Would an MRI help differentiate the causes of medial elbow pain with snapping and swelling?

MRI for Differentiating Causes of Medial Elbow Pain with Snapping and Swelling

MRI is highly effective for differentiating causes of medial elbow pain with snapping and swelling, particularly when radiographs are normal or nonspecific. 1

Initial Imaging Approach

• Radiography should be the initial imaging modality for chronic elbow pain to identify potential bony abnormalities, heterotopic ossification, osteochondral lesions, or soft tissue calcification 1
• When radiographs are normal or nonspecific in patients with medial elbow pain with snapping and swelling, advanced imaging is indicated 1

MRI Benefits for Medial Elbow Pain with Snapping

MRI provides several advantages for evaluating medial elbow pain with snapping and swelling:

• Superior visualization of soft tissue structures including muscles, ligaments, tendons, nerves, bone marrow, and hyaline cartilage 2
• High sensitivity for detecting common causes of medial elbow pain including:
  • Medial epicondylitis (golfer's elbow) with characteristic T2 signal changes in the common flexor tendon and paratendinous soft tissue edema 1
  • Ulnar collateral ligament injuries with reported sensitivity of 90-100% 1
  • Snapping triceps syndrome, which can cause medial elbow pain with snapping 1
  • Ulnar nerve entrapment/neuropathy with findings of high signal intensity and nerve enlargement 1
  • Anconeus epitrochlearis muscle (a known cause of medial elbow pain with snapping in overhead athletes) 3

Specific MRI Findings for Snapping Elbow

• T2-weighted MR neurography is considered the reference standard for imaging ulnar nerve entrapment, which can present with snapping and medial elbow pain 1
• MRI can demonstrate recurrent ulnar nerve dislocation causing snapping symptoms 1
• Dynamic evaluation of the medial head of the triceps can reveal snapping triceps syndrome 1
• MRI can identify the presence of an anconeus epitrochlearis muscle, which may cause snapping and compression of the ulnar nerve 3

Advantages of MRI Over Other Modalities

• More accurate than non-contrast imaging for detecting collateral ligament injuries 1
• Can simultaneously evaluate multiple potential causes of medial elbow pain including tendinopathy, ligament injuries, nerve entrapment, and joint effusion 4, 5
• Provides comprehensive assessment of bone marrow edema, which may indicate stress reactions not visible on radiographs 1
• Allows visualization of associated soft tissue injuries that may contribute to symptoms 1, 2

When to Consider Alternatives to MRI

• Ultrasound may be considered as an alternative when dynamic evaluation is specifically needed to visualize snapping structures in real-time 6
• CT may be useful when detailed bony anatomy is required, particularly for complex fracture patterns 1
• For suspected ulnar neuropathy with snapping, dynamic ultrasound can demonstrate nerve dislocation during elbow movement 1, 6

Common Pitfalls and Caveats

• MRI without contrast may be insufficient for complete evaluation of collateral ligament injuries; MR arthrography may provide better accuracy at 3T 1
• Isolated evaluation of a single structure may miss concomitant pathologies that often occur together in medial elbow pain 1, 2
• Normal anatomic variants (such as the T sign of the UCL) may be misinterpreted as pathologic 1
• MRI should be interpreted in conjunction with clinical findings, as some abnormalities may be incidental and not the source of symptoms 5