A height-adjustable spinal implant has first and second components that
are rotationally fixed relative to one another and axially movable along
a central longitudinal axis of the implant. Each of the components have
at least two wall segments that are fixed on a base and that extend in
the direction of the central longitudinal axis and are at a radial
distance from the latter. Circumferentially adjacent wall segments each
flank a space in which a wall segment of the respective other component
extends and is axially guided. A drive element is disposed in the
interior of the implant that engages with the second component in a
meshing relationship. The drive element bears, in the load direction, on
the first component and has a toothed ring that is used for its rotary
actuation. For the rotary actuation of the drive element, an access
opening is present in a wall segment of the first component. The free
ends of the wall segments of the first component are connected to each
other by a holding element.