Superior Labral Lesions Treatment & Management


Background

Superior labral (labrum) lesions can cause painful mechanical symptoms and difficulty with overhead activities whether they be athletic or those of daily living. [1Superior labrum tears were first described by Andrews et al. [2In a study that reviewed their experience in 73 throwing athletes, the authors identified tears of the labrum involving the anterosuperior aspect near the origin of the biceps tendon. They attributed this lesion to the biceps tendon being pulled off the labrum as a result of force generated during the throwing motion.

Snyder et al coined the term SLAP (superior labrum, anterior and posterior) lesion to describe a more extensive injury. [3A SLAP lesion, as described by Snyder, involves a tear of the superior labrum, which starts posteriorly and extends anteriorly to include the anchor of the biceps tendon to the superior labrum. The injuries were subdivided into four types (I-IV). Much as in Andrews' findings, a subset of patients who reported a traction injury were identified. However, the majority of patients related a history of a compressive injury to the shoulder secondary to a fall on an outstretched arm in a flexed and abducted position.

SLAP lesions, as opposed to occult anterior instability, are likely the underlying cause of the so-called dead arm syndrome in throwing athletes. Regardless of whether injuries to the superior labrum–biceps complex are secondary to a throwing or nonthrowing etiology, they can be a source of considerable disability for the patient.

These injuries are difficult to diagnose on physical examination because the findings are often nonspecific and demonstrate considerable overlap with those of other etiologies of shoulder pain. Similarly, both nonenhanced magnetic resonance imaging (MRI) and magnetic resonance arthrography have variable accuracy in determining if a SLAP lesion is present. At times, the only definitive way to diagnose a SLAP lesion is with a diagnostic arthroscopy. [4]

Even so, a thorough understanding of the normal anatomy and biomechanics of the superior labral–biceps complex, as well as commonly observed normal anatomic variants, is mandatory to ensure appropriate surgical stabilization and to avoid unnecessary repair of the superior labrum. [5]

Initial operative treatment of superior labral lesions consisted of debridement only. This therapy is appropriate for type I and type III lesions, as well as for some type IV lesions, in which the biceps anchor is intact. However, in type II and in type IV lesions in which the biceps anchor is unstable, debridement alone yields poor results.

Early attempts at arthroscopic fixation used a metal staple. This technique was discontinued because of concerns for chondral injury as well as the need for a second surgery for staple removal. For similar reasons, techniques involving a metal screw are no longer used. A transglenoid technique similar in concept to a transglenoid technique for a Bankart repair has been described; however, this is technically difficult and has fallen out of favor. Good results were initially reported with use of a bioabsorbable tack. [6However, complications, including implant breakage with resultant particulate debris and a foreign body reaction, have been reported.

The use of suture anchors loaded with nonabsorbable suture is the preferred method of fixation. [7]

Anatomy

The glenoid labrum is a triangular fibrocartilaginous structure that serves to deepen the glenoid. Whereas tears of the anteroinferior labrum have long been known to be associated with significant shoulder pathology, it is really only since the advent of shoulder arthroscopy that injuries of the superior labrum have been appreciated as a potential pathologic lesion.

The superior labrum often has a more meniscoid attachment to the glenoid rim compared with the remainder of the labrum and therefore may be more susceptible to both degenerative and traumatic lesions. It also serves as part of the origin of the long head of the biceps. Injuries to the superior labral–biceps complex can compromise the biceps anchor. Furthermore, the repetitive tensile force exerted by the biceps on the superior labrum likely contributes to poor healing of superior labral tears. [8 (See the image below.)

Superior labrum anterior and posterior (SLAP) lesiSuperior labrum anterior and posterior (SLAP) lesion types.

Snyder classified superior labral tears into four types as follows [3:

  • Type I - Significant fraying of the labrum, with the biceps anchor remaining intact
  • Type II - A tear of the superior labrum that results in instability of the biceps anchor; as in type I tears, significant fraying of the labrum occurs; in addition, the superior labrum and associated biceps anchor are stripped away from the superior glenoid
  • Type III - A bucket-handle tear of the superior labrum, with the central portion of the superior labrum torn and usually displaced into the joint; the peripheral attachment of the labrum is intact, and the biceps anchor is usually stable
  • Type IV - A bucket-handle tear of the superior labrum, as in type III; however, the tear also propagates to a variable degree into the biceps tendon

Modifications have been made to the original classification.

