amputation

amputation The word ‘amputation’ derives from the Latin ambi — around — and putare — to prune or lop. The word can be applied to the removal of any part of the body, but it is usually restricted to removal of part of a limb, unless the word is qualified, as in ‘amputation of the nose’. Children born with an absent part of a limb are often said to have a congenital amputation.

The amputation of a limb represents one of the earliest forms of surgery and was performed for severely damaged arms and legs in both war and peace over many centuries. In the days before anaesthesia, speed was of the essence; the surgeon would cut through the flesh of the limb with a single sweep of the knife and then divide the bone with a few strokes of the saw. Haemorrhage was dealt with by the crude technique of cauterization of the stump, using boiling oil or a red-hot iron, until Ambroise Paré (1510–90), a French military surgeon, showed that tying of the blood vessels was a far safer and much kinder method. In modern surgical amputations, skin flaps are raised, the soft tissues carefully divided, blood vessels tied, the bone divided, the soft tissues and then skin carefully sutured, and the stump bandaged to produce a relatively aesthetic appearance.

The indications for amputation of a limb include severe injury, where the blood supply to the limb has been hopelessly damaged; severe infection following injury (particularly gas gangrene); malignant tumours of bone or of the adjacent soft tissues; and occasionally the removal of a hopelessly deformed arm or leg. In peacetime, however, by far the commonest indication is gangrene due to severe arterial disease, usually arteriosclerotic or diabetic in origin, and not infrequently from a combination of these two conditions.

With modern surgical techniques, the limb that was once doomed to amputation can often be saved. Whereas at one time damage to the main limb artery in a fracture or a missile injury usually meant loss of the arm or leg, reconstructive arterial surgery can now often repair the damaged vessel, often by means of an interposed graft of a vein taken from the superficial tissues of the leg. For example, surgeons in Northern Ireland have become experts at reconstruction of the popliteal vessels behind the knee destroyed in terrorist ‘knee capping’ punishments with salvage of the leg in almost every case.

Severe arterial disease of the leg arteries is common and once inevitably led to amputation. Fortunately, this again may be overcome by a bypass of the obstructed segment of the artery, using the patient's own vein or a synthetic graft. In other cases, the diseased artery can be opened and cored out, in the operation of endarterectomy. Alternatively, the narrowed, stenosed segment can be dilated by a catheter which carries an inflatable balloon, inserted above the segment and guided to it under X-ray.

Limbs that once had to be removed due to a tumour can now sometimes be preserved by removing the bone growth itself and replac-ing the missing segment by means of a metal prosthesis.

When amputation is necessary, rehabilitation of the amputee is an important adjunct to management. The crude artificial limbs of the past — the amputee kneeling on a peg leg, or a purely cosmetic and non-functional upper limb prosthesis — have now been replaced by very sophisticated devices. For lower limb amputees lightweight limbs with ingenious ‘joints’ allow a below-knee amputee to walk normally, and even engage in various exercises, such as running in Olympic-style events. Above-knee prostheses are more of a problem, but a ‘knee joint’ with a locking device enables efficient walking to be carried out. An upper limb prosthesis may be fitted with pulleys activated by the shoulder girdle muscles, which enable activation of an artificial gripping ‘hand’ and a functioning ‘elbow’. These devices, ingenious though they are, can only be made to be effective if used by an enthusiastic and motivated patient trained by a dedicated team of orthopaedic surgeons, physiotherapists, and limb makers; these are combined in the modern speciality of orthotics.

Harold Ellis

See also phantom limb; prostheses.