Patent ID: 8092533

Claim:
An implant for spacing apart vertebral members comprising: a body including an exterior surface and an interior region, the exterior surface including opposing contact surfaces configured to contact against the vertebral members when the body is inserted into a patient; a relief cut contained within the body and extending from the exterior surface inward to a terminal end that is disposed between the opposing contact surfaces; the relief cut having a superior side and an inferior side connected by the terminal end; first and second shims positioned in the relief cut and each slidably engaged with the relief cut; a stiffness of the implant being adjustable from a first stiffness with the relief cut being empty, a second stiffness with the first shim positioned in the relief cut, and a third stiffness with both the first and second shims positioned in the relief cut; a height of the implant with the first and second shims positioned in the relief cut is not greater than a distance between the opposing contact surfaces; wherein the relief cut is sized to simultaneously receive both the first and second shims; wherein, if the first and second shims are removed from the relief cut, the superior and inferior sides of the relief cut directly face each other.