Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUSRE39035 E1
Publication typeGrant
Application numberUS 08/988,331
Publication date21 Mar 2006
Filing date11 Dec 1997
Priority date18 Nov 1994
Also published asUS5474551
Publication number08988331, 988331, US RE39035 E1, US RE39035E1, US-E1-RE39035, USRE39035 E1, USRE39035E1
InventorsCharles A. Finn, Scott Sherman
Original AssigneeHowmedica Osteonics Corp.
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Universal coupler for spinal fixation
US RE39035 E1
Abstract
A spinal rod coupler assembly providing four degrees of freedom for connecting a spinal rod to a vertebrae of a patient which includes a tubular coupler member, an eyebolt, an insert and a set screw. The coupler member has a longitudinal bore, a central axis, and an end portion that is open ended and internally threaded and a second end portion that is closed. A plurality of openings in the tubular coupler member that includes a first pair of openings intersecting the central axis of the bore at generally right angles and a second pair of openings intersecting the central axis of the bore at generally right angles. The first and second pairs of openings being perpendicular to each other. The first pair of openings are sized and shaped to receive a spinal rod. The eyebolt has a shank portion and an eye portion, with the shank portion being insertable through the second pair of openings of the coupler body. The eye portion has an opening sized and shaped to mate with a selected bone bolt or bone screw. The insert fits within the bore and has opposed, arc-shaped end portions with recesses for engaging the spinal rod and eyebolt member. The set screw threadably engages the internally threaded end portion of the bore and tightens the assembly of the rod, insert, and eyebolt within the coupler member.
Images(7)
Previous page
Next page
Claims(47)
1. A spinal rod coupler assembly providing four degrees of freedom for connecting a spinal rod to a vertebrae of a patient, comprising:
a) a tubular coupler member having a longitudinal bore surrounded by a wall, the bore having a central axis and first and second end portions, the first end portion being open ended and internally threaded, the second end portion being closed;
b) a plurality of openings through the wall of the tubular coupler member, each of the openings communicating with the bore;
c) the plurality of openings including a first pair of openings aligning along a first line that intersects the central axis of the bore at generally right angles, and a second pair of openings aligning along a second line that intersects the central axis of the bore at generally right angles, the first and second lines being generally perpendicular to each other and spaced apart so that the periphery of the first pair of openings is spaced longitudinally from the periphery of the second pair of openings;
d) the first pair of openings sized and shaped for receiving a spinal rod having a longitudinal axis, which can be aligned with the first line of the first pair of openings of the coupler body;
e) an eyebolt having a shank portion with a central axis and an eye portion, the shank portion being insertable through the second pair of openings of the coupler body, aligning the central axis of the shank with the second line of the second pair of openings, the eye portion having an opening sized and shaped to mate with a selected fastener;
f) an insert that fits within the bore, the insert having an outer surface that generally conforms to the shape of the bore, the insert having opposed, arc-shaped end portions with recesses for engaging the spinal rod the eyebolt shank portion;
g) a set screw that threadably engages the internally threaded end portion of the bore so that the set screw tightens the assembly of the rod, insert, and eyebolt within the coupler member;
h) whereby the coupler assembly provides for movement along four degrees of freedom which include a movement along and a rotation about the longitudinal axis of the spinal rod, and a movement along and a rotation about the central axis of the eyebolt shank when the assembly is being implanted in a patient.
2. The coupler assembly of claim 1, wherein the eye portion of the eyebolt has an upper and a lower surface with the eye portion opening having a spherically shaped surface on the upper and lower surface of the eye portion.
3. The coupler assembly of claim 1, wherein the shank portion of the eyebolt has an outer surface with knurling on a portion of the outer surface.
4. The coupler assembly of claim 1, wherein the shank portion of the eyebolt includes a shank end with a recess so as to allow slight flanging of the shank end after the shank portion is inserted through the second pair of openings in the coupler body.
5. The coupler assembly of claim 1, wherein the tubular coupler member includes an upper portion and a lower portion with the first pair of openings positioned in the upper portion and the second pair of openings positioned in the lower portion.
6. The coupler assembly of claim 5, wherein the upper portion of the tubular coupler member has a larger diameter in relation to the lower portion of the tubular coupler member.
7. The coupler assembly of claim 1, wherein the set screw has an upper surface and a lower surface, the lower surface being generally conical in shape and the upper surface being generally flat with a tool receptive socket for receiving a tool designed to thread the set screw into the threaded portion of the bore.
8. A spinal prosthesis providing four degrees of freedom, comprising:
a) an elongated spinal rod having a central longitudinal axis;
b) a tubular coupler member having a longitudinal bore surrounded by a wall, the bore having a central axis and first and second end portions, the first end portion being open ended and internally threaded, the second end portion being closed;
c) a plurality of openings through the wall of the tubular coupler member, each of the openings communicating with the bore;
d) the plurality of openings including a first pair of openings aligning along a first line that intersects the central axis of the bore at generally right angles, and a second pair of openings aligning along a second line that intersects the central axis of the bore at generally right angles, the first and second lines being generally perpendicular to each other and spaced apart so that the periphery of the first pair of openings is spaced longitudinally from the periphery of the second pair of openings;
