Patent ID: 7731752

Claim:
An implant positionable between first and second vertebral members, the implant comprising: a first member including a first sidewall that extends around and forms a first interior space, the first member also including a first chamber within the first interior space that is at least partially spaced away from the first sidewall; a second member including a second sidewall that extends around and forms a second interior space, the second member also including a second chamber within the second interior space that is at least partially spaced away from the second sidewall; a third member including a third sidewall that extends around and forms a third interior space, the third member also including a third chamber within the third interior space that is at least partially spaced away from the third sidewall; the members positionable between collapsed and expanded orientations; the collapsed orientation comprising the third member nested within the second interior space and the second member nested within the first interior space with the first, second, and third sidewalls overlapping in a triple ply; the expanded orientation comprising the third member extending from the second member and the second member extending from the first member with the third sidewall being spaced apart from the first sidewall; the first, second, and third chambers constructed to mate together to form an enclosed chamber.