USRE46115E1

USRE46115E1 - Bone screw apparatus, system and method

Info

Publication number: USRE46115E1
Application number: US13/911,397
Authority: US
Inventors: Todd J. Albert
Original assignee: EBI LLC
Current assignee: Zimmer Biomet Spine Inc
Priority date: 2005-09-19
Filing date: 2013-06-06
Publication date: 2016-08-23
Also published as: US20070093819A1; US7955358B2

Abstract

A bone screw apparatus, system, and method for assisting in the placement and alignment of a bone screw and for aligning bone are described. The present invention allows a surgeon to position a bone screw in a desired position and adjust a coupling element in a variety of positions and angles with respect to the bone screw.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an orthopedic implant. In particular, the present invention relates to a bone screw apparatus, system, and method.

2. Description of Related Art

Conventional bone screws and precursory polyaxial screws have found wide usage in orthopedic spinal surgery. Such devices are routinely used to address spinal instability and displacement, genetic or developmental irregularities, trauma, chronic stress, tumors, and disease. However, such designs are not without limitation. For example, conventional bone screws used with fixation rods , provide for minimal, if any variability in the placement of these rods relative to the position of the bone screw. Specifically, such conventional designs limit the positioning of the rod such that it is aligned with and/or above the screw. The rod itself makes direct contact with the screw head and is used to secure the screw into a coupling element in order to lock or secure the entire assembly into place. As a result, a surgeon is forced to try and position the screw taking into account the position of the rod and being generally unable to move the screw into the most optimal or strategic position. These limitations may cause the surgeon to reposition the bone screw in order to correctly align the system and as a result cause additional and unnecessary weakening of the bone due to, for example, additional screw holes created by the repositioning and/or stress on the bone screw interface by forcible repositioning. Further, while some bone screws allow for limited radial movement of the coupling element, medial-lateral variability of the placement of these rods relative to the screw is curtailed.

Accordingly, there exists a need for an improved bone screw alignment system that provides ease of use and modularity of assembly and that eliminates the problems set forth above.

BRIEF SUMMARY OF THE INVENTION

The present invention provides for an apparatus for coupling a bone screw to a connector, comprising; a housing that includes; an aperture for receiving a connector, a base having a slot configured for receiving at least one bone screw, and wherein the housing is configured to receive a fixation element.

The present invention also provides for a bone screw apparatus comprising; a coupling element that includes; a housing having; an aperture and a base having a slot; a connector extending through the aperture; a bone screw positioned within the slot; and a fixation element configured to secure the coupling element, connector, and bone screw in a fixed position.

The present invention further provides for a bone screw system comprising; a connector; and at least two bone screw apparatuses each comprising; a coupling element that includes; an aperture, wherein the connector extends through the aperture, and a base having slot; a bone screw positioned within the slot; and a fixation element configured to secure the coupling element, connector, and bone screw in a fixed position.

The present invention furthermore provides for a method for aligning and placing a bone screw system in bone, wherein the bone screw system includes; a connector; and at least a first and a second bone screw apparatus, wherein each bone screw apparatus has a coupling element having an aperture; and a base having a slot; a bone screw positioned within the slot; and a fixation element, wherein the connector extends through the aperture and wherein the fixation element is configured to secure the coupling element, connector, and bone screw in a fixed position, comprising; (a) positioning the first bone screw of the first bone screw apparatus in the slot of the first coupling element, (b) screwing the first bone screw into bone, (c) positioning the second bone screw of the second bone screw apparatus in the slot of the second coupling element, (d) screwing the second bone screw into a second bone, (e) aligning the coupling elements relative to the first and second bone screws, (f) extending the connector through each of the aligned coupling elements, and (g) securing the alignment of the first and second bone screw apparatuses in a fixed position.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The foregoing summary, as well as the following detailed description of the embodiments of the invention, will be better understood when read in conjunction with the appended drawings. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. In the drawings:

FIG. 1 is a perspective view of a bone screw apparatus embodiment of the present invention;

FIG. 2 is a perspective view of a coupling element of the bone screw apparatus of FIG. 1;

FIG. 3 is an anterior perspective view of the coupling element of FIG. 2;

FIG. 4 is a perspective view of an optional locking wedge for use with the bone screw apparatus of FIG. 1;

FIG. 5 is a plan view of a polyaxial screw of the bone screw apparatus of FIG. 1;

FIG. 6 is an anterior perspective view of a another embodiment of a bone screw apparatus of the present invention;

FIG. 7 is a perspective view of a further embodiment of the present invention;

FIG. 8 is an anterior perspective view of yet another embodiment of a bone screw apparatus of the present invention; and

FIG. 9 is an illustration of a bone screw system of the present invention affixed to bone.

DETAILED DESCRIPTION OF THE INVENTION

As used herein, the following definitional terms apply. The term “anterior” and “posterior” mean nearer to the front or the back of the body respectively. “Proximal” and “distal” mean nearer and farther from the center of the body respectively. “Medial” and “lateral” mean nearer or farther from the median plane respectively. The median plane is an imaginary, vertical plane that divides the body into a right and left half. A coronal plane is an imaginary, vertical plane that divides the body into a front half and a back half. “Superior” and “inferior” mean above or below respectively. “Sagittal” means a side profile.

The present invention provides for a bone screw apparatus, system, and method for attaching a connector to a vertebra.

In an embodiment, as illustrated in FIGS. 1-5, the present invention provides for a bone screw apparatus 1 that includes a coupling element 2, a fixation element 8, a connector 30, a locking wedge 40, and a bone screw 50.

