Welcome to FlyerTalk!
I'll second HiltonP's comments - I really don't think people are paying that much attention. If they hear a noise and look around, they'll see you're taking off your leg.
As a wheelchair athlete who trains and competes with amputee athletes, I see guys taking legs and arms off all the time, switching appliances, etc...it won't kill the clueless able-bodied public to get a little tuned in to the fact that not everybody's the same.