An implantable device (10, 300), comprising: a barrel (16, 306), the barrel having an upper portion and a lower portion; wherein the barrel (16, 306), is configured to transition from a collapsed form having a first height to an expanded form having a second height and wherein the second height is greater than the first height. a first plate (12, 302) having multiple projections (34, 324) extending from one side of the first plate(12, 302), the first plate (12, 302)comprising a first portion (26, 320) that extends from the upper portion and a second portion (28, 322) that extends form the lower portion; characterized in that the device further comprises an actuator assembly disposed in the barrel, the actuator assembly comprising a front ramped actuator (70, 342) in engagement with the barrel (16, 306), a rear ramped actuator (72, 344) in engagement with the barrel (16, 306), and a central screw (52, 340) that extends from the rear ramped actuator (72, 344) through the front ramped actuator (72, 344); a second plate (14, 304) having multiple projections (34, 324) extending from one side of the second plate(14, 304), the second plate configured to be received on the central screw (52, 340), wherein the second plate (14, 304) comprises an upper portion, a lower portion, a central portion connecting the upper portion and the lower portion, and a trunion assembly disposed in an opening in the central portion, wherein the trunion assembly comprises a housing for receiving the central screw (52, 340), a pair of chambers on either side of the opening, and a pair of ratchet pawls, each of the ratchet pawls being individual disposed in one of the chambers and configured to engage the central screw (52, 340)in the opening. a barrel (16, 306), the barrel having an upper portion and a lower portion; wherein the barrel (16, 306), is configured to transition from a collapsed form having a first height to an expanded form having a second height and wherein the second height is greater than the first height. a first plate (12, 302) having multiple projections (34, 324) extending from one side of the first plate(12, 302), the first plate (12, 302)comprising a first portion (26, 320) that extends from the upper portion and a second portion (28, 322) that extends form the lower portion; characterized in that the device further comprises an actuator assembly disposed in the barrel, the actuator assembly comprising a front ramped actuator (70, 342) in engagement with the barrel (16, 306), a rear ramped actuator (72, 344) in engagement with the barrel (16, 306), and a central screw (52, 340) that extends from the rear ramped actuator (72, 344) through the front ramped actuator (72, 344); a second plate (14, 304) having multiple projections (34, 324) extending from one side of the second plate(14, 304), the second plate configured to be received on the central screw (52, 340), wherein the second plate (14, 304) comprises an upper portion, a lower portion, a central portion connecting the upper portion and the lower portion, and a trunion assembly disposed in an opening in the central portion, wherein the trunion assembly comprises a housing for receiving the central screw (52, 340), a pair of chambers on either side of the opening, and a pair of ratchet pawls, each of the ratchet pawls being individual disposed in one of the chambers and configured to engage the central screw (52, 340)in the opening.