What is a SLAP (Superior Labrum Anterior to Posterior) tear?

SLAP Tear: Understanding Superior Labrum Anterior to Posterior Tears

A SLAP tear is an injury to the superior (top) portion of the labrum in the shoulder that extends from anterior (front) to posterior (back), affecting the attachment site of the biceps tendon to the glenoid. 1

Anatomy and Classification

SLAP tears involve damage to the superior labrum of the shoulder joint, which is a ring of fibrocartilage that surrounds the glenoid (shoulder socket) and helps stabilize the joint. The superior labrum is particularly important as it serves as an anchor point for the long head of the biceps tendon.

SLAP tears are classified into four main types:

• Type I: Fraying of the superior labrum with intact biceps anchor
• Type II: Detachment of the superior labrum and biceps anchor from the glenoid
• Type III: Bucket-handle tear of the superior labrum with intact biceps anchor
• Type IV: Bucket-handle tear of the superior labrum that extends into the biceps tendon 2

Additional extended types (V-X) have been described in the literature to account for more complex tear patterns. 3

Mechanisms of Injury

SLAP tears typically occur through:

1. Acute trauma: Fall onto an outstretched arm with the shoulder in abduction and slight forward flexion 1
2. Repetitive microtrauma: Common in overhead athletes like baseball pitchers
3. Compression forces: Direct impact to the shoulder 3

Clinical Presentation

Patients with SLAP tears commonly present with:

• Pain during overhead activities
• Painful "catching" or "popping" in the shoulder 1
• Pain during overhead pressing movements 4
• Symptoms of instability in some cases
• Decreased performance in throwing athletes

Diagnostic Approach

The American College of Radiology recommends the following imaging approach:

1. Plain radiographs: First-line imaging to rule out fractures and other bony abnormalities 4

2. MR arthrography: Gold standard for detecting labral tears, especially in patients under 35 years of age. It has high sensitivity (86-100%) for labral injury detection and outperforms standard MRI for anterior labral and SLAP tears 5, 4

3. Standard MRI: Highly effective with optimized equipment, especially for detecting associated pathologies like rotator cuff tears 4

4. CT arthrography: Third choice, only if MRI is contraindicated 5, 4

5. Ultrasound: Limited role in labral tear evaluation but useful for associated soft tissue injuries 4

Management Approach

Management should be based on patient characteristics:

1. Non-operative Management (First-line for most patients)

• Scapular stabilization exercises
• Rotator cuff strengthening
• Core strengthening
• NSAIDs for pain and inflammation 4
• Expected to provide symptom relief in approximately 2/3 of patients 6

2. Surgical Management

Surgical intervention should be considered in:

• Patients who fail conservative treatment after 3-6 months
• Patients with significant functional limitations despite therapy
• Young, active patients with high physical demands 4

Surgical options based on patient groups:

For throwing athletes:

• Initial rigorous physical therapy focused on hip, core, and scapular exercise
• If failed, consider SLAP repair with possible PIGHL release 6

For patients with traumatic injury and instability:

• Age <40: SLAP repair
• Age >40: SLAP repair with biceps tenotomy or tenodesis 6

For patients with overuse injury without instability:

• Biceps tenotomy or tenodesis 6

Important Considerations

• MR arthrography is superior to standard MRI for detecting SLAP tears, but selection bias may affect reported sensitivities 5
• Clinical examination tests for labral tears have relatively low sensitivity and specificity, making advanced imaging crucial 4
• Outcomes of arthroscopic repair in older patients are less favorable than in younger patients 7
• SLAP tears are often associated with other shoulder pathologies that may require simultaneous treatment 2

By understanding the nature of SLAP tears and following evidence-based diagnostic and treatment algorithms, clinicians can optimize outcomes and reduce morbidity for patients with this challenging shoulder condition.