contemplated that the injection of pmma 170 is complete and that trocar 166 has been removed furthermore fig9 contemplates if desired the further movement of first hollow rod 54 along the direction of arrow h to further embed end 62 into vertebral body 126 or the further movement of second hollow rod 58 along the direction of arrow i to further embed end 90 into vertebral body 130 a number of other embodiments are contemplated for example tapered section 70 or tapered section 102 or both of them could be provided with exterior threads such that rotation of a respective rod will bite into a respective surrounding vertebral body such threading would further mechanically secure device 50 another embodiment is shown in fig1 wherein a modified version of device 50 shown as device 50 a is provided in device 50 a crimp 122 is obviated and in its place a set screw 200 a is provided for affixing rod 54 to rod 58 one or more channels 204 a or the like may be provided about the periphery of rod 58 in order to receive set screw 200 a such that when set screw 200 a is fully tightened its tip occupies channel 204 a and thereby secures rod 54 to rod 58 a further alternative to crimping is shown in fig1 and fig1 fig1 shows a side view of a lock ring 208 b having a hinge 212 b and a clasp 216 b lock ring 208 b can be unclasped as shown in fig1 and the halves opened so that lock ring 208 b can be placed around rod 58 the diameter of lock ring 208 b and the clasp 216 b are sized.