An amputation is the physical removal of a part of the body, most commonly a limb such as an arm or leg. Amputations are performed due to medical reasons. Medical reasons for amputation can include:
-A serious trauma injury to your limb, such as a crush or blast wound
-The limb is deformed and has limited function
-The limb being affected by gangrene, a condition sometimes occurring after peripheral arterial disease
-A severe infection to the limb. http://typeanything.com/389-phantom-limb-syndrome-following-amputation