AMPUTATION IMMEDIATELY BELOW THE KNEE _at the_ "_true seat of election_."--The principles on which this operation is founded are--1. That a muscular flap is not necessary, skin being perfectly sufficient; 2. That as the muscles retract they must be cut at a lower level than the bones, and as they retract unequally from their varying length, the cuts must be made with due reference to that inequality; 3. That no more of the tibia need be retained than what is just sufficient to retain the attachment of the ligamentum patellæ, and to insure its vitality; 4. That the head of the fibula must be retained in every case, as in a certain proportion the tibio-fibular articulation communicates with the knee-joint. _Operation._--Two equal semilunar flaps of skin must be cut--from the outside, not by transfixion,--one anterior and external, the other posterior and internal, their extremities meeting at points about two inches below the tuberosity of the tibia on either side (Plate I. figs. 17, 18). These must be reflected up, and with them a further extent of skin, embracing the whole circumference of the limb, must be dissected up (as if pulling off the fingers of a glove), so as to expose the bone one inch below the tuberosity. The anterior muscles being very close to their origin, and consequently being able to retract very slightly, must be cut as high as exposed, and the posterior ones about the middle of their exposed surface. The bones must then be sawn as high as exposed, with the following precautions:--1. In order to prevent splintering of the fibula, endeavour to saw it along with the tibia, so as to finish it first; 2. To prevent projection of a sharp prominence of the edge of the tibia, enter the saw obliquely a little higher up than where you intend to divide the bone, then withdraw it, and enter the saw again at right angles to the bone, and a line or two lower down. Some surgeons prefer to make this section afterwards with a finer saw or the bone-pliers. This operation is very frequently required to remedy painful and unhealed stumps, the result of amputations lower down, specially those in which the long posterior flap from the muscles of the calf has been used. In the above amputation the patient will not be able to rest the weight of his body on the _face_ of the stump, but by putting the limb into a well-padded case with soft rounded edges, the weight might be borne partly on the sides of the stump, and partly on the lower edge of the patella; and the patient will be able to walk with great comfort, preserving the use of his knee-joint. AMPUTATION AT THE KNEE-JOINT.--This "relic of ancient surgery," as Mr. Skey calls it, has been revived only of late years, and seems in certain cases to be a justifiable and successful operation.