CN101166478A - Multiaxial anchoring assemblies and methods for spinal implants - Google Patents

Abstract

Systems and methods are provided that include a plate member (120, 140, 160, 180, 600) engageable to the spinal column with an anchor assembly (20, 320, 420, 520, 620, 720). The anchor assembly (20, 320, 420, 520, 620, 720) includes a coupling member (30, 130, 330, 430, 530, 630) having a post (32, 332, 432, 532, 632, 732) extending through at least one opening of the plate member (120, 140, 160, 180, 600) and an anchor member (70) pivotally captured in a receiver portion (34, 334, 434, 534, 634) of the coupling member (30, 130, 330, 430, 530, 630) below a lower surface of the plate member (120, 140, 160, 180, 600). A locking member (90, 590) secures the plate member (120, 140, 160, 180, 600) to the coupling member (30, 130, 330, 430, 530, 630). A crown (50, 150, 250, 350, 550, 650) in the receiver portion (34, 334, 434, 534, 634) of the coupling member (30, 130, 330, 430, 530, 630) is engaged by the plate member (120, 140, 160, 180, 600) to secure the anchor member (70) in position relative to the coupling member (30, 130, 330, 430, 530, 630).

Description

Multiaxial anchoring assemblies and methods for spinal implants

background

In the field of orthopedic surgery, especially spinal surgery, there has long been a need to attach an elongate element such as a plate or rod to bones in order to maintain and support them in a given position. For example, during surgery to fuse an injured, diseased, deformed or otherwise abnormal or damaged spine, the surgeon positions the spine in the correct position. An elongated plate is placed adjacent to one or more vertebral bodies and bone anchors such as screws or bolts are used to secure the plate to the vertebral bodies. Secure the anchor and plate to each other to minimize or prevent relative movement. In this way, the vertebral body will be held and/or supported in the correct position for healing.

There remains a need for systems, devices, and methods that facilitate positioning and attaching implants to one or more vertebrae of the spine, provide multiple ways of attaching implants to one or more vertebral bodies of the spine, and provide for The anchor assembly employed in the attachment of objects to one or more vertebrae of the spine has multi-axial capabilities.

Summary of the invention

The present invention relates to orthopedic implant systems and methods for stabilizing bony elements in desired spatial relationships in correcting bone misalignment, to provide fixation along one or more vertebral levels, or for spinal or other bony fusion. A multi-axial anchor assembly can be engaged to an implant, such as a plate element or rod element or other connector or implant, to secure the implant element to the bony structure.

According to one aspect, an anchor assembly is provided that includes an anchor element having a head and a lower portion extending from the head for engaging a bony element. The anchor assembly also includes a coupling element pivotally connected to the anchor head. The coupling element includes a lower receiving portion forming an inner receiving space for receiving the head and a stem portion extending away from the head below the receiving portion. The stem is configured to engage the locking element. The lower receiving portion forms at least one side wall opening in communication with the exterior of the coupling element. The anchor assembly also includes a crown positioned about the head of the anchor element in the receiving space of the coupling element. The crown includes a base portion in communication with the at least one sidewall opening for contacting the positioning of the implant element positioned about the stem of the coupling element to secure the implant element between the locking element and the base portion.

According to another aspect, a spinal board system is provided that includes an elongated board member including at least one opening extending therethrough between an upper surface and an opposing lower surface at the spine. The system also includes an anchor assembly engageable to the plate element. The anchor assembly includes a coupling member having a stem portion positionable through at least one opening, and a receiving portion including a receiving space positioned adjacent a lower surface of the plate member. The anchoring assembly includes an anchoring member whose head is pivotally received in the receiving space of the receiving portion and whose lower portion extends from the head for engaging the spinal bony structure. A crown is positioned adjacent the head in the receiving space and includes a base portion extending through the coupling element along the lower surface of the plate element. A locking member is engageable to the stem and positionable in contact with the upper surface of the plate member such that the lower surface of the plate member is in fixed contact with the base portion of the crown.

According to another aspect, there is provided a spinal board system comprising: an elongated board member extending along a longitudinal axis including at least one opening extending therethrough between an upper surface and a lower surface opposite the spine . The system also includes an anchor assembly engageable to the plate element. The anchor assembly includes a coupling element, the stem of which is positionable through the at least one opening and engageable to the plate element such that the coupling element is non-pivotable relative to the plate element. The coupling element comprises a receiving portion positionable along the lower surface of the plate element, the receiving space opening facing away from the plate element. The anchor assembly also includes an anchor element including a head pivotably received in the receiving space of the receiving portion. The anchoring element includes a lower portion extending from the head for engaging the bony structure of the spine. The anchoring element is pivotable relative to the plate element and the receiving portion when the stem portion is engaged to the plate element in the at least one opening.

According to one aspect, an anchor assembly is provided that includes an anchor element having a head and a lower portion extending from the head for engaging a bony element. The anchor assembly also includes a coupling element pivotally connected to the anchor head. The coupling element includes a lower receiving portion forming an inner receiving space for receiving the head and a stem extending from the receiving portion away from the head. The stem is configured to engage the locking element. The receiving portion forms a plurality of openings communicating with the exterior of the coupling element. The crown is positioned around the head of the anchoring element in the receiving space of the coupling element. The crown includes a plurality of axially extending base portions respectively extending through the plurality of openings. The base portion is positioned in contact with at least one implant element or a locking element positioned around the stem of the coupling element.

According to another aspect, a spinal board system is provided that includes an implant including at least one opening extending therethrough between an upper surface and an opposing lower surface positioned along a spinal column. The system also includes an anchor assembly engageable to the implant. The anchor assembly includes a coupling element having a stem portion positionable through the at least one opening and a receiving portion positioned toward the lower surface of the implant. The receiving portion includes a receiving space, and the rod forms a channel extending from a proximal end thereof to the receiving space. The anchor assembly also includes an anchor member including a head pivotally received in the receiving space of the receiving portion and a lower portion extending from the head for engaging the bony structure of the spine. The locking element may contact one of the upper surfaces of the implant or the receiving portion and engage the mounting portion of the stem to secure the implant to the spinal column.

According to another aspect, a spinal board system is provided that includes a board member having at least one opening extending therethrough between an upper surface and an opposing lower surface positionable toward the spine. The system also includes an anchor assembly engageable to the plate element. The anchor assembly includes a coupling member having a shank positionable through the at least one opening and a receiving portion positionable along the lower surface of the plate member. The stem is threadedly engaged with the receiving portion at the proximal opening of the receiving portion. The receiving portion includes a receiving space and an anchoring element including a head pivotally received in the receiving space of the receiving portion. The lower portion of the anchoring element extends from the head for engaging the bony structures of the spine. The locking element is engageable to the stem by contacting the upper surface of the plate element to secure the plate element to the coupling element between the locking element and the receiving portion.

According to another aspect, there is provided a method of spinal surgery, the method comprising: reaching at least one vertebra of the spine; engaging an anchoring element of an anchoring assembly to the at least one vertebra, the anchoring assembly comprising a coupling element, Its receiving portion is pivotally mounted around the head of the anchoring element, from which a stem extends proximally, and the receiving portion can be pivoted relative to the anchoring element; the stem and receiving portion are anchored relative to the engaged anchor The element is pivoted to a desired position; the elongated plate element is positioned near the proximal end of the stem; the plate element is advanced along the stem to a position adjacent to the receiving portion; The crown engages the plate element.

According to another aspect, there is provided a method of spinal surgery comprising: accessing at least one vertebra of the spine through an incision; engaging an anchoring element of an anchoring assembly to the at least one vertebra through the incision, the anchoring assembly Comprising a coupling element pivotably mounted to the anchoring element, a stem extending proximally from the anchoring element; pivoting the coupling element relative to the engaged anchoring element to orient the stem in a desired position; elongate Positioning the plate element near the proximal end of the stem; advancing the plate element along the stem to a position adjacent to the anchor element; engaging the plate element against a crown extending from the anchor in the coupling element and including a plurality of The base portion outside the coupling element, the plate element is positioned against the crown to secure the anchoring element in the coupling element.

These and other aspects are further described below.

Brief description of the drawings

Figure 1 is an exploded perspective view of a multi-axial anchor assembly.

Figure 2 is an exploded side view of the anchor assembly of Figure 1 .

3 is an assembled side view of the anchor assembly of FIG. 1 .

4 is an assembled side view of the anchor assembly of FIG. 1 rotated 90 degrees about its longitudinal axis from the orientation of FIG. 3 .

FIG. 5 is a top view of the anchor assembly of FIG. 4 .

6 is a cross-sectional view of a coupling element forming part of the anchor assembly of FIG. 1 .

7 is a cross-sectional view of a crown forming part of the anchor assembly of FIG. 1 .

Figure 8 is a perspective view of another embodiment of a crown.

Figure 9 is a cross-sectional view of a crown in another embodiment.

10 is a cross-sectional view of a locking element engageable with the coupling element of the anchor assembly of FIG. 1 .

11 is a cross-sectional view of the anchoring element of the anchoring assembly of FIG. 1 in a first embodiment.

12 is a cross-sectional view of an anchor element of the anchor assembly of FIG. 1 in another embodiment.

