Imagine you love rock climbing. You love rock climbing so much that you have planned to move to be closer to good climbing. As you prepare to move, you lift a heavy object and feel a pop followed by searing pain in your shoulder. Imaging shows an injury to the tissue that surrounds the joint but symptoms have mostly subsided. You have done your research, and although you don’t want surgery, you’ll do it if it means you can climb again. Your physician wants to try conservative management and sends you to physical therapy. A good (but lengthy) course of physical therapy, along with a regular shoulder maintenance program should get you to the face of the mountain in no time.
SLAP tears (superior labrum anterior and posterior) in the shoulder can be acute, chronic, or degenerative. These tears often occur along with other shoulder injuries such as posterior labral tears, Bankart lesions, or rotator cuff injuries. This is a relatively common injury with a reported prevalence between 6% and 12% in the general population.
Shoulder joint anatomy
The shoulder girdle consists of four joints working synergistically to create the most flexible joint in the body. The glenohumeral, acromioclavicular, sternoclavicular, and scapulothoracic joints work as a team to produce motion. These joints are formed by the humerus, scapula, clavicle, and ribs and allow flexion/extension, abduction/adduction, and internal rotation/external rotation.
The glenohumeral joint is typically identified as the “shoulder” joint. It is a ball-and-socket joint where the head of the humerus meets the glenoid fossa of the scapula. The shape of the joint is analogous to a golf ball on a tee because the shallow glenoid offers little to no restriction of motion. The face of the glenoid is described using the numbers on a clock to reference where particular structures lie.
What the glenohumeral joint lacks in bony stability, it gains from muscles, ligaments, and cartilage. The glenoid labrum is a fibrocartilaginous structure that deepens the fossa by creating a flexible cup for the humeral head to rest in. The labrum is larger at the top and restricts front to back motion of the humeral head. The most superior part of the labrum is attached to the long head of the biceps tendon at the 12:00 position.
The major muscular stabilizers in the shoulder are the supraspinatus, infraspinatus, teres minor, and subscapularis muscles, collectively known as the rotator cuff. The main job of the rotator cuff is internal and external rotation (think throwing motion) but arguably, their more important job is keeping the humeral head in place- and out of the way during movement. The rotator cuff acts like the strings of a marionette to move the humeral head in and out of positions to create smooth, coordinated, unobstructed motion. If not for the action of the cuff, the humeral head would butt up against the acromion process with every arm raise.
(This video demonstrates the location of the clock face orientation of the glenoid labrum at 1:50.)
The nerve supply to the shoulder originates in the brachial plexus. The suprascapular nerve passes below the suprascapular ligament along with the suprascapular vessels. The suprascapular nerve has several branches that supply supraspinatus and surrounding muscles. The suprascapular nerve then travels through the spinoglenoid notch where it branches off to innervate infraspinatus.
Causes of a SLAP tear
Historically, SLAP tears were thought to be unique to overhead athletes. Over the past 20 years, this diagnosis has become more common in the general population as we have discovered labral pathology is quite common. Acute tears can happen during an errant baseball throw or a fall on an outstretched arm (FOOSH injury). Conversely, chronic or degenerative tears can occur as part of the wear-and-tear process associated with normal aging or from a job or sport that requires repetitive motion.
Injuries to the labrum are often associated with overhead athletes. The deceleration phase in baseball, tennis, volleyball, and other sports is often the cause of injury. In this position, the shoulder is abducted and maximally externally rotated which stresses the connection of the biceps tendon to the labrum; this results in a “peel-back” mechanism of injury. Sports and occupations that involve repetitive motion at the shoulder, such as swimming or electrician work, may also lead to SLAP lesions. SLAP tears happen in non-athletes as well; dislocation/subluxation of the humeral head, internal impingement, heavy lifting, and posterior capsule tightness may also lead to SLAP tears.
The clinical presentation of SLAP tears is variable. There is no cluster of historical or physical findings that are suggestive of labrum injury, but it seems they are more prevalent in the dominant shoulder of men in their late 30s. A robust study in the Journal of Shoulder and Elbow Surgery looked at arthroscopic shoulder cases from 1985 to 1993. They reported pain was the most prevalent SLAP tear symptom followed by catching or grinding. More than 40% of SLAP lesions were associated with rotator cuff tears. One-third of the cases were isolated labral injuries.
Depending on the mechanism of injury, the patient may be unable to recall when the pain started. In the case of a fall or sports injury, they may easily relay the history of the injury, but if the tear is degenerative, the onset of symptoms may have been gradual. Patients with SLAP lesions often have difficulty sleeping, particularly if their preferred sleeping position involves having their injured arm overhead. The presence of mechanical symptoms will make the savvy clinician suspicious of a SLAP tear.
