Left-dislocation

Left-dislocation is a construction akin to topicalization. Contrary to what the name might suggest, no overt movement is involved. The element which is placed in front of the sentence is associated with some kind of pronoun:

(i) that booki, I don't think he has read iti

This construction is also known as a Hanging Topic Left Dislocation.

Link
Utrecht Lexicon of Linguistics