Patent Description:
The present disclosure relates to orthopedic implants, and more particularly, to spinal implants that facilitate fusion of bone segments. Even more particularly, the disclosure relates to porous implantable interbody devices having an engineered porous scaffold structure for enhanced bone fusion.

The integrity of the spine and its subcomponents like the vertebral bodies and intervertebral discs, both of which are well known structural body parts that make up the spine, is a key factor to maintaining a patient's good health. These parts may become weakened, damaged or broken as a result of trauma, injury, or disease (e.g., by tumor, autoimmune disease), or as a result of wear over time, or degeneration caused by the normal aging process.

In many instances, one or more damaged structural body parts can be repaired or replaced with a prosthesis or implant. For example, specific to the spine, one known method of repair is to remove the damaged vertebra (in whole or in part) and/or the damaged disc (in whole or in part) and replace it with an implant or prosthesis. In some cases, it is necessary to stabilize a weakened or damaged spinal region by reducing or inhibiting mobility in the area to avoid further progression of the damage and/or to reduce or alleviate pain caused by the damage or injury. In other cases, it is desirable to join together the damaged vertebrae and/or induce healing of the vertebrae. Fusion of the spine is a well-known and widely practiced medical procedure to alleviate symptoms and potential problems related to spinal instability such as severe back and/or neck pain due to misaligned, damaged or otherwise diseased spines. Accordingly, an implant or prosthesis for rigid fixation of the vertebrae may be utilized to facilitate fusion between two adjacent vertebrae. The implant or prosthesis may be implanted without attachment means, or fastened in position between adjacent structural body parts (e.g., adjacent vertebral bodies).

Typically, an implant or prosthesis is secured directly to a bone structure by mechanical or biological means. One manner of spine repair involves attaching a fusion implant or prosthesis to adjacent vertebral bodies using a fixation element, such as a bone screw. Most implants and their attachment means are configured to provide an immediate, rigid fixation of the implant to the implantation site. Unfortunately, after implantation the implants tend to subside, or settle, into the surrounding environment as the patient's weight is exerted upon the implant. In some cases, this subsidence may cause the rigidly fixed attachment means to either loosen, dislodge or potentially damage one or more of the vertebral bodies.

Several known surgical techniques can be used to implant a spinal prosthesis. The suitability of any particular technique may depend upon the amount of surgical access available at the implant site. For instance, a surgeon may elect a particular entry pathway depending on the size of the patient or the condition of the patient's spine, such as where a tumor, scar tissue, great vessels, or other obstacle is present. Other times, it may be desirable to minimize intrusion into the patient's musculature and associated ligamentous tissue. In some patients who have had prior surgeries, implants or fixation elements may have already been inserted into the patient's spine, and as such, an implant introduction pathway may have to account for these prior existing conditions.

It is well recognized now that porosity, pore size, and pore size distribution all serve important roles in promoting revascularization, bone healing and bone remodeling, and are key contributing factors to successful bone fusion. Further, recent advances in manufacturing techniques now enable intricate porous structures to be easily created from metal or metal alloy. Some of these techniques include selective layer melting (SLM), E-beam or 3D printing of metal or metal alloy to create complex metal structures in a layer-by-layer deposition process. These porous metal structures can act as trabecular bone type frameworks for the implantable devices.

Thus, it is desirable to provide porous metal or metal alloy implantable spinal fusion devices that can repair and/or replace damaged bone segments in the spine while allowing better fusion for improved bone healing and bone regrowth.

Implants using a solid scaffold and porous portions allowing tissue ingrowth are known from <CIT> and <CIT>.

The objects discussed above can be reached by an implantable device according to the independent claim. Some preferred embodiments are given by the dependent claims.

The embodiments provide porous implantable interbody or spinal fusion devices formed of metal, metal alloy or polymer. These porous implantable interbody devices may be engineered to have a porous scaffold structure for enhanced bone fusion.

According to the present disclosure, an implantable device that is configured for insertion into a patient's intervertebral disc space is provided. In accordance with one exemplary embodiment, the implantable device has a body configured for lateral insertion between vertebral bodies of a spine. The body has an upper surface, a lower surface, a pair of sidewalls extending in parallel between the upper and lower surfaces, an anterior portion, and a posterior portion tapering from the upper and lower surfaces to form a curved leading edge extending between the sidewalls, the curved leading edge converging at a sharpened tip to allow concomitant distraction of soft tissue during insertion.

The body comprises a solid scaffold structure. At least one of the upper surface, lower surface or sidewalls may further have a porous structure integrated into the body, the porous structure being configured to allow bony ongrowth and bony ingrowth therethrough. The porous structure has a repeating geometric unit of cells. This porous structure may be integrated into the device such that the interface between the porous structure and the upper surface, lower surface or sidewalls is seamless and void of mechanical or chemical bonding. In addition, the device may further include a central opening between the upper and lower surfaces to receive bone graft material. In some embodiments, the outer surfaces may be roughened or textured.

The porous structure may comprise a mesh or lattice structure, and may be contained within a solid perimeter structure. The porous structure may comprise a plurality of randomized cell units. Each of the cell units may have a dodecahedron, or partial dodecahedron, geometry. The upper and lower surfaces may be non-parallel such that one of the pair of sidewalls has a greater height than the other sidewall to form a wedge-shaped body. The device may include a graft containment porous groove around the central opening.

In one embodiment, the anterior portion of the device may include one or more apertures for receiving a fixation element. The one or more apertures may be hourglass shaped. In another embodiment, the anterior portion of the device may include an aperture for receiving an insertion tool.

The device may be formed of a biocompatible metal, metal alloy, or polymer, and may be 3D printed or manufactured by SLM techniques.

According to the present disclosure, an implantable device that is configured for midline insertion into a patient's intervertebral disc space is provided. The implantable device has a generally trapezoidal body configured for midline insertion between vertebral bodies of a spine. The body has an upper surface, a lower surface, an anterior portion, a posterior portion, and a pair of sidewalls extending between the upper and lower surfaces and connecting the posterior and anterior portions. The device may include rounded or curved posterolateral corners.

At least one of the upper surface, lower surface or sidewalls further have a porous structure integrated therein, the porous structure being configured to allow bony ongrowth and bony ongrowth and bony ingrowth therethrough. This porous structure may be integrated into the device such that the interface between the porous structure and the upper surface, lower surface or sidewalls is seamless and void of mechanical or chemical bonding. In addition, the device may further include a central opening between the upper and lower surfaces to receive bone graft material. In some embodiments, the outer surfaces may be roughened or textured.

The porous structure may comprise a mesh or lattice structure, and may be contained within a solid perimeter structure. The porous structure may comprise a plurality of randomized cell units. Each of the cell units may have a dodecahedron geometry. The upper and lower surfaces may be non-parallel such that one of the pair of sidewalls has a greater height than the other sidewall to form a wedge-shaped body. The device may include a graft containment porous groove around the central opening.

The device may be formed of a biocompatible metal, metal alloy or polymer, and may be 3D printed or manufactured by SLM techniques.

In accordance with still another exemplary embodiment, the implantable device may be sized and configured for insertion into the cervical spine. The device may be configured to allow stacking of the devices at different spinal levels.

According to still another aspect of the present disclosure, an implantable device that is configured for a lateral oblique angular insertion into a contra lateral and posterior spinal space is provided. In accordance with one exemplary embodiment, the implantable device has a body with an upper surface, a lower surface, and a pair of sidewalls extending therebetween. The sidewalls may be connected by an intermediate wall segment and converge at a nose or tip. The pair of sidewalls may include one sidewall that is longer than the other sidewall, and form a shark's fin shaped body. The body may further include a central opening extending through the upper and lower surfaces. The body may be configured for insertion along a trajectory represented by an axis that is oblique relative to a midline of a vertebral body of a patient's spine.

The implantable device facilitates fusion and may be used with a graft material that can be placed within the central opening. At least one of the upper surface, lower surface or sidewalls further have a porous structure integrated therein, the porous structure being configured to allow bony ongrowth and bony ingrowth therethrough. This porous structure may be integrated into the device such that the interface between the porous structure and the upper surface, lower surface or walls is seamless and void of mechanical or chemical bonding. In addition, the outer surfaces may be roughened or textured.

In one embodiment, the intermediate wall segment may include one or more apertures for receiving a fixation element. The one or more apertures may be hourglass shaped. In another embodiment, the intermediate wall segment may include an aperture for receiving an insertion tool.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. Additional features of the disclosure will be set forth in part in the description which follows or may be learned by practice of the disclosure.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several embodiments of the disclosure and together with the description, serve to explain the principles of the disclosure.

