While medicine has advanced greatly over the years, it is an unfortunate fact of medicine that medicine does not cure all ills. This is certainly true in the foot, and there are times where amputations, the surgical removal of a body part, are needed to be performed.  

Because the lower extremity, (the foot and leg) is furthest from the heart and central nervous system, and because the lower extremity goes through so much stress and strain, the most common region of the body where amputations are performed is in the lower extremity. 

The most common reasons for having an amputation are complications associated with diabetes, poor circulation, severe infections and severe injuries.

Diabetes can often cause diminished circulation, diminished nerve sensation and diminished healing ability, so for this reason, complications associated with diabetes are the most frequent cause of amputations.  And the foot sees more of the devastating effects of diabetes than any other part of the body.  

Poor circulation, usually from diabetes, smoking or aging is another common cause of diabetes.  In this case, the amount of arterial circulation simply does not provide adequate nutrients to the tissues to maintain viability, and the body part either dies (gangrene), or becomes otherwise so uncomfortable or problematic that an amputation may be necessary.  

Infection, too, can require amputations.  In cases where amputation is necessary because of infection, it is usually the result of one of two things: 

1.  The patient is in very poor health and cannot fight off an infection.

2.  The organism is so strong and resistant to antibiotics that the infection cannot otherwise be controlled. 

Severe Injuries can also require amputation.  In this case, the body part is crushed or otherwise damaged to the extent that the tissues are simply unable to heal.  

It is important to note that most amputations can be avoided.  If you're a smoker, quit before it shuts down the circulation to your feet. 

If you're a diabetic, keep your sugar under tight control and see your podiatrist regularly.  Regular podiatric care can diminish the odds of diabetic foot amputations sharply.  For example, a 1999 article in the Journal of the American Podiatric Medical Association showed that  high risk Medicare patients with diabetes who received preventive podiatric medical care had 75 percent fewer lower extremity amputations than high risk Medicare patients who didn’t receive such care. 

In cases of a foot infection--see a podiatrist immediately.  Waiting does nothing but make things harder to treat.

Finally, while you can't prevent all injuries, you can wear good, protective shoes and avoid risky activities that increase the likelihood of foot trauma.