Spinal rod insertion instrument

A surgical instrument for urging a longitudinal spinal rod into a bone fastener, the fastener including a head and a bone engaging portion, the head including a bottom surface, two lateral side walls defining a U-shaped channel, and a top opening, each of the lateral side walls including opposing end faces having a recess formed therein, each of the recesses including a pair of end walls and a seat disposed therebetween, each of the seats being in communication with the U-shaped channel, the instrument comprising:

• a holder assembly for engaging the bone fastener, the holder assembly comprising a pair of pivotably connected members arranged in a scissor type configuration having a first end and a second end, at least a portion of the first end includes a region having grooves and wherein the second end is sized and configured to engage the head of the bone fastener, the second end of the holder assembly including a pair of jaws each having an extension formed thereon for engaging the recesses formed on the lateral side walls of the bone fastener so that the holder assembly can engage the bone fastener without extending over the U-shaped channel, the extensions being sized and configured to engage the seats formed on the head of the bone fastener;
• a reducing mechanism for moving the spinal rod with respect to the bone fastener, the reducing mechanism comprising a rod contacting member, an outer support structure, and a vertical drive mechanism, the rod contacting member having a first end and a second end, the first end being sized and configured to contact the spinal rod, the outer support structure having a first end, a second end, a drive region, and a holder region wherein the holder region includes a first opening in the first end of the support structure for receiving at least a portion of the first end of the holder assembly and the drive region includes a cavity for receiving at least a portion of the vertical drive mechanism, the vertical drive mechanism including a longitudinal member configured to engage the grooved region of the holder assembly so that movement of the vertical drive mechanism moves the reducing mechanism with respect to the holder assembly in a first direction;
• and
• a horizontal drive mechanism having a shaft and a lateral support member, the shaft having a first end, a second end, and at least a partially threaded section, the first end of the shaft being connected to the outer support structure, and the lateral support member connecting directly or indirectly to the rod contacting member, wherein the partially threaded section of the shaft interacts with the lateral support member so that operation of the horizontal drive mechanism laterally moves the rod contacting member in a second direction;
• wherein the rod contacting member is an H-shaped member incorporating a pair of parallel brackets, one of the brackets including a hook on an end thereof, the hook being sized and configured to engage the spinal rod, the other bracket including a recess formed on an end thereof, the recess being sized and configured to contact the spinal rod, the recess being different than the hook;
• and
• wherein the second end of the rod contacting member connects to a pair of intermediary support members, each of the intermediary support members being in the form of a triangular member having a first, second and third corner, wherein the first corner is fixedly connected to the rod contacting member, the second corner is pivotably connected to the outer support structure and the third corner is connected to the horizontal drive mechanism.