The present disclosure provides various porous implantable interbody or spinal fusion devices, which may be formed of metal, metal alloy or polymer,. These porous implantable interbody devices may be engineered to have a porous network or scaffold structure for repairing and/or replacing damaged bone segments in the spine while allowing better fusion for improved bone healing and bone regrowth.

Porosity, pore size, and pore size distribution all play important roles in promoting revascularization, bone healing and bone remodeling, and are key contributing factors to successful bone fusion. With recent advances in manufacturing techniques, it is now possible to create intricate, interlinked or interconnected porous structures such as the various porous lattice structures shown in <FIG>. Some of these manufacturing techniques include selective layer melting (SLM) or 3D printing of metal, metal alloy or polymer. Both techniques employ a layer-by-layer deposition approach to building these types of complex and interlinked, interconnected porous metal structures. As can be seen in the models of <FIG>, these porous metal structures <NUM> can have varying sized pores <NUM> interspersed throughout as well as solid portions <NUM>, while still being interlinked so as to form a complex open channel configuration extending all the way through.

The manufacturing technique also enables the device to have repetitive, specifically shaped geometric units built to form an interconnected web of repeating geometric units of cells. In one embodiment, the cell unit is a dodecahedron, or partial dodecahedron, for example. The cell unit may be based on a lightweight cell structure that is suitable for natural bone ongrowth and/or bone ingrowth. Thus, the device may include a porous lattice structure that comprises a plurality of dodecahedron shaped cell units. The resultant devices have metal bodies with randomized, organic cell geometry or pore structure geometry and pore size that mimics the structure of natural bone. Accordingly, smaller cell units may nest within larger cell units. These cells may have smooth or roughened, textured surfaces. In this manner, these engineered devices mimic trabecular bone and serve as improved metal frameworks to facilitate better bony fusion for improved bone healing and bone regrowth, as will be described in greater detail below.

Turning now to the drawings, <FIG> illustrate various porous implantable interbody, or spinal fusion, devices of the present disclosure. These devices may be configured for a specific type of surgical insertion approach into the spine, or for use at a specific spinal segment, while having a common platform of the complex, interconnected porous network described herein. Each device may serve as an engineered porous scaffold for bone fusion. These devices may be formed of a metal, metal alloy or polymer, as well as other, different materials, and can therefore be considered a hybrid titanium alloy support structure with a scaffold designed for ease of use and low stiffness, to minimize risk of stress shielding and promote mechanical stimulus of graft material, in line with Wolff's law.

The devices may be configured to have optimized endplate contact surface area for enhanced subsidence resistance to mitigate risk of subsidence, which has been a historic issue with bulky metallic implants. In one embodiment, the device may be between <NUM>% to <NUM>% porous. The engineered porous scaffold platform may include scaffold based features like variable or random fine pore geometry (such as, for example, pores in the range of about <NUM> to about <NUM>, with nominal pores size of about <NUM>) that is intended to optimize fusion / healing with rapid new bone formation. The pores are interspersed throughout solid portions of the scaffold, which solid portions provide a smooth surface or appearance, and create a lattice-like, or mesh-like, structure of random porous and non-porous (solid) surfaces, as shown in <FIG>. Thus, the scaffolds on which the implantable interbody devices of the present disclosure are based have an organic appearance (i.e., mimic natural trabecular bone structure). The devices can be provided in various sizes and configurations, as stated above, for specific clinical applications while providing superior total bone graft volume. For purposes of illustration, certain specifically configured implantable interbody devices of the present disclosure are now described in greater detail below.

As shown in <FIG> and <FIG>, exemplary embodiments of implantable spinal fusion or interbody devices <NUM>, <NUM>' configured for lateral insertion into the spine can be provided in accordance with the principles of the present disclosure.

<FIG> illustrate an exemplary embodiment of an implantable interbody device <NUM> that may be implanted in the intervertebral space between vertebral bodies and secured to the vertebral bodies with fixation screws. The implantable interbody device <NUM> may be employed in the lumbar or thoracic regions.

The implantable interbody device <NUM> may include posterior and anterior portions <NUM>, <NUM> and upper and lower surfaces profiled to correspond with the profile of any bone material to which they are to be secured. Upper and lower surfaces <NUM>, <NUM> may be flat or planar, or may be domed or convexly curved. A pair of sidewalls <NUM> extends between the upper and lower surfaces <NUM>, <NUM> and connects to the posterior and anterior portions <NUM>, <NUM>. The implantable interbody device <NUM> may include a central opening or lumen <NUM> extending between the upper and lower surfaces <NUM>, <NUM> to facilitate bony ongrowth and bony ingrowth or fusion between adjacent bone segments, such as vertebral bodies. If so desired, the opening <NUM> may be used to receive and hold bone graft material to further enhance the bone fusion process.

The implantable device <NUM> shown in <FIG>, <FIG> include a porous lattice or mesh component <NUM> that can be incorporated within the solid structural component <NUM>. For instance, as shown in <FIG>, the implantable device <NUM> may have a solid structural component <NUM> with open spaces that can be filled with the porous component <NUM>, as shown in <FIG>, <FIG>. The combination and resultant device <NUM> provides a porous component all around the solid structural component <NUM> such as on the sidewalls <NUM> and on the top and bottom surfaces <NUM>, <NUM>. The lower surface <NUM> may include the same type of porous lattice or porous network component <NUM> integrated therein. Accordingly, the implantable interbody device <NUM> of <FIG> incorporates the principles of a network of pores and solid surfaces that is shown in <FIG> to create an improved fusion facilitating device <NUM> not heretofore seen.

Since the porous component is interconnected to the solid component, greater integration is achieved than with conventional textured coatings, titanium spray coatings, or surface roughenings. These additional enhancements are considered optional now. For example, the solid surfaces of the device <NUM> may be further coated or provided with surface roughenings or textured features. As shown in <FIG>, the solid scaffold structure <NUM> may be formed with a surface texture, and may therefore provide an outer surface that is textured, such as a roughened texture or one with discrete geometric protrusions, to enhance surface attachment.

The extensive porous lattice areas <NUM> that are engineered to extend all the way around the device <NUM> allow for more interaction with bone than with conventional treatment methods. Such features are possible for metallic, metallic alloy or polymeric devices based on layer-by-layer deposition manufacturing techniques like 3D printing or selective layer melting (SLM) of metal, metal alloy or polymer. And since the entire device <NUM> may be formed of metal, metal alloy or polymer, no additional visualization markers are necessary for visualization. Because the devices <NUM> are created in a single process without the need for connecting subcomponents together, one of the key benefits of the devices is that the interface between the porous lattice areas <NUM> and the upper surface <NUM>, lower surface <NUM> or sidewalls <NUM> is seamless and void of mechanical or chemical bonding, adding to the overall strength of the devices <NUM>. For perspective, <FIG> illustrates the device <NUM> with the porous lattice structure <NUM> removed, leaving the solid part of the device only. Thus, the porous lattice structure <NUM> is surrounded by a solid perimeter structure for strength. The porous lattice structure <NUM> can comprise randomized cell/pore size and cell/pore structure or geometry, while the unit cell structure (i.e., the structure of the porous lattice structure <NUM>) is based on a unique lightweight structure such as a dodecahedron. All of these features create a more organicappearing and behaving environment that is ideal for bone healing and bone growth.

In some embodiments, the sidewalls <NUM> may be concave to create a unique C- or I-beam shape when viewed in cross-section, which serves to enhance support of the endplates and reduce risk of subsidence, while also being able to promote a lightweight, lower stiffness structure. This unique C- or I-beam cross-sectional shape of the sidewalls also helps to enhance support of any graft material contained within the central opening <NUM> or of biologics formed to nest within this donut shaped lumen. The sidewalls <NUM> and lumens together may be radiused in such a way to create a self-supporting arch and other geometries to reduce the need for additional supports during the manufacturing process, such as when 3D printing.

To facilitate ease of insertion, the posterior portion, or leading end <NUM> may be tapered or otherwise shaped for concomitant distraction of soft tissue during insertion. For example, the posterior portion <NUM> may be a sharp, bullet shaped nose or tip <NUM>. The unique geometry of the device <NUM> including this sharpened tip <NUM> supports reduced insertion forces, and may also help to separate tissue during the insertion. This can be helpful, for example, where scar tissue or other obstructions are present at the implantation site, or where there is stenosis and/or some other anatomic anomaly such as where the endplates have grown together.

In the embodiment of <FIG>, the device <NUM> may have an indicator nose through hole <NUM>. The indicator nose through hole <NUM> may be configured for detection and may be used as a visual aid, such as an x-ray indicator. In addition, as shown in <FIG>, additional visual aids such as x-ray indicators may be present <NUM> in the device <NUM> to assist with the navigation and orientation of the device <NUM> during implantation. Furthermore, the device <NUM> may include an "I" beam <NUM> that may serve as an x-ray marker for assistance with visualization and spatial orientation.

