An expandable laminoplasty device has a superior plate, an inferior plate, threaded or racked gear post having external threads or gear teeth, the post affixed to one of the superior plate or the inferior plate, and a gear nut or pinion gear, the gear has internal threads or external gear teeth configured to engage external threads or gear teeth of the post. The gear is held in one of the superior plate or inferior plate not affixed to the post and wherein the superior plate or inferior plate not affixed to the post has an end with a slot or channel to receive the post and a side opening to receive and hold the gear.