What imaging modality is recommended for medial epicondyle tendonitis?

Imaging Modalities for Medial Epicondyle Tendonitis

MRI without IV contrast is the recommended imaging modality for medial epicondyle tendonitis when clinical diagnosis is inconclusive or symptoms persist despite treatment. 1

Initial Approach

• Radiography should be performed as the initial imaging study to rule out bony abnormalities, though it typically cannot demonstrate soft tissue changes of tendinopathy 1
• Plain radiographs may show osteophyte formation at the epicondyles, degenerative joint disease, loose bodies, or fractures, but are limited in evaluating tendon pathology 1

Recommended Advanced Imaging

When radiographs are normal or show nonspecific findings and tendon pathology is suspected:

MRI

• MRI without IV contrast is the preferred advanced imaging modality for medial epicondyle tendonitis 1
• MRI demonstrates high inter- and intraobserver reliability for the diagnosis of epicondylalgia 1
• The most specific findings of medial epicondylitis on MRI include:
  • Intermediate to high T2 signal within the common flexor tendon 1, 2
  • Paratendinous soft tissue edema 1, 2
  • Thickening of the common flexor tendon 2
• MRI has the benefit of demonstrating associated findings such as radial collateral and lateral ulnar collateral ligament injuries 1
• MRI may facilitate surgical planning by accurately identifying the extent of tendon damage 1, 3

Ultrasound

• Ultrasound is an alternative imaging option for medial epicondyle tendonitis 1
• Ultrasound shows high diagnostic accuracy with sensitivity of 95.2%, specificity of 92%, and accuracy of 93.5% for medial epicondylitis 1, 4
• Advantages of ultrasound include:
  • Ability to dynamically assess tendons 1
  • Lower cost compared to MRI 4
  • Can guide interventional procedures if needed 1
• Ultrasound can detect:
  • Focal hypoechoic or anechoic areas in the tendon 4
  • Tendon nonvisualization 4
  • Intratendinous calcifications 4
  • Cortical irregularity 4

Imaging Algorithm

1. Start with plain radiographs to rule out bony pathology 1
2. If radiographs are normal or show nonspecific findings and clinical suspicion for medial epicondyle tendonitis persists:
   • MRI without IV contrast is the preferred next imaging study 1
   • Ultrasound is an acceptable alternative, particularly when:
     • Dynamic assessment is needed 1
     • Cost is a concern 4
     • Image-guided intervention is being considered 1

Common Pitfalls and Considerations

• CT and CT arthrography have limited evidence to support their use for detection of tendon tears or chronic epicondylalgia 1
• MR arthrography does not add additional information compared to non-contrast MRI for epicondylalgia 1
• Bone scans are not routinely used for evaluation of suspected tendon abnormality 1
• Pronation weakness at 90° is a critical physical examination finding that correlates with pathologic changes seen on imaging 3
• Consider that medial epicondylitis predominantly affects the dominant arm in most cases 5