Patent Description:
The present invention relates to spinal surgery, namely, the fusion of adjacent intervertebral bodies or the replacement of a vertebral body.

Back pain can be caused by many different maladies, not the least of which are problems that directly impact the intervertebral discs of the spine. Typical disc issues include, inter alia, degeneration, bulging, herniation, thinning and abnormal movement. One method of treatment of such disc problems that has been widely utilized in the field of spinal surgery is a spinal fusion procedure, whereby an affected disc is removed, and the adjacent vertebral bodies are fused together through the use of interbody spacers, implants or the like. In some instances, it may also be necessary to remove and replace an entire vertebral body. This is often accomplished through the use of a larger implant that acts to fuse together the vertebral bodies adjacent the removed vertebral body.

The aforementioned implants often rely upon mechanical features to ensure engagement between the devices and the bone of the existing vertebral bodies. This coupled with the normal compressive load of the spine acts to keep the implant in place until bone can grow from the existing vertebral bodies into and through the implant. To encourage the bone growth, the implants are often pre-loaded with bone growth promoting material and thereafter placed into the spine. Bone growth promoting material may include naturally occurring bone, artificial materials or the like.

This pre-loading of bone growth promoting material normally takes place prior to implantation of existing implants, typically on a back table of the operating room. This requires the surgeon or other medical professional to estimate the overall amount of material to be pre-loaded into the implant, which is often not an easy task. Moreover, the pre-loaded material can fall out of the implant during the implantation process. All of this has the tendency to create an inefficient surgical procedure. <CIT> and <CIT> show examples of spinal implant devices that allow for in situ application of substances such as bone growth material.

Therefore, there exists a need for an improved spinal implant that overcomes the aforementioned drawbacks.

The present invention relates to a spinal implant device as claimed hereafter. Preferred embodiments of the invention are set forth in the dependent claims.

The present application discloses several embodiment spinal implants that allow for in situ application of a material such as cement, a bone growth promoting substance, BMA, biologics, antimicrobials, antibiotics, or the like. The implants in accordance with the present application provide a more efficient manner of providing such substances to the intervertebral space. Although implants in accordance with the present application may widely vary from what is specifically disclosed herein, the implants generally include a passage fluidly connected to holes either on one or all of the upper and lower surfaces and interior surface of a cavity formed through the implant. The holes may be sized and/or shaped to allow for uniform flow of material introduced into the implant. While largely disclosed as an implant suitable for fusing adjacent vertebral bodies, implants in accordance with the present application may be suited for replacement of a vertebral body. Likewise, although largely shown as being suitable for introduction into the body of a patient from a certain aspect, implants according to the present application may be configured for introduction from any aspect.

A first aspect of the present application is a spinal implant having an upper surface including a first hole, a lower surface including a second hole a cavity formed through the upper and lower surfaces, the cavity including a third hole and a fitting including a passage in fluid communication with the first, second and third holes.

Other embodiments of the first aspect may vary from the foregoing. For instance, the spinal implant may further include a plurality of first, second and third holes, a manifold in fluid communication with the passage, a first channel in fluid communication with the manifold and the first holes and a second channel in fluid communication with the manifold and the second holes. The first and second channels may be curved, as may the manifold be curved. The first holes, second holes, first channel and second channel may increase in size as they extend further away from the passage. The third holes may be in fluid communication with the manifold and at least one of the first and second channels. The implants may further have a porous structure at the upper and/or lower surfaces. In certain embodiments, the fitting may be a male luer fitting. An insertion tool may be engaged with the fitting. The spinal implants of the first aspect may be designed to be implanted from various aspects of a patient, including from an anterior aspect of a patient. The passage, the manifold, the first channel, the second channel and the first and second holes may be included in a fluid transfer structure. That structure may be formed separately from a remainder of the implant. The implant may further include sidewalls with windows formed therethrough, the windows in fluid communication with the cavity. A fourth hole and a fifth hole may be located within the windows and in fluid communication with the passage.

