Mad claw-hand drama

[dukejen04]

OK- I realize there are a few threads on this (and I read them and the scrubnotes article and Wikipedia) but I'm hoping someone can tell me if I'm completely wrong based on what I've gleaned.

I watched the DIT lecture today on this and then spent some time with First-Aid and here's what I want help clarifying. I REALLY don't care about the name of these claws, just the concepts.


There are two pictures in FA of various claw hands (I'm using 2011), let's discuss.

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Picture 1: This is what FA calls "Ulnar claw hand" and attributes to a DISTAL ulnar nerve lesion that causes loss of extension of PIP/DIP in the 4th and 5th digits (ie. patient is asked to extend fingers but can't so 4th and 5th fingers are clawed over). Lack of lumbricals right?

However- in the DIT lecture the dude said this could also be a PROXIMAL median nerve injury wherein there is a loss of flexion of the 2nd and 3rd digits (ie. patient is asked to make a fist but 2nd and 3rd fingers can't close).

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Picture 2: This is what FA calls "Median nerve claw hand" and attributes to a DISTAL median nerve injury that causes loss of extension at PIP/DIP in the 2nd/3rd digits (ie. patient asked to extend fingers but can't, 2nd/3rd fingers all clawed over). Again- due to lumbrical problems.

AGAIN- DIT says this could also be a PROXIMAL ulnar nerve injury causing an inability to flex the 4th/5th digits because of loss of innervation to the flexors (ie. patient is asked to make a fist but 4th/5th digits stay extended).

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In Summary (please correct me if I'm wrong):

1) A DISTAL injury to either ulnar/median nerve will result in lumbrical issues and inability to extend associated fingers (ie. extension of MCP, flexion of DIP/PIP)

2) A PROXIMAL injury affects the flexors and there is inability to flex when patient is asked to make a fist.[/B]

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[dukejen04]

Sidenote: I'm bitter I spent 7 hours on hand anatomy today.

 

[berry15]

Don't feel bitter, these FA mistakes and confusion come with the territory. I think the source of confusion is because "Pope's Blessing" & "Claw Hand" can both be caused by two different etiologies. Dr Jenkins in DIT confused me even more on the matter but when I did some research it became clear that both FA and DIT are missing the fact that there are two ways you can get each hand distortion. I am including a link that helped me, let me know if the chart in this link helps you at all. What you've said is correct, so your hours spent aren't in vain, let me paraphrase below. Best of luck!

2 ways of getting "Pope's Blessing" :
1. Trying to straighten fingers (i.e. extension of the fingers) = DISTAL ulnar nerve lesion, so the patient cannot EXTEND the 4th & 5th digits

2. Trying to make a fist (i.e. flexion of the fingers) = Median Nerve Lesion, so the patient loses the ability of FLEXING the 2nd & 3rd digits.

2 ways of getting "Claw Hand" :
1. Trying to straighten fingers (i.e. extension of the fingers) = cannot EXTEND 2nd & 3rd digits = DISTAL median nerve lesion.

2. Trying to make a fist (i.e. flexion of the fingers) = cannot FLEX 4th & 5th digits = PROXIMAL ulnar nerve lesion

http://stepjourney.wordpress.com/2010/04/06/the-infamous-popes-blessing/

Hope this doesn't confuse you more, it's been a while since I opened that page in FA!

 

[dukejen04]

Thanks berry15! I looked at that link earlier but it actually kind of says things a little bit differently. In fact, the explanation she gives is almost contradictory to what I wrote.

In my explanation (and yours) I think we agreed that the type of claw depends on whether it is a distal or proximal issue. In the post you linked to, she seems to be lumping all of them into distal injuries and distinguishing between whether the patient is asked to make a fist or extend their fingers and explains the difference in claw hands like this. No mention of proximal injuries.

But hopefully you're right and I understand it OK. Distal- no lumbricals, fingers all clawlike. Proximal- no flexors, can't make a fist with those fingers.

 

[berry15]

I remember that link helping me in class but I'll be honest I didn't read it when I posted it just, glanced at the chart. I will give it a thorough read tonight and give my 5 cents on the matter. Yes, I think we agree and I think we've got it correct! You are right in saying the name of those distortions don't matter, they will never refer to them by a name, only by the actual disfunction in the fingers.

 

[berry15]

Distal- no lumbricals, fingers all clawlike. Proximal- no flexors, can't make a fist with those fingers. YES! Awesome!

 

[dukejen04]

Thank you SO much- I really appreciate your help 😉 I definitely feel better about things now.

