Bi-directional fixating transvertebral body screws and posterior cervical and lumbar interarticulating joint calibrated stapling devices for spinal fusion

Abstract

A self-drilling bone fusion screw apparatus is disclosed which includes at least first and second sliding boxes. A first screw member having a tapered end and a threaded body is disposed within the first sliding box, and a second screw member having a tapered end and a threaded body disposed within the second sliding box. An adjuster adjusts the height of the sliding boxes. The screw members are screwed into vertebral bodies in order to fuse the vertebral bodies together. A plurality of the self-drilling bone fusion screw apparatuses may be attached together and/or integrated via a plate or cage. Also disclosed is a cervical facet staple that includes a curved staple base and at least two prongs attached to the bottom surface of the curved staple base.

Claims

1. A universal, intervertebral combination internal screw guide and fixation apparatus configured to be inserted into a disc space between a first vertebral body and a second vertebral body and to provide fusion of the first vertebral body to the second vertebral body via biological bone fusion and screw fusion, the apparatus comprising: an intervertebral cage including: a top wall, a bottom wall, and two sidewalls defining an open space capable of receiving bone filling for the biological bone fusion; and an internal screw guide having an internal bore with an entry opening and an exit opening, and the entry opening of the internal bore is formed only in a top surface of the top wall and the exit opening is formed at least partially in a bottom surface of the top wall and at least partially in a side surface of the top wall, wherein the side surface of the top wall is patterned with a plurality of surface features to create a rough side surface, wherein at least some of the plurality of surface features are positioned on the side surface closer to the top surface of the top wall than the exit opening, wherein first and second slots are defined in the two sidewalls, wherein a threaded hole extends through the top wall in a direction substantially normal to the top surface of the top wall with a diameter of the threaded hole being smaller than a diameter of the internal screw guide, and wherein a rectangular indentation extends into at least part of the top wall and is oriented with at least one side of the rectangular indentation being substantially parallel to the side surface of the top wall; a first screw having a first screw head and a first threaded body that is sized and configured to be inserted through the internal screw guide; and a tool for manipulating and inserting the intervertebral cage into the disc space between the first vertebral body and the second vertebral body to provide fusion of the first vertebral body to the second vertebral body via biological bone fusion and screw fusion, the tool comprising: an elongate shaft; and a tool screw guide for controlling direction of the first screw when inserted into the internal screw guide of the intervertebral cage.

2. The apparatus of claim 1, wherein an internal surface of the internal screw guide extends continuously from the entry opening to the exit opening.

3. The apparatus of claim 1, wherein the internal screw guide extends through an entire depth of the top wall from the top surface to the bottom surface and exiting at least partially into the open space.

4. The apparatus of claim 1, wherein the internal screw guide permits only a predetermined angled trajectory of a screw member through the intervertebral cage.

5. The apparatus of claim 1, wherein the internal screw guide has a 25 degree angulation.

6. The apparatus of claim 1, wherein the top wall has a thickness extending from the top surface of the top wall to the bottom surface of the top wall in a direction of a depth of the intervertebral cage, a height of the intervertebral cage extending in a direction perpendicular to the depth, and wherein an axis of the internal screw guide extends to a greater extent in the direction of the depth of the intervertebral cage than in a direction of a height of the intervertebral cage in order to facilitate multi-level fusion of adjacent vertebral bodies with multiple intervertebral cages.

7. The apparatus of claim 1, wherein the top wall of the intervertebral cage has a thickness that is greater than a thickness of each of the sidewalls.

8. The apparatus of claim 1, wherein at least one of the two sidewalls includes a hole configured to allow placement of bone filling into the open space of the intervertebral cage for the biological bone fusion.

9. The apparatus of claim 1, wherein a surface of each of the two sidewalls includes a plurality of ridges.

10. The apparatus of claim 1, wherein the intervertebral cage is configured to receive a plate for securing a second intervertebral cage thereto.

11. The apparatus of claim 10, wherein the intervertebral cage comprises: a screw insert configured to receive the plate for securing the second intervertebral cage thereto.

12. The apparatus of claim 1, wherein the intervertebral cage is a cervical intervertebral cage configured to fit into a cervical disc space.

13. The apparatus of claim 1, wherein the intervertebral cage is a lumbar intervertebral cage configured to fit into a lumbar disc space.

14. The apparatus of claim 1, wherein the intervertebral cage is a posterior lumbar intervertebral cage configured to fit into a lumbar disc space.

15. The apparatus of claim 1, wherein the intervertebral cage capable of one of posterior lumbar intervertebral placement, anterior lumbar intervertebral placement, thoracic intervertebral placement, and anterior cervical intervertebral placement.