Morgan and Burkhart subdivided the type II lesions into three subtypes: anterior type II, posterior type II, and combined type II (referring to the tear involving the labrum both anterior and posterior to the biceps anchor). [9]

Maffet et al expanded the original classification to include types V, VI, and VII, defined as follows [10:

  • Type V - A Bankart lesion that extends superiorly to include the superior labrum and biceps anchor
  • Type VI - A flap tear of either the anterior or the posterior superior labrum with an associated type II tear
  • Type VII - A tear of the superior labrum that includes the middle glenohumeral ligament

Type II lesions are by far the most common and are also the source of the greatest diagnostic difficulty.

To accurately classify superior labral (labrum) lesions, one must be aware of normal anatomy, including the many normal variants that are observed. The biceps tendon origin is divided roughly in half between the supraglenoid tubercle and the superior labrum. Vangsness et al demonstrated that the labral insertion is entirely or mostly into the posterior labrum about 55% of the time. [11Only a small percentage (~8%) have a predominant anterior insertion. The remainder have equal insertions to the anterior and the posterior labrum.

In an anatomic study, Cooper et al noted that the superior portion of the labrum had a distinctly different morphology from the inferior labrum. [12The superior and anterosuperior portions were found to be loosely attached to the glenoid rim through thin connective tissue that easily stretched. This is similar to what is seen in the meniscus of the knee. In contrast, the inferior labrum had a firm attachment through thick inelastic fibers and appeared as a firm immobile extension of the glenoid articular cartilage. The 12-o'clock position was the only location on the glenoid rim where the hyaline articular cartilage extended over the rim of the glenoid.

The biceps tendon inserts into the supraglenoid tubercle, which is 5 mm medial to the glenoid rim. This, along with the often meniscoid attachment of the superior labrum, results in a sublabral recess.

This should not be mistaken for a type II SLAP lesion. As reported by DePalma, a sublabral recess may be present in as many as 50% of individuals older than 20 years. [13This incidence increases with patient age. In DePalma's study, more than 95% of the specimens obtained from patients in the seventh and eighth decades of life were found to have a sublabral recess.

The middle glenohumeral ligament can sometimes insert directly into the superior labrum as a large thick cordlike structure (ie, the so-called Buford complex). In these cases, the anterosuperior labrum is absent. The Buford complex is not pathologic and should not be stabilized, because to do so would markedly restrict external rotation. A sublabral foramen can be observed where the anterosuperior labrum, from approximately the 1- to 3-o'clock position in a right shoulder, is loosely attached or not attached at all to the glenoid rim. Again, this is not pathologic and should not be stabilized; to do so would result in a significant loss of external rotation.

Histologically, the superior labrum is composed of fibrocartilage, consisting of type II cartilage in a relatively acellular matrix with occasional interspersed elastin fibrils. This is in contrast to the hyaline cartilage of the glenoid and the dense fibrous glenohumeral capsule. Branches of the suprascapular, circumflex scapular, and posterior humeral circumflex supply the labrum. Periosteal and capsular vessels supply the labrum throughout its periphery. No vessels enter the labrum from the underlying bone. In general, the superior and anterosuperior labrum have less vascularity than other portions of the labrum.

Pathophysiology

On a biomechanical level, incompetence of the superior labrum and biceps anchor has been shown to have a deleterious effect on anterior glenohumeral stability. In a cadaver study, Rodosky et al compared anterior glenohumeral stability in specimens with an intact superior labrum with those with a SLAP lesion. [14They demonstrated that the presence of a SLAP lesion decreased the torsional resistance by 11-19%, in comparison with the intact shoulder, as it was placed in the abducted and externally rotated position. The inferior glenohumeral ligament was subject to significantly increased (>100% greater) strain in the presence of a SLAP lesion.

In another cadaver study, Pagnani et al demonstrated that a SLAP lesion resulted in significant increases in both anterior-posterior and superior-inferior translations. [15At 45° of elevation, a 6-mm increase was noted in anterior translation with the arm in neutral rotation, and a 6.3-mm increase in translation in internal rotation occurred.

Several other studies have examined the strain changes in the superior labrum and biceps anchor with different positions of the throwing motion. Pradhan et al found that a significant increase in strain in the anterior and posterior portions of the superior labrum only occurs when the arm is in maximum external rotation, as is the case in the late cocking phase. [16Furthermore, the strain in the posterior portion of the superior labrum was significantly higher than that in the anterior portion.

Kuhn et al supported these findings with their study of failure patterns of the superior labral–biceps complex. [17They found that failure was significantly more likely in the late cocking position than in the early acceleration position. In the late cocking position, nine of 10 specimens demonstrated failure of the superior labral–biceps complex. In contrast, of the 10 paired specimens that were tested in the early acceleration position, only two had failure of the this complex. The load to failure was significantly less in the late cocking position than in the early acceleration position. Of the five type II SLAP lesions that developed, four were in the late cocking positions.

