Patent ID: 6395035
Filing Date: 2002-05-28
Classification: A61F

Abstract:
An intervertebral fusion cage for implantation in an intervertebral space between adjacent vertebrae, comprising:a body having a central axis, a first outer surface, and a first stiffness; a central cavity for containing graft material having a second outer surface and extending through the body coaxial to the central axis; a circumferential sidewall between the first outer surface and the second outer surface; an upper and a lower contact surface perpendicular to the central axis, wherein the upper and lower contact surfaces contact the adjacent vertebrae; and a plurality of slots transverse to the central axis, each of the slots having a minimal width and extending through the circumferential sidewall, wherein upon compression of the body along the central axis, the slots close to their respective minimal widths providing the body a second stiffness greater than the first stiffness.