in fig6 b the north south east and west pole markings will be employed later to ensure proper orientation of the allograft plug 22 1 in this regard the orientation of the markings on both the allograft 22 and the condyle 10 must be substantially identical to one another if an orientation discrepancy exists then the pin 26 may be reset in the allograft 22 and fresh markings for the plug 22 1 drawn once the orientations have been confirmed the cutter guide 14 is rotated by hand to drill through both the articulating surface of the patient 39 s condyle 10 and the allograft 22 as shown in fig7 a and 7 b respectively until the cutter guide 14 is against the cortical bone the same size drill bit and coring reamer 30 is then selected from the instrument kit the drill bit 30 is mounted on the cannulated drill 18 and placed over the steinmann pin 16 embedded in the patient condyle 10 the drill bit 30 is advanced through the articular surface of the condyle 10 while under constant irrigation from irrigator 32 and then through the cortical bone into the cancellous bone as depicted in fig8 a it is.