EXPANDABLE INTERBODY FUSION DEVICE WITH GRAFT CHAMBERS

摘要

An expandable interbody fusion device includes superior and inferior endplates that are configured to receive a sequentially inserted stack of expansion members or wafers in interlocking engagement. The expansion members are formed to each have a generally U-shaped rearward facing opening. The superior and inferior endplates have openings through their outer surfaces in at least partial alignment and communication with the rearward facing openings of the expansion members. The inferior endplate has a fully bounded cavity for telescoping receipt of the superior endplate. The inferior endplate also has a fully bounded channel extending through the rear endwall thereof in direct communication with the rearward facing opening of at least one expansion member for the receipt of bone graft material into the device to promote fusion between opposing vertebral bodies of the spine.

主权项

1. An expandable interbody fusion device for implantation into an intradiscal space between two opposing vertebral bodies of a spine, comprising:
a first endplate having an outer surface configured to contact one of said vertebral bodies and an opening extending through said outer surface; a second endplate having an outer surface configured to contact the other vertebral body and an inner support surface, said second endplate having opposing spaced apart sidewalls and opposing spaced apart front and rear endwalls defining therewithin a fully bounded interior cavity, said support surface being within said interior cavity, said first endplate being received within said interior cavity, said second endplate having at least one opening extending through said outer surface and said support surface and communicating with said interior cavity, said rear endwall defining therethrough a fully bounded channel in communication with said interior cavity, said first endplate being movable in an expansion direction relative to said second endplate toward the opposing vertebral body; at least one elongate expansion member having a front end and a rear end configured to be introduced through said channel into said interior cavity in an insertion direction that is substantially perpendicular to said expansion direction and supported by said support surface therewithin with the front end of said expansion member adjacent the front endwall of said second endplate and the rear end of said expansion member adjacent the rear endwall of said second endplate, said expansion member having an open rearward facing opening extending through the rearmost surface of said rear end and communicating with said channel and in at least partial alignment with said openings through said first endplate and said second endplate; and cooperating locking surfaces on said expansion member and one of said first endplate and said second endplate member to lock said expansion member in said device.