Spinal rod approximators

1. A tool for seating a spinal rod in a rod-receiving portion of a spinal implant, the tool comprising:

a body having a proximal end portion and a distal end portion, said distal end portion including a first and second flexible branch for gripping a spinal implant, said flexible branches being biased to a closed position, said flexible branches being spaced-apart a distance to form a first substantially U-shaped recess, said first substantially U-shaped recess opening at an end of the distal end portion and extending proximally from the end;

an inserter shaft slidably received within said body, said inserter shaft having a distal end adapted to hold a closure mechanism for said implant;

a threaded collar, adapted to couple said body and said inserter shaft, wherein said inserter shaft forces a spinal rod into the rod-receiving portion of said implant; and

a substantially cylindrical outer sleeve disposed about the distal end portion of the body and movable between a first position and a second position in which the outer sleeve surrounds the branches to inhibit separation of the first and second flexible branches, the outer sleeve including a pair of spaced-apart arms at a distal end of the outer sleeve, the arms defining a second substantially U-shaped recess, the second substantially U-shaped recess aligning with the first substantially U-shaped recess when the outer sleeve is in the second position to accommodate a spinal rod within the first substantially U-shaped recess and the second substantially U-shaped recess.

2. A tool for seating a spinal rod in a rod-receiving portion of a spinal implant, the tool comprising:

a body having a proximal and distal end portion, wherein an interior channel extends between the distal and proximal portions, said distal end portion having flexible branches for gripping a spinal implant and said proximal end portion having external threads, the flexible branches being spaced-apart a distance to form a first substantially U-shaped recess, the first substantially U-shaped recess opening at an end of the distal end portion and extending proximally from the end;

an inserter shaft slidable within said interior channel of the body having a proximal end portion, a distal end portion, and a transition zone located between said distal and proximal end portions, said transition zone having a diameter larger than the proximal end portion, said distal end portion adapted to hold a closure mechanism for the spinal implant;

a collar having an internally threaded hollow body and a central shaft attached to said hollow body, wherein said central shaft limits independent motion between said inserter shaft and said collar, wherein said diameter of the transition zone of the inserter shaft is greater than an inner diameter of the central shaft of the collar, said central shaft of the collar having a distal and a proximal portion, said proximal portion attached to said hollow body and said distal portion extending past said hollow body and having an abutment surface for engaging the transition zone portion of said inserter shaft; and

a substantially cylindrical outer sleeve disposed about the distal end portion of the body and movable between a first position and a second position in which the outer sleeve surrounds the flexible branches to inhibit separation of the branches, the outer sleeve including a pair of spaced-apart arms at a distal end of the outer sleeve, the arms defining a second substantially U-shaped recess, the second substantially U-shaped recess aligning with the first substantially U-shaped recess when the outer sleeve is in the second position to accommodate a spinal rod within the first substantially U-shaped recess and the second substantially U-shaped recess.

3. The tool of claim 2 wherein said flexible branches are biased in a closed position.

4. A tool for seating a spinal rod in a rod-receiving portion of a spinal implant comprising:

a body having a proximal and a distal end portion, said distal end portion having branches for gripping a spinal implant, wherein an interior channel extends between the distal and proximal ends, the branches being spaced-apart a distance to form a first substantially U-shaped recess, the first substantially U-shaped recess opening at an end of the distal end portion and extending proximally from the end;

an inserter shaft having a proximal and a distal end portion, said distal end portion adapted to hold a closure mechanism for the spinal implant, wherein said shaft is sized to fit within the interior channel of the body;

a guide mechanism co-operable with said shaft and said body whereby said guide mechanism limits an independent movement of the shaft within the body, the guide mechanism including a channel and a pin adapted to fit within said channel, the channel located on the body and extending parallel to a longitudinal axis of the body, the pin located on said shaft; and

a substantially cylindrical outer sleeve disposed about the distal end portion of the body and movable between a first position and a second position in which the outer sleeve surrounds the branches to inhibit separation of the branches, the outer sleeve including a pair of spaced-apart arms at a distal end of the outer sleeve, the arms defining a second substantially U-shaped recess, the second substantially U-shaped recess aligning with the first substantially U-shaped recess when the outer sleeve is in the second position to accommodate a spinal rod within the first substantially U-shaped recess and the second substantially U-shaped recess.

5. The tool of claim 4 wherein a portion of said channel branches off at an angle and reverses direction.

6. The tool of claim 5 wherein a point where said channel branches off corresponds to the point where the spinal rod is fully seated in the implant.

7. The tool of claim 5 wherein said angle is approximately 90 degrees.

8. The tool of claim 4 wherein the pin and channel prevent the shaft from being removed from the body.

9. The tool of claim 4 wherein the independent movement limited is a rotational orientation of the inserter shaft with respect to the body.

10. The tool of claim 4 wherein the independent movement limited is an axial translation of the inserter shaft with respect to the body.