Low profile plate

[0001] The present application is a continuation-in-part application of U.S. application Ser. No. 14/341,035, filed Jul. 25, 2014, which is a continuation-in-part application of U.S. Ser. No. 14/320,200, filed Jun. 30, 2014, which is a continuation-in-part application of U.S. Ser. No. 14/190,948, filed Feb. 26, 2014, which is a continuation-in-part application of (i) U.S. Ser. No. 13/785,434, filed Mar. 5, 2013 and of (ii) U.S. Ser. No. 14/085,318, filed Nov. 20, 2013, which is a continuation-in-part application of U.S. patent application Ser. No. 13/785,856, filed Mar. 5, 2013, which is a continuation-in-part of U.S. patent application Ser. No. 13/559,917, filed Jul. 27, 2012, now issued as U.S. Pat. No. 8,961,606, which is a continuation-in-part of Ser. No. 13/267,119, filed Oct. 6, 2011, which claims priority to U.S. Provisional Application 61/535,726, filed on Sep. 16, 2011, the entire contents of which are incorporated by reference.

[0002] The present application is generally directed to orthopedic systems, and in particular, to systems including plates and spacers.

[0003] Spinal discs and/or vertebral bodies of a spine can be displaced or damaged due to trauma, disease, degenerative defects, or wear over an extended period of time. One result of this displacement or damage may be chronic back pain. In some cases, to alleviate back pain, the disc can be removed and replaced with an implant, such as a spacer, that promotes fusion. In addition to providing one or more spacers, a plating system can be used to further stabilize the spine during the fusion process. Such a plating system can include one or more plates and screws for aligning and holding vertebrae in a fixed position with respect to one another.

[0004] Accordingly, there is a need for improved systems involving plating systems and spacers for spinal fusion and stabilization.

[0005] Various systems, devices and methods related to plating systems are provided. In some embodiments, a spinal system comprises a spacer for inserting into an intervertebral space and a plate configured to abut the spacer. The spacer can include an upper surface, a lower surface and an opening that extends between the upper surface to the lower surface, wherein the spacer further includes a tapered leading end. The plate for abutting the spacer can include a plate body, a first opening formed in the plate body for receiving a first bone screw, a second opening formed in the plate body for receiving a second bone screw, a set screw, and a pair of extensions that extend from the plate body that are configured to engage the spacer. The first opening can angled in an upward direction, while the second opening can be angled in a downward direction. The set screw can be configured to prevent back-out of both the first and the second bone screws, wherein the set screw has a first position whereby the first and second bone screws can be inserted past the set screw and into the first and second openings and a second position following rotation of the set screw whereby the first and second bone screws are prevented from backing out by the set screw. A first bone screw is provided for inserting into the first opening in the plate body, wherein the first bone screw is configured to be inserted into a first vertebral body. A second bone screw is provided for inserting into the second opening in the plate body, wherein the second bone screw is configured to be inserted into a second vertebral body different from the vertebral body.

[0006] In other embodiments, a spinal system comprises a spacer for inserting into an intervertebral space and a plate configured to abut the spacer. The spacer can include an upper surface, a lower surface and an opening that extends between the upper surface to the lower surface, wherein the spacer further includes a concave leading end. The plate for abutting the spacer can include a plate body, a first opening formed in the plate body for receiving a first bone screw, a second opening formed in the plate body for receiving a second bone screw, a set screw, and a pair of extensions that extend from the plate body that are configured to engage the spacer. The first opening can angled in an upward direction, while the second opening can be angled in a downward direction. The set screw can be configured to prevent back-out of at least one of the first and the second bone screws, wherein the set screw has a first position whereby at least one of the first and second bone screws can be inserted past the set screw and into at least one of the first and second openings and a second position following rotation of the set screw whereby at least one of the first and second bone screws are prevented from backing out by the set screw. Each of the pair of extensions can include a window that extends along a length of the extension. A first bone screw is provided for inserting into the first opening in the plate body, wherein the first bone screw is configured to be inserted into a first vertebral body. A second bone screw is provided for inserting into the second opening in the plate body, wherein the second bone screw is configured to be inserted into a second vertebral body different from the vertebral body.

[0007] In some embodiments, a spinal system comprises a spacer for inserting into an intervertebral space and a plate configured to abut the spacer. The spacer can include an upper surface, a lower surface and an opening that extends between the upper surface to the lower surface. The plate for abutting the spacer can include a plate body, a first opening formed in the plate body for receiving a first bone screw, a second opening formed in the plate body for receiving a second bone screw, a set screw, and a pair of extensions that extend from the plate body that are configured to engage the spacer. The first opening can angled in an upward direction, while the second opening can be angled in a downward direction. The set screw can be configured to prevent back-out of at least one of the first and the second bone screws, wherein the set screw has a first position whereby at least one of the first and second bone screws can be inserted past the set screw and into at least one of the first and second openings and a second position following rotation of the set screw whereby at least one of the first and second bone screws are prevented from backing out by the set screw. Each of the pair of extensions can include a window that extends along a length of the extension. A first bone screw is provided for inserting into the first opening in the plate body, wherein the first bone screw is configured to be inserted into a first vertebral body. A second bone screw is provided for inserting into the second opening in the plate body, wherein the second bone screw is configured to be inserted into a second vertebral body different from the vertebral body. The spacer and the plate are independent from one another such that the spacer can be inserted into a desired spinal location prior to abutting the spacer with the plate.

[0040] The present application is generally directed to orthopedic systems, and in particular, to systems including plates and spacers.

[0041] The present application discloses orthopedic plating systems that can be used in spinal surgeries, such as spinal fusions. The plating systems disclosed herein include a plate and a spacer that are independent from one another. In some cases, the plate and the spacer can be pre-attached to one another before positioning them in a desired location of the spine. In other cases, the spacer can first be inserted into a desired location of the spine, and then the plate can be inserted thereafter. Advantageously, the plating systems disclosed herein are of low-profile. For example, they can provide a very small, anterior footprint cervical plate solution for fusion procedures. One skilled in the art will appreciate that while the plating systems can be used with cervical procedures, the plating systems are not limited to such areas, and can be used with other regions of the spine.

[0042] FIGS. 1A-1D illustrate different views of a plating system comprising a low profile plate attached to a spacer according to some embodiments. The plating system 5 includes a spacer 10 attached to a low-profile plate 50. Advantageously, the plating system 5 can be inserted through an anterior approach into a spine, and can desirably provide a small anterior footprint.

[0043] The spacer 10 is configured to have an upper surface 12, a lower surface 14, and a leading end 22. In some embodiments, the upper surface 12 and/or lower surface 14 includes texturing 16, such as teeth, ribs, ripples, etc. to assist in providing frictional contact with adjacent vertebral bodies. In some embodiments, the leading end 22 of the spacer 10 can be slightly tapered, as shown in FIG. 1A. With the taper, the leading end 22 can serve as a distraction surface that helps the spacer to be inserted into an intervertebral space. As shown in FIG. 1B, the leading end 22 can be concave, though in other embodiments, the leading end 22 can be straight or convex.

[0044] The spacer 10 can be substantially C-shaped (as shown in FIG. 3B), whereby it includes two side arms 13 that surround an inner opening 20. Adjacent the side arms 13 is a convex wall 19. In some embodiments, the convex wall 19 is substantially parallel to the concave surface of the leading end 22. The opening 20, which is configured to receive natural or synthetic graft material therein to assist in a fusion procedure, has an open side that is opposite convex wall 19, thereby giving the spacer 10 its C-shape.

