User blog comment:Gourgeist/Shingeki no Kyojin Chapter 65 Review: Dreams and Curses/@comment-7418318-20150112232657/@comment-110.175.182.16-20150117055727

Eren has grown back entire limbs, so I think he would be able to regrow parts of his spine (as long as getting part of his spine removed doesn't kill him. So everyone lives happily ever after.