Below-Knee Amputation Surgery

Throughout the history of lower-extremity amputation surgery, the relative emphasis placed on various parts of the procedure has undergone many changes as new techniques have become available and as new goals have been appreciated. At present, the amount and direction of available knowledge demand the surgeon's concern with fundamental principles. Since some of these problems must be considered whatever level is chosen for amputation, they will be discussed before those that are peculiar to below-knee amputation. As seen in the earliest reports on amputation, from the times of Hippocrates and Galen, this drastic measure was taken for the sole purpose of saving life but, as it usually turned out, it was instead a lethal procedure owing to shock and to loss of blood. Therefore, all emphasis was placed on the speed with which the operation could be completed. Patients who survived the operation frequently died of septicemia. After hemostasis, antisepsis and asepsis, and anesthesia all came into use in the midnineteenth century, however, speed became less important, less painful and extreme surgical procedures could be developed, and surgeons began to give more attention to conservation of tissues. Another change in emphasis was prompted by technical advances in articulated prostheses (first invented in the sixteenth century). Functional aspects of the stump then became the main consideration, and together with the prosthesis they came more and more to dictate the level and type of amputation. This development is most fully illustrated by the popularity—which persists even now (P)—of the zur Verth scheme, or "site-ofelection" concept. A "functional" means of determining the optimum amputation level, this arbitrary plan was obviously never intended for use in any and all situations, such as trauma, and certainly not under conditions of mass casualties, where conservation of tissue and open drainage are essential. But it has been used in such situations and has led to unnecessary loss of valuable segments of limbs. Dederich (8) points out that a military order of the German Army Medical Corps during the last part of World War II was necessary to prohibit use of zur Verth's scheme for primary and usually septic amputations, the order directing that tissue-sparing open amputations be used. Since that time it has become increasingly clear that distinctions must be made in regard to the conditions under which the amputation is done and that the technique must be related to these distinctions. Under emergency conditions, the primary consideration of the surgeon is to treat for shock to save the life of the patient. His thought and his actions are directed toward preservation of the limb rather than toward amputation. Conservation of blood supply, restoration of nerve connections, and debridement of crushed tissue are his main concern. Large operative procedures should not be undertaken, because surgical shock cannot be added to the already existing shock. If amputation becomes a matter of life or death, the level is then not the choice of the surgeon. It is forced on him. He will try to preserve as much useful tissue as possible, but the general condition of the patient dictates the measures. It is because of these factors that even revised stumps are often not of a length that the limbfitter might consider ideal. In a recent publication (7) of the Committee on Trauma of the American College of Sur-