[0045] The spacer 10 has a number of unique features that accommodate the attachment of a plate 50 thereto. Each of the side arms 13 of the spacer 10 includes a notch 17 (shown in FIG. 3B) for receiving a corresponding protrusion 71 of a lateral arm or extension 70 of the plate 50, thereby advantageously forming a first locking mechanism between the spacer 10 and the plate 50. In addition, in some embodiments, each of the side arms 13 of the spacer 10 can also include a hump region 26 (shown in FIG. 3B) that can extend in part into a window 72 of an attached plate 50 (shown in FIG. 2A), thereby advantageously providing a second locking mechanism between the spacer 10 and the plate 50. Advantageously, by providing secure first and second locking mechanisms between the spacer 10 and the plate 50, the plate and spacer will be kept securely together during any type of impaction of the plating system within the body. Furthermore, each of the side arms 13 of the spacer 10 can include a cut-away portion or chamfer 18, 19 (shown in FIG. 3C) to advantageously accommodate screws which pass through the plate. In embodiments that involve a pair of screws through the plate 50—one of which passes in an upward direction, and the other of which passes in a downward direction—one side arm 13 of the spacer 10 will include an upper chamfer 18 formed on an upper surface to accommodate the upwardly directed screw, while the second side arm 13 of the spacer will include a lower chamfer 19 formed on a lower surface to accommodate the downwardly directed screw.

[0046] The spacer 10 can be formed of any material. In some embodiments, the spacer 10 is formed of a polymer, such as PEEK, as shown in FIG. 3A. In some embodiments, the spacer 10 is formed of allograft bone, as shown in FIG. 4A. In some instances, to form an allograft implant, allograft bone may be cut or shaved from a desired bone member. The cut allograft bone will then be assembled together, using an adhesive or mechanical fastener (e.g., bone pins). Accordingly, in some embodiments, an allograft spacer 10 is formed of two, three, four or more layers that are assembled together, such as by one or more bone pins. One particular advantage of the invention is that the plate 50 can work with a variety of different spacers 10, as the plate 50 is independently removable from and attachable to the spacer 10. Regardless of whether a surgeon chooses to implant an allograft spacer or PEEK spacer 10 into an intervertebral space, the surgeon can simply attach the low-profile plate 50 to the spacer 10 following implantation into the intervertebral space.

[0047] The plate 50 is configured to have a plate body and a pair of lateral extensions 70 that extend from the plate body, each of which has a protrusion 71, for inserting into a corresponding notch 17 of the spacer 10. These lateral extensions 70 help form the first locking mechanism between the plate 50 and the spacer 10, as discussed above. In addition, the lateral extensions 70 of the plate 50 each include a window 72 (shown in FIG. 2A) for receiving a hump region 26 on the arms 17 of the spacer 10, thereby helping to form the second locking mechanism between the plate 50 and the spacer 10, as discussed above.

[0048] In addition to attaching to the spacer 10, the plate 50 is also configured to attach into one or more vertebral bodies via one or more bone screws. As shown in FIG. 1A, the plate 50 includes a first screw hole 52 and a second screw hole 54 for receiving bone screws therein. In some embodiments, screw hole 52 is angled upwardly such that an inserted bone screw passes upward into an upper vertebral body, while screw hole 54 is angled downwardly such that an inserted bone screw passes downward into a lower vertebral body. While the illustrated embodiment illustrates a pair of screw holes for receiving a pair of bone screws, it is possible to have one, three, four, five or more screw holes for receiving a different number of bone screws.

[0049] Over time, it is possible for bone screws to back-out. The plate 50 thus has a blocking or set screw 56 (shown in FIG. 1C) that assists in preventing back-out of inserted bone screws. As shown in FIG. 1C, the set screw 56 can be in an initial position that allows first and second bone screws to pass through holes 52, 54. Once the bone screws have been inserted through the holes 52, 54, the set screw 56 can be rotated (e.g., 90 degrees), to thereby block the bone screws and prevent back out of the bone screws. In some embodiments, the set screw 56 abuts a side of the head of the bone screws to prevent back-out of the bone screws, while in other embodiments, the set screw 56 rests over a top of the head of the bone screws to prevent back-out of the bone screws. In some embodiments, the set screw 56 comes pre-fixed with the plate 50. As shown in FIG. 1C, a single set screw 56 can be used to conveniently block a pair of bone screws. In other embodiments, each bone screw can be assigned its own set screw, which can operate independently of one another, to prevent back-out of the bone screw.

[0050] The plate 50 can also include one or more knife-like edges 63 that provide additional torsional stabilization when the plate 50 rests against a bone member. As shown in FIG. 1C, the knife-like edges 63 can be formed on both the upper and lower surfaces of the plate 50 body. While the illustrated embodiment shows a pair of knife-like edges 63 on an upper surface of the plate body and a pair of knife-like edges 63 on a lower surface of the plate body, one skilled in the art will appreciate that a different number of knife-like edges 63 can be provided.

[0051] FIGS. 2A-2D illustrate different views of the low profile plate shown in FIGS. 1A-1D. From these views, one can see the pair of lateral extensions 70 that extend from the body of the plate 50. At the distal end of each of the lateral extensions 70 is an inwardly-facing protrusion 71 that is configured to fit into a corresponding notch in the spacer 10. In addition, from these views, one can see the windows 72 that are formed in each of the lateral extensions 70. The windows 72 advantageously receive hump regions 26 of the spacer to provide a locking mechanism, and also help to improve desirable radiolucency. Advantageously, the windows 72 can have rounded edges to accommodate the spacer 10 therein. While the illustrated windows 72 are shown as rectangular with rounded edges, in other embodiments, the windows 72 can have a different shape, such as circular or oval. In some embodiments, the plate 50 is assembled axially to the spacer 10.

[0052] In some embodiments, the low profile plate 50 can also include indented gripping sections 73 (shown in FIGS. 2A and 2B). These indented gripping sections 73 advantageously provide a gripping surface for an insertion instrument, thereby facilitating easy delivery of the plate to a spacer body during surgery.

[0053] FIGS. 3A-3D illustrate different views of a PEEK spacer to be used with the low profile plate shown in FIGS. 2A-2D. From these views, one can see how the spacer 10a includes an upper surface 12a and a lower surface 14a with texturing 16a; a generally C-shaped body including a pair of arms 13a each having a notch 17a formed therein and an upper chamfer 18a or lower chamfer 19a; and a tapered leading edge 22a. In addition, one skilled in the art can appreciate the substantially symmetric shape of the inner opening 20a, which serves as a graft hole for receiving graft material therein.

[0054] FIGS. 4A-4D illustrate different views of an allograft spacer to be used with the lower profile plate shown in FIGS. 2A-2D. While the allograft spacer 10b shares similar features to the PEEK spacer 10a shown in previous figures, such as the notches 17b, hump surfaces 26b, and chamfers 18b,19b, the allograft spacer 10b need not be the same. For example, the shape of the graft opening 20b can be more of an arch, as shown in FIG. 4B.

[0055] FIGS. 5A-5D illustrate different views of a second alternative embodiment of a low profile plate attached to a spacer according to some embodiments. Rather than having a plate 50 with lateral extensions 70 that extend around the outer surface of a spacer 10, the present embodiment of the plating system 105 includes a plate 150 with an enclosed posterior extension 155 that fits within the body of the spacer 110. The enclosed posterior extension 155 includes extending surfaces 166, 167 that are fitted into corresponding inlets 121, 123 formed in the body of the spacer 120, thereby forming a first locking mechanism between the plate 150 and the spacer 110. In addition, the enclosed posterior extension 155 of the plate 50 includes one or more deformable locking tabs 160 (shown in FIG. 6B) that securely lock into tab holes 181a in the spacer body 110, thereby forming a second locking mechanism between the plate 150 and the spacer 110. While in some embodiments, the plate 150 can be attached to the spacer 110 after inserting the spacer 110 into a desired location in the body, in other embodiments, the plate 150 can be pre-assembled with the spacer 110 prior to inserting the plating system 105 into the desired location.

[0056] Like the spacer 10 in FIG. 1A, the spacer 110 is configured to have an upper surface 112, a lower surface 114, and a leading end 122. In some embodiments, the upper surface 112 and/or lower surface 114 includes texturing 116, such as teeth, ribs, ripples, etc. to assist in providing frictional contact with adjacent vertebral bodies. In some embodiments, the leading end 122 of the spacer 110 can be slightly tapered, as shown in FIG. 7D. With the taper, the leading end 122 can serve as a distraction surface that helps the spacer 110 to be inserted into an intervertebral space. As shown in FIG. 1B, the leading end 122 can be concave, though in other embodiments, the leading end 122 can be straight or convex.