These studies emphasize the important role the superior labral–biceps complex likely plays in anterior shoulder stability. An unstable SLAP lesion found in the course of a Bankart repair should be stabilized. The important role of the posterior portion of the superior labrum likely reflects the fact that the biceps tendon attachment is usually posterior-dominant, as demonstrated in a study by Vangsness et al. [11In repairing SLAP lesions, particular attention should be given to ensuring that the posterior aspect is well stabilized.

Etiology

In considering the etiology of superior labral (labrum) lesions, it is useful to divide them into the the following two broad categories:

  • Compression injuries - These are usually secondary to a fall on an outstretched arm that is in an abducted and slightly flexed position, which can can result in a compressive load to the superior labrum with a resultant tear; a direct blow to the shoulder has also been found to be a contributing factor for SLAP lesions
  • Traction injuries -  These can be secondary to a sudden pull in an inferior direction, such as occurs when an individual loses hold of a heavy object; an overhead traction force, as when individuals attempt to catch themselves from falling from a height, can also result in a superior labral injury

Clearly, engaging in throwing sports can predispose to the development of a SLAP lesion. The exact mechanism by which the lesion develops is somewhat controversial. In Andrews' original 1985 study, traction force placed on the superior labrum by the biceps tendon in the follow-through phase of the throwing motion was thought to be responsible for creating a SLAP lesion. [2The hypothesis was that the eccentric contraction of the biceps necessary to decelerate the elbow resulted in the biceps tendon detaching portions of the glenoid labrum.

Subsequent studies, however, suggested that the forces generated during the late cocking phase are in fact the predominant factor. The peel-back mechanism described by Burkhart and Morgan [18and the shear forces generated by a tight posteroinferior capsule are thought to be major contributing factors to developing type II SLAP lesions or variants thereof.

The presence of a peel-back sign can be demonstrated arthroscopically. The arm is placed into 70-90° of abduction and then progressively rotated externally. In this position, the biceps vector is now more posteriorly and vertically oriented. To accommodate this, the base of the biceps twists. A torsional load is transmitted to the superior labrum, and if the posterosuperior labrum and biceps anchor are incompetent, medial displacement of the superior labral–biceps complex occurs. If more than 5 mm of the posterosuperior glenoid is uncovered or the biceps root at the level of the supraglenoid tubercle is uncovered, a posterior type II SLAP lesion is present.

As already noted, posterior capsule tightness is thought to play an important role in the development of SLAP lesions. Almost all high-demand throwers develop a posterior capsular contracture with limitation of internal rotation. This tight posteroinferior capsule is thought to result in obligatory superior translation of the humeral head when the arm is in abduction and external rotation and, as a result, exposes the superior labrum to large shear forces. This increased shear force is most pronounced at the same time the peel-back forces are at their maximum, increasing the likelihood of a SLAP lesion developing.

Epidemiology

Superior labral (labrum) lesions are unusual. The reported prevalence in patients undergoing shoulder arthroscopy has ranged from 3.9% to 6%. In the largest series reported, SLAP lesions represented 6% of 2375 patients who underwent shoulder arthroscopy. The average age was noted to be 38 years, and 91% of the patients were male. The reported incidence of types I-IV is variable, with type II lesions being the most common. Type I lesions have been reported to account for 9.5-21% of all cases; type II, 41-55%; type III, 6-33%; and type IV, 3-15%.

Prognosis

Initial reports suggested good results with arthroscopic superior labral repairs with a high success both in nonthrowing and throwing athletes, as well as a high rate of overhead athletes returning to their preinjury level of activity. [1920Morgan et al reported on their results in 102 patients, [9with 83% having excellent results and 14% having good results. All pitchers returned to pitching, 84% of them at preinjury levels.

Pagnani et al reported that 12 of 13 overhead athletes were able to return to full preinjury level of activity after an arthroscopic superior labral tear. [21Field and Savoie, [22as well as Burkhart et al, [23reported similar findings. In Field and Savoie's study, all of the athletes were able to return to sports activities without limitation.

However, it has become evident that overhead throwing athletes have poorer outcomes after superior labral repair than nonthrowers do and that this is especially true if there is an associated rotator cuff tear, either partial or full thickness. [24101816Furthermore within the overhead athlete group, baseball players have a lower rate of returning to preinjury level of activity. [1314]

Kim et al evaluated their results in 34 individuals who underwent arthroscopic suture anchor repair of an isolated SLAP lesion tear. [24Approximately 94% had a satisfactory result as determined by using the University of California Los Angeles (UCLA) shoulder score. Thirty-one (91%) of the patients regained their preinjury level of function. However, outcomes were poorer in overhead athletes than in those not participating in overhead athletic activities.

