Intervertebral disc implants and tooling
A kit for preparing an intervertebral disc space for receiving an implant ( 100 ) includes a plurality of trials ( 152 ) having different sizes. Each trial ( 152 ) includes a body ( 154 ) insertible into an intervertebral disc space, the body ( 154 ) having a leading end ( 162 ), a trailing end ( 164 ), a top surface ( 156 ) and a bottom surface ( 160 ), the top surface of the body having a first groove ( 176 ) formed therein. Each implant also includes a flange ( 166 ) secured to the trailing end ( 164 ) of the body ( 154 ), the flange ( 166 ) having a first channel ( 180 ) aligned with the first groove ( 176 ), wherein each of the different sized trials has a different flange thickness. The flange thickness controls advancement of a cutting tool such as a chisel ( 192 ) into the first groove at the top surface of the trial body, which controls the depth of the cut into vertebral bone.
1. A method of performing spinal surgery, comprising:
preparing a disc space between first and second vertebral bodies;
attaching first and second elements of an artificial disc to an inserter head such that the inserter head holds together the first and second elements as a single implantable unit, wherein a straight resilient member of the inserter head causes at least one of the first and second elements to press against another portion of the inserter head;
after the attaching step, inserting a trailing end of the inserter head into a leading end of an inserter handle;
inserting the first and second elements of the artificial disc into the disc space such that the first element engages the first vertebral body and the second element engages the second vertebral body; and
disengaging the inserter head from the first and second elements so that they are free to move relative to each other.
2. The method of claim 1 , wherein the preparing step includes:
inserting a trial in the disc space, and
cutting a portion of the first vertebral body while the trial remains within the disc space so to form an opening in the first vertebral body.
3. The method of claim 2 , wherein the inserting step includes inserting a portion of the first element into the opening of the first vertebral body.
4. The method of claim 1 , further comprising selecting the artificial disc from a plurality of artificial discs having first and second elements of differing sizes.
5. The method of claim 1 , wherein the first element includes a first articular surface, and the second element includes a second articular surface, the first and second articular surfaces being configured to articulate with each other in flexion, extension, lateral bending, and axial rotation of the first and second vertebral bodies.
6. The method of claim 1 , wherein the trailing end includes a tapered stem, and the leading end includes a tapered opening.
7. The method of claim 1 , wherein the disengaging step includes advancing a pusher rod through the leading end of the inserter handle and the trailing end of the inserter head.
8. The method of claim 1 , further comprising connecting the inserter head to the first and second elements by sliding pins on the inserter head into respective openings in the first and second elements.
9. A method of performing spinal surgery, comprising:
preparing a disc space between first and second vertebral bodies of a cervical spine;
attaching first and second elements of an artificial disc to an inserter head such that the inserter head holds together the first and second elements as a single implantable unit, wherein a straight resilient pin of the inserter head presses the first element again a sloping surface of the inserter head;
inserting a trailing end of the inserter head into a leading end of an inserter handle while the first and second elements are attached to the inserter head;
inserting the first and second elements of the artificial disc into the disc space such that the first element engages the first vertebral body and the second element engages the second vertebral body; and
disengaging the inserter head from the first and second elements.
10. The method of claim 9 , further comprising selecting the head and artificial disc from a plurality of head and artificial disc assemblies of different sizes.
11. The method of claim 9 , wherein the trailing end includes a tapered stem, and the leading end includes a tapered opening.
12. The method of claim 9 , wherein the disengaging step includes advancing a pusher rod through the leading end of the inserter handle and the trailing end of the inserter head.
13. The method of claim 9 , further comprising connecting the inserter head to the first and second elements by sliding pins on the inserter head into respective openings in the first and second elements.
14. A method of performing spinal surgery, comprising:
preparing a disc space between first and second vertebral bodies;
holding together first and second elements as a single implantable unit with an inserter head, wherein the inserter head includes a straight resilient member that presses the first element against another portion of the inserter head;
engaging a trailing end of the inserter head with a leading end of an inserter handle by sliding the leading end over the trailing end while the inserter head simultaneously holds the first and second elements of an artificial disc in a fixed relationship with each other when the inserter handle engages the inserter head, wherein the trailing end includes a tapered stem, and the leading end includes a tapered opening;
inserting the first and second elements of the artificial disc into the disc space such that the first element engages the first vertebral body and the second element engages the second vertebral body; and
disengaging the inserter head from the first and second elements so that they are allowed move relative to each other and with their respective first or second vertebral body.
15. The method of claim 14 , further comprising selecting the head and artificial disc from a plurality of head and artificial disc assemblies of different sizes.
16. The method of claim 14 , wherein the disengaging step includes advancing a pusher rod through the leading end of the inserter handle and the trailing end of the inserter head.
17. The method of claim 14 , further comprising connecting the inserter head to the first and second elements by sliding pins on the inserter head into respective openings in the first and second elements.