Superior Labrum Anterior to Posterior tears, more commonly referred to as “SLAP” tears of the shoulder, are injuries affecting the superior glenoid labrum within the glenohumeral or shoulder joint and are due to anterior to posterior detachment of the superior labrum.
The shoulder joint is formed by the articulation between the humeral head and the shallow glenoid of the scapula, or shoulder blade. The glenoid labrum is a fibrocartilaginous ring of tissue that forms a peripheral lining of the bony glenoid socket of the shoulder. It functions to increases the overall surface area of the shallow glenoid, deepen the shoulder “socket”, and stabilize the humeral head, making it more difficult to dislocate the humeral head. Think of the labrum as a soft tissue “bumper” lining the glenoid rim. When the humeral head tries to dislocate, the labrum functions to keep the humeral head centered on the glenoid and prevent it from dislocating. Without the labrum, the shoulder joint would be intrinsically unstable and very easy to dislocate (See: Bankart tears of the labrum). The labrum derives its blood supply from the suprascapular, circumflex scapular, and posterior humeral circumflex arteries of the shoulder. However, the anterior, anterosuperior, and superior aspects of the labrum tend to have decreased vascularity (this is important as it relates to the intrinsic ability to heal SLAP tears. Poor blood supply is a poor prognosticator for the natural history of SLAP tears ie. They don’t usually heal on their own!). Furthermore, the superior labrum is particularly important because this is where the long head of the biceps tendon attaches to the glenoid rim. The long head of the biceps tendon functions to depress the humeral head and serves as an adjunct anterior stabilizer of the shoulder. With a SLAP tear, any traction on the biceps tendon will cause pain in the shoulder.
The labrum acts to enhance the relatively shallow, concave glenoid and increase the effective diameter of the glenoid, improving joint stability. Remember, however, that a SLAP tear is NOT a problem of shoulder instability. In other words, you are not at increased risk of dislocating your shoulder with a SLAP tear.
The most common mechanisms for SLAP tears include forceful traction loads to the arm, direct compression loads, and repetitive overhead activities (ex. throwing, pitching, or serving). A direct traction injury to the biceps tendon can also cause a SLAP tear. However, it is important to note that up to one third of patients with SLAP lesions have no preceding history of trauma.
A conservative, nonoperative approach to treating SLAP tears is usually unsuccessful. Furthermore, simple debridement of unstable SLAP tears (type II and IV) is generally not recommended due to poor post-operative results.
Patient History And Physical Examination
Forceful traction and compression of the shoulder are the two primary mechanisms of injury resulting in a SLAP tear. Remember, however, that approximately one third of patients presenting with a SLAP tear report no history of shoulder trauma. This injury should be considered in a patient that reports persistent shoulder pain that is associated with mechanical symptoms such as catching or locking. The symptoms are usually exacerbated by overhead exercises or activities (ex. throwing a ball or extending the hand above the head). Some special tests a physician may perform to help diagnose a SLAP tear include Speed and Yergason’s Tests, O’Brien’s Test, and the Load-Compression Test. However, there is no single test that can reliably predict a SLAP tear. Rather, the clinician should use a combination of the patient’s history, physical examination findings, and a high clinical index of suspicion given the patient’s presentation, along with advanced imaging, to make the diagnosis.
Imaging And Diagnostic Studies
Although arthroscopy is the most accurate way to diagnose a SLAP tear, magnetic resonance imaging (MRI) can be used in conjunction with contrast arthrography dye (gadolinium) to examine the superior glenoid labrum. And MRI combined with intra-articular contrast is called an MR-Arthrogram and is generally considered the gold standard (aside from arthroscopy) to diagnosing a SLAP tear.
- Glenohumeral Instability
- Rotator Cuff Pathology
- Acromioclavicular (AC) Joint Pathology
- Intra-articular biceps tendinopathy
- Bankart labral tear
A common nonoperative and conservative treatment approach to SLAP tears is physical therapy. Although physical therapy can improve strength and range of motion (ROM) by focusing on the rotator cuff and scapular stabilizers, many patients continue to experience the symptoms of a SLAP tear. An alternative option is an intra-articular corticosteroid injection, which tends to be a therapeutic treatment to help alleviate the symptoms for a period of time.
Surgical treatment of SLAP tears should be considered for patients who have persistent symptoms despite an appropriate course of conservative management. A failure of physical therapy along with persistent shoulder symptoms, in combination with a positive physical examination and advanced diagnostic imaging, should propogate the discussion of surgical intervention. SLAP tears can be managed by one of three surgical strategies: 1) SLAP repair; 2) Biceps tenotomy; or 3) Biceps tenodesis.
For younger, active patients with no previous history of shoulder surgery, an arthroscopic SLAP repair is usually the surgery of choice. Here, a combination of suture anchors are used to re-attach the torn superior labrum back onto the superior glenoid rim. The primary goal of a SLAP repair is to stabilize the biceps anchor and address any co-existing pathology. A biceps tenodesis procedure should be considered for severely degenerative or intractible cases.
Here is an example of a SLAP repair by Dr. Dold.
0-4 Weeks: Patient will need to wear a sling at all times with the exception of hygiene and all active ROM exercises except external rotation in abduction can be performed after 2 weeks.
4 Weeks: Discontinue sling and begin passive ROM exercises with emphasis on posterior capsular stretching.
6 Weeks: External rotation in abduction is allowed and the patient may now begin strengthening exercises.
3 Months: Being return to sports. No throwing until 4 months post-op.
Dr. Dold’s customized rehabilitation protocol will be given to you at the time of surgery. Physical therapy generally starts within a week of surgery and continues for 4-5 months following the surgery.
- Infection (Rare)
- Brachial Plexus Neuropathy
- Persistent Pain or a recurrent SLAP tear (usually requires repeat surgery for biceps tenodesis or occasionally a revision repair).
Dr. Dold’s most recent SLAP book chapter: Type 2 SLAP tear in a 22 year old male with associated Buford complex treated with SLAP repair with care to avoid overconstraining anteriorly. In The Biceps and Superior Labrum Complex pp 173-186.
Results of arthroscopic repair of type II superior labral anterior posterior lesions in overhead athletes: assessment of return to preinjury playing level and satisfaction. AJSM 2011.
Clinical and radiological outcomes of type 2 superior labral anterior posterior repairs in elite overhead athletes. AJSM 2013.
Return to play after Type II superior labral anterior-posterior lesion repairs in athletes: a systematic review. CORR 2012.
The outcome of type II SLAP repair: a systematic review. Arthroscopy, 2010.
Diagnosis and management of superior labral anterior posterior tears in throwing athletes. AJSM 2013.
Nonoperative treatment of superior labrum anterior posterior tears: improvements in pain, function, and quality of life. AJSM 2010.
Isolated type II superior labral anterior posterior lesions: age-related outcome of arthroscopic fixation. AJSM 2009.
Superior labral tears of the shoulder: pathogenesis, evaluation, and treatment. JAAOS 2009.
SLAP lesions: anatomy, clinical presentation, MR imaging diagnosis and characterization. Eur J Radiol 2008.