An intervertebral scaffolding system is provided having a central beam having a proximal portion having an end, a grafting portion having a top and a bottom, a distal portion having a end, a central beam axis, a graft distribution channel having an entry port at the end of the proximal portion, a top exit port at the top of the grafting portion, and a bottom exit port at the bottom of the grafting portion. These systems can also include a laterovertically-expanding frame operable for a reversible collapse from an expanded state into a collapsed state. The expanded state, for example, can be configured to have an open graft distribution window that at least substantially closes upon the reversible collapse.