The anterior portion, or trailing end <NUM> of the implantable interbody device <NUM> can include holes <NUM> for receiving fixation elements, such as for example, bone screws, and a hole <NUM> for receiving an insertion instrument. The hole <NUM> may be threaded, as shown in <FIG>. In the embodiment shown, the implantable interbody device <NUM> can include two screw holes <NUM>, one extending superiorly and one extending inferiorly. In other embodiments, instead of having one superior angled hole and one inferior angled hole in the device <NUM> as shown, the implantable device <NUM> may have two superior angled holes, or may be configured to have two inferior angled holes. One skilled in the art will appreciate that the implantable device <NUM> may comprise any number of holes at any location on the device <NUM>, or may have no screw holes at all, as shown in the embodiment of <FIG>.

The holes <NUM> provide a path through which securing means (e.g., fixation elements such as bone screws) may be inserted so as to secure the device <NUM> to respective superior and inferior vertebral bodies. The holes <NUM> may be configured to accommodate a variety of securing means, such as screws, pins, staples, or any other suitable fastening device. In one embodiment, the fixation screws may be self-tapping and/or self-drilling and may be of a bone-screw-type, such as those well known to skilled artisans. The screws can be sized and shaped for unicortical or bicortical bone fixation.

Further, in some embodiments, if so desired the holes <NUM> of the implantable interbody device <NUM> may be configured to permit a predetermined amount of screw toggle (i.e., angular skew) and enable a lag effect when the fixation screw is inserted and resides inside the hole or lumen <NUM>. In other words, the holes <NUM> permit a certain degree of nutation by the screw and thus the screws may toggle from one position to one or more different positions, for instance, during subsidence. For instance, holes <NUM> may be configured with a conical range of motion (i.e., angular clearance) of about <NUM> to about <NUM> degrees, although it is contemplated that an even larger range may be possible such as <NUM> to <NUM> degrees, or <NUM> to <NUM> degrees. In one embodiment, the range is about <NUM> to <NUM> degrees. It is also believed that the predetermined screw toggle (permitted by the clearance between the lumen, or hole <NUM> and the screw) promotes locking of the screw to the device <NUM> after subsidence subsequent to implantation. Alternatively, the holes <NUM> of the device <NUM> may be configured with little or no clearance to achieve rigid fixation, for example, when the device <NUM> is to be implanted into sclerotic bone. According to one aspect of the disclosure, in some embodiments, the screw holes may be hourglass shaped so as to facilitate manufacturing by SLM, E-beam or 3D printing. Further, the screw holes <NUM> may include a screw hole indicator groove, screw hole direction indicator arrow, screw hole direction indicator arrow, a reverse chamfer or overhang feature, countersink, visual response feedback feature, and/or tactile response feedback feature, similar to the screw holes described in <CIT>, now U. Patent Application Publication No. <CIT>.

In some embodiments, the implantable interbody device <NUM> may have non-parallel upper and lower surfaces <NUM>, <NUM> to form a wedge-shaped body. As shown in <FIG>, the device <NUM> may have a sloped or tapered profile such that one sidewall <NUM> has a greater height h<NUM> than the height h<NUM> of the opposed sidewall <NUM>. The upper and lower surfaces <NUM>, <NUM> thus are configured such that they are angled relative to one another. However, one skilled in the art will appreciate that the implantable interbody device <NUM> may also be provided with parallel upper and lower surfaces <NUM>, <NUM>. The implantable interbody device <NUM> may have any suitable shape or size to allow it to be used under lordotic or kyphotic conditions. For instance, in one example, the implantable interbody device <NUM> may have a <NUM> degree lordotic profile from an anterior-posterior (A-P) view.

<FIG> illustrate another exemplary embodiment of an implantable interbody device <NUM>' that may be implanted in the intervertebral space between vertebral bodies by a lateral approach, without the need for additional screw fixation. The implantable interbody device <NUM>' shares similar features to the implantable interbody device <NUM> of <FIG>, with like features having the same reference number followed by the symbol " ' " for convenient reference. Like the implantable interbody device <NUM> previously described, device <NUM>' may also be employed in the lumbar or thoracic regions.

The implantable interbody device <NUM>' may include posterior and anterior portions <NUM>', <NUM>' and upper and lower surfaces <NUM>', <NUM>' profiled to correspond with the profile of any bone material to which they are to be secured. Upper and lower surfaces <NUM>', <NUM>' may be flat or planar, or may be domed or convexly curved. A pair of sidewalls <NUM>' extends between the upper and lower surfaces <NUM>', <NUM>' and connects to the posterior and anterior portions <NUM>', <NUM>'. The implantable interbody device <NUM>' may include a central opening or lumen <NUM>' extending between the upper and lower surfaces <NUM>', <NUM>' to facilitate bony ongrowth and/or bony ingrowth or fusion between adjacent bone segments, such as vertebral bodies. If so desired, the opening <NUM>' may be used to receive and hold bone graft material to further enhance the bone fusion process.

The implantable device <NUM>' shown in <FIG>, <FIG> may include a porous lattice or mesh component <NUM>' that can be incorporated within the solid structural component <NUM>' similar to implantable device <NUM> described above.

In some embodiments, the sidewalls <NUM>' may be concave to create a unique C- or I-beam shape, and the sidewalls <NUM>' and lumens together may be radiused in such a way to create a self-supporting arch and other geometries to reduce the need for additional supports during the manufacturing process, such as when 3D printing. Like implantable device <NUM>, the posterior portion, or leading end <NUM>' may be tapered or otherwise shaped for concomitant distraction of soft tissue during insertion. For example, the posterior portion <NUM>' may be a sharp, bullet shaped nose or tip <NUM>'. In the embodiment of <FIG>, the device <NUM>' may have an indicator nose through hole <NUM>'. The indicator nose through hole <NUM>' may be configured for detection and may be used as a visual aid, such as an x-ray indicator. In addition, as shown in <FIG>, additional visual aids such as x-ray indicators may be present <NUM>' in the device <NUM>' to assist with the navigation and orientation of the device <NUM> during implantation. Furthermore, the device <NUM>' may include an "I" beam <NUM>' that may serve as an x-ray marker for assistance with visualization and spatial orientation.

Unlike implantable device <NUM>, the implantable device <NUM>' of the present embodiment does not include any screw holes at its anterior portion, or trailing end <NUM>'. However, similar to implantable device <NUM>, the implantable device <NUM>' of the present embodiment may include hole <NUM>' for receiving an insertion instrument. The hole <NUM>' may be threaded, as shown in <FIG>, similar to the one shown and described above for implantable device <NUM>.

As shown in <FIG>, <FIG> and <FIG>, exemplary embodiments of implantable spinal fusion or interbody devices <NUM>, <NUM>' configured for midline insertion into the spine can be provided in accordance with the principles of the present disclosure.

<FIG> and <FIG> illustrate an exemplary embodiment of an implantable spinal fusion or implantable interbody device <NUM> configured for midline insertion into the spine. The implantable device <NUM> may be implanted in the intervertebral space between vertebral bodies and secured to the vertebral bodies with fixation screws. The implantable interbody device <NUM> shown in <FIG> and <FIG> may be employed in the lumbar or thoracic regions by a midline surgical approach.

The implantable interbody device <NUM> may include posterior and anterior portions <NUM>, <NUM> and upper and lower surfaces <NUM>, <NUM> profiled to correspond with the profile of any bone material to which they are to be secured. Upper and lower surfaces <NUM>, <NUM> may be flat or planar, or may be domed or convexly curved. In one embodiment, the implantable device <NUM> defines a generally wedge shaped structure suitable for a posterior midline insertion approach. As can be seen in <FIG>, <FIG>, the device <NUM> may have an overall trapezoidal shape. Curved sidewalls <NUM> that extend from the anterior portion <NUM> intersect with posterior portion <NUM> at posterolateral corners <NUM>. The corners of the device, including the posterolateral corners <NUM>, may be rounded, smooth or curved, as shown, to avoid marked edges and to provide overall smoothness to the implant profile and prevent undesirable damage to surrounding tissue. The device <NUM>, however, may have other shapes depending on the desired implantation site.

Furthermore, edges of the device <NUM> may be shaped so as to cooperate with insertion tools to minimize unintended distraction of the vertebral bodies between which the device <NUM> is being positioned during implantation. For example, as shown in <FIG>, the implantable device <NUM> may include grooves or side cutouts <NUM> to allow a surface for receiving an insertion tool. To facilitate ease of insertion, the posterior portion, or leading end <NUM> may have a smooth, tapered or angled edge <NUM> or otherwise shaped edge for concomitant distraction of soft tissue during insertion.