A second aspect of the present application is another spinal implant having an upper surface including a plurality of first holes, a lower surface including a plurality of second holes, a cavity formed through the upper and lower surfaces and a fitting including a passage in fluid communication with the first and second holes.

Other embodiments according to the second aspect may include a manifold in fluid communication with the passage, a first channel in fluid communication with the manifold and the first holes and a second channel in fluid communication with the manifold and the second holes. A plurality of third holes may be in fluid communication with the cavity.

A third aspect of the present application is yet another spinal implant having an upper surface, a lower surface, a cavity formed through the upper and lower surfaces, the cavity including a plurality of holes and a fitting including a passage in fluid communication with the holes.

In another embodiment according to the third aspect, the upper surface may include a plurality of second holes and the lower surface may include a plurality of third holes.

A more complete appreciation of the subject matter of the present application and of the various advantages thereof can be realized by reference to the following detailed description in which reference is made to the accompanying drawings in which:.

An implant <NUM> according to a first embodiment of the present application is depicted in <FIG>. Implant <NUM> is shown as an implant suitable for implantation from an anterior aspect of a patient. However, as will be readily apparent from the below discussion pertaining to other embodiments, the present application is not limited to any particular type of implant design. Rather, it is contemplated that certain features of the present application can be implemented in different types of implants. For instance, implants according to the present application can be adapted for implantation from posterior, lateral, posterior-lateral aspects or the like of the patient. Moreover, implants according to the present application may be constructed of different types of materials that are both biocompatible and suitable to withstand the natural forces of the human spine. For instance, it is contemplated that implants according to the present application may be constructed of metallic materials such as titanium, polymeric materials such as PEEK or the like.

Implant <NUM> is shown including upper and lower surfaces <NUM> and <NUM>, respectively. Each surface includes a plurality of holes <NUM> formed therethrough, although the overall number of holes and their shape may vary depending upon the particular implant and its overall size. Implant <NUM> also includes a central cavity <NUM> formed through a central portion of the implant and through each of surfaces <NUM> and <NUM>. Cavity <NUM> can be sized and shaped differently from what is shown and can be located in other locations of implant <NUM>. The interior of cavity <NUM> also includes a plurality of holes <NUM>, which like holes <NUM> may vary in overall number and shape. It is also contemplated to include more than one cavity through the upper and lower surfaces of the implant.

Implant <NUM> also includes a luer fitting <NUM> formed in a front portion thereof. In other embodiments, a different type of fitting may be utilized (e.g., threaded, snap-fit, etc.. Fitting <NUM> is designed to be engaged by a similarly designed insertion tool (discussed below) and includes a passage <NUM>. As shown in <FIG>, passage <NUM> leads to a manifold <NUM> fluidly connected with holes <NUM> and <NUM>. In particular, as is shown in <FIG> and <FIG>, manifold <NUM> is connected to holes <NUM> and <NUM> through a series of internal passages (a single flow channel <NUM> is shown in <FIG>, while two channels <NUM> and <NUM> are shown in <FIG>), so that material introduced through passage <NUM> can ultimately pass through holes <NUM> and <NUM>. It is to be understood that manifold <NUM> actually connects with the two flow channels <NUM>, <NUM>, such that channel <NUM> is in fluid communication with holes <NUM> on upper surface <NUM> and channel <NUM> is in fluid communication with holes <NUM> on lower surface <NUM>. The channels are also in fluid communication with holes <NUM> on the interior of cavity <NUM>. This allows for bone growth promoting material, cement or the like to be introduced after implantation of implant <NUM>, which in turn allows for both an easier implantation procedure and better application of the material to the surgical site.