[0057] The spacer 110 can be substantially C-shaped (as shown in FIG. 7B), whereby it includes two side arms 113 that surround an inner opening 120. Adjacent the side arms 113 is a straight wall 119 that forms the border of the graft opening 120. The straight wall 119 can include one or more tab holes 181 (shown in FIG. 7A) for receiving deformable tab locks 160 therein. The graft opening 20, which is configured to receive natural or synthetic graft material therein to assist in a fusion procedure, has an open side that is opposite the straight wall 119, thereby giving the spacer 110 its C-shape.

[0058] In some embodiments, the graft opening 120 (shown in FIG. 7B) has a different shape from the opening 20 of the spacer 10 of the prior embodiment, as the graft opening 120 is configured to not only receive graft material, but also the enclosed posterior extension 155 of the plate 150. For example, the graft opening 120 includes two inlets—a first inlet 121 formed at the junction between the first arm 113 and wall 119 and a second inlet 123 formed at the junction between the second arm 113 and wall 119 (shown in FIG. 7B)—for receiving outwardly extending surfaces 166, 167 of the plate 150 (shown in FIG. 6B). In addition, the graft opening 120 includes two outwardly tapering walls 111 that provide enough space to accommodate any bone screws inserted in the plate 150. As such, additional chamfers 18, 19 (as shown in FIG. 3B) are optional.

[0059] Like spacer 10, the spacer 110 can be formed of a variety of materials. In some embodiments, the spacer 110 comprises PEEK, as shown in FIG. 7A, while in other embodiments, the spacer 110 comprises allograft bone, as shown in FIG. 8A.

[0060] The plate 150 is configured to have a plate body, and an enclosed posterior extension 155 that extends from the plate body, which is received within and retains the spacer 110. The enclosed posterior extension 155 includes first and second outwardly extending surfaces 166, 167 that fit into inlets 121, 123 formed within the spacer 110 body to form a first locking mechanism. In addition, one or more deformable tab locks 160 extend from an exterior surface of the enclosed posterior extension 155 and are received in corresponding tab holes 181 in the spacer 150 to form a second locking mechanism. In some embodiments, the side walls of the enclosed posterior extension 155 can include one or more windows 172 (shown in FIG. 6A) for improving radiolucency of the plating system. In some embodiments, the plate 150 is assembled axially to the spacer 110.

[0061] In addition to attaching to the spacer 110, the plate 150 is also configured to attach into one or more vertebral bodies via one or more bone screws 88, 89. As shown in FIG. 5A, the plate 150 includes a first screw hole 152 and a second screw hole 154 for receiving bone screws 88, 89 therein. In some embodiments, screw hole 152 is angled upwardly such that an inserted bone screw 88 passes upward into an upper vertebral body, while screw hole 154 is angled downwardly such that an inserted bone screw 89 passes downward into a lower vertebral body. While the illustrated embodiment illustrates a pair of screw holes for receiving a pair of bone screws, it is possible to have one, three, four, five or more screw holes for receiving a different number of bone screws.

[0062] Over time, it is possible for bone screws to back-out. The plate 150 thus has a blocking or set screw 156 (shown in FIG. 5C) that assists in preventing back-out of inserted bone screws. As shown in FIG. 5C, the set screw 156 can be in an initial position that allows first and second bone screws to pass through holes 152, 154. Once the bone screws have been inserted through the holes 152, 154, the set screw 156 can be rotated (e.g., 90 degrees), to thereby block the bone screws and prevent back out of the bone screws. In some embodiments, the set screw 156 abuts a side of the head of the bone screws to prevent back-out of the bone screws, while in other embodiments, the set screw 156 rests over a top of the head of the bone screws to prevent back-out of the bone screws. In some embodiments, the set screw 156 comes pre-fixed with the plate 150. As shown in FIG. 5C, a single set screw 156 can be used to conveniently block a pair of bone screws. In other embodiments, each bone screw can be assigned its own set screw, which can operate independently of one another, to prevent back-out of the bone screw.

[0063] The plate 150 can also include one or more knife-like edges 163 that provide additional torsional stabilization when the plate 150 rests against a bone member. As shown in FIG. 5C, the knife-like edges 163 can be formed on both the upper and lower surfaces of the plate 150 body. While the illustrated embodiment shows a pair of knife-like edges 163 on an upper surface of the plate body and a pair of knife-like edges 163 on a lower surface of the plate body, one skilled in the art will appreciate that a different number of knife-like edges 163 can be provided.

[0064] FIGS. 6A-6D illustrate different views of the low profile plate shown in FIGS. 5A-5D. From these views, one can see the enclosed posterior extension 155 that extends from the body of the plate 150. At the distal end of the enclosed posterior extension 155 are a pair of outwardly extending surfaces 166, 167 that are configured to fit within inlets 121, 123 formed in the spacer. From these views, one can also see the deformable tab lock 160 (FIG. 6B) that can help secure the plate 150 to the spacer 110. In addition, from these views, one can see the windows 172 that are formed in each of the arms of the enclosed posterior extension 155. The windows 172 advantageously help to improve desirable radiolucency, and are of large size to provide a large viewing surface area. While the illustrated windows 172 are shown as triangular with rounded edges, in other embodiments, the windows 172 can have a different shape, such as circular or oval. In some embodiments, the plate 150 is assembled axially to the spacer 110.

[0065] In some embodiments, the low profile plate 150 can also include indented gripping sections 173 (shown in FIGS. 6A and 6B). These indented gripping sections 173 advantageously provide a gripping surface for an insertion instrument, thereby facilitating easy delivery of the plate to a spacer body during surgery.

[0066] FIGS. 7A-7D illustrate different views of a PEEK spacer to be used with the low profile plate shown in FIGS. 5A-5D. From these views, one can see how the spacer 110a includes an upper surface 112a and a lower surface 114a with texturing 116a; a generally C-shaped body including a pair of arms 113a each having an inner inlet 121, 123a formed therein; and a tapered leading edge 122a. In addition, one skilled in the art can appreciate the substantially symmetric shape of the inner opening 120a, which serves as a graft hole for receiving graft material therein.

[0067] FIGS. 8A-8D illustrate different views of an allograft spacer to be used with the lower profile plate shown in FIGS. 5A-5D. While the allograft spacer 110b shares similar features to the PEEK spacer 110a shown in previous figures, such as the C-shaped body including a pair of arms 113b each having an inlet 121b, 123b formed therein, the allograft spacer 110b need not be the same.

[0068] FIGS. 9A-9D illustrate different views of a third alternative embodiment of a low profile plate attached to a spacer according to some embodiments. In the present embodiment, the plating system 205 includes a plate 250 having lateral arms or extensions 270 that extend around an exterior surface of a spacer 210. The lateral extensions 270 extend wider than the lateral extensions 70 in the first embodiment, and do not necessarily have to interlock with the spacer 210. While in some embodiments, the plate 250 can be attached to the spacer 210 after inserting the spacer 210 into a desired location in the body, in other embodiments, the plate 250 can be pre-assembled with the spacer 210 prior to inserting the plating system 205 into the desired location.

[0069] Like the spacer 10 in FIG. 1A, the spacer 210 is configured to have an upper surface 212, a lower surface 214, and a leading end 222. In some embodiments, the upper surface 212 and/or lower surface 214 includes texturing 216, such as teeth, ribs, ripples, etc. to assist in providing frictional contact with adjacent vertebral bodies. In some embodiments, the leading end 222 of the spacer 210 can be slightly tapered, as shown in FIG. 9D. With the taper, the leading end 222 can serve as a distraction surface that helps the spacer 210 to be inserted into an intervertebral space. As shown in FIG. 9B, the leading end 222 can be slightly concave, though in other embodiments, the leading end 122 can be straight or convex. Unlike previously illustrated spacers, the spacer 210 can have a graft hole 220 that is completely enclosed. As shown in FIG. 9B, the graft hole 220 can surrounded by four walls. In addition, the spacer 210 can include four outer walls: two straight walls, a convex wall and a concave wall.