16. The apparatus of claim 1, wherein the intervertebral cage further comprises: a second internal screw guide having a second entry opening and a second exit opening, the second entry opening formed at least partially in the top surface of the top wall and the second exit opening formed at least partially in the bottom surface of the top wall and at least partially in a second side surface of the top wall.

17. The apparatus of claim 16, wherein each of the internal screw guide and the second internal screw guide is angled to orient a first screw member and a second screw bi-directionally in opposite directions.

18. The apparatus of claim 17, wherein the internal screw guide is configured to orient the first screw member rostrally and the second internal screw guide is configured to orient the second screw member caudally.

19. The apparatus of claim 16, wherein the internal screw guide and the second internal screw guide are at an angulation with respect to the top surface of the top wall.

20. The apparatus of claim 16, wherein each of the internal screw guide and the second internal screw guide permits only a 25 degree angulation of a first screw member and the second screw member.

21. The apparatus of claim 16, wherein the internal screw guide and the second internal screw guide are aligned along a longitudinal axis of the top wall of the intervertebral cage.

22. The apparatus of claim 16, wherein the internal screw guide and the second internal screw guide are symmetrically disposed on each side of a center point of the intervertebral cage along a longitudinal axis of the top wall of the intervertebral cage.

23. The apparatus of claim 16, wherein the internal screw guide and the second internal screw guide are offset in opposite directions with respect to a center line of a longitudinal extent of the top wall.

24. The apparatus of claim 23, wherein a part of the internal screw guide overlaps a part of the second internal screw guide along the longitudinal extent of the top wall.

25. The apparatus of claim 16, wherein the entry opening of the internal screw guide and the second entry opening of the second internal screw guide are arranged diagonally on the top surface of the top wall.

26. The apparatus of claim 16, wherein the top wall has four quadrants delineated by a first axis and a second axis each lying in a plane of the top wall, and the first axis is at a right angle with respect to the second axis, wherein the four quadrants include a first quadrant, a second quadrant, a third quadrant, and a fourth quadrant, wherein the first quadrant and the fourth quadrant are opposed to the second quadrant and the third quadrant with respect to the first axis, and the first quadrant and the second quadrant are opposed to the third quadrant and the fourth quadrant with respect to the second axis, wherein the first quadrant is diagonally opposed to the third quadrant, and the second quadrant is diagonally opposed to the fourth quadrant, and wherein a majority of an area of the entry opening of the internal screw guide is in the first quadrant and a majority of an area of the second entry opening of the second internal screw guide is in the third quadrant.

27. The apparatus of claim 16, wherein the top wall has four quadrants delineated by a first axis and a second axis each lying in a plane of the first wall, and the first axis is at a right angle with respect to the second axis, wherein the four quadrants include a first quadrant, a second quadrant, a third quadrant, and a fourth quadrant, wherein the first quadrant and the fourth quadrant are opposed to the second quadrant and the third quadrant with respect to the first axis, and the first quadrant and the second quadrant are opposed to the third quadrant and the fourth quadrant with respect to the second axis, wherein the first quadrant is diagonally opposed to the third quadrant, and the second quadrant is diagonally opposed to the fourth quadrant, and wherein a center of the entry opening of the internal screw guide is in the first quadrant and a center of the second entry opening of the second internal screw guide is in the third quadrant.

28. The apparatus of claim 16, wherein the top wall includes a first corner and a second corner, the first corner being arranged at an opposite side of the top wall and an opposite end of the top wall with respect to the second corner, and wherein the internal screw guide and the second internal screw guide are diagonally arranged along a direction extending from the first corner of the top wall to the second corner of the top wall.

29. The apparatus of claim 16, wherein the intervertebral cage further comprises: a third internal screw guide having a third entry opening and a third exit opening, the third entry opening formed at least partially in the top surface of the top wall and the third exit opening formed at least partially in the bottom surface of the top wall and at least partially in the side surface of the top wall.

30. The apparatus of claim 29, wherein the intervertebral cage further comprises: a fourth internal screw guide having a fourth entry opening and a fourth exit opening, the fourth entry opening formed at least partially in the top surface of the top wall and the fourth exit opening formed at least partially in the bottom surface of the top wall and at least partially in the second side surface of the top wall.

31. The apparatus of claim 30, wherein the internal screw guide and the fourth internal screw guide are oriented rostrally and the second internal screw guide and the third internal screw guide are oriented caudally.

32. The apparatus of claim 30, wherein the second internal screw guide and the third internal screw guide are disposed between the internal screw guide and the fourth internal screw guide along a longitudinal length of the top wall of the intervertebral cage.

33. The apparatus of claim 30, wherein each of the internal screw guide, the second internal screw guide, the third internal screw guide, and the fourth internal screw guide has a 25 degree angulation.