<FIG> depict a second embodiment implant <NUM>. Because of the similarities of implant <NUM> to above-discussed implant <NUM>, like reference numerals will be utilized to describe like elements, albeit within the <NUM>-series of numbers. For instance, implant <NUM> includes an upper surface <NUM>, a lower surface <NUM>, a cavity <NUM>, openings <NUM>, a fitting <NUM> and a passage <NUM>. The major difference between implants <NUM> and <NUM> is that the latter does not include any holes through its upper and lower surfaces <NUM>, <NUM>. Thus, any material introduced through passage <NUM> only extends into cavity <NUM>. This type of design results in an implanted implant more akin to traditional spinal implants, i.e., one in which grafting material or the like is only included in a central cavity or the like. Like implant <NUM>, implant <NUM> includes a manifold <NUM> and flow channels <NUM>, <NUM>. Also like implant <NUM>, implant <NUM> is designed to be implanted from an anterior aspect of a patient. Of course, implant <NUM>, like all embodiment implants disclosed in the present application, could be configured for implantation from other aspects, as well as could exhibit different overall shapes and/or sizes and in its individual features.

<FIG> depict yet another embodiment implant <NUM>. As with implant <NUM>, like elements included in implant <NUM> will be identified with like reference numerals within the <NUM>-series of numbers. Contrary to implant <NUM>, implant <NUM> only includes holes <NUM> through upper and lower surfaces <NUM>, <NUM>. There are no holes included within cavity <NUM>. Therefore, material introduced through passage <NUM> only extends to those upper and lower surfaces. Implant <NUM> is best suited for situations in which the implant is to be cemented in place between vertebral bodies. Cement injected through passage <NUM> extends to the interface between upper and lower surfaces <NUM>, <NUM> and the vertebrae. Cavity <NUM> could separately be packed with bone growth promoting materials or the like, but such is up to the surgeon. It is also contemplated to provide an implant <NUM> without a cavity <NUM>. Such an embodiment could include additional holes <NUM> on its upper and lower surfaces <NUM>, <NUM>.

<FIG> depict yet another embodiment implant <NUM>, which is closest in design to implant <NUM>. Implant <NUM> only includes holes <NUM> formed through its upper and lower surfaces <NUM>, <NUM>, with none being formed in cavity <NUM>. However, holes <NUM>, as well as flow channel <NUM> exhibit varying sizes. More specifically, holes <NUM> and flow channel <NUM> increase in size as they progress from passage <NUM>. This increase in size is aimed at ensuring balanced fluid flow. In other words, the design is such that each of holes <NUM> get the same amount of fluid flow of material, thus ensuring even distribution of cement or other materials introduced through passage <NUM>. Of course, the same concept may be employed in implants like above discussed implants <NUM>, <NUM>, where holes also extend into the central cavities of the implants.

<FIG> depict a PLIF-style (i.e., best suited for implantation from a posterior lateral aspect of a patient) implant <NUM> in accordance with the present application. This is one example of how the overall implant design can vary from those anterior implants that are described above. Aside from the overall difference in shape, implant <NUM> includes an internally threaded passage <NUM> in lieu of a luer fitting or the like. Otherwise, implant <NUM> provides the similar functionality to that of above-discussed implant <NUM>. Of course, any of the aforementioned variations could be applied to implant <NUM>. For instance, cavity <NUM> could include holes in fluid communication with passage <NUM>.

The use (not forming part of the claimed invention) of implants according to the present application is depicted in <FIG> For ease of describing the method of use, implant <NUM> will be referred to. However, it is contemplated that any of the above-described implants, or variations thereof, could be utilized in such use. As shown in <FIG> implant <NUM> is first connected with an insertion tool <NUM>. The latter is designed so as to rigidly engage implant <NUM>, including, for instance, a female luer fitting <NUM> (best shown in <FIG>). Tool <NUM> also includes an internal passage <NUM> for allowing material to be introduced through passage <NUM> of implant <NUM> when the tool is connected thereto. Although tool <NUM> is depicted as including a threaded end opposite to fitting <NUM>, many different configurations are contemplated. Essentially, tool <NUM> must be connected, either removably or integral with a source of material. Many different designs for such connection are contemplated, as are the sources that provide the material. For instance, it is contemplated to provide a source of material that is pressurized or capable of being pressurized to allow deployment through passage <NUM>.