In a prospective study, Brockmeier et al reviewed their outcomes after arthroscopic repair of a type II SLAP tear in 47 patients and reported that 87% had a good or excellent result. [25However, only 74% of the patients were able to resume their preinjury level of athletics. Patients with a discrete traumatic event had a greater likelihood of resuming preinjury level of activity. In a subgroup of 12 athletes who had discreet traumatic event, 11 (92%) were able to resume preinjury level of activity.

Neuman et al retrospectively reviewed their results of type II superior labral repair in 30 overhead athletes. [26Overall, 93% had good-to-excellent results and 84% returned to preinjury level of play. However, with subgroup analysis, baseball players only had an 80% return to preinjury level of play compared with 94% for other overhead athletes.



History

Patients with superior labral (labrum) lesions often present describing a poorly defined pain that is posterior in location. They can also describe a painful popping and clicking similar to mechanical symptoms associated with a meniscal tear.

Nonthrowing individuals may report a history of a fall either on an outstretched arm or in which a direct impact on the shoulder occurred. A history of a sudden deceleration injury, such as occurs when one loses control of a heavy object that is being carried, may be present.

In a throwing athlete, a discrete injury with no prodromal period may be reported. In contrast, the athlete may not recall a specific injury and merely report a prodromal phase consisting of some mild posterior pain with a sense of posterior tightness.

Physical Examination

The patient's range of motion should be carefully assessed, especially in the throwing athlete. [27Throwers often develop a loss of internal rotation in abduction. This loss of internal rotation with tightness of the posteroinferior capsule is thought to be a risk factor for the development of a SLAP (superior labrum, anterior and posterior) lesion. One should be especially cognizant of this entity in an individual who presents with loss of internal rotation at the expense of a 180° arc of motion with the arm abducted 90°. Burkhart and Morgan postulated that this finding defines a shoulder at risk of developing a type II SLAP lesion and the dead arm syndrome. [23]

An acute SLAP lesion, especially a posterior type II lesion, can manifest as posterior shoulder pain in abduction and external rotation, decreased throwing velocity, and easy fatigability. This symptom complex has been labeled the dead arm syndrome. Multiple physical examination tests for a SLAP lesion have been described; however, correlation with arthroscopic findings has been poor. Furthermore follow-up studies by independent investigators have been unable to reproduce the high sensitivities, specificities, and positive-predictive values reported by the authors who originally described the tests. [2829]

In Snyder's initial report describing SLAP lesions, he used the biceps tension (Speed) test and the compression rotation test. [3The Speed sign is positive when pain is elicited with resisted flexion of the fully supinated arm with the elbow extended and the arm flexed to 90°. The compression-rotation sign is performed with the patient supine, the shoulder elevated to 90°, and the elbow flexed to 90°. An axial load is then applied to the humerus to compress the glenohumeral joint, and the arm is rotated. Pain as well as mechanical symptoms elicited during this test are considered positive test results. Multiple other tests have been described. [28]

The O'Brien sign, or the active-compression test, is elicited by first placing the arm in 90° of forward flexion and 10° of adduction. [303132The arm is then fully internally rotated into the thumbs-down position. The patient is then asked to resist downward pressure to the arm that is applied by the examiner. Differentiate deep-seated shoulder pain from that localized to the anterosuperior aspect of the shoulder because the latter is associated with acromioclavicular (AC) joint pathology.

The test is then conducted again, but with the arm in full supination; the pain should be decreased in this position as compared with the initial position for the test result to be considered positive. A positive Speed test as well as a positive O'Brien sign is thought to be consistent with an anterior type II SLAP tear.

Kibler described the anterior slide test to help diagnose anterior SLAP lesions. [33The patient is instructed to place both hands on the hips. The examiner stabilizes the scapula with one hand over the acromion. The other hand is used to axially load the humerus in an anterior and superior direction. Pain with this motion is considered to be positive for an anterior-based SLAP lesion.

Kim et al described the biceps tension test II. [34The shoulder is placed in 120° of abduction and full external rotation, and the elbow is flexed to 90° and fully supinated. The patient is then instructed to flex against resistance. Pain with this is consistent with a SLAP lesion.

Kim et al also described the biceps tension test I to help determine the presence of a SLAP lesion in the patient with unidirectional anterior instability. An anterior apprehension test is first performed, which in this subgroup of patients is positive for instability. Resisted elbow flexion with the arm fully supinated should decrease the sensation of instability if the superior labral–biceps complex is intact. In the presence of a SLAP lesion, no alleviation of the instability sensation occurs.