[0070] In some embodiments, the graft opening 220 (shown in FIG. 9B) has a different shape from the openings of prior embodiments, as the graft opening 220 is enclosed. While the graft opening 220 is rectangular with rounded edges, in other embodiments, the graft opening 220 can have a different shape. For example, in some embodiments, the graft opening 220 can have curved walls, instead of straight walls, or can have tapered walls, instead of straight walls.

[0071] Like spacer 10, the spacer 210 can be formed of a variety of materials. In some embodiments, the spacer 210 comprises allograft bone, while in other embodiments, the spacer 210 comprises PEEK.

[0072] The plate 250 is configured to have a pair of lateral extensions 270 that receive the spacer 220. As shown in FIG. 9A, in some embodiments, the lateral extensions 270 include one or more windows 272 for improving radiolucency of the plating system. In some embodiments, the plate 250 is assembled axially to the spacer 210.

[0073] In addition to capturing the spacer 210, the plate 250 is also configured to attach into one or more vertebral bodies via one or more bone screws 88, 89. As shown in FIG. 9A, the plate 250 includes a first screw hole 252 and a second screw hole 254 for receiving bone screws 88, 89 therein. In some embodiments, screw hole 252 is angled upwardly such that an inserted bone screw 88 passes upward into an upper vertebral body, while screw hole 254 is angled downwardly such that an inserted bone screw 89 passes downward into a lower vertebral body. While the illustrated embodiment illustrates a pair of screw holes for receiving a pair of bone screws, it is possible to have one, three, four, five or more screw holes for receiving a different number of bone screws.

[0074] Over time, it is possible for bone screws to back-out. The plate 250 thus has a blocking or set screw 256 (shown in FIG. 9C) that assists in preventing back-out of inserted bone screws. As shown in FIG. 9C, the set screw 256 can be in an initial position that allows first and second bone screws to pass through holes 252, 254. Once the bone screws have been inserted through the holes 252, 254, the set screw 256 can be rotated (e.g., 90 degrees), to thereby block the bone screws and prevent back out of the bone screws. In some embodiments, the set screw 256 abuts a side of the head of the bone screws to prevent back-out of the bone screws, while in other embodiments, the set screw 256 rests over a top of the head of the bone screws to prevent back-out of the bone screws. In some embodiments, the set screw 256 comes pre-fixed with the plate 250. As shown in FIG. 9C, a single set screw 256 can be used to conveniently block a pair of bone screws. In other embodiments, each bone screw can be assigned its own set screw, which can operate independently of one another, to prevent back-out of the bone screw.

[0075] FIGS. 10A-10D illustrate different views of the low profile plate shown in FIGS. 9A-9D. From these views, one can see the lateral extensions 270 that extend from the body of the plate 250. From these views, one can also see the windows 272 (FIG. 10A) that extend along a substantial length of the lateral extensions 270. In some embodiments, each window 272 has a length greater than half the length of each lateral extension 270, thereby advantageously increasing the radiolucency of the plating system. In some embodiments, the plate 250 is assembled axially to the spacer 210.

[0076] In some embodiments, the low profile plate 250 can also include indented gripping sections 273 (shown in FIGS. 10A and 10B). These indented gripping sections 273 advantageously provide a gripping surface for an insertion instrument, thereby facilitating easy delivery of the plate to a spacer body during surgery.

[0077] FIGS. 11A-11D illustrate different views of a fourth alternative embodiment of a low profile plate attached to a spacer according to some embodiments. Like the previous embodiment, the plating system 305 includes a plate 350 having lateral arms or extensions 370 that extend around an exterior surface of a spacer 310. The lateral extensions 370 extend wider than the lateral extensions 70 in the first embodiment, and do not necessarily have to interlock with the spacer 310. While in some embodiments, the plate 350 can be attached to the spacer 310 after inserting the spacer 310 into a desired location in the body, in other embodiments, the plate 350 can be pre-assembled with the spacer 310 prior to inserting the plating system 305 into the desired location.

[0078] Like the spacer 10 in FIG. 1A, the spacer 310 is configured to have an upper surface 312, a lower surface 314, and a leading end 322. In some embodiments, the upper surface 312 and/or lower surface 314 includes texturing 316, such as teeth, ribs, ripples, etc. to assist in providing frictional contact with adjacent vertebral bodies. In some embodiments, the leading end 322 of the spacer 310 can be slightly tapered, as shown in FIG. 11D. With the taper, the leading end 322 can serve as a distraction surface that helps the spacer 310 to be inserted into an intervertebral space. As shown in FIG. 11B, the leading end 322 can be slightly concave, though in other embodiments, the leading end 322 can be straight or convex. In some embodiments, the spacer 310 can have a graft hole 320 that is completely enclosed. As shown in FIG. 11B, the graft hole 320 can surrounded by four walls. In addition, the spacer 320 can be comprised of four outer walls: two straight, one concave and one convex.

[0079] In some embodiments, the graft opening 320 (shown in FIG. 11B) of the spacer 310 is enclosed. While the graft opening 320 is rectangular with rounded edges, in other embodiments, the graft opening 320 can have a different shape. For example, in some embodiments, the graft opening 320 can have curved walls, instead of straight walls, or can have tapered walls, instead of straight walls.

[0080] Like spacer 10, the spacer 310 can be formed of a variety of materials. In some embodiments, the spacer 210 comprises allograft bone, while in other embodiments, the spacer 310 comprises PEEK.

[0081] The plate 350 is configured to have a pair of lateral extensions 370 that receive the spacer 320. As shown in FIG. 11A, in some embodiments, the lateral extensions 370 include one or more windows 372 for improving radiolucency of the plating system. In some embodiments, the plate 350 is assembled axially to the spacer 310.

[0082] In addition to capturing the spacer 310, the plate 350 is also configured to attach into one or more vertebral bodies via one or more bone screws 88, 89. As shown in FIG. 9A, the plate 350 includes a first screw hole 351, a second screw hole 352 and a third screw hole 354 for receiving bone screws 87, 88, 89 therein. In some embodiments, screw holes 352 and 354 are angled upwardly such that inserted bone screws 87, 88 pass upward into an upper vertebral body, while screw hole 351 is angled downwardly such that inserted bone screw 89 passes downward into a lower vertebral body. While the illustrated embodiment illustrates three screw holes for receiving three bone screws, it is possible to have one, two, four, five or more screw holes for receiving a different number of bone screws.

[0083] Over time, it is possible for bone screws to back-out. The plate 350 thus has blocking or set screws 356, 357, 358 (shown in FIG. 12C), each of which corresponds to one of screw holes 351, 352, 354. As shown in FIG. 12C, the set screws 356, 357, 358 can be in an initial position that allows first, second and third bone screws to pass through holes 351, 352, 354. Once the bone screws have been inserted through the holes 351, 352, 354, the set screws 356, 357, 358 can be rotated (e.g., 90 degrees), to thereby block the bone screws and prevent back out of the bone screws. In some embodiments, the set screws 356, 357, 358 abut a side of the head of the bone screws to prevent back-out of the bone screws, while in other embodiments, the set screws 356, 357, 358 rest over a top of the head of the bone screws to prevent back-out of the bone screws. In some embodiments, the set screws 356, 357, 358 come pre-fixed with the plate 350. As shown in FIG. 12C, a single set screw 356, 357, 358 can be used to conveniently block a single bone screws. In other embodiments, each set screw can be designed to block more than one set screw to prevent back-out of the bone screw.

[0084] FIGS. 12A-12D illustrate different views of the low profile plate shown in FIGS. 11A-11D. From these views, one can see the lateral extensions 370 that extend from the body of the plate 350. From these views, one can also see the windows 372 (FIG. 12A) that extend along a substantial length of the lateral extensions 370. In some embodiments, each window 372 has a length greater than half the length of each lateral extension 370, thereby advantageously increasing the radiolucency of the plating system. In some embodiments, the plate 350 is assembled axially to the spacer 310.

