a structure as desired or suitable for the particular application as noted hereinabove with regard to the benefits of a two piece cannulated shaft in some embodiments the radially expandable region 112 may for example comprise a cage structure 140 as schematically illustrated in fig2 3 and 6 the cage structure 140 may comprise a plurality of thin struts 142 joined together or integrally manufactured to form a housing having spaces between the struts the cage structure 140 may benefit from needing a reduced quantity of force to cause longitudinal compression and subsequent plastic radial expansion thereof the cage structure 140 may further benefit from including spaces between the struts 142 to facilitate passage of bone cement or other fluid that may be forced through the bore 118 after expansion of the cage structure 140 other embodiments of the radially expandable region 120 may include other structures for example a smooth spaceless rigid housing a corrugated rigid housing or other structure in use in one embodiment a hole is drilled and tapped through a first bone for example an inferior facet of a vertebra on a left side of the vertebra and drilled into an adjacent second bone for example a superior facet and a pedicle on a left side of an adjacent vertebra the cannulated shaft 102 including the washer 104 is driven through the first facet and into the second facet via the head 106 with a drive device for example a hexagonal head drive device not shown the head 106 includes a socket 144 for example the hexagonal socket 144 illustrated in fig1 to accommodate the drive.