Digits, fingers and thumb

The draft naming convention has been developed at 8. Naming convention for anatomy  Both digit and finger/toe are used for descriptions. We would like to know if a consensus can be reached for the classification of fingers whether it includes the thumb. 

Some 'missing' concepts have been submitted and addressed for the July 2018 release. Please submit any other requests via the CRS for inclusion in SNOMED CT.

Yongsheng, I think the proposed naming conventions look good. (It might be worth considering allowing the 'x finger' synonyms to help with searching but I don't mind. (Similarly, there's other synomyms viable for the toes, e.g. hallux)

This doesn't entirely address Elze's problem though.. I'm not sure if 'fingers' should include thumb, but I suspect not - given the proposed naming conventions there's clearly a perceived ambiguity. I say "digit" is better than finger, if the specific digit isn't specified. I would say there's limited value in having both "procedure on finger" AND "procedure on digit" concepts. The fact this discussion exists hints at ambiguity...

Matt Cordell, many thanks for the feedback. The key issue is whether finger should include thumb or not. The interpretation could be different for different countries or regions. I agree that 'digit' is preferred when the specific digit is not specified to avoid potential ambiguity.

Thanks for the feedback! In the anatomy I can understand the need for a grouper concept for the fingers. Also in the Netherlands the opinion will differ if the thumb can be called a finger or not. For translation we solved this by translating 'finger' with 'finger excluding thumb', so for everyone its clear whats meant here. But by making this distinction between thumb, finger and digit, for consistency, all anatomy concepts with finger should have a variant with thumb (except for the middle phalanx). Its hard to maintain this. Especially when the anatomy is used for the modeling of procedures/disorders/findings.

For the disorder/procedure concepts Matt has a point. I think there you should avoid to use finger or at least model the correct finding site. A procedure is performed on a digit, or a part of a digit. When a procedure is performed on the middle phalanx of a digit, I think its clear that this will not be the thumb. Everytime we have to translate a concept with 'finger' we should check whether the thumb is included or not and request a concept when there is no thumb concept. Or request a change to digit.

For example 

71358006 |FInger missing (disorder)|

448901001 |Excision of ganglion cyst of finger (procedure)|

The finding site is finger structure, so apparantly you're not able to miss a thumb or to remove a ganglion cyst of thumb, because 'thumb missing' and 'Excision of ganglion cyst of thumb' is not a concept.

So the biggest problem is the inconsistency in the procedure/finding/disorder hierarchy where often finger is used where digit is (might be) meant. This problem arises because of the distinction in the anatomy that is often not used in the modeling of procedures/disorders/findings.

I think alot of procedures/findings/disorders about fingers are used to register procedures/findings/disorders of the thumb. Technically this not correct, but I'm wondering how other countries deal with this, For us, it doesnt make translation more easy. We can ofcourse close our eyes and just translate with 'finger', but it doesnt feel right 

Hi,

I'm sorry to join the discussion at this late moment...

In Canada we used the Terminologia Anatomica (TA) for translating the anatomical body structures and here what it says related to hand, digits, fingers and thumbs:

• Official Latin term: Digiti manus 
• English equivalent: Digits of hand 
• English synonym: Fingers including thumb 
  

 Note the use of "including" rather than "and".  Because of ambiguity in everyday English, they chose to use "Fingers including thumb" rather than simply "Fingers" as a synonym of "Digits of hand".  

Your proposed convention aligns with the TA. We like it!

I have asked one of our doctors and in Denmark we have the same understanding as Linda describes. /Camilla

http://www.unifr.ch/ifaa/Public/EntryPage/TA98%20Tree/Entity%20TA98%20EN/01.1.00.030%20Entity%20TA98%20EN.htm 

Thanks for the feedback Linda and Camilla. How do you translate 'finger structure'? And how do you interpret/translate the disorders/procedures with 'finger'?

In Swedish (according to the "official" Swedish dictionary published by the same not-as-scrupulous-as-it-should-be academy the names the Nobel prize in literature...) the thumb is one of five fingers, although the Swedish translation of MeSH uses the same "four or five" ambiguity as the original. (This is different from how "finger" is defined in SNOMED CT, hence the issue)

If this translates accordingly to all procedures and findings defined by 125685002 | Digit of hand structure (body structure) | or 7569003 | Finger structure (body structure) | is another question. Does anyone have a use case for a "finger, not thumb" concept?

Interestingly I asked my 18 year old daughter "is a thumb a finger" and emphatically she said "yes of course - we have ten fingers, not eight!".  But not everyone will answer the same way, not to mention the phrase "all fingers and thumbs" - we are all confused!!

Although according to the FMA as a medical class fingers include thumbs http://xiphoid.biostr.washington.edu/fma/fmabrowser-hierarchy.html?search=Finger&entryPoint=none&extendHierarchy=true (thanks to Jeremy Rogers for the reference)  However in the clinical community (and not sure how consistent this is for example with thoughts of the orthopaedic community without asking them) common usage is most often thumbs are digits but not fingers.  Jeremy Rogers made an interesting point that this is probably because:

• As digits go, both thumbs and great toes are anatomically distinct from all 16 other upper and lower digits by virtue of each having only two, not three phalanges and by having distal phalanges wider than the proximal.
• For thumbs there is the additional and critical functional difference: they're opposable, because of the specialised anatomy of the 1st carpometacarpal joint.  That's why the assessment and significance and management of lesions of thumbs is very different from the other 18 digits. 

So the current separation of body structures with thumb distinct from finger works in this instance and useful to have the separation follow through to the procedure and findings hierarchies.  Consistency in SNOMED is key to easing the process of translation as Elze mentions.  Also we have the content below which isn't helpful.

41755001 | Burn of two OR more fingers including thumb (disorder) modelled with 125685002 | Digit of hand structure.  But 42879007 | Burn erythema of two OR more fingers including thumb (disorder) is modelled only with 59354007 | Skin structure of thumb

As to not using the word "finger" at all,  it would not be reasonable in the real world for a search on "finger" to return nothing.