e) the first pair of openings sized and shaped to receive a spinal rod having a longitudinal axis with the rod being insertable through the first pair of openings, aligning the rod's longitudinal axis with the first line of the first pair of openings of the coupler body;
f) an eyebolt having a shank portion with a central axis and an eye portion, the shank portion being insertable through the second pair of openings of the coupler body, aligning the central axis of the shank with the second line of the second pair of openings, the eye portion having an opening sized and shaped to mate with a selected fastener;
g) an insert that fits within the bore, the insert having an outer surface that generally conforms to the shape of the bore, the insert having opposed, shaped end portions with recesses for engaging the spinal rod and the eyebolt shank portion;
h) a set screw that threadably engages the internally threaded end portion of the bore so that the set screw tightens the assembly of the rod, insert, and eyebolt within the coupler member;
i) the bone fastener for anchoring the coupler assembly to a patient's vertebrae, the bone bolt having a first threaded portion configured to be surgically implantable into a patient's bone tissue and a second portion having surfaces for engaging the eyebolt opening;
j) whereby the assembled spinal prosthesis provides for movement along four degrees of freedom which include a movement along and a rotation about the longitudinal axis of the spinal rod, and a movement along and a rotation about the central axis of the eyebolt shank when implanted in a patient.
9. The coupler assembly of claim 8, wherein the eyebolt has an upper and a lower surface with the eyebolt opening having a spherically shaped surface on the upper and lower surface of the eyebolt that cooperates with the surface of the bone fastener.
10. The coupler assembly of claim 8, wherein the shank portion of the eyebolt has an outer surface with knurling on a portion of the outer surface.
11. The coupler assembly of claim 8, wherein the shank portion of the eyebolt includes a shank end with a recess so as to allow slight flanging of the shank end after the shank portion is inserted through the second pair of openings in the coupler body.
12. The coupler assembly of claim 8, wherein the tubular coupler member includes an upper portion and a lower portion with the first pair of openings positioned in the upper portion and the second pair of openings positioned in the lower portion.
13. The coupler assembly of claim 12, wherein the upper portion of the tubular coupler member has a larger diameter in relation to the lower portion of the tubular coupler member.
14. The coupler assembly of claim 8, wherein the set screw has an upper surface and a lower surface, the lower surface being generally conical in shape and the upper surface being generally flat with a tool receptive socket for receiving a tool designed to thread the set screw into the threaded portion of the bore.
15. The coupler assembly of claim 8, wherein the bone fastener further includes a central non-threaded portion having a load transfer surface and an second threaded portion for threadably receiving a nut, the second threaded portion sized to be insertable through the eyebolt opening and able to be locked into place with the nut.
16. A spinal rod coupler assembly providing four degrees of freedom for connecting a spinal rod to a vertebrae of a patient, comprising:
a) a coupler member having a longitudinal bore surrounded by a wall, the bore having a central axis and first and second end portions, the first end portion being open ended and internally threaded, the second end portion being closed;
b) a plurality of openings in the coupler member, each of the openings communicating with the bore;
c) the plurality of openings including a first through opening aligning along a first line that intersects the central axis of the bore at generally right angles, and a second through opening aligning along a second line that intersects the central axis of the bore at generally right angles, the first and second lines being generally perpendicular to each other and spaced apart so that the periphery of the first opening is spaced longitudinally from the periphery of the second opening;
d) the first opening being sized and shaped to receive a spinal rod having a longitudinal axis, the rod's longitudinal axis aligning with the first line of the first opening of the coupler body;
e) an eyebolt member having a shank portion with a central axis and an eye portion, the shank portion being insertable through the second opening of the coupler body, aligning the central axis of the shank with the second line of the second opening, the eye portion having an opening sized and shaped to mate with a selected bone fastener;
f) means for tightening the assembly of the rod and eyebolt in a selected position within the coupler member;
g) whereby the coupler assembly provides for movement along four degrees of freedom which include a movement along and a rotation about the longitudinal axis of the spinal rod, and a movement along and a rotation about the central axis of the eyebolt shank when the assembly is being implanted in a patient.
17. A spinal rod coupler assembly comprising:
a coupler member having first, second, and third openings, the first opening dimensioned to slidably receive a spinal rod and fully surround a portion thereof and the second opening dimensioned to receive a locking fastener to retain the spinal rod within a coupler member; and
a fastener receiving member having an opening to receive a bone fastener, the fastener receiving member rotatably and slidably mounted with respect to the coupler member to adjust the position of the fastener, the fastener receiving member being mountable in the third opening of the coupler member.
18. The coupler assembly of claim 17, wherein a longitudinal axis extending through the first opening is transverse to a longitudinal axis extending though the second opening.
19. The coupler assembly of claim 17, wherein a longitudinal axis extending through the third opening is transverse to the longitudinal axis of the first opening.
20. The coupler assembly of claim 17, wherein the longitudinal axis of the third opening is transverse to the longitudinal axis of the second opening.
21. The coupler assembly of 17, wherein the periphery of the second and third openings are spaced apart.
22. The coupler assembly of 17, wherein the opening in the fastener receiving member is circular in configuration.
