Glenoid Labral Tears/SLAP Lesions

By admin On Sep 17, 2023

Ovid: 5-Minute Sports Medicine Consult, The

Aaron V. Mares

Tanya J. Hagen

Basics

Glenohumeral joint is a dynamic spheroid (‘ball and socket’) articulation:
- The glenoid labrum, in addition to the glenohumeral ligaments, the rotator cuff, and the scapular rotators, provide joint stability.
The labrum is a fibrocartilaginous “lip” that surrounds the circumference of the glenoid fossa:
- Increases the depth and surface area of the joint, increasing joint stability
- The long head of the biceps brachii attaches to the superior portion of the labrum.
Because of the mechanisms of injury involved, superior tears (“SLAP” lesions) and anterior-inferior tears (Bankart lesions) are more common than posterior labral tears.

Description

SLAP lesions (superior labrum anterior posterior lesions):
- Typically caused by repetitive overhead motion (eg, baseball pitcher in late cocking phase) or from a fall onto an outstretched arm
- Presently, 10 types of lesions are described by some experts.
- Traditionally, there have been 4 main types of lesions as listed:
  - Type I: Fraying or degeneration of the superior capsulolabral structures sparing the origin of the biceps brachii tendon (long head); joint remains stable.
  - Type II: Detachment of superior labrum and the origin of the long head of the biceps brachii tendon (most common)
  - Type III: Bucket-handle tear of the superior labrum sparing the origin of the biceps brachii tendon (long head)
  - Type IV: Bucket-handle tear of the superior labrum as well as the origin of the biceps brachii tendon (long head).
Bankart lesions:
- Usually involve anterior and inferior portion of the glenoid labrum
- Typically caused by anterior shoulder instability
- May be associated with a fracture of the glenoid rim (“bony Bankart”)

Epidemiology

In addition to labral tears, common shoulder injuries in sports include:
- Glenohumeral dislocation
- Acromioclavicular separation
- Rotator cuff contusions/tendonitis/tear
- Fractures
Glenoid labral tears frequently occur in combination with other shoulder injuries.

Incidence

SLAP lesions: Reported rates range from 6–20%
Bankart lesions: When associated with acute anterior dislocation, reported rates up to 78% incidence and with chronic instability up to 93% (1)

Risk Factors

Repetitive overhead motion (sports or occupational):
- Baseball (pitchers)
- Football (quarterbacks)
- Weight lifters (military press)
- Swimmers
- Tennis
Shoulder instability/trauma
Anatomic variation (eg, Buford complex) or underlying generalized laxity/instability

General Prevention

Per USA Swimming and the Network Task Force on Injury Prevention (2002):

Stretching (eg, capsular stretch in throwers with “GIRD” = glenohumeral internal rotation deficiency)
Rotator cuff and periscapular strengthening
Core strength training
Ensure proper overhead (throwing/swimming, etc.) mechanics.

Etiology

Mechanisms of injury to the glenoid labrum are acute trauma and repetitive microtrauma from overhead activity:

Acute: Trauma:
- Shoulder dislocation/subluxation: Anterior → Bankart, posterior (less common, eg, blocking football lineman) → posterior labral tear/“reverse Bankart”
- Falling on an outstretched arm
- Abrupt jerk on the upper extremity:
  - Traction when breaking a fall
  - Sudden pull on the arm (ie, when trying to lift a heavy object)
Chronic: Microtrauma:
- Secondary to repetitive overhead shoulder motion
- SLAP lesions typically occur in overhead athletes during acceleration in the late cocking phase.
- Chronic instability, without true traumatic dislocation, can cause labral tearing.

Commonly Associated Conditions

Labral tears can be associated with other, underlying shoulder problems and anatomic variability. In addition, forces that cause labral tearing can cause other injury. Finally, there are frequently secondary problems that may arise as a result of labral tears.
Conditions that may be found in conjunction with labral tears include but are not limited to (1):
- Instability
- Bony injury (particularly in the setting of traumatic dislocation): Bony Bankart, Hill Sacks
- Rotator cuff injury, tendinosis, impingement
- Internal impingement, glenohumeral internal rotation deficiency
- Ganglion cysts
- Buford complex
- Scapulothoracic dysrhythmia

Diagnosis

The diagnosis of a glenoid labral tear is made by history, physical, and appropriate imaging. Occasionally, arthroscopy is necessary for definitive diagnosis.

History

Most individuals complain of nonspecific shoulder pain. Location depends on the site of the tear.
Persons with SLAP lesions most commonly complain of anterior/superior shoulder pain.
Other pertinent positives in the history may include:
- Acute trauma or repetitive motion (sport, hobby, occupational)
- Mechanical symptoms: “Click, pop, or catch” with circumferential motion
- Decrease in athletic performance (strength, velocity, accuracy, precision)
- Weakness in the upper extremity
- Sense of instability

Physical Exam

Numerous examination techniques have been described, but no single test is both sensitive and specific enough to accurately diagnose glenoid labral tears (2)[A].
A study by Parentis and colleagues in 2006 found that the O'Brien's active compression test, Jobe test, Speed's test, Hawkins test, and Neer's test were the most sensitive, though not specific, in the evaluation for SLAP lesions (3)[B].
Other exam findings will depend on associated issues (instability, RTC weakness, etc).