With implant <NUM> connected to tool <NUM>, the latter may be manipulated to place the former between vertebral bodies, as is shown in <FIG>. Although the vertebral bodies shown are naturally adjacent to one another, it is contemplated that implant <NUM> may be sized and shaped to be placed between vertebral bodies that have become adjacent by virtue of the removal of another vertebral body. Once implant <NUM> is placed, material may be introduced through passage <NUM> of tool <NUM> and into implant <NUM>. The above-discussed passage <NUM>, channels <NUM>, <NUM> and holes <NUM>, <NUM> of implant <NUM> allow for such material to ultimately extend through upper and lower surfaces <NUM>, <NUM> and/or into cavity <NUM>. <FIG>, for instance, depict an implant according to the present application which has been implanted between two artificial bodies. Cement was thereafter introduced and is shown extending through upper and lower surfaces of the implant and into the artificial bodies. This depicts a scenario where an implant like above-discussed implant <NUM> is initially fixed in place through the use of cement. Finally, <FIG> depicts removal of tool <NUM> from implant <NUM>.

<FIG> depict 3D printed versions of implant <NUM> and implant <NUM>, respectively. As shown, these versions of the implants include porous upper and lower surfaces, as can be created through the use of a 3D printing process such as is disclosed in <CIT> and <CIT>; <CIT>, <CIT>, <CIT>; and <CIT> and <CIT>.

The solid portions of the implants can also be formed through the use of similar procedures. It is to be understood that creating implants according to the present application via a 3D printing may require that the design be modified to allow for such a process. For instance, it is difficult, if not impossible, to create a surface directly over a void when using a 3D printing process. Therefore, the various manifolds, channels and passages may be curved or radiused to permit creation via the 3D printing process. It is also contemplated to form any porous region via any other suitable process, for example, a laser etching procedure.

<FIG> depicts an implant <NUM> similar to above-discussed implant <NUM>, while <FIG> depict implants <NUM> and <NUM> similar to above-discussed implant <NUM>. As such, like reference numerals are utilized in such figures, where applicable. The implants of <FIG> differ from the above-discussed implants in that they include lateral windows <NUM>, <NUM> and <NUM>, respectively, on each side of the implant. In each case, the lateral windows may allow for material introduced into the window to leach out and into the disc space. The windows may also act to reduce the overall stiffness of implants <NUM>, <NUM> and <NUM> and to improve views during an imaging process (e.g., fluoroscopy). In this regard, it is contemplated that the windows may be tapered in a similar manner to the lordotic taper of the implant, where applicable. Furthermore, in the case of implant <NUM>, lateral window <NUM> includes holes <NUM>. These holes, like the others discussed above, allow for material introduced into the implant to pass therethrough.

<FIG> depict yet another embodiment implant <NUM> similar to above-discussed implant <NUM>. Most notably, implant <NUM> only includes holes <NUM> on an interior of cavity <NUM>. Implant <NUM> also includes porous upper and lower surfaces <NUM>, <NUM>. The partial transparent view of <FIG> shows the inner components (e.g., manifold <NUM> and channels <NUM>, <NUM>), while the partial transparent implantation view of <FIG> shows the flow of material into cavity <NUM> and hence the disc space. It is noted that <FIG> does not include reference numerals so that the fluid flow can be fully appreciated.

<FIG> depict an implant <NUM> similar to above-discussed implant <NUM>. Implant <NUM> includes porous upper and lower surfaces <NUM>, <NUM>, as well as lateral windows <NUM> with holes <NUM>. The partial transparent implantation view of <FIG> depicts the flow of material to upper surface <NUM>, as well as from window <NUM>. It is noted that <FIG> does not include reference numerals so that the fluid flow can be fully appreciated.