23. The coupler assembly of 17, wherein the bone fastener is a bolt.
24. The coupler assembly of 17, wherein the bone fastener is a screw.
25. The coupler assembly of 17, wherein a potion of the second opening of the coupler member is internally threaded.
26. The coupler assembly of 25, further comprising an insert member mountable within the second opening, the insert member having a first recess which conforms to the shape of the spinal rod.
27. The coupler assembly of 26, wherein the fastener receiving member has an elongated shank portion extending into the third opening of the coupler member and the insert has a second recess which conforms to the shape of the shank portion.
28. The coupler assembly of 17, wherein the locking fastener is a set screw engagable with an internal thread formed adjacent the second opening of the coupler member.
29. The coupler assembly of 17, wherein the fastener receiving member has an elongated shank portion extending into the third opening of the coupler member.
30. The coupler assembly of 29, wherein at least a portion of the shank portion has a knurled surface.
31. The coupler assembly of 29, wherein the shank portion is substantially cylindrical in configuration.
32. The coupler assembly of 31, wherein the shank portion has an end portion with a recess formed therein.
33. The coupler assembly of 17, wherein a portion of the coupler opposite the second opening is closed.
34. A spinal rod coupler assembly comprising:
a coupler member having first, second, and third openings, the first opening dimensioned to slidably receive a spinal rod, and the second opening dimensioned to receive a locking fastener to retain the spinal rod within the coupler member, a portion of the coupler opposite the second opening being closed;
a fastener receiving member having an opening to receive a bone fastener, the fastener receiving member rotatably and slidably mounted with respect to the coupler member to adjust the position of the fastener, the fastener receiving member being mountable in the third opening of the coupler member,
and an insert interposed between the spinal rod and the fastener receiving member.
35. The coupler assembly of 34, further comprising a nut engagable with a threaded portion of the bone fastener.
36. A spinal rod coupler comprising:
a first opening dimensioned to slidably receive and fully surround a portion of a spinal rod and having a first longitudinal axis extending therethrough;
a second opening dimensioned to receive a locking fastener and having a second longitudinal axis extending therethrough transverse to the first longitudinal axis; and
a third opening dimensioned to slidably and rotatably receive an elongated connector to mount a bone fastener, the third opening having a third longitudinal axis extending therethrough transverse to the first longitudinal axis and the second longitudinal axis.
37. The spinal rod coupler of claim 36, wherein at least portion of the second opening is threaded.
38. The spinal rod coupler of claim 36, wherein the periphery of the first and third openings are longitudinally spaced.
39. The spinal rod coupler of claim 37, wherein the coupler is substantially cylindrical in configuration.
40. A spinal rod coupler assembly comprising:
a coupler having a first opening to receive a spinal rod and fully surround a portion thereof;
a connecting member having a longitudinal axis, the connecting member extending from the coupler and rotatable with respect to the coupler;
a bone fastener positioned within the connecting member, wherein movement of the connecting member with respect to the coupler adjusts the position of the bone fastener; and
a locking member for securing the spinal rod the locking member extending at an angle to the longitudinal axis of the connecting member.
41. The spinal rod coupler assembly claim 40, wherein the connecting member is slidably movable within a first bore formed in the coupler.
42. The spinal rod coupler assembly of claim 41, wherein the connecting member is rotatably mounted with the first bore.
43. The spinal rod coupler assembly of claim 40, wherein the coupler is slidably mounted with respect to the spinal rod.
44. The spinal rod coupler assembly of claim 40, wherein the coupler is rotatably mounted with respect to the spinal rod.
45. The spinal rod coupler assembly of claim 40, wherein the bone fastener is received in a circular opening in the connecting member.
46. A spinal rod coupler assembly comprising:
a coupler having a first opening to receive a spinal rod;
a connecting member extending from the coupler;
a bone fastener positioned within the connecting member, wherein movement of the connecting member with respect to the coupler adjusts the position of the bone fastener; and
an insert mounted within the coupler and interposed between the spinal rod and connecting member.
47. A spinal rod coupler assembly providing four degrees of freedom for connecting a spinal rod to a vertebrae of a patient, comprising:
a) a coupler member having a longitudinal bore surrounded by a wall, the bore having a central axis and first and second end portions, the first end portion being open ended and internally threaded, the second end portion being closed;
b) a plurality of openings in the coupler member, each of the openings communicating with the bore;
c) the plurality of openings including a first through opening aligning along a first line that intersects the central axis of the bore at generally right angles, and a second through opening aligning along a second line that intersects the central axis of the bore at generally right angles;
d) the first opening being sized and shaped to receive a spinal rod having a longitudinal axis, the rod's longitudinal axis aligning with the first line of the first opening of the coupler body;
e) an eyebolt member having a shank portion with a central axis and an eye portion, the shank portion being insertable through the second opening of the coupler body, aligning the central axis of the shank with the second line of the second opening, the eye portion having an opening sized and shaped to mate with a selected bone fastener;
f) whereby the coupler assembly provides for movement along four degrees of freedom which include a movement along and a rotation about the longitudinal axis of the spinal rod, and a movement along a rotation about the central axis of the eyebolt shank when the assembly is being implanted in a patient.
Description
FIELD OF THE INVENTION

