38 
Split-Hand and Split-Foot Deformities 
of tarsal bones and metatarsals in the cleft, but their welding together and dis- 
order often preclude an accurate description, compatible with brevity (Figs. 15, 
16, 21). It is an invariable rule that a proximal bone is never absent when 
a corresponding distal one is present. Of the metatarsals, which remain, those 
bearing terminal phalanges are usually considerably thickened while those which 
bear no phalanges show hypoplasia, which is greater peripherally. There are often 
indications that the thickening of the 1st and .5th metatarsals is due to welding 
with the remaining portions of the neighbouring metatarsals, namely the 2nd 
and 4th (cp. Figs. 8, 9, 15, 16). 
From the detailed description of the " G " family and this general description 
it will be seen that there is a good deal of variation in the feet, but at the same 
time the points of resemblance are still more striking. In short these resemblances 
are the clefting with the absence of at least all the phalanges and half the meta- 
tarsal of one toe and the absence of one or more phalanges from neighbouring toes 
(Fig. 25), the syndactyly of all the remaining toes, or parts of them, into two 
groups, the broadening of the feet and the inturning of the terminal phalanges, 
and lastly the presence of split foot on both sides. Briefly tlie variation in the 
deformity is of degree and not of kind. 
Passing to the hands, it will be remembered that they are not affected unless 
the feet are split. Also that in rare cases, one hand may be norraaP, or more 
often both normal"'". Further they may show syndactyly or Polydactyly without 
other defect of the bones (IV, 3, etc.). There may be loss of one or more phalanges 
from one finger. Finally gross deformity may be found, and this is the rule. 
This again shows great variations but two general types may be separated. In 
one the hand is split, by reason of ectrodactyly of the 3rd (middle) finger. Such 
splitting commonly extends to, but not into the carpus*; on the other hand it may 
fail to involve the metacarpal (V, 7), and in this case the corresponding phalanges 
may constitute cross-bones. In a single instance-' there has been a strong suggestion 
of division of the 3rd phalanges, the component parts lying to either side of the gap. 
As in the feet the process may be more extensive and involve the 2nd (Fig. 22) 
and 4th digits. In tfie other variety the ectrodactyly proceeds^ from the radial 
side and the bones escape according as they approximate to the ulnar side. In 
this form it is usual for the 5th (Figs. 6, 7), or 4th and 5th (Figs. 14, 18, 19) 
fingers to have a complete complement of bones. Exceptionally no finger is 
complete. In two instances the 5tii finger has shown more change than the 
4th"' "\ The 3rd metacarpal is rarely and the 2nd usually affected; frequently 
they both carry one or more phalanges, those of the outer being more complete. 
The thumb is in most instances absent or represented by a sliort bone only, but it 
may show any grade from this up to the possession of all its bones (Fig. 23). 
* Affection of the carpus has been thought probable by writers in certain cases, but no clear 
evidence of it has as yet been forthcoming. Through the kindness of Professor Pearson we have 
recently seen a case, as yet unpublished, in which it appears to occur. 
t Compare footnote on page 37. 
