For most patients requiring an amputation, the ideal location is to go below the knee. If the amputation is any further down, there would be no way to attach a prosthetic. Sometimes, there is concern about healing and the amputation has to be above the knee. Above the knee amputations are more difficult to walk with, which is why it is best to stay below the knee whenever possible.
However, below the knee amputations are not without risk. See the statistics below:
30 day mortality rate: 7%
1 year mortality rate: 20-35%
5 year mortality rate: 40-80%
Prosthetic usage rate: 48%
Rate of amputation on the opposite leg (within 5 years): 68%
Permanent institutionalization rate: 25%