As illustrated in FIG. 2, the coupling element 2 includes an upper housing 4 and a lower housing 6. A fixation element 8 as shown in FIG. 1 is inserted into the apparatus 1. The coupling element 2, can optionally be configured as a single housing only. In the present embodiment the fixation element is a locking screw 8 and the coupling element 2 has a connector 30 therethrough as shown in FIG. 1.

The upper housing 4 and lower housing 6 units can be an integral one-piece unit or separate units connected together by any acceptable means (e.g., taper lock, mechanical locking mechanism, screw, dovetail, bonding, and the like). The upper housing 4 has a cross-sectional shape perpendicular to axis A that is generally circular in shape but can also be any shape consistent with the intended use, such as a square, rectangle, oval, or the like. Further, the outer cross-sectional shape can vary from the cross-sectional shape of hole 10 extending therethrough. The upper housing 4 is configured to accommodate the fixation element 8. In this embodiment, the upper housing 4 is configured to have a hole 10 that can receive and accommodate a locking screw 8 (e.g., a set screw). It is preferred that the interior surface 11 defining the hole 10 is threaded, but other embodiments such as snap-fit, cross-threading, interlocking, and dovetailing can also be used.

The lower housing 6 can be wider or narrower measured perpendicular to axis A in the longest dimension of the device than the upper housing 4. In the present embodiment, the lower housing 6 is wider than the upper housing 4 and is generally configured as illustrated in FIGS. 2 and 3. However, the shape of the lower housing 6 can be any other shape consistent with the intended use, such as a cross-sectional shape perpendicular to axis A that is circular, oval, or square so long as it can accommodate a slot 12.

The lower housing 6 includes a slot 12 as illustrated in FIG. 3. The slot 12 can be positioned at the base 14 of the lower housing 6. The base 14 can be integrally formed as part of the lower housing 14, a separately formed and attached piece, or a prefabricated interchangeable insert having a slot 12.

The base 14 has a posterior surface 16 (as shown in FIG. 2) and an anterior surface 18. The slot 12 is formed so as to extend between

surfaces

16 and 18 and includes a plurality of slot positions 20, including a center slot position 20a. The slot 12 can alternatively include at least two slot positions, or a smooth peripheral, oval shaped or capsule shaped slot (i.e., a continuous slot). The slot 12 allows the coupling element 2 to be positioned more medially, laterally, superiorly, or inferiorly relative to the position of the bone screw 50. This advantageously allows the surgeon to optimally position the bone screw 50 without being limited by the constraints of a connector's position.

In the present embodiment, the slot 12 includes five slot positions 20 and a center slot position 20a positioned directly below the threaded hole 10. The slot positions 20 are circular in shape but can be any other shape consistent with the intended use. As illustrated in FIG. 2, the slot positions are overlapping and form notches 22. The notches 22 facilitate positioning of the bone screw 50 into a bone by helping to prevent the bone screw 50 from moving to another slot position and guiding the bone screw 50 as the screw is being drilled into the bone. The notches 22 further provide for greater contact area between the bone screw 50 and the coupling element 2, which improves the overall structural integrity of the bone screw apparatus 1 when in use.

The slot positions 20 and generally the edge of the slot 20 can optionally be configured to have or be contoured with a beveled edge 24 as shown in FIG. 3 or a round edge (not shown). The edge 24 can be complementary in shape to that of the screw head 52. The contoured edge facilitates movement (e.g., polyaxial movement) of the bone screw 50 within the coupling element 2 due to its generally complementary configuration to that of the curvate polyaxial screw head 52 (as shown in FIG. 5) of the bone screw 50.

The lower housing 6 can include an aperture 26 as shown in FIG. 1. The aperture 26 allows the placement of a connector, such as rod 30, within the coupling element 2 such that the connector (e.g., rod 30) is generally centered within the coupling element 2, allowing for greater stability when fastening the locking screw 8 into place. The aperture 26 can be configured so as to allow the connector to be perpendicular to plane B or at an angle relative to plane B, as illustrated in FIG. 1. The lower housing 6 can also include a visibility hole 28. The visibility hole 28 advantageously allows the surgeon to be able to see the polyaxial screw 50 during assembly of the bone screw apparatus 1.

As illustrated in FIG. 2, the lower housing 6 can optionally include

angled ridges

32a, 32b positioned on the interior surface of the lower housing 6 of coupling element 2 for mating with

angled flats

49a, 49b of an optional locking wedge 40 (as shown in FIG. 4 and described below). Together, the

angled flats

49a, 49b of the locking wedge 40 and angled

ridges

32a, 32b form a wedge for mating and securing locking wedge 40 into place. The

angled ridges

32a, 32b can be slightly steeper than the

angled flats

49a, 49b. The

angled flats

49a, 49b help locking wedge 40 remain level and parallel with the base 14 of the coupling element 2, to facilitate maintaining the alignment of the rod 30.

In the present embodiment, the fixation element is configured to be a locking screw 8 as shown in FIG. 1. The fixation element, without limitation, can also be a cam lock, a taper lock, an interference fit, a locking tab, a tapered wedge, a locking collar, a dovetail, or any other configuration consistent with the intended use. The fixation element can be positioned anywhere within the coupling element 2 such that the fixation element provides a securing force to the bone screw apparatus 1 (e.g., secures the coupling element 2, rod 30, and the bone screw 50 in a fixed position). For example, the fixation element can be in an upper housing 4 or the lower housing 2 of the coupling element. Examples of such fixation elements are readily known in the art and a detailed explanation of such fixation elements is not necessary for a complete understanding of the present invention.

The present embodiment further includes a connector. In the present embodiment the connector is configured as a rod 30. The connector, without limitation, can also be a cylindrical rod, a square rod, an oval rod, a rectangular rod, a hollow rod, or any other longitudinal member consistent with the intended use.

