Spinal fixation plates

Patent metadata

Field	Value
Publication number	US-9320549-B2
Application number	US-201514700419-A
Country	US
Kind code	B2
Filing date	Apr 30, 2015
Priority date	Mar 31, 2003
Publication date	Apr 26, 2016
Grant date	Apr 26, 2016

Abstract

Spinal fixation plates for maintaining adjacent vertebrae in and fixed position are provided. In an exemplary embodiment, the plate includes opposed superior and inferior portions that are angled in a direction anterior to an anterior face of a mid-portion of the plate. The plate also includes a curvature formed therein about a longitudinal axis in a sagittal plane thereof. In use, when the plate is attached to adjacent vertebrae, the angle of the superior and inferior portions and the curvature in the plate are effective to position one or more thru-bores formed in the superior and inferior portions at the anterior rims of the adjacent vertebrae. In another embodiment, a spinal fixation plate is provided that is adapted to engage and mate to a fusion cage or other vertebral implant disposed between adjacent vertebra. The present invention also provides spinal fixation kits or assemblies, and methods for implanting the same.

First claim

What is claimed is:

1. A spinal fixation assembly, comprising:
a fusion cage having an anterior face and a posterior face, and a superior face and an inferior face, the fusion cage being configured to be positioned between adjacent vertebrae such that at least a portion of the superior face contacts an endplate of a superior vertebra and at least a portion of the inferior face contacts an endplate of an inferior vertebra, the fusion cage having a first recess disposed in the superior face and a second recess disposed in the inferior face; and
a spinal fixation plate having
an anterior face and a posterior face,
at least one bone screw aperture extending through the anterior and posterior faces for receiving a bone screw configured to mate the spinal fixation plate to bone, the at least one bone screw aperture being obliquely angled relative to the posterior and anterior faces of the spinal fixation plate,
a central opening being disposed substantially at a center of the spinal fixation plate, and
first and second arms extending outward from the posterior face of the plate, the first and second arms being configured to slidably contact the fusion cage such that the first arm extends across and contacts the first recess of the fusion cage and the second arm extends across and contacts the second recess of the fusion cage.

2. The spinal fixation assembly of claim 1 , wherein the at least one bone screw aperture comprises first and second bone screw apertures positioned on opposite sides of the central opening.

3. The spinal fixation assembly of claim 1 , wherein the first and second arms each have a central longitudinal axis that is non-parallel to a central longitudinal axis of the at least one bone screw aperture.

4. The spinal fixation assembly of claim 1 , wherein the superior and inferior faces of the fusion cage include bone engaging surface features formed thereon.

5. The spinal fixation assembly of claim 1 , wherein the at least one bone screw aperture has an inner sidewall that is substantially concave for polyaxially seating a bone screw.

6. The spinal fixation assembly of claim 1 , further comprising at least one locking feature configured to prevent the spinal fixation plate from moving relative to the fusion cage in the direction substantially perpendicular to the posterior face of the fusion cage.

7. The spinal fixation assembly of claim 1 , wherein when the first and second arms are received in the first and second recesses, the first and second arms engage the fusion cage.

8. A spinal fixation assembly, comprising:
a fusion cage having superior and inferior bone-contacting surfaces, and at least one arm-guide formed therein;
a spinal fixation plate having first and second bone screw bores formed therein, and at least one arm formed thereon and configured to extend into the at least one arm-guide in the fusion cage, the first and second screw bores each having a central longitudinal axis that extends at an acute angle relative to first and second faces of the spinal fixation plate; and
first and second bone screws configured to extend respectively through the first and second bone screw bores for mating the spinal fixation plate to bone;
wherein the spinal fixation plate includes an opening formed therein and positioned along a horizontal longitudinal axis of the plate and a screw received in the opening;
wherein the first and second bone screw bores are offset from the horizontal longitudinal axis, the first bone screw bore being positioned on a first side of the horizontal longitudinal axis and the second bone screw bore being positioned on a second side of the horizontal longitudinal axis;
wherein, when the first and second bone screws are disposed through the first and second bone screw bores, a distance between each of the first and second bone screws and one of the superior and inferior surfaces of the fusion cage increases in a direction from the second face of the spinal fixation plate to distal ends of the first and second bone screws.