Examples of commonly used labral exam techniques:

Labral “clunk” test:
- Original test for glenoid labral tears 1st described in the 1980s
- Patient lies supine with examiner abducting the shoulder past 90 degrees with one hand while pressing the proximal humeral head anteriorly. The clinician then internally and externally rotates the shoulder.
- (+) test = pain or catch prior to a “click” felt by the patient
O'Brien's active compression test:
- Examiner resists forward flexion while the patient's arm is flexed to 90 degrees and adducted 15 degrees across midline. Initially, the shoulder is internally rotated (thumb down) and then externally rotated (palm up).
- (+) test = pain that improves with external rotation (palm up)
Speed's test:
- Examiner resists forward flexion while the patient's arm is flexed to 90 degrees, externally rotated (palm up), with the elbow in full extension.
- (+) test = pain experienced at the proximal biceps with resistance

Diagnostic Tests & Interpretation

Because the physical exam is both nonsensitive and nonspecific, imaging (x-ray and MRI arthrogram) is frequently relied upon for definitive diagnosis when the history and physical is suggestive.

Imaging

Plain radiographs:
- Aid in ruling out other pathology, such as fractures, calcific tendinitis, and degenerative joint disease
- Minimum 3 views: True AP of glenohumeral joint, axillary lateral, outlet view:
  
  P.275
  - Consider other “instability” views as appropriate: Stryker notch view, west point axillary lateral, etc.
MR arthrogram (4)[A]:
- Labral pathology best appreciated on coronal oblique sequences
- Sensitivity 82–100%, specificity 71–98%
- At most centers, MR arthrography provides improved sensitivity (without loss of specificity) when compared to MRI without intra-articular contrast.

Diagnostic Procedures/Surgery

Glenohumeral arthroscopy:

Gold standard
Most sensitive and specific test for labral pathology

Differential Diagnosis

Instability (traumatic/atraumatic)
Rotator cuff contusion/tendinitis/tear, impingement
Bicipital tendinitis/rupture (long head)
Arthritis (osteoarthritis, inflammatory, crystalline arthropathies)
Cervical radiculopathy and other referred pain
Septic joint
Pain syndromes (complex regional pain syndrome, Parsonage Turner)

Treatment

Current recommendations support an initial conservative approach, but depending on location and degree of injury, surgery is often required:

Initial therapy (nonoperative) (5)[B]:
- Relative rest from overhead/aggravating activity
- Pain management: Ice, NSAIDs, acetaminophen
- Physical therapy to improve strength and flexibility and to address predisposing/associated issues (eg, scapulothoracic dysrhythmia in patients with instability or capsular tightness in patients with GIRD)
- Evaluate and address underlying biomechanical problems (eg, kinetic chain/core weakness in thrower).

Medication

Pain control: NSAIDs or acetaminophen
In the setting of associated impingement, a subacromial corticosteroid injection could be considered.

Additional Treatment

A brace that limits shoulder motion may be of some value to athletes attempting to “get through a season.” The efficacy of such brace use depends on many factors, including type and severity of lesion, sport, and position. It should be noted that there is no current research to support this.

Surgery/Other Procedures

Surgical repair and/or debridement for the majority of labral tears is definitive therapy when nonoperative management fails.
The decision to repair (vs debridement) is primarily based on the degree of injury, specifically for SLAP tears, whether there is significant capsuloligamentous detachment.
Surgical intervention may include:
- Labral debridement
- Labral repair (stapling, suture anchors, biodegradable implants)
- Subacromial decompression
- Acromioplasty
- Cyst decompression
- Biceps tenotomy
Other intervention may be required depending on associated conditions such as rotator cuff tears or instability.

Ongoing Care

Postoperative care varies among individuals and depends on overall surgical intervention.
Example of postoperative care after a posterior portal approach (5)[C]:
- Immobilization in a sling for 4 wks
- Elbow and wrist range of motion exercises immediately
- Resistance strength exercises at 3 mos postoperatively
- Avoidance of extreme positions of abduction and external rotation during the 1st 3 mos
- Initiation of formal throwing in overhead athletes at 4 mos
- Typical return to full throwing by 9–12 mos

Follow-Up Recommendations

Rigorous follow-up is recommended.

Prognosis

Bendi and colleagues reviewed recent data and reported a 63–94% satisfaction score in symptoms after surgical intervention, with 45–96% returning to their pre-injury level of performance, depending on the extent of injury and surgical intervention required (debridement vs comprehensive surgery) (5)[A].

Complications

Potential complications for labral tears that are treated both operatively and nonoperatively include:
- Occult instability
- Persistent pain
- Chondral injury
- Adhesive capsulitis
Operative complications may include (in addition to those listed above):
- Synovitis
- Infection
- Hemarthrosis
- Mechanical failure
- Broken or dislodged tack/suture
- Chondrolysis

References

1. Yiannakopoulos CK, Mataragas E, Antonogiannakis E. A comparison of the spectrum of intra-articular lesions in acute and chronic anterior shoulder instability. Arthroscopy. 2007;23:985–990.

2. Hegedus EJ, Goode A, Campbell S, et al. Physical Examination Tests of the Shoulder: A Systematic Review with Meta-analysis of Individual Tests. Br J Sports Med. 2007.

3. Parentis MA, Glousman RE, Mohr KS, et al. An evaluation of the provocative tests for superior labral anterior posterior lesions. Am J Sports Med. 2006;34:265–268.

4. Chang D, Mohana-Borges A, Borso M, et al. SLAP lesions: Anatomy, clinical presentation, MR imaging diagnosis and characterization. Eur J Radiol. 2008.

5. Bedi A, Allen AA. Superior labral lesions anterior to posterior-evaluation and arthroscopic management. Clin Sports Med. 2008;27:607–630.

Additional Reading

McKeag, DB, Moeller JL. ACSM's Primary care sports medicine. Philadelphia: Lippincott Williams & Wilkins, 2007.

McMahon PJ, ed. Current diagnosis & treatment in sports medicine. New York: Lange Medical Books/McGraw Hill Medical Pub., 2007.

Sallis RE, Massimino F, eds. Essentials of sports medicine. St. Louis: Mosby-Year Book, 1997.