Disclosed is an apparatus for forming an arcuate channel in one or more segments of a bone, bony structure or adjacent vertebrae of a spine. The apparatus includes, inter alia, a base member which is positioned proximate to the surgical site, a support arm extending proximally from the base member, an arcuate guide member and a drill assembly. The arcuate guide member is slidably mounted to the support arm. The drill assembly is operatively coupled to the support arm and includes a drill bit attached to the distal end of a flexible drive cable. The flexible drive cable extends axially along the support arm and is axially and rotationally movable with respect thereto. The drill bit is operatively coupled to an end of the arcuate guide member such that when the drill assembly is moved distally, the arcuate guide member slides with respect to the support arm and forces the drill bit to traverse an arcuate path.