9. The spinal fixation assembly of claim 8 , wherein the at least one arm has a central longitudinal axis that is non-parallel to a central longitudinal axis of each of the first and second bone screw bores.

10. The spinal fixation assembly of claim 8 , wherein when the at least one arm of the spinal fixation plate is coupled to the at least one arm guide, the at least one arm is flush with an outer surface of the fusion cage.

11. The spinal fixation assembly of claim 8 , wherein the superior and inferior surfaces of the fusion cage include bone engaging surface features formed thereon.

12. The spinal fixation assembly of claim 8 , wherein the first and second bone screw bores each have an inner sidewall that is substantially concave, and wherein the first and second bone screws each have a head with a substantially convex outer surface for seating within the first and second bone screw bores.

13. The spinal fixation assembly of claim 8 , further comprising a central bore formed in the fusion cage, wherein the opening formed in the spinal fixation plate is configured to be coaxially aligned with the central bore.

14. The spinal fixation assembly of claim 8 , further comprising at least one pin configured to lock the spinal fixation plate relative to the fusion cage, thereby preventing the spinal fixation plate from moving relative to the fusion cage in the direction substantially perpendicular to a first face of the fusion cage.

15. A spinal fixation assembly, comprising:
a fusion cage having an anterior face and a posterior face, and a superior face and an inferior face, the superior face comprising a superior-facing bone-engaging surface and a superior-facing recessed surface that is open to a superior end of the cage and the inferior face comprising an inferior-facing bone-engaging surface and an inferior-facing recessed surface that is open to an inferior end of the cage, the fusion cage being configured to be positioned between adjacent vertebrae such that the superior-facing bone-engaging surface contacts an endplate of a superior vertebra and the inferior-facing bone-engaging surface contacts an endplate of an inferior vertebra; and
a spinal fixation plate having
an anterior face and a posterior face,
at least one bone screw aperture extending through the anterior and posterior faces for receiving a bone screw configured to mate the spinal fixation plate to bone, the at least one bone screw aperture being obliquely angled relative to the posterior and anterior faces of the spinal fixation plate,
a central opening being disposed substantially at a center of the spinal fixation plate, and
first and second arms extending outward from the posterior face of the plate, the first and second arms being configured to slidably contact the fusion cage such that the first arm extends along the superior-facing recessed surface of the fusion cage and the second arm extends along the inferior-facing recessed surface of the fusion cage.

16. The spinal fixation assembly of claim 15 , wherein when the arms of the spinal fixation plate contact the fusion cage, a superior surface of the first arm is flush with the superior bone-engaging surface of the fusion cage and an inferior surface of the second arm is flush with the inferior bone-engaging surface of the fusion cage.

17. The spinal fixation assembly of claim 15 , wherein the at least one bone screw aperture comprises first and second bone screw apertures positioned on opposite sides of the central opening.

18. The spinal fixation assembly of claim 15 ,

Assignees

• Depuy Synthes Products Inc

Inventors

• Fraser Robert D
• Malone John D
• Serhan Hassan A
• Techiera Richard C

Classifications

• A61F2002/30593

  hollow · CPC title

• A61F2002/305

  Snap connection · CPC title

• A61F2002/30563

  having elastic means or damping means, different from springs, e.g. including an elastomeric core or shock absorbers · CPC title

• A61F2220/0033

  made by longitudinally pushing a protrusion into a complementary-shaped recess, e.g. held by friction fit · CPC title

• A61F2/4455

  for the fusion of spinal bodies, e.g. intervertebral fusion of adjacent spinal bodies, e.g. fusion cages (intervertebral discs A61F2/442) · CPC title