What is the best imaging modality for a suspected torn triceps (triceps brachii)?

From the Guidelines

MRI is the best imaging modality for a suspected torn triceps brachii. When a patient presents with posterior elbow pain, weakness in arm extension, and possibly a palpable defect in the triceps tendon, an MRI should be ordered as it provides excellent soft tissue contrast that can clearly visualize the extent of tendon disruption, muscle retraction, and associated injuries 1.

Key Points to Consider

• Ultrasound is a reasonable alternative that offers real-time dynamic assessment and is less expensive, but it is highly operator-dependent and may not provide the same detailed evaluation of deep tissue structures 1.
• CT scans are less useful for primary diagnosis of triceps tears as they don't visualize soft tissues as well, though they may help identify associated bony avulsions.
• Plain radiographs should be obtained initially to rule out fractures or avulsion fragments but cannot directly visualize the tendon tear itself 1.
• MRI's superior soft tissue resolution allows clinicians to distinguish between partial and complete tears, which is crucial for treatment planning, as complete tears often require surgical repair while partial tears may be managed conservatively 1.

Additional Considerations

• The use of MRI in the assessment of triceps tears has been documented, with studies showing its effectiveness in visualizing the extent of tendon disruption and associated injuries 1.
• The FABS view, a nonstandard imaging view, can be used to assess distal biceps tendon pathology, but its use is not directly applicable to triceps tears 1.
• Ultrasound has been shown to be useful in the evaluation of distal biceps tendon ruptures, but its accuracy is inferior to MRI in detecting partial tears and tendinopathy 1.

From the Research

Imaging Modalities for Suspected Torn Triceps

• Magnetic Resonance Imaging (MRI) is considered the gold standard for diagnosing triceps tendon injuries, including partial and complete tears 2, 3, 4.
• MRI is useful in evaluating the extent of injury, guiding treatment, and confirming physical examination findings 2, 3, 4.
• However, MRI may overestimate the extent of injury, particularly in differentiating between partial- and full-thickness tears 3.
• Axial MR images are more valuable than sagittal images in accurately grading distal biceps tendon injury preoperatively 5.
• While MRI is essential for ascertaining the percentage involvement of the tendon, it may misjudge the size of the tear, and physicians must consider associated comorbidities and patient characteristics when formulating treatment plans 4.

Limitations of MRI

• False-positive MRI assessments of distal triceps injury are not rare, and surgeons should rely on clinical examination in assessing distal triceps tendon injury, with imaging studies providing an adjunctive role in diagnosis and decision-making 3.
• The sensitivity and specificity of MRI for detecting biceps pathology, including partial and full tears, are limited, with high specificity but low sensitivity for full-thickness tears 6.
• The accuracy of MRI in detecting partial tears of the biceps tendon remains limited, with an area under the receiver operating characteristic curve of 0.75 6.

Clinical Correlation

• Clinical correlation is essential in diagnosing triceps tendon injuries, and MRI findings should be interpreted in conjunction with physical examination and patient history 2, 3, 4.
• A high index of suspicion for triceps tendon injury is necessary, particularly in patients with a history of athletic injury, steroid use, or infection 2, 4.