Paragraph Number

87

Referring to FIGS. 10-14, a hole forming guide 200 includes a body 202 defining hole axes 204, 206 along which a hole forming tool may be guided. In the illustrative example of FIGS. 10-14, the axes 204, 206 are defined by cylindrical guide holes 208, 210. The guide holes 208, 210 are operable to receive a hole forming tool such as a punch or drill and constrain the hole forming tool to longitudinal motion along the axes 204, 206 to form holes in an underlying bone. The axes 204, 206 are angled to correspond to the divergent legs of the fastener of FIGS. 1-9. The inboard surfaces of the guide holes 208, 210 have a guide hole inboard surface leading end spacing 212 at the leading end 214 of the guide 200 that is equal to or greater than the inboard surface trailing end spacing 165 of the fastener. If the guide hole inboard surface leading end spacing 212 is equal to the fastener leg inboard surface trailing end spacing 165, the inboard surfaces 128, 130 of the fastener legs will just touch the inboard surfaces of the bone holes when the fastener leg trailing ends are inserted flush with the bone surface. Further seating of the fastener legs below the surface of the bone will result in compression of the bone between the fastener legs. Likewise, if the guide hole inboard surface leading end spacing 212 is greater than the fastener leg inboard surface trailing end spacing 165, the inboard surfaces 128, 130 of the fastener legs will just touch the inboard surfaces of the bone holes when the fastener leg trailing ends are proud of the bone surface. Further insertion of the fastener until the trailing ends of the legs are flush with the bone surface will result in compression of the bone. The amount of compression for a given insertion depth of the fastener may be determined by selecting the relationship of guide hole inboard surface leading end spacing 212 to fastener leg inboard surface trailing end spacing 165. With the included angle between the leg inboard surfaces matching the included angle between the hole inboard surfaces, the compression of the bone between the fastener legs is uniform at all positions between the legs normal to the insertion axis and inserting the bone fastener does not create a relative bending moment between the first and second bone portions. An insertion axis is an axis along which an object is inserted. An insertion axis may also be the same axis used to extract an object. The guide 200 further includes a guide slot 216 connecting the holes 208, 210. The slot 216 may be used to guide a chisel, broach, saw or other cutting tool to remove bone and form a connecting slot between bone holes formed using the guide holes 208, 210 for receiving the fastener body 104. Alignment notches 218 are provided to indicate the center of the guide 200. Fixation holes 220 are provided to receive fixation pins or screws to fix the guide in position on a bone.

Added by DJM 12 2021