Implant assembly and method for use in an internal structure stabilization system
View Patent ↗An assembly for use in spinal stabilization procedures having first and second bone anchor assemblies. Embodiments of the first bone anchor assembly may include an anchor, a poly-axial head, including a cavity, mated with the anchor such that the anchor is movable relative to the poly-axial head. Embodiments of the second bone anchor assembly may include an anchor, a poly-axial head mated with the second anchor such that the anchor is movable relative to the poly-axial head, a slide ring rotatably mated in the second poly-axial head, and a connector slideably mated in the slide ring along a distal end, and having a proximal end having an enlarged portion. The connector may be movable from a first position axially inline with the second bone anchor to a second position wherein the enlarged portion of the connector rests in the cavity of the first poly-axial head.
1. An assembly for use in spinal stabilization procedures, comprising:
a first bone anchor assembly comprising:
a first anchor
a first poly-axial head mated with the anchor such that the anchor is movable in relation to the poly-axial head, the first poly-axial head including a cavity; and
a second bone anchor assembly comprising:
a second anchor;
a second poly-axial head mated with the second anchor such that the second anchor is movable in relation to said second poly-axial head;
a slide ring rotatably mated in the second poly-axial head;
a connector slidably mated in the slide ring along a distal end, and having a proximal end having an enlarged portion;
wherein the connector is movable from a first position axially inline with the second bone anchor to a second position wherein the enlarged portion of the connector rests in the cavity of the first poly-axial head, and wherein the first position is used to implant the first bone anchor assembly, and the second position used to hold the assembly in a fixed orientation; and
a snap ring in the first poly-axial head, the snap ring holding the enlarged portion of the connector in the cavity.
2. The assembly of claim 1 , further comprising locking caps inserted into the first and the second poly-axial heads, wherein the locking caps act to lock the elements of the first and second bone anchor assemblies into a fixed orientation.
3. The assembly of claim 2 , wherein said locking caps comprise:
a locking ring insertable into said second poly-axial head and operable to hold said slide ring, said first poly-axial head and said first anchor in a fixed orientation; and
a compression cap insertable into said locking ring and operable to hold said connector in a fixed orientation with said slide ring.
4. The assembly of claim 1 , further comprising an extension removably attached to the first poly-axial head assembly, the extension allowing access to the first bone anchor assembly after implantation.
5. The assembly of claim 4 wherein the extension comprises:
a tubular body having an attachment mechanism for attaching to the first poly-axial head; and
a locking mechanism for temporarily locking the extension with the first poly-axial head.
6. The assembly of claim 5 wherein the locking mechanism is a twist ring and a slider attached to the tubular body, the twist ring twistable to cause the slider to move between a first and second position, the first position temporarily locking the extension to the first poly-axial head, the second position allowing the extension to be disengaged from the first poly-axial head.
7. The assembly of claim 1 wherein the first anchor includes an off-axis guide from a tip of the first anchor out a side of the first anchor, the off-axis guide allowing the first anchor to be guided down a guide wire.
8. The assembly of claim 1 wherein the connector includes a drive mechanism mated to a drive mechanism of the second anchor when the connector is in the first position, the connector operable in the first position to transfer torque from a tool to the second anchor.
9. The assembly of claim 1 wherein the connector includes an engagement mechanism in the enlarged portion, the engagement mechanism for engaging with a connector transfer tool.
10. An assembly for use in spinal stabilization procedures, comprising:
a first bone anchor assembly comprising:
a first anchor
a first poly-axial head mated with the anchor such that the anchor is movable in relation to the poly-axial head, the first poly-axial head including a cavity; and
a second bone anchor assembly comprising:
a second anchor;
a second poly-axial head mated with the second anchor such that the second anchor is movable in relation to said second poly-axial head;
a slide ring rotatably mated in the second poly-axial head;
a connector slidably mated in the slide ring along a distal end, and having a proximal end having an enlarged portion;
wherein the connector is movable from a first position axially inline with the second bone anchor to a second position wherein the enlarged portion of the connector rests in the cavity of the first poly-axial head, and wherein the first position is used to implant the first bone anchor assembly, and the second position used to hold the assembly in a fixed orientation; and
wherein the connector includes a drive mechanism mated to a drive mechanism of the second anchor when the connector is in the first position, the connector operable in the first position to transfer torque from a tool to the second anchor.
11. The assembly of claim 10 , further comprising a snap ring in the first poly-axial head, the snap ring holding the enlarged portion of the connector in the cavity.
12. The assembly of claim 10 , further comprising locking caps inserted into the first and the second poly-axial heads, wherein the locking caps act to lock the elements of the first and second bone anchor assemblies into a fixed orientation.
13. The assembly of claim 12 , wherein said locking caps comprise:
a locking ring insertable into said second poly-axial head and operable to hold said slide ring, said first poly-axial head and said first anchor in a fixed orientation; and
a compression cap insertable into said locking ring and operable to hold said connector in a fixed orientation with said slide ring.
14. The assembly of claim 10 , further comprising an extension removably attached to the first poly-axial head assembly, the extension allowing access to the first bone anchor assembly after implantation.
15. The assembly of claim 14 , wherein the extension comprises:
a tubular body having an attachment mechanism for attaching to the first poly-axial head; and
a locking mechanism for temporarily locking the extension with the first poly-axial head.
16. The assembly of claim 15 , wherein the locking mechanism is a twist ring and a slider attached to the tubular body, the twist ring twistable to cause the slider to move between a first and second position, the first position temporarily locking the extension to the first poly-axial head, the second position allowing the extension to be disengaged from the first poly-axial head.
17. The assembly of claim 10 , wherein the first anchor includes an off-axis guide from a tip of the first anchor out a side of the first anchor, the off-axis guide allowing the first anchor to be guided down a guide wire.
18. The assembly of claim 10 , wherein the connector includes an engagement mechanism in the enlarged portion, the engagement mechfanism for engaging with a connector transfer tool.