Patent ID: 8262736

Claim:
An orthopedic implant for implantation at least in part between two adjacent bone masses, said implant comprising: a body having a leading end, a trailing end opposite said leading end, a mid-longitudinal axis, and a length between said leading and trailing ends of said body, said body having a mid-point bisecting the length of said body, said body having a first side portion adapted to contact one of the adjacent bone masses, a second side portion opposite said first side portion adapted to contact another one of the adjacent bone masses, and at least a third side portion between said first and second side portions, each of said first, second, and third side portions extending from said trailing end of said body and being spaced apart from one another to form a hollow interior therebetween, said hollow interior being configured to hold at least some bone growth promoting material therein, each of said first, second, and third side portions configured to move at least in part in a direction away from the mid-longitudinal axis of the body allowing for expansion of said body in at least three directions, said first, second, and third side portions having a collapsed position and an expanded position; and an expander at least in part within said hollow interior, said expander configured to cooperatively engage an instrument adapted to be inserted through said trailing end of said body to engage and to move said expander from a position proximate said leading end when said body is in the collapsed position away from said leading end and toward said trailing end of said body to place said body in the expanded position, said, expander adapted, to contact and to move said first, second, and third side portions away from the mid-longitudinal axis of said body, said first, second, and third side portions of said body adapted to cooperatively engage said expander to locate said expander at a fixed position along the length of said body, said fixed position being closer to the mid-point of said implant than to said leading end of said implant, said first, second, and third side portions of said body adapted to resist dislodgment of said expander from that location when said implant is in the expanded position, said expander adapted to hold at least a portion of said first, second, and third side portions apart so as to maintain the expanded position of said body and to resist the collapse of said body to the collapsed position when said body is in the expanded position, when said body is in the expanded position said hollow interior being substantially unobstructed by any mechanism to move said expander so as to permit growth of bone through a portion of said hollow interior between said expander and said trailing end and through a portion of said hollow interior between said expander and said leading end of said body.