34. The apparatus of claim 1, further comprising: a second intervertebral cage including: a top wall, a bottom wall, and two sidewalls defining an open space capable of receiving bone filling for biological bone fusion, and an internal screw guide having an entry opening and an exit opening, the entry opening of the second intervertebral cage formed at least partially in a top surface of the top wall of the second intervertebral cage and the exit opening formed at least partially in a bottom surface of the top wall of the second intervertebral cage and at least partially in a side surface of the top wall of the second intervertebral cage; and an attachment member coupling the intervertebral cage to the second intervertebral cage.

35. The apparatus of claim 34, wherein the attachment member includes a supplemental cage defining one or more open spaces capable of receiving the intervertebral cage and the second intervertebral cage, and wherein the intervertebral cage and the second intervertebral cage are secured to the supplemental cage.

36. The apparatus of claim 34, wherein the attachment member includes a plate.

37. The apparatus of claim 16, wherein the intervertebral cage is devoid of any other internal screw guides other than the first internal screw guide and a second internal screw guide.

38. The apparatus of claim 1, wherein the exit opening is formed at least partially in a surface of one of the two sidewalls.

39. The apparatus of claim 35, wherein the supplemental cage surrounds a perimeter of the intervertebral cage and the second intervertebral cage.

40. The apparatus of claim 1, wherein the internal screw guide includes: a counterbore formed at least partially in the top surface of the top wall for accommodating a screw head of a screw member; and an internal bore configured to continuously guide a body of the screw member through the internal screw guide into the open space and into the first vertebral body, wherein the internal bore includes a bore entry opening formed in a lower surface of the counterbore, the bore entry opening formed entirely between all edges of the top surface of the top wall when viewed from a direction perpendicular to a plane of the top surface, and a bore exit opening formed partially in the bottom surface of the top wall and partially in the side surface of the top wall.

41. The apparatus of claim 40, wherein the internal bore is coaxial with the counterbore.

42. A zero-profile, intervertebral cage sized and configured to be inserted into a disc space between adjacent vertebral bodies and to provide fusion of the adjacent vertebral bodies via biological bone fusion and screw fusion, the intervertebral cage comprising: a top wall; a bottom wall opposite the top wall; a first sidewall; a second sidewall opposite the first sidewall, each of the first sidewall and the second sidewall having a surface configured to contact one of the adjacent vertebral bodies when the intervertebral cage is inserted into the disc space, wherein at least the first sidewall and the second sidewall bound an open space capable of receiving bone filling for the biological bone fusion, wherein the top wall includes a top surface and a bottom surface opposite the top surface, the top surface configured to have a zero-profile with respect to the adjacent vertebral bodies when the intervertebral cage is inserted into the disc space, and the bottom surface facing the open space; and an internal screw trajectory guide for guiding a trajectory of a screw through the intervertebral cage, the internal screw trajectory guide having an entry opening and an exit opening, the entry opening formed at least partially in the top surface of the top wall, and the exit opening formed at least partially in a bottom surface of the top wall and at least partially in a side surface of the top wall, wherein a width of the top surface of the top wall is greater than a width of the bottom surface of the top wall, and wherein a perimeter of the entry opening does not extend beyond the width of the top surface of the top wall and a perimeter of the exit opening extends beyond the width of the bottom surface of the top wall.

43. The apparatus of claim 42, wherein the entry opening of the internal screw trajectory guide is formed entirely between all edges of the top surface of the top wall when viewed from a direction perpendicular to a plane of the top surface.