13 is a side view of a plate element secured to the multiaxial anchor assembly of FIG. 1 and a plate element secured to a uniaxial anchor with the locking element of FIG. 8 .

FIG. 14 is a cross-sectional view along line 14 - 14 of FIG. 13 .

Figure 15 is a plan view of a plate member of one embodiment.

Figure 16 is a side view of the plate element of Figure 15 .

FIG. 17 is a cross-sectional view along line 17-17 of FIG. 16 .

Figure 18 is a side view of the plate element of Figure 15 having a curved longitudinal profile.

Fig. 19 is a plan view of another embodiment plate member.

Fig. 20 is a plan view of another embodiment plate member.

Figure 21 is a perspective view of another embodiment of a plate member with a rod receiving portion.

Figure 22A is a side view of an instrument for grasping a plate element.

Figure 22B is a top view of the instrument of Figure 22A.

22C is an enlarged view of the distal gripping portion of the instrument of FIG. 22A in a first orientation.

Figure 22D is a side view of the instrument of Figure 22A with the grip portion in a second orientation.

22E is a top view of the instrument of FIG. 22A with the grip portion in a second orientation.

Figure 23 is an exploded side view of another embodiment of a multiaxial anchor assembly.

Figure 24 is a side view of the anchor assembly of Figure 23 .

Figure 25 is a side view of the anchor assembly of Figure 24 rotated 90 degrees about its longitudinal axis.

FIG. 26 is a cross-sectional view of the coupling elements making up the anchor assembly of FIG. 23 .

Figure 27 is an exploded side view of another embodiment of a multiaxial anchor assembly.

28 is a side view of the anchor assembly of FIG. 27. FIG.

Figure 29 is a side view of the anchor assembly of Figure 28 rotated 90 degrees about its longitudinal axis.

30 is a perspective view of another embodiment of a multi-axial anchor assembly engaged with a plate member.

FIG. 31 is an exploded view of the plate element and anchor assembly of FIG. 30 .

Figure 32 is a cross-sectional view of the plate element and anchor assembly of Figure 31.

33 is an exploded view of another embodiment of a multi-axial anchor assembly engaged with a plate member.

Figure 34 is a perspective view of the anchor assembly and plate element of Figure 33.

35 is an exploded view of another embodiment of a multi-axial anchor assembly engaged with a plate member.

Figure 36 is a perspective view of the anchor assembly and plate element of Figure 35 .

Description of the illustrated embodiment

In order to promote an understanding of the principles of the invention, reference will now be made to the embodiments illustrated herein and specific language will be used to describe the same. It should be understood, however, that this is not a limitation of the scope of the invention. Any changes and further improvements to the methods, systems and devices described, as well as further applications of the principles of the invention described herein, are contemplated as would normally be apparent to those skilled in the art to which this invention pertains.

A multi-axial anchor assembly is provided to secure an implant, such as a plate element or connector, to one or more spinal vertebrae. The anchor assembly includes an anchor element pivotally coupled in the receiving portion of the coupling element. The coupling element includes a stem extending proximally from the anchoring element for receiving the implant thereabout. The anchoring element is multi-directionally pivotable about the longitudinal axis of the assembly. In one embodiment, the coupling element is engageable such that the coupling element is restricted from pivoting in at least one direction relative to the implant, while the anchoring element is pivotable within the coupling element.

In one form, the coupling element includes a crown in the receiving portion that is extendable between the anchor and an element positioned around the stem. In one embodiment, the crown may rigidly engage the anchoring element in position relative to the coupling element when the locking element is secured against one of the implant or the crown. In another form, the coupling element includes at least one window and the crown includes a base portion extending through the at least one window to contact the lower surface of the implant positioned about the stem or the locking element. When the locking element is finally engaged with the anchor assembly, the locking element may securely engage one of the base portion or the implant against the base portion of the crown.

In another form, a multiaxial anchor assembly is provided that includes a coupling element for receiving an implant thereabout and an anchoring element extending distally from the coupling element. In one application of the plate element, before the coupling element is firmly engaged with the locking element, the coupling element is received in the elongated slot of the plate element so that it is not pivotable transversely to the longitudinal axis of the elongated slot, while the anchor can be moved along the opposite The coupling element pivots in all directions. Once the locking element is secured to securely engage the plate element to the coupling element, the coupling element and the anchoring element are secured to each other and relative to the plate element.

In another form, a multi-axial anchor assembly is provided that includes a link element and an anchor element pivotally mounted in a link element receiving portion. A stem extends proximally from the receiving portion and receives the locking element. The stem includes a mounting portion adjacent to the receiving portion to which the locking element is mountable to secure the implant to the coupling element or to engage the crown in the coupling element. An extension portion extends proximally from the mounting portion to facilitate placement of the implant about the stem. The extension portion can be removed from the mounting portion to minimize postoperative invasiveness of the anchoring assembly to adjacent tissue.

Referring now to FIGS. 1-5 , a multiaxial anchor assembly 20 is shown having a first orientation aligned along a longitudinal axis 21 . The anchor assembly 20 includes a coupling element 30 and an anchor element 70 pivotally engageable with the coupling element 30 by the clip 60 . The anchoring element 70 is pivotable about relative to the longitudinal axis 21 to its desired orientation. Crown 50 is received in coupling element 30 adjacent anchoring element 70 and includes at least a base portion extending outwardly from coupling element 30 through window 48 . Crown 50 is positionable against the lower surface of the plate element positioned around coupling element 30 and locking element 90 ( FIG. 10 ) is engageable to coupling element 30 to secure the plate element against crown 50 as shown in FIG. 14 . The downwardly or distally directed fixation force provided by the engagement of locking element 90 may also seat crown 50 on anchoring element 70 to rigidly engage anchoring element 70 in a desired position relative to coupling element 30 .

Further features of the coupling element 30 will now be described with reference to FIGS. 1-6 . Coupling element 30 includes a proximally extending stem portion 32 and a lower end receiving portion 34 centered on longitudinal axis 21 . The stem portion 32 is reduced in size relative to the receiving portion 34 such that the stem portion can pass through the plate member opening, while at least a portion of the receiving portion 34 is sized to prevent passage through the plate member opening. As shown in FIG. 6 , the coupling member 30 includes an upper end channel portion 42 extending through the stem portion 32 to communicate with a receiving space 44 formed in the receiving portion 34 . Receiving portion 34 includes an inner circumferential groove 46 adjacent receiving space 44 for receiving and retaining clip 60 therein.

The receiving portion 34 also includes at least one opening enabling the crown 50 to communicate with the outside of the coupling element 30 . In the embodiment shown, the coupling element 30 forms, on its opposite side, a window 48 communicating with the receiving space 44 . As further described herein, at least a portion of the crown 50 protrudes through the window 48 to contact a plate member positioned about the stem 32 . The crown 50 is dimensioned to protrude outwardly from the stem 32 such that plate elements positioned therearound are supported by the crown 50 . Also, as shown in FIG. 3, the shank 32 includes opposing flat surfaces 38 and opposing arcuate threaded portions 40 extending therebetween. As described below and shown in FIG. 14, the flats 38 can engage both sides of a slot or other opening in a plate member. In one embodiment, the stem 32 prevents twisting or rotation of the plate member about the stem 32 by engaging both sides of the elongated slot of the plate member. The threaded portion 40 can threadably engage a locking element 90 positioned about the stem portion 32 .

Upper channel portion 42 of shank 32 forms proximally open tool engagement channel 36 , the inner surface of which forms a non-circular cross-section configured to engage a tool to rotate coupling member 30 about longitudinal axis 21 . Additionally, channel portion 42 is sized to allow passage of a driving instrument to engage the anchoring element received in receiving portion 34 and apply driving force through coupling element 30 directly to the anchoring element.

Referring now to FIG. 7 , a cross-sectional view of crown 50 is shown. Crown 50 includes a base portion 52 having an arm 53 extending from a lower cup portion 54 . As shown in FIG. 1 , the base portion 52 is formed in an oval shape with a linear wall portion 57 extending between two arms 53 . Cup portion 54 includes a hemispherical shape projecting from base portion 52 , forming an opening at its lower or distal end 55 . The cup portion 54 defines a receiving space 58 having a concave curved inner surface adapted to receive the shape of the head of the anchoring element 70 located in the coupling element 30 . A through hole 56 extends through the base portion 52 and communicates with the receiving space 58 in the cup portion 54, allowing a driving instrument to be placed therethrough for engaging a tool pocket in the head of the anchor element 70 located in the receiving space 58 .

FIG. 8 shows another embodiment of a crown 250 having an upper or proximal base portion 252 and a lower or distal cup portion 254 . The cup portion 254 forms a receiving space that extends from the base portion 252 and opens distally on a side opposite to the base portion 252 . The head of the anchoring element 70 is received in the receiving space defined by the cup 254 . At least a portion of base portion 252 is formed by a pair of outwardly extending arms 253 extending proximally and distally along cup 254 . The through hole 256 extends through the base portion 252 and communicates with the receiving space defined by the cup portion 254 .

