Porous fusion device

Abstract

A porous fusion device is configured to assist in fusing two or more biological tissues. The porous fusion device includes an outer frame, an outer lattice cage within the outer frame, an inner porous lattice structure, and a material injection port disposed at the outer frame and protruding into the inner porous lattice structure. The internal porous lattice structure may be characterized by a variable density gradient that mimics biological tissue and allows the material to be dispersed therethrough.

Description

[0001] Cross Reference to Related Applications

[0002] This non-provisional patent application claims priority benefit under all common subject matter of U.S. Provisional Patent Application No. 63 / 528,197, filed on July 21, 2023, and entitled “POROUS FUSION DEVICE.” The above-identified application is hereby incorporated by reference in its entirety. TECHNICAL FIELD

[0003] Embodiments of the present invention relate to a fusion device for use with biological tissue. More specifically, embodiments of the present invention relate to a porous fusion device comprising an internal lattice structure. BACKGROUND

[0004] Conventional fusion devices do not allow the fusion material to propagate throughout the fusion device, including the interior regions. This can slow the growth of the biological tissue and generally reduce the efficacy of the fusion device. Additionally, conventional fusion devices lack structural features that mimic the biological tissue (e.g., bone) that it is fusing. As a result, the fusion device can behave differently than the tissue being fused as the biological growth occurs. This can cause the tissue to separate from the fusion device and prevent growth and / or fusion from occurring. SUMMARY

[0005] Embodiments of the present invention address the above issues by providing a porous fusion device and methods of operating the same. By providing a porous fusion device, the material (e.g., bone graft material) that is assisting in fusing two or more tissues can flow to the internal structure of the porous fusion device, thereby increasing the effectiveness of the tissue fusion. Furthermore, the density of the porous structure within certain regions of the porous fusion device can be adjusted. These structural adjustments allow the porous fusion device to better mimic the tissue structure of the two or more tissues being fused.

[0006] In some embodiments, the technology described herein relates to a porous fusion device comprising: an outer frame; an outer lattice cage disposed within the outer frame; an internal porous lattice structure disposed within the outer lattice cage; and a material injection port disposed at the outer lattice cage and protruding into the internal porous lattice structure.

[0007] In some embodiments, the technology described herein relates to a porous fusion device, wherein the material injection port comprises a threaded channel comprising a first threaded portion and a second threaded portion having a horizontal break therebetween, and wherein the material injection port is configured to interface with an injection tool.

[0008] In some embodiments, the technology described herein relates to a porous fusion device, wherein the horizontal break is configured to disperse an applied force.

[0009] In some embodiments, the technology described herein relates to a porous fusion device, wherein the internal porous lattice structure comprises a variable density from an outer lattice cage of the porous fusion device to a most central point.

[0010] In some embodiments, the technology described herein relates to a porous fusion device, wherein the variable density comprises a gradual decrease in density from an outer lattice cage of the porous fusion device to a most central point.

[0011] In some embodiments, the technology described herein relates to a porous fusion device, wherein the outer lattice cage comprises one or more of an octagonal lattice, a heptagonal lattice, a hexagonal lattice, or a pentagonal lattice.

[0012] In some embodiments, the technology described herein relates to a porous fusion device, further comprising a plurality of material propagation channels disposed through the internal porous lattice structure and the outer lattice cage.

[0013] In some embodiments, the technology described herein relates to a porous fusion device, further comprising a stopper disposed opposite the material injection port, the stopper configured to retain the injected material within the porous fusion device.

[0014] In some embodiments, the technology described herein relates to a porous fusion device for fusing two or more tissues, comprising: an outer frame; an outer lattice cage disposed within the outer frame; an internal porous lattice structure disposed within the outer lattice cage; a material injection port disposed at the outer lattice cage and projecting into the internal porous lattice structure; and a plurality of material propagation channels disposed within the internal porous lattice structure and extending to the outer lattice cage, wherein the internal porous lattice structure is organized by a variable density from an outer lattice cage of the porous fusion device to a most central point, wherein the porous fusion device is configured to be backfilled with material after insertion into a patient.

[0015] In some embodiments, the technology described herein relates to a porous fusion device, wherein the plurality of material propagation channels comprises at least one horizontal material propagation channel fluidly coupled to at least one vertical material propagation channel.

[0016] In some embodiments, the technology described herein relates to a porous fusion device, wherein the at least one vertical material propagation channel extends through the outer frame.

[0017] In some embodiments, the technology described herein relates to a porous fusion device, wherein the material injection port further comprises a threaded channel having a first threaded portion and a second threaded portion disposed with a break therebetween.

[0018] In some embodiments, the technology described herein relates to a porous fusion device in which a plurality of material propagation channels include at least one horizontal material propagation channel fluidly coupled to at least one radially extending material propagation channel.

[0019] In some embodiments, the technology described herein relates to a porous fusion device in which a plurality of material propagation channels are arranged to guide material toward two or more tissues.

[0020] In some embodiments, the technology described herein relates to a method of instructing the use of a porous fusion device, comprising: providing a porous fusion device comprising: an outer frame; an outer lattice cage disposed within the outer frame; an inner porous lattice structure disposed within the outer lattice cage; and a material injection port disposed at the outer lattice cage and protruding into the inner porous lattice structure; instructing the attachment of a material injection tool to the material injection port of the porous fusion device; instructing the insertion of the porous fusion device between at least two biological tissues; instructing the filling of at least a portion of the porous fusion device with material via the material injection tool; and instructing the disconnection of the material injection tool from the material injection port on the porous fusion device.