The present embodiment can optionally include a locking wedge 40 as configured and illustrated in FIG. 4. The locking wedge 40 includes an optional connector channel 42, a tool hole 44, and a concave channel 46 defined by the downwardly extending sides 48 of the locking wedge 40. The locking wedge 40 can optionally include

angled flats

49a, 49b to mate with

angled ridges

32a, 32b on the lower housing 6 of the coupling element as discussed above. The angle of the

angled flats

49a, 49b can be from 0 to about 89 degrees, and preferably about 35 to about 55 degrees. The locking wedge 40 can be made from a metal, alloy, polymer, or any combination thereof.

The connector channel 42 is formed on the posterior side of the locking wedge 40 and is configured to cradle or support and preferably mate with the surfaces of the rod 30 as it extends or passes through the device. The connector channel 42 can be indented into the locking wedge 40 as illustrated in FIG. 4. The configuration of the connector channel 42 allows the rod 30 to be positioned perpendicular to or at an angle relative to plane B, as shown in FIG. 1. The tool hole 44 is configured to be a circular through hole but can, without limitation, be any shaped through hole. The tool hole 44 can be positioned at the center of the locking wedge 40, which helps a surgeon better manipulate the bone screw 50. The size of the tool hole 44 is configured to accommodate a range of motion for a surgical tool, such as a screwdriver or drill (not shown), such that the screw head 52 (as shown in FIG. 5) can be accessed by the surgical tool even when the bone screw 50 is at its maximum angulation.

The bone screw 50 of the present embodiment is illustrated in FIG. 5. Bone screw designs, like the surgical tools discussed above, are readily known in the art and a detailed explanation of them are not necessary for a complete understanding of the present invention. The present embodiment of the invention is not limited to polyaxial screws but can alternatively include non-polyaxial screws such as a posted bone screws or posted/polyaxial bone screws.

In the present embodiment, the bone screw 50 includes a head 52 and a threaded shaft 54. The head 52 is configured to have a predominately curvate shape such as a spherical outer surface or a hemispherical shape. The head 52 further includes at least one recess 56 positioned on the top of the bone screw 50 to receive the application of a torque driving tool, such as a screw driver or drill. The recess 56 can alternatively be any configuration that cooperates with any suitable torque driving tool, such as a phillips head configuration, allen wrench, or the like. It is noted that the size of the head 52 and diameter of the threaded shaft can vary depending upon the individual circumstances and size requirements for a particular use or patient. As the size of the bone screw 50 changes, the size of other corresponding components of the bone screw apparatus 1 should change accordingly.

In an assembled state, the bone screw 50 is adjustably positioned within the lower housing 6 with its head 52 positioned within the lower housing 6 and in one of the slot positions 20. The spherical shape of the screw head 52 allows the bone screw 50 to be angled relative to axis A. The locking wedge 40 is positioned within the lower housing 6 such that the concave channel 46 contacts the screw head 52. The rod 30 is then positioned to extend through the coupling element 2 and in contact with or on the connector channel 42. The shape of the connector channel 42 allows the rod 30 to be either perpendicular to or at an angle relative to the direction of the concave channel 46. The locking screw 8 is then screwed (i.e. torqued down) into the threaded hole 10 of the upper housing 4 until sufficient contact is made with the rod 30. As the locking screw 8 is screwed down, it pulls the coupling element 2 posteriorly. As the locking screw 8 is screwed down, it pushes anteriorly onto the rod 30 transmitting a securing force (e.g., an anteriorly directed force) onto the rod 30. Thus, the locking screw 8 supplies an anterior force (i.e., a securing force) to the rod 30 which further transmits a securing force onto the locking wedge 40 which, as a result, secures the coupling element 2 and the bone screw 50 in a fixed position. Overall, the anterior force of the locking screw 8 and the resulting posterior force of the coupling element assembles the bone screw apparatus 1 into a secure and stable position regardless of which slot position 20 the bone screw 50 is located.

In operation, the coupling element 2 can be preassembled with the bone screw 50, which is positioned loosely in a center slot position or the center of the slot 12. Locking wedge 40 can be positioned inside the coupling element 2 such that

angled flats

49a, 49b lie loosely on top of angled

ridges

32a, 32b of coupling element 2. The concave channel 46 of locking wedge 48 can contact the screw's head 52 as it is positioned in the coupling element 2. A screw-driving tool (not shown) is then inserted through the coupling element 2 from above such that it passes through the upper housing 4 and through tool hole 44 of locking wedge 40. The driving tool then secures bone screw 50 into the bone at a strategic place as determined by the surgeon. Once bone screw 50 is secured into the bone, coupling element 2 is able to move along a plane of the bone surface. That is, coupling element 2 is able to travel along the length of the slot 12 relative to the position of the bone screw 50, and is able to rotate a full 360 degrees around the screw head 52. Coupling element 2 can then be slid medio-laterally for optimal positioning, or rotated in the same plane if needed, so that upper housing 4 lines up with the rod 30 and the screw head 52 is positioned in one of the slot positions 20.

Once screw head 52 is located in the proper slot position 20, the surgeon then inserts rod 30 into the coupling element 2 via through hole 26, wherein the rod 30 is positioned on connector channel 42 of locking wedge 40. The surgeon can then use the screw-driving tool to fasten locking screw 8 onto the upper housing 4 of coupling element 2. Locking screw 8 is then tightened or screwed down until locking wedge 40 engages the screw head 52 (e.g., by being compressed between rod 30 and the screw head 52). Coupling element 2 is pulled upwards as locking screw 8 is tightened so that screw head 52 is secured inside slot position 20 of slot 12.