FIG. 9 shows another embodiment of a crown 350 , similar to crown 50 . Crown 350 includes an upper or proximal base portion 352 , a lower or distal cup 354 and a throughbore 356 . Arms 353 extend outwardly from cup 354 , including flange members 358 extending distally therefrom at the outer ends of both arms 353 , respectively. The distal end of each flange element 358 includes an inwardly facing lip 359 . In use, the lip 359 is supported on the window edge 49 of the coupling element 30 and the anchor element 70 is pivotally received in the receiving portion 34 . The flange member 358 and lip 359 can maintain a gap between the heads of the anchor member 70 positioned adjacent to the crown 350 such that when the plate member is secured against the base portion 352, the flange member 358 and lip 359 can maintain The gap between the head of the anchoring element 70 and the crown 350 enables the anchoring element 70 to pivot within the coupling element 30 . Crown 350 may be employed where dynamic stabilization of one or more vertebrae is desired. Dynamic stabilization may be provided by any one or combination of the following methods: removing the ridge 82 from the head of the anchoring element 70 (FIG. 11), providing a resilient crown, or maintaining a gap between the crown and the head of the anchoring element. .

FIG. 10 shows an embodiment of a locking element 90 engageable with the stem portion 32 of the coupling element 30 . The locking element 90 includes a body 92 having a sidewall 96 extending around a threaded throughbore 94 . The through hole 94 extends along a longitudinal axis 95 alignable with the longitudinal axis 21 of the anchor assembly 20 . A slot 98 extends through the side wall 96 and communicates with the through hole 94, dividing the locking member 90 into proximal and distal portions 91,93. When the locking element 90 is engaged around the stem 32 and the distal portion contacts the plate element 120 , as shown in FIG. 14 , further locking of the locking element 90 against the plate element deflects the proximal portion 91 towards the distal portion 93 . This provides a press fit or thread interlacing between the threads of the shank 32 and the threads of the locking element 90, preventing loosening of the locking element 90 in place. Other embodiments take other forms of locking element 90 including: locking elements without slots 98, locking elements with breakaway portions to ensure proper torque application during engagement, or locking elements that provide other engaging relationships with stem 32 , such as bayonet lock, press fit or fusion connections.

Figure 11 shows an anchoring element 70 in one embodiment. The anchoring element 70 includes an enlarged head 72 at its proximal end and a distal portion including a threaded rod 74 extending distally from the head 72 to a tapered distal tip 78 . Rod 74 includes a thread profile 76 extending therealong that is configured to engage bone tissue. Stem 74 and thread profile 76 may include any suitable shape, including: slots along all or a portion of stem 74 , and uniform or varying thread pitch, thread height, thread width, and shape along stem 74 . The thread profile 76 may be configured for insertion into a drilled or tapped hole, may be configured as a self-tapping thread, or may be configured as a self-drilling and self-tapping thread. Between the head 72 and the shank 74 is a non-threaded neck 80 , although the threads could extend along and/or beyond the neck 80 . Head 72 also includes a tool engaging pocket 84 open at its proximal end, which may have any suitable configuration for receiving a driving tool for applying a rotational driving force to anchoring element 70 and threadingly engages the bone tissue.

Head 72 includes a plurality of ridges 82 extending peripherally adjacent its proximal end, although head 72 without ridges 82 is also contemplated, as described above. For example, dynamic stabilization of the spinal column segment may be provided using an anchoring element having a smooth head that is rotatable within the crown 50 when the anchoring assembly is engaged to the plate element with the locking element 90 . As further described herein, the ridges 82 can engage or snap into the crown 50 to lock the anchor element 70 in place relative to the coupling element 30 when engaged to the plate element with the locking element 90 . The ridges 82 may be formed by a series of flat surfaces machined into the head 72 . Other embodiments contemplate forming the ridges from pins, knurling, teeth, or other surface features. Anchoring assembly 20 including an anchoring element having ridges 82 provides a rigid or static connection between the plate element and the spinal column segment.

As with any implant, the anchor assembly 20 is used to fully statically engage the implant to the spine by securing the anchor elements to the implant in rigid engagement with the respective coupling elements. Anchor assembly 20 can be used to fully dynamically engage any implant to the spine by securing anchoring elements pivotable within each coupling element to the implant. A combination of rigid and dynamic anchor assemblies 20 may also be employed to engage the implant to the spine.

Referring to FIG. 12 , another embodiment of the anchoring element 70 is shown in which the stem 74 has a lumen 86 extending longitudinally therealong, opening at the distal tip 78 and entering a tool engaging pocket 84 . Lumen 86 may be configured to receive a guide wire or other guiding element to guide placement of anchor 70 in a desired location relative to the bony structure. Lumen 86 may also be utilized to deliver bone graft or other bone growth promoting and/or therapeutic substances into the bone structure to which anchoring element 70 engages. Still other embodiments contemplate that the stem 74 includes one or more perforations or openings between the neck 80 and the distal tip 78 that communicate with the lumen 86 .

Still other embodiments contemplate anchoring element 70 including a distal portion having other configurations to engage bone tissue. For example, the distal portion may include cables, hooks, forceps, smooth rods with wings or bulbs, expandable anchors, bodies for positioning in intervertebral disc spaces, or other structures for engaging bony structures .

Referring now to FIG. 13 , engagement of the elongated plate member 120 to the vertebrae 24 , 26 on opposite sides of the disc space 28 with the multiaxial anchor assembly 20 and the uniaxial anchor 100 is shown. It should be understood that any combination of multiaxial and/or uniaxial anchor assemblies may be used to engage the plate member 120 to the vertebrae. The uniaxial anchor assembly 100 includes a threaded rod member 102 and a proximal head member 104 integrally formed with the threaded rod member 102 extending therefrom. The proximal head member 104 extends through the plate member 120 and includes a lower support member 108 against which the lower surface of the plate member 120 is positioned. The locking member 106 engages the head member 104 and clamps or seats the plate member 120 against the lower support member 108 .

FIG. 14 is a cross-sectional view also showing the connection of the plate element 120 to the multiaxial anchor assembly 20 . The plate element 120 is arranged such that its lower surface at least partially contacts the base portion 152 of the crown 150 . The stem 32 of the coupling element 130 extends through the plate element 120 and the locking element 90 is positioned around the stem 32 . As the locking element is advanced along the stem 32 towards the upper surface of the plate element 120 , the locking element 90 exerts a force against the plate element 120 and secures it securely between the base portion 52 of the crown 50 and the locking element 90 . In the illustrated embodiment, the fixation force pushes the crown 50 downwardly against the head 72 of the anchoring element 70 . In embodiments where rigid fixation is contemplated, the anchoring element 70 includes ridges 82 that snap into the crown 50 to lock the anchoring element 70 in place relative to the coupling element 30 and the plate element 120 .

Referring now to FIGS. 15-17 , further details of one embodiment of the plate member 120 are shown. Plate member 120 includes an elongated body 122 extending along a longitudinal axis 121 . The body 122 includes at least one opening in the form of an elongated slot 124 centered on and extending along the longitudinal axis 121 . The elongated slot 124 opens on upper and lower surfaces 125,127. Side rails 126 extend longitudinally along opposite sides of elongated slot 124 , and end rails 128 extend between side rails 126 at both ends of main body 122 .

The side rail 126 includes an inner surface 129 and an outer surface 131 that extend along the slot 124 . As shown in FIG. 17 , body 122 includes a longitudinal slot 130 in inner surface 129 extending along elongated slot 124 . The panel surfaces transitioning between the upper and lower surfaces and the inner and outer rail surfaces and the edges of the rails 126, 128 may be rounded or chamfered to eliminate any sharp edges or sharp transitions between panel surfaces.

In FIG. 18 , a plate element 120 is shown having a curved profile along its longitudinal axis 121 . The upper surface 125 is concave and the lower surface 127 is convex. This curved configuration can be provided by a pre-bent plate, or by the surgeon bending the plate during surgery to provide the desired fit to the patient's anatomy.

In Fig. 19, another embodiment of a plate element 140 is shown. Plate member 140 is similar to plate member 120 and includes an elongated body 142 having opposed side rails 146 and opposed end rails 148 . The plate member 140 includes openings in the form of a pair of elongated slots 144 , 145 formed along the main body 142 between which the central rail 150 extends between the side rails 146 . In the illustrated embodiment, the elongated slot 144 is shorter than the elongated slot 145 . Other embodiments contemplate long slots of equal length, and plate elements with more than two slots. As with any of the plate member embodiments, the slots may include dimples, pockets or other features for anchors to sit on or engage with. It is also contemplated that the plate member may include two or more slots adjacent to and extending along each other. Still other embodiments contemplate that the plate element has a plurality of openings in the form of circular holes between the upper and lower surfaces.

In Fig. 20, another embodiment of a plate element 160 is shown. Plate member 160 includes a body member 162 having side rails 166 and end rails 168 . A pair of end slots 165 are formed near the end rails 168 , and a middle slot 164 is formed between the end slots 165 . The middle rail 170 is located between the middle slot 164 and each end slot 165 . In the illustrated embodiment, the central slot 164 is longer than the end slots 165 .