The implantable interbody device <NUM> may include a central opening or lumen <NUM> extending between the upper and lower surfaces <NUM>, <NUM> to facilitate bony ongrowth and bony ingrowth or fusion between adjacent bone segments, such as vertebral bodies. If so desired, the opening <NUM> may be used to receive and hold bone graft material to further enhance the bone fusion process.

Like device <NUM>, the implantable interbody device <NUM> may include a porous lattice or mesh component <NUM> that can be incorporated within the solid scaffold structure <NUM> of the device <NUM>. For instance, as shown in <FIG>, the implantable device <NUM> may have a solid structural component <NUM> within and on which a porous component <NUM> may be incorporated, as seen in <FIG>, to form a combination and resultant device <NUM> which provides a porous component <NUM> within a solid structural component <NUM>, as shown in <FIG>. Accordingly, the implantable interbody device <NUM> of <FIG> incorporate the same principles of a network of pores and solid surfaces as the device <NUM> above, to create an improved fusion facilitating device <NUM> not heretofore seen.

Since the porous component is interconnected to the solid component, greater integration is achieved than with conventional textured coatings, titanium spray coatings, or surface roughenings. These additional surface enhancements are considered optional. For instance, the solid surfaces of the device <NUM> may be further coated or provided with surface features like roughenings or textures. As shown in <FIG>, the solid scaffold structure <NUM> may be formed with a surface texture, and may therefore provide an outer surface that is textured, such as a roughened texture or one with discrete geometric protrusions, to enhance surface attachment.

As with device <NUM>, the extensive porous lattice areas <NUM> that are engineered to extend all the way around the device <NUM> allow for more interaction with bone than with convention enhancement methods. Such features are possible for metallic, metallic alloy or polymeric devices based on layer-by-layer deposition manufacturing techniques like 3D printing or selective layer melting (SLM) of metal, metal alloy or polymer. And since the entire device <NUM> may be formed of metal, metal alloy or polymer, no additional visualization markers are necessary for visualization. Because the devices <NUM> are created in a single process without the need for connecting subcomponents together, one of the key benefits of the devices is that the interface between the porous lattice areas <NUM> and the upper surface <NUM>, lower surface <NUM> or sidewalls <NUM> is seamless and void of mechanical or chemical bonding, adding to the overall strength of the devices <NUM>. As shown in <FIG>, the body of device <NUM> incorporates the porous lattice or mesh structures <NUM> into itself. The porous lattice structure <NUM> is not a separate panel that is added onto the body, but is integrated into the body of the device <NUM>.

In some embodiments, the sidewalls <NUM> may be concave to create a unique C - or I - beam shape <NUM> when viewed in cross-section, which serves to enhance support of the endplates and reduce risk of subsidence, while also being able to promote a lightweight, lower stiffness structure. This unique C- or I-beam cross-sectional shape of the sidewalls <NUM> also helps to enhance support of any graft material contained within the central opening <NUM> or of biologics formed to nest within this donut shaped lumen <NUM>. The sidewalls <NUM> and lumens <NUM> together may be radiused as shown in <FIG> in such a way to create a self-supporting arch and other geometries to reduce the need for additional supports during the manufacturing process, such as when 3D printing.

In some embodiments, the implantable interbody device <NUM> may have non-parallel upper and lower surfaces <NUM>, <NUM> to form a wedge-shaped body, if so desired. However, one skilled in the art will appreciate that the implantable interbody device <NUM> may also be provided with parallel upper and lower surfaces <NUM>, <NUM>. The implantable interbody device <NUM> may have any suitable shape or size to allow it to be used under lordotic or kyphotic conditions, similar to device <NUM> above.

Similar to device <NUM>, the anterior portion, or trailing end <NUM> of the implantable interbody device <NUM> can include holes <NUM> for receiving fixation elements, such as for example, bone screws to secure the device <NUM> to adjacent bone tissue. In the embodiment shown, the device <NUM> can include three holes <NUM>, such as one hole being centrally located (i.e., along the center line), and two laterally located (i.e., beside the center line. ) Without compromising stability, the lateral holes <NUM> should be located in a manner that avoids the need to retract vessels during surgery. It has been postulated that extended retraction of vessels during surgery may lead to greater chances for complications to the patient. The lateral holes <NUM> should also be positioned so as to provide easier visibility of the surrounding implantation site for the surgeon. One skilled in the art will appreciate that the device <NUM> may comprise any number of holes at any location on the device <NUM>, or may have no screw holes at all, as shown in the embodiments of <FIG>.

The holes <NUM> of device <NUM> are similar to those holes <NUM> of device <NUM> and share the same features described above. Accordingly, holes <NUM> also provide a path through which securing means (e.g., fixation elements such as bone screws) may be inserted so as to secure the device <NUM> to respective superior and inferior vertebral bodies. The holes <NUM> may be configured to accommodate a variety of securing means, such as screws, pins, staples, or any other suitable fastening device. In one embodiment, the fixation screws may be self-tapping and/or self-drilling and may be of a bone-screw-type, such as those well known to skilled artisans. The screws can be sized and shaped for unicortical or bicortical bone fixation. In addition, in some embodiments, the screw holes <NUM> may be hourglass shaped. Furthermore, the screw holes <NUM> may include a screw hole indicator groove, screw hole direction indicator arrow, a reverse chamfer or overhang feature, countersink, visual response feedback feature, and/or tactile response feedback feature, similar to the screw holes described in <CIT>, now U. Patent Application Publication No. <CIT>.

<FIG> illustrate another exemplary embodiment of an implantable interbody device <NUM>' that may be implanted in the intervertebral space between vertebral bodies by a midline approach, without the need for additional screw fixation. The implantable interbody device <NUM>' shares similar features to the implantable interbody device <NUM> of <FIG> and <FIG>, with like features having the same reference number followed by the symbol " ' " for convenient reference. Like the implantable interbody device <NUM> previously described, device <NUM>' may also be employed in the lumbar or thoracic regions.

The implantable interbody device <NUM>' may include posterior and anterior portions <NUM>', <NUM>' and upper and lower surfaces <NUM>', <NUM>' profiled to correspond with the profile of any bone material to which they are to be secured. Upper and lower surfaces <NUM>', <NUM>' may be flat or planar, or may be domed or convexly curved. In one embodiment, the implantable device <NUM>' defines a generally wedge shaped structure suitable for a posterior midline insertion approach. As can be seen in <FIG>, <FIG>, the device <NUM>' may have an overall trapezoidal shape. Curved sidewalls <NUM>' that extend from the anterior portion <NUM>' intersect with posterior portion <NUM>' at posterolateral corners <NUM>'. The corners of the device <NUM>', including the posterolateral corners <NUM>', may be rounded, smooth or curved, as shown, to avoid marked edges and to provide overall smoothness to the implant profile and prevent undesirable damage to surrounding tissue. The device <NUM>', however, may have other shapes depending on the desired implantation site.

Furthermore, edges of the device <NUM>' may be shaped so as to cooperate with insertion tools to minimize unintended distraction of the vertebral bodies between which the device <NUM>' is being positioned during implantation. For example, as shown in <FIG>, the implantable device <NUM>' may include grooves or side cutouts <NUM>' to allow a surface for receiving an insertion tool. To facilitate ease of insertion, the posterior portion, or leading end <NUM>' may have a smooth, tapered or angled edge <NUM>' or otherwise shaped edge for concomitant distraction of soft tissue during insertion.

The implantable interbody device <NUM>' may include a central opening or lumen <NUM>' extending between the upper and lower surfaces <NUM>', <NUM>' to facilitate bony ongrowth and bony ingrowth or fusion between adjacent bone segments, such as vertebral bodies. If so desired, the opening <NUM>' may be used to receive and hold bone graft material to further enhance the bone fusion process.

Like device <NUM>, the implantable interbody device <NUM>' may include a porous lattice or mesh component <NUM>' that can be incorporated within the solid scaffold structure <NUM>' of the device <NUM>'. For instance, as shown in <FIG>, the implantable device <NUM>' may have a solid structural component <NUM>' within and on which a porous component <NUM>' may be incorporated, as seen in <FIG>, to form a combination and resultant device <NUM>' which provides a porous component <NUM>' within a solid structural component <NUM>', as shown in <FIG>. Accordingly, the implantable interbody device <NUM>' of <FIG> incorporate the same principles of a network of pores and solid surfaces as the device <NUM> above, to create an improved fusion facilitating device <NUM>' not heretofore seen. Since the porous component is interconnected to the solid component, greater integration is achieved than with conventional textured coatings, titanium spray coatings, or surface roughenings. These additional surface enhancements are considered optional. For instance, the solid surfaces of the device <NUM>' may be further coated or provided with surface features like roughenings or textures. As shown in <FIG>, the solid scaffold structure <NUM>' may be formed with a surface texture, and may therefore provide an outer surface that is textured, such as a roughened texture or one with discrete geometric protrusions, to enhance surface attachment.