44. An intervertebral combination internal screw guide and fixation apparatus configured to be inserted into a disc space between a first vertebral body and a second vertebral body and to provide fusion of the first vertebral body to the second vertebral body via biological bone fusion and screw fusion, the apparatus comprising: an intervertebral spacer including a top wall, a bottom wall, and first and second sidewalls, wherein the intervertebral spacer defines: an open space between the top, bottom, first, and second sidewalls capable of receiving bone filling for biological bone fusion, a first slot on a first outer side of the first sidewall, a second slot on a second outer side of the second sidewall of the two sidewalls, wherein the second slot is positioned opposite of the first slot, wherein the first slot is positioned along a first centerline axis that bisects the first side wall and wherein the second slot is positioned along a second centerline axis that bisects the second side wall, an indentation in the top surface of the top wall, a first internal screw guide having a first entry opening and a first exit opening, the first entry opening of the first internal screw guide formed at least partially in a top surface of the top wall and the first exit opening formed at least partially in a bottom surface of the top wall and at least partially in a first side surface of the top wall, a second internal screw guide having a second entry opening and a second exit opening, the second entry opening of the second internal screw guide formed at least partially in the top surface of the top wall and the second exit opening formed at least partially in the bottom surface of the top wall and at least partially in a second side surface of the top wall so as to extend in a direction different than that of the first internal screw guide, and a plurality of surface features patterned on the first and second side surfaces of the top wall near the top surface of the top wall, wherein at least some of the plurality of surface features are positioned on the first side surface closer to the top surface of the top wall than is the first exit opening and at least some of the plurality of surface features are positioned on the second side surface closer to the top surface than is the second exit opening, a first screw having a first screw head and a first threaded body that is sized and configured to be inserted through the first internal screw guide; and a second screw having a second screw head and a second threaded body that is sized and configured to be inserted through the second internal screw guide; a tool for manipulating and inserting the intervertebral spacer into the disc space between the first vertebral body and the second vertebral body to provide fusion of the first vertebral body to the second vertebral body via biological bone fusion and screw fusion, the tool comprising: an elongate shaft; first and second gripper prongs positioned such that the first gripper prong engages the first slot of the intervertebral spacer and the second gripper prong engages the second slot of the intervertebral spacer when the tool engages the intervertebral spacer; and a tool screw guide for controlling direction of the first screw and the second screw when inserted into the first internal screw guide and the second internal screw guide of the intervertebral spacer, wherein the tool screw guide is positioned between the plurality of prongs with distal ends of the prongs extending distally past the tool screw guide.

45. The apparatus of claim 44, wherein the intervertebral spacer further defines: a first circular side hole extending into the first outer surface of the first sidewall; and a second circular side hole extending into the second outer surface of the second sidewall, wherein the second circular side hole is positioned opposite of the first circular side hole, wherein the first slot and the first circular side hole are both positioned along the first centerline axis that bisects the first side wall and wherein the second slot and the second circular side hole are both positioned along the second centerline axis that bisects the second side wall.

46. The apparatus of claim 44, wherein the top wall is continuous with the first and second sidewalls.

47. The apparatus of claim 44, wherein the open space extends from an inner surface of the first sidewall to an inner surface of the second sidewall and extends from an inner surface of the top wall to an inner surface of the bottom wall.

48. The apparatus of claim 44, wherein the plurality of surface features are patterned all the way to the top surface of the top wall such that at least one or more of the surface features are positioned on the first side surface of the top wall adjacent to the top surface of the top wall.

49. The apparatus of claim 44, wherein the open space extends continuously from the first sidewall to the second sidewall.

50. The apparatus of claim 44, and further comprising means for attaching to and covering at least a portion of the top surface of the top wall at the indentation of the top surface of the top wall.

51. The apparatus of claim 44, wherein the tool comprises means for attaching to the intervertebral cage.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIGS. 1A-D illustrate the Lumbar intervertebral screw box with one lateral oriented BDFT screw and one medially oriented BDFT screw (Embodiment IA) in sagittal-oblique (FIG. 1A), superior perspective (FIG. 1B), inferior perspective (FIG. 1C) and exploded (FIG. 1D) views.

(2) FIG. 1E illustrates the lumbar intervertebral expandable screw box with two lateral oriented BDFT screws (Embodiment IB; sagittal-oblique view).

(3) FIGS. 2A-C illustrate the Lumbar intervertebral non-expandable screw box with two BDFT screws (Embodiment II) in lateral (FIG. 2A), oblique (FIG. 2B), and superior perspective (FIG. 2C) views.

(4) FIG. 3 illustrates a superior oblique perspective view of left and right lumbar intervertebral non-expandable screw boxes with one BDFT screw (Embodiment III).

(5) FIGS. 4A-B illustrate the horizontal intervertebral zero-profile mini-plate prior to insertion (FIG. 4A), and after insertion (FIG. 4B) into two non-expandable lumbar intervertebral screw boxes with two BDFT screws.

(6) FIG. 4C illustrates two non-expandable lumbar intervertebral screw boxes with two screws within a large circumferential cage for anterior placement into the lumbar spine

(7) FIGS. 5A-C illustrate t positioning tool/screw guide/box expander in oblique perspective (FIG. 5A), lateral (FIG. 5B), and exploded (FIG. 5C) views.

(8) FIG. 5D illustrates a superior oblique perspective view of the positioning tool/drill guide/box expander component.

(9) FIGS. E-G illustrate the sequential steps (I-III) of the positioning tool/screw guide/box expander assembly. Step I (FIG. 5E), step II (FIG. 5F), and step III (FIG. 5G).

(10) FIGS. 5H-I illustrate the positioning tool for impaction and placement of the non-expandable screw box with two transvertebral screws. Embodiment I has a rectangular positioning handle (FIG. 5H), and embodiment II has a circular positioning handle (FIG. 5I)

(11) FIGS. 6A-B illustrate the insertion of expandable Lumbar bi-directional screw box with two BDFT screws into the Lumbar spine in oblique (FIG. 6A) and lateral (FIG. 6B) views.