In FIG. 21 , another embodiment of a plate element 180 is shown. Plate member 180 includes a body 182 having an anchor assembly engaging portion 184 and a rod receiving portion 188 . Anchor assembly engaging portion 184 includes an opening therethrough in the form of an elongated slot 186 for receiving an anchor assembly, such as anchor assembly 20 . The elongated slot 186 allows for adjustment of the positioning of the plate member 180 by securing the anchor assembly 20 in the elongated slot 186 . The rod receiving portion 188 forms a channel 190 for receiving an elongated spinal rod 196 therein. Channel 190 extends transverse to slot 186 . In the illustrated embodiment, the rod receiving portion 188 is a cylindrical member that completely surrounds the channel 190 . However, other embodiments are contemplated that the rod receiving portion 188 includes a plurality of members for clamping or gripping the rod in the channel 190 along all or part of its side-opening channel, and for receiving and/or engaging Other suitable arrangements of rods or other elongated implant elements.

22A-22E illustrate one embodiment of a plate gripper 200 , for example, engageable in slot 130 to grip a plate element for delivery to a surgical site. Examples of grasping instruments are described in US Patent Application Serial No. 10/202,918, filed July 25, 2002, the contents of which are incorporated herein by reference. The plate grip 200 includes a handle member 202 and a lever member 204 pivotably connected to the handle member 202 . The lever element 206 is connected to the lever element 204 with a first coupling 208 . Mounting rod 212 extends from handle member 202 through rod member 206 and includes locking member 210 having a proximal knob portion and a rod extending through mounting rod 212, as shown in FIG. 22C.

The distal end of the mounting rod 212 includes a mounting element 214 pivotally mounted thereto. The mounting member 214 includes an engaging portion 218 sized to fit within, for example, the elongated slot 124 of the plate member 120 . Engaging portion 218 may also be sized to fit within the opening or slot of any of the plate member embodiments described herein. In the illustrated embodiment, the engagement portion 218 includes an engagement member 220 to engage the slot 130 of the plate member 120 . Engagement element 220 may be in the form of a ball element or a stem that is recessable into engagement portion 218 to be positioned in slot 124 and then movable outward to engage slot 130 and mount plate element 120 to mounting element 214 . The locking member 210 is then rotated within the mounting rod 212 by its proximal knob so that the distal one of the engaging portions 218 can secure the engaging member 220 in an engaged position with the plate member.

The rod member 206 can be moved relative to the handle member 202 and the mounting rod 212 by moving the lever 204 between the open position shown in FIG. 22A and the closed position shown in FIG. 22D. Spring mechanism 222 generally biases lever member 204 and handle member 202 in the open position. In the open position, the orientation of the mounting element 214 enables the plate element to extend along an axis 203 ( FIG. 22C ), which is oriented more along the longitudinal axis 201 of the instrument 200 . In the closed position, a linkage 216 extending between the rod member 206 and the mounting member 214 pivots the mounting member 214 about the distal end of the mounting rod 212 when the rod member 206 is moved proximally with the lever 204 . In the closed position, the axis 203 and thus the plate element fixed to the mounting element 214 will extend perpendicular or substantially transverse to the longitudinal axis 201 of the instrument 200 . Thus, instrument 200 facilitates placement of a plate through a narrow incision or canal by grasping the plate in a first orientation, ie, along the path to the spine, and then remotely pivoting the plate into alignment with the spine.

Instrument 200 is but one example of a suitable instrument for grasping and delivering a plate member to the spine for engaging the anchoring assemblies described herein. Other examples of grasping instruments include tweezers or other grasping instruments, instruments with fasteners to engage the plate, and instruments that provide a press fit with the plate. For example, the instrument may engage in a slot or hole of the plate, clamp between the outer surfaces of the plate, or grip the plate between the surface of the slot or hole and the outer surface of the plate. Still other examples consider manually grasping the plate and delivering it to the surgical site.

Referring now to FIGS. 23-26 , another embodiment of a multiaxial anchor assembly 320 is shown. Anchor assembly 320 includes a coupling member 330 having a stem portion 332 extending along a longitudinal axis 321 of anchor assembly 320 . Stem portion 332 extends proximally along longitudinal axis 321 from receiving portion 334 a sufficient length to facilitate positioning of the implant about coupling element 330 and facilitate intraoperative assembly. The multiaxial anchor assembly 320 may also include a stem portion 332 having a removable proximal extension to provide a thin profile when implanted.

In the illustrated embodiment, the anchor assembly 320 includes an anchor member 70 that is pivotally received in the coupling member 330 with the clasp 60 . The crown 50 can be positioned in the coupling element 330 around the head 72 of the anchoring element 70 . The base portion 52 of the crown 50 is exposed through the coupling element 330 so that an implant, such as a plate element, received on the stem 332 and positioned against it can be locked using the locking element 90 described above in the anchor assembly 20. The lower surface of is fixed to the anchor assembly 320.

Coupling element 330 includes a receiving portion 334 at a lower or distal end of stem portion 332 . The receiving portion 334 includes a receiving space 344 for receiving the head 72 of the anchor member 70 therein, and an inner circumferential groove 346 for receiving the C-clip 60 . Clip 60 pivotally supports head 72 in receiving space 344 about which cup 54 of crown 50 is positioned such that at least a portion of base portion 52 extends through opposing window 348, as shown in FIG. 24.

The stem portion 332 includes a locking member mounting portion 333 and an extension portion 352 extending proximally from the mounting portion 333 . Extension portion 352 provides proximal extension of stem portion 332 along longitudinal axis 321 to facilitate placement of implant elements thereon and to guide the implant into position adjacent receiving portion 334 and crown 50 during surgery. Also, the extension 352 prevents slipping of the implant from the stem 332 during manipulation of the implant and vertebrae during surgery and prior to the engagement of the locking element 90 to the stem 332 . Additionally, locking element 90 may be temporarily engaged to stem 332 around extension 352, providing sufficient space between crown 50 and locking element 90 to secure the implant to anchor assembly 320 with locking element 90 during surgery. , operating the implant into position relative to the anchor assembly 230 .

The fracture region 350 is located between the mounting portion 333 and the extension portion 352 . As shown in FIG. 26, the fracture region 350 may be formed by an inwardly tapering wall portion in the shank 332, interrupting the thread profile along the shank 332 while also interrupting the surface forming plane 356 (FIG. 25). Tool engaging channel 336 extends through extension portion 352 and mounting portion 333 and includes a tool engaging surface forming a non-circular cross-section. There is a gauge portion 356 in the inner wall surface of the stem portion 332 adjacent to the fracture region 350 . Gauge portion 356 reduces the wall thickness of stem portion 332 adjacent fracture region 350 such that applying a predetermined level of torque to extension portion 352 in tool engagement channel 336 proximal fracture region 350 will sever extension portion 352 from mounting portion 333 . By varying the wall thickness of stem portion 332 at fracture region 350, the amount of torque required can be varied.

Extension 352 includes a tapered proximal end 358 to further facilitate placement of the plate member thereabout. The extension portion 352 includes opposing flat surfaces 356 and a threaded arcuate portion 354 extending between the two flat surfaces 356 . Similarly, mounting portion 333 includes opposing flat surfaces 338 and a threaded arcuate portion 340 extending therebetween, aligned with flat surface 356 and arcuate portion 354 of extension portion 352, respectively. Threaded arcuate portions 340 , 354 threadably receive and engage locking element 90 to stem portion 332 . The flats 338, 356 are sized to bear against the side walls along slots or other openings of the plate elements positioned thereon to eliminate sideways or pivoting of the plate elements. As the plate element is advanced along extension 352, coupling element 330 is further aligned relative to the opening of the plate element. In another embodiment, it is contemplated that the stem portion 332 is threaded along its entire length. In yet another embodiment, all or some of the stem portion 332 has no opposing flat surfaces, but instead has a circular cross-section. In another embodiment, the stem portion 332 is not threaded along the extension portion 352 .

Referring now to FIGS. 27-29 , another embodiment of a multiaxial anchor assembly 420 is shown. The anchor assembly 420 includes a coupling element 430 , the stem portion 432 of which extends along the longitudinal axis 421 of the anchor assembly 420 . Anchor assembly 420 may comprise any suitable configuration as described above with respect to anchor assemblies of other embodiments. Extended shaft portion 432 is similar to extended shaft portion 332 of polyaxial anchor assembly 320, but its length along longitudinal axis 421 enables its proximal end to be positioned adjacent to or extending through an incision or opening to the spinal column. Extended stem portion 432 facilitates positioning of the implant about coupling element 430 and guides the implant through the incision to a location adjacent the vertebral body where anchoring element 70 is engaged. Surgical instruments for grasping the implant can be eliminated, reducing crowding in the operating space created by the incision.

In the illustrated embodiment, the anchor assembly 420 includes an anchor member 70 that is pivotally received in the coupling member 430 with the clasp 60 . The crown 50 can be positioned in the coupling element 430 around the head 72 of the anchoring element 70 . The base portion 52 of the crown 50 is exposed or extended by the coupling element 430 such that the inferior surface of the implant can be secured thereagainst as described above for the anchor assembly 20 .

The coupling element 430 includes a receiving portion 434 at the lower or distal end of the stem portion 432 . Receiving portion 434 may be configured as described above with respect to receiving portions 34 and 334 . The stem portion 432 includes a locking element mounting portion 433 and an extension portion 452 extending proximally from the mounting portion 433 . The fracture region 450 is located between the mounting portion 433 and the extension portion 452 . Extension 452 provides a proximal extension of stem 432 to facilitate placement of an implant thereon and to guide the implant to a location adjacent crown 50 during surgery. Also, the extension 452 prevents the implant from slipping off the stem 432 during surgery and as the plate and vertebrae are manipulated prior to the engagement of the locking element 90 to the stem 432 . In addition, locking element 90 may be temporarily engaged to stem 432 around extension 452 to provide additional space for positioning between crown 50 and locking element before securing the implant to the anchor assembly with locking element 90 during surgery. 90 to manipulate the implant into position relative to the anchor assembly.

