What is the Richard Hawkins theory of Superior Labrum Anterior to Posterior (SLAP) tears?

Richard Hawkins Theory of SLAP Tears

The Richard Hawkins theory of SLAP tears proposes that posterior-superior labral tears develop posterior-superior instability that manifests as secondary anterior-inferior pseudolaxity, and that chronic superior instability leads to secondary lesion-location-specific rotator cuff tears that begin as partial thickness tears from inside the joint.

Understanding SLAP Tears

SLAP (Superior Labrum Anterior and Posterior) tears are injuries to the superior labrum that begin posteriorly and extend anteriorly, affecting the anchor of the biceps tendon to the labrum. These lesions were first described by Snyder in 1990 1.

Classification of SLAP Tears

Type II SLAP lesions, which involve detachment of the superior labrum and biceps anchor from the glenoid rim, can be further subdivided into three distinct anatomic subtypes:

• Anterior (37%): Associated with positive Speed and O'Brien tests
• Posterior (31%): Associated with positive Jobe relocation test
• Combined anterior and posterior (31%): Features of both 2

The Hawkins Theory Explained

Hawkins' key observations about Type II SLAP tears include:

1. Posterior-superior instability: SLAP lesions with a posterior component develop posterior-superior instability

2. Secondary anterior-inferior pseudolaxity: This manifests as a "drive-through sign" during arthroscopy (despite absence of anterior-inferior labral pathology)

3. Lesion-location-specific rotator cuff tears: Chronic superior instability leads to secondary rotator cuff tears that:

   • Begin as partial thickness tears from inside the joint
   • Are specific to the location of the SLAP lesion 2

4. Resolution of pseudolaxity: The drive-through sign is eliminated by repair of the posterior component of the SLAP lesion

Clinical Implications

Diagnosis

• Physical examination: Different tests predict different subtypes:

  • Speed and O'Brien tests predict anterior lesions
  • Jobe relocation test predicts posterior lesions 2

• Imaging: MR arthrography is considered the gold standard for detecting labral tears, especially in patients under 35 years of age. Standard MRI without contrast can also be highly effective with optimized imaging equipment 3

Treatment Approach

Treatment should be based on:

1. Type of lesion: Different SLAP types require different approaches
2. Patient age: Younger vs. older patients have different outcomes with repair
3. Activity level: Throwing athletes vs. non-throwing athletes
4. Presence of concomitant lesions: Especially rotator cuff tears 4

Treatment Algorithm for Type II SLAP Tears:

1. Initial conservative management:

   • Scapular exercises
   • Restoration of balanced musculature
   • Expected to provide symptom relief in approximately 2/3 of patients 5

2. For patients with traumatic episode and instability symptoms:

   • Age < 40: SLAP repair
   • Age > 40: SLAP repair with biceps tenotomy or tenodesis 5

3. For patients with overuse etiology without instability:

   • Biceps tenotomy or tenodesis 5

4. For throwing athletes:

   • Rigorous physical therapy focused on hip, core, and scapular exercise
   • Restoration of shoulder motion and rotator cuff balance
   • Surgical intervention only if rehabilitation fails 5

Rehabilitation Approach

If conservative management is chosen, a phased rehabilitation approach is recommended:

• Phase 1: Pain control, gentle range of motion exercises, proper positioning education
• Phase 2: Progressive ROM exercises, light strengthening of rotator cuff and periscapular muscles
• Phase 3: Progressive resistance training, advanced scapular stabilization, and sport-specific training 3

Clinical Pearls and Pitfalls

• Avoid overtreatment: Normal variations and degenerative changes in the SLAP complex must be distinguished from "true" SLAP lesions 4

• Consider age-related outcomes: Results of SLAP repairs in middle-aged and older patients are mixed, with worse outcomes and higher revision rates compared to younger patients 4

• Monitor throwing athletes closely: Results in throwing athletes are less successful, with a significant number unable to regain their pre-injury performance level 4

• Watch for associated pathology: Rotator cuff tears are present in 31% of patients with Type II SLAP lesions and are lesion-location specific 2