[0085] The plating systems describe include a plate that is independent from a spacer. The plate is low-profile and can be used with any type of spacer, such as allograft or PEEK.

[0086] FIGS. 13A-13D illustrate different views of a multi-piece allograft spacer to be used with the low profile plates discussed above according to some embodiments. The multi-piece allograft spacer 410 can be formed of an upper member 436 and a lower member 438 that are connected together via one or more pins 475. The upper member 436 and the lower member 438 each include cut-out portions that help form a graft opening 420 in the spacer 410.

[0087] The upper member 436 can include an upper surface having bone engagement surfaces (e.g., ridges, teeth, ribs) and a lower interfacing surface 446. The lower member 438 can include a lower surface having bone engagement surfaces (e.g., ridges, teeth, ribs) and an upper interfacing surface 448. In some embodiments, the upper member 436 can include one or more holes 462, while the lower member 438 can include one or more holes 464 which align with the one or more holes 462 of the upper member. The aligned holes are configured to receive one or more pins 475 to keep the upper and lower members of the allograft spacer together. In some embodiments, the pins 475 are also formed of bone material, such as allograft.

[0088] As shown best in FIG. 13C, the lower interfacing surface 446 of the upper member 436 is directly engaged with the upper interfacing surface 448 of the lower member 438. While the lower interfacing surface 446 and the upper interfacing surface 448 can be flat-on-flat, as both surfaces are planar, in some embodiments (as shown in FIG. 13C), the interface between the two surfaces is at an angle relative to the holes for receiving the pins 475. In other words, the pins 475 are received at an angle to the interface between the upper member 436 and the lower member 438. In addition, as shown in FIG. 13C, holes 462 and 464 need not go through the entirety of their respective members. For example, as shown in FIG. 13C, while hole 462 goes entirely through the upper and lower surface of the upper member 436, hole 464 goes only through the upper surface of the lower member 438, and does not go through to the lower surface. Accordingly, in some embodiments, aligned holes 462 and 464 create a “blind” pin-hole, whereby the hole does not go through the uppermost and lowermost surfaces of the spacer 410. Advantageously, in some embodiments, the use of such blind holes for receiving pins helps to maintain the pins within the spacer body.

[0089] FIGS. 14A-14D illustrate different views of an alternative multi-piece allograft spacer to be used with the lower profile plates discussed above according to some embodiments. The multi-piece allograft spacer 510 can be formed of a left member 536 and a right member 538 that are connected together in series or side-by-side (e.g., laterally) via one or more pins 575. The left member 536 and the right member 538 each include cut-out portions that help form a graft opening 520 in the spacer 510.

[0090] The left member 536 can include upper and lower surfaces having bone engagement surfaces (e.g., ridges, teeth, ribs). In addition, the left member 536 further includes a right interfacing surface 546. The right member 538 can also include upper and lower surfaces having bone engagement surfaces (e.g., ridges, teeth, ribs). In addition, the right member 538 further includes a left interfacing surface 548. In some embodiments, the left member 536 can include one or more holes 562, while the right member 538 can include one or more holes 564 which align with the one or more holes 562 of the left member. The aligned holes are configured to receive one or more pins 575 to keep the left and right members of the allograft spacer together.

[0091] As shown best in FIG. 14A, the right interfacing surface 546 of the left member 536 is directly engaged with the left interfacing surface 548 of the right member 538. While the right interfacing surface 546 and the left interfacing surface 548 can be flat-on-flat, as both surfaces are planar, in some embodiments (as shown in FIG. 14A), the interface between the two surfaces is at an angle relative to the holes for receiving the pins 575. In other words, the pins 575 are received at an angle to the interface between the left member 536 and the right member 538. In addition, as shown in FIG. 14B, holes 562 and 564 need not go through the entirety of their respective members. In other words, one or more of the holes (e.g., holes 562, 564 or combined) can be blind holes, whereby the holes do not go through the left and right surfaces of the lateral implants.

[0092] By having multi-piece allograft spacers that are either stacked or aligned side-by-side, it is possible to have spacers of increased height and width. While the embodiments herein show two piece spacers, one skilled in the art will appreciate that three or more members can be combined to form multi-piece allograft spacers for use with any of the plate members described above.

[0093] FIGS. 15A-15D illustrate different views of an alternative low profile plate attached to a spacer according to some embodiments. The plating system 605 comprises a plate 650 attached or mounted to a spacer 610.

[0094] The system 605 includes a number of similar features to prior embodiments. The spacer 610 includes a body having an upper surface 612 and a lower surface 614 with texturing (e.g., ribs, grooves, teeth, protrusions) and sidewalls including one or more notches 617 for receiving plate extensions. The body of the spacer 610 can be U-shaped or C-shaped, such that a central portion includes a graft opening 620 for receiving graft material therein. The plate 650 includes a body having a first screw hole 652 for receiving a first screw member therethrough, a second screw hole 654 for receiving a second screw member therethrough, and a recess for receiving a blocking fastener or set screw 656. In addition, a pair of extension arms or members 670 extend from the plate body and are received in each of the notches 617 formed in the spacer 10. Each of the extension members 617 includes a window 672 for receiving a hump portion or region of the spacer to further secure the spacer 610 with the plate 650. In addition, the plate member 650 can include one or more stabilizers or knife-like edges 663 that can help secure the plate member 650 to a vertebral body. While the stabilizers 663 are shown as sharp and pointed, in other embodiments, the stabilizers 663 are more blunt and in some cases, even slightly rounded.

[0095] The plating system 605 in FIGS. 15A and 15D is unique in that the first upper screw hole 652 has been raised such that a central axis of the first upper screw hole 652 is positioned higher than the upper surface 612 of the spacer 610. In addition, the second lower screw hole 654 has been lowered such that a central axis of the second lower screw hole 654 is positioned below the lower surface 614 of the spacer 610. As shown in FIG. 15B, each of the holes 652, 654 has an adjacent brow member that extends from the plate body. First screw hole 652 is adjacent upper brow member 662, while second screw hole 654 is adjacent lower brow member 664. Upper brow member 662 has been raised to accommodate the raised upper screw hole 652, while lower brow member 664 has been lowered to accommodate the lowered lower screw hole 654. Advantageously, by raising the upper screw hole 652 and lowering the lower screw hole 654, this reduces the likelihood of any viewing obstruction that may occur from the spacer 610. Moreover, even though the upper brow member 662 is raised and the lower brow member 664 is lowered, advantageously, the plating system 605 still maintains a low profile such that most if not all of the plate system remains in a disc space. In other embodiments, it may be desired for a part of the upper brow member 662, a part of the lower brow member 664 or both to contact a vertebral face (e.g., an anterior face), thereby providing stability to the plating system 605.

[0096] FIGS. 16A-16D illustrate different views of a plate member 650 used in the plating system 605. From these views, one can clearly see how the upper brow member 662 and first upper hole member 652 have been raised, while the lower brow member 664 and second lower hole member 664 have been lowered, relative to other designs. In some embodiments, the entire central axis of first upper hole member 652 (e.g., from a front of the plate member 650 to a back of the plate member 650) is continuously above the upper surface of the spacer, thereby advantageously providing a less unobstructed view of the first upper hole member 652. Likewise, in some embodiments, the entire central axis of the second lower hole member 654 (e.g., from a front of the plate member 650 to a back of the plate member 650) is continuously below the lower surface of the spacer, thereby advantageously providing a less unobstructed view of the second lower hole member 654.

[0097] FIGS. 17A-17C illustrate different views of a spacer 610 used in the plating system 605. From these views, one can clearly see features of the spacer 610 includes its upper surface 612, lower surface 614, sidewalls with notches 617 and graft opening 620. In addition, with the plate member removed from the views, one can also see an upper chamfer 618a and a lower chamfer 618b that are cut into the spacer 610. These chamfers 618a, 618b advantageously provide clearance for bone screws that are inserted through the plating system 605. One skilled in the art will appreciate that the spacer can be made of many different materials. In some embodiments, the spacer will be made out of bone (e.g., allograft), while in other embodiments, the spacer will be made of PEEK. Advantageously, the plating system 605 is removably attached to the spacer 610 such that a surgeon can choose to include a spacer of a certain material as so desired during a surgical procedure.