The Jobe relocation test has been used to help diagnose posterior type II SLAP lesions. [35The patient is placed in the supine position. The arm is placed in 90° of abduction and maximum external rotation. Pain in this position that is alleviated with a posteriorly directed force to the proximal humerus is consistent with a posterior type II lesion. Differentiate the sensation of pain in this test as opposed to that of instability found in an anteriorly unstable shoulder. Patients with type III and type IV lesions are more likely to report mechanical symptoms, although eliciting these on physical examination is often difficult.

Despite the multitude of described tests for a SLAP lesion, none has proved reliable to date. Follow-up independent studies have demonstrated poor sensitivities, specificities, and positive predictive values. [3637 A study by Somerville et al suggested that although a combination of these tests may be slightly superior to any single test for diagnostic purposes, clinicians should rely more on diagnostic imaging. [38]

Check for rotator cuff impingement signs on examination. [39The prevalence of rotator cuff tears, either partial- or full-thickness, in patients with SLAP lesions has been noted to be in the 30-40% range.


Imaging Studies

On plain radiography of the shoulder, an anteroposterior (AP) view of the shoulder in internal and external rotation, outlet, and axillary views should be obtained. [40Findings are usually normal. Occasionally, a SLAP (superior labrum, anterior and posterior) fracture, which represents a superior humeral head compression fracture, can be observed. Plain radiographs should be carefully reviewed for other potential pathology, such as an os acromiale, an anterior acromial spur, or a degenerative acromioclavicular joint.

Nonenhanced magnetic resonance imaging (MRI) has proved to be unreliable in determining the presence of SLAP tears. [4142It is useful to evaluate potential concomitant pathology, such as partial- or full-thickness rotator cuff tears. It is also valuable in detecting the presence of a paralabral cyst. Ganglion cysts encroaching on the spinoglenoid notch are associated with superior, usually posterior, labral tears.

The use of contrast medium, as in magnetic resonance arthrography, offers improved visualization of intra-articular structures and is thought to improve the ability to accurately detect SLAP tears; however, reported results continue to be highly variable. [434445 A study by Lee et al found that in magnetic resonance arthrography of the shoulder, T1 high-resolution isotropic volume excitation (THRIVE) sequences yielded better results than two-dimensional three-plane proton-density fat-suppressed (2D-PD-FS) sequences for diagnosing SLAP lesions. [46]

Two useful signs on MRI are those of increased signal intensity in the posterior third of the superior labrum and a laterally curved intensity. The sublabral recess does not usually extend to the posterior third of the superior labrum, and therefore, high signal intensity between the labrum and the glenoid in this region is considered to be consistent with a superior labral tear. Another MRI finding considered to be highly suggestive of a superior labral tear is laterally curved signal intensity. On the contrary, a normal sublabral recess results in a medially curved area of signal intensity.

The findings of a retrospective review study indicated that whereas multidetector computed tomography (CT) arthrography showed limitations in the overall percentage of correct classification, it showed high accuracy and interobserver reliability in the diagnosis of SLAP lesions.



Approach Considerations

Surgical treatment of superior labral (labrum) lesions is indicated in patients who have persistent symptoms despite 3 months of nonoperative treatment. These patients should have the following:

  • Persistent posterior shoulder pain, with or without mechanical symptoms
  • Findings on physical examination consistent with a SLAP (superior labrum, anterior and posterior) lesion
  • Ideally, have supportive findings on magnetic resonance imaging (MRI)

It should be noted, however, that physical findings, as well as MRI findings, are often equivocal. If a high clinical suspicion exists, with the patient continuing to be symptomatic after an appropriate amount of conservative treatment, then strong consideration should be given to diagnostic arthroscopy.

In 2018, the National Athletic Trainers' Association (NATA) issued a position statement addressing the management of SLAP injuries in overhead athletes (see Guidelines). [48]

Future and controversies

There is a growing body of literature addressing the use of biceps tenodesis and labral debridement for unstable SLAP lesions as an alternative to arthroscopic labral repair. This is thought to be especially pertinent in patients older than 40 years, as well as those with an associated rotator cuff tear, but it has also been investigated in the athletically active population, in view of the high failure rate reported for arthroscopic superior labral repair in multiple studies.

Gottschalk et al reported their results for biceps tenodesis for isolated (no rotator cuff tears) type II or IV SLAP lesions in 26 patients (average age, 46.7 years). [49They reported a significant improvement in ASES and VAS scores, with no significant difference based on SLAP lesion type, patient age, or patient sex. In all, 26 of 29 (89.66%) patients were able to return to their previous level of activity.

In a systematic review of the literature, Erickson et al investigated outcome of superior labral repair in patients older than 40 years. [50They concluded that age greater than 40 years and workers' compensation status are independent risk factors for increased surgical complications and that the cumulative evidence supports labral debridement or biceps tenotomy over labral repair when an associated rotator cuff injury is present in that patient population.

