Patent ID: 7094257

Claim:
An expandable intervertebral implant, the implant comprising: a) an external member and an internal member; and b) an interlocking teeth structure formed on each of the external and internal members along which the external member and the internal member are adjustably engaged, the interlocking teeth structure arranged to permit expansion of the intervertebral implant along a direction of expansion, wherein: the internal member includes an internal base wall, first and second internal walls that extend from the internal base wall along a length of the base wall, wherein the first and second internal walls each have a free end and an attached end, the attached end connected to the base wall and the free end extending from the base wall in a generally perpendicular orientation; a flexible region in the internal member defined by a pair of slots formed adjacent to the attached ends of the first and second internal walls and extending along the length of the internal member base wall, wherein the flexible region provides for lateral displacement of the free ends of the first and second internal walls; the interlocking teeth structures formed on the external and internal members include external and internal engagement surfaces configured to engage one another to lock the implant in an expanded configuration against a compressive force applied to the internal and external members along a direction opposite the direction of expansion; and the external and internal engagement surfaces are arranged in a non-perpendicular orientation relative to the direction of implant expansion.