To remove the bone screw apparatus 1, locking screw 8 can be unfastened and rod 30 removed. Locking wedge 40 is loosened by insertion of a tool (not shown) through tool hole 44. A gripping tool (not shown) may then be used to push down on coupling element 2 and the coupling element 2 slid such that screw head 52 can be located in a center slot position, allowing for the screw driving tool to access and loosen the bone screw 50.

FIG. 6 illustrates another embodiment of the present invention. In this embodiment the bone screw apparatus 100 includes a coupling element 102 having a continuous slot 104.

FIG. 7 illustrates a further embodiment of the present invention. In this embodiment, the bone screw apparatus 200 includes a coupling element 202 having two bone screws 204a, 204b for screwing into a bone.

FIG. 8 illustrates yet another embodiment of the present invention. In this embodiment, bone screw apparatus 300 includes a coupling element 302 having a slot 304 with an anterior surface 306 and a posterior surface 308 (not shown). The slot 304 includes five slot positions 310. The slot 304 includes a continuous beveled edge 312 configured to have three diameters D1, D2, and D3 positioned along the edge between surfaces 306, 308. D1 is the largest diameter adjacent the posterior surface 308. For illustrative purposes only, for a bone screw head having a 3.5 mm diameter head, D1 can be 3.6 mm, which is larger than the diameter of the polyaxial screw head and allows the maximum amount of motion for the bone screw before it is secured into the bone. The beveled edge 312 then tapers down into a second diameter D2 that measures, for example, 3.4 mm. This diameter D2, which is slightly smaller than that of the diameter of the polyaxial screw head, helps prevents the screw head from slipping through the slot positions 310. Located below diameter D2 is diameter D3. The diameter D3, for illustrative purposes only, is 3.5 mm that allows the screw to retain about 30 degrees angulation relative to the vertical. To increase this angulation, the diameter D3 can be increased.

The present invention also provides for a bone screw system 400 as shown in FIG. 9. The bone screw system 400 includes a least two bone screw apparatuses 402a, 402b and a connector 404. Each bone screw apparatus, for example 402a, includes a coupling element having an aperture, a fixation element, an optional locking wedge, and at least one bone screw 406. In operation, as shown in FIG. 9, the connector 404, is attached to and extends through at least two bone screw apparatuses 402a, 402b that are each independently affixed to a bone.

The present invention further provides for a method for placing and aligning a bone screw system (as describe above) in bone. The method includes positioning a bone screw in a slot of a coupling element (as described in any of the above embodiments), inserting the bone screw into the bone, repositioning the coupling element relative to the bone screw, and securing the alignment and position of the coupling element, and bone screw. The method can further include positioning a connector (as described in any of the above embodiments) through the coupling element, and securing the alignment and position of the connector, coupling element, and bone screw.

The present invention also provides for a method for aligning bones. The method includes providing a bone screw system. The bone screw system includes at least two bone screw apparatuses that each include a coupling element having a connector therethrough and a slot, and a bone screw positioned within the slot, wherein the connector transmits a securing force securing the coupling element and bone screw in a fixed position.

The present invention advantageously allows for additional positioning freedom between a bone screw and a connector in multiple degrees of freedom including the medial, lateral, superior, and inferior directions.

It will be appreciated by those skilled in the art that changes can be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.

Claims

I claim:

1. An apparatus for coupling a bone screw to a connector, comprising:

a housing that includes:

an aperture for receiving a connector, and

a base having:

a generally flat anterior surface,

a generally flat posterior surface, and

a generally oblong opening formed by a substantially linear surface extending from the anterior surface to the posterior surface,

at least one polyaxial bone screw directly engaging the substantially linear surface forming the generally oblong opening, and

a fixation element adjustably mounted to the housing that engages both the connector and the at least one polyaxial bone screw to secure both the connector and the at least one polyaxial bone screw to the housing in a fixed position,

wherein the housing comprises:

a lower housing,

an upper housing, and

wherein the upper housing is configured to receive the fixation element.

2. The apparatus of claim 1, wherein the housing comprises:

a lower housing,

an upper housing, and

wherein the upper housing is configured to receive the fixation element.

3. The apparatus of claim 1, wherein the oblong opening includes a plurality of notches defining a plurality of slot positions.

4. The apparatus of claim 1, wherein the aperture is an oblong aperture with a major axis of the oblong opening extending substantially parallel to a major axis of the oblong aperture.

5. A bone screw apparatus comprising:

a coupling element that includes:

a housing having:

an oblong aperture extending through the housing, and

a base having a generally oblong opening with a major axis of the oblong opening extending substantially parallel to a major axis of the oblong aperture,

a connector extending through the oblong aperture,

a head of a polyaxial bone screw positioned in direct engagement with a wall of the housing forming the oblong opening, and

a fixation element configured to secure the coupling element, connector, and bone screw in a fixed position.

6. The bone screw apparatus of claim 5, wherein the fixation element is a locking screw, a cam lock, a taper lock, or an interference lock.

7. The bone screw apparatus of claim 5, further comprising an elongated locking wedge securing the coupling element and the polyaxial bone screw in a fixed position.

8. The bone screw apparatus of claim 7, wherein the elongated locking wedge comprises:

a posterior surface defining a connector channel thereon, and

an anterior surface defining an elongated concave channel extending substantially parallel with a major axis of the elongated locking wedge.

9. The bone screw apparatus of claim 8, wherein the connector channel is configured to accept the connector such that the posterior surface is in facing engagement with the connector.

10. The bone screw apparatus of claim 9, wherein the elongated concave channel is configured to contact the head of the bone screw.

11. The bone screw apparatus of claim 5, wherein the connector is a cylindrical rod, a square rod, an oval rod, a rectangular rod, or a hollow rod.

12. The bone screw apparatus of claim 5, wherein the oblong opening includes a plurality of notches defining a plurality of slot positions.