The present invention relates to spinal fixation devices, and more particularly, relates to an improved spinal fixation connector that allows for adjustment in four axes of movement when attaching a longitudinal rod to a vertebrae of a spinal column.

BACKGROUND OF THE INVENTION

There are a number of surgical procedures that require a fixation of portions of the spine with respect to one another. Typically, bone screws or bolts are employed in the fixation of the spine wherein the bone screws or bolts are implanted in a surgical procedure involving the formation of one or more surgical openings in adjacent portions of the spine, for implanting the threaded bone bolts or screws into the vertebrae. Structures such as longitudinal rods or plates extend between the various spine members and are connected to the implanted bone bolts or screws with connector devices.

Connectors for attaching the rods or plates to vertebrae of a spinal column are known in the art. However, current bolt to rod connectors do not allow for adjustability in multiple planes in order to better conform to the anatomical structure of the patient and to eliminate initial stresses on the spinal fixation construct. In spinal surgery that requires distraction, compression, and rotation of the construct to obtain proper assembly, stresses are put on the component parts of existing spinal fixation systems and on the vertebral column, which are not designed to accommodate stresses much higher than those encountered during normal patient activity. By reducing the initial stresses on the construct and the vertebral column, the connector of the present invention allows the entire strength of the connector to be reserved for stresses encountered during patient activity. This provides a spinal construct for a non-compliant patient with activity limitations that is less likely to fail than one with initial high stresses.

Additionally, some existing fixation systems, such as U.S. Pat. Nos. 5,209,752 and 5,176,697, require lateral or medial approaches to assemble and tighten the construct which causes complicated surgical procedures due to the soft tissues that are lateral to the incision. Potential damage can also occur to neurological elements that are medial to the construct.

Current spinal fixation systems, for example such as those shown in U.S. Pat. Nos. 4,719,905 and 5,296,014, also have many pieces to assemble and lack anatomical adjustability which results in long surgeries that put increased stresses on the surgeon and surgical staff. Long surgical times increases patient morbidity due to blood loss and stresses of anesthesia. The large number of pieces in current fixation systems require hospitals to keep large inventories which is difficult during the present time of medical cost containment.

Accordingly, it is a principal object of the present invention to provide a simple and fast way to attach a spinal rod to the spine. The single piece (4 pieces pre-assembled) connector of the present invention facilitates rapid assembly during implantation of the fixation construct. This reduces operating time, blood loss and complications which makes the present invention more appealing to surgeons who will spend less time assembling and adjusting spinal fixation constructs in the operating room.

It is another object of the present invention to provide a spinal fixation connector that has a wide range of adjustability to accommodate a range of anatomical variations and to eliminate the initial stresses on the spinal fixation construct.

It is a further object of the present invention to provide a connector that is secured by means of a single set screw that is accessed from a posterior approach. This provides fewer screws for the surgeon to tighten and makes the securing and tightening of the spinal construct easier to access.

It is a further object of the present invention to provide a connector that allows adjustment in four axes of movement that includes a cephalad/caudal direction, a medial/lateral direction and angulation in a sagittal plane and a transverse plane when the assembly is being implanted in a patient.

SUMMARY OF THE INVENTION

The present invention provides a coupler assembly having four axes of movement for connecting a spinal rod to a vertebrae of a patient with a bone bolt or bone screw. The coupler assembly includes a tubular coupler member having a longitudinal bore surrounded by a wall. The bore has a central axis and first and second end portions with one end being open and internally threaded and the other end portion being closed. A plurality of openings are formed through the wall of the tubular coupler member with each of the openings communicating with the bore.

The plurality of openings include a first pair of openings aligned along a first line that intersects the central axis of the bore at generally right angles, and a second pair of openings aligned along a second line that intersects the central axis of the bore at generally right angles. The first and second pairs of openings are generally perpendicular to each other and are spaced apart so that the periphery of the first pair of openings is spaced longitudinally from the periphery of the second pair of openings. The first pair of openings is sized and shaped to receive a spinal rod with the spinal rod's longitudinal axis aligning with the first line of the first pair of openings of the coupler body.

The coupler assembly also includes an eyebolt having a shank portion with a central axis and an eye portion. The shank portion is insertable through the second pair of openings of the coupler body, with the central axis of the shank aligning with the second line of the second pair of openings. The eye portion of the eyebolt has an opening sized and shaped to mate with a selected bone bolt or bone screw.