Boileau et al compared arthroscopic repair of a type II superior labral tear with performance of a biceps tenodesis and concluded that the biceps tenodesis group had a higher postoperative Constant score and a significantly higher rate of return to a preoperative level of activity and sports participation. [51 Thirteen (87%) of the 15 patients treated with a biceps tenodesis were able to fully resume sports participation, compared with only two (20%) of the 10 patients treated with SLAP repair.

These findings should be treated with caution, however. The overall number of patients in the study was small, and the demographic characteristics, as well as the activity levels, of the two groups were dissimilar, with the SLAP repair group consisting of 10 males with an average age of 37 years and the tenodesis group consisting of nine females and six males with an average age of 52 years.

In a systematic review and meta-analysis, Hurley et al reviewed the literature to compare the outcomes of biceps tenodesis with those of SLAP repair. [52They found that biceps tenodesis resulted in higher rates of patient satisfaction and return to sports as compared with SLAP repair. They also found functional outcome scores to be similar regardless of technique.

The role of biceps tenodesis in the high-performance throwing athlete remains unclear, with most sports surgeons tending to be reluctant to perform a biceps tenodesis in that patient population because of uncertainty about the procedure's effect on throwing mechanics. 

Chalmers et al used surface electromyography (EMG) and motion analysis to compare alterations in pitching mechanics and motion in three groups—uninjured control subjects, patients treated with SLAP repair, and patients treated with subpectoral biceps tenodesis—and found that whereas both tenodesis and SLAP repair can restore physiologic neuromuscular control, SLAP repair may alter trunk biomechanics. [53 However, in a study of return to sport in major league baseball (MLB) players after biceps tenodesis, Chalmers et al reported an 80% rate of return to sport for position players versus only 17% for pitchers. [54]

Taken together, these studies suggest that whereas biceps tenodesis may not affect pitching biomechanics, it may still have a significant effect on the ability to regain preinjury pitching effectiveness, perhaps secondary to loss of velocity and control. Thus, biceps tenodesis should be undertaken with caution in the throwing athlete, and it may be best reserved for cases where SLAP repair has failed or cases involving frank pathology of the long head of the biceps. 

Medical Therapy

Initial treatment of suspected SLAP lesions should be nonoperative. The emphasis should be on rest, which means an initial period of no throwing in the overhead athlete. A course of nonsteroidal anti-inflammatory medication may be considered.

A physical therapy program consisting of posterior capsular stretching, as well as scapula stabilization and rotator-cuff strengthening, should be initiated. Capsular stretching, especially of the posteroinferior capsule, is important to help regain internal rotation. Stretches should include cross-body adduction stretches and the “sleeper” stretch.

Edwards et al reported on nonoperative management of type II lesions in a retrospective questionnaire-based study and showed that successful nonoperative management resulted in improved pain relief and functional outcomes as compared with pretreatment assessments. [55]

Failure to respond to conservative treatment after 3 months may indicate the need for operative fixation.

Surgical Therapy

Initially, a complete diagnostic arthroscopy is performed. The rotator cuff should be carefully inspected for any partial- or full-thickness tears. The biceps anchor is inspected. Be aware of the potential normal variants (see Overview). Type III and type IV SLAP lesions are fairly obvious arthroscopically. The difficulty can sometimes come in differentiating a type I lesion from a type II lesion, as well as accurately diagnosing type II lesions and variants thereof.

Type I lesions are often associated with a meniscoid superior labrum where the lateral aspect is draped over the rim of the glenoid superiorly and the attachment is more peripheral. This particular morphology is more susceptible to developing degenerative tears, which is the pathology observed in type I lesions. Care must be taken not to assume that this meniscoid labrum represents a displaced type II lesion.

A probe is placed under the superior labrum, and a firm attachment is demonstrated. In inspecting the superior labral attachment, the key factor to evaluate is whether more than 5 mm of superior glenoid is exposed under the labrum. A superior sublabral recess is often observed and is a normal finding. However, if this recess is greater than 5 mm, the biceps anchor is highly likely to be unstable. [5657]

The superior labrum, both anterior and posterior to the biceps root, should be carefully probed. Placing the arm in approximately 70-90° of abduction and then progressively externally rotating the arm can demonstrate the peel-back sign, which is observed with type II posterior lesions, as well as with combined anterior and posterior type II lesions. If the biceps root at the level of the supraglenoid tubercle is uncovered with this maneuver, then the peel-back sign is positive and the superior labrum must be repaired. The peel-back sign is not usually observed with type II anterior SLAP lesions.

A positive drive-through sign where the arthroscope can be easily passed from the superior aspect of the joint to the inferior recess without any manual distraction can be observed with all three variants of type II SLAP lesions. This anterior pseudolaxity is usually resolved with repair of the SLAP lesion, and the drive-through sign is eliminated.

