A device for implantation in the vertebral column, comprising: - a cannulated body comprising a support portion extending laterally along an axis between first and second end portions, the body defining a cannula extending therethrough along the axis; - a barrel insert received within the cannulated body, the barrel insert having a pair of wing members mounted at a distal end of the barrel insert, the barrel insert translates linearly along the axis to move the wing members from a first, closed position to a second, open position, - wherein the pair of wing members is slidable and/or rotatable on the cannulated body and moveable from the first, closed position to the second, open position, - wherein in the second, open position the wing members extend beyond the support portion in a direction perpendicular to the axis to a greater extent than in the first, closed position; - wherein the device is configured and dimensioned to be inserted between adjacent spinous processes of the vertebral column in a lateral direction along the axis and is advanceable over a guidewire extending through the cannula to position the support portion in a predetermined position between the spinous processes, - wherein in such a predetermined position, the wing members of the first end portion are moveable from the first, closed position to the second, open position; - wherein when in the first, closed position the first end portion comprises a ramp on at least a portion of the outer surface configured and dimensioned to engage and separate the adjacent spinous processes when inserted and the wing members are moveable to the second, open position, - wherein in the second, open position the first end portion comprises a sidewall on at least a portion of an inner surface configured and dimensioned to engage a lateral surface of the adjacent spinous processes to limit lateral movement with respect thereto; and - wherein the second end portion comprises a flange having a sidewall so configured that when the device is inserted in a lateral direction, the sidewall of the second end portion contacts a side of a spinous process to limit movement of the device along axis (12. - a cannulated body comprising a support portion extending laterally along an axis between first and second end portions, the body defining a cannula extending therethrough along the axis; - a barrel insert received within the cannulated body, the barrel insert having a pair of wing members mounted at a distal end of the barrel insert, the barrel insert translates linearly along the axis to move the wing members from a first, closed position to a second, open position, - wherein the pair of wing members is slidable and/or rotatable on the cannulated body and moveable from the first, closed position to the second, open position, - wherein in the second, open position the wing members extend beyond the support portion in a direction perpendicular to the axis to a greater extent than in the first, closed position; - wherein the device is configured and dimensioned to be inserted between adjacent spinous processes of the vertebral column in a lateral direction along the axis and is advanceable over a guidewire extending through the cannula to position the support portion in a predetermined position between the spinous processes, - wherein in such a predetermined position, the wing members of the first end portion are moveable from the first, closed position to the second, open position; - wherein when in the first, closed position the first end portion comprises a ramp on at least a portion of the outer surface configured and dimensioned to engage and separate the adjacent spinous processes when inserted and the wing members are moveable to the second, open position, - wherein in the second, open position the first end portion comprises a sidewall on at least a portion of an inner surface configured and dimensioned to engage a lateral surface of the adjacent spinous processes to limit lateral movement with respect thereto; and - wherein the second end portion comprises a flange having a sidewall so configured that when the device is inserted in a lateral direction, the sidewall of the second end portion contacts a side of a spinous process to limit movement of the device along axis (12.