An insert having an outer surface that generally conforms to the shape of the bore, fits within the bore. The insert has opposed, arc-shaped end portions with recesses for engaging the spinal rod on one end and the eyebolt on the other end. A set screw threadably engages the internally threaded end portion of the bore so that the set screw tightens the assembly of the rod, insert, and eyebolt within the coupler member when tightened down.

The coupler assembly of the present invention provides for movement along four axes that includes a cephalad/caudad direction, a medial/lateral direction, a sagittal plane and transverse plane when the assembly is being implanted in a patient.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of the invention can be obtained when the detailed description of exemplary embodiments set forth below is reviewed in conjunction with the accompanying drawings, in which:

FIG. 1 is a posterior view of a portion of a vertebral column, showing a spinal fixation device connected to the vertebrae by connectors embodying the present invention;

FIG. 2 is a partial cross-sectional view taken along sight line 22 in FIG. 1, illustrating the manor in which the apparatus of the present invention connect the spinal rods to a vertebrae;

FIG. 3 is a perspective view of the preferred embodiment of the apparatus of the present invention with a spinal rod and bone screw inserted in the apparatus;

FIG. 4 is an exploded perspective view of the preferred embodiment of the apparatus of the present invention;

FIG. 4A is a side plan view of an alternate bone fastener;

FIG. 5A is a side perspective view of the coupler member or the present invention;

FIG. 5B is a cross-sectional view taken along sight line 5B5B in FIG. 5A;

FIG. 5C is a cross-sectional view taken along sight line 5C5C in FIG. 5A;

FIG. 5D is a side plan view of the coupler member of the present invention;

FIG. 6A is a side perspective view of the set screw of the apparatus of the present invention;

FIG. 6B is a cross-sectional view of the set screw in FIG. 6A;

FIG. 7A is a side perspective view of the insert of the present invention;

FIG. 7B is a cross-sectional view taken along sight line 7B7B in FIG. 7A;

FIG. 7C is a cross-sectional view taken along sight line 7C7C in FIG. 7A;

FIG. 8A is a side perspective view of the eyebolt of the present invention;

FIG. 8B is an end plan view taken along sight line 8B8B in FIG. 8a;

FIG. 8C is a lower plan view of the eyebolt of the present invention; and

FIG. 8D is a cross-sectional view taken along sight line 8D8D in FIG. 8A.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

FIGS. 1 and 2 show the preferred embodiment of the coupler assembly of the present invention, designated generally by the numeral 10 implanted in a spinal column. Coupler assembly 10 includes a coupler body or member 30, an eyebolt member 50, an insert 70 and a set screw 80, and is used to attach longitudinal rods 12 to a vertebral column 14 comprising a plurality of vertebrae 16. The coupler assembly 10 is shown attached to three vertebrae 16 as part of a spinal implant system that is used to hold and stabilize vertebrae 16. Although the attachment of only three vertebrae 16 is shown, it should be understood that the number of assemblies 10 used can vary such that any number of vertebrae can be held in place.

Each of the assemblies 10 is connected to a respective vertebrae 16 by a fastener 18 which may be either a bone bolt (FIGS. 2, 3, 4) or a bone screw 18A (FIG. 4A). The fastener 18 is shown in FIGS. 2, 3 and 4 as bone bolt 18 having a first threaded end portion 22 for threaded engagement with an opening formed in a pedicle 20 of the vertebrae 16. Bolt 18 includes a shoulder portion 24 which establishes how far the first threaded end portion 22 can extend into the vertebrae 16 and spaces the assembly 10 away from the vertebrae 16. Bolt 18 has a second threaded end portion 26 extending past the pedicle 20 for engaging the eyebolt 50 of the assembly 10. The bone bolt 18 also includes a nut 28 that can be threaded upon the threaded end portion 26 of the bolt 18 to secure eyebolt 50 of assembly 10 against the bolt shoulder 24. Bone screw 18A includes a first threaded end portion 22A and a head portion 28A having a spherically shaped lower portion.

After bone bolt 18 has been implanted in pedicle 20 of the vertebrae 16, assembly 10 is placed over the threaded end portion of 26 of the bolt 18. The nut 28 is threaded over the end portion 26 in order to securely fasten the bone bolt 18 to the assembly 10. The longitudinal rod 12, having a longitudinal axis A1A1 (FIG. 4) is placed through an opening in the assembly 10 and the set screw 80 secures the entire assembly 10A together (FIGS. 3, 4). The coupler assembly 10A includes the coupler assembly 10, the spinal rod 12 and the bone fastener 18.

In the embodiment of the present invention shown in FIG. 4, the assembly 10 includes the cylindrical coupler body or member 30, the eyebolt member 50, insert 70, and the set screw 80 that when assembled forms the single piece coupler assembly 10. In a preferred embodiment, the coupler body 30 is tubular in shape and has a longitudinal bore 32 surrounded by a wall 34. The bore 32 has a central axis C1 and a first or top portion 36 and a second or bottom portion 38. The top portion 36 is open-ended and includes internal threading 40. The second or bottom end portion 38 is closed. The coupler body 30 also has an upper portion 36A and a lower portion 38A. In a preferred embodiment, the upper portion 36A of the coupler body 30 has a larger diameter in relation to the lower portion 38A.

