Spinal fixation system

• US 5,928,232 A
• Filed: 04/04/1996
• Issued: 07/27/1999
• Est. Priority Date: 11/16/1994
• Status: Expired due to Fees

• Current Assignee: Encore Medical Asset Corporation (Enovis Corp.)
• Original Assignee: Advanced Spine Fixation Systems, Inc. (Enovis Corp.)
• Inventors: Rinner, James A., Howland, Robert S., Tebbe, Shawn R.
• Primary Examiner(s): Tucker, Guy V.
• Application Number:
  US08/628,143
• Time in Patent Office: 1,209 Days
• Field of Search: 606/61, 606/60, 606/72, 606/73, 606/53, 623/17
• US Class Current: 606/276
• CPC Class Codes: A61B 17/7001 Screws or hooks combined with longitudinal elements which do not contact vertebrae A61B17/7058 takes precedence
• CPC Class Codes: A61B 17/7047 Clamps comprising opposed elements which grasp one vertebra between them
• CPC Class Codes: A61B 17/7049 Connectors, not bearing on the vertebrae, for linking longitudinal elements together A61B17/7055, A61B17/7053, A61B17/7019 take precedence
• CPC Class Codes: A61B 17/7056 Hooks with specially-designed bone-contacting part
• CPC Class Codes: A61B 17/7076 for driving, positioning or assembling spinal clamps or bone anchors specially adapted for spinal fixation
• CPC Class Codes: A61B 17/7091 for applying, tightening or removing longitudinal element-to-bone anchor locking elements, e.g. caps, set screws, nuts or wedges

Abstract

A spinal fixation system utilizing grapple hooks comprising a lower hook attached to the lamina on the caudal-side of a vertebra and an upper hook attached to the lamina on the cranial-side of a vertebra. The hooks clamp the vertebra lamina in the center. Thus, the hooks clamp the lamina at the spinous process which is the strongest part of the lamina. Bolts are provided for attaching the lower hook to the upper hook to thereby attach the lower and upper hooks to the vertebra and clamps for attaching the lower and upper hooks to spine rods. A spinal fixation kit is provided with a plurality of uniquely configured fixation systems to assure satisfactory fit to any vertebra of any patient, and specially designed tools are preferably provided to aide in a method of implanting the systems thereby reducing the time required for implantation.

Claims

1. A lamina hook for attachment to a vertebra which includes a cranial side, a sacral side, a lamina and a spinous process with first and second lateral sides, the lamina hook comprising:

a single upper hook for attachment to the lamina under the spinous process on the cranial side of the vertebra, the upper hook having first and second upper arms extending from the upper hook for extending outwardly from the lamina;

a single lower hook for attachment to the lamina under the spinous process on the sacral side of the vertebra, the lower hook having a first lower arm extending outwardly from the lower hook for extending from the lamina on the first lateral side of the spinous process and a second lower arm extending outwardly from the lower hook for extending from the lamina on the second lateral side of the spinous process; and

first and second means for attaching the upper hook to the lower hook, the first attaching means extending between the first arms of the upper and lower hooks on the first lateral side of the spinous process and the second attaching means extending between the second arms of the upper and lower hooks on the second lateral side of the spinous process.

2. A lamina hook as recited in claim 1 further comprising means for attaching a spine rod.

3. A lamina hook as recited in claim 2 wherein the spine rod attaching means comprises a clamp for attaching the spine rod.

4. A lamina hook as recited in claim 3 wherein the clamp is attached to at least one of the first and second arms of the lower hook.

5. A lamina hook as recited in claim 1 wherein the upper hook defines a triangle with an open center, the three sides of the triangle defined by the first and second arms and a third arm extending between the first and second arms.

6. A lamina hook as recited in claim 1 wherein each arm of the upper hook and the lower hook defines an aperture and the first and second means for attaching the upper hook to the lower hook comprises a pair of bolts extending through the apertures of the first and second arms of the upper and lower hooks.

7. A lamina hook as recited in claim 6 wherein the means for attaching the upper hook to the lower hook further comprises C-spacers that fit over a shaft over each of the bolts between the upper and lower hooks.

8. A lamina hook as recited in claim 6 wherein the means for attaching the upper hook to the lower hook further comprises a pair of lock washers to prevent rotation of the bolts.

9. A lamina hook for attachment to a vertebra which includes a cranial side, a sacral side, a lamina and a spinous process with first and second lateral sides, the lamina hook comprising:

a single upper hook capable of being attached to the lamina under the spinous process on the cranial side of the vertebra, the upper hook having first and second upper arms extending from the upper hook for extending outwardly from the lamina, each upper arm defining an aperture;

a single lower hook capable of being attached to the lamina under the spinous process on the sacral side of the vertebra, the lower hook having first and second lower arms extending from the lamina for extending outwardly from the lamina on either side of the spinous process, each lower arm defining an aperture; and

a pair of shafts extending through the apertures of the arms of the upper and lower hooks on the lateral sides of the spinous process for attaching the upper hook to the lower hook.

