Patent ID: 7931688

Claim:
An expandable interbody fusion device for implantation into the intradiscal space between the opposing vertebral bodies in a spine, comprising: an upper plate having an outer surface configured to contact an upper vertebral body and a lower surface having a shaped configuration; a lower plate having an outer surface configured to contact a lower vertebral body and an upper support surface, said lower plate and said upper plate being initially engaged in a first releasable engagement; and at least one expansion member sized to be received into said device and supported on said upper support surface between said upper plate and said lower plate, and upon receipt therein to releasably disengage and displace said upper and lower plates, said expansion member including a plurality of resiliently deformable latch elements spaced successively along the direction of receipt; said expansion member forming, upon receipt into said device, a resilient ratcheting interlocking interface between said plurality of latch elements and the shaped configuration of the lower surface of said upper plate, and said expansion member upon such receipt further forming a second releasable engagement with said lower plate separate and apart from said interlocking interface.