13. The bone screw apparatus of claim 10, wherein the oblong opening includes at least five slot positions.

14. The bone screw apparatus of claim 5, wherein the oblong opening is a continuous slot.

15. The bone screw apparatus of claim 5, wherein the oblong opening comprises at least one of a beveled edge and a rounded edge.

16. The bone screw apparatus of claim 5, wherein the bone screw apparatus comprises at least one additional polyaxial bone screw positioned within the oblong opening.

17. The bone screw apparatus of claim 16, wherein the polyaxial bone screws are posted polyaxial screws.

18. The bone screw apparatus of claim 5, wherein the polyaxial bone screw is a posted polyaxial screw.

19. The bone screw apparatus of claim 5, wherein the base includes:

a generally flat anterior surface; and

a generally flat posterior surface, and

wherein the oblong opening is formed by a substantially linear surface extending from the anterior surface to the posterior surface.

20. A bone screw system comprising:

a connector, and

at least two bone screw apparatuses each comprising:

a coupling element that includes:

an The bone screw apparatus of claim 5, wherein the oblong aperture extending extends through the coupling element and is configured to receive the connector in a plurality of positions about two dimensions within the aperture, and

a base having an oblong slot,

a polyaxial bone screw positioned within the oblong slot, and

a fixation element adjustably mounted to the coupling element that secures the coupling element, connector, and polyaxial bone screw to the coupling element in a fixed position.

21. A method for aligning and placing a bone screw system in bone, comprising:

(a) providing a bone screw system that includes;

a connector; and

at least a first and a second bone screw apparatus, wherein each bone screw apparatus has

a coupling element having

an aperture configured to allow the connector to be perpendicular to or at an angle relative to a plane extending generally parallel to the aperture; and

a base having an opening;

a bone screw positioned within the opening;

an elongated locking wedge for securing the coupling element and the bone screw in a fixed position; and

a fixation element that provides a securing force to the connector, the elongated locking wedge, and the bone screw,

wherein the connector extends through the aperture and wherein the fixation element is configured to secure the coupling element, elongated locking wedge, connector, and bone screw in a fixed position,

(b) positioning the first bone screw of the first bone screw apparatus in the opening of the first coupling element,

(c) screwing the first bone screw into bone,

(d) positioning the second bone screw of the second bone screw apparatus in the generally oblong opening of the second coupling element,

(e) screwing the second bone screw into bone,

(f) repositioning each of the first and second coupling elements relative to the first and second bone screws respectively, along the openings of the first and second coupling elements so as to align the first and second apertures of the first and second coupling elements;

(g) extending the connector through each of the aligned coupling elements and positioning the connector within the aperture of at least one of the first and second coupling elements perpendicular to or at an angle relative to the plane extending generally parallel to the aperture, and

(h) securing the alignment of the first bone screw apparatus and connector to the first bone screw by providing a securing force to the connector and the elongated locking wedge via the first fixation element, and

(i) securing the alignment of the second bone screw apparatuses and connector to the second bone screw by providing a securing force to the connector and the elongated locking wedge via the second fixation element.

22. A bone screw for attachment to a vertebra, comprising:

a housing having a rod passage for accepting a rod into the housing, the rod having a longitudinal rod axis;

a bone screw carried by the housing and positionable relative to the housing from a first side of the longitudinal rod axis when the rod is in the housing to a second side of the longitudinal rod axis, along a direction generally perpendicular to the longitudinal rod axis, the housing having a surface that is complementary in shape to a head of the bone screw;

a fixation element configured to secure the bone screw to the housing in various positions along the direction generally perpendicular to the longitudinal rod axis, wherein the fixation element is carried by the housing and is configured to secure both the rod and the bone screw to the housing; and

a member, the member restricted in movement in response to rotation of the fixation element against the rod for limiting relative movement between the bone screw and the housing.

23. The bone screw of claim 22, wherein the head of the bone screw is disposed in the housing.

24. The bone screw of claim 22, wherein the bone screw is adjustably positionable in various positions within the housing along the direction generally perpendicular to the longitudinal rod axis.

25. The bone screw of claim 22, wherein the member limits relative translational movement between the housing and the head of the bone screw.

26. A method of aligning and placing a bone screw system in bone, the method comprising:

providing an apparatus including a bone fastener having a head, a housing with an aperture extending therethrough in a first direction, and a connecting rod received in the aperture and passing through the housing;

engaging the bone fastener with a bone;

selectively adjusting the housing relative to the head of the fastener along a line perpendicular to the first direction; and

securing both the head of the fastener and the connecting rod relative to the housing with a fixation element,

wherein the housing includes an open upper end and the method further comprises passing the connecting rod along a plane from the open upper end toward a lower portion of the housing, and

wherein adjusting the housing relative to the head includes positioning the head from a first side of the plane to a second side of the plane.

27. A method of aligning and placing a bone screw system in bone, the method comprising:

engaging the bone fastener with a bone;

wherein securing both the head of the fastener and the connecting rod relative to the housing with a fixation element includes rotating the fixation element about an axis, the axis disposed in the plane.

28. The method of claim 27, wherein the apparatus further includes a member and the method further comprises limiting movement of the member in response to driving engagement of the fixation element against the connecting rod to thereby limit the head of the fastener relative to the housing.

29. An apparatus for a bone fixation procedure, the apparatus comprising:

a housing including an aperture extending through the housing in a first direction;

a connecting rod received in the aperture and passing through the housing;

a bone fastener including a head and an end adapted to engage a bone, the bone fastener carried by the housing such that the head of the bone fastener is adjustably positionable in various positions within the housing along a line perpendicular to the first direction prior to securing of the connecting rod to the housing, the housing having a surface that is complementary in shape to the head of the bone fastener; and

a fixation element carried by the housing for securing both the connecting rod and bone fastener relative to the housing,

wherein the housing includes an open upper end and a portion of the aperture proximate the open upper end defines a plane for passing the connecting rod from the open upper end toward a lower portion of the housing,

wherein the head of the bone fastener is disposed within the lower portion of the housing, and

wherein the head of the bone fastener is adjustably positionable from a first side of the plane to a second side of the plane.

