An expandable implant (210, 410) includes top and bottom plates (220, 250, 420, 450) having angled inner surfaces (222, 252, 422, 452) that interact with expansion members (300, 302, 500, 502). The expansion members (300, 302, 500, 502) may be situated on an actuator (280, 480), and may include at least one vertical projection (312, 314, 512, 514) for interacting with a recess (230, 430) in the plates (220, 250, 420, 450). In some instances, rotation of the actuator (280, 480) in opposing directions about a longitudinal axis may cause the expansion members (300, 302, 500, 502) to move toward or away from one another, thereby resulting in separation or collapse of the top and bottom plates (220, 250, 420, 450). Pins (316, 516) may also be associated with the expansion members (300, 302, 500, 502) and received in respective slots (318, 518) in the plates (220, 250, 420, 450).