An apparatus and method for supporting upper and lower vertebral bodies, including first and second end members adapted for engagement with the vertebral bodies, and at least one elongate support member coupled between the end members to maintain an axial space between the vertebral bodies. In one aspect of the invention, each of the end members has a parametrical or horseshoe-shaped configuration extending about an open inner region and defining a lateral passage communicating with the open inner region to facilitate insertion of the apparatus or the individual end members into the intervertebral space via a posterior surgical approach. In a further aspect of the invention, a fusion member is positioned within the axial space to promote bony fusion between the upper and lower vertebral bodies.