Fractures -- Colles vs. Smith

[MedStudentWanna]

Can someone explain the differences between Colles and Smith's fractures to me? I don't see the difference on x-ray.

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[coup de chance]

WIKI is pretty good http://en.wikipedia.org/wiki/Smith's_fracture
Smith = reverse Colles' fracture is a fracture of the distal radius.[1] It is caused by a direct blow to the dorsal forearm[2] or falling onto flexed wrists, as opposed to a Colles' fracture which occurs as a result of falling onto wrists in extension. Smith's fractures are less common than Colles' fractures. The distal fracture fragment is displaced volarly (ventrally), as opposed to a Colles' fracture which the fragment is displaced dorsally. Depending on the severity of the impact, there may be one or many fragments and it may or may not involve the articular surface of the wrist joint.


My mneumonic --
Colles = dinner fork
Smith = the other way

Can someone explain the differences between Colles and Smith's fractures to me? I don't see the difference on x-ray.

http://hphy36208.pbworks.com/f/smith fracture.jpg

 

[MedStudentWanna]

Thanks but my problem is not being able to tell them apart on x-ray.

And I never really understood the dinner fork thing.

 

[coup de chance]

Thanks but my problem is not being able to tell them apart on x-ray.

And I never really understood the dinner fork thing.

Smith:

http://www.feinberg.northwestern.ed...o-teaching/wrist/case62/case62background.html

Colles:

http://img.medscape.com/pi/emed/ckb/radiology/336139-398406-7418.jpg

Dinner fork:

https://www.landfcookshop.com/shoplandf/images/dan_dinner_fork.jpg

 

[MedStudentWanna]

But what about when they're both lateral view like these? How do you differentiate?

http://tinyurl.com/2cm2zb6

http://tinyurl.com/2flget8

 

[coup de chance]

... lateral is the only kind that I can differentiate Colles v Smith.

Both the links below look like Colles = dorsal displacement of distal radius.
Correct me if wrong.

But what about when they're both lateral view like these? How do you differentiate?

http://tinyurl.com/2cm2zb6

http://tinyurl.com/2flget8

 

[MedStudentWanna]

One is supposedly Colles and one is supposedly Smith.

 

[coup de chance]

One is supposedly Colles and one is supposedly Smith.

Sorry. I totally missed the the obvious on my own post above...

WIKI says you're supposed to look at the distal fragment.

So -- distal FRAGMENT displaced volarly = Smith
dorsally = Colles

So "Bones 42 of 42" is Smith
"PR" is Colles

A minute ago, I thought "PR" was showing normal, but then I saw that the joint spaces are bigger than normal.

This is normal -- also, the alignment of hand and arm is pretty straight.

http://boneandspine.com/wp-content/uploads/2008/12/normal-wrist.jpg

Another normal

http://4.bp.blogspot.com/_m8_CWezId...MSxk8FrUo8/s400/normal_wrist_ap_lat.gif01.gif

 

[coup de chance]

Dinner forks have a dorsal bump distally (akin to the dorsal displacement of distal fracture fragment at distal radius = Colles)

I'm sure dinner fork makers use that same exact mnemonic