[0021] In some embodiments, the technology described herein relates to a method in which the material injection port of a porous fusion device further includes a threaded channel comprising a first threaded portion and a second threaded portion therebetween disposed therebetween.

[0022] In some embodiments, the techniques described herein relate to a method in which instructing the filling of a porous fusion device with material occurs at least partially prior to instructing the insertion of the porous fusion device between at least two biological tissues.

[0023] In some embodiments, the techniques described herein relate to a method in which the material injected into the porous fusion device is a bone graft material.

[0024] In some embodiments, the techniques described herein relate to a method in which the internal porous lattice structure of a porous fusion device is organized by a variable density from the outer lattice cages of the porous fusion device to the central point of the porous fusion device.

[0025] In some embodiments, the technology described herein relates to a method in which a porous fusion apparatus further includes a stop disposed opposite a material injection port and configured to retain material injected into the porous fusion apparatus.

[0026] This summary is provided to introduce, in a simplified form, a series of concepts further described in the detailed embodiments described below. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter. Other aspects and advantages of the invention will become apparent from the following detailed description of embodiments and the accompanying drawings. Attached Figure Description

[0027] The embodiments of the present invention are described in detail below with reference to the accompanying drawings, wherein:

[0028] Figure 1 A porous fusion apparatus is illustrated in some embodiments;

[0029] Figure 2 A rear view of a porous fusion device in some embodiments is illustrated;

[0030] Figure 3 A cross-sectional view of a porous fusion device in some embodiments is shown;

[0031] Figure 4A An exemplary embodiment of a variable density progression in a first direction is illustrated.

[0032] Figure 4B An exemplary embodiment of a variable density gradient in the second direction is illustrated;

[0033] Figure 4C An exemplary embodiment of a variable density gradient in a first direction and a second direction is illustrated;

[0034] Figure 4D A cross-sectional view of a porous fusion device with a variable-density gradient structure is shown.

[0035] Figure 5 A flowchart is provided to illustrate an exemplary method for indicating the use of a porous fusion apparatus.

[0036] The accompanying drawings are not intended to limit the invention to the specific embodiments disclosed and described herein. The drawings are not necessarily drawn to scale, but rather to clearly illustrate the principles of the invention. Detailed Implementation

[0037] The subject matter of the invention is described in detail below to satisfy legal requirements; however, the description itself is not intended to limit the scope of the claims. Rather, the claimed subject matter may be implemented in other ways, in conjunction with other existing or future techniques, to include different steps or combinations of steps similar to those described herein. Minor variations from the description below will be appreciated by those skilled in the art and are intended to fall within the scope of the claimed invention. The terminology should not be construed as implying any particular order of the described steps unless the order of the individual steps is explicitly described.

[0038] The following detailed description refers to the accompanying drawings, which illustrate specific embodiments in which the invention may be practiced. The embodiments are intended to describe aspects of the invention in sufficient detail to enable those skilled in the art to practice it. Other embodiments may be utilized, and changes may be made without departing from the scope of the invention. Therefore, the following detailed description should not be considered limiting. The scope of the invention is defined only by the full scope of the appended claims and their equivalents.

[0039] In this specification, references to "an embodiment," "an embodiment," or "an embodiment" mean that one or more features mentioned are included in at least one embodiment of the present technology. In this specification, individual references to "an embodiment," "an embodiment," or "an embodiment" do not necessarily refer to the same embodiment, nor are they mutually exclusive, unless so stated and / or apparent to those skilled in the art from this specification. For example, features, structures, actions, etc., described in one embodiment may also be included in other embodiments, but are not necessarily included therein. Therefore, the present technology may include various combinations and / or integrations of the embodiments described herein.

[0040] First turn Figure 1This illustration shows a porous fusion apparatus 100. In some embodiments, the porous fusion apparatus 100 may include an outer frame 102, an outer lattice cage 104, an inner porous lattice structure 106, a secondary propagation channel 107, a break 108, a material injection port 110, a connection port 112, an upper region 114, a lower region 116, a first horizontal frame 118, and a second horizontal frame 120. In some embodiments, the outer frame 102 provides structural support for tissue fused by the porous fusion apparatus 100. In some embodiments, the outer frame 102 provides structural support for the porous fusion apparatus 100. In some embodiments, the outer frame 102 may include two horizontal frames (e.g., a first horizontal frame 118 and a second horizontal frame 120) spanned by the outer lattice cage 104. Although two horizontal frames are depicted for the outer frame 102, any number of frames in any orientation may be used for the outer frame 102. In some embodiments, the inner porous lattice structure 106 may fill the volume within the outer frame 102.

[0041] In some embodiments, the outer frame 102 may be arranged according to a first plane. Hereinafter, directional terms (e.g., horizontal, vertical, up, down, etc.) may be used to describe certain aspects and / or components of the porous fusion device 100. It should be noted that these terms are for descriptive purposes only, and any aspect and / or component of the porous fusion device 100 may be in any orientation depending on the orientation of the porous fusion device 100 before and after implantation. In some embodiments, the outer frame 102 may include a first horizontal frame 118 associated with the upper region 114 of the porous fusion device 100 and a second horizontal frame 120 associated with the lower region 116 of the porous fusion device 100. In some embodiments, the outer lattice cage 104 extends between the first horizontal frame 118 and the second horizontal frame 120. In some embodiments, the internal porous lattice structure 106 may occupy at least a portion of the space between the upper region 114 and the lower region 116. In some embodiments, the first horizontal frame 118 and the second horizontal frame 120 may be parallel to each other or substantially parallel to each other. In some embodiments, the first horizontal frame 118 and the second horizontal frame 120 may be at any angle other than being parallel to each other.