30. An apparatus for a bone fixation procedure, the apparatus comprising:

a connecting rod received in the aperture and passing through the housing;

wherein the housing includes an open upper end and a portion of the aperture proximate the open upper end defines a plane for passing the connecting rod from the open upper end toward a lower portion of the housing, and

wherein the fixation element is rotatable relative to the housing about an axis, the axis disposed in the plane.

31. The apparatus of claim 30, further comprising a member, the member restricted in movement in response to rotation of the fixation element for limiting movement of the head of the bone fastener relative to the housing.

32. A method of aligning and placing a bone screw system, the method comprising:

providing an apparatus including a bone fastener including a head, a housing with an aperture extending therethrough in a first direction, and a connecting rod received in the aperture and passing through the housing;

engaging the bone fastener with a bone; and

selectively adjusting a location of the head of the fastener within the housing by moving the head of the fastener along a line perpendicular to the first direction,

33. A method of aligning and placing a bone screw system, the method comprising:

engaging the bone fastener with a bone; and

34. The method of claim 33, wherein the apparatus further includes a member and the method further comprises limiting movement of the member in response to driving engagement of the fixation element against the head of the fastener to limit movement of the head of the fastener relative to the housing.

35. A system for assisting in placement and alignment of a bone screw and for aligning bone, the system compromising:

an upper housing;

a lower housing;

a locking screw disposed within the upper housing, the locking screw engageable by a first tool for rotating the locking screw within the upper housing;

a connector inserted into the lower housing; and

a bone screw having a head located within the lower housing, the head of the bone screw able to be located at a plurality of different medio-lateral positions relative the lower housing, the bone screw engageable by a second tool to rotate the bone screw with respect to the bone, the lower housing defining a surface that is complementary in shape to the head of the bone screw,

whereby rotation of the locking screw by the first tool and rotation of the bone screw by the second tool secures the position of the upper housing, the lower housing and the connector with respect to the bone,

wherein the upper housing defines an aperture having an open upper end, the aperture proximate the open upper end defining a plane for passing the connector from the open upper end toward the lower housing, and

wherein at least a first position of the plurality of different medio-lateral positions is on a first side of the plane and at least a second position of the plurality of different medio-lateral positions is on a second side of the plane.

36. The system of claim 35, wherein the locking screw is rotatable by the first tool about an axis, the axis disposed in the plane.

37. The system of claim 35, further comprising a member, movement of the member relative to the housing being restricted in response to driving engagement of the locking screw against the connector for limiting movement of the head of the bone screw relative to the lower housing.

38. A bone screw apparatus comprising:

an upper housing;

a lower housing having a slot with a plurality of slot positions and including a center slot position;

a locking screw disposed within the upper housing;

a connector extending through the lower housing; and

a bone screw extending through the lower housing and being located at one of the plurality of slot positions, at least one of the plurality of slot positions being configured to inhibit movement of the bone screw along the slot,

wherein at least a first position of the plurality of slot positions is on a first side of the plane and at least a second position of the plurality of slot positions is on a second side of the plane.

39. A bone screw apparatus comprising:

an upper housing;

a locking screw disposed within the upper housing;

a connector extending through the lower housing; and

wherein the locking screw is rotatable relative to the upper housing about an axis, the axis disposed in the plane.

40. A system for assisting in placement and alignment of a bone screw and for aligning bone, the system compromising:

a first coupling element;

a second coupling element;

a connector inserted through the first coupling element and the second coupling element and connecting the first and second coupling elements;

a first bone screw having a head located within the first coupling element, the first coupling element having a first position relative to the first bone screw for permitting the first coupling element to slide with respect to the first bone screw and having a second position relative to the first bone screw for restricting movement of the first coupling element with respect to the first bone screw, the first coupling element having a first surface that is complementary in shape to the head of the first bone screw;

a second bone screw having a head located within the second coupling element, the second coupling element having a first position relative to the second bone screw to permit the second coupling element to slide with respect to the second bone screw and having a second position relative to the second bone screw for restricting movement of the second coupling element with respect to the second bone screw; and

a plurality of locking screws each disposed within one of the first and second coupling elements, each of the locking screws having a first position permitting the connector to move with respect to the one said locking screw, each of the locking screws having a second position locking movement of the connector with respect to the one said locking screw,

wherein the first coupling element defines an aperture having an open upper end, the aperture proximate the open upper end defining a plane for passing the connector from the open upper end toward a lower portion of the first coupling element, and

wherein the head is adjustable within the lower portion from a first side of the plane to a second side of the plane.

41. A system for assisting in placement and alignment of a bone screw and for aligning bone, the system compromising:

a first coupling element;

a second coupling element;

wherein the locking screw associated with the first coupling element is rotatable about an axis, the axis disposed in the plane.

42. A method for securing a connector to bone comprising:

driving a first bone screw having a head located within a first coupling element into the bone to a first position thereby permitting the first coupling element to slide with respect to the first bone screw;

driving a second bone screw having a head located within a second coupling element into the bone to a first position thereby permitting the second coupling element to slide with respect to the second bone screw;

selectively aligning the first and second coupling elements to receive a connector by sliding the first coupling element with respect to the first bone screw and sliding the second coupling element with respect to the second bone screw;

rotating a first locking screw located in the first coupling element into engagement with the connector to secure the connector with respect to the first coupling element; and

rotating a second locking screw located in the second coupling element into engagement with the connector to secure the connector with respect to the second coupling element,

wherein the first coupling element defines an aperture having an open upper end, the aperture proximate the open upper end defining a plane, and the method includes passing the connector along the plane from the open upper end toward a lower portion of the first coupling element, and

wherein aligning the first coupling element includes positioning the head of the first bone screw from a first side of the plane to a second side of the plane.

