Peeta's leg amputation was crucial in the books but ignored in the movies, changing his character's trajectory. The Mellark ... Fire, Mockingjay – Part 1, and Mockingjay – Part 2.
After young Katniss Everdeen agrees to be the symbol of rebellion, the Mockingjay, she tries to return Peeta to his normal state, tries to get to the Capitol, and tries to deal with the battles ...