[0042] In some embodiments, the secondary propagation channel 107 may extend through the internal porous lattice structure 106, and the secondary propagation channel 107 may be partially or completely disposed between the first horizontal frame 118 and the second horizontal frame 120. In some embodiments, the material injection port 110 may be located at the outer frame 102 between the first horizontal frame 118 and the second horizontal frame 120. For example, in some embodiments, the material injection port 110 may be positioned along the outer frame 102 at equidistant points between the first horizontal frame 118 and the second horizontal frame 120. In some embodiments, the break 108 may be oriented substantially parallel to one or both of the first horizontal frame 118 or the second horizontal frame 120. In some embodiments, the horizontal break 108 may be oriented at an angle other than parallel to one or both of the first horizontal frame 118 or the second horizontal frame 120.

[0043] In some embodiments, the material injection port 110 may include an elongated portion (e.g., a rectangular or elliptical shape), as illustrated. In some embodiments, the elongated portion of the material injection port 110 may extend generally parallel to the first horizontal frame 118 and / or the second horizontal frame 120, as illustrated. Alternatively, in some embodiments, the elongated portion of the material injection port 110 may extend at an angle other than parallel to the first horizontal frame 118 and / or the second horizontal frame 120. In embodiments where the material injection port 110 includes an elongated portion, such an arrangement may help disperse applied forces (e.g., torsional forces) exerted on the porous fusion device 100 (e.g., the connection of the insertion device). This force dispersion may prevent damage or other harm to the porous fusion device 100 during the various steps of implanting the porous fusion device 100. In some embodiments, the material injection port 110 may include any other shape, such as circular, square, hexagonal, etc.

[0044] In some embodiments, the outer lattice cage 104 may be an octagonal lattice, a heptagonal lattice, a hexagonal lattice, a pentagonal lattice, a square lattice, or any form of lattice structure. In some embodiments, the outer lattice cage 104 may be a horizontal and vertical grid. In some embodiments, the outer lattice cage 104 may be a diagonal grid. In some embodiments, the outer lattice cage 104 may cover the sides of the porous fusion device 100. In some embodiments, the outer lattice cage 104 may not cover some or all of the lower region 116 of the porous fusion device 100.

[0045] In some embodiments, the material injection port 110 is incorporated into the outer frame 102. In some embodiments, the material injection port 110 may protrude through the outer lattice cage 104 and into the inner porous lattice structure 106. In some embodiments, the material injection port 110 includes a connection port 112. In some embodiments, the connection port 112 may be configured to interface with a plurality of tools, such as bolts, material injection tools, mounting devices, insertion and / or removal tools, mechanical attachments, drills, threaded inserts, or any other compatible tools. The material injection port 110 may further include a break 108. Similar to the shape of the material injection port 110 described above, in some embodiments, the break 108 may prevent damage (e.g., torsional damage) to the porous fusion device 100 during insertion with any of the aforementioned tools. In some embodiments, the break 108 may be configured to prevent damage to the porous fusion device 100 by reducing the stiffness of the connection port 112. In some embodiments, the break 108 may separate the connection port 112 into a first threaded portion 112a and a second threaded portion 112b.

[0046] In some embodiments, the connection port 112 may be unthreaded and instead include a mechanical fastener for attaching to the injection tool. In some embodiments, the mechanical fastener is a rivet, clamp, latch, tapered anchor, expansion anchor, or any other form of mechanical fastener. In some embodiments, an adhesive is used to attach the injection tool to the porous fusion device 100. In some embodiments, the adhesive may be a hot melt adhesive, a biocompatible adhesive, a bioconsumable adhesive, any combination of these adhesives, or any other form of adhesive.

[0047] In some embodiments, the porous fusion device 100 includes a secondary propagation channel 107 disposed through or substantially through the outer lattice cage 104 and the inner porous lattice structure 106. In some embodiments, the secondary propagation channel 107 facilitates the propagation of material throughout the porous fusion device 100. In some embodiments, the secondary propagation channel 107 provides a pathway for the growth of biological structures. In some embodiments, the porous fusion device 100 may further include at least one primary propagation channel (e.g., as shown in the image). Figure 3 The primary propagation channel 140 depicted is configured to fluidly couple the material injection port 110 and the secondary propagation channel 107 to allow material to propagate toward the secondary propagation channel 107.

[0048] In some embodiments, the outer frame 102 includes structural supports (not shown) extending from the upper region 114 of the porous fusion device 100 to the lower region 116 of the porous fusion device 100. For example, a structure having a higher density than the outer lattice cage 104 may span the vertical length of the porous fusion device 100 to improve the structural integrity of the porous fusion device 100 under compressive forces. In some embodiments, the outer lattice cage 104 may be incorporated into the structural supports and span any gaps therebetween. In some embodiments, the structural supports are temporary and dissolve or otherwise decompose after implantation of the porous fusion device 100.