10. A lamina hook as recited in claim 9 wherein the upper hook defines a triangle with an open center, the three sides of the triangle defined by the two upper arms and a third arm extending between the two upper arms.

11. A lamina hook as recited in claim 9 wherein the pair of shafts comprises a pair of bolts through the apertures of the lower hook and the upper hook, the bolts for being placed on either side of the spinous process.

12. A lamina hook as recited in claim 11 further comprising a pair of C-spacers that fit around the shafts between the upper and lower hooks for abutting against the upper and lower hooks.

13. A lamina hook as recited in claim 11 further comprising a pair of lock washers to prevent rotation of the bolts.

14. A lamina hook as recited in claim 9 further comprising means for attaching a spine rod.

15. A lamina hook as recited in claim 14 wherein the spine rod attaching means comprises a clamp.

16. A lamina hook as recited in claim 15 wherein the clamp is attached to at least one lower arm of the lower hook.

17. A lamina hook for attachment to a vertebra which includes a cranial side, a sacral side, a lamina and a spinous process with first and second lateral sides, the lamina hook comprising:

an upper hook for attachment to the lamina under the spinous process on the cranial side of the vertebra, the upper hook having first and second upper arms extending from the upper hook, outwardly from the lamina;

a lower hook for attachment to the lamina under the spinous process on the sacral side of the vertebra, the lower hook having first and second lower arms extending from the lower hook outwardly from the lamina; and

first and second means for attaching the upper hook to the lower hook, the first attaching means extending between the first arm of the upper hook and the first arm of the lower hook on the first lateral side of the spinous process and the second attaching means extending between the second arm of the upper hook and the second arm of the lower hook on the second lateral side of the spinous process.

18. A lamina hook as recited in claim 17 further comprising means for attaching a spine rod.

19. A lamina hook as recited in claim 18 wherein the spine rod attaching means comprises a clamp.

20. A lamina hook as recited in claim 19 wherein the clamp is attached to at least one of the arms of the upper and lower hook.

21. A lamina hook as recited in claim 17 further comprising a pair of clamps for attaching a pair of spine rods.

22. A lamina hook as recited in claim 21 wherein each clamp is attached to an arm of the upper hook.

23. A lamina hook as recited in claim 21 wherein each clamp is attached to an arm of the lower hook.

24. A lamina hook as recited in claim 17 wherein each arm of the upper hook and the lower hook defines an aperture and the first and second means for attaching the upper hook to the lower hook comprises a pair of bolts extending through the apertures of the first and second arms of the upper and lower hooks.

25. A lamina hook as recited in claim 24 further comprising a first clamp on the first arm of the upper hook for attaching a first spine rod and a second clamp on the second arm of the upper hook for attaching a second spine rod.

26. A lamina hook as recited in claim 24 further comprising a first clamp on the first arm of the lower hook for attaching a first spine rod and a second clamp on the second arm of the lower hook for attaching a second spine rod.

27. A lamina hook for attachment to a vertebra which includes a cranial side, a sacral side, a lamina and a spinous process with first and second lateral sides, the lamina hook comprising:

an upper hook capable of being attached to the lamina under the spinous process on the cranial side of the vertebra, the upper hook having first and second upper arms extending from the upper hook for extending outwardly from the lamina, each upper arm including an aperture;

a lower hook capable of being attached to the lamina under the spinous process on the sacral side of the vertebra, the lower hook having first and second lower arms extending from the lamina for extending outwardly from the lamina, each lower arm including an aperture;

a first shaft for extending through the apertures of the first arms of the upper and lower hooks on the first lateral side of the spinous process for attaching the upper hook to the lower hook; and

a second shaft for extending through the apertures of the second arms of the upper and lower hooks on the second lateral side of the spinous process for attaching the upper hook to the lower hook.

28. A lamina hook as recited in claim 27 wherein the first and second shafts comprise a pair of bolts.

29. A lamina hook as recited in claim 27 further comprising means for attaching a spine rod.

30. A lamina hook as recited in claim 29 wherein the spine rod attaching means comprises a clamp.

31. A lamina hook as recited in claim 30 wherein the clamp is attached to at least one arm of the upper and lower hooks.

32. A lamina hook as recited in claim 31 wherein the clamp comprises a saddle clamp.

33. A lamina hook as recited in claim 27 further comprising a pair of clamps for attaching a pair of spine rods.

34. A lamina hook as recited in claim 33 wherein each clamp is attached to an arm of the upper hook.

35. A lamina hook as recited in claim 33 wherein each clamp is attached to an arm of the lower hook.

36. A lamina hook as recited in claim 33 wherein the clamps comprise saddle clamps.