43. A method for securing a connector to bone comprising:

wherein rotating the first locking screw includes rotating the first locking screw about an axis, the axis disposed in the plane.

44. A system for assisting in placement and alignment of a bone screw and for aligning bone, the system compromising:

an upper housing;

a lower housing;

a connector inserted through the lower housing;

a bone screw having a head located within the lower housing, the head of the bone screw permitting pivotal and sliding movement of the lower housing with respect to bone screw when the lower housing is in an unlocked position relative to the bone screw, the head of the bone screw restricting pivotal and sliding movement of the lower housing with respect to bone screw when the lower housing is in an locked position relative to the bone screw, the lower housing defining a surface that is complementary in shape to the head of the bone screw;

a locking screw located within the upper housing; and

a tool for adjusting the position of the locking screw so as to cause the lower housing to move between an unlocked position relative to the bone screw and a locked position relative to the bone screw.

45. The system of claim 44, wherein the locking screw is rotatable relative to the upper housing about an axis, the lower housing movable relative to the head of the bone screw such that the head of the bone screw is positionable along the axis.

46. The system of claim 45, wherein the upper and lower housings cooperatively define an aperture for receiving the connector.

47. The system of claim 46, wherein a portion of the aperture defined by the upper housing allows the connector to be received by an open upper end of the upper housing and pass toward the lower housing.

48. The system of claim 47, wherein the portion of the aperture defined by the upper housing restricts movement of the connector during passing of the connector from the open upper end toward the lower housing to a plane.

49. The system of claim 48, further comprising a fixation element carried by the upper housing for securing both the connecting rod and bone fastener relative to the upper housing, the fixation element rotatable relative to the upper housing about an axis, the axis disposed in the plane.

50. The system of claim 44, further comprising a member, the member restricted in movement in response to rotation of the locking screw for limiting movement of the head of the bone screw relative to the lower housing.

51. An apparatus for coupling a bone screw to a connector comprising:

a housing that includes:

an aperture for receiving a connector, and a base having:

a generally flat anterior surface;

a generally flat posterior surface; and

a generally oblong opening formed by a substantially linear surface

extending from the anterior surface to the posterior surface;

a polyaxial bone screw movably engaged along the substantially linear surface forming the generally oblong opening; and

a fixation element adjustably mounted to the housing that engages both the connector and the polyaxial bone screw to secure both the connector and the polyaxial bone screw to the housing in a fixed position, wherein an upper portion of the housing includes a pair of spaced apart arms for threadably receiving the fixation element.

52. The apparatus of claim 51, wherein the pair of spaced apart arms define a plane for passing the connector from an open upper end of the housing toward a lower end of the housing.

53. The apparatus of claim 52, wherein the fixation element is coupled to the housing for rotation about an axis, the axis disposed in the plane.

54. The apparatus of claim 51, further comprising a member, the member restricted in movement in response to rotation of the fixation element against the connector for limiting movement of a head of the bone screw relative to the housing.

55. A bone screw system comprising:

a connector; and

at least two bone screw apparatuses, each bone screw apparatus comprising:

a coupling element that includes:

a base having an oblong slot; and

an oblong aperture configured to allow the connector to be perpendicular to or at an angle relative to a plane extending generally parallel to the oblong slot;

a polyaxial bone screw positioned within the oblong slot; and

a single fixation element adjustably mounted to the coupling element that secures the connector and polyaxial bone screw to the coupling element in fixed position, wherein the coupling element of at least one of the bone screw apparatuses includes a housing having an upper portion and a lower portion, the upper and lower portions cooperatively defining the oblong aperture such that the oblong aperture is open at an upper end thereof.

56. The bone screw system of claim 55, wherein the polyaxial bone screw includes a head, the base of the coupling element movable relative to the head.

57. The bone screw system of claim 55, further comprising a member, the member restricted in movement in response to rotation of the fixation element against the connector for limiting relative movement between the bone screw and the connector.

58. A bone screw system comprising:

at least two bone screw housings, each housing including:

a base having an oblong slot; and

an aperture perpendicular to a first plane extending generally parallel to the slot;

a polyaxial bone screw engageable relative to the oblong slot, at least one of the housings being movable relative to the polyaxial screw;

a connector positionably engaged within the aperture to allow a connector to be perpendicular to or at an angle relative to a plane extending generally parallel to the slot; and

a pair of fixation elements, with one of the fixation elements adjustably mounted to each of the housings to secure the connector and bone screw to the respective housing in fixed positions,

wherein the connector is received into the housing a first direction, the first direction being perpendicular to the first plane, and

wherein the housing is movable relative to a head of the polyaxial bone screw such that the head is adjustably positionable on both a first side of the first plane and a second side of the first plane.

59. The bone screw system of claim 58, wherein the connector has a longitudinal axis and further wherein the at least one of the housings is movable relative to the polyaxial screw in a direction perpendicular to the longitudinal axis.

60. The bone screw system of claim 58, wherein the polyaxial bone screw has a head, the head disposed in one of the bone screw housings.

61. The bone screw system of claim 58, further comprising a member, the member restricted in movement in response to rotation of the fixation element against the connector for limiting relative movement between the bone screw and the housing.

