56.1 The general method for amputations

You will need to amputate a patient’s leg about five times more often than his arm. Once you have cut off a limb there is no going back, so try to retain as much function as you can. The patient is unlikely to get an arm prosthesis, and it would be of little use even if he could get one. So aim instead for the longest possible stump of an arm. Every centimetre is useful, so is an elbow which he can use as a hook, and so is any kind of a wrist.

A patient’s leg must have a prosthesis which will bear his weight. There are a limited number of these, and the stumps for hem are standardized. So always do one of the standard leg amputations. There are three technological grades of prosthesis; of these the third is not necessarily the worst. A patient might have: (1) A sophisticated modern prosthesis costing $ 300 or more. (2) A simpler modern prosthesis costing $ 30, such as one of those developed by Huckstep for polio (26.2), which any bicycle mechanic can mend. Or, (3) the patient might have a traditional prosthesis, such as a pylon, a peg leg, or elephant boot. Don’t despise these; when well made they last longer than any of the others, and are better than a modern prosthesis for working in the fields.

A leg prosthesis can: (1) Have a cup to bear weight on the sides of the stump, in which case the scar should be at the end. (2) Bear weight on the end of the stump, in which case the scar should be posterior. (3) Have a modern total contact socke in which the position of the scar is unimportant. Limb fitting centres vary in their scope and preferences, so visit your local one and find out what they like. A good prosthetist can fit any well constructed stump with a prosthesis.

IN THE ARM CONSERVE EVERY CENTIMETRE, IN THE LEG DO A STANDARD AMPUTATION

In the abdomen poor surgical craftsmenship is hidden, but on an amputation stump it is there for everyone to see. In a perfect stump: (1) The scar is not exposed to pressure. (2) The skin slides easily over the bone. (3) The skin is not infolded. (4) There is no redundant soft tissue. (5) There is no protruding spur of bone. (6) The stump is painless. And, (7) the wound has healed by first intention. Most amputation stumps should be conical.

Fish mouth flaps

As a general rule, cut the fish mouth flaps shown in Fig. 56-4. The alternative is a guillotine amputation, as described in Section 56.2. Fish mouth flaps must be long enough to cover the soft tissues of the stump, but not be so long that their blood supply is inadequate and they necrose. If the flaps are equal, the scar will come at the end of a stump. If they are unequal the scar can come at the front or the back. Try to place the scar where it is not going to be pressed on. In the hand and the foot, place it dorsally. Higher up the arm the scar can be anywhere. In the leg, its site depends on the kind of prosthesis the patient is to have—end bearing, side bearing, or total contact. In the lower arm and leg transverse scars are better than anteroposterior ones because they do not get drawn up between the two bones.

Immediate suture or delayed primary closure?

Delayed primary closure is always wise: (1) If the patient’s limb is already infected, or might easily become so. (2) In all battle casualties. (3) If there is much soft tissue injury. (4) If the blood supply of the stump is uncertain. If you decide on delayed primary closure, cut the flaps long, to allow them to retract. Leave the patient’s muscle and fascia unsutured, bandage the skin flaps over dry gauze swabs, don’t put in any stitches, and bring him back to the theatre 3 to 5 days later. If his wound is not infected, close it. If it is infected, leave the flaps open for a week or longer, and close it later by secondary suture.

Postoperative care.

Much depends on what happens to a patient after he leaves the theatre. His leg stump must be prepared for the prosthesis, and he need, to be taught how to use it. Firm bandaging will hasten to conversion of his stump from a bulky cylinder to a narrow cone, and exercises will strengthen its remaining muscles. So, give the stump something to do. After a lower leg amputation he can learn to kick a large rubber ball about.

How do amputations differ in children?

Most of the same principles apply in a child. Disarticulate a joint if you can, especially at his knee, because this will preserve its epiphysis. Removing a limb by amputating through the shaft of a bone produces an effect which varies with the site. It can either cause excessive bony overgrowth with the need for a revision amputations later, or a short stump.

• SAW, amputation, with hinged back, 230 mm, (a) saw, one only. (b) Spare blades for the above, three only. The back of the saw stiffens it during the early part of the cut, but can be hinged back later to let the saw pass through.

• SAW, Gigli, (a) pair of handles, one pair only, (b), Saw blades, 30 cm, four only A Gigli bone saw is a piece of wire with sharp teeth on it which you pull to–and–fro between two handles. Use it to cut bone in awkward places.

• KNIFE, amputation, Liston 180 mm, one only If you don’t have an amputation knife, sharpen a long kitchen knife and use that.

Here is the sequence of steps for all amputations. they are not repeated in the instructions for the specific sites described later. Follow the steps in the order in which we give them here.