Over time, the labrum can get worn down by normal daily activities leading to tearing or fraying. Erickson and colleagues’ systematic review in The American Journal of Sports Medicine” found that when compared to younger patients, those over 40 who had surgical repair of SLAP tears experienced more pain and stiffness post-repair. The group noted that patients may do better with biceps tenotomy or tenodesis, which suggests at least some portion of the pre-operative symptoms may originate in structures other than the labrum. Other research groups have identified the long head of the biceps tendon as a potential source of anterior shoulder pain as well.
The presence of a SLAP tear on imaging increases with age but this does not mean the labrum is the source of pain or symptoms. A 2016 study in the Orthopaedic Journal of Sports Medicine indicated the prevalence of asymptomatic SLAP lesions in patients aged 45 to 60 years ranged from 55% to 72%. These rates are consistent with findings for asymptomatic structural abnormalities of the hip, knee, and spine. It is critical that the clinical presentation and imaging findings are correlated when determining which tissue is implicated.
Overuse or repetitive movements
The peel-back mechanism is a type of degenerative labrum tear that is associated with overuse or repetitive motions. These SLAP tears, often found in overhead athletes or laborers (electricians, landscapers, painters, etc.), may present with an insidious onset. Commonly, these patients report deep, progressive shoulder pain when in the overhead position. In this position, the biceps tendon is being stressed anteriorly while the humeral head glides posteriorly which creates the “peeling” of the labrum.
Prognosis of a SLAP tear
Both surgical and non-surgical SLAP tear cases have a good prognosis when careful attention is paid to who undergoes labrum surgery. Research shows those with isolated unstable Type II SLAP lesions can anticipate good to excellent results and a successful return to their prior level of activity. These favorable outcomes held true regardless of age although older patients needed longer to achieve their goal. Some patients had small range of motion deficits, but final outcomes did not seem to be affected. Among athletes undergoing Type II SLAP repair, nearly 75% returned to their pre-injury level of competition and of those who reported a discrete traumatic tear event, 92% made a complete return.
There is little evidence beyond case reports regarding the effectiveness of conservative management of SLAP tears but there is reason to be optimistic. Significant decrease in pain, improved quality of life, and similar return to activity as seen in surgical patients have all been reported. Overhead athletes and those who fail conservative management due to continued pain and functional limitations should consider surgical intervention.
Diagnosis of a SLAP tear
Patients with SLAP tears often report diffuse pain and mechanical symptoms such as clicking or popping when moving in and out of the overhead position. Depending on the extent of the tear, they may report instability or feelings of their humeral head subluxating. Though patients with SLAP tears may have pain at night if they sleep with an arm overhead, they do not generally report the pain when lying on the involved side that is typical of patients with rotator cuff tears.
During the physical exam, most patients with SLAP lesions will report pain with passive range of motion when the shoulder is abducted 90 degrees and externally rotated at 90 degrees. Those with isolated SLAP tears may be strong during resisted testing; if rotator cuff pathology is present, the patient may have associated weakness in these muscles. The clinician should rule out instability prior to using special tests to determine the presence or absence of a labral tear to avoid exacerbating symptoms or creating additional injury.
Several shoulder labral tear tests can determine the presence of a tear including: O’Brien’s active compression test, the grind test, Speed’s test, the clunk test, the anterior slide test, the biceps load I and II tests, and the pain provocation test. Although these tests are helpful in determining the presence of labral pathology, their findings can be inconsistent and none is particularly good at identifying labral tears on its own; additionally, these tests may not be accurately reproduced among examiners.
While there is some controversy about its reproducibility, in more than 20 years of working with overhead athletes, I have found O’Brien’s active compression test to be most indicative of a torn labrum. As with any musculoskeletal injury, it is critical that the patient’s symptoms and clinical presentation are correlated when making this diagnosis.
Although ten types of SLAP tears have been identified, there is some controversy over whether these should all be considered SLAP versus extensive labral abnormalities in their own right. There is no clear evidence that all ten types of injury can be identified on imaging. Most surgeons will be familiar with types I to IV.
It is posited that certain classifications are associated with particular mechanisms of injury. Age-related degenerative tears are generally type I lesions. Repetitive overhead motions are often type I or II tears. Types III, IV, and V are associated with falls on an outstretched arm. Type V and VII may be found in individuals with glenohumeral instability following acute injury. Bankart lesions typically occur during anterior-inferior humeral dislocations while middle glenohumeral ligament is most often implicated in straight anterior dislocations.
Type I SLAP tears involve fraying with no frank tear at the superior aspect of the labrum and an intact biceps tendon.
Type II SLAP tears are the most common and describe labral fraying with involvement of the biceps tendon. The three subcategories of type II lesions are: type IIA is an anterosuperior labral tear, type IIB is a posterosuperior labral tear, and type IIC is a superior tear that extends anteriorly and posteriorly.
