An implant for spacing apart skeletal structures. The implant includes a base, a rotatable member, and a connector. The base extends around at least a portion of the member, and the member is pivotally connected to the base by the connector. The member includes a first pair of opposing sides that have a first height that is smaller than or equal to a height of the base, and a second pair of opposing sides that have a second height larger than the base. The member is movable to a first rotational position with the first pair of opposing sides facing in the same direction as the sides of the base such that the member is shorter than or equal to the base. The member is also movable to a second rotational position with the second pair of opposing sides facing in the same direction as the sides of the base such that the member is taller than the base.