Coupler body 30 includes at least two through openings. In a preferred embodiment, coupler body 30 includes a first pair of openings through wall 34 aligned along a first line L1L1 that intersects the central axis C1 of bore 32 at generally right angles (FIGS. 5A, 5B). Coupler body 30 also includes a second pair of openings 44 aligned along a second line L2L2 that intersects the central axis C1 of bore 32 at generally right angles (FIGS. 5A, 5C). Openings 42 and 44 are generally perpendicular to each other and spaced apart from each other such that the periphery of the first pair of openings 42 is spaced longitudinally from the periphery of the second pair of openings 44 as shown in FIGS. 3, 4 and 5A. In a preferred embodiment, openings 42 are placed in the upper portion 36A of coupler body 30 and openings 44 are placed in the lower portion 38A of coupler body 30.

Openings 42 are sized and shaped to receive the spinal rod 12 with the longitudinal axis A1 of the rod 12 aligning with the line L1L1 of the openings 42 when the rod 12 is placed through openings 42 of coupler body 30 (FIG. 3). Openings 44 have a lower wall portion 46 which is concave in shape in order to accommodate the cylindrical shank portion of the eyebolt 50 (FIG. 5B).

In a preferred embodiment, a pair of notches 48 are positioned on the outside surface of wall 34 at the open-ended portion 36 of coupler body 30 (FIGS. 5A, 5D). The notches 48 are sized and shaped to accommodate a tool such as a wrench which is used to stabilize the coupler body 30 while the set screw 80 is being tightened into place.

Eyebolt member 50 includes a shank portion 52 and an eye portion 54 (FIG. 8A). Shank portion 52 has a central axis C2C2 and an outer surface 56 (FIG. 8C). In a preferred embodiment, shank portion 52 is cylindrical in shape with knurling 58 on a portion of the outer surface 56 (FIGS. 8A, 8C). Shank portion 52 includes a shank end 64 with a recess 66 so as to allow slight flanging of shank end 64 after the shank portion 52 is inserted through openings 44 of coupler body 30 (FIGS. 8B, 8D). The flanging prevents the shank portion 52 from sliding out of the openings 44 after the coupler assembly 10 has been assembled. When shank portion 52 of eyebolt 50 is inserted through openings 44 of coupler body 30, the shank portion's 52 central axis C2C2 is aligned along line L2L2 of openings 44 (FIG. 3).

Eye portion 54 of eyebolt 50 includes an opening 60, an upper surface 61, and a lower surface 62. Opening 60 has a spherically shaped surface 63 on the upper and lower surfaces 61, 62 of eye portion 54 and is sized and shaped to mate with the fastener 18. When implanted in a patient, the spherically shaped nut 28 mates with the spherically shaped surface 63 on the upper surface 61 of the eye portion opening 60 and the spherically shaped shoulder portion 24 mates with the spherically shaped surface 63 on the lower surface 62 of the eye portion opening 60. If the bone screw 18A is used as the bone fastener instead, the spherically shaped surface of the bone screw head portion 28A mates with the spherically shaped surface 63 on the upper surface 61 of the eye portion opening.

Insert 70 is cylindrical in shape and has opposed arc-shaped end portions 72, 76 (FIG. 7A). First end portion 72 has a recess 74 that is sized and shaped to engage the spinal rod 12 (FIGS. 7A, 7B). Second end portion 76 has a recess 78 sized and shaped to engage the shank portion 52 of eyebolt 50 (FIGS. 7A, 7C). Insert 70 has an outer surface 71 that generally conforms to the shape of bore 32 of coupler body 30.

During assembly of the coupler assembly 10, insert 70 is placed in bore 32 after the shank portion 52 of eyebolt 50 has been placed through openings 44 of coupler body 30. Insert 70 is placed in bore 32 such that recess 78 contacts the outer surface 56 of shank portion 52 of eyebolt 50. When the spinal rod 12 is placed through the openings 42, recess 74 of insert 70 contacts the surface of the spinal rod 12. Thus, insert 70 provides greater surface to surface contact between the rod 12 and shank portion 72 then would be possible if the coupler assembly 10 was used without insert 70. In a coupler assembly 10 without insert 70, there would only be a single point of surface contact between the inserted rod 12 and shank portion 52 when they are in the perpendicular alignment allowed by the openings 42 and 44 of the coupler body 30.

Set screw 80 has an upper surface 82, a lower surface 84, and a threaded body portion 86 that engages and cooperates with the internally threaded end portion 36 of coupler body 30. Upper surface 82 is generally flat with a tool receptive socket 88 sized and shaped for receiving a tool designed to thread and tighten the set screw 80 into the threaded portion 40 of bore 32 of coupler body 30. In a preferred embodiment, lower surface 84 has a smooth outer surface and is generally conical in shape. The set screw 80 provides means for tightening the rod 12, insert 70, and eyebolt 50 within the coupler body 30.