Surgical treatment of a type I lesion consists of debridement. Similarly, in a type III lesion, the bucket-handle tear of the meniscus can be debrided because the biceps anchor is usually intact. The labrum should, however, be carefully probed, and it should be repaired if it has an unstable attachment. In a type II lesion, the biceps anchor is repaired back down to the superior labrum with suture anchors.

In type IV lesions, if less than 30% of the tendon is involved and the biceps anchor is intact, then the involved labrum and tendon can be resected back to a stable rim. If more than 30% tendon involvement is noted in an older patient, a biceps tenodesis is prefered. In the younger, more active individual, suture repair of the tendon, along with suture anchor repair of the labrum, should be considered; however, severe biceps tendon tearing is best treated by tenodesis.

Various techniques have been described to repair the superior labrum arthroscopically. [582459These include the use of metal staples, metal screws, bioabsorbable tacks, and a transglenoid technique. Metal staples and screws require a second surgery for removal and are no longer used. Good results have been reported with the use of bioabsorbable tacks; however, concerns over potential particulate debris and foreign body reaction have led many surgeons to use suture anchors loaded with nonabsorbable suture.

Preparation for surgery

The procedure can be performed with interscalene block and intravenous sedation or with interscalene block and general endotracheal anesthesia. An examination with the patient under anesthesia is conducted to assess for any capsular contracture or instability. The patient may be placed in either the beach-chair or the lateral decubitus position, depending on the surgeon's preference.

Operative details

A standard posterior viewing portal is made. An anteroinferior portal is made just above the subscapularis tendon by means of an outside-in spinal needle localization technique. Similarly, an anterosuperior portal is made. The incision for this portal is just off the anterolateral corner of the acromion and enters the joint through the rotator interval laterally.

Cannulas are placed in both portals, with a large cannula placed in the anterosuperior portal. The area of labral detachment is debrided and any fibrous tissue is removed with a soft-tissue resector. The bone is then lightly decorticated with a burr. (See the images below.)

Area of labral detachment is debrided to expose a Area of labral detachment is debrided to expose a bony bed. The awl for the anchor is introduced either through the anterosuperior portal or can be introduced percutaneously from a posterolateral portal.
Bioabsorbable anchor double-loaded with nonabsorbaBioabsorbable anchor double-loaded with nonabsorbable number 2 suture is then implanted
The suture limbs are passed through the labrum. EiThe suture limbs are passed through the labrum. Either a simple or mattress stitch can be utilized. Various suture passing techniques can be used to accomplish this.
In a 1-anchor repair, 1 suture can passed through In a 1-anchor repair, 1 suture can passed through the labrum posterior to the biceps and the other anterior to the biceps and tied down. Multiple anchors should be used if necessary.

The instrumentation for anchor placement can then be introduced either though the cannula in the anterosuperior portal or percutaneously through the musculotendinous junction of the supraspinatus to form a posterolateral portal. Anchors placed at the biceps root or anterior to it can be inserted through the rotator interval portal. Anchors posterior to the biceps root are best placed in a percutaneous fashion through the port of Wilmington in order to achieve the best trajectory for anchor placement and minimize the risk of anchor perforation through the medial glenoid cortex, which could compromise anchor fixation and potentially injure the suprascapular nerve.

The number of suture anchors used depends on the extent of the tear. Either double- or single-loaded suture anchors may be used. Initially, the more posterior limb of one suture pair is retrieved into and out of the anteroinferior cannula. Various techniques are available by which this suture can then be passed through the labrum.

A common technique is to use a 45° suture lasso that is introduced through the anterosuperior cannula and through which a looped wire can be passed and retrieved through the anteroinferior cannula. The looped wire is then used to shuttle the limb of the suture, which now resides in the anteroinferior cannula, back through the labrum to create a simple stitch through the labrum. Alternatively, both limbs of the suture can be passed to create a mattress stitch.

An arthroscopic knot is tied after both limbs of the anchor suture have been retrieved into the anterosuperior cannula. Care is taken to orient the knot away from the articular surface. When passing the sutures through the labrum, it is important to avoid strangulating the biceps root.

If the anchor is double-loaded, the second suture is then passed through the labrum in a similar fashion and tied down. Knotless anchors with a self-capturing suture loop can also be used for the labral repair.

Ensure that the posterosuperior labrum is adequately stabilized in order to neutralize the peel-back forces. In introducing a posterosuperior anchor, as noted earlier, using a posterolateral portal is usually necessary because the posterosuperior glenoid has a steep angle that makes instrumentation from the more anterior portal difficult. This posterolateral portal can be made without a cannula by passing the sheath for the anchor instruments directly through the rotator cuff at the musculotendinous junction, medial to the rotator cable.

