How can dislocated knee cause amputation?

Here are some...: Organ or tissue removal should be the last resort of medical care after no hope to survive and to restore its presumptive function. So, dislocated knee alone should not lead to amputation unless the circulation to lower extremity is deprived enough to render the local tissue nonviable and irreversalble to restore its designated function. So, ask the treating doc for definite individual specifics.