Implant <NUM> of <FIG> and <FIG> exhibits an overall design similar to that disclosed in <CIT> ("the '<NUM> Patent").

In addition to employing a stand-alone design similar to that of the '<NUM> Patent, implant <NUM>, like those discussed above, includes a passage <NUM> designed to fluidly engage an insertion tool. This allows for material to be introduced into implant <NUM> where it is ultimately dispersed within cavity <NUM>. The flow of such material is shown in the partial transparent implantation view of <FIG>.

<FIG> depict an embodiment implant <NUM>, which is particularly suited for creation via a 3D printing or additive manufacturing process. In particular, in addition to including many similar elements to those discussed above in connection with the foregoing embodiments, implant <NUM> includes a preformed fluid transfer structure <NUM> (shown alone in <FIG>) that includes channels and holes formed therein. This component can be created separately from the remainder of implant <NUM> and the can be built upon utilizing a 3D printing process or the like (see the partial hidden view of <FIG>). Additionally, the implant <NUM> and the preformed fluid transfer structure <NUM> can be created simultaneously. Alternatively, fluid transfer structure <NUM> could be formed via a similar process. Implant <NUM> exhibits a remaining structure similar to that disclosed in <CIT>, and the related utility application filed on the same date as the present application.

For instance, the implant can exhibit exterior surfaces that include both porous and non-porous sections.

<FIG> depicts a cross-sectional view of yet another embodiment implant <NUM>. As shown, passages <NUM> are simply formed as triangular shaped voids within the overall structure of the implant. It is noted that these passages may be in communication with holes (not shown) like those discussed above, or could simply allow for material to leach or push through the porous material making up implant <NUM>. In certain embodiments, this leaching may occur only at certain locations. Implant <NUM> is yet another implant embodiment created utilizing a 3D printing process, but could of course be formed through the use of other known manufacturing processes.

The various embodiment implants disclosed in the present application make it readily apparent that implants according to the present application may vary widely while still encompassing the salient features of the application. It is to be understood that not all contemplated embodiments have been shown. It is also to be understood that the various embodiments may borrow certain features from each while still remaining within the scope of the present application. It is also to be understood that although it is specifically discussed herein to create implants according to the present application via a 3D printing like process, other processes may be utilized to manufacture the implants of the present application.

Although shown as distinct passages, manifolds, channels and holes, it is contemplated to provide different formations for allowing for material to be introduced into implants according to the present application and to be dispersed therefrom. For instance, it is contemplated to provide chambers that are in fluid communication with porous areas of the implant so that material within the chambers is allowed to pass through the porous material. The ability to include porous material in the implants themselves may negate the need for a specific passage/manifold/channel system. Moreover, it is contemplated to include independent passage/manifold/channel systems within a single implant. This, in connection with a multi-bore insertion tool may allow for the introduction of more than one material into the implant. For instance, it may be beneficial to have one material (e.g., allograft) directed to the cavity of the implant, while another material (e.g., cement) is directed to the upper and lower surfaces. It is also contemplated to provide holes on an exterior surface of the various implants, so as to allow material to be directed from the implant. This allows for such material to be dispersed around the implant, which may be beneficial in a fusion procedure. Of course, porous areas can also be included on the exterior of the implant to allow for same.

Claim 1:
A spinal implant comprising:
a preformed fluid transfer structure having at least a first channel in fluid communication with a fitting, the first channel forming a pathway around a cavity, the first channel including at least one hole, and
a porous and non-porous structure around at least a portion of the preformed fluid transfer structure such that the cavity is defined by an inner wall of the porous structure, the porous and non-porous structure enclosing the at least one hole,
wherein an opening of the fitting is exposed on an outer wall of the porous and non-porous structure such that the opening is in fluid communication with the hole through the first channel.