I personally much prefer the terminator ideology.
As much as I'm a sucker for time traveling movies, I'm not really a fan of stuff changing in the future based on actions you take in the past, or people disappearing. I mostly like the parallel universe theory/explanation to everything.
So in this case. The world you lost your leg in will continue on with you out of it. You are then in a parallel universe stuck with another you who avoids losing their leg, and life goes on.
I am the black sheep "of course I'm crazy, but that doesn't mean I'm wrong."-Robert Anton Wilson