Similar to anchor assembly 320, stem portion 432 may have an internal tool pocket (not shown) extending through extension portion 452 and mounting portion 433, and a gauge portion in its inner wall surface adjacent fracture region 450 such that Application of a predetermined level of torque to extension 452 by the proximal end of 450 will sever extension 452 from mounting portion 433 .

Extension 452 includes a tapered proximal end 458 to further facilitate placement of the implant therearound. Extension portion 452 includes opposed flat surfaces 456 and a threaded arcuate portion 454 extending between flat surfaces 456 . Similarly, mounting portion 433 includes opposed flat surfaces 438 and a threaded arcuate portion 440 extending therebetween. Threaded arcuate portions 440 , 454 threadably receive and engage locking member 90 . The flats 438, 456 are sized to bear against the sidewall along an elongated slot or other opening of the implant positioned thereon to eliminate lateral movement or pivoting of the implant and to align the coupling element 430 relative to the implant.

Extended portion 452 facilitates rotation of coupling element 430 to properly align receiving portion 434 with the implant. Rotation of coupling element 430 may be a result of receiving tapered proximal portion 458 and self-aligning receiving portion 434 of the implant as the implant moves distally along extension portion 452 . The receiving portion 434 can also be rotated to a desired position relative to the implant by engaging the proximal portion 458 with a tool or manually.

As with any of the anchor assemblies of the embodiments described herein, with particular reference to anchor assemblies 320 , 420 , the stems 332 , 432 may be engaged with a constriction instrument to provide the mechanical advantage of positioning an implant, such as a plate element, adjacent to the crown 50 . The compression instrument may reduce the displacement between the misaligned vertebrae, or simply force the plate element into position adjacent the crown 50 before final fixation with the locking element 90 . Other embodiments contemplate constriction of the plate member and/or vertebrae by screwing the locking member 90 against the upper surface of the plate member to force the plate member closer to the crown 50 .

For example, a plate member may be positioned around the stem portion 332, 432 and the locking member may be temporarily engaged to the stem portion 332, 432 such that a portion of the threaded arcuate portion 354, 454 is exposed at the proximal end of the locking member. The constriction instrument may include a first member threadably engaged with the extension portion 352, 452 and a second member movable relative to the first member by an actuator. The second element can be positioned in contact with the plate element and the first element can be moved with an actuator lever to move the plate element along the stems 332 , 432 toward the crown 50 . The locking element 90 can then be advanced along the mounting portion 333, 433 to securely engage the plate element against the crown while the reduction instrument holds the plate element in the desired position relative to the anchor assembly.

30-32 illustrate another embodiment of a multiaxial anchor assembly 520 for securing an implant to one or more spinal vertebrae. Anchor assembly 520 includes anchor element 70 pivotally coupled in receiving portion 534 of coupling element 530 . Coupling member 530 includes a stem portion 532 extending proximally from a receiving portion 534 for receiving an implant, such as plate member 120 as shown, thereabout. When the stem 532 is positioned through the opening 124 of the plate 120 , the anchor member 70 can pivot relative to the plate member 120 . In one form, coupling element 530 includes a crown 550 positioned about stem portion 532 in receiving portion 534 extending between anchor element 70 and plate element 120 . In one embodiment, once the locking element 590 is secured against the plate element 120 , the crown 550 can rigidly engage the anchor element 70 in place relative to the coupling element 530 and the plate element 120 .

The coupling element 530 may include one or more windows providing a pathway for the crown 550 to communicate with the exterior of the coupling element 530 . In one embodiment, the coupling element 530 includes at least one window 548 and the crown 550 includes a base portion 552 that, when positioned about the stem 532, can be extended through the at least one window 548 to contact the plate. At least one axially extending arm 553 of the element 120 is formed. When the locking element 590 is positioned against the plate element 120 , the locking element 590 securely engages the plate element 120 against the one or more arms 553 of the crown 550 . In the illustrated embodiment, the coupling element 530 includes four windows 548 spaced therearound, and the crown 550 includes four arms 553 defining a base portion 552 that extend axially through the four windows 548, respectively. Other embodiments contemplate arrangements of two arms and windows, three arms and windows, or more than four arms and windows. The windows and arms may be evenly spaced from each other, or non-uniformly spaced. It is also contemplated that a particular anchor assembly may have a different number of arms and windows.

Multiaxial anchor assembly 520 includes a first orientation in which anchor element 70 and stem portion 532 are aligned along longitudinal axis 521 . Anchor assembly 520 also includes anchor element 70 pivotally engaged to coupling element 530 using retention clip 560 in the distal-facing opening of receiving portion 534 . The anchoring element 70 is multiaxial and is pivotally movable about the longitudinal axis 521 to an infinite number of positions relative thereto within a cone extending about the longitudinal axis 521 . In one embodiment, the angular range A defined by the cone from the axis 521 to the longitudinal axis 71 of the anchoring element 70 may be up to 90 degrees. In another embodiment, the angular range A is up to 45 degrees. In another embodiment, the angular range A is up to about 30 degrees.

Crown 550 is received in coupling element 530 adjacent anchoring element 70 and includes at least one base portion 552 extending outwardly from coupling element 530 through an aligned one of windows 548 . Locking element 590 is engageable to coupling element 530 to secure plate element 120 against crown 550 as shown in FIG. 32 . The downwardly or distally directed fixation force provided by the engagement of the locking element 590 can also seat the crown 550 on the proximal end of the anchoring element 70 to rigidly engage the anchoring element 70 in the desired position relative to the coupling element 530. in position.

Coupling element 530 includes a proximally extending stem portion 532 and a lower end receiving portion 534 centered on longitudinal axis 521 . The stem portion 532 has a relatively smaller size than the receiving portion 534 such that the stem portion 532 can pass through the opening of the implant while at least a portion of the receiving portion 534 is sized to prevent passage through the opening of the implant. The coupling member 530 includes an upper end channel portion 542 extending through the stem portion 532 in communication with a receiving space 544 formed in the receiving portion 534 . The receiving portion 534 includes an internally threaded profile 546 adjacent the receiving space 544 for threadingly receiving and engaging the retention clip 560 therein.

Retention clip 560 includes an externally threaded engagement portion 564 and a distal retention portion 562 . A lumen 566 extends through the engaging portion 564 and the retaining portion 562 and receives the threaded rod of the anchoring element 70 therethrough. As shown in FIG. 32 , lumen 566 includes a proximal portion sized to receive cup 554 of crown 550 therein, with the proximal end of anchoring element 70 positioned within cup 554 . Distal retaining portion 562 includes an inwardly radially extending flange 568 surrounding and contacting the head of anchoring element 70 extending distally beyond its maximum outer dimension to retain anchoring element 70 within coupling element 530 . The threaded engagement of the retention clip 560 with the coupling member 530 provides a secure coupled arrangement of the anchor member 70 in the lower end receiving portion 534 while facilitating assembly and disassembly of the anchor member 70 from the coupling member 530 without deforming or bending the retention clip 560.

Stem portion 532 may include a circular outer surface with an externally threaded profile to threadably engage locking element 590 . The stem portion 532 may also be configured to have opposing flats along its outer surface, as described above. Upper channel portion 542 of stem portion 532 forms a proximally open tool engagement channel 536 , the inner surface of which has a non-circular cross-section adapted to engage a tool to rotate coupling member 530 about longitudinal axis 521 . Additionally, channel portion 542 is sized to allow passage of a driving instrument to engage anchoring element 70 received in receiving portion 534 and apply a driving force directly to anchoring element 70 through coupling element 530 .

Crown 550 includes a base portion 552 positioned proximally of an inferior cup 554 . The base portion 552 includes a plurality of arms 553 extending axially therefrom with grooves formed between adjacent arms 553 . Base portion 552 includes an axially extending arm 553 sized to extend through and outwardly from window 548 relative to window 548 such that an implant positioned thereabout is at least partially supported by crown 550 . As shown in FIG. 31 , base portion 552 forms a proximally open cup shape with a central recessed region 557 and valleys 558 between arms 553 . Cup portion 554 includes a hemispherical body projecting distally from base portion 552, forming a distal-facing opening at its distal end. The cup portion 554 forms a receiving space 559 having a concave inner surface adapted to receive the shape of the proximal end of the anchoring element 70 positioned in the coupling element 530 . Through-hole 556 extends through base portion 552 and communicates with receiving space 559 , allowing a driving instrument to be placed therethrough to engage a tool pocket positioned in cup 551 proximal to anchoring element 70 .

