US Patent 9138328 Radially expandable spinal interbody device and implantation tool

A spinal interbody device includes a base link having a first end and a second end, and a linkage including a first link having a first end and a second end and a second link having a first end and a second end. The first end of the first link is coupled to the first end of the base link at a first hinge, the second end of the first link is coupled to the first end of the second link at a second hinge; and the second end of the second link is coupled to the second end of the base link at a third hinge.