Type III lesions are bucket-handle tears of the superior labrum where the central piece of the tear is displaced into the glenohumeral joint (similar to a bucket-handle meniscus tear).
Type IV tears are similar to type III but extend to the biceps tendon.
There are also levels V to X tears, but these are the rarest of the rare cases.
Controversy of SLAP tear
The ideal treatment for a symptomatic labral tear in patients older than 40 is unclear. Post-operative pain and stiffness has led to questioning if the labrum is the pain-generating tissue in these patients. Research has shown these patients do well with biceps tenodesis or tenotomy which suggests the pain may be coming from the biceps tendon rather than the labrum.
A 2014 systematic review in the American Journal of Sports Medicine noted that these alternative procedures have shown favorable outcomes in patients with isolated labrum tears and those having a simultaneous rotator cuff repair procedure. Juli Boyer, who is a physician assistant at the Orthopaedic Speciality Institute in Orange County, Calif., echoed this sentiment. Boyer noted that in her sports medicine based practice, they start worrying about post-operative pain and stiffness in patients as young as 35, and they seem to have more favorable outcomes with biceps tenodesis than traditional labral repairs in patients with non-traumatic labral tears.
Treatment for a SLAP tear
The first line treatment for SLAP tears is typically arthroscopy. Type I lesions often require debridement only. In other types of tears, the primary surgical goal is to reattach the biceps tendon to the glenoid rim and to remove any tissue fragments that may be associated with a type III or IV tear. Indications for surgery include those with large concomitant rotator cuff tears and those with mechanical symptoms such as clicking, popping, or feelings of instability. Generally, type I and III require debridement only while II and IV undergo repair.
It seems that some–maybe even most–patients with age-related degeneration are not appropriate candidates for debridement or repair. The labral fraying seen on imaging is part of the normal aging process and these patients do well with restored range of motion, improved strength, postural education, and activity modification.
“A lot of patients are eager to go the surgical route without even thinking about their potential success with conservative management,” Boyer remarked.
She said that she sees a lot of patients who benefit from physical therapy alone and “encourages every patient to exhaust their conservative management options before considering SLAP tear surgery.”
Corticosteroid injections are not typically successful in patients without an intact labrum. Despite some evidence that conservative management can be successful, there is no current literature supporting the use of injection in these patients.
As with any injury or illness, readers should consult with a physician or qualified medical professional to determine the best personal course of treatment.
SLAP tear and massage therapy
Massage therapists should be well-versed in the biomechanics of the shoulder when working with individuals with SLAP tears. Regardless of which structure is involved, it is critical that they understand how short, tight muscles in the anterior shoulder can alter the function of the scapular stabilizers and postural muscles on the posterior side.
Soft tissue mobilization in the supine position should target the pectorals, specifically pectoralis minor. Pectoralis minor attaches to the coracoid process so tightness will create anterior tipping of the scapular and close down the subacromial space. Focused work on the internal rotators may also be necessary to decrease the “rounded” shoulder that can result from the bracing position used with a painful shoulder (arm held against the body with elbow flexion- similar to where the arm would rest in a protective sling). The region of subclavius should also be addressed. Subclavius is responsible for stabilizing the clavicle while the shoulder moves which helps maintain the subacromial space.
The scapular stabilizers and postural muscles may be addressed in prone or side lying. These muscles may become short and tight over time as the individuals with a SLAP tear avoids the pain and symptoms caused by the overhead position. Appropriate scapular motion is an integral component of a healthy shoulder and as such, the massage therapist should work to ensure the individual has the muscle length to create smooth, coordinated upward and downward rotation of the scapula.
The external rotators are often tight through the posterolateral aspect of the shoulder near the musculotendinous junction. Rotator cuff massage to ensure full internal rotation range of motion can not be underscored.
Individuals with labral pathology may benefit from self-mobilization techniques to support the bodywork they are receiving. These individuals can use a tennis or lacrosse ball to address the pectorals, scapular stabilizers, internal rotators (specifically latissimus dorsi), and external rotators. A foam roll may be more comfortable because of the broad contact point when addressing soft tissues. It may be necessary to educate these patients about how to perform this work using the wall rather than the floor if they have limited use of their affected shoulder.
Superior labral tears aren’t just athletic injuries anymore and they don’t all come with trips to the operating room. Normal aging can cause chronic or degenerative tears that can be symptomatic or asymptomatic in active and sedentary individuals.
As of this writing, it’s too early to close the chapter on the rock climber but it’s clear that that physical therapy was the right place to start. In the absence of significant pain and mechanical symptoms, conservative management may be the most appropriate first step in the management of SLAP tears. Those who fail conservative management would be well-served to discuss the option of biceps tenodesis or tenotomy versus SLAP repair to decrease the risk of post-surgical complications and improve outcomes.