62. An apparatus for coupling a bone screw to a connector comprising:

a housing having an aperture and an oblong slot;

a polyaxial screw positionable within the oblong slot, the housing having a surface that is complementary in shape to a head of the polyaxial screw;

a connector positionably engaged within the aperture, the aperture being configured to allow the connector to be perpendicular to or at an angle relative to a plane extending generally parallel to the slot; and

means for fixing the connector that engages the polyaxial screw to secure both the connector and the screw in a fixed position along the oblong slot,

wherein the housing includes an upper portion and a lower portion that cooperate to define the aperture, the aperture being open at an upper end to receive the connector in a first direction such that a longitudinal axis of the connector translates within a plane as the connector moves from the upper end toward the lower portion of the housing, and

wherein the housing is movable relative to the head of the polyaxial screw such that the head is adjustably positionable on both a first side of the plane and a second side of the plane.

63. A system for coupling a bone screw to a connector comprising:

a housing having an oblong slot and an aperture, the oblong slot being substantially perpendicular to the aperture;

a polyaxial screw engaged within the oblong slot, the housing being independently adjustable in relation to the polyaxial screw and having a surface that is complementary in shape to a head of the polyaxial screw; and

means for fixing the housing in relation to the polyaxial screw along multiple positions relative to the oblong slot, the means for fixing disposed in the aperture in a plane substantially perpendicular or at an angle to the oblong slot,

wherein the housing is movable relative to a head of the polyaxial screw such that the head is adjustably positionable on both a first side of the plane and a second side of the plane.

64. A bone screw for attachment to a vertebra, comprising:

a housing having an upper portion, a lower portion, and a rod-receiving passage from the upper portion toward the lower portion, the rod-receiving passage having a plane along which a rod travels from the upper portion toward the lower portion;

a bone screw carried by the lower portion of the housing and movable from a first side of the plane to a second side of the plane, the housing having a surface that is complementary in shape to a head of the bone screw; and

a fixation element configured to secure the bone screw to the housing in various positions as the bone screw is moved between the first and second sides of the plane.

65. The bone screw of claim 64, wherein the bone screw translates from the first side to the second side in a direction generally perpendicular to the plane.

66. The bone screw of claim 64, further comprising a set screw received in the rod-receiving passage.

67. The bone screw of claim 64, wherein the head of the bone screw is disposed in the lower portion of the housing.

68. The bone screw of claim 66, further comprising a member, the member restricted in response to rotation of the set screw against the rod for limiting movement between the bone screw and the housing.

69. An apparatus for a bone fixation procedure, the apparatus comprising:

a connecting rod;

a housing including an oblong aperture extending therethrough in a first direction;

the connecting rod received in the oblong aperture and passing through the housing;

a bone fastener including a head and an end adapted to engage a bone, the bone fastener carried by the housing such that the head of the bone fastener is adjustably positionable in various positions along a line perpendicular to the first direction prior to securing of the connecting rod to the housing, the housing having a surface that is complementary in shape to the head of the bone fastener; and

wherein the housing includes an open upper end defining a rod-receiving passage through which the connecting rod passes within a plane from the open upper end toward a lower portion of the housing.

70. The apparatus of claim 69, wherein the head is movable relative to the housing from a first side of the plane to a second side of the plane.

71. The apparatus of claim 69, wherein the fixation element is a set screw received in the open upper end of the housing.

72. The apparatus of claim 69, wherein the open upper end of the housing includes a pair of spaced apart arms.

73. The apparatus of claim 69, further comprising a member, movement of the member relative to the housing is restricted in response to driving engagement of the fixation element against the connecting rod for limiting movement of the head of the bone fastener relative to the housing.

74. A bone screw for attachment to a vertebra, comprising:

a bone screw including a head that is carried by the housing and a shank that extends from the head, wherein the head of the bone screw is positionable relative to the housing from a first side of the longitudinal rod axis when the rod is in the housing to a second side of the longitudinal rod axis, along a direction generally perpendicular to the longitudinal rod axis, without rotating the shank of the bone screw about the head and without rotating the housing relative to the head of the bone screw; and

a fixation element configured to secure the bone screw to the housing in various positions along the direction generally perpendicular to the longitudinal rod axis.

75. The bone screw of claim 74 wherein, when the rod is in the housing, the head of the bone screw is movable from one side of the rod to another side of the rod without rotating the shank of the bone screw about the head.

76. The bone screw of claim 74, wherein the housing includes an upper housing defining the rod passage and a lower housing having a base which defines an opening that receives the head of the bone screw.

77. The bone screw of claim 76, wherein upper housing of the housing is immovably coupled to the lower housing of the housing.

78. The bone screw of claim 76, wherein the opening in the base of the lower housing is a slot having a length that extends along the direction generally perpendicular to the longitudinal rod axis.

79. A bone screw for attachment to a vertebra, comprising:

a bone screw including a head that is carried by the housing and a shank that extends from the head, wherein when the rod is in the housing, the head of the bone screw is translatable relative to the housing from a first side of the rod to a second side of the rod, along a direction generally perpendicular to the longitudinal rod axis; and

a fixation element configured to secure the bone screw to the housing in various positions as the head of the bone screw is translated between the first and second sides of the rod,

wherein the housing includes a base defining an opening that receives the head of the bone screw.

80. The bone screw of claim 79, wherein, when the rod is in the housing, the head of the bone screw is translatable from the first side of the rod to the second side of the rod without rotating the shank of the bone screw about the head.

81. The bone screw of claim 79, wherein the opening in the base of the housing is elongated in the direction generally perpendicular to the longitudinal rod axis to allow the head of the bone screw to translate from the first side of the rod to the second side of the rod.

82. The bone screw of claim 79, wherein the opening in the base of the housing has an edge that is complementary in shape to the head of the bone screw.