Under what circumstances would amputation of a limb be needed?

Question

Please list as many as you can.

Answer 1

Necrosis (gangrenous), compartment syndrome (too late for fasciotomy), any cause of extended vascular compromise, catastrophic injury... pretty much any combination of vascular deficiency and/or superimposed infection (particularly in the context of Diabetes Mellitus).

Obviously, from the vantage point of Orthopaedic Onc., primary osseous or soft tissue malignancy, e.g. osteosarc. NOS, Ewings, etc.  The list goes on and on.