An apparatus includes an elongate member having a portion configured to be deformed from a first configuration to a second configuration. In one variation, the apparatus includes an outer body, defining an interior region, and an inner body. A portion of the outer body is configured to be disposed between adjacent spinous processes. The inner body is disposed within the interior region of the outer body. A distal end portion of the inner body is coupled to a distal end portion of the outer body. A proximal end portion of the inner body configured to removably receive a tool to move the outer body between a collapsed configuration and an expanded configuration.