INTERVERTEBRAL DISC IMPLANTS AND TOOLING

1 . A kit for preparing an intervertebral disc space for receiving an implant comprising:

a plurality of trials having different sizes, each said trial comprising:

a body insertible into an intervertebral disc space, said body having a leading end, a trailing end, a top surface and a bottom surface, said top surface of said body having a first groove formed therein; and

a flange secured to said trailing end of said body, said flange having a first channel aligned with said first groove, wherein each of said different sized trials has a different flange thickness.

2 . The kit as claimed in claim 1 , wherein said first groove extends between said leading and trailing ends of said body.

3 . The kit as claimed in claim 1 , wherein said top surface of said body tapers toward said bottom surface of said body between said trailing end and said leading end of said body.

4 . The kit as claimed in claim 1 , further comprising second and third grooves formed in said bottom surface of each said body, wherein said first groove is offset from said second and third grooves.

5 . The kit as claimed in claim 4 , wherein said second and third grooves are spaced from one another.

6 . The kit as claimed in claim 4 , wherein said flange includes a second channel aligned with said second groove in said body and a third channel aligned with said third groove in said body.

7 . The kit as claimed in claim 1 , wherein said first channel has an upper end having a first width and a lower end having a second width that is less than the first width.

8 . The kit as claimed in claim 7 , wherein said first channel has a width that is substantially the same as the first width of said first channel.

9 . The kit as claimed in claim 6 , wherein said second channel has a lower end having a first width and an upper end having a second width that is less than the first width of said second channel, and wherein said third channel has a lower end having a first width and an upper end having a second width that is less than the first width of said third channel.

10 . The kit as claimed in claim 9 , wherein said second groove has a width that is substantially the same as the first width of said second channel and said second groove has a width that is substantially the same as the first width of said third channel.

11 . An inserter head for an intervertebral disc implant comprising:

a body having a leading end with a concave surface;

said concave surface having an upper end and a lower end;

a first pin projecting from said concave surface adjacent said upper end of said concave surface;

a pair of second pins spaced from one another and projecting from said concave surface adjacent said lower end of said concave surface;

a wedge projecting from said concave surface and being disposed between said first pin and said pair of second pins.

12 . The inserter head as claimed in claim 11 , wherein said first pin is resilient.

13 . The inserter head as claimed in claim 11 , further comprising:

a first flange projecting upwardly from said body; and

a second flange projecting downwardly from said body, wherein said first and second flanges are adapted for engaging vertebral bone for limiting advancement of said inserter head into an intervertebral disc space.

14 . The inserter head as claimed in claim 11 , further comprising a stem projecting from a trailing end of said inserter head for coupling said inserter head to a handle.

15 . A combination inserter head and intervertebral disc implant comprising:

an intervertebral disc implant having a top element with a posterior end, an anterior end, an opening in the anterior end, a bone engaging surface and an articulating surface;

said intervertebral disc implant having a bottom element with a posterior end, an anterior end, a pair of spaced openings in the anterior end, a bone engaging surface and an articulating surface that opposes the articulating surface of the top element;

said inserter head including a body having a leading end with a concave surface, said concave surface having an upper end and a lower end;

said inserter head having a first pin projecting from said concave surface adjacent said upper end of said concave surface, a pair of second pins spaced from one another and projecting from said concave surface adjacent said lower end of said concave surface, and a wedge projecting from said concave surface and being disposed between said first pin and said pair of second pins, wherein said first pin is disposed in said opening of said top element of said implant and said pair of second pins are disposed in said pair of openings in said bottom element of said implant.

16 . The combination as claimed in claim 15 , wherein said first pin is resilient and urges said top element of said implant against said wedge of said inserter head.

17 . The combination as claimed in claim 15 , wherein said pair of spaced second pins on said inserter head are spaced from one another by a first distance, and said, pair of openings in said lower element of said implant are spaced from one another by a second distance that is different than the first distance for forming a friction lock between said pair of second pins and said bottom element.

18 . The combination as claimed in claim 17 , wherein the first distance is greater than the second distance.

19 . The combination as claimed in claim 17 , wherein the first distance is less than the second distance.

20 . A kit comprising:

a plurality of two-part intervertebral disc implants having different sizes; and

a plurality of inserter heads having different sizes, each said inserter head being adapted for holding together one of said two-part intervertebral disc implants as a single implantable unit, wherein each said inserter head has indicia corresponding to the size of said intervertebral disc implant held by said inserter head.

21 . The kit as claimed in claim 20 , wherein said indicia includes a color code.

22 . The kit as claimed in claim 20 , wherein said indicia includes text indicating the size of said intervertebral disc implant held by said inserter head.

23 . The kit as claimed in claim 20 , wherein each said intervertebral disc implant has a top element including a bone engaging surface, an articulating surface and an opening at an anterior end thereof, and a bottom element including a bone engaging surface, an articulating surface and a pair of openings at an anterior end thereof, wherein said inserter head includes pins insertible into the openings at said anterior ends for holding said articulating surfaces of said top and bottom elements in contact with one another.

24 . A method of performing spinal surgery comprising the steps:

inserting a trial in an intervertebral disc space between two adjacent vertebrae;

cutting a portion of at least one vertebrae while the trial is in the intervertebral disc space;

removing the trial; and

inserting a two-part intervertebral disc implant in the intervertebral disc space.

25 . The method of claim 24 , further comprising the step of attaching the two-part intervertebral disc implant to an inserter head having a size corresponding to the implant.