Surgical interference is more urgently indicated in symlactylism, but not alone for cosmetic reasons. The growth of the webbed fingers is considerably affected, especially when several are grown together. 'Inc degree of deformity varies from a thin web formation between the fingers to a broad fibrous and sometimes bony connection of the phalanges. The skin passes over the webbed fingers without a groove in the most severe types and even the finger-nails do not appear to be separated.
The main object of the treatment is the separation of the connected parts. The greatest difficulty is in covering the separated surfaces with skin because of the tendency of the point of adhesion to press itself forward without the formation of a natural commissure. The intro duction of sutures and the gradual tying off of the connecting tissue is often followed by regrowth of tissue from the point of connection. Plas tic flap operations are performed to overcome this annoying complica tion. Alternate flaps are made from the dorsal portion of one finger and the ventral portion of the other so that the separated surfaces will be covered. Zeller sought. to protect the point of commissure with a small dorsal skin flap the length of the first phalanx, the dissection of which was made so that the base was at the commissure and apex at the level of the first int erphalangeal joint, and the flap was finally sutured towards the viola manus.
Great difficulties are encountered in all such operations on account of the small space and deficient skin material.
One finger generally remains uncovered and the subsequent cica tricial contractions impede the freedom of action.
The author uses a small instrument to keep the fingers apart. Two movable metal bars of triangular shape (Fig. 45e) are placed so that their edges exert a dorsoventral pressure on the tissues which are to be separated. They are very slowly approximated, one rotation or even
less of the thumbscrew daily until a groove graduaily forms which later changes into a web. The separation is accomplished when the instru ment falls out. Small sores, the result of pressure, can easily be pre vented and will heal without much trouble from cicatrices. A cor rection can be made later with the aid of Zeller's plaster flap operation should any adhesions occur. The results of this procedure are good and the treatment simple and easily carried out, even in out-patient practice, which is important with young infants.
In oligodaetylia several or even all the fingers are absent. There may be a defect in the radius with a missing thumb or a defective ulna, with the little finger absent.
Such deformities are often associated with webbing of the existing fingers (cleft hand, forceps hand).
Operative measures vary according to the conditions present.
Inclination of the fingers towards each other is caused by different pathological variations. A change in the direction of the axis of the fingers has been occasionally observed (elinodactylia).
The thumb displays many variations. Formed in duplicate each thumb may be attached to its own metacarpus or both may articulate with one metacarpus.
The thumbs may be webbed or stand in opposition to each other like the blades of a pair of forceps (pollen varus).
Thumbs with three joints are occasionally found.
Congenital differences in the size of fingers are reported as well as a giant growth of a single finger or certain parts of them. There are a thousand differences and combinations which may be manifest in the final development of an organ when for some reason or other such develop ment deviates from its natural course (macrodaetylia, braehydactylia).