(12) FIGS. 7A-B illustrate the cervical facet staple (Embodiment I) in lateral (FIG. 7A) and oblique (FIG. 7B) views.

(13) FIGS. 8A-C illustrate the cervical facet staple (Embodiment II) in oblique (FIG. 8A), superior perspective (FIG. 8B) and inferior-oblique (FIG. 8C) views.

(14) FIG. 9A illustrates the two-pronged cervical facet staple inserter/impactor (Embodiment I).

(15) FIG. 9B illustrates the two-pronged cervical facet staple inserter/impactor inserted into the staple (Embodiment I).

(16) FIG. 10A illustrates the four pronged cervical facet staple impactor (Embodiment II).

(17) FIG. 10B illustrates the four pronged cervical facet staple impactor inserted into the cervical facet staple (Embodiment II).

(18) FIG. 10C illustrates an inferior-oblique perspective view of the four-pronged cervical facet staple impactor (Embodiment II).

(19) FIG. 11A illustrates placement of two-pronged cervical facet staples in a three-dimensional cervical spine.

(20) FIG. 11B illustrates placement of four-pronged cervical facet staples in a three-dimensional cervical spine.

(21) FIG. 11C illustrates modular placement of two and four pronged cervical facet staples in a three-dimensional cervical spine to achieve differing calibrated degrees of flexibility.

(22) FIGS. 12 A-B illustrate the Lumbar facet joint staple with a calibrated ratcheting mechanism in opened (Figure A) and closed (Figure B) positions.

DETAILED DESCRIPTION OF THE INVENTION

(23) 1. The Medical Device

(24) Referring to FIGS. 1-6, the above described problem can be solved in the thoracic and lumbar spine by insertion into the denuded intervertebral disc space multiple embodiments of screw box constructs with BDFT screws.

(25) FIGS. 1A-D illustrate three-dimensional views of the Lumbar intervertebral expandable screw box 100 with two BDFT screws 101, 102; one lateral and one medially oriented (Embodiment IA). FIG. 1E illustrates a sagittal-oblique view of the lumbar intervertebral expandable screw box 120 with two lateral oriented BDFT screws 121, 122 (Embodiment IB).

(26) The expandable box 100 consists of top and bottom triangular sliding bases 103, 104 (FIG. 1-D). The superior and inferior segments of the height/depth adjusting screw 105 are integrated and connected to the two separate top and bottom triangular bases 103, 104, respectively. By turning this adjusting screw 105 back and forth i.e. clock-wise, and counter clockwise, the sliding rails 106 of the top triangular base 103 (FIG. 1D) slide up and down the rail inserts 107 on the bottom triangular base 104 (FIG. 1D). This action will simultaneously alter the intervertebral height and depth of the screw box 100 allowing individualized custom fitting of the screw box 100 conforming to the dimensions of the disc space.

(27) Transvertebral screw 101 penetrates the top base 103, and transvertebral screw 102 traverses the bottom base 104 of the screw box 100. The two screws 101, 102 traverse the screw box 100 in opposing directions, bi-directionally (whether they are lateral or medially oriented). The external edges of the triangular bases 103, 104 in contact with vertebral body surfaces include ridges 107. This facilitates the screw box's 100 incorporation into and fusion with the superior and inferior vertebral bodies (FIGS. 1A-E). Both top and bottom screw box bases 103, 104 are perforated with holes 108 to allow bone placement for fusion. The entire construct, furthermore, is hollow to allow bone filling. Hence this device functions as both an intervertebral bone fusion spacer and bi-directional transvertebral screw fusion device.

(28) FIGS. 2A-C illustrate three-dimensional views of the Lumbar intervertebral non-expandable screw box 200 with two BDFT screws 201, 202 (Embodiment II). Screws 201 and 202 perforate and orient in opposing, superior and inferior directions. There are holes 208 and hollow spaces allowing packaging with bone. There are also holes which allow the traversal of screws. The superior and inferior edges include ridges 207 to facilitate integration and fusion with superior and inferior vertebral bodies. The expandable screw box 200 may include a screw insert 209 to attach a horizontal mini-plate (not shown). The self-contained internalized drill guides are at a 25 degree angle. The screw boxes can be designed with the internalized drill guides with different angles and/or different positions within the box.

(29) FIG. 3 illustrates a three-dimensional view of left and right lumbar intervertebral non-expandable screw boxes 300a, 300b with one BDFT screw 301 or 302 (Embodiment III). It is roughly half the width of Embodiments I and II. Screw 301 is inserted into screw box 300a (left) and screw 302 is inserted into screw box 300b (right). There are holes 308 and hollow spaces allowing packing of bone to achieve biological fusion. The combined effect of one superior oriented and one inferior oriented screw fuses the superior and inferior vertebral bodies with small constructs. This also enables placement of larger dimension screws compared to embodiments I and II.

