This is one of the very few operations in which quickness of performance is a desideratum; the use of anæsthetics has, in most other cases, given time for elaboration of flaps, and careful dissection; here the risk of loss of blood, specially from the posterior flap, renders rapid disarticulation imperative.
Amputation by double flap, anterior the longer.—In hip-joint amputations, besides the ordinary sponge-squeezers, two assistants are necessary, whose duties are exceedingly important.
The first is to check hæmorrhage. Pressing with a firm pad on the external iliac just as it passes the bone, he must be prepared, the instant the anterior flap is cut, to follow the knife and seize flap and artery in his hand, and he is to hold it there till all the vessels in the posterior flap are first tied.
The second has to manage the limb, and on the manner in which he performs his duty much of the success and nearly all the celerity of the operation depend. While the surgeon is transfixing the anterior flap, this assistant is to support the limb in a slightly flexed position, so as to relax the muscles; the instant the flap is cut he is to extend the limb forcibly, and at the same time be careful not to abduct it in the least, but to turn the toes inward so as to bring the great trochanter well forwards on a level with the joint; if this precaution is neglected, the operator in making the posterior flap is almost certain to lock his knife in the hollow between the head of the bone and the great trochanter.
If it is the left side, the operator, standing on the outside of the limb, enters the point of a long straight knife midway between the anterior superior spinous process of the ilium and the great trochanter, and passes it as close to the front of the joint as possible, making the point emerge close to the tuberosity of the ischium ([Plate IV.] fig. 20-20). With a rapid sawing movement he then cuts a long anterior flap, avoiding any pointing of it, and endeavouring to make the curve equal. The fingers of the assistant must be inserted so as to follow the knife and seize the vessel even before it is divided. The flap being raised out of the way, the surgeon, without changing his knife (as used to be advised), opens the joint, divides the ligaments as they start up on the limb being extended and adducted, the round ligament, and the posterior part of the capsule; and then getting the knife fairly behind both the head of the bone and the trochanter, cuts the posterior flap as rapidly as possible. Instantly on the limb being separated, assistants should be ready with large dry sponges or pads of dry lint to press against the surface of the posterior flap, till the large branches, chiefly of the internal iliac, which are cut in it, are tied one by one.
The lever invented by Mr. Richard Davy, by which the common iliac is compressed from the rectum, has in many cases proved of great service in preventing hæmorrhage, but has dangers of its own in cases of abnormal position of rectum, or even in sudden movements of the patient.
In every case the abdominal tourniquet will be found of great service in checking hæmorrhage, during the operation of amputation at the hip-joint. It consists of an arch of steel fitted with a pad behind, which rests against the vertebral column, and a pad in front playing on a very fine and long screw, through an opening in the arch. When screwed down tightly on the aorta just before the incisions are commenced, it checks hæmorrhage admirably without injuring the viscera. When this is applied, a method of amputation once practised by Mr. Syme, though not so rapid as the double-flap method by transfixion, will be found very easy, and to result in most excellent flaps. He cut an anterior flap in the usual manner by transfixion, then made a straight incision from its outer edge down to about two inches below the great trochanter, thus exposing it fully, and from the lower end of this incision transfixed again, cutting a posterior flap nearly equal in size to the anterior; a few strokes of the knife round the joint finished the disarticulation. The resulting flaps came together with great accuracy, and were not burdened with the great unequal masses of muscles so often noticed in the posterior flaps which are made by cutting from within outwards after disarticulation.
In some cases of amputation where the femur has been badly shattered, it is a good plan to amputate through the upper third of thigh, tie all the vessels, and then, aided by an incision at outer side, dissect out the head of the bone.
Mr. Furneaux Jordan of Birmingham carries out this principle by first dividing the soft parts in circular direction low down the thigh, and then dissecting out the head of the bone from the muscles by a long incision on the outer aspect of the limb.
Note.—In severe cases of smash when both lower limbs have required amputation, the author has derived much assistance from the method of managing the operation detailed below:—