- Discussion:
    - a rudimentary thumb w/ no or very little metacarpal & no or very few muscles is categorized as a floating thumb.
    - such a floating thumb may have all assoc. abnormalities & syndromes of true hypoplastic thumb and the absent thumb.

- Radiographs:

- Treatment:
    - in case of a severely hypoplastic thumb, most surgeons prefer to amputate thumb & pollicize index digit when child reaches the age of 
         about six months;
    - if a contracted thumb web space & a very small thumb are allowed to remain throughout childhood, index finger will function as thumb in adulthood;
    - in adult patients w/ well-formed habit patterns, reconstructive surgery of thumb becomes impractical and should be avoided.