Note.—Some difficulty is often felt in making the dorsal incision so as exactly and at once to hit the joint; the most common mistake being, that the transverse incision is made too high, and the knife, instead of striking the joint, only saws fruitlessly at the neck of the bone above. To avoid this, the surgeon should take as a guide to the joint, not the well-marked and tempting-looking dorsal fold in the skin, but the palmar one, which exactly corresponds with the joint between the proximal and middle phalanges, and is only about a line above the distal articulation.—(Fig. ii.)
2. Making the long flap by transfixion, it may be held back by an assistant, and the joint cut into.
Amputation through the second phalanx.—If the distal phalanx be so much crushed that a flap cannot be obtained, two short semilunar lateral flaps may be dissected (Fig. i. 2) from the sides of the second phalanx, which may then be divided by the bone-pliers at the spot required.
In cases of injury which do not admit of either of the preceding operations, it is quite possible to amputate either at the first joint, or even through the proximal phalanx. Patients are sometimes anxious for such operations in preference to amputation of the whole finger. The surgeon should, however, never amputate through a finger higher up than the distal end of the second phalanx, unless absolutely compelled by the patient, for the resulting stump, being no longer commanded by the tendons, will prove merely an incumbrance, and may possibly require a secondary operation at no distant date for its removal.
This rule is applicable in cases in which a single finger is injured, and two or three complete ones are left; in cases where all the fingers have been mutilated every morsel should be left, and may be of use.
Amputation of a whole finger.—(Fig. i. 3)—This is an operation of great importance, from its frequency.
If the third or fourth digits require amputation, it should be performed as follows:—The vessels of the arm being commanded, an assistant holds the hand, separating the fingers at each side of the one to be removed. The surgeon holding the finger to be removed, enters the point of a long straight bistoury exactly (some authorities say half an inch) above the metacarpo-phalangeal joint, and cuts from the prominence of the knuckle right into the angle of the web, then, turning inwards there, cuts obliquely into the palm to a point nearly opposite the one at which he set out.
Note.—While most authorities agree with the direction in the text regarding the palmar termination of the incision, I believe, in most cases, it is not necessary to go so far, and that the incisions may fitly meet in the palm at a point midway between a point opposite to the knuckle, and the centre of the well-marked "sulcus of flexion."
He then repeats this incision on the other side, makes tense the ligaments, first at one side and then at the other, by drawing the finger to the opposite side, and cuts them. The tendons being cut, the finger is detached. The vessels being tied, one point of suture is put in on the dorsal aspect, and the fingers on each side tied together at their extremities, with a pad of lint between them.
Modification.—Lisfranc's method is too long in its minute description to give in detail. The principle is to make a semilunar flap at one side (the one opposite the operator's right hand), by cutting from without inwards, then to open the joint from this cut, and, still keeping the edge of the knife close to the head of the phalanx, cutting the other flap from within outwards. This can be very rapidly done, but the last flap is apt to be irregular and deficient, especially in those common cases, in which, after whitlow or the like, the tissues are hard and brawny, and the skin does not play freely.