Expandable interbody spacer

An expandable interbody spacer for the spine is provided. The interbody spacer includes a housing, a top endplate and a bottom endplate. An actuator is located inside the housing between the top and bottom endplates. A locking screw is configured to drive the actuator and move the endplates between collapsed and expanded configurations. Variations of the expandable spacer are provided in which the endplates move bilaterally outwardly into uniform and parallel expansion along the latitudinal axis, the endplates angulate about a pivot point along a longitudinal axis such that the distal end of the spacer increases in height relative to the proximal end, and the endplates angulate about a pivot along a lateral axis such that the height along one lateral side of the spacer increases in height relative to the other lateral side.