Amputation refers to the surgical or traumatic removal of the terminal portion of the upper or lower extremity.

Perform surgical amputations to:

Determine the amputation level by the quality of tissue and by the requirements for prosthetic fitting. The standard levels for lower extremity amputations are shown in Figure 18.75. In the upper extremity, preserve as much limb length as possible.

Figure 18.75

Evaluation

Techniques

Guillotine amputation

Use a guillotine amputation in emergency situations for contaminated wounds or infection as a quick means of removing diseased or damaged tissue.

1	Divide the skin, muscle and bone at or near the same level, without attempting to fashion flaps or close the wound (Figure 18.76).
Figure 18.76
2	Tie all bleeding vessels and cut the nerves sharply while under gentle tension, allowing them to retract into the wound. Tack skin flaps loosely with a few stitches to prevent further retraction. Apply a sterile dressing and, if possible, an elastic stump wrap.
3	Debride and lavage the wound every 2–5 days until it is free of dead tissue and infection. At that point, perform a definitive amputation and closure.

Definitive amputation

Perform a definitive amputation as an elective procedure when the extremity is clean and non-infected or following a guillotine amputation.

In the upper limb, preserve as much of the limb as possible. The ideal levels for a lower extremity amputation are 12 cm proximal to the knee joint (transfemoral) and 8–14 cm distal to the knee joint (transtibial). When possible, save the knee joint to improve function with a prosthesis. Amputations through the knee are acceptable in children.

1	Cut the skin flaps 5–6 cm, and the muscles 2–4 cm, distal to the proposed level of bone section (Figure 18.77).
Figure 18.77
2	Fashion the skin flaps so that the sum of the lengths of the flaps is one and a half times the diameter of the limb. Local conditions may necessitate unequal or irregular flaps.
3	Taper the anterior end of the bone and cut the fibula 3 cm proximal to the tibial cut.
4	Doubly ligate all major vessels (Figure 18.78).
Figure 18.78
5	Cut the nerves sharply while under gentle tension and allow them to retract into the wound. Stitch opposing muscles over the end of the bone and attach the muscle flaps to the bone through the periosteum or a drill hole.
6	Release the tourniquet and stop all bleeding before closing further.
7	Suture the skin and fascia loosely in two layers, using interrupted stitches. If skin closure is a problem, use split thick skin grafts on non-weight bearing portions of the stump. Do not close the skin under tension.
8	In most cases, use a drain and plan to remove it in 1–2 days. Apply a firm bandage and place the remaining limb in a plaster splint.
9	Make the stump cylindrical with even muscle distribution. A conical or bulbous stump will be painful and difficult to fit to the prosthetic socket.

Foot amputations

Perform amputations within the foot at the base of the toes or through the metatarsals, depending on the level of viable tissue. Amputations more proximal on the foot (tarsometatarsal joint or midtarsal joint) are acceptable, but may lead to muscle imbalance. They may require splinting and tendon transfers in order to maintain a plantagrade foot for walking.

Upper extremity amputations

Amputations in children

Children adapt more easily than adults to amputations and prosthetic use. When possible, preserve the growth plate and the epiphysis to allow normal growth of the extremity. Trans-articular amputations are well tolerated, as is the use of split thickness skin grafts on the weight-bearing surface of the limb.