30-32 illustrate one embodiment of a locking member 590 engageable to the stem portion 532 of the coupling member 530 . Locking member 590 includes a body 592 having a sidewall 596 extending around a threaded throughbore 594 . The through holes 594 may be aligned along the longitudinal axis 521 of the anchor assembly 520 . When the locking member 590 is engaged around the stem portion 532 and contacts the plate member 120, as shown in FIGS. any one or combination of the above. This in turn forces the crown 550 to sit on the head of the anchoring element 70 . For anchoring elements 70 with locking ridges, anchoring elements 70 may be rigidly connected to coupling elements 530 . Also contemplated are multiaxial coupling arrangements, as described above. Also, the configuration of the locking element 590 prevents it from loosening or dislodging along the stem 532 as described above with respect to the locking element 590 . Other embodiments contemplate other forms of locking element 590, including locking elements having breakaway portions to ensure proper torque application during engagement, or locking elements having other engaging relationships with stem 532, such as bayonet engagement, press fit, or fusion connect.

33-34 illustrate another embodiment of a multiaxial anchor assembly 620 to secure an implant, such as plate member 600, to one or more spinal vertebrae. In the illustrated embodiment, the plate member 600 includes a slotted connection portion 602 having a slot 604 . Other embodiments contemplate the connection portion 602 having no slot opening therethrough. The plate element 600 also includes a receiving portion 606 offset from the connecting portion 602 forming a receiving channel 608 . Receiving channel 608 is oriented transversely to slot 604 and is aligned to receive a rod or other elongate connecting element positioned along the spine when connecting portion 602 is engaged to a vertebra with an anchor in slot 604 . Through the receiving portion 606 there is a transverse lumen 610 in communication with the receiving passage 608 . A set screw or other engaging element may be positioned in lumen 610 to engage the elongated connector in channel 608 to secure the connector in position relative to anchor assembly 620 . It should be understood that anchor assembly 620 may be used with any of the embodiments of the plate element described herein, and that plate element 600 may be used with any of the embodiments of the anchor assembly described herein. It is also contemplated that anchor assembly 620 may be used to secure any type of implant to the bony structures of the spine.

Anchor assembly 620 includes anchor element 70 and locking element 590, as described above for anchor assembly 520, although other embodiments of anchors and locking elements are contemplated for use in anchor assembly 602. Anchor 70 is top-loaded and pivotally received in receiving portion 634 of coupling element 630 . Crown 650 may be positioned in receiving portion 634 proximal to the head of anchor 70 . Coupling element 630 also includes a stem portion 632 removably engaged to a proximal end of receiving portion 634 . In one embodiment, the crown 650 in the receiving portion 634 extends between the anchor element 70 and the plate element 600 positioned about the stem portion 632 . When the locking element 590 is secured against the plate element 600 , the crown 650 can rigidly engage the anchor element 70 in position relative to the coupling element 630 and the plate element 600 . Other embodiments contemplate limiting angular movement of the anchoring element 70 even after the locking element 590 is secured to the plate element 600 .

When the stem 632 is positioned through the opening 604 of the plate member 600 , the anchor member 70 can pivot relative to the plate member 600 . Various angular arrangements of the anchoring element 70 relative to the stem portion 632 are contemplated, as described herein with respect to other embodiment anchoring assemblies. Angular movement of anchoring element 70 relative to stem 632 facilitates positioning anchoring element 70 in the vertebrae in a desired orientation while allowing alignment of stem 632 to receive a plate element thereabout.

In one form, the stem portion 632 includes a distal engagement portion 660 extending radially outward around the distal end of the proximal stem portion 636 . The engagement portion 660 may have external threads to threadably engage internal threads at the proximal opening of the receiving portion 634 . In another form, the engaging portion 660 has internal threads to engage external threads on the receiving portion 634 . Other coupling arrangements are also contemplated, including friction or press fit, fusion, adhesives, fasteners, bayonet connections, snap fits, and the like. The engagement portion 660 includes at least one window 648, and the crown 650 includes a base portion 652 that, when positioned about the stem portion 632, can be extended by at least one shaft extending through the at least one window 648 to contact the plate member 600. Extending arm 653 is formed. When the locking element 590 is positioned against the plate element 600 , the locking element 590 securely engages the plate element 600 against the arms 653 of the one or more crowns 650 .

In the illustrated embodiment, the engagement portion 660 includes four windows 648 spaced about its circumference and is elongated circumferentially. The crown 650 includes four arms 653 defining a base portion 652 that extend axially through the four windows 648, respectively. Other embodiments contemplate designs with two arms and windows, three arms and windows, or more than four arms and windows. It is also contemplated that a particular anchor assembly may have a different number of arms and windows. Crown 650 is engageable with anchoring element 70 and configured in any of the various ways described above with respect to crown 550 .

Crown 650 is receivable in coupling element 630 adjacent anchoring element 70 and includes at least one base portion 652 extending outwardly from engagement portion 660 through one of windows 648, respectively. Locking element 590 is engageable to stem portion 632 to secure plate element 600 against crown 650 as shown in FIG. 34 . Locking element 590 is engageable to stem 632 to secure plate element 600 against crown 650 as shown in FIG. 34 . The downwardly or distally directed fixation force provided by the engagement of locking element 590 may also seat crown 650 on the proximal end of anchoring element 70 to rigidify anchoring element 70 relative to coupling element 630 and stem 632. Engage in desired position. In one embodiment, the crown 650 includes a lower end cup 654 whose outer surface contour conforms to the inner surface contour of the receiving portion 634, allowing the head of the anchoring element 70 to remain in the receiving portion at least until the locking element 590 is engaged against the implant. Pivot movement in part 634.

Coupling member 630 includes a lower end receiving portion 634 centered on longitudinal axis 621 , engaging portion 660 is engageable at a proximal end of receiving portion 634 , and stem portion 636 extends proximally therefrom along axis 621 . The stem portion 636 is reduced in size relative to the receiving portion 634 such that the stem portion 636 can pass through the opening of the plate member, while at least a portion of the engaging portion 660 and the receiving portion 634 are sized to prevent passage through the opening 604 of the plate member 600 . Stem portion 632 includes a circular outer surface with an externally threaded profile that threadably engages locking element 590 . The stem portion 632 may also be configured to have opposing flat surfaces along its outer surface, as described above.

Stem portion 632 may also form a proximal open tool engagement channel with an inner surface formed with a non-circular cross-sectional configuration for engaging a tool to rotate stem portion 636 and engagement portion 660 about longitudinal axis 621 . The passageway is sized to allow the passage of a driving instrument to engage the anchoring element 70 received in the receiving portion 634 and apply a driving force directly to the anchoring element 70 through the stem 632 .

Referring now to Figures 35 and 36, another embodiment of an anchor assembly 720, similar to the anchor assembly 620 described above, is shown. Anchor assembly 720 includes anchor element 70 pivotally received in coupling element 630 and crown 650 positioned adjacent the head of anchor element 70 , crown 650 extending axially through an axially extending window of engagement portion 760 . Stem 732 is similar to shank 632, but includes a shank portion 736 having a smooth, non-threaded outer surface extending along most of its length. In one form, the length of smooth portion 736 is sufficient to receive a connector that engages another spinal implant, such as a rod or tether. The distal end of the stem portion 732 includes a threaded profile 733 to threadably engage the locking element 590 .

Locking element 590 is engageable along thread profile 733 to position the distal end of body 592 in contact with the axially extending arm of crown 650 , securing anchoring element 70 in place as described above with respect to anchor assembly 620 . A connector or other implant may be engaged to stem 732 at the proximal end of locking element 590 . The connector may be secured in place by engaging the stem 732 with a set screw, clamping arrangement, friction fit, or other suitable coupling arrangement. Other embodiments contemplate that a second locking member may be engaged to stem portion 732 at the proximal end of the connector to clamp the connector between the locking members.

In one technique employing the anchoring assemblies described herein, the plate elements are sized to contact adjacent two vertebrae, including at least one opening adjacent the vertebrae, such that when the anchoring elements of the anchoring assembly engage the underlying bony structure , the coupling element of the anchor assembly can be placed through the at least one opening. In another embodiment, a locking element may be used to temporarily receive the anchor assembly on the plate element prior to engagement with the bony structure. The plate element can also be sized and configured to extend across more than two vertebrae for multilevel stabilization procedures, or it can be configured to engage one vertebra and the receiving element accepts an elongated connector that can be positioned along two or more vertebrae such as rods or plates.

The plate element may be pre-bent or bent during surgery to have a curved shape, eg, to reconstruct or conform to a natural or desired curvature of the spine. It should be understood that any curved shape suitable for one or more spinal segments (whether cervical, thoracic, lumbar or sacral) may be incorporated into the plate member. These curved shapes can include completely convex, completely concave, completely rectilinear (ie, substantially planar), and combinations thereof. It is also contemplated that the plate may be engaged to the anterior, bevel, lateral or posterior bony portion of one or more vertebrae.

The plate elements of the embodiments shown herein do not show retaining elements on or engageable to the plate elements to prevent or resist disengagement of the locking elements. However, the plate element may have one or more retaining elements to prevent dislodgement of any part of the anchor assembly relative to the plate element. The retaining element may be any one or combination of set screws, set screws and washers, spring loaded elements, sliding washers or other similar structures attached to, received on or integrally formed with the plate element.

