13 More Major Retcons In The Marvel Cinematic Universe

4. Tony Stark Actually WAS Curable

In Iron Man, it's pretty firmly confirmed that Tony Stark has to have an arc reactor fitted into his chest because without it he would die. The shrapnel pieces working their way towards his heart are so terrifyingly fatal that sticking a huge electro-magnet initially powered by a poisonous element into his actual sternum is the ONLY way to stop certain death.

If there was any other option, wouldn't he have considered it when the Palladium in the reactor was literally killing him in Iron Man 2?

Seemingly, Tony just didn't do his research properly, because in Iron Man 3, it turned out that all he needed was a really skilled surgeon. Because right at the end of that movie, the finality of his injuries are forgotten as one procedure removes the shrapnel and he remains alive.