[0049] In some embodiments, the internal porous lattice structure 106 and the external lattice cage 104 can be configured to simulate bone material. (See below for more information.) Figures 4A to 4D As described, in some embodiments, the internal porous lattice structure 106 may be configured to have a stronger exterior and a weaker interior structure. In some embodiments, the internal porous lattice structure 106 may be configured to mimic bone material, such that the internal porous lattice structure 106 may have a higher density exterior that transitions to a lower density interior. In some embodiments, the outer lattice cage 104 may be configured to have a higher density than the internal porous lattice structure 106, such that the porous fusion device 100 mimics bone material by providing a higher density and strength exterior and a lower density and strength interior.

[0050] exist Figure 2 The image depicts an exemplary rear view of a porous fusion apparatus 100. In some embodiments, the porous fusion apparatus 100 includes a stop 130 that may be incorporated into an outer lattice cage 104. In some embodiments, the stop 130 includes a first stop 132, a second stop 134, and a crossing channel 136 therebetween. In some embodiments, the stop 130 extends a distance from one or both of a first horizontal frame 118 or a second horizontal frame 120. For example, as depicted, the first stop 132 extends a distance away from the first horizontal frame 118, and the second stop 134 extends a distance away from the second horizontal frame 120. In some embodiments, the stop 130 is configured to redirect the propagation of material injected into the porous fusion apparatus 100. For example, the stop 130 may redirect injected material back toward the interior of the porous fusion apparatus 100 (e.g., within the internal porous lattice structure 106). In some embodiments, the stop 130 provides additional structural support to the porous fusion apparatus 100. In some embodiments, the stop 130 further includes a crossing channel 136. As illustrated, an outer lattice cage 104 may extend through the crossing channel 136. In some embodiments, the crossing channel 136 may coincide with the first stop 132 and the second stop 134 to form an integral stop including the first stop 132, the second stop 134, and the crossing channel 136.

[0051] In some embodiments, the crossing channel 136 may be configured to absorb compressive forces applied to the porous fusion device 100. For example, in an embodiment utilizing the porous fusion device 100 as a vertebral fusion device, two adjacent vertebrae will exert compressive forces on the porous fusion device 100 at the upper region 114 and the lower region 116. Therefore, if these compressive forces exceed a threshold, the crossing channel 136 can provide a flexible absorption zone that is less rigid than the surrounding portions of the porous fusion device 100 (e.g., the upper region 114 and the lower region 116). Because the crossing channel 136 includes a less rigid structure, it can be slightly or completely compressed during the application of compressive forces. In some embodiments, the crossing channel 136 may be configured to return to its initial structural formation after the compressive forces have been relieved. In this way, the crossing channel 136 allows the porous fusion device 100 to more closely mimic the modulus of bone compared to a completely rigid fusion device. In some embodiments, the crossing channel 136 may alternatively include a rigid structure that resists compressive forces applied by the crossing bone structure (e.g., two adjacent vertebrae).

[0052] In some embodiments, the stop 130 may partially or completely enclose the outer lattice cage 104. For example, the stop 130 may replace or otherwise cover the entire outer lattice cage 104, thereby completely enclosing the porous fusion device 100. In some embodiments, the stop 130 may be configured to prevent injected material (e.g., bone graft material) from leaving the porous fusion device 100. In some embodiments, the stop 130 may cover the vertical portion of the outer lattice cage 104 but not the non-vertical portion. For example, in some embodiments, the stop 130 may not cover the upper region 114 or the lower region 116 of the porous fusion device 100, thereby allowing material to propagate from the porous fusion device 100 through the upper region 114 and / or the lower region 116 toward adjacent bone.

[0053] exist Figure 3 The exemplary embodiment of a porous fusion apparatus 100 is depicted in a cross-sectional side view. The porous fusion apparatus 100 may include a primary propagation channel 140 as mentioned above. The primary propagation channel 140 may be fluidly connected to a secondary propagation channel 107. The primary propagation channel 140 may extend from a material injection port 110 to allow material to propagate through the primary propagation channel 140 toward the secondary propagation channel 107. In some embodiments, the primary propagation channel 140 may be a plurality of propagation channels. In some embodiments, the primary propagation channel 140 and the secondary propagation channel 107 are combined to form a network of propagation channels. In some embodiments, the primary propagation channel 140 may include a low-density lattice structure therein to allow material to propagate through the low-density lattice structure of the primary propagation channel 140 toward the secondary propagation channel 107.

[0054] In some embodiments, at least one main propagation channel 140 may be oriented parallel to the first horizontal frame 118 or the second horizontal frame 120, as per [reference to...]. Figure 1 As described. In some embodiments, at least one secondary propagation channel 107 may be oriented substantially perpendicular to the first horizontal frame 118 or the second horizontal frame 120. In some embodiments, at least one secondary propagation channel 107 may be oriented perpendicular to the first horizontal frame 118 or the second horizontal frame 120. In some embodiments, at least one secondary propagation channel 107 may be oriented perpendicular to at least one primary propagation channel 140.

[0055] In some embodiments, the propagation channel network may be configured to extend into a large portion of the porous fusion apparatus 100. The propagation channel network may be configured to slow the propagation of material as it propagates toward the outer lattice cage 104. For example, a secondary propagation channel 107 may become narrower as it extends outward from the primary propagation channel 140. In some embodiments, the second propagation channel 107 may include a low-density lattice structure therein to slow the outward propagation of material toward the outer lattice cage 104. In some embodiments, the propagation channel network may provide an unobstructed path for material propagation toward the outer lattice cage 104 (e.g., maintaining the same width and / or radius). In some embodiments, the density of the inner porous lattice structure 106 may prevent material flow through it, such that the injected material flows only through the propagation network (e.g., the primary propagation channel 140 and the secondary propagation channel 107). The propagation channel network may be enclosed by the outer lattice cage 104, such that the propagation channel network forms multiple horizontal, vertical, and / or any other orientations for the propagation channels toward the outer lattice cage 104.

