An interbody spacer implant assembly for interbody fusion in a vertebral body and a method of insertion comprises a plurality of links and an elongated connector mechanism adapted to retain the plurality of links and allow the plurality of links to articulate with respect to one another. An interbody spacer implant apparatus for interbody fusion in a vertebral body comprises a plurality of individually articulating links and a connector mechanism adapted to retain the plurality of links and allow the plurality of links to articulate with respect to one another, wherein the connector mechanism is dimensioned and configured to have a length-to-width ratio greater than a length-to-width ratio of each of the plurality of links. The apparatus may further comprise an insertion rod adapted to insert the plurality of links and the connector mechanism into the vertebral body.