[0098] FIGS. 18A-18D illustrate different views of yet another plate system involving a plate member and a spacer having a unique multi-piece composition in accordance with some embodiments. The plate system 705 includes similar elements as found in prior embodiments, including a plate member 750 having a first upwardly oriented screw hole 752 for receiving a first screw, a second downwardly oriented screw hole 754 for receiving a second screw, and a blocking member or screw 756, as well as a spacer 710 (e.g., allograft or PEEK) having an upper surface 712, a lower surface 714, a graft opening 720, and notches 717 for receiving arms or extensions 770 of the plate member 750. The plate member 750 also includes one or more windows 772 in its extensions 770 for receiving a raised or bump out portion of the spacer 705, thereby helping to retain the spacer 705 within the plate member 750. In addition, the plate member 750 includes stabilizers 763 in the form of knife-like edges that help to grip into a vertebral body.

[0099] In addition to these features, the spacer 710 has a unique multi-piece composition. As shown in FIGS. 18A and 18D, in some embodiments, the spacer 710 has a body formed of two adjacent members—a first member 711 and a second member 713. The first member 711 and the second member 713 can be held together via one or more pin members, although in other embodiments, the first member 711 and second member 713 can be held via adhesive, mateable connections, etc. As shown in FIG. 18D, second member 713 can include an upper overhang region 717 that hangs over a part of the first member 711. Similarly, first member 711 can include a lower overhang region 711 that hangs below a part of the second member 713. Advantageously, these overhang regions 711 serve as guides to identify the location of the interface 715 between the first member 711 and the second member 713. During manufacturing, the overhang regions 711 make it easy to inspect the interface to 715 to ensure that the two members 711, 713 are properly secured together. While the illustrated embodiment shows a spacer 710 having two separate overhanging regions, in other embodiments, the spacer 710 can have one single overhanging region. As before, the spacer 710 can be made of many different types of materials, including bone (e.g., allograft) and PEEK), and a surgeon can advantageously decide what type of spacer should accompany the plate before or during surgery.

[0100] FIG. 19 shows a plating system 805 having a plate member 850 having extensions 870 and a spacer 810 similar to that found in FIGS. 18A-18D; however, the spacer 810 is designed to accommodate lordosis. In other words, while the upper surface 712 and lower surface 714 of the spacer 710 can be substantially parallel (as shown in FIG. 18C), the upper surface 812 and lower surface 814 of the spacer 810 can have some degree of angulation or lordosis. In some embodiments, relative to a mid-line of the spacer 810, the upper surface 812 and/or lower surface 814 can have a degree of angulation of 2, 3, 5, 7, 12 degrees or more. Advantageously, the lordotic spacer 810 (which is accompanied with the plate member 850) helps to accommodate different anatomies.

[0101] FIGS. 20A-20D show yet another alternative plating system having a plate member attached to multiple spacers in accordance with embodiments of the present application. The unique plating system 905 comprises a plate member 950 having a pair of inner arms or extensions 975 and a pair of outer arms or extensions 970 for receiving one or more spacers 910 therein. In some embodiments, both the inner and outer extensions 975, 970 include protruding portions designed to be received in notches in the one or more spacers.

[0102] As shown in FIG. 20A, the plating system 905 includes a first spacer 910a that is retained between a shorter outer extension 970 and a longer inner extension 975 of the plate member 950. The shorter outer extension 970 of the plate is configured to be received in notch 917 of the spacer 910a, while the longer inner extension 975 of the plate is configured to be received in notch of the spacer 910a. In addition, advantageously, the shorter outer extension 970 includes a window 972 and the longer inner extension 975 includes a window 974. Each of the windows 972, 974 is configured to receive a bump out portion of the spacer 910, thereby helping to retain the spacer 910 to the plate member 905. In addition, the windows 972, 974 help to provide a means to visualize fusion (e.g., in a lateral image) that is occurring once the spacer is implanted within a disc space. Similarly, the plating system 905 includes a second spacer 910b that is retained between a shorter outer extension 970 and a longer inner extension 975 on an opposite side of the plate member 950. While in the present embodiment, each of the longer inner extensions 975 is separated from the other without any connecting member, in other embodiments, a connection bar or bridge (such as shown in FIGS. 21A and 21B) can extend between the two inner extensions 975. Advantageously, when the plating system 905 is placed in a disc space, graft material can be packed between the two inner extensions 975 to promote fusion within the disc space.

[0103] Advantageously, in accordance with some embodiments, the plating system 905 is designed to hold at least two spacers 910a, 910b. In some embodiments, the spacers 910a, 910b are substantially rectangular pieces. In some embodiments, the spacers 910a, 910b can have substantially rounded edges. In some embodiments, the spacers 910a, 910b can include one or more chamfers 918 for providing clearance for one or more screws that are inserted through the plate member 905. For example, spacer 910a can include a chamfer that provides clearance for a screw that passes through plate opening 954, while spacer 910b can include a chamfer that provides clearance for a screw that passes through plate opening 952. Advantageously, the use of two spacers 910a, 910b—one on each side of the plate system 905—helps to stabilize the plate system within the disc space. Moreover, having multiple individual spacers 910a, 910b that are smaller in size can ease manufacturing issues, as the spacers can be formed of relatively small pieces of bone, which can be easier to find than larger pieces of bone. In other words, bone that is removed from a body can improve the yield of production, as it will be easier to create the spacer members. While the spacers 910a, 910b are illustrated as being single-bodied members in the present embodiments, in other embodiments, the spacers can be formed of multiple pieces (e.g., pinned together).

[0104] FIGS. 21A and 21B illustrate different views of another alternative low profile plate attached to multiple spacers according to some embodiments. The plate system 1005 comprises a plate member 1050 attached to a pair of spacers 1010a and 1010b. Like the embodiment in FIG. 20A, the plate member 1050 of the present embodiment includes a pair of outer arms or extensions 1070a, 1070b and a pair of inner arms or extensions 1075a, 1075b. Plate extensions 1070a and 1075a are configured to retain spacer 1010a, while plate extensions 1070b and 1075b are configured to retain spacer 1010b. As shown in FIGS. 21A and 21B, the inner extensions 1075a and 1075b includes a connection or bridge member 1088 that extends between them. Advantageously, the bridge member 1088 helps provide added stability to the plate system 1005, and also helps provide a barrier to retain graft material within the plate system 1005. As shown in FIG. 21A, in some embodiments, the inner extensions 1075a and 1075b are parallel to one another.

[0105] As shown in FIG. 21B, outer plate extensions 1070a and 1070b include at least one window 1072 formed therein. Similarly, inner plate extensions 1075a and 1075b include at least one window formed therein. As shown in FIG. 21B, inner plate extensions each include two windows—1074 and 1075—that are formed adjacent to one another. Inner plate extension 1075a includes windows 1074a and 1075a, while inner plate extension 1075b includes windows 1074b and 1075b. In some embodiments, the windows 1072, 1074, 1075 can advantageously be designed to hold a bump out portion of the spacers and/or provide increased visualization to a surgeon during or after a fusion procedure. While in some embodiments, each of the windows 1072, 1074, and 1075 perform the same duties and functions, in other embodiments, the windows can perform different functions. For example, while inner window 1074 can be used to both retain the spacer and aid in fusion visualization, inner window 1075 can be used simply for fusion visualization.

