SLAP Lesion

History:

• •Deep, poorly localised shoulder pain (often posterior or deep anterior)
• •Mechanical symptoms: clicking, catching, popping, especially with overhead activity
• •Loss of throwing velocity or endurance in overhead athletes - the classic 'dead arm'
• •Specific mechanism: overhead sport, FOOSH, traction, or recent dislocation
• •Pain reproduced by specific positions (behind-the-back reach, late cocking in throwing, overhead lifting)

Examination:

• •Tenderness along the bicipital groove or deep anteriorly
• •O'Brien's active compression test: pain with resisted forward flexion at 90° flexion, 10° adduction, thumb down; relieved with thumb up. For a positive SLAP, the pain must be DEEP. Superficial pain over the ACJ indicates ACJ pathology - most common false positive
• •Speed's test: pain at the bicipital groove with resisted forward flexion in supination
• •Biceps load II (Kim): pain or apprehension with resisted elbow flexion at 120° abduction
• •Isolated infraspinatus weakness or atrophy: consider a paralabral cyst in the spinoglenoid notch compressing the suprascapular nerve (most common with posterior-extending type II)
• •Assess coexisting pathology: cuff (Jobe's, ER strength), instability, GIRD
• •No single test is diagnostic; clustering raises suspicion but imaging is required

Red flags:

• •Acute traumatic dislocation with failed reduction or neurovascular compromise
• •Sudden loss of motor function (axillary nerve injury after dislocation)
• •Associated fracture
• •Progressive infraspinatus weakness or atrophy suggesting compressive paralabral cyst

Plain radiographs (first-line): typically normal in isolated SLAP; used to exclude bony Bankart, Hill-Sachs, HAGL avulsion, fracture, or glenohumeral OA.

MR arthrography (MRA): preferred and most accurate for suspected SLAP. Intra-articular gadolinium outlines the superior labrum and biceps anchor; sensitivity and specificity substantially better than conventional MRI. Also identifies associated paralabral cysts.

Conventional MRI: lower sensitivity for SLAP than MRA, particularly for subtle type II tears. Useful for screening and identifying associated cuff or bone pathology. A normal conventional MRI does not exclude SLAP - if clinical suspicion remains high, request MRA.

Imaging pitfalls:

• •Normal anatomical variants (sublabral recess, sublabral foramen, Buford complex) can mimic type II SLAP on MRA - correlate with symptoms and examination
• •An imaging-defined SLAP is not automatically the primary pain generator, particularly over 40

Arthroscopy: reference standard, but invasive. Usually undertaken when operative treatment is being considered.

Most patients should have a structured non-operative trial first; surgery is reserved for refractory symptoms, high-demand overhead athletes with targeted subtypes, or clear surgical indications.

Non-operative (first-line):

• •Typical duration 3-6 months
• •Relative rest from provocative positions (overhead reach, throwing, heavy bench press)
• •Physiotherapy: scapular control, posterior capsule stretching for GIRD, cuff strengthening, graded return to overhead loading
• •Analgesia: paracetamol, NSAIDs as adjunct
• •Subacromial or glenohumeral corticosteroid injection has a limited role
• •Up to 50-70% of recreational athletes improve and avoid surgery

Surgical options (when non-op fails or specific indications present):

• •Type I: arthroscopic debridement
• •Type II: SLAP repair OR biceps tenodesis. Current UK practice favours tenodesis in patients over ~35-40, manual workers, and those with coexisting LHBT pathology - comparable outcomes with lower postoperative stiffness and reoperation
• •Type III: arthroscopic debridement (biceps anchor intact)
• •Type IV: debridement or tenodesis depending on biceps tendon involvement

Biceps tenodesis vs tenotomy:

• •Tenodesis: releases LHBT from labrum and fixes to humerus, preserving length-tension
• •Tenotomy: simple release without fixation; shorter operative time, lower morbidity, no implant. 'Popeye' deformity in a minority. Often offered to older (>55-60) or lower-demand patients
• •Paralabral cysts: usually decompressed at time of labral repair

Referral: routine specialist referral when non-op fails, high-demand overhead athletes with positive exam + MRA, or isolated infraspinatus weakness suggesting paralabral cyst.

Non-operative pathway:

• •Phase 1 (0-6 weeks): pain control, scapular setting, posture correction, avoid provocative positions
• •Phase 2 (6-12 weeks): progressive cuff strengthening, posterior capsule stretching for GIRD, gradual return to horizontal-plane loading
• •Phase 3 (>12 weeks): sport-specific drills, progressive return to overhead loading. Return to unrestricted overhead sport typically 4-6 months

Post-operative (SLAP repair):

• •Sling 4-6 weeks with protected passive ROM
• •Active-assisted ROM from weeks 4-6
• •Strengthening from 8-12 weeks
• •Throwing programme typically from 4-6 months
• •Return to competitive overhead or contact sport typically 6-9 months, guided by the operating team

Post-operative (biceps tenodesis or tenotomy):

• •Similar sling and ROM protocol but strengthening progression often slightly faster (biceps anchor no longer loaded)
• •Return to overhead sport typically 4-6 months

Overhead athletes may not always regain prior performance even after technically successful surgery.

• •Snyder classification (I-IV) - The framework that drives SLAP management; type II accounts for ~50% of all SLAP lesions and most often requires surgical consideration.
• •Peel-back mechanism (Burkhart) - The biomechanical explanation for posterior-extending type II lesions in throwing athletes; informs imaging interpretation and surgical planning.
• •Modern UK shoulder practice (BESS) - Most SLAP patients are offered structured non-operative treatment first; surgery is reserved for refractory symptoms or specific subgroups.
• •Tenodesis-over-repair shift - In patients over ~35-40, manual workers, and those with coexisting LHBT pathology, biceps tenodesis offers comparable outcomes with lower rates of postoperative stiffness and reoperation than primary SLAP repair.
• •MR arthrography - The preferred imaging modality; normal conventional MRI does not exclude SLAP. Anatomical variants (sublabral recess or foramen, Buford complex) can mimic type II on MRA.

• •O'Brien's test: for a positive SLAP, the pain must be felt DEEP in the shoulder. Superficial pain over the ACJ indicates ACJ pathology - the classic false positive.
• •Isolated infraspinatus weakness or atrophy = think paralabral cyst in the spinoglenoid notch compressing the suprascapular nerve, most often associated with posterior-extending type II lesions.
• •An imaging-defined SLAP is not automatically the primary pain generator, particularly in patients over 40 where coexisting cuff or biceps tendon pathology may dominate the clinical picture.
• •Biceps tenodesis is increasingly preferred over SLAP repair in patients over ~35-40, manual workers, and those with coexisting LHBT pathology - comparable outcomes with lower stiffness and reoperation rates.
• •'Dead arm' in a throwing athlete with loss of velocity is a classic SLAP stem clue.
• •Combined Bankart + SLAP lesions are common after anterior dislocation in contact sport - consider both when imaging the shoulder of an in-season contact athlete.