Single-portal SLAP lesion repair is described by Daluga and Daluga. [60]

Postoperative Care

The patient is kept in a sling for 4 weeks. Codman exercises are initiated at week 2. Passive range-of-motion (ROM) exercises, including elevation and external rotation by the side, are also initiated at week 2. No external rotation in abduction is allowed for the first 6 weeks, because of the peel-back mechanism. ROM exercises, including passive posterior capsule and internal rotation stretching, are progressed during weeks 3-6.

At 6 weeks, progressive strengthening of the rotator cuff, scapula stabilizers, biceps, and the deltoid is initiated. Throwing athletes are allowed to begin an interval throwing program at 4 months. At 6 months, throwing from a mound is allowed. Pitchers may resume throwing at full velocity at 7 months postoperatively. Throughout the rehabilitation, as well as after, the patient should continue stretching the posteroinferior capsule daily. A recurrence of the capsular contracture can once again put the shoulder at risk for developing a SLAP lesion.

For nonathletes, the initial 4-month rehabilitation period is identical to that for throwers. At the 4-month mark, they can usually resume full activities.

In 2018, NATA issued a position statement addressing the outcomes of management of SLAP injuries in overhead athletes, along with return-to-play criteria (see Guidelines). [48]

Complications

Neurologic injury is the most common complication reported after arthroscopic shoulder surgery. These complications can be minimized by careful attention to patient positioning, as well as a thorough knowledge of the neurovascular anatomy of the shoulder. When placing the patient in the beach-chair position, ensure that the head and neck are in a neutral position. Either hyperflexion or hyperextension could potentially lead to a neurologic injury.

Suprascapular nerve injury has been a rarely reported complication of superior labral repair. However, there has been a growing awareness of a possible relation between nerve injury and persistent postoperative pain and weakness after SLAP lesion repair. [61Several cadaveric studies have investigated the risk of nerve injury during drilling and anchor insertion.

Koh et al placed an anchor for an anterior SLAP repair (00:30-1:00 o’clock in a right shoulder) via an anterosuperior portal in 12 cadaveric specimens and documented a 100% penetration of the medial glenoid cortex, with four of the 12 anchors directly contacting the suprascapular nerve. [62The average tunnel depth was 14.2 mm, and the average distance from the tunnel exit to the suprascapular nerve was 7.8 mm.

Chan et al performed a similar study in 21 cadaveric specimens (42 paired bilateral shoulders). [63They placed anchors at the 1-, 11-, and 9- to 10-o’clock positions (referencing a right shoulder), corresponding to anterosuperior, high posterosuperior, and low posterosuperior anchors, respectively. The anterosuperior anchor was placed via an anterosuperior portal, whereas the two anchors posterior to the biceps were placed through a posterolateral portal.

They documented a 29% (12/42) perforation rate in placing the anterosuperior anchor with a mean tunnel depth of 18 mm. [63Only one perforation resulted in anchor contact with the suprascapular nerve. The low posterosuperior portal had only a 14% perforation (6/42); however, because of a short mean tunnel distance (11±5 mm), direct contact occurred with the suprascapular nerve in four (66%) of six perforations. Overall, a higher rate of penetration was noted in scapulae of a shorter height. Importantly, no perforations through the medial glenoid wall were noted for the high posterosuperior anchor.

In summary, there appears to be a risk of suprascapular nerve injury associated with drilling and placing anchors in the superior labrum. This may be of greatest concern when anchors are placed through an anterosuperior portal, especially if an attempt is made to place anchors posterior to the biceps through an anterosuperior portal. Anchors posterior to the biceps should be placed through a posterolateral portal.

In the aforementioned cadaveric studies, the bony tunnel length ranged from 5.5-20 mm and the distance from the tunnel exit point to the suprascapular nerve ranged from 4.9 to 11.2 mm. [6362Given that most commercially available anchor systems require drilling to the depth of 18-20 mm and the anchor lengths range from 11 to 14.5 mm, it is certainly possible that both the drill bit and anchor may broach the medial glenoid cortex, increasing the risk of suprascapular nerve injury.

Further research to investigate the use of angled or curved drill guides to help improve tunnel trajectory and bony containment of the anchor, as well as the development of shorter drills and anchors, may be beneficial to minimize the risk of suprascapular nerve injury.

Articular cartilage injury is also of concern. When placing the suture anchors, ensure that the anchors are well seated below the subchondral bone. If the anchors are too prominent, they may cause a chondral injury. The sutures should be tugged on to ensure that the anchors are well seated. Anchor migration, apart from compromising the repair, can result in significant chondral injury.


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