[0056] Although the secondary propagation channel 107 is depicted extending generally perpendicularly from the main propagation channel 140, in some embodiments, the secondary propagation channel 107 may extend at a different angle from the main propagation channel 140. For example, in some embodiments, the secondary propagation channel 107 may extend radially from the main propagation channel 140. In some embodiments, the secondary propagation channel 107 may extend parallel to the main propagation channel 140, but with a different orientation toward the outer lattice cage 104. Such directional changes and specificities in material propagation are advantageous for targeted distribution of injected material toward specific regions of biological tissue. For example, a radially oriented secondary propagation channel 107 may distribute more injected material toward the exterior of adjacent bone. Such distribution may aid in the fusion and / or healing of these exterior regions of adjacent bone. In these embodiments, the porous fusion device 100 with a specific orientation of the secondary propagation channel 107 may be selected based on the biological tissue being fused and / or healed. In some embodiments, a material propagation network assists in the propagation of material injected into the material injection port 110 throughout the porous fusion device 100, for example, through the internal porous lattice structure 106.

[0057] In some embodiments, the secondary propagation channel 107 may be fluidly coupled to the primary propagation channel 140. In some embodiments, the connection port 112 may be fluidly coupled to the primary propagation channel 140. In some embodiments, the secondary propagation channel 107, the primary propagation channel 140, and the connection port 112 may be fluidly coupled together to provide a material propagation network within the porous fusion apparatus 100. In some embodiments, the connection port 112 may be fluidly coupled to the secondary propagation channel 107. In some embodiments, the secondary propagation channel 107 may be absent, and the connection port 112 may be fluidly coupled to the primary propagation channel 140. In some embodiments, the primary propagation channel 140 may be absent, and the connection port 112 may be fluidly coupled to the secondary propagation channel 107.

[0058] In some embodiments, a material propagation mesh may be arranged within an internal porous lattice structure 106, such that the material propagation mesh can be positioned between a first horizontal frame 118 and a second horizontal frame 120. In some embodiments, the material propagation mesh may include a combination of at least one main propagation channel 140 and at least one secondary propagation channel 107, such that material can propagate through the porous fusion device 100 in multiple directions (e.g., horizontal and vertical directions). In some embodiments, the material propagation mesh may be positioned through the first horizontal frame 118 and the second horizontal frame 120, such that material propagates against a first tissue and a second tissue in contact with the upper region 114 and the lower region 116, respectively.

[0059] In some embodiments, the two or more tissues to be fused are oriented relative to the first horizontal frame 118 and the second horizontal frame 120. In some embodiments, the upper region 114 and the lower region 116 contact the tissues to be fused according to the first horizontal frame 118 and the second horizontal frame 120, such that material can propagate from the porous fusion apparatus 100 and contact the two or more tissues to be fused.

[0060] Now turning Figure 4A An illustration of a variable density gradient 200 is shown for illustrative purposes. In some embodiments, the internal porous lattice structure 106 may be organized in the manner depicted in the variable density gradient 200. In some embodiments, the density of the internal porous lattice structure 106 is variable throughout the porous fusion apparatus 100. The varying density of the internal porous lattice structure 106 can alter the flow rate of the material passing through it. For the purpose of further explanation, Figure 4A and 4BVariable density gradients 200 and 250 are illustrated respectively. In some embodiments, the variable density gradient 200 varies in density between a high-density region 202 and a low-density region 208. In some embodiments, the variable density gradient 200 varies in density from the high-density region 202 to a central point 204 that defines the center point of the depicted vertical plane 206a. In some embodiments, the high-density region 202 may be an outer lattice cage 104. In some embodiments, the central point 204 may be located within the center of the porous fusion apparatus 100.

[0061] In connection with the variable density gradients 200 and 250, in some embodiments, the structure of the internal porous lattice structure 106 has entropic properties. The porous structure defining the internal porous lattice structure 106 can be random, making the porous structure heterogeneous (e.g., varying in size, shape, etc.). Therefore, the entropic properties defining the porous structure of the internal porous lattice structure 106 can be organized in a way that defines the variable density of the entire internal porous lattice structure 106 (e.g., variable density gradients 200 and 250). Similarly, in some embodiments, the structure of the outer lattice cage 104 has entropic properties similar to those described above.

[0062] exist Figure 4B The illustration shows a variable density gradient 250 for illustrative purposes. In some embodiments, the internal porous lattice structure 106 may be organized in the manner shown by the variable density gradient 250. In some embodiments, the variable density gradient 200 follows a horizontal gradient within the porous fusion apparatus 100 as it moves away from the depicted vertical plane 206a. In some embodiments, the variable density gradient 250 follows a vertical gradient within the porous fusion apparatus 100 as it moves away from the depicted horizontal plane 206b. In some embodiments, the variable density gradient 200 and the variable density gradient 250 follow horizontal and vertical gradients, respectively, within the porous fusion apparatus 100. In some embodiments, the variable density gradient 200 and the variable density gradient 250 are reversible and follow opposite gradients from high density to low density as they move away from the center point 204.