In alternate embodiments, the coupler body can include a U-shaped top opening, sized and shaped to receive the spinal rod 12, instead of the pair of openings 42. A cap or a cross-bar with at least one set screw can be used to tighten the assembly 10 together instead of the set screw 80.

Coupler assembly 10 is assembled by placing shank portion 52 of eyebolt 50 through openings 44 of coupler body 30. Insert 70 is inserted in the bore 32 so as to allow recess 78 to engage the outer surface of shank portion 52. Set screw 80 is partially threaded into bore 32 which provides the single piece assembly 10 as shown in FIG. 3. After the fastener 18 has been implanted in pedicle 20 of vertebrae 16, the threaded end 26 of bone bolt 18 is inserted through the eyebolt opening 60 of coupler assembly 10. Spinal rod 12 is inserted through openings 42 such that the spinal rod 12 engages recess 74 of insert 70. After the coupler assembly 10 and rod 12 have been adjusted to conform to the anatomical structure of the vertebral column 14, set screw 80 is tightened into bore 32 of coupler body 30, securing the entire assembly 10A in place in the selected position.

The coupler assembly 10 allows for adjustment along four degrees of freedom, as shown in FIG. 3. Assembly 10 allows for movement along the longitudinal axis A1A1 of spinal rod 12 which provides adjustment in a cephalad-caudad direction CCCC. Eyebolt 50 can be moved in the openings 44 along the central axis C2 of shank portion 50 allowing for adjustment in a medial-lateral direction MLML. The rotation of the spinal rod 12 around its longitudinal axis A1A1 in the openings 42 allows for angulation in a transverse plane TATA. The rotation of the eyebolt 50 around its central axis C2C2 in openings 44 allows for angulation in a sagittal plane SASA.

Thus, the present invention provides a single piece connector for attaching a spinal rod to a vertebrae that facilitates rapid assembly and allows a wide range of adjustability in four axes of movement.

The coupler assembly 10 is formed of a biocompatible material, and in a preferred embodiment, is formed of stainless steel.