[0106] FIG. 22 illustrates another alternative low profile plate attached to multiple spacers according to some embodiments. The plate system 1105 comprises a plate member 1150 attached to a pair of spacers 1110a and 1110b. Like the embodiment in FIG. 21A, the plate member 1150 of the present embodiment includes a pair of outer arms or extensions 1170a, 1170b and a pair of inner arms or extensions 1175a, 1175b. Plate extensions 1170a and 1175a are configured to retain spacer 1110a, while plate extensions 1170b and 1175b are configured to retain spacer 1110b. As shown in FIGS. 21A and 21B, the inner extensions 1175a and 1175b includes a connection or bridge member 1188 that extends between them. Advantageously, the bridge member 1188 helps provide added stability to the plate system 1105, and also helps provide a barrier to retain graft material within the plate system 1105. In contrast to the inner extensions 1075a, 1075b in FIG. 21A, the inner extensions 1175a, 1175b are non-parallel and angulated relative to one another. Furthermore, due to the shape of the plate member 1150, the shapes of the individual spacers 1110a and 1110b differ in that they have a prominent angled surface adjacent to the inner extensions 1175a, 1175b.

[0107] FIG. 23 illustrates another alternative low profile plate attached to multiple spacers according to some embodiments. The plate system 1205 comprises a plate member 1250 attached to a pair of spacers 1210a and 1210b. Like the embodiment in FIG. 22, the plate member 1250 of the present embodiment includes a pair of outer arms or extensions 1270a, 1270b and a pair of inner arms or extensions 1275a, 1275b. Plate extensions 1270a and 1275a are configured to retain spacer 1210a, while plate extensions 1270b and 1275b are configured to retain spacer 1210b. As shown in FIG. 23, the inner extensions 1275a and 1275b includes a connection or bridge member 1288 that extends between them. Advantageously, the bridge member 1288 helps provide added stability to the plate system 1205, and also helps provide a barrier to retain graft material within the plate system 1205. In contrast to the bridge member 1188 in FIG. 22, the bridge member 1288 is elongated and extends to a distal end of the spacers 1210a, 1210b, thereby creating an even larger space for receiving graft material in the middle of the plate system 1205.

[0108] FIGS. 24A-24C illustrate another alternative low profile plate attached to multiple spacers according to some embodiments. The plate system 1305 comprises a plate member 1350 attached to a multi-piece spacer 1310 formed of three members 1310a, 1310b, 1310c. Like the embodiment in FIG. 23, the plate member 1350 of the present embodiment includes a pair of outer arms or extensions 1370a, 1370b and a pair of inner arms or extensions 1375a, 1375b connected by a bridge member 1388. The inner extensions 1375a, 1375b and bridge member 1388 are configured to be enclosed by the body of the spacer 1310. Advantageously, the bridge member 1388 helps provide added stability to the plate system 1305, and also helps provide a barrier to retain graft material within the plate system 1305.

[0109] In some embodiments, the spacer 1310 is formed of three different members 1310a, 1310b, 1310c. The members 1310a and 1310b can be outer members which bound the inner member 1310c. As shown in FIG. 24C, the members 1310a and 1310b can be substantially similar, and can include upper and lower surfaces with surface protrusions to enable better gripping of bone. Inner member 1310c can be different from the other members and can include a relatively smooth surface without surface protrusions. In addition, the inner member 1310c can be of a different height than the other members. In some embodiments, the three members 1310a, 1310b, 1310c are pinned together, while in other embodiments, they can be joined together via an adhesive or mateable connection. Advantageously, the addition of the inner member 1310c provides further support to the overall structure of the plate system 1305.

[0110] FIGS. 25A and 25B illustrate another alternative low profile plate attached to a multi-piece spacer having a metal insert according to some embodiments. The plate system 1405 comprises a plate member 1450 attached to a multi-piece spacer 1410 formed of two similar components 1410a, 1410b and a metal insert 1439. The plate member 1450 can include a first screw opening, a second screw opening and a rotatable locking mechanism 1456 to prevent back out of screws that are inserted through the openings. In some embodiments, the plate member 1450 of the present embodiment is mounted to the front of the spacer. In other embodiments, the plate member 1450 includes a pair of outer arms or extensions and/or a pair of inner arms or extensions (not shown) to help retain the spacer 1410 within the plate member 1450.

[0111] In some embodiments, the spacer 1410 is formed of two members 1410a and 1410b separated by a metal insert 1439. These members partially enclose a graft opening 1420. The two members 1410a and 1410b can be formed of a material different from the metal insert 1439, such as PEEK. Advantageously, the metal insert 1439 is designed to provide additional strength to the spacer 1410. In some embodiments, the metal insert 1439 is formed of titanium. As shown in the exploded view in FIG. 25B, the spacer 1410 be attached to the plate member 1450 via vertical fastening members 1429a, 1429b. One skilled in the art will appreciate that the spacer 1410 can be used with any of the other plate members discussed above.

[0112] FIGS. 26A-26D illustrate another alternative plate having raised and lowered screw openings in attachment with a spacer according to some embodiments. The plate 1550 and spacer 1510 have many similar features as in prior embodiments; however, the upper screw hole 1552 in the plate 1550 has been raised, while the lower screw hole 1554 in the plate 1550 has been lowered. The upper screw hole 1552 has been raised such that a center axis of the upper screw hole 1552 is positioned entirely above an upper surface 1512 of the spacer 1510. The lower screw hole 1554 has been lowered such that a center axis of the lower screw hole 1554 is positioned entirely below a lower surface 1514 of the spacer 1510. Advantageously, by raising the upper screw hole 1552 such that a center axis extends completely above the upper surface 1512 of the spacer 1510, this provides a plate member 1550 having increased visibility on its upper end and also provides an upper plate portion that can be uniquely positioned relative to a disc space, as shown in FIG. 28. Likewise, by lowering the lower screw hole 1554 such that a center axis extends completely below the lower surface 1514 of the spacer 1510, this provides a plate member 1550 having increased visibility on its lower end and also provides a lower plate portion that can be uniquely positioned relative to a disc space, as also shown in FIG. 28.

[0113] In some embodiments, the plate 1550 and the spacer 1510 have many similar features as in prior embodiments. For example, the spacer 1510 is configured to have a body having an upper surface 1512 in contact with an upper vertebral body and a lower surface 1514 in contact with a lower vertebral body. The spacer body includes notches for receiving portions of the plate 1550 therein. In some embodiments, the spacer 1510 is formed of a natural material, such as allograft bone.

[0114] The plate 1550 includes the upper screw hole 1552 and the lower screw hole 1554, and a pair of arms or extensions that are designed to be received within the spacer 1510. As noted above; the upper screw hole 1552 has been raised such that a center axis that extends through the upper screw hole 1552 is positioned higher than an upper surface of the spacer 1510. In some embodiments, only a portion of the center axis through the upper screw hole 1552 is positioned higher than an upper surface of the spacer 1510, while in other embodiments, the entire center axis through the upper screw hole 1552 is positioned higher than an upper surface of the spacer 1510. Likewise, the lower screw hole 1554 has been lowered such that a center axis that extends through the lower screw hole 1554 is positioned lower than a lower surface of the spacer 1510. In some embodiments, only a portion of the center axis that passes through the lower screw hole 1554 is positioned lower than a lower surface of the spacer 1510, while in other embodiments, the entire center axis through the lower screw hole 1552 is positioned lower than a lower surface of the spacer 1510.

[0115] In some embodiments, the plate 1550 includes an upper extension, eyelid or rim 1571 through which the upper screw hole 1552 can pass through. In some embodiments, the upper rim 1571 has an anterior or front face 1553 and a posterior or back face 1555 (identified in FIG. 26C). In some embodiments, both the front face 1553 and the rear face 1555 of the upper rim 1571 are straight and vertical and not angled relative to height of vertical axis of the spacer. In other embodiments, either the front face 1553 or the rear face 1555 can be straight, while the other face can be angled (e.g., in an anterior direction). In yet other embodiments, both the front face 1553 and the rear face 1555 of the upper rim 1571 can be angled. Advantageously, in some embodiments, the upper screw hole 1552 extends through the upper rim 1571 at an angle such that a screw that is inserted through the upper screw hole 1552 will be inserted at or near a corner edge of an upper vertebral body (as shown in FIG. 28). By being positioned at or near a corner edge of the upper vertebral body, it is not necessary for the screw to be positioned through an anterior face or aspect of the upper vertebral body, thereby maintaining a low profile implant. In some embodiments, the majority or entirety of the upper rim 1571 including the upper screw hole 1552 can be configured such that the upper portion of the plate rests at or near a corner edge of the upper vertebral body, thereby maintaining a low profile implant.