[0063] In some embodiments, the internal porous lattice structure 106 is composed of one or both of variable density gradients 200 and 250. For example, the variable density gradients 200 and 250 may extend radially outward from the central point 204 (e.g., as shown in the image). Figure 4C(As illustrated in the illustration). In such embodiments, the center point 204 may be centrally located within the porous fusion apparatus 100. In some embodiments, the density of the internal porous lattice structure 106 organized by the variable density gradients 200 and 250 may decrease as the internal porous lattice structure 106 approaches the center point 204. In some embodiments, the density of the internal porous lattice structure 106 organized by the variable density gradients 200 and 250 may increase as the internal porous lattice structure 106 approaches the outer lattice cage 104.

[0064] In some embodiments, the density gradient between the low-density region 208 and the high-density region 202 may be characterized by variable density gradients 200 and 250. Although not depicted, in some embodiments, the density gradient between the low-density region 208 and the high-density region 202 may be characterized by the opposite form of the variable density gradients 200 and 250. For example, the density of the internal porous lattice structure 106 may decrease as it transitions away from the center point 204.

[0065] exist Figure 4C The illustration shows an exemplary combination of variable density gradient layer 200 and variable density gradient layer 250. The porous fusion apparatus 100 may include, as described above... Figure 4A and Figure 4B The described multiple regions of varying density. In some embodiments, the high-density region 202 may be disposed near the exterior of the porous fusion device 100. For example, the high-density region 202 may be disposed near the outer lattice cage 104 (e.g., Figure 4D (As depicted in the illustration). The porous fusion device 100 may further include a low-density region, such as a low-density region 208. In some embodiments, the low-density region 208 is disposed near the central point 204. In some embodiments, the lowest density point may be characterized by the central point 204, which can be centrally located within the porous fusion device 100. In some embodiments, the internal porous lattice structure 106 may be organized by a variable-density gradient 200 such that the structure of the internal porous lattice structure 106 transitions from low density to high density as it moves away from the central point 204.

[0066] Although not depicted herein, in some embodiments, the density of the outer lattice cage 104 may vary along one or more of the horizontal, vertical, or radial directions. Such variations in the density of the outer lattice cage 104 may aid in guiding the extrusion of material externally into the porous fusion apparatus 100. Alternatively or additionally, as discussed above, a stop 130 may cover a portion of the outer lattice cage 104 to prevent material from being extruded from the outer lattice cage 104 in certain areas, while allowing material to be extruded in other areas not covered by the stop 130.

[0067] In some embodiments, the internal porous lattice structure 106 may extend radially outward from the central point 204. In such embodiments, the internal porous lattice structure 106 may be characterized by at least one variable density gradient (e.g., variable density gradient 200 and / or variable density gradient 250) that mimics biological tissue and / or allows material to be dispersed therethrough.

[0068] Although the internal porous lattice structure 106 is depicted and discussed as including variable density throughout the porous fusion device 100, in some embodiments the density of the internal porous lattice structure 106 may be substantially similar throughout the porous fusion device 100.

[0069] exist Figure 4D In this embodiment, an embodiment of the porous fusion apparatus 100 is illustrated as being organized with variable density gradients 200 and 250. In some embodiments, a high-density region 202 may be disposed near the outer lattice cage 104. In some embodiments, the central point 204 may be disposed within the connection port 112. In some embodiments, a low-density region 208 may be disposed near the central point 204. In some embodiments, at least a portion of the internal porous lattice structure 106 may be organized with high-density regions 202 and low-density regions 208.

[0070] exist Figure 5 The illustration depicts an exemplary method 500 for instructing the operation of a porous fusion device. At step 502, a biological structure fusion device, such as a porous fusion device, is provided. For example, a porous fusion device 100 may be provided. In some embodiments, the porous fusion device 100 may further include additional features not present in this disclosure.

[0071] At step 504, instructions are provided for inserting an injection tool into the biostructure fusion device via a material injection port. For example, instructions are provided for inserting an injection tool (not depicted) into the porous fusion device 100 via material injection port 110. The injection tool may be configured to interface with a connection port 112. In some embodiments, material may be injected into the porous fusion device 100 using the injection tool during step 502. In some embodiments, the porous fusion device 100 may be pre-filled prior to step 502. The porous fusion device 100 may be temporarily attached to the injection tool, allowing the porous fusion device 100 to be inserted and implanted into a patient.

[0072] At step 506, instructions may be provided for inserting a biological structural fusion device (e.g., a porous fusion device 100) into the patient. In some embodiments, instructions may be provided for inserting the porous fusion device 100 between two or more tissues (e.g., bone), such that the porous fusion device 100 promotes the growth of the two or more tissues in and around the porous fusion device 100. In some embodiments, the porous fusion device 100 may not be inserted between two or more tissues, but may be attached to a single tissue. For example, the porous fusion device 100 may extend a single tissue by promoting tissue growth at and from the attachment site.

