Expandable fusion device and method of installation thereof

A spinal implant system comprising:

• a first endplate including an upper surface and a lower surface, wherein the upper surface includes surface protrusions, wherein a first through opening extends between the upper surface and the lower surface of the first endplate, wherein the first through opening is the only through opening that extends between the upper surface and the lower surface of the first endplate;
• a second endplate including an upper surface and a lower surface, wherein the lower surface includes surface protrusions, wherein a second through opening extends between the upper surface and the lower surface of the first endplate, wherein the second through opening is the only through opening that extends between the upper surface and the lower surface of the second endplate;
• a middle portion that extends between the first endplate and the second endplate, wherein the middle portion comprises an anterior end, a posterior end, a first sidewall extending between the anterior end and the posterior end of the middle portion, and a second sidewall extending between the anterior end and the posterior end of the middle portion, wherein a third through opening extends between the anterior end, the posterior end, and the first and second sidewalls,
• wherein the middle portion is single unitary member,
• wherein the middle portion comprises a first ramped surface in contact with the first endplate an second ramped surface in contact with the second endplate,
• wherein translation of the middle portion along a longitudinal axis extending through the middle portion, from a first position to a second position causes the first endplate to separate away from the second endplate, and
• wherein at least a portion of the first, second, and third through openings are aligned along an axis extending vertically through the middle portion when the middle portion is in the second position.