A kit comprising any one or combination of one or more components of the implant assembly may be provided for ease of use. For example, a kit may include plate elements of different lengths, sizes, slot configurations, and/or curved shapes of some embodiments. Can include lengths and sizes for cervical, thoracic, lumbar, and/or sacral implants. One or more sets of multiaxial and uniaxial anchor assemblies are available in a variety of anchor element sizes and may be included in the kit for attachment to one or more cervical, thoracic, lumbar, sacral regions of the spine connection elements. The kit may also include a plurality of multi-axial anchor assemblies, including anchor assemblies configured to provide both rigid and dynamic stabilization of the spine when engaged with the plate element.

Methods of using one or more of the multiaxial anchor assemblies described herein are described below. The anchor assembly can be used in open surgery for retracting skin and tissue, for minimally invasive surgery in which one or more A minimally invasive access channel positions the anchor assembly and/or plate element within the patient's body.

In one procedure, the surgeon makes an incision in the patient relatively adjacent to the vertebrae or other bone to which the implant is to be attached. After obtaining proper access to the surgical site, the portion of the underlying vertebrae to be instrumented (eg, the pedicle) is processed in a standard manner. For example, an awl or drill can be used to open the hole, then probed for depth and tapped for the anchoring element. An anchoring element is then inserted into the hole in the underlying vertebra to which the coupling element is engaged. Access to a portion of the superior vertebra to be instrumented (eg, the pedicle) is then obtained, either through the existing incision or through a separate incision. Mark the point on the superior vertebra where the implant will be attached and prepare the vertebra as described above. Another anchor assembly is engaged to the superior vertebra, at least one anchor assembly being a multiaxial anchor assembly. The at least one multi-axial anchoring assembly may be configured to provide rigidity or dynamic stabilization when engaged to the plate element, as described above. The above process can be repeated for any one or more vertebrae between the upper and lower vertebrae as needed.

The plate element is then inserted directly into the anchor assembly either through the incision or through the access tube or retractor. The shank of the at least one multiaxial anchor assembly coupling element is positioned through the opening of the plate element or through the bottom face load respectively. The orientation and axial position of the coupling element relative to the anchor element and the plate element can be adjusted. When the plate elements and anchor assemblies are in desired positions relative to each other and relative to the spine, the locking elements can be advanced to secure the respective anchor assemblies and plate elements in desired positions relative to each other. The fixed plate elements may be used to compress or separate the vertebrae and maintain them in this position prior to final fixation of the plate elements to the anchor assembly. It is also contemplated that one or more intervertebral disc spaces or posterior elements may be fused with any one or combination of bone graft, bone substance, and implant. For anchor assemblies employing coupling elements with extended stems, the extended portion of the stem may be removed after the plate is secured to the anchor assembly.

It should also be understood that the above-described embodiments should be constructed of materials suitable for implantation in a human or other body, which may include inert metals such as titanium or stainless steel. Other strong materials such as certain ceramics or plastics are also contemplated. Bioresorbable materials such as polylactic acid compounds may be used in conjunction with or as part of the aforementioned components. In one embodiment, the anchoring assembly utilizes a non-metallic plate. Engagement of the anchor assembly with the non-rigid plate includes at least partial flexibility to achieve flexible spinal stabilization, allowing at least limited movement at the level of the instrumented vertebra. Spinal motion can be enhanced by providing an anchor assembly that enables dynamic engagement of the plate member to the spine, as described above.

While the invention has been shown and described in detail in the drawings and described description, these are considered to be illustrative and not restrictive, it is to be understood that only preferred embodiments are shown and described, and protection is required to fall within the scope of the invention. All changes and improvements.

Claims (75)