(30) FIGS. 4A and B illustrate three-dimensional views of the horizontal intervertebral zero profile mini-plate 400 with two non-expandable lumbar intervertebral screw boxes 300a, 300b housing two BDFT screws 301, 302. FIG. 4A illustrates the perforations 401 within the plate 400 through which small plate securing screws 310 will be inserted to connect it to the built-in screw holes of the screw box 300a, 300b (FIG. 4B). The horizontal mini-plate 400 together with the top surfaces of left and right screw boxes 300a, 300b provide a physical barrier between the underlying bone placed beneath it (not illustrated), and the thecal sac and nerve roots above it (not illustrated).

(31) FIG. 4C illustrates two screw boxes 300c, 300d within a circumferential cage 420 (2 in 1) construct which is designed for anterior placement into the lumbar spine. There are slots 308a, 308b for bone graft placement, both outside and inside the boxes. The circumferential cage 420 has perforations 401a for the placement of transvertebral screws (not shown).

(32) FIGS. 5A-C illustrate three-dimensional views of the external drill/screw guide-box expander 500 which assists in screw trajectory and box expansion (embodiments IA-B). For embodiments II and III, the same instrument is utilized; however, an expanding Allen key component is not used.

(33) The key components of this device include an Allen key 501, a spring 502, a handle 503, a griper 504 and a screw guide 505. The Allen key 501 when inserted in the insertion 514 and turned, turns the screw adjuster (FIG. 5C) which in turn regulates top and bottom triangular screw box base sliding, and hence box 200 width and depth. The griper 504 has griper prongs 506 which insert into grooves of the screw guide 505 and the screw box 200 (FIGS. 5A-D) thus perfectly aligning them.

(34) FIG. 5D illustrates a superior oblique view of the screw guide 505 demonstrating insertions 509 for griper prong 506, built-in trajectory guides 511, 512 for insertions of screws 101 and 102, and the Allen key 501.

(35) FIGS. 5E-G illustrate three-dimensional views of the sequential steps necessary for the external guide assembly. FIG. 5E illustrates the insertion of the Allen key 501 into the handle 503. FIG. 5F illustrates the insertion of the handle 503 through the spring 502 and griper 504. FIG. 5G illustrates insertion of the griper 504 into the screw guide 505.

(36) FIGS. 5H-I illustrate three-dimensional views of a positioning tool 500a for impaction and placement of two transvertebral screws 201, 202 in the non-expandable screw box 200. The driver assembly 550 consists of a screw driver 551, a flexible shaft 552 and a square recess bit 553. This facilitates turning the screws 201, 202 into the bone. The flexible shaft 552 facilitates the avoidance of spinous processes which might hinder the screw driving if the shaft 552 were straight. The positioning tool 500a can have a rectangular handle, Embodiment I (FIG. 5H), or a circular handle, Embodiment II (FIG. 5I). This serves to position the screw box within the intervertebral space, and screws 201, 202 within the screw box. Once positioned, the screw box can be impacted by tapping the handle with a mallet (not shown). The positioning tool's 500a griper handle inserts into the screw guide and the box, which maintains alignment.

(37) FIG. 6A illustrates a three-dimensional view of insertion of the construct (Embodiment I) into the lumbar intervertebral disc space.

(38) FIG. 6B illustrates a three dimensional lateral view of insertion of the construct (Embodiment I) into the disc space with short screws. Placement with longer screws would capture more bone.

(39) FIGS. 7A and B illustrate three-dimensional views of the two-pronged cervical facet staple 700 (Embodiment I). There is a staple base 701 which is contoured to align with the curved surface of the cervical facet joints. There is a superior impactor threaded insert 702. An impactor can be screwed into this insert 702 and then impacted with a mallet. The two spikes 703, 704 perforate the inferior and superior facets of the superior and inferior vertebral bodies hence leading to cervical facet joint fusion. The spikes can be designed with ridges and/or fishhooks to facilitate irreversible extraction.

(40) FIGS. 8A-C illustrate three-dimensional views of the four-pronged cervical facet staple 800 (Embodiment II). Likewise it has a staple base 805 contoured specifically for the surface of the facet joint. It also has an impactor insert 806. The insertion of a device with four prongs 801-804 instead of two prongs further limits the degrees of motion of the joint hence making the fusion more rigid.

(41) FIGS. 9A-B illustrate a three-dimensional view of the two-pronged cervical staple impactor 900. It has a handle 901, a stem 902, and a screw insert 903 which can be screwed into the threaded staple insert. The impactor has two wings 904 which keep the staple base edges in place facilitating staple impaction. The handle 901 of the impactor 900 is broad in order to allow impaction by a mallet.

