Elbow x-ray: Difference between revisions

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==Four Questions==
==Four Questions==
[[File:Ant and post fat pad.png|thumb|Anterior and posterior fat pad signs.]]
[[File:Ant and post fat pad.png|thumb|Anterior and posterior fat pad signs (in a case of an undisplaced fracture of the radius head which is not visible directly).]]
# Are the fat pads normal?
[[File:AnteriorFatPad (normal).png|thumb|A normal anterior fat pad in a non-fractured arm.]]
## A visible ant. fat pad is normal but if displaced anteriorly (Sail sign) it is abnormal
[[File:Elbow ant fat pad.jpg|thumb|Anterior "Sail sign"]]
## A visible post. fat pad is always abnormal
[[File:Elbowalignment.png|thumb|Normal pediatric elbow alignment]]
## What if have fat pad displacement but no fx or displacement is identified?
#Are the fat pads normal?
### Adults: Treat as radial head fx
#*A visible ant. fat pad is normal but if displaced anteriorly (Sail sign) it is abnormal
### Peds: Be certain that neither an undisplaced supracondylar fx nor a displaced internal epicondyle fx is overlooked!  
#*A visible post. fat pad is always abnormal
# Is the radiocapitellar line normal?
#*What if have fat pad displacement but no fracture or displacement is identified?
## A line drawn along the longitudinal axis of the radial head and neck should pass through the capitellum
#**Adults: Treat as radial head fracture
### If line does not pass through capitellum then dislocation of radial head is probable
#**Peds: Be certain that neither an undisplaced supracondylar fracture nor a displaced internal epicondyle fracture is overlooked!  
## Whenver there is a fx of the ulnar shaft must evaluate the radiocapitellar line for poss radial head dislocation (Monteggia fx dislocation)
#Is the radiocapitellar line normal?
## This rule is always valid on a true lateral film
#*A line drawn along the longitudinal axis of the radial head and neck should pass through the capitellum
### In peds cases the AP view may be misleading
#**If line does not pass through capitellum then [[radial head dislocation|dislocation of radial head]] is probable
# Is the anterior humeral line normal?
#*Whenever there is a fracture of the ulnar shaft must evaluate the radiocapitellar line for possible [[radial head dislocation]] ([[Monteggia fracture-dislocation]])
## A line drawn along the ant cortex of the humerus will have at leats 1/3 of the capitellum anterior to it
#*This rule is always valid on a true lateral film
### If less than 1/3 then strong probability of supracondylar fx w/ distal fragment displaced posteriorly  
#**In pediatric cases the AP view may be misleading
# Are the ossification centers normal?
#Is the anterior humeral line normal?
## CRITOE (Capitellum, Radial head, Internal epicondyle, Trochlea, Olecranon, Lateral Epicondyle)
#*A line drawn along the ant cortex of the humerus will have at least 1/3 of the capitellum anterior to it
### Dislocated elbow may result in avulsion of internal epicondyle  
#**If less than 1/3 then strong probability of [[supracondylar fracture]] with distal fragment displaced posteriorly  
#### Because the trochlea ossifies after the internal epicondyle if you see the trochlea you must find the epicondyle!
#Are the ossification centers normal (pediatric patients only)?
#*[[CRITOE]] (Capitellum, Radial head, Internal epicondyle, Trochlea, Olecranon, Lateral Epicondyle)
#**[[elbow dislocation|Dislocated elbow]] may result in avulsion of internal epicondyle  
#***Because the trochlea ossifies after the internal epicondyle if you see the trochlea you must find the epicondyle!
 
{{Elbow ossification by age DDX}}


==See Also==
==See Also==
*[[Elbow Diagnoses]]
*[[Elbow diagnoses]]
*[[Elbow X-ray (Peds)]]
*[[Elbow fractures (peds)]]


==Source==
==References==
*Accident and Emergency Radiology
*Accident and Emergency Radiology


[[Category:Rads]]
[[Category:Radiology]]
[[Category:Pediatrics]]
[[Category:Orthopedics]]

Latest revision as of 18:48, 17 April 2024

Four Questions

Anterior and posterior fat pad signs (in a case of an undisplaced fracture of the radius head which is not visible directly).
A normal anterior fat pad in a non-fractured arm.
Anterior "Sail sign"
Normal pediatric elbow alignment
  1. Are the fat pads normal?
    • A visible ant. fat pad is normal but if displaced anteriorly (Sail sign) it is abnormal
    • A visible post. fat pad is always abnormal
    • What if have fat pad displacement but no fracture or displacement is identified?
      • Adults: Treat as radial head fracture
      • Peds: Be certain that neither an undisplaced supracondylar fracture nor a displaced internal epicondyle fracture is overlooked!
  2. Is the radiocapitellar line normal?
    • A line drawn along the longitudinal axis of the radial head and neck should pass through the capitellum
    • Whenever there is a fracture of the ulnar shaft must evaluate the radiocapitellar line for possible radial head dislocation (Monteggia fracture-dislocation)
    • This rule is always valid on a true lateral film
      • In pediatric cases the AP view may be misleading
  3. Is the anterior humeral line normal?
    • A line drawn along the ant cortex of the humerus will have at least 1/3 of the capitellum anterior to it
  4. Are the ossification centers normal (pediatric patients only)?
    • CRITOE (Capitellum, Radial head, Internal epicondyle, Trochlea, Olecranon, Lateral Epicondyle)
      • Dislocated elbow may result in avulsion of internal epicondyle
        • Because the trochlea ossifies after the internal epicondyle if you see the trochlea you must find the epicondyle!

Elbow Ossification by Age (CRITOE)

Ossification Center Age of Appearance (add 1yr for boys)
Capitellum 1yr
Radial head 3yr
Internal epicondyle 5yr
Trochlea 7yr
Olecranon 9yr
External epicondyle 11yr

CRITOE.jpg

See Also

References

  • Accident and Emergency Radiology