Common indications for supracondylar amputation are trauma, interference with blood supply, tumor, infections that are dangerous to life, the need for increased function, and so forth. Amputation should not be performed unless all conservative measures have failed.
The amputation at the thigh is described in detail. This is a frequent site following failure of reconstructive or bypass arterial procedures or in the presence of unreconstructable circumstances as documented with proximal and distal arteriography.
The preoperative preparation must of necessity vary with the indications for amputation as outlined in the preceding section. Careful evaluation must be made to determine whether there is a localized arterial obstruction, and arteriography is essential. If localized obstruction is present, a proximal (e.g., an iliac stent or aortofemoral) reconstructive procedure may restore an adequate blood inflow, or a distal (e.g., femoropopliteal) bypass arterial graft may eliminate the need for amputation.
When infection is present, vigorous therapeutic measures are needed. After bacterial cultures with drug sensitivities are obtained, the appropriate antibiotic is administered. Should there be a localized skin infection at the proposed level of amputation, the procedure is delayed if improvement is possible. In the presence of an advancing infection a guillotine or open amputation is done above the level of infection, with a subsequent definitive amputation at a higher point of election.
Low spinal anesthesia is used most frequently, although inhalation anesthesia may be administered unless the patient's condition contraindicates it.
The patient is placed with the hip on the affected side out to the margin of the table to allow full abduction of the thigh by an assistant, and the calf or ankle may be elevated with several sterile towels. The hair is shaved or dipped at the operative level.
The thigh from the groin to well below the knee is shaved carefully. The foot is held in abduction while the leg from below the knee to high in the groin is cleaned with appropriate antiseptics. A sterile sheet is placed beneath the thigh. The foot and lower leg up to the knee are covered with a sterile sheet or plastic drape (Figure 1). Unless there is evidence of progressive infection, the extremity is elevated by the assistant to encourage venous drainage.