An intervertebral stabilizer includes: a first plate member operable to engage an endplate of a first vertebral bone of a spine; a second plate member spaced apart from the first plate member and operable to engage an endplate of an adjacent second vertebral bone of the spine; a ball element depending from the first plate member; and a socket element depending from the second plate member, wherein at least one of the ball and socket elements include one or more keyed surfaces such that: (i) an assembly function is obtained in which the ball element may at least one of be received into, and removed from, the socket element in one or more first articulation positions of the first and second plate members; and (ii) a capture function is obtained in which the ball element may at least one of not be received into, and not be removed from, the socket element in one or more second articulation positions of the first and second plate members.