(42) FIGS. 10A-C illustrate three-dimensional views of the four-pronged cervical staple impactor 1000 (Embodiment II). It has the same features as the two-pronged impactor 900, except its wings 1004 are broader accommodating the broader staple base. The impactor 1000 also includes a handle 1001, a stem 1002, and an impact screw 1003.

(43) FIG. 11A illustrates a three-dimensional view of placement of the two pronged cervical facet staple 700 into a cervical spine model having vertebral body 1103 and lamina 1104. One staple 700 is perched on the joint 1101 prior to impaction. The other staple 700 is impacted.

(44) FIG. 11B illustrates a three-dimensional view of placement of the four pronged cervical facet staple 800 into a cervical spine pre and post impaction.

(45) FIG. 11C illustrates the concept of modularity and incremental diminution of movement of the joint by the modular placement of different combinations and permutations of varying numbers of two and four pronged cervical facet staples 700, 800. If one wishes to have the most flexible (least rigid) fusion, one would place a unilateral two pronged staple 700. One can increase i.e. calibrate increasing degrees of rigidity by increasing the number of prongs penetrating the facet joints bilaterally. In FIG. 11C each facet joint is fused using a total number of six prongs. One side this is accomplished by using three two pronged staples 700, and on the other side using one four pronged staple 800 and one two pronged staple 700. These two embodiments can be mixed and matched unilaterally or bilaterally to vary the degree of rigidity and conversely flexibility of fusion. The most flexible fusion at one level would be accomplished by one staple 700 (2 prongs). The highest level of rigidity would be achieved by placing two four pronged staples 800 on both sides totaling sixteen prongs. Intermediate degrees of relative joint motion can be modulated by insertion into the cervical facet joints staples in two-four prong increments from 2-16. Each additional prong further limits the degree of facet joint motion hence increasing rigidity, and conversely decreasing flexibility. Thus the novel modular use of these embodiments heralds an era of flexible cervical spine fusion.

(46) FIGS. 12A-B illustrate a lumbar facet joint staple 1200 in open and closed positions and having staple prongs 1203. This lumbar facet staple has been thoroughly described in our previous co-pending patent application Ser. No. 11/536,815, filed on Sep. 29, 2006, and Ser. No. 11/208,644, filed on Aug. 23, 2005, the relevant portion of each of which is hereby incorporated by reference hereinafter. The new improvement of this device includes a ratchet 1201. The staple 1200 can be incrementally closed with increased ratcheting over increasing number of spurs 1202. This achieves increasing calibrated levels of lumbar facet joint fusion, and conversely diminishing joint flexibility. This new designs further enhances the capacity to achieve flexible fusions in the lumbar spine.

(47) 2. The Surgical Method

(48) Exemplary surgical steps for practicing one or more of the foregoing embodiments will now be described.

(49) The posterior lumbar spine implantation of all the screw box 100, 200, 300 embodiments, with BDFT screws, and horizontal mini-plate 400 can be implanted via previously described posterior lumbar interbody fusion (PLIF) or posterior transforaminal lumbar interbody fusion (TLIF) procedures. The procedures can be performed open, microscopic, closed tubular or endoscopic. Fluoroscopic guidance can be used with any of these procedures.

(50) After adequate induction of anesthesia, the patient is placed in the prone position. A midline incision is made for a PLIF procedure, and one or two parallel paramedian incisions or a midline incision is made for the TLIF procedure. For the PLIF, a unilateral or bilateral facet sparing hemi-laminotomy is created to introduce screw box 100, 200, 300 embodiments I-III into the disc space, after it is adequately prepared.

(51) For the TLIF procedure, after unilateral or bilateral dissection and drilling of the inferior articulating surface and the medial superior articulating facet the far lateral disc space is entered and a circumferential discectomy is performed. The disc space is prepared and the endplates exposed.

(52) Then one screw box 100, 200, 300 of either embodiments I-III is placed on either right, left or both sides. Then another screw box of embodiments 100, 200, 300 I-III is placed on the contralateral side. For embodiment I the external screw guide 505/box expander is attached to the screw box (FIGS. 5A-H). First the Allen key 501 is screwed until the box conforms perfectly to the height and depth of the space. Then a pilot hole can be drilled or an awl can start a pilot hole in the vertebral bodies. Then a transvertebral screw is screwed into the vertebral body via the built-in box screw guides 505. For difficult angles, an angled screw driver can be employed.

(53) For embodiments II-III the same method is used for placing screws, except the Allen key 501 is not utilized in the absence of plate expansion.