[0073] At step 508, instructions may be provided for injecting material (e.g., fluid) into the biostructure fusion device. For example, in some embodiments, instructions are provided for backfilling the porous fusion device 100 via an injection tool. In some embodiments, the material may be bone graft material, a bone-growth-promoting chemical, biofoam, bone marrow, synthetic bone graft material, or any other tissue-growth-promoting material. In some embodiments, the material may have a viscosity higher than that of the bone graft material, such that the material can propagate through the low-density portions of the porous fusion device 100 (e.g., low-density region 208). In some embodiments, the material may have a viscosity lower than that of the bone graft material, such that the material can propagate through the high-density portions of the porous fusion device 100 (e.g., high-density region 202). In some embodiments, the structure of the internal porous lattice structure 106 may correspond to the viscosity of the material to be injected into the porous fusion device 100. For example, a high-viscosity material may be used with a low-density internal porous lattice structure 106. Alternatively, a low-viscosity material may be used with a high-density internal porous lattice structure 106. In some embodiments, a medical professional may be instructed to adjust the viscosity of the material based on the density or variable density of the internal porous lattice structure 106. Alternatively, in some embodiments, the material with the correct viscosity is provided to the medical professional along with a porous fusion device 100 having a corresponding density of the internal porous lattice structure 106.

[0074] As discussed above, material can be injected into the porous fusion device 100 using an injection tool. In some embodiments, step 508 may be optional, as the porous fusion device 100 may be pre-filled with material and provided to a medical professional. In such embodiments, the porous fusion device 100 may be pre-filled with material as part of the manufacturing process and provided to a medical professional.

[0075] At step 510, instructions are provided to disconnect the injection tool from the biostructure fusion device (e.g., porous fusion device 100) and remove the injection tool from the patient. The injection tool may be reinserted after step 510 to add additional material. The additional material may have the same or different composition as the initially injected / placed material. In some embodiments, method 500 includes other steps such as: placing a porous fusion device cap on the porous fusion device 100; inserting a secondary fusion device or other component to fill the cavity defined by the material injection port 110; injecting secondary material into the porous fusion device 100 to induce a chemical reaction that promotes tissue fusion and / or growth; and removing and / or scraping away any amount of tissue from the patient prior to insertion of the porous fusion device 100.

[0076] Without departing from the scope of this invention, the features described above and the features claimed below can be combined in various ways. The following examples illustrate some possible, non-limiting combinations:

[0077] (A1) A porous fusion apparatus comprising: an outer frame; an outer lattice cage disposed within the outer frame; an inner porous lattice structure disposed within the outer lattice cage; and a material injection port disposed at the outer lattice cage and protruding into the inner porous lattice structure.

[0078] (A2) A porous fusion apparatus as represented in (A1), wherein the material injection port includes a threaded channel having a first threaded portion and a second threaded portion having a horizontal break therebetween, and wherein the material injection port is configured to interface with an injection tool.

[0079] (A3) A porous fusion device as represented by (A1) or (A2), wherein the horizontal break is configured to disperse the applied force.

[0080] (A4) A porous fusion device as shown in (A1) to (A3), wherein the internal porous lattice structure comprises a variable density from the outer lattice cage of the porous fusion device to the center point.

[0081] (A5) A porous fusion device as shown in (A1) to (A4), wherein the variable density comprises a gradual decrease in density from the outer lattice cage of the porous fusion device to the center point.

[0082] (A6) A porous fusion device as shown in (A1) to (A5), wherein the outer lattice cage comprises one or more of an octagonal lattice, a heptagonal lattice, a hexagonal lattice or a pentagonal lattice.

[0083] (A7) A porous fusion device as shown in (A1) to (A6) further includes multiple material propagation channels arranged to pass through an inner porous lattice structure and an outer lattice cage.

[0084] (A8) A porous fusion apparatus as shown in (A1) to (A7) further includes a stop disposed opposite to a material injection port, the stop being configured to retain the injected material within the porous fusion apparatus.

[0085] (B1) A porous fusion device for fusing two or more tissues, comprising: an outer frame; an outer lattice cage disposed within the outer frame; an inner porous lattice structure disposed within the outer lattice cage; a material injection port disposed at the outer lattice cage and protruding into the inner porous lattice structure; and a plurality of material propagation channels disposed within the inner porous lattice structure and extending to the outer lattice cage, wherein the inner porous lattice structure comprises variable density tissue from the outer lattice cage of the porous fusion device to its central point, wherein the porous fusion device is configured to be backfilled with material after insertion into a patient.

[0086] (B2) A porous fusion device as shown in (B1), wherein a plurality of material propagation channels include at least one horizontal material propagation channel fluidly coupled to at least one vertical material propagation channel.

[0087] (B3) A porous fusion device as represented by (B1) or (B2), wherein at least one vertical material propagation channel extends through the outer frame.

[0088] (B4) A porous fusion device as shown in (B1) to (B3), wherein the material injection port further includes a threaded channel having a first threaded portion and a second threaded portion therebetween disposed therein.

[0089] (B5) A porous fusion device as shown in (B1) to (B4), wherein a plurality of material propagation channels include at least one horizontal material propagation channel fluidly coupled to at least one radially extending material propagation channel.

[0090] (B6) A porous fusion apparatus as shown in (B1) to (B5), wherein a plurality of material propagation channels are arranged to guide material toward two or more tissues.

[0091] (C1) A method of instructing the use of a porous fusion device, comprising: providing a porous fusion device including: an outer frame; an outer lattice cage disposed within the outer frame; an inner porous lattice structure disposed within the outer lattice cage; and a material injection port disposed at the outer lattice cage and protruding into the inner porous lattice structure; instructing the attachment of a material injection tool to the material injection port of the porous fusion device; instructing the insertion of the porous fusion device between at least two biological tissues; instructing the filling of at least a portion of the porous fusion device with material via the material injection tool; and instructing the disconnection of the material injection tool from the material injection port on the porous fusion device.

