What is the approach to diagnosing and managing Teres major pathology contributing to shoulder pain?

Diagnosing and Managing Teres Major Pathology in Shoulder Pain

MRI is the preferred imaging modality for diagnosing teres major pathology contributing to shoulder pain, with MR arthrography being particularly valuable for assessing associated intra-articular pathology. 1

Clinical Presentation and Evaluation

Key Clinical Findings

• Pain during throwing actions or overhead activities
• Limited internal rotation of the shoulder
• Decreased tissue extensibility
• Pain with specific movements that engage the teres major muscle
• Potential weakness in shoulder adduction and internal rotation

Initial Assessment

1. Radiographs: Start with standard shoulder radiographs to rule out bony abnormalities

   • Should include at least 3 views with 2 being orthogonal 1
   • AP view, axillary lateral view, and scapular Y view are recommended

2. Physical Examination Tests:

   • Assess for tenderness over the teres major muscle (posterior axillary fold)
   • Evaluate pain with resisted adduction and internal rotation
   • Check for active myofascial trigger points in the teres major
   • Assess internal rotation range of motion limitations

Advanced Imaging

MRI

• First-line advanced imaging for teres major pathology when radiographs are noncontributory 1
• Provides excellent visualization of:
  • Muscle tears or strains
  • Tendinopathy
  • Edema within the muscle belly
  • Associated rotator cuff pathology

MR Arthrography

• Highest rated imaging modality (9/9) for suspected labral tears or instability that may accompany teres major pathology 1
• Superior for detecting:
  • Partial-thickness tears
  • Labral pathology
  • Intra-articular soft tissue injuries

Ultrasound

• Limited role in isolated teres major assessment
• May be useful for:
  • Guided interventions (injections, dry needling)
  • Dynamic assessment of muscle function
• Less effective than MRI for comprehensive evaluation 1

Treatment Approach

Conservative Management

1. Physical Therapy:

   • Focused on improving internal rotation ROM
   • Stretching exercises for teres major extensibility
   • Strengthening of surrounding musculature
   • Correction of biomechanical abnormalities

2. Interventional Procedures:

   • Dry Needling: Shown to be effective for active myofascial trigger points in teres major
     • Significant improvements in pain intensity, internal rotation ROM, and tissue extensibility 2
   • Injections: Consider ultrasound-guided injections for persistent pain
     • Local anesthetic with or without corticosteroid

Surgical Management

• Reserved for cases refractory to conservative treatment or with specific indications:

1. Teres Major Tendon Transfer:

   • Effective for irreparable posterosuperior rotator cuff tears
   • Provides long-term improvement in shoulder function and pain reduction
   • Shown to maintain benefits at 8-12 years follow-up 3

2. Combined Procedures:

   • Latissimus dorsi and teres major tendon transfers with reverse shoulder arthroplasty
   • Indicated for posterosuperior cuff dysfunction with external rotation deficits
   • Improves active forward flexion and external rotation while reducing pain 4

Treatment Algorithm

1. Initial Presentation:

   • Radiographs + clinical examination
   • If negative radiographs but clinical suspicion remains → MRI

2. Based on MRI Findings:

   • Isolated teres major pathology → Conservative management for 6-12 weeks
   • Associated labral or intra-articular pathology → Consider MR arthrography for further evaluation

3. For Persistent Symptoms:

   • Trial of dry needling or injection therapy
   • If symptoms persist → Surgical consultation

Important Considerations

• Teres major pathology often coexists with other shoulder conditions (rotator cuff tears, labral injuries)
• Accurate diagnosis requires correlation of imaging findings with clinical presentation
• Surgical options should be reserved for cases that fail appropriate conservative management
• In athletes, particularly those involved in throwing sports, addressing biomechanical factors is crucial for successful outcomes

Pitfalls to Avoid

• Overlooking teres major involvement in posterior shoulder pain
• Focusing solely on rotator cuff pathology without assessing other posterior shoulder muscles
• Inadequate imaging (using only radiographs when soft tissue pathology is suspected)
• Failing to consider teres major tendon transfer as an option for irreparable rotator cuff tears