Peripheral arterial disease is the leading cause of leg
amputation in the UK. When the blood supply falls below a certain
critical level, there is not enough blood and oxygen reaching the
tissues and they begin to die. The key signs of this are continuous
pain even at rest, development of ulcers or the non-healing of
minor injuries, or dry black shrivelled toes (necrosis).
Unchecked, the pain will increase and often requires morphine to
ease it, or infection may set in causing fever and systemic
illness. Either of these developments is an indication that
amputation may be required to save life or quality of life.
Investigations such as Duplex scans and angiogram will show whether
there is any possibility of improving the circulation.
An amputation can be a lifesaving operation, and many patients
will mobilise on prosthetic legs to a good quality of life. The
main concerns as far as the surgery is concerned are achieving good
healing and preserving the maximum use in the leg. Because the body
is very good at preserving blood supply until a very late stage,
many patients will present with a small ulcer on the heel or toes
but with no way of improving the circulation and they will end up
with a major amputation.
There are several types or levels of amputations, the least
being removal of one or more toes. This might be for bone infection
(osteomyelitis) or where the toe is black but the blood supply to
the main part of the foot is sufficient to allow the tissue to
heal, perhaps after an angiopasty or bypass operation. Even if all
the toes are beyond saving, so long as the heel is preserved with
healthy skin, the leg can be used to walk reasonably normally with
an amputation through the middle of the foot. Unfortunately, the
blood supply to the foot is often not much better than the toes and
is not enough to achieve healing.
If the foot cannot be saved, the next level of amputation is
through the fleshy part of the calf, below the knee. The muscles
are used to create a padded stump that lets you use a prosthetic
In severe cases, or where mobility on a prosthetic leg is never
likely, then the preferred level of amputation is through the
thigh, again, the muscles are used to cover the bone and produce a