In some embodiments, the sidewalls <NUM>' may be concave to create a unique C - or I - beam shape when viewed in cross-section, which serves to enhance support of the endplates and reduce risk of subsidence, while also being able to promote a lightweight, lower stiffness structure. This unique C- or I-beam cross-sectional shape of the sidewalls <NUM>' also helps to enhance support of any graft material contained within the central opening <NUM>' or of biologics formed to nest within this donut shaped lumen. The sidewalls and lumens together may be radiused in such a way to create a self-supporting arch and other geometries to reduce the need for additional supports during the manufacturing process, such as when 3D printing.

In some embodiments, the implantable interbody device <NUM>' may have non-parallel upper and lower surfaces <NUM>', <NUM>' to form a wedge-shaped body, if so desired. However, one skilled in the art will appreciate that the implantable interbody device <NUM>' may also be provided with parallel upper and lower surfaces <NUM>', <NUM>'. The implantable interbody device <NUM>' may have any suitable shape or size to allow it to be used under lordotic or kyphotic conditions, similar to device <NUM> above.

Unlike implantable device <NUM>, the implantable device <NUM>' of the present embodiment does not include any angular screw holes at its anterior portion, or trailing end <NUM>'. Instead, the implantable device <NUM>' of the present embodiment may include holes <NUM>' as shown in <FIG>, <FIG>, and <FIG>. The hole <NUM>' may be threaded, as shown. These threaded holes <NUM>' may be used for attachment of an inserter tool, or a threaded nut or screw to secure a graft component. The additional thread form enables easy oblique insertion during surgery. In addition, the threaded screw holes <NUM>' allow for a larger graft area in the central opening <NUM>'. Additionally, the anterior portion <NUM>' may include regions <NUM>' where the porous component <NUM>' may be provided, as shown in <FIG>.

As shown in <FIG> and <FIG>, exemplary embodiments of an implantable spinal fusion or interbody device <NUM>, <NUM>' configured for the cervical spine can be provided in accordance with the principles of the present disclosure.

<FIG> illustrate an exemplary embodiment of an implantable interbody device <NUM> that may be implanted in the intervertebral space between vertebral bodies of the cervical spine and secured to the vertebral bodies with fixation screws. The device <NUM> may be sized and shaped to allow stacking at different spinal levels.

The implantable interbody device <NUM> adopts similar features from the implantable interbody device <NUM> described above. Accordingly the device <NUM> may include posterior and anterior portions <NUM>, <NUM> and upper and lower surfaces <NUM>, <NUM> profiled to correspond with the profile of any bone material to which they are to be secured. Upper and lower surfaces <NUM>, <NUM> may be flat or planar, or may be domed or convexly curved. In one embodiment, the implantable device <NUM> defines a generally wedge shaped structure suitable for a posterior midline insertion approach. As can be seen in <FIG>, <FIG>, the device <NUM> may have an overall trapezoidal shape. Curved sidewalls <NUM> that extend from the anterior portion <NUM> intersect with posterior portion <NUM> at posterolateral corners <NUM> similar to device <NUM>. The corners of the device <NUM>, including the posterolateral corners <NUM>, may be rounded, smooth or curved, as shown, to avoid marked edges and to provide overall smoothness to the implant profile and prevent undesirable damage to surrounding tissue. The device <NUM>, however, may have other shapes depending on the desired implantation site.

Furthermore, edges of the device <NUM> may be shaped so as to cooperate with insertion tools to minimize unintended distraction of the vertebral bodies between which the device <NUM> is being positioned during implantation. To facilitate ease of insertion, the posterior portion, or leading end <NUM> may have a smooth, tapered or angled edge <NUM> or otherwise shaped edge for concomitant distraction of soft tissue during insertion.

The implantable interbody device <NUM> may include a central opening or lumen <NUM> extending between the upper and lower surfaces <NUM>, <NUM> to facilitate bony ongrowth and/or bony ingrowth or fusion between adjacent bone segments, such as vertebral bodies. If so desired, the opening <NUM> may be used to receive and hold bone graft material to further enhance the bone fusion process.

The implantable interbody device <NUM> may include a porous lattice or mesh component <NUM> that can be incorporated within the solid scaffold structure <NUM> of the device <NUM>. For instance, as shown in <FIG>, the implantable device <NUM> may have a solid structural component <NUM> within and on which a porous component <NUM> may be incorporated, as seen in <FIG>, to form a combination and resultant device <NUM> which provides a porous component <NUM> within a solid structural component <NUM>, as shown in <FIG>. Accordingly, the implantable interbody device <NUM> of <FIG> incorporate the same principles of a network of pores and solid surfaces as the devices <NUM>, <NUM> above, to create an improved fusion facilitating device <NUM> for the cervical spine not heretofore seen.

Like devices <NUM>, <NUM>, the extensive porous lattice areas <NUM> that are engineered to extend all the way around the device <NUM> allow for more interaction with bone than with convention enhancement methods. Such features are possible for metallic, metallic alloy or polymeric devices based on layer-by-layer deposition manufacturing techniques like 3D printing or selective layer melting (SLM) of metal, metal alloy or polymer. And since the entire device <NUM> may be formed of metal, metal alloy or polymer, no additional visualization markers are necessary for visualization. Because the devices <NUM> are created in a single process without the need for connecting subcomponents together, one of the key benefits of the devices is that the interface between the porous lattice areas <NUM> and the upper surface <NUM>, lower surface <NUM> or sidewalls <NUM> is seamless and void of mechanical or chemical bonding, adding to the overall strength of the devices <NUM>. As shown, the body of device <NUM> incorporates the porous lattice or mesh structures <NUM> into itself. The porous lattice structure <NUM> is not a separate panel that is added onto the body, but is integrated into the body of the device <NUM>.

In some embodiments, the implantable interbody device <NUM> may have non-parallel upper and lower surfaces <NUM>, <NUM> to form a wedge-shaped body. However, one skilled in the art will appreciate that the implantable interbody device <NUM> may also be provided with parallel upper and lower surfaces <NUM>, <NUM>. The implantable interbody device <NUM> may have any suitable shape or size to allow it to be used under lordotic or kyphotic conditions, similar to devices <NUM>, <NUM> above.

Also like devices <NUM>, <NUM>, the anterior portion, or trailing end <NUM> of the implantable interbody device <NUM> can include holes <NUM> for receiving fixation elements, such as for example, bone screws to secure the device <NUM> to adjacent bone tissue. In the embodiment shown, the device <NUM> may include three holes <NUM>, such as one hole being centrally located (i.e., along the center line), and two laterally located (i.e., beside the center line. ) Without compromising stability, the lateral holes <NUM> should be located in a manner that avoids the need to retract vessels during surgery. It has been postulated that extended retraction of vessels during surgery may lead to greater chances for complications to the patient. The lateral holes <NUM> should also be positioned so as to provide easier visibility of the surrounding implantation site for the surgeon. One skilled in the art will appreciate that the device <NUM> may comprise any number of holes at any location on the device <NUM>, or may have no screw holes at all, as shown in the embodiments of <FIG>.

The holes <NUM> of device <NUM> are similar to those holes <NUM>, <NUM> of devices <NUM>, <NUM> and share the same features described above. Accordingly, holes <NUM> also provide a path through which securing means (e.g., fixation elements such as bone screws) may be inserted so as to secure the device <NUM> to respective superior and inferior vertebral bodies. The holes <NUM> may be configured to accommodate a variety of securing means, such as screws, pins, staples, or any other suitable fastening device. In one embodiment, the fixation screws may be self-tapping and/or self-drilling and may be of a bone-screw-type, such as those well known to skilled artisans. The screws can be sized and shaped for unicortical or bicortical bone fixation. In addition, in some embodiments, the screw holes <NUM> may be hourglass shaped. Furthermore, the screw holes <NUM> may include a screw hole indicator groove, screw hole direction indicator arrow, a reverse chamfer or overhang feature, countersink, visual response feedback feature, and/or tactile response feedback feature, similar to the screw holes described in <CIT>, now U. Patent Application Publication No. <CIT>.

According to other aspects of the disclosure, the device <NUM> may include visual cues <NUM> like arrows to indicate screw trajectory. The unique hybrid scaffold structure of the device <NUM> enables better graft retention with its concavity. Furthermore, as shown, the textured exterior surface enhances bone attachment and bone fusion. As with devices <NUM>, <NUM>, the device may further include additional surface enhancements such as coatings, surface textures or surface roughenings.

<FIG> illustrate another exemplary embodiment of an implantable interbody device <NUM>' that may be implanted in the intervertebral space between vertebral bodies of the cervical spine, without the need for additional screw fixation. The implantable interbody device <NUM>' shares similar features to the implantable interbody device <NUM> of <FIG>, with like features having the same reference number followed by the symbol " ' " for convenient reference.