1. An anchor assembly, said assembly comprising: An anchoring element comprising a head and a lower portion extending from said head for engaging a bone element; a coupling element pivotally connected to the head of the anchoring element, the coupling element comprising a lower receiving portion and a stem portion extending away from the head from the lower receiving portion, the lower receiving portion being formed to receive the an internal receiving space of the head, the stem portion is configured to engage the locking element, the lower receiving portion forms at least one side wall opening communicating with the outside of the coupling element; and a crown positioned in said receiving space of said coupling element around said head of said anchoring element, said crown comprising a base portion communicating with said at least one side wall opening for contacting the surrounding The stem portion of the coupling element is positioned relative to the implant element to secure the implant element between the locking element and the base portion. 2. The assembly of claim 1 wherein said lower portion of said anchoring element comprises a threaded rod. 3. The assembly of claim 2, wherein the anchoring element includes a non-threaded neck between the head and the threaded rod. 4. The assembly of claim 3, further comprising a clip positioned around said neck and extending between said coupling member and said head, said clip being sized to to prevent passage of the head therethrough to retain the anchoring element in the coupling element. 5. The assembly of claim 1, wherein the head includes a plurality of ridges extending therearound and oriented toward the crown. 6. The assembly of claim 5, wherein the plurality of ridges engage the crown when the locking element secures the implant element against the base portion, the ridges engaging the crown. The engagement between the spine and the crown prevents pivoting of the anchoring element relative to the coupling element. 7. The assembly of claim 1, wherein said base portion of said crown includes an arm extending therefrom, said at least one sidewall opening of said coupling element includes opposing windows, said The arms are respectively positioned through the opposing windows. 8. The assembly of claim 7, wherein said crown includes a cup extending from said base portion, said cup including said head for receiving said anchoring element at The acceptance space in it. 9. The assembly of claim 8, wherein the crown includes a through hole extending through the base portion into the receiving space of the cup. 10. The assembly of claim 1, wherein the shank includes external threads for threadingly receiving the locking member thereabout. 11. The assembly of claim 10, wherein the locking member includes a body having a wall extending around a central lumen, the central lumen receiving the stem when the locking member is engaged therewith , the wall including a slot in communication with the lumen extending therethrough transverse to the lumen. 12. The assembly of claim 1, wherein the shank includes opposing flat surfaces extending along a length thereof interconnected by opposing arcuate threaded surfaces. 13. The assembly of claim 1, wherein said stem portion forms an axial passageway in communication with said receiving space. 14. A spinal board system comprising: an elongate plate member comprising at least one opening extending therethrough between an upper surface and an opposite lower surface capable of being positioned along the spine; an anchor assembly engageable to the plate element, the anchor assembly comprising: a coupling element having a stem portion positionable through the at least one opening and a receiving portion positionable adjacent a lower surface of the plate element, the receiving portion comprising a receiving space; an anchoring element comprising a head pivotally received in said receiving space of said receiving portion and a lower portion extending from said head for engaging a spinal bony structure; a crown positioned adjacent the head in the receiving space, the crown including a base portion extending through the coupling element along the lower surface of the plate element; and A locking element engageable to the stem and positioned in contact with the upper surface of the plate member to secure the lower surface of the plate member in contact with the base portion of the crown. 15. The system of claim 14, wherein the coupling element includes at least one window through which the base portion protrudes. 16. The system of claim 14, wherein the coupling member includes opposing windows, and the base portion includes opposing arms extending through the opposing windows, respectively. 17. The system of claim 14, wherein the lower portion of the anchoring element comprises a threaded rod. 18. The system of claim 17, wherein the anchoring element includes a non-threaded neck between the head and the threaded rod. 19. The system of claim 18, further comprising a clip positioned around the neck and extending between the coupling member and the head, the clip sized to to prevent passage of the head therethrough to retain the anchoring element in the receiving space of the coupling element. 20. The system of claim 14, wherein the head includes a plurality of ridges extending therearound adjacent to the crown. 21. The system of claim 20, wherein the plurality of ridges engage the crown when the locking element secures the plate element against the base portion, the ridges The engagement with the crown prevents pivoting of the anchoring element relative to the coupling element. 22. The system of claim 21, wherein said crown includes a cup extending from said base portion, said cup including said head for receiving said anchoring element at The acceptance space in it. 23. The system of claim 22, wherein the crown includes a through hole extending through the base portion into the receiving space of the cup. 24. The system of claim 14, wherein the stem includes external threads extending therealong for threadingly receiving the locking member thereabout. 25. The system of claim 24, wherein said locking member comprises a body having a wall extending around a central lumen for receiving said stem, said wall including a slot transversely extending therethrough to the lumen, in communication with the lumen. 26. The system of claim 14, wherein said at least one opening of said plate member comprises an elongated slot. 27. The system of claim 26, wherein the plate member includes a rod receiving portion forming a channel extending transverse to the slot for receiving a rod therethrough. 28. The system of claim 14, wherein the plate member includes an arcuate profile along the upper and lower surfaces. 29. The system of claim 14, wherein the plate member includes a plurality of slots extending therealong. 30. A spinal board system comprising: an elongated plate member extending along a longitudinal axis comprising at least one opening extending therethrough between an upper surface and an opposite lower surface, said lower surface being positionable toward the spine; an anchor assembly engageable to the plate element, the anchor assembly comprising: a coupling element comprising a stem positionable through said at least one opening and capable of engaging said plate element such that said coupling element is non-pivotable relative to said plate element, said coupling element comprising a receiving portion located on said lower surface of the element, said receiving portion comprising a receiving space remote from said plate element opening; and an anchoring element comprising a head pivotally received in the receiving space of said receiving portion, said anchoring element comprising a lower portion extending from said head for engaging a spinal bony structure when said stem is in The anchoring element is pivotable relative to the plate element and the receiving portion when engaged in the plate element in the at least one opening. 31. The system of claim 30, wherein the anchor assembly comprises: a crown positioned in the receiving space of the coupling element adjacent to the head of the anchoring element, the crown comprising a base extending through the coupling element along the lower surface of the plate element seat portion; and A locking member engageable to the stem and positioned in contact with the upper surface of the plate member such that the lower surface of the plate member is secured in contact with the base portion of the crown. 32. The system of claim 31, wherein the coupling element includes opposing windows opening into the receiving space, the base portion of the crown extending through the windows. 33. The system of claim 31 , wherein the anchoring element is non-pivotably engaged in the receiving portion when the locking element is positioned in contact with the upper surface of the plate element, to securely engage the lower surface of the plate element against the base portion, thereby engaging the crown against the head of the anchor element. 34. The system of claim 33, wherein the crown includes a cup extending from the base portion, the cup forming a receiving space for receiving the anchor member. The head of the anchoring element includes a plurality of ridges for engaging the cup to non-pivotably secure the anchoring element in the coupling element. 35. The system of claim 31 , wherein the locking member is positioned in contact with the upper surface of the plate member to securely engage the plate member against the base portion of the crown The lower surface of the anchor element is pivotable in the coupling element. 36. The system of claim 30, wherein said opening of said plate member comprises at least one elongated slot along said longitudinal axis of said plate member. 37. The system of claim 30, wherein the plate member is curved along the longitudinal axis such that the upper surface is concave and the lower surface is convex. 38. The system of claim 30, wherein the plate member includes a rod receiving portion forming a channel for receiving the elongate rod. 39. The system of claim 38, wherein the at least one opening is an elongated slot extending transverse to the channel. 40. The system of claim 30, wherein the lower portion of the anchoring element comprises a threaded rod. 41. The system of claim 40, wherein the anchoring element includes a lumen extending from the head through the distal tip of the threaded rod. 42. The system of claim 41, wherein the head includes a tool engaging pocket in communication with the lumen. 43. The system of claim 30, wherein the coupling element includes an internal passage extending axially through the stem in communication with the receiving space. 44. The system of claim 43, wherein at least a portion of the channel is configured to engage a driving tool. 45. The system of claim 43, wherein said head of said anchoring element includes a tool engaging pocket in communication with said receiving space. 46. The system of claim 45, wherein the anchoring assembly includes a crown positioned in the receiving space around the head of the anchoring element, the crown including a The channel of the coupling element and the tool engaging pocket of the anchoring element are aligned through holes. 47. A method of spinal surgery, said method comprising: reaches at least one spinal vertebra; engaging an anchoring element of an anchoring assembly to the at least one vertebra, the anchoring assembly comprising a coupling element having a receiving portion pivotally mounted around the anchoring element head and a proximally extending portion extending from the receiving portion stem; pivoting the receiving portion about the head of the anchoring element to the desired position, thereby moving the stem; positioning an elongated plate member about the proximal end of the stem; advancing the plate member along the stem to a position adjacent the receiving portion; and The plate element is engaged externally of the coupling element against a crown extending from the head of the anchor element through the coupling element to engage the plate element. 48. The method of claim 47, wherein the engaging plate element is engageable with the crown against the head of the anchoring element. 49. The method of claim 48, wherein engaging the plate element against the crown rigidly connects the coupling element to the anchoring element. 50. The method of claim 47, wherein the coupling element is pivotable relative to the anchoring element when the plate element is engaged against the crown. 51. An anchoring assembly comprising: an anchoring element comprising a proximal end and a distal portion extending from said proximal end for engaging a bone element; a coupling element pivotally connected to the proximal end of the anchor, the coupling element extending along a longitudinal axis comprising a lower receiving portion and a stem extending from the receiving portion away from the proximal end along the axis , the lower receiving portion forms an inner receiving space extending around the axis for receiving the proximal end, and the coupling element forms at least one axially extending window communicating with the outside of the coupling element; an element engageable to the stem; and a crown positioned in the receiving space of the coupling element adjacent the proximal end of the anchoring element, the crown including an axially extending base portion communicating with the at least one window for The element is positioned contactingly engaged to the stem of the coupling element. 52. The assembly of claim 51 wherein said stem portion includes an internal passage extending along said longitudinal axis in communication with said receiving space of said receiving portion. 53. The assembly of claim 51, wherein said anchoring element comprises a threaded rod along said distal portion and an enlarged head at said proximal end. 54. The assembly of claim 53, further comprising a retention clip positioned about the neck and extending between the coupling member and the head, the retention clip comprising a threaded portion that threadably engages the coupling element around a distally oriented opening of the receiving space, the retaining clip including a radially inwardly extending flange extending around the head of the anchoring element , which is dimensioned to prevent the passage of the head therethrough to retain the anchoring element in the coupling element. 55. The assembly of claim 53, wherein the head includes a plurality of ridges extending therearound oriented toward the crown. 56. The assembly of claim 55, wherein said plurality of ridges engage said crown when said element is secured against said base portion, said ridges engaging said crown The engagement therebetween prevents pivoting of the anchoring element relative to the coupling element. 57. The assembly of claim 51, wherein the stem is smooth along a majority of its length. 58. The assembly of claim 57, wherein said stem portion includes a threaded profile adjacent its distal end, said element being a lock capable of contacting said base portion threadedly engaging said threaded profile. 59. The assembly of claim 51, wherein said base portion of said crown includes a plurality of axially extending arms and said at least one window of said coupling element includes a plurality of axially extending arms. windows, the plurality of arms are respectively positioned through the plurality of windows. 60. The assembly of claim 59, wherein the crown includes a distal open cup extending from the base portion, the cup including a receiving space for receiving the anchoring element The proximal end is in it. 61. The assembly of claim 59, wherein the plurality of arms comprises at least three arms distributed around the circumference of the crown, and the plurality of windows comprises at least three arms distributed around the circumference of the coupling member. windows. 62. The assembly of claim 51, wherein the shank includes a circular cross-section and external threads thereabout for threadingly engaging the member. 63. The assembly of claim 51 , wherein the stem portion includes a distal engagement portion radially extending around a distal end of the threaded stem portion, the engagement portion threadably engaging a portion of the lower receiving portion. Proximal opening. 64. The assembly of claim 63, wherein said at least one window extends through said engagement portion of said stem. 65. A spinal implant system comprising: an implant comprising at least one opening extending therethrough between an upper surface and an opposing lower surface positioned toward the spine; An anchor assembly engageable to the implant, the anchor assembly comprising: A coupling element having a shank positionable through said at least one opening and a receiving portion positionable along said lower surface of said plate, said receiving portion comprising a receiving space and at least one in communication with said receiving space a window opening proximally, an anchoring element comprising a head pivotally received in said receiving space of said receiving portion and a distal portion extending from said head for engaging a spinal bony structure; a retention clip engageable to the coupling element in a distally oriented opening of the receiving space to pivotally receive the head in the receiving space; a crown positioned around the head of the anchor in the receiving space, the crown including at least one base portion extending through the proximally open window for contacting the implant object positioning; and A locking element engageable to the stem portion by contacting the implant to secure the implant to the coupling element by contacting the base portion. 66. The system of claim 65, wherein the stem portion includes an internal passage extending along the longitudinal axis in communication with the receiving space of the receiving portion. 67. The system of claim 65, wherein said retaining clip includes a threaded portion threadably engageable with said coupling element about said distally oriented opening of said receiving space, said retaining clip The buckle includes an inwardly radially extending flange extending around the head of the anchoring element and sized to prevent the passage of the head therethrough to retain the anchoring element in the coupling element . 68. The system of claim 65, wherein said base portion of said crown includes a plurality of axially extending arms and said at least one window of said coupling element includes a plurality of axially extending arms. windows, the plurality of arms are respectively positioned through one of the plurality of windows. 69. The system of claim 68, wherein the plurality of arms comprises at least three arms distributed around the circumference of the crown, and the plurality of windows comprises at least three arms distributed around the circumference of the coupling element. windows. 70. A method of spinal surgery, said method comprising: engaging an anchoring element of an anchoring assembly to at least one vertebra, the anchoring assembly comprising: a coupling element having a receiving portion forming a receiving space for receiving the anchoring element, a stem extending proximally from the receiving portion; and a crown in the receiving space adjacent a proximal end of the anchoring element, the crown including at least one proximally extending base portion extending from the receiving space to a location outside the receiving space; pivoting the coupling element relative to the engaged anchoring element to orient the stem in a desired position; advancing an element along the shaft to a position adjacent to the anchoring element; and The element is engaged against the at least one base portion of the crown to engage the crown in the receiving space to the proximal end of the anchor. 71. The method of claim 70, wherein the proximally extending base portion comprises a plurality of proximally extending arms of the crown, the coupling element comprising a corresponding number of crowns communicating with the receiving space. a proximally oriented window for receiving the respective arms therethrough. 72. The method of claim 71, wherein the plurality of arms comprises at least three arms and the plurality of windows comprises at least three windows. 73. The method of claim 70, wherein engaging the plate member includes rigidly securing an anchor member in the coupling member. 74. The method of claim 70, wherein the stem is threadably engageable to the receiving portion. 75. The method of claim 74, wherein the shaft portion includes a distal engagement portion extending radially outward from the proximal shaft portion, the distal engagement portion including a plurality of windows for receiving A plurality of arms extending proximally from the crown.

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