(54) If bilateral constructs have been inserted, bone is packed into the intervertebral space, as well as within the device. Then the horizontal intervertebral zero profile mini-plate 400 is slid beneath the thecal sac and is secured to both left and right screw boxes with small mini-plate screws 210 (FIGS. 4A-B). This prevents bone intrusion into the thecal sac and hence possible nerve root compression.

(55) FIGS. 6A and B illustrate the process of insertion and final placement of the construct into the lumbar spine. The mini-plates 400 can come in different horizontal lengths and widths to accommodate different intra and inter-patient disc space diameters. The BDFT screws can come in different widths, lengths and thread designs.

(56) The anterior thoracic and lumbar spine implantation of one, two or three screw box constructs 100, 200, 300 and BDFT screws can be performed in a similar manner to the posterior application. Likewise, a horizontal mini-plate 400 can be used to cap two or three screw box constructs 100, 200, 300 (one placed midline deeply, one placed left and one placed right, forming a triangulation). Alternatively two screw box constructs may be placed into a circumferential ring for anterior placement. Anterior placement of these devices can be performed into the L4/5 and L5/S1 spaces on the supine anesthetized patient via previously described open microscopic or endoscopic techniques. Once the disc space is exposed and discectomy and space preparation are performed, placement of one, two or three screw box embodiments 100, 200, 300 (I-III) or a 2 in I construct can be placed. The screw placement is facilitated by the internal screw guides, and different positioning tools ((FIG. 5). A right angled screw driver and/or ratchet could alternatively be employed A capping mini-plate 400 may be applied if desirable. The mechanism of screw placement and mini-plate 400 attachment are identical to what was described above.

(57) The posterior placement of screw box constructs 100, 200, 300 alone or combined with horizontal mini-plates 400 into the thoracic spine can be performed via previously described transpedicular approaches; open or endoscopic. The anterior placement into the thoracic spine can be accomplished via a trans-thoracic approach. Once the disc space is exposed via either approach, any combination of the above mention Embodiments (I-III) can be inserted. Engagement of the devices is identical to what was mentioned above.

(58) For posterior placement of cervical facet staple 700, 800 embodiments, after adequate induction of anesthesia the patient is flipped prone and his head and neck secured. A single midline or two para-median incisions are made for unilateral or bilateral or multilevel placement of staples. Ultimately the facet joint is exposed. Alternatively and preferably this can be performed percutaneously under fluoroscopic guidance with intravenous sedation. The staple 700, 800 (Embodiments I or II) is loaded into the impactor 900, 1000. The staple 700, 800 is placed on the two articulating cervical facets, and then impacted into the joint. To achieve modular calibrated fusion different combinations and permutations of cervical facet stales can be inserted ranging from a single unilateral two pronged staple providing a high degree of flexibility to a total of four bilaterally placed four pronged staples 800 (16 prongs) leading to the highest degree of rigidity. Additional bone may or may not be placed in its vicinity to facilitate permanent and solid fusion. This procedure can be performed open, closed, percutaneously, tubulary, endoscopically or microscopically. FIGS. 11A-C illustrates placement of the staples 700, 800 in the cervical spine.

(59) We have previously described surgical placement of the lumbar facet joint staple in our two co-pending patents. The surgical procedure for this device is identical to that which has been previously mentioned.

(60) The present inventions may provide effective and safe techniques that overcome the problems associated with current transpedicular based cervical, thoracic and lumbar fusion technology, and for many degenerative stable and unstable spine disease. These inventions could replace much pedicle screw-based instrumentation in many but not all degenerative spine conditions.

(61) The speed and simplicity of placement of cervical and lumbar facet staples, and placement of Lumbar screw box-BDFT constructs far exceeds that of current pedicle screw technology. Furthermore, these devices have markedly significantly decreased risk of misguided screw placement, and hence decreased risk of neural and vascular injury, and blood loss. In the lumbar spine BDFT screw constructs and facet staples could be applied modularly in different combinations to achieve different degrees of rigidity (flexibility). Patients having these devices would have decreased recovery and back to work time. These devices most likely lead to similar if not equal fusion with significantly less morbidity, and hence overall make them a major advance in the evolution of spinal instrumented technology leading to advances in the care of the spinal patient.

(62) Another major novelty and advance is the introduction of simple and safe modular calibrated cervical flexible fusion. To our knowledge neither a similar device nor a similar mathematical concept of modular joint flexibility/fusion calibration has been postulated for the cervical spine or for any other articulating joint.

(63) To our knowledge there have not been any previously described similar posterior lumbar and thoracic combined spacer and screw constructs. These devices can similarly be modified to stabilize bone fractures throughout the entire body. To our knowledge the description of zero to subzero profile anterior or posterior horizontal spinal plates which traverse the diameter of the disc space has not been previously described.