Similar to implantable interbody device <NUM>, the implantable interbody device <NUM>' may include posterior and anterior portions <NUM>', <NUM>' and upper and lower surfaces <NUM>', <NUM>' profiled to correspond with the profile of any bone material to which they are to be secured. Upper and lower surfaces <NUM>', <NUM>' may be flat or planar, or may be domed or convexly curved. In one embodiment, the implantable device <NUM>' defines a generally wedge shaped structure suitable for a posterior midline insertion approach. As can be seen in <FIG>, <FIG>, the device <NUM>' may have an overall trapezoidal shape. Curved sidewalls <NUM>' that extend from the anterior portion <NUM>' intersect with posterior portion <NUM>' at posterolateral corners <NUM>'. The corners of the device <NUM>', including the posterolateral corners <NUM>', may be rounded, smooth or curved, as shown, to avoid marked edges and to provide overall smoothness to the implant profile and prevent undesirable damage to surrounding tissue. The device <NUM>', however, may have other shapes depending on the desired implantation site. The device <NUM>', however, may have other shapes depending on the desired implantation site.

Furthermore, edges of the device <NUM>' may be shaped so as to cooperate with insertion tools to minimize unintended distraction of the vertebral bodies between which the device <NUM>' is being positioned during implantation. To facilitate ease of insertion, the posterior portion, or leading end <NUM>' may have a smooth, tapered or angled edge <NUM>' or otherwise shaped edge for concomitant distraction of soft tissue during insertion.

The implantable interbody device <NUM>' may include a central opening or lumen <NUM>' extending between the upper and lower surfaces <NUM>', <NUM>' to facilitate bony ongrowth and/or bony ingrowth or fusion between adjacent bone segments, such as vertebral bodies. If so desired, the opening <NUM>' may be used to receive and hold bone graft material to further enhance the bone fusion process.

The implantable interbody device <NUM>' may include a porous lattice or mesh component <NUM>' that can be incorporated within the solid scaffold structure <NUM>' of the device <NUM>'. For instance, as shown in <FIG>, the implantable device <NUM>' may have a solid structural component <NUM>' within and on which a porous component <NUM>' may be incorporated, as seen in <FIG>, to form a combination and resultant device <NUM>' which provides a porous component <NUM>' within a solid structural component <NUM>', as shown in <FIG>. Accordingly, the implantable interbody device <NUM>' of <FIG> incorporate the same principles of a network of pores and solid surfaces as the devices <NUM>, <NUM> above, to create an improved fusion facilitating device <NUM>' for the cervical spine not heretofore seen.

Since the porous component is interconnected to the solid component, greater integration is achieved than with conventional textured coatings, titanium spray coatings, or surface roughenings. These additional surface enhancements are considered optional. For instance, the solid surfaces of the device <NUM>' may be further coated or provided with surface features like roughenings or textures. As shown in <FIG>, the solid scaffold structure <NUM>' may be formed with a surface texture, and may therefore provide an outer surface that is textured, such as a roughened texture or one with discrete geometric protrusions, to enhance surface attachment.

Like devices <NUM>, <NUM>, the extensive porous lattice areas <NUM>' that are engineered to extend all the way around the device <NUM>' allow for more interaction with bone than with convention enhancement methods. Such features are possible for metallic, metallic alloy or polymeric devices based on layer-by-layer deposition manufacturing techniques like 3D printing or selective layer melting (SLM) of metal, metal alloy or polymer. And since the entire device <NUM>' may be formed of metal, metal alloy or polymer, no additional visualization markers are necessary for visualization. Because the devices <NUM>' are created in a single process without the need for connecting subcomponents together, one of the key benefits of the devices is that the interface between the porous lattice areas <NUM>' and the upper surface <NUM>', lower surface <NUM>' or sidewalls <NUM>' is seamless and void of mechanical or chemical bonding, adding to the overall strength of the devices <NUM>'. As shown, the body of device <NUM>' incorporates the porous lattice or mesh structures <NUM>' into itself. The porous lattice structure <NUM>' is not a separate panel that is added onto the body, but is integrated into the body of the device <NUM>'.

In some embodiments, the sidewalls <NUM>' may be concave to create a unique C- or I-beam shape when viewed in cross-section, which serves to enhance support of the endplates and reduce risk of subsidence, while also being able to promote a lightweight, lower stiffness structure. This unique C- or I-beam cross-sectional shape of the sidewalls also helps to enhance support of any graft material contained within the central opening <NUM>' or of biologics formed to nest within this donut shaped lumen. The sidewalls <NUM>' and lumens together may be radiused in such a way to create a self-supporting arch and other geometries to reduce the need for additional supports during the manufacturing process, such as when 3D printing.

In some embodiments, the implantable interbody device <NUM>' may have non-parallel upper and lower surfaces <NUM>', <NUM>' to form a wedge-shaped body. However, one skilled in the art will appreciate that the implantable interbody device <NUM>' may also be provided with parallel upper and lower surfaces <NUM>', <NUM>'. The implantable interbody device <NUM>' may have any suitable shape or size to allow it to be used under lordotic or kyphotic conditions, similar to devices <NUM>, <NUM> above.

Unlike implantable device <NUM>, the implantable device <NUM>' of the present embodiment does not include any angular screw holes at its anterior portion, or trailing end <NUM>'. Instead, the implantable device <NUM>' of the present embodiment may include a holes <NUM>' as shown in <FIG>, <FIG>. The hole <NUM>' may be threaded, as shown. These threaded holes <NUM>' may be used for attachment of an inserter tool, or a threaded nut or screw to secure a graft component. The additional thread form enables easy oblique insertion during surgery. In addition, the threaded screw holes <NUM>' allow for a larger graft area in the central opening <NUM>'. Additionally, the anterior portion <NUM>' may include regions <NUM>' where the porous component <NUM>' may be provided, as shown in <FIG>.

As shown in <FIG> and <FIG>, exemplary embodiments of implantable spinal fusion or interbody devices <NUM>, <NUM>' configured for lateral-oblique insertion into the contra lateral and posterior space of the spine can be provided in accordance with the principles of the present disclosure. The implantable interbody devices <NUM>, <NUM>' shown in <FIG> and <FIG> may be employed in the lumbar or thoracic regions in a lateral-oblique surgical approach.

<FIG> illustrate an exemplary embodiment of an implantable interbody device <NUM> configured for lateral-oblique insertion into the contra lateral and posterior space of the spine. The implantable device <NUM> may be implanted in the intervertebral space between vertebral bodies and secured to the vertebral bodies with fixation screws. As mentioned, the implantable interbody device <NUM> may be configured for insertion at an oblique angle into contra lateral and posterior space of the spine. The implantable interbody device <NUM> may be employed in the lumbar region of the spine. However, it is contemplated that the implantable interbody device <NUM> may be shaped and sized for use in other areas of the spine as well, such as the thoracic and the cervical region of the spine.

Additionally, while the devices <NUM> of the present disclosure are described as being inserted using an oblique angle approach, it is understood that the devices <NUM> may also be properly inserted using other techniques as well, including approaches that are not oblique angle approaches. For example, where the shape and geometry of the implantable interbody device <NUM> is suited for use in a clinical application but the oblique angle approach is not necessary or desired, then it is understood that the implantable interbody device <NUM> may be employed, without restriction to the particular surgical technique to insert the implantable interbody device <NUM>. In some instances, different spinal levels may require a different insertion approach but would still be able to utilize the devices <NUM> of the present disclosure. Therefore, the devices <NUM> may be used at multiple levels, whereby the implants may be inserted at these levels with different approaches.

Turning now to the drawings, according to one exemplary embodiment, the implantable interbody device <NUM> may include posterior and anterior portions <NUM>, <NUM>, and upper and lower surfaces <NUM>, <NUM> connected by two lateral walls or sidewalls 420a, 420b and an intermediate wall segment or sidewall 420c. Upper and lower surfaces <NUM>, <NUM> may be flat or planar, or may be domed or convexly curved. The two lateral walls or sidewalls 420a, 240b may converge into a nose or tip <NUM>. This nose or tip <NUM> may be rounded or tapered. Collectively, the three walls 420a, 420b, 420c may together form a generally triangular profile. However, as shown, one lateral wall 420b may be greater in length than the other lateral wall 420a, creating a shark's fin-like shape. Additionally, the walls collectively may also form a rounded or approximately rectangular shape, particularly if one or more of the walls is curved or angled itself.

