It’s all in the Head
Author: Tabitha Ford, MD
Peer-reviewer: Will Denq, MD CAQ-SM
Final Editor: Alex Tomesch, MD CAQ-SM
A 47 year-old female sustains a mechanical fall on ice, and reaches out to catch herself with her hand. Afterwards, she complained of elbow pain.
Image 1. AP and Lateral x-ray of the elbow, courtesy of Dr. Matthew Negaard
What is the diagnosis?
Radial head break (fracture)
- Pearl: Classic mechanism is a FOOSH with elbow in extension and forearm in pronation
Image 2. Annotated x-ray from above, Courtesy of Dr. Matthew Negaard. Annotation by Dr. Alex Tomesch
What additional view can you obtain on XR?
Ordering a radiocapitellar view may reveal a nondisplaced radial head fracture or capitellar fractures.
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Pearl: Findings on x-ray indicative of radial head fracture include:
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Remember, posterior fat pad should never be visible
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Anterior fat pad may be visualized in normal elbows, but is often shaped like a sail when an effusion is present
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Fat pad abnormalities on lateral elbow film
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Can sometimes visualize the fracture, but they can be very subtle
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If you see fat pad abnormality (Image 3 and 4) without visible fracture, treat as a radial head
Image 3. Anterior sail sign (yellow and blue) suggest elbow effusion and occult fracture. Courtesy of Dr. Frank Galliard, Radiopaedia.org, rRID: 18084
Image 4. Posterior fat pad sign (indicated by arrow). Courtesy of Dr. Frank Gaillard, Radiopaedia.org, rRID: 3578. Annotation by Dr. Alex Tomesch.
References
[1] Raby N, Berman L, Morley S, de Lacey G. Accident & Emergency Radiology: A survival guide. 3rd ed. Elsevier Limited; 2015.
[2] Geiderman J, Torbati S, Mayer T. Humerus and elbow. In: Marx J, ed. Rosen's Emergency Medicine Concepts and Clinical Practice. 8th ed. Philadelphia, PA: Elsevier, Saunders; 2014: 596-617.e1
[3] Goldflam K. Evaluation and treatment of the elbow and forearm injuries in the emergency department. Emerg Med Clin N Am. 2015;33(2): 409-421. doi: 10.1016/j.emc.2014.12.010