SYNDACTYLY.
The absence of one or more of the normal clefts between the fingers or toes is a common congenital deformity, and, like most of the other inherited defects of the parts, is often transmitted by descent, and associated with other malformations.
Syndactyly presents all varieties in extent and degree. Most frequently two neighbouring digits are joined together by a web of integument involving the whole or a portion of their length, but in some instances the connecting material is much thicker, and in the most extreme cases even the bones and joints are fused, leaving nothing but a furrow to indicate the line of union. ([Fig. 17, Nos. 16 to 19.])
Treatment is rarely necessary in the case of the foot, and in the hand is practicable only when the band of union is cutaneous or cellulo-cutaneous.
If the web is composed only of a thin double fold of integument it is sufficient to divide it, provided that a return of the condition is prevented from taking place through union of the raw surfaces at the root of the web. This was formerly effected in the slighter cases by a preliminary perforation of the base of the fold, and the insertion of a piece of gold wire until a cicatricial canal has been established—as in piercing the lobule for the suspension of an ear-ring—and the same end may be gained after the division by putting a small epidermic graft upon the angle. Zeller’s flap method is, however, the best. A small triangular flap is cut from the dorsum of the hand with its base opposite the heads of the metacarpal bones, its apex at the level of the first inter-phalangeal joint. This being dissected up and reversed, the whole length of the web is divided. The apex of the flap is then brought forwards between the separated digits into the proximal end of the cleft, and fixed to the cut edge of the palmar integument.
When the membrane is very thick, and the bones are drawn close together, a more complicated proceeding is required, and the ingenious method of Didot may be employed. A longitudinal incision is carried through the whole thickness of the integument along the middle of the dorsum of one of the two united fingers, a second along the middle of the palmar aspect of the other finger, and by dissection each digit is made to furnish a rectangular flap to cover in the raw surface of its neighbour. The division of the tissue left after raising the flaps must be made with great care, in order to avoid injury to the digital nerves.
ECTRODACTYLY.
Simple congenital ectrodactyly, like the loss of a larger segment of an extremity, may arise either by intra-uterine traumatism or defective development. Amputation by an amniotic band or a coil of umbilical cord probably explains the majority of the cases, as well as the congenital constrictions sometimes found in the limbs or digits of the newborn child, but the occasional appearance of fingers or toes at the end of a congenital stump can only be accounted for on the hypothesis of a temporary suspension of development in the proximal portion of the stump, and we may assume the possibility of a like origin for the absence of the most distal portions of a member. In some instances an ectrodactyly is complicated with other developmental errors, and may be transmitted through several generations. Attention has been especially drawn to cases of this class in the last few years. Two were recorded in detail in 1886 by Dr. Fotherby[41] and the author,[42] and a third was added five years ago by Messrs. Parker and Robinson.[43] In all of these the defect was traced through three or four generations, selecting in an apparently indiscriminate way a large portion of the members of the family, whilst leaving others exempt. In some individuals all four limbs were attacked, in others the upper or lower only, but usually with a more or less perfect bilateral symmetry. In most cases the ectrodactyly was associated with deformities of the remaining digits, such as syndactyly, hypertrophy, and joint distortions; and where, as frequently happened, the middle digits were imperfectly developed and the others hypertrophied and distorted, the member assumed the appearance of the pincers of a lobster. ([Fig. 17, Nos. 11 to 14.])
In Dr. Fotherby’s and Messrs. Parker and Robinson’s cases the defects were traced through three generations, affecting sixteen out of thirty-seven descendants in the one and sixteen out of thirty-three in the other; in the author’s case the history extended to four generations, attacking twenty-four out of thirty-six children, and the divergence from the normal state tended to increase with the later scions.
As a rule, little or no treatment is called for in this condition, because habit has given the member a good deal of functional utility that surgical interference might injure or destroy; but sometimes, and more particularly in the feet, it is permissible to operate for the purpose of lessening the deformity, as in Messrs. Parker and Robinson’s case, where a plastic operation was performed with much benefit to the patient.