A spine implant for a TLIF surgical procedure is configured to be guided into place during implantation in conjunction with a complementary insertion instrument. The cage of the implant is constrained to a limited range of rotation about a pivoting post carried by the cage. The insertion instrument is configured to hold the post while controllably rotating the cage relative to the post in order to angularly position the implant during implantation. Range of rotational motion is controlled by the configuration of an opening in and end of the cage and a groove in the pivot post. A retaining pin of the implant extends from the cage into the groove of the post to rotationally connect the cage to the post.