[0116] In some embodiments, the plate 1550 includes a lower extension, eyelid or rim 1573 through which the lower screw hole 1554 can pass through. In some embodiments, the lower rim 1573 has an anterior or front face 1553 and a posterior or back face 1555 (identified in FIG. 29A). In some embodiments, both the front face 1553 and the rear face 1555 of the lower rim 1573 are straight and vertical and not angled relative to height of vertical axis of the spacer. In other embodiments, either the front face 1553 or the rear face 1555 can be straight, while the other face can be angled (e.g., in an anterior direction). In yet other embodiments, both the front face 1553 and the rear face 1555 of the lower rim 1573 can be angled. Advantageously, in some embodiments, the lower screw hole 1554 extends through the lower rim 1573 at an angle such that a screw that is inserted through the lower screw hole 1554 will be inserted at or near a corner edge of a lower vertebral body (as shown in FIG. 28). By being positioned at or near a corner edge of the lower vertebral body, it is not necessary for the screw to be positioned through an anterior face or aspect of the upper vertebral body, thereby maintaining a low profile implant. In some embodiments, the majority or entirety of the lower rim 1573 including the lower screw hole 1554 can be configured such that the lower portion of the plate rests at or near a corner edge of the lower vertebral body, thereby maintaining a low profile implant. Advantageously, in some embodiments, at least a portion of the upper rim 1571 and/or a portion of the lower rim 1573 is maintained within the disc space between the upper vertebral body and the lower vertebral body, thereby maintaining an implant with a low profile.

[0117] FIGS. 27A-27D illustrate another alternative plate having raised and lowered screw openings in attachment with a spacer according to some embodiments. The plate 1550 and the spacer 1610 are similar to the assembly in FIGS. 26A-26D, except the spacer 1610 is formed of a different material, such as PEEK. Advantageously, the plate 1550 is capable of being assembled with either the bone spacer 1510 shown in FIGS. 26A-26D or the PEEK spacer 1610 shown in FIGS. 27A-27D prior to insertion into a disc space, thereby providing versatility to a surgeon.

[0118] FIG. 28 illustrates the plate and spacer in FIGS. 26A-26D in use within a vertebral space. From this view, one can see how the plate 1510 is designed to have an upper rim 1571 that accommodates an upper screw hole 1552 and a lower rim 1573 that accommodates a lower screw hole 1554. The upper screw hole 1552 receives an upwardly angled screw that is configured to be inserted at or near a corner of the upper vertebral body, thereby avoiding insertion through an anterior face or aspect of the upper vertebral body. The lower screw hole 1554 receives a downwardly angled screw that is configured to be inserted at or near a corner of the lower vertebral body, thereby avoiding insertion though an anterior face or aspect of the lower vertebral body.

[0119] FIGS. 29A-29C illustrate the plate in FIGS. 26A-26D without a spacer. As shown in these figures, the plate 1550 includes an upper rim 1571 that accommodates an upwardly angled screw hole 1552 and a lower rim 1573 that accommodates a downwardly angled screw hole 1554. The upper rim 1571 includes a front or anterior face 1553a and a rear or posterior face 1555a, while the lower rim 1573 includes a front or anterior face 1553b and a rear or posterior face 1555b. As shown in FIG. 29B, in some embodiments, the entire anterior face of the plate (e.g., including the upper anterior face of the upper rim 1571 and the lower anterior face of the lower rim 1573) can be straight and non-angled. In other embodiments, portions of the anterior face can be slightly angled, such as in an anterior direction. In addition, as shown in FIG. 29B, in some embodiments, portions of the posterior faces of the plate (e.g., posterior faces 1555a and 1555b) can also be straight and non-angled. In other embodiments, portions of the posterior faces can be angled (e.g., in an anterior direction), such as 5 degrees, 10 degrees, 15 degrees, or more. In some embodiments, the anterior and/or posterior faces of the rims can be angled between 5 and 15 degrees.

[0120] FIGS. 30A-30E illustrate different views of an allograft spacer 1510 that can be used with the plate in FIGS. 26A-26D. The allograft spacer 1510 includes a notch 1517 for receiving extension members of the plate therein. FIGS. 31A-31E illustrate different views of a PEEK spacer 1610 that can be used with the same plate. The PEEK spacer 1610 includes a notch 1617 for receiving extension members of the plate therein. As noted above, the surgeon can desirably choose which spacer to insert into a surgical site.

[0121] FIGS. 32A and B illustrate different views of a spacer 1710 (either allograft or PEEK) for receiving extension members of the plate. The spacer 1710 includes a pair of channels or notches 1717 for receiving an extension member from a plate. Each of the notches 1717 extends a vertical distance from an upper surface of the spacer 1710 to a lower surface of the spacer 1710.

[0122] In FIG. 32B, a single notch 1717 out of a pair of notches is visible from the sideview. Each of the notches 1710 is comprised of two sidewalls 1721, 1723 that form a channel that extend from an upper surface to a lower surface of the spacer 1710. In some embodiments, one or more of the sidewalls 1721, 1723 can be straight with no angle or curvature. However, in other embodiments, as shown in FIG. 31, one or more sidewalls 1721, 1723 can have a curved portion. In the figure, first sidewall 1721 comprises a first curved portion 1722, while second sidewall 1723 comprises a second curved portion 1724. Due to the curved portions 1723, 1724, each of the notches 1710 can form a bent, curved or tortured channel for receiving an extension member of a plate therein. The advantage of having a tortured channel for receiving an extension member (such as any of the extension members 70 in FIG. 2D, 170 in FIG. 6D, 670 in FIG. 16B, 870 in FIG. 19, 970 in FIG. 20B, etc), is that this provides a tighter fit between the respective plate member and the spacer. Should a plate-spacer system encounter any forces that might cause slippage of the plate from the spacer, the tortured channel 1717 reduces the likelihood that this will occur.

[0123] As shown in FIG. 32B, the first sidewall 1721 and the second sidewall 1723 of the notch 1717 can include a straight upper portion, a curved or bent middle portion, and a straight lower portion. While the sidewalls 1721, 1723 are shown as substantially or completely parallel to each other in the figure, in other embodiments, the sidewalls 1721, 1723 need not be aligned with one another, so long as the sidewalls form a bent or tortured path through the spacer.

[0124] One skilled in the art will appreciate that any of the plate systems described above can be used with other spinal implants. Among the other implants that can accompany the plate systems include stabilization systems and rod systems, including rod members, hook members, and bone fasteners such as pedicle screws. One skilled in the art will appreciate that any of the plate systems described above can also be used with one another, or can be used multiple times along different segments of the spine. In addition, any of the plate systems described above can be used with a variety of navigation and guidance tools, including those related to neuromonitoring and robotics. Furthermore, one of skill in the art will appreciate that the plate systems described above can be produced in a number of different ways, including in part via 3-D printing methods.

[0125] It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. Moreover, the improved plate systems and bone screw assemblies and related methods of use need not feature all of the objects, advantages, features and aspects discussed above. Thus, for example, those skilled in the art will recognize that the invention can be embodied or carried out in a manner that achieves or optimizes one advantage or a group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein. In addition, while a number of variations of the invention have been shown and described in detail, other modifications and methods of use, which are within the scope of this invention, will be readily apparent to those of skill in the art based upon this disclosure. It is contemplated that various combinations or subcombinations of these specific features and aspects of embodiments may be made and still fall within the scope of the invention. Accordingly, it should be understood that various features and aspects of the disclosed embodiments can be combined with or substituted for one another in order to form varying modes of the discussed bone screw assemblies. Thus, it is intended that the present invention cover the modifications and variations of this invention provided that they come within the scope of the appended claims or their equivalents.