It should be understood that there can be improvements and modifications made to the embodiments of the invention described in detail above without departing from the spirit or scope of the invention, as set forth in the accompanying claims.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US4569338 *9 Feb 198411 Feb 1986Edwards Charles CSacral fixation device
US4648388 *1 Nov 198510 Mar 1987Acromed CorporationApparatus and method for maintaining vertebrae in a desired relationship
US47199051 Dec 198619 Jan 1988Acromed CorporationApparatus and method for maintaining vertebrae in a desired relationship
US4771767 *3 Feb 198620 Sep 1988Acromed CorporationApparatus and method for maintaining vertebrae in a desired relationship
US498789221 Dec 198929 Jan 1991Krag Martin HSpinal fixation device
US5024213 *8 Feb 198918 Jun 1991Acromed CorporationConnector for a corrective device
US5053034 *26 Oct 19901 Oct 1991Sven OlerudSpinal joint
US508404829 Jun 199028 Jan 1992Sulzer Brothers LimitedImplant for vertebrae with spinal stabilizer
US5129900 *24 Jul 199014 Jul 1992Acromed CorporationSpinal column retaining method and apparatus
US5176679 *23 Sep 19915 Jan 1993Lin Chih IVertebral locking and retrieving system
US517669728 Sep 19905 Jan 1993Hasson Harrith MLaparoscopic cannula
US52097524 Dec 199111 May 1993Danek Medical, Inc.Lateral offset connector for spinal implant system
US522295421 Jun 199129 Jun 1993Artifex, Ltd.Spinal implant system and method for installing the implant
US52541184 Dec 199119 Oct 1993Srdjian MirkovicThree dimensional spine fixation system
US526190918 Feb 199216 Nov 1993Danek Medical, Inc.Variable angle screw for spinal implant system
US529601426 Aug 199222 Mar 1994Saint-Gobain Vitrage InternationalDevice for bending glass sheets on bending mold having a cover
US5306275 *31 Dec 199226 Apr 1994Bryan Donald WLumbar spine fixation apparatus and method
US531240420 Feb 199217 May 1994Acromed CorporationSpinal column retaining apparatus
US5344422 *10 Dec 19926 Sep 1994Synthes (U.S.A.)Pedicular screw clamp
US538032316 Jun 199310 Jan 1995Advanced Spine Fixation Systems, Inc.Clamps for spinal fixation systems
US5437669 *12 Aug 19931 Aug 1995Amei Technologies Inc.Spinal fixation systems with bifurcated connectors
US5437671 *7 Mar 19941 Aug 1995Zimmer, Inc.Perpendicular rod connector for spinal fixation device
US5478340 *28 Jan 199326 Dec 1995Kluger; PatrickVertebral column implant and repositioning instrument
US549826225 Apr 199412 Mar 1996Bryan; Donald W.Spinal fixation apparatus and method
US5501684 *25 Jun 199226 Mar 1996Synthes (U.S.A.)Osteosynthetic fixation device
US550774627 Jul 199416 Apr 1996Lin; Chih-IHolding and fixing mechanism for orthopedic surgery
US5520688 *20 Jul 199428 May 1996Lin; Chih-IVertebral auxiliary fixation device
US55273144 Jan 199318 Jun 1996Danek Medical, Inc.Spinal fixation system
US55626627 Jun 19958 Oct 1996Danek Medical Inc.Spinal fixation system and method
US56095927 Jun 199511 Mar 1997Danek Medical, Inc.Spinal Fixation System
US561180015 Feb 199418 Mar 1997Alphatec Manufacturing, Inc.Spinal fixation system
US563492526 Apr 19953 Jun 1997Alphatec Manufacturing, Inc.Apparatus and method for spinal fixation system
US5643259 *31 Mar 19941 Jul 1997Ricardo C. SassoSpine fixation instrumentation
US5667506 *14 Mar 199516 Sep 1997Danek Medical, Inc.Spinal rod transverse connector for supporting vertebral fixation elements
WO1994023661A1 *19 Apr 199427 Oct 1994Patrick HenryMounting member for an osteosynthesis device
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US7569070 *6 Jan 20064 Aug 2009Showa Ika Kohgyo Co., Ltd.Rod connector
US7575587 *30 Dec 200518 Aug 2009Warsaw Orthopedic, Inc.Top-tightening side-locking spinal connector assembly
US7896905 *8 Feb 20061 Mar 2011David LeeBone fixation apparatus
US802568231 Aug 200727 Sep 2011Depuy Spine, Inc.Method and system for securing a rod to a bone anchor with a connector
US8029543 *28 Oct 20034 Oct 2011Warsaw Othopedic, Inc.Multi-axial, cross-link connector system for spinal implants
US805751831 Aug 200715 Nov 2011Depuy Spine, Inc.Spanning connector for connecting a spinal fixation element and an offset bone anchor
US81679123 Aug 20071 May 2012The Center for Orthopedic Research and Education, IncModular pedicle screw system
US8246658 *29 Oct 201021 Aug 2012Warsaw Orthopedic, Inc.Spinal connector assembly
US825203010 Mar 200928 Aug 2012Globus Medical, Inc.Spinal implant connection assembly
US831351515 Jun 200720 Nov 2012Rachiotek, LlcMulti-level spinal stabilization system
US83178375 Feb 201027 Nov 2012Warsaw Orthopedic, Inc.Connector and method
US83431524 Apr 20121 Jan 2013Toby Orthopaedics, Inc.Fixed angle dual prong pin fixation system
US851234331 Aug 200720 Aug 2013DePuy Synthes Products, LLCMethods and instruments for approximating misaligned vertebra
US862855926 Jul 201214 Jan 2014Globus Medical, Inc.Spinal implant connection assembly
US865785630 Aug 201025 Feb 2014Pioneer Surgical Technology, Inc.Size transition spinal rod
US20070293861 *27 Aug 200720 Dec 2007Alan RezachGrommet assembly
US20120109209 *29 Oct 20103 May 2012Warsaw Orthopedic, Inc.Spinal Connector Assembly
Classifications
U.S. Classification606/264, 606/278
International ClassificationA61B17/70, A61B17/86
Cooperative ClassificationA61B17/7041, A61B17/7035
European ClassificationA61B17/70B6, A61B17/70B5
Legal Events
DateCodeEventDescription
8 Aug 2006CCCertificate of correction
28 Aug 2002ASAssignment
Owner name: HOWMEDICA OSTEONICS CORP., NEW JERSEY
Free format text: MERGER;ASSIGNOR:SURGICAL DYNAMICS INC.;REEL/FRAME:013229/0448
Effective date: 20020701
11 Dec 1997ASAssignment
Owner name: SURGICAL DYNAMICS, INC., CONNECTICUT
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:UNITED STATES SURGICAL CORPORATION;REEL/FRAME:008992/0283
Effective date: 19971210
Owner name: UNITED STATES SURGICAL CORPORATION, CONNECTICUT
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:SMITH & NEPHEW, INC.;REEL/FRAME:008957/0238
Effective date: 19971204
Free format text: (ASSIGNMENT OF ASSIGNOR S INTEREST) RE-RECORD TO CORRECT THE NUMBER OF MICROFILM PAGES FROM 10 TO 5. AN ASSIGNMENT WAS PREVIOUSLY RECORDED AT REEL 8957, FRAME 0238.;ASSIGNOR:SMITH & NEPHEW, INC.;REEL/FRAME:008992/0286
28 Nov 1997ASAssignment
Owner name: IBM CORPORATION, NEW YORK
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:TREPP, ROBERT MARTIN;REEL/FRAME:008851/0306
Effective date: 19971128