Patent ID: 8579981

Claim:
A device to space vertebral members comprising: first and second elongated, non-annular members each with opposing first and second ends, an exterior side, and an opposing interior side, the first member including first ramped section and the second member including a second ramped member configured for insertion into the second member and configured to slidable movement within the second member, the first member further including a sidewall on the interior side positioned closer to a perimeter of the first member than the ramped section, the sidewall having a height greater than the ramped section to extend outward from the interior side beyond the ramped section; the first and second members positioned in a vertically overlapping arrangement with the interior sides facing together and the sidewall in a horizontally overlapping arrangement with second member, such that the first and second members form a device length; the device being positionable between a first orientation with the ramped section of the first member positioned away from the ramped section of the second member, and a second orientation with the ramped section of the first member positioned against the ramped section of the second member; the device including a greater height measured the exterior sides in the second orientation than in the first orientation, wherein the device length remains constant when moving between the first orientation and the second orientation.