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.
It is quite unnecessary to remove the head of the metacarpal, either for the sake of appearance, or to render healing more rapid, and its removal weakens the arch of the hand; where the cartilage is eroded by disease, the cartilage-covered portion can be scooped off by a gouge or removed entire by pliers, without interfering with the broad end to which the transverse ligament of the palm is attached. If required either for injury or disease, the metacarpal head may be easily removed by a single straight incision from the knuckle upwards, as far as the point at which it may be deemed necessary to saw it through, or better still, divide it with the bone-pliers. This incision should be made as a first step in the first incision for amputation of the finger, and the finger should not be disarticulated, but kept on, to aid by its leverage in separating the metacarpal head.
Amputation of the index or little fingers.—This operation differs from the preceding only in this, that care must be taken to make a good large flap on the free side of each; making the incision, which begins at the knuckle (Fig. i. 4), enclose a well-rounded flap, and not allowing it to enter the palm till it reaches the level of the web between the fingers. The metacarpal heads may here be cut obliquely with the bone-pliers, to prevent undue projection.
Amputation of one or more metacarpals.—These operations may be rendered necessary by disease or injury. If the latter demands their performance, no rules can be given for incisions or flaps, they must just be obtained where and how they can best be got. If for disease, a single dorsal incision (Fig. i. 5) over the bone will allow it to be dissected out of the hand.
N.B.—In no case, except that of the thumb, should any attempt be made to save a finger while its metacarpal is removed. (See Excisions of Bones.)
Amputation of first and fifth metacarpals.—Various special operations have been devised for speedy and elegant removal of these bones. Their disadvantages, etc., are fully detailed under Amputations of the Foot.
The vascularity and consequent vitality of the tissues of the hand and arm sometimes afford very encouraging and satisfactory results in conservative operations.
The following is an instance of what may be accomplished in a young healthy subject.
A. A., æt. 18, ploughman, was harnessing a vicious horse, when it caught his right hand between its teeth, and gave a severe bite. On admission, I found the middle and ring fingers completely separated at the metacarpal joints, but each hanging on by a portion of skin, the middle by the skin on its radial side, the ring by that on its ulnar. The back and the palm were both stripped of skin up to the middle of the third and fourth metacarpal bones, which were exposed, but not fractured. As it was important for him to maintain the transverse arch of the hand intact, I determined to make an attempt to save the metacarpals, and finding that the skin on the radial side of the middle, and ulnar side of the ring fingers, was still warm, and apparently alive, I carefully dissected as long a flap as possible from each, and then folded them down, one at the front, the other at the back of the hand. The flaps survived, and the result was admirable, the patient being able in a very few weeks to guide the plough. The sensation in his new palm and back of the hand is very peculiar, they being still the fingers, so far as nervous supply is concerned.
In amputations involving the metacarpals for injury, it is always important to avoid entering the carpo-metacarpal joint, hence if it can be done it is best to saw through the bones at the required level, rather than disarticulate. This rule should be observed even in those cases in which the thumb alone can be saved, for notwithstanding the isolation of the joint between the first metacarpal and the trapezium, it is very important for the future use of this one digit that the motions both of the wrist and carpal joints should be preserved entire.
No exact rules can be given for the performance of these operations, as the size and positions of the flaps must be determined by the nature of the accident and the amount of skin left uninjured.
In the rare condition where the greater part of the metacarpus is destroyed, and yet carpal joints are uninjured, a most useful artificial band, preserving the movements of the wrist, may be fitted on; and as much as possible should be saved, but in cases of injury, where the carpus is opened and the hand irreparably destroyed, the question arises, Where ought amputation to be performed? To this we answer that there appears no conceivable advantage to be gained by leaving all or any of the carpal bones. If successful, it would result only in the retention of a flapping joint, unless from there being no tendons to act upon it, except the tendon of the flexor carpi ulnaris attached to the pisiform, and there are several risks it would run in the inflammation of all the carpal joints, and the almost certain spread of this inflammation to the bursa underneath the flexor tendons, beyond the annular ligament, and up the arm among the muscles.
Amputation at the Wrist-Joint.—This is an operation by no means frequent, and it has the advantages of preserving a long stump, and retaining the full movements of pronation and supination, in cases where the radio-ulnar joint is sound and uninjured, but in practice it is often found that fibrous adhesions limit to a great extent the motions of the two bones on each other, specially in those cases where the radio-ulnar joint has been diseased or injured.
Another advantage is the extreme ease with which disarticulation may be performed on emergency, no saw being required, and the ordinary bistoury of the pocket-case being quite sufficient for cutting the flaps.
Operation.—By double flap. An incision (Plate IV. fig. 3) on the dorsal surface, extending in a semilunar direction from one styloid process to the other, will define a flap of skin only, which must be raised; the joint must then be opened by a transverse incision, and a long semilunar flap of skin and fascia should be shaped (Plate IV. fig. 4) from the palm. Disarticulation is facilitated by the surgeon forcibly bending the wrist when he makes the transverse cut, and it will