What is the role of MRI (Magnetic Resonance Imaging) in evaluating scapulothoracic dyskinesis?

Role of MRI in Evaluating Scapulothoracic Dyskinesis

MRI is not typically used as a first-line imaging modality for scapulothoracic dyskinesis but can be valuable in identifying underlying inflammatory processes and soft tissue abnormalities when standard evaluation methods are inconclusive.

Understanding Scapulothoracic Dyskinesis

Scapulothoracic dyskinesis (SD) refers to altered positioning and abnormal movement patterns of the scapula during shoulder motion. It is characterized by:

• Disruption in normal scapular position and motion during shoulder movements
• Commonly seen in overhead athletes (baseball, tennis, swimming)
• Often coexists with other shoulder pathologies
• Can cause significant pain and functional limitations

Diagnostic Approach for Scapulothoracic Dyskinesis

First-Line Diagnostic Methods

1. Clinical Examination:

   • Visual observation of scapular movement
   • Scapular assistance test
   • Scapular retraction test
   • Assessment of periscapular muscle function

2. Plain Radiography:

   • Standard shoulder radiographs to evaluate bony anatomy
   • Radiography is the first imaging modality for shoulder evaluation 1
   • Can detect scapular fractures, especially in patients with reverse shoulder prostheses

Role of MRI in Scapulothoracic Dyskinesis

MRI becomes valuable in specific scenarios:

1. When to Consider MRI:

   • After inconclusive initial evaluation with clinical examination and radiographs
   • When suspecting underlying soft tissue pathology
   • To evaluate for concomitant shoulder conditions (rotator cuff tears, labral injuries)
   • When symptoms persist despite conservative management

2. What MRI Can Detect:

   • Inflammation adjacent to bony deformities 2
   • Soft tissue abnormalities in the subscapular fossa 2
   • Periscapular muscle abnormalities (atrophy, tears, edema)
   • Associated shoulder pathologies (rotator cuff tears, labral injuries)
   • Bursitis around the scapulothoracic articulation

3. MRI Protocol Considerations:

   • Fluid-sensitive sequences are important to identify inflammation 2
   • Coverage should include the entire scapula and surrounding soft tissues
   • Metal reduction protocols may be necessary if hardware is present 1
   • Orthogonal views through oblique planes of the shoulder region 1

Clinical Application and Limitations

Benefits of MRI

• Provides detailed soft tissue evaluation not possible with other modalities
• Can confirm the etiology of scapular dyskinesis when bony deformities are present 2
• Helps differentiate between primary scapular dyskinesis and secondary forms due to other shoulder pathologies
• Can guide treatment decisions, particularly when considering surgical intervention

Limitations

• Not typically ordered as a first-line study for evaluation of shoulder pain 1
• May detect incidental findings unrelated to symptoms
• Cost and accessibility considerations
• Limited value without correlation to clinical findings

Treatment Implications

The management approach to scapulothoracic dyskinesis depends on MRI findings:

1. Conservative Management (First-line approach):

   • Physical therapy focused on scapular stabilization
   • Periscapular muscle strengthening
   • Correction of movement patterns
   • Activity modification

2. Surgical Intervention (Based on MRI findings):

   • Considered when MRI identifies specific pathology requiring surgery
   • Arthroscopic debridement for inflammatory lesions 2
   • Addressing concomitant pathologies (rotator cuff repair, labral repair)

Common Pitfalls

• Relying solely on imaging without clinical correlation
• Attributing symptoms to incidental findings on MRI
• Failure to evaluate the entire kinetic chain
• Not considering scapular dyskinesis when evaluating other shoulder pathologies
• Overlooking the contribution of scapular dyskinesis to shoulder dysfunction

MRI should be used as part of a comprehensive evaluation that includes clinical assessment and plain radiography, with the understanding that findings must be correlated with the patient's clinical presentation to guide appropriate management decisions.