 

[alternatego]

Don't feel bitter, these FA mistakes and confusion come with the territory. I think the source of confusion is because "Pope's Blessing" & "Claw Hand" can both be caused by two different etiologies. Dr Jenkins in DIT confused me even more on the matter but when I did some research it became clear that both FA and DIT are missing the fact that there are two ways you can get each hand distortion. I am including a link that helped me, let me know if the chart in this link helps you at all. What you've said is correct, so your hours spent aren't in vain, let me paraphrase below. Best of luck!

2 ways of getting "Pope's Blessing" :
1. Trying to straighten fingers (i.e. extension of the fingers) = DISTAL ulnar nerve lesion, so the patient cannot EXTEND the 4th & 5th digits

2. Trying to make a fist (i.e. flexion of the fingers) = Median Nerve Lesion, so the patient loses the ability of FLEXING the 2nd & 3rd digits.

2 ways of getting "Claw Hand" :
1. Trying to straighten fingers (i.e. extension of the fingers) = cannot EXTEND 2nd & 3rd digits = DISTAL median nerve lesion.

2. Trying to make a fist (i.e. flexion of the fingers) = cannot FLEX 4th & 5th digits = PROXIMAL ulnar nerve lesion

http://stepjourney.wordpress.com/2010/04/06/the-infamous-popes-blessing/

Hope this doesn't confuse you more, it's been a while since I opened that page in FA!

awesome 🙂

 

[Monterosso]

Thanks for starting this newer claw hand thread. I too am confused and am using the FA 2012 with the errata.

From the FA 2012 errata:

Pg 409:
(1) In the entry for radial nerve, change C5-C8 to C5-T1.
(2) In the entry for median nerve, motor deficits associated with proximal lesions
include opposition of thumb, lateral finger flexion, and wrist flexion. The motor
deficit associated with distal lesions is wrist flexion.
(3) In the last column, the entries for “claw hand” and “Pope’s blessing” have been
switched. While the two can phenotypically look like one another in certain cases,
the true “Pope’s blessing” is caused by a median nerve injury and “claw hand” is
caused by an ulnar nerve injury.

Pg 410:
While “Pope’s blessing” and “claw hand” can phenotypically look like one another in
certain cases, the true “Pope’s blessing” is caused by a median nerve injury and “claw
hand” is cause by an ulnar nerve injury.

My questions are, what are the motor deficits and claws for Median lesions (proximal and distal) and Ulnar lesion (proximal and distal)? What is the pathophys for the proximal vs distal motor deficits?

 

[berry15]

Read my explanation above for the motor deficits, I am pretty sure what I wrote is correct. Forget all of the "pope's blessing" and "claw hand" mumbo jumbo, these are just names that will never come up on exams. They will most likely ask you the deficit and expect you to know where the lesion is and how it presents as opposed to those names which are ill defined in both FA and DIT. The key here is to remember the following clues:

Distal lesion = no lumbricals, clawlike fingers, cannot extend
Proximal lesion = no flexers, can't make a fist
Ulnar affects 4th and 5th fingers
Median affects 2nd and 3rd fingers

Hope this helps!

 

[Monterosso]

Thanks for the reply. Pope's hand and other names aside, I find FA 2012's entry on the deficits not so clear. Here is what they have written for the deficits (incorporating errata corrections from my earlier post):

Pg 409
1) Median - Proximal Lesion (i.e. fracture of supracondylar humerus): Motor deficits with (i.e unable to) opposition of thumb, lateral finger flexion, and wrist flexion.
2) Median - Distal Lesion (i.e. carpal tunnel syndrome; dislocated lunate): Motor deficit with wrist flexion

3) Ulnar - Proximal Lesion (i.e. fracture of medial epicondyle of humerus; "funny bone"): Motor deficit with medial finger flexion and wrist flexion
4) Ulnar - Distal Lesion (i.e. fracture of hook of hamate (falling onto outstretched hand): Motor deficit with abduction of fingers (interossei), adduction of thumb, extension of 4th and 5th fingers (lumbricals)

Does this match the 'clues' from the post above? This does not seem to be the best written entry in FA. I feel 1), 3), and 4) match the clues, however does 2)? There seems to be no mention of loss of finger extension for 3).

 

[Morsetlis]

We should just agree that "claw hand" is the worst description of a hand, ever.

 

[violinmasterdog]

Dukejen04- I'm not adding anything to the discussion, but I just wanted to say thanks! You spending 7 hrs a year ago prevented me from doing the same. Thanks!