of gear 42 the housing 30 may include a slot suitably fashioned to receive gear 41 which itself receives bushing 43 fig3 illustrates a section detail view section b b of a driving gear mechanism 40 a and two pins 50 taken through the posterior aspect of a non enclosed horseshoe shaped housing 30 while section a a shows a driving gear mechanism 40 b and two pins 50 taken through the removably coupled faceplate 20 also illustrated is a more detailed example in mechanism 40 b of a cannulated and fenestrated pin 50 with drainage holes 51 to facilitate blood and or marrow transfer through the vertebral endplate and ultimately into the intervertebral body housing cage component to augment the supplemental bone tissue or a synthetic bone substitute used in conjunction with the patient 39 s natural osteoblastic processes in a spinal fusion procedure fig4 illustrates a similar gear mechanism 40 c with additional gears 44 are added to the assembly the additional gears 44 would permit a wider space between the two opposing pins 50 while maintaining a similar overall height of the device also additional gears allow for a different ratio of driver rotations versus that of the pin rotation and or forward advancement additional gears could be used with.