US Patent 9839528 Variable lordosis spacer and related methods of use

An expandable fusion device may include a first endplate and a second endplate. The expandable fusion device may also include first and second ramps configured to mate with both the first and second endplates. The first ramp may include a mating feature having a first angle relative to a vertical axis, and the second ramp may include a mating feature having a second angle relative to the vertical axis such that the first angle is different from the second angle. In particular, the first and second ramps may be configured to provide for symmetrical expansion of the first and second endplates.