The word "what" is an interrogative -- asks a question -- pronoun. In the normal word order, it is, of course, "What was it?" When the sentence is turned around, it is just "bad grammar," and it still takes an interrog.
...What was it? A fracture?
...It was what? A fracture?
...What was it? A Toyota?
...It was a what? A Toyota?
...What are you referring to?
...You are referring to what?
Happy punctuating!
Margie