As shown, the implantable interbody device <NUM> may define a generally wedge shaped or anatomically shaped structure, such as a structure having a sharks fin or arrowhead profile, to more closely match the surrounding anatomy of the implant site, for ease of insertion (i.e., to allow tissue distraction), and to be suitable for a tissue sparing or an oblique angular insertion approach. As can be further seen, the device <NUM> may have rounded edges and corners, particularly along its outer perimeter. The intermediate wall 420c may extend into convexly curved lateral walls 420a, 420b that intersect at posterolateral corners <NUM>. The posterolateral corners <NUM> may be rounded, as shown, to provide overall smoothness to the implant profile and prevent undesirable damage to surrounding tissue.

The implantable interbody device <NUM> may include a central opening or lumen <NUM> extending between the upper and lower surfaces <NUM>, <NUM> to facilitate bony ongrowth and bony ingrowth or fusion between adjacent bone segments, such as vertebral bodies. If so desired, the opening <NUM> may be used as a graft cavity to receive and hold bone graft material, or other biologically active materials like bone cement, bone void filler, bone substitute material, bone chips, demineralized bone matrix, and other similar materials. The implantable interbody device <NUM> may be configured in a way that optimizes the opening <NUM> such that the ratio of the cage or implant structure to the load bearing area is as large as possible. A graft containment porous groove may be provided within the opening <NUM> to contain graft material inside the graft cavity in the center of the device <NUM>. This groove may be machined along the wall of the cavity <NUM> to provide additional support in keeping the graft material secured during implantation. Further, the groove may be convex, such as to serve as a boss extending into the central lumen area. This groove may be provided on any of the devices <NUM>, <NUM>, <NUM>, <NUM> described herein.

Similar to previously described devices <NUM>, <NUM>, <NUM>, the implantable interbody device <NUM> may include bores or holes <NUM> to receive fixation elements such as fixation screws therethrough to secure the implantable interbody device <NUM> to adjacent bone tissue. Furthermore, the device <NUM> may include an opening <NUM> for receiving an insertion tool. This opening <NUM> may be threaded, as shown in <FIG> and as described above for device <NUM>. Alternatively, the interbody device <NUM> may be provided without any screw holes, such as in the embodiment shown in <FIG>.

The screw holes <NUM> of this device <NUM>, as well as the screw holes of the other previously described devices <NUM>, <NUM>, <NUM> may have a loft geometry surrounding it. Meaning, material may be removed around the screw holes <NUM> to facilitate screw insertion. Additionally, an indicator groove may be provided on each of the screw holes <NUM> to facilitate proper screw seating. This indicator groove may be a thin groove that is machined into the screw hole <NUM> so that it is only visible when the screw is fully seated and a split ring is engaged, for example. In one embodiment, the screw holes <NUM> may be configured to remain centered relative to the position of the device <NUM> as the height increases to allow for one introducer tool to capture the screw holes <NUM>. In another embodiment, the screw holes <NUM> may be configured to translate with the endplates during use. Other optional visualization assistance features within the screw hole <NUM> may include etchings, colored bands, or indicator arrows. In addition, the screw holes <NUM> may be hourglass shaped. Similar to the screw holes described above, screw holes <NUM> may include a screw hole indicator groove, screw hole direction indicator arrow, a reverse chamfer or overhang feature, countersink, visual response feedback feature, and/or tactile response feedback feature, similar to the screw holes described in <CIT>, now U. Patent Application Publication No. <CIT>.

Without compromising stability, the lateral holes <NUM> may be positioned in a manner that avoids the need to retract vessels during surgery. Extended retraction of vessels during surgery may lead to greater chances for complications to the patient. Furthermore, the screw holes <NUM> may be closely packed and angled so that the screws converge on the oblique line.

Similar to those devices <NUM>, <NUM>, <NUM> previously described, the implantable interbody device <NUM> may include a porous lattice or mesh component <NUM> within the solid scaffold structure <NUM> of the device <NUM>. For instance, the implantable device <NUM> may have a solid structural component <NUM> within and on which a porous component <NUM> may be incorporated, as seen in <FIG> and <FIG>, to form a combination and resultant device <NUM> which provides a porous component <NUM> within a solid structural component <NUM>. Accordingly, the implantable interbody device <NUM> may incorporate the same principles of a network of pores and solid surfaces as the devices <NUM>, <NUM>, <NUM> above, to create an improved fusion facilitating device <NUM> for the cervical spine not heretofore seen. Since the porous component is interconnected to the solid component, greater integration is achieved than with conventional textured coatings, titanium spray coatings, or surface roughenings. These additional surface enhancements are considered optional. For instance, the solid surfaces of the device <NUM> may be further coated or provided with surface features like roughenings or textures. Similar to the devices <NUM>, <NUM>, <NUM> previously described, the solid scaffold structure <NUM> may be formed with a surface texture, and may therefore provide an outer surface that is textured, such as a roughened texture or one with discrete geometric protrusions, to enhance surface attachment.

Like devices <NUM>, <NUM>, <NUM>, the extensive porous lattice areas <NUM> that are engineered to extend all the way around the device <NUM> allow for more interaction with bone than with convention enhancement methods. Such features are possible for metallic, metallic alloy or polymeric devices based on layer-by-layer deposition manufacturing techniques like 3D printing or selective layer melting (SLM) of metal, metal alloy or polymer. And since the entire device <NUM> may be formed of metal, metal alloy or polymer, no additional visualization markers are necessary for visualization. Because the devices <NUM> are created in a single process without the need for connecting subcomponents together, one of the key benefits of the devices is that the interface between the porous lattice areas <NUM> and the upper surface <NUM>, lower surface <NUM> or sidewalls <NUM> is seamless and void of mechanical or chemical bonding, adding to the overall strength of the devices <NUM>. As shown, the body of device <NUM> incorporates the porous lattice or mesh structures <NUM> into itself. The porous lattice structure <NUM> is not a separate panel that is added onto the body, but is integrated into the body of the device <NUM>.

In some embodiments, the sidewalls 420a, b, c may be concave to create a unique C- or I-beam shape when viewed in cross-section, which serves to enhance support of the endplates and reduce risk of subsidence, while also being able to promote a lightweight, lower stiffness structure. This unique C- or I-beam cross-sectional shape of the sidewalls also helps to enhance support of any graft material contained within the central opening <NUM> or of biologics formed to nest within this donut shaped lumen. The sidewalls 420a, b, c and lumens together may be radiused in such a way to create a self-supporting arch and other geometries to reduce the need for additional supports during the manufacturing process, such as when 3D printing.

In some embodiments, the implantable interbody device <NUM> may have non-parallel upper and lower surfaces <NUM>, <NUM> to form a wedge-shaped body. However, one skilled in the art will appreciate that the implantable interbody device <NUM> may also be provided with parallel upper and lower surfaces <NUM>, <NUM>. The implantable interbody device <NUM> may have any suitable shape or size to allow it to be used under lordotic or kyphotic conditions, similar to devices <NUM>, <NUM>, <NUM> above.

Similar to device <NUM>, the device <NUM> may have an indicator nose through hole <NUM>. The indicator nose through hole <NUM> may be configured for detection and may be used as a visual aid, such as an x-ray indicator. In addition, as shown in <FIG>, additional visual aids such as x-ray indicators may be present <NUM> in the device <NUM> to assist with the navigation and orientation of the device <NUM> during implantation. According to other aspects of the disclosure, the device <NUM> may include a center located "I" marker for visibility, which can be seen through the porous lattice or mesh structure <NUM>, similar to the "I" beam <NUM> of device <NUM> which may also serve as an x-ray marker. Further, the unique hybrid scaffold structure of the device <NUM> enables better graft retention with its concavity. The textured exterior surface enhances bone attachment and bone fusion. As with devices <NUM>, <NUM>, <NUM> the device <NUM> may further include additional surface enhancements such as coatings, surface textures or surface roughenings.

It will also be appreciated that the angular positioning of the various holes, as described above, allows the present device <NUM> to be of a relatively small size and therefore insertable from an oblique angular approach into the intervertebral spaces of the spine. Thus, it will be appreciated that the angular positioning of the holes can assist effective operation of the device <NUM> and the ability to "stack" implants in adjacent multilevel procedures without the securing means interfering with each other. Such a feature can be of major significance in some situations and applications.

<FIG> illustrate another exemplary embodiment of an implantable interbody device <NUM>' configured for lateral-oblique insertion into the contra lateral and posterior space of the spine. The implantable device <NUM>' may be implanted in the intervertebral space between vertebral bodies, without the need for additional screw fixation. Similar to device <NUM>, the implantable interbody device <NUM>' may be configured for insertion at an oblique angle into contra lateral and posterior space of the spine. The implantable interbody device <NUM>' may be employed in the lumbar region of the spine. However, it is contemplated that the implantable interbody device <NUM>' may be shaped and sized for use in other areas of the spine as well, such as the thoracic and the cervical region of the spine.

