heel's convexity. In four of the remaining cases the separation occurred one-fourth of an inch, and in the other four cases one-half an inch below this line M N (see diagram). Any variations in the point of division tend, in all cases, toward the line of incision in amputations in this region. In thirtyFig. 105.

H

Diagram showing the arterial supply to the calcaneau region, on the tibial side of the foot (drawn by the author, from the average of eighty dissections). M. Internal malleolus. PMC N. Tibio-tarsal quadrilateral, the surgical regiou of this articulation. K. Posterior tibial artery 0. Its point of bifurcation into G. Internal plantar and F. External plautar artery. III. Calcanean branches of external plantar. T Articular branches from posterior tibial. H. Articular branch from internal plantar. Q. Tendon of tibialis posticus muscle. R. Tendon of flexor longus digitorum. S. Tendon of flexor longus pollicis. MC. The line of incision of Gross. ML, MD, ME, M E'. Lines of incision showing that the nearer the incision approaches the heel, the more danger is incurred of cutting off the priucipal blood supply to the calcanean flap, in amputation. M N. Line crossing the usual point of bifurcation of the posterior-tibial. MA, M B. Anterior incision.

eight out of eighty dissections (almost one-half) there was not a single calcanean artery derived from the posterior tibial (K O, see diagram). So it must follow that any line of incision that approximates the terminal bifurcation of this vessel will, in a great many cases, endanger the blood supply, and consequently the success of the operation.. . From the standpoint of surgical anatomy, the incision recommended and practised by Prof. Gross, and represented in the above diagram by the line M C, is the most rational, since it is furthest removed from the

most constant blood supply to this inferior flap, viz., the calca nean branches of the external plantar artery."

.

Fig. 106 represents the outlines of Prof. Gross's operation; and the directions for its performance I will give in his own language: "Syme's Amputation .. is performed with two flaps, one of which is taken from the front and the other from the sole of the foot, the two meeting at the outer and inner ankle. The best instrument is a large scalpel; the foot is placed at a right angle with the leg, and the circulation is controlled by means of the tourniquet applied to the popliteal artery. The operation is commenced by making an incision perpendicular or nearly perpendicular from the centre of one malleolus to that of the other, directly across the sole of the foot, and then carrying another, of a curvilinear shape with the convexity looking forward, over the fore part of the limb, so as join the two points of the former at an angle of 45°. The lines of these cuts are well seen in Fig. 106. The anterior flap is

Fig. 106.

now carefully raised, the astragalus disarticulated, and the posterior flap dissected off from the calcaneum, by passing the

1 Am. Journ. of Med. Sci., vol. Ixxi. p. 392.

knife closely over its surfaces, as in Fig. 107, in order to avoid wounding the tibial artery. The tendo Achillis being severed from its connections, the operation is finished by sawing away the two malleoli and a thin slice of the tibia, just enough to include its cartilaginous incrustation. The posterior flap thus formed, consisting of the thick and hardened cushion of the heel, offers an admirable covering for the exposed bones, to which it usually unites by the first intention, and which afterwards enables them to bear pressure with great facility. The

only objection to it is that, unless special care is taken in its adjustment, it may form a sac for the accumulation of matter, thus greatly retarding the cure. This, however, is generally easily prevented by the proper application of the bandage in dressing the stump at and for some time after the operation. Should this contingency, however, arise, relief must be afforded by a small puncture through the plantar surface of the flap. The appearance of the stump after the parts are healed is shown in Fig. 108. In performing this operation there are three points which deserve special attention. The first is not to have a redundancy of flap, which will seldom happen if they are both

shaped in the manner here described; the second is not to cut any holes into the posterior flap while severing its connections with the calcaneum; and the last is not to divide the posterior tibial artery prior to its separation into its plantar branches, otherwise sloughing of the soft parts might ensue from deficient nourishment. If these precautions be observed, it will be difficult to make a bad stump. When the cure is completed the limb will be from an inch to an inch and a half shorter than natural. When, in consequence of disease, the flaps cannot be formed according to the plan now laid down, they may be taken from the sides of the limb, including as much of the integument of the heel as possible. The operation is easy enough of execution, but the cicatrice after the healing of the stump will be much in the way of the patient's comfort, and may lead to the necessity of amputating the limb higher up." Every step in the performance of this operation has been carefully detailed by Prof. Gross, and consequently it only remains for me to mention, in connection with the above, that, as a protective measure against the accumulation of fluid within the heel flap, in every instance a puncture should be made in its most dependent portion, and through it should be passed a drainage-tube. This precaution will frequently prevent sloughing and septic complications. The after-treatment requires no other special description.

PIROGOFF'S AMPUTATION.

Syme's operation was modified in 1852 by Mr. Pirogoff, of Russia, who retains a portion of the calcaneum, thus giving greater length and rotundity to the stump. The soft parts are incised in exactly the same manner as has been recommended for the performance of Syme's operation. The foot being placed at a right angle with the leg, the first incision should be drawn from the centre of one malleolus to the centre of the other directly across the sole of the foot; the second incision should connect with the extremity of the first at an angle about 45°,

1 System of Surgery, vol. ii. p. 1034, 1866.

and should pass over the dorsum of the foot so as to form a crescent-shaped flap. The anterior flap is now dissected up sufficiently to expose the ankle-joint which may be readily opened and the lateral ligaments divided by passing a strong knife between the astragalus and the malleoli, after which the foot can be dislocated, and the upper surface of the back of the os calcis exposed. The heel flap is dissected up sufficiently to clear the way for the saw. The limb is now steadied by an assistant while the surgeon extends the foot as much as possible,

and while it is still held in his left hand he applies a common saw to the os calcis immediately behind the astragalus, and the bone is cut obliquely downward and forward, so that the saw comes out directly behind the articulation of the os calcis with the cuboid. This part of the operation is well represented