Methods and apparatus for immobilizing a synovial joint, such as a sacroiliac (SI) joint are disclosed. In one form, a multipiece fixation device, such as a dowel, includes multiple expandable fasteners that are configured to fix adjacent bones of a synovial joint with respect to one another. The expandable fasteners include expansion portions that are expanded radially via insertion of another expandable fastener or an expansion device to fix the expandable fasteners to the bone. The fixation device may be configured to provide for compression or distraction of the bones of the synovial joint while at the same time stabilizing the joint.