The implantable interbody device <NUM>' may include posterior and anterior portions <NUM>', <NUM>', and upper and lower surfaces <NUM>', <NUM>' connected by two lateral walls or sidewalls 420a', 420b' and intermediate wall segment or sidewall 420c'. Upper and lower surfaces <NUM>', <NUM>' may be flat or planar, or may be domed or convexly curved. The two lateral walls 420a', 240b' may converge into a nose or tip <NUM>'. This nose or tip <NUM>' may be rounded or tapered. Collectively, the three walls 420a', 420b', 420c' may together form a generally triangular profile. However, as shown, one sidewall 420b may be greater in length than the other sidewall 420a', creating a shark's fin-like shape. Additionally, the walls collectively may also form a rounded or approximately rectangular shape, particularly if one or more of the walls is curved or angled itself.

As shown, the implantable interbody device <NUM>' may define a generally wedge shaped or anatomically shaped structure, such as a structure having a sharks fin or arrowhead profile, to more closely match the surrounding anatomy of the implant site, for ease of insertion (i.e., to allow tissue distraction), and to be suitable for a tissue sparing or an oblique angular insertion approach. As can be further seen, the device <NUM>' may have rounded edges and corners, particularly along its outer perimeter. The intermediate wall 420c' may extend into convexly curved lateral walls 420a', 420b' that intersect at posterolateral corners <NUM>'. The posterolateral corners <NUM>' may be rounded, as shown, to provide overall smoothness to the implant profile and prevent undesirable damage to surrounding tissue.

The implantable interbody device <NUM>' may include a central opening or lumen <NUM>' extending between the upper and lower surfaces <NUM>', <NUM>' to facilitate bony ongrowth and bony ingrowth or fusion between adjacent bone segments, such as vertebral bodies. If so desired, the opening <NUM>' may be used as a graft cavity to receive and hold bone graft material, or other biologically active materials like bone cement, bone void filler, bone substitute material, bone chips, demineralized bone matrix, and other similar materials. The implantable interbody device <NUM>' may be configured in a way that optimizes the opening <NUM>' such that the ratio of the cage or implant structure to the load bearing area is as large as possible. A graft containment porous groove may be provided within the opening <NUM>' to contain graft material inside the graft cavity in the center of the device <NUM>'. This groove may be machined along the wall of the cavity <NUM>' to provide additional support in keeping the graft material secured during implantation. Further, the groove may be convex, such as to serve as a boss extending into the central lumen area. This groove may be provided on any of the devices described herein.

Similar to those devices <NUM>, <NUM>, <NUM> previously described, the implantable interbody device <NUM>' may include a porous lattice or mesh component <NUM> "within the solid scaffold structure <NUM>' of the device <NUM>'. For instance, the implantable device <NUM>' may have a solid structural component <NUM>' within and on which a porous component <NUM>' may be incorporated, as seen in <FIG> and <FIG>, to form a combination and resultant device <NUM>' which provides a porous component <NUM> within a solid structural component <NUM>. Accordingly, the implantable interbody device <NUM>' may incorporate the same principles of a network of pores and solid surfaces as the devices <NUM>, <NUM>, <NUM> above, to create an improved fusion facilitating device <NUM>' for the cervical spine not heretofore seen. Since the porous component is interconnected to the solid component, greater integration is achieved than with conventional textured coatings, titanium spray coatings, or surface roughenings. These additional surface enhancements are considered optional. For instance, the solid surfaces of the device <NUM>' may be further coated or provided with surface features like roughenings or textures. Similar to the devices <NUM>, <NUM>, <NUM> previously described, the solid scaffold structure <NUM>' may be formed with a surface texture, and may therefore provide an outer surface that is textured, such as a roughened texture or one with discrete geometric protrusions, to enhance surface attachment.

Like devices <NUM>, <NUM>, <NUM>, the extensive porous lattice areas <NUM>' that are engineered to extend all the way around the device <NUM>' allow for more interaction with bone than with convention enhancement methods. Such features are possible for metallic, metallic alloy or polymeric devices based on layer-by-layer deposition manufacturing techniques like 3D printing or selective layer melting (SLM) of metal, metal alloy or polymer. And since the entire device <NUM>' may be formed of metal, metal alloy or polymer, no additional visualization markers are necessary for visualization. Because the devices <NUM>' are created in a single process without the need for connecting subcomponents together, one of the key benefits of the devices is that the interface between the porous lattice areas <NUM>' and the upper surface <NUM>', lower surface <NUM>' or sidewalls <NUM>' is seamless and void of mechanical or chemical bonding, adding to the overall strength of the devices <NUM>'. As shown, the body of device <NUM>' incorporates the porous lattice or mesh structures <NUM>' into itself. The porous lattice structure <NUM>' is not a separate panel that is added onto the body, but is integrated into the body of the device <NUM>'.

Unlike implantable device <NUM>, the implantable device <NUM>' of the present embodiment does not include any angular screw holes at its anterior portion, or trailing end <NUM>'. Instead, the implantable device <NUM>' of the present embodiment may include a hole <NUM>' as shown in <FIG>. The hole <NUM>' may be threaded, as shown. The threaded hole <NUM>' may be used for attachment of an inserter tool, or a threaded nut or screw to secure a graft component. The additional thread form enables easy oblique insertion during surgery. In addition, the threaded screw hole <NUM>' allows for a larger graft area in the central opening <NUM>'.

In some embodiments, the walls 420a, b, c may be concave to create a unique C- or I-beam shape when viewed in cross-section, which serves to enhance support of the endplates and reduce risk of subsidence, while also being able to promote a lightweight, lower stiffness structure. This unique C- or I-beam cross-sectional shape of the sidewalls also helps to enhance support of any graft material contained within the central opening <NUM>' or of biologics formed to nest within this donut shaped lumen. The walls 420a, b, c and lumens together may be radiused in such a way to create a self-supporting arch and other geometries to reduce the need for additional supports during the manufacturing process, such as when 3D printing.

In some embodiments, the implantable interbody device <NUM>' may have non-parallel upper and lower surfaces <NUM>', <NUM>' to form a wedge-shaped body. However, one skilled in the art will appreciate that the implantable interbody device <NUM> may also be provided with parallel upper and lower surfaces <NUM>', <NUM>'. The implantable interbody device <NUM>' may have any suitable shape or size to allow it to be used under lordotic or kyphotic conditions, similar to devices <NUM>, <NUM>, <NUM> above.

Similar to device <NUM>, the device <NUM>' may have an indicator nose through hole <NUM>'. The indicator nose through hole <NUM>' may be configured for detection and may be used as a visual aid, such as an x-ray indicator. In addition, as shown in <FIG>, additional visual aids such as x-ray indicators may be present <NUM>' in the device <NUM> to assist with the navigation and orientation of the device <NUM> during implantation. According to other aspects of the disclosure, the device <NUM>' may include a center located "I" marker for visibility, which can be seen through the porous lattice or mesh structure <NUM>, similar to the "I" beam <NUM> of device <NUM> which may also serve as an x-ray marker. Further, the unique hybrid scaffold structure of the device <NUM> enables better graft retention with its concavity. The textured exterior surface enhances bone attachment and bone fusion. As with devices <NUM>, <NUM>, <NUM> the device <NUM>' may further include additional surface enhancements such as coatings, surface textures or surface roughenings.

It will also be appreciated that the angular positioning of the various holes, as described above, allows the present device <NUM>' to be of a relatively small size and therefore insertable from an oblique angular approach into the intervertebral spaces of the spine. Thus, it will be appreciated that the angular positioning of the holes can assist effective operation of the device <NUM> and the ability to "stack" implants in adjacent multilevel procedures without the securing means interfering with each other. Such a feature can be of major significance in some situations and applications.

Claim 1:
An implantable device (<NUM>, <NUM>', <NUM>, <NUM>') comprising:
a generally trapezoidal shaped body configured for midline insertion between vertebral bodies of a spine, the body having an upper surface (<NUM>, <NUM>', <NUM>, <NUM>'), a lower surface (<NUM>, <NUM>', <NUM>, <NUM>'), an anterior portion (<NUM>, <NUM>', <NUM>, <NUM>'), a posterior portion (<NUM>, <NUM>', <NUM>, <NUM>'), the body comprising a solid scaffold structure (<NUM>, <NUM>', <NUM>, <NUM>') and characterized in that a pair of sidewalls (<NUM>, <NUM>', <NUM>, <NUM>') extend between the upper and lower surfaces and connect the posterior and anterior portions, and
at least one of the upper surface, lower surface or sidewalls further has a porous structure (<NUM>, <NUM>', <NUM>, <NUM>') integrated into the body, the porous structure having a repeating geometric unit of cells, the porous structure further being configured to allow bony ongrowth and bony ingrowth therethrough.