior labrum is that one of the two biceps tendons attaches directly to the superior labrum and can cause a traction force if the biceps are activated.
Very little was known about superior labral injuries until the late 1980s when they were first described by Dr. Jimmy Andrews. He described these as occurring in the throwing athlete. It was felt that the traction or the pressure from the biceps when it is activated would pull on the superior labrum and cause injury. Superior labral injuries are commonly seen in repetitive overhead throwers.
Another mechanism for superior labral injury can be a fall on an outstretched arm causing a compression force to the ball and socket, or sudden traction on the arm. The three most common mechanisms we see at Advanced Orthopaedics for superior labral injuries that occur in the repetitive thrower, the fall on the outstretched arm, as well as a sudden distraction injury to the arm.
What are the different types of SLAP tears?
There are multitudes of different types of SLAP tears. In a very simple fashion, some can be a degenerative tear where the superior labrum is frayed, but there is no detachment of the labrum from the socket and no involvement of the biceps tendon. There also can be a tear of the superior labrum, which is completely detached from the socket and also can be a tear of the superior labrum, which extends into the biceps tendon.
What are the symptoms of a superior labral tear?
Typically the patient will complain of a “popping sensation” to the shoulder as well as have a vague pain with any range of motion of the shoulder, most notably overhead activity. These patients typically complain of chronic pain, which they felt would get better with rest and anti-inflammatories, but their symptoms persist.
How is this diagnosed?
SLAP tears are not seen on x-rays. They are soft tissue injuries, and the x-ray shows only bone. They can be seen on MRIs. MRIs are historic for having a high “false-positive rate,” as well as a high “false-negative rate” for superior labral injuries. This means that the MRI says that there is a tear when in fact there is not or vice versa. If the orthopaedic surgeon is concerned about a superior labral tear, it is best to get an MRI with dye called an arthrogram MRI. At Advanced Orthopaedic Specialists, we feel the best way to determine a true diagnosis of SLAP tear is with a physical exam. There are tests we use that can isolate the superior labrum and give us a good indication if the superior labrum is torn.
How will I treat the superior labrum?
Superior labrum injuries are very common and rarely in and by themselves require surgery. At Advanced Orthopaedic Specialists, we start with physical therapy, anti-inflammatories, and a good rotator cuff strengthening program. If this fails, we have had excellent success with injections into the joint under ultrasound with either cortisone or platelet-rich plasma. If the symptoms persist, this can be addressed surgically. Dependent on the type of tear which is present, this will dictate which surgical technique is performed. If there is a fraying of the labrum but an intact biceps attachment, this is debrided with excellent results. The patient wears a sling for a week and returns to overhead activity in approximately six weeks. If there is a detached tear, this can be repaired arthroscopically with good success. If there is a detached tear that extends into the biceps, to repair this has a poor result and is most commonly treated by detaching the biceps and reattaching it on to the humerus with excellent success. The recovery from any reattachment of the biceps and/or labrum typically involves wearing a sling for six weeks and no overhead activity for 12 weeks.
Call on the Specialists
At Advanced Orthopaedic Specialists, we have seen tens of thousands of shoulder patients and subsequently thousands of patients with superior labral injuries. The majority of these are treated nonoperatively; however, if it does come to an operative treatment, we have experienced excellent success.
If you have any further questions about superior labral injuries, please contact us. We’re here to help!