[0092] (C2) The method as represented in (C1), wherein the material injection port of the porous fusion device further includes a threaded channel, the threaded channel including a first threaded portion and a second threaded portion therebetween disposed therein.

[0093] (C3) The method as indicated in (C1) or (C2), wherein the instruction to fill at least a portion of the porous fusion device with material occurs before the instruction to insert the porous fusion device between at least two biological tissues.

[0094] (C4) The method as indicated in (C1) to (C3), wherein the material injected into the porous fusion device is a bone graft material.

[0095] (C5) The method as represented by (C1) to (C4) wherein the internal porous lattice structure of the porous fusion device is composed of a variable density organization from the outer lattice cage of the porous fusion device to the center point of the porous fusion device.

[0096] (C6) The method as represented by (C1) to (C5), wherein the porous fusion apparatus further includes a stop disposed opposite to the material injection port and configured to retain material injected into the porous fusion apparatus.

[0097] Many different arrangements of the various components depicted, as well as those not shown, are possible without departing from the scope of the claims below. Embodiments of this disclosure have been described, and are intended to be illustrative rather than restrictive. Alternative embodiments will become apparent to the reader of this disclosure upon reading it and upon reading it. Alternative means of implementing the foregoing can be accomplished without departing from the scope of the claims below. Certain features and sub-combinations are practical and can be employed without reference to other features and sub-combinations and are covered within the scope of the claims. Although this disclosure has been described with reference to embodiments illustrated in the accompanying drawings, it should be noted that equivalents may be employed and substitutions may be made herein without departing from the scope of this disclosure as set forth in the claims.

Claims

1. A porous fusion device, comprising: an outer frame; an outer lattice cage disposed within the outer frame; an inner porous lattice structure disposed within the outer lattice cage; and a material injection port disposed at the outer lattice cage and protruding into the inner porous lattice structure.

2. The porous fusion device of claim 1, wherein the material injection port comprises a threaded passage comprising a first threaded portion and a second threaded portion having a horizontal break therebetween, and wherein the material injection port is configured to interface with an injection tool.

3. The porous fusion device of claim 2, wherein the horizontal break is configured to disperse an applied force.

4. The porous fusion device of claim 1, wherein the inner porous lattice structure comprises a variable density from the outer lattice cage of the porous fusion device to a most central point.

5. The porous fusion device of claim 4, wherein the variable density comprises a gradual decrease in density from the outer lattice cage of the porous fusion device to the most central point.

6. The porous fusion device of claim 1, wherein the outer lattice cage comprises one or more of an octagonal lattice, a heptagonal lattice, a hexagonal lattice, or a pentagonal lattice.

7. The porous fusion device of claim 1, further comprising a plurality of material propagation channels disposed through the inner porous lattice structure and the outer lattice cage.

8. The porous fusion device of claim 1, further comprising a stop disposed opposite the material injection port, the stop configured to retain an injected material within the porous fusion device.

9. A porous fusion device for fusing two or more tissues, comprising: an outer frame; an outer lattice cage, disposed within the outer frame; an inner porous lattice structure disposed within the outer lattice cage; a material injection port disposed at the outer lattice cage and protruding into the inner porous lattice structure; and a plurality of material propagation channels disposed within the inner porous lattice structure and extending to the outer lattice cage, wherein the inner porous lattice structure is organized by a variable density from the outer lattice cage of the porous fusion device to a most central point, wherein the porous fusion device is configured to be backfilled with a material after insertion into a patient.

10. The porous fusion device of claim 9, wherein the plurality of material propagation channels comprises at least one horizontal material propagation channel fluidly coupled to at least one vertical material propagation channel.

11. The porous fusion device of claim 10, wherein the at least one vertical material propagation channel extends through the outer frame.

12. The porous fusion device of claim 11, wherein the material injection port further comprises a threaded passage having a first threaded portion and a second threaded portion having a break disposed therebetween. ​ ​ 13. The porous fusion device of claim 9, wherein the plurality of material propagation channels comprises at least one horizontal material propagation channel fluidly coupled to at least one radially extending material propagation channel.

14. The porous fusion device of claim 9, wherein the plurality of material propagation channels are arranged to direct the material toward the two or more tissues.

15. A method of instructing use of a porous fusion device, comprising: providing the porous fusion device, the porous fusion device comprising: an outer frame; an outer lattice cage disposed within the outer frame; an inner porous lattice structure disposed within the outer lattice cage; and a material injection port disposed at the outer lattice cage and protruding into the inner porous lattice structure; instructing attachment of a material injection tool to the material injection port of the porous fusion device; instructing insertion of the porous fusion device between at least two biological tissues; instructing filling of at least a portion of the porous fusion device with material via the material injection tool; and instructing disconnection of the material injection tool from the material injection port on the porous fusion device.

16. The method of claim 15, wherein the material injection port of the porous fusion device further comprises a threaded channel comprising a first threaded portion and a second threaded portion having a break disposed therebetween.

17. The method of claim 15, wherein instructing filling of at least a portion of the porous fusion device with the material occurs prior to instructing insertion of the porous fusion device between the at least two biological tissues.

18. The method of claim 15, wherein the material injected into the porous fusion device is a bone graft material.

19. The method of claim 15, wherein the inner porous lattice structure of the porous fusion device is organized by a variable density from the outer lattice cage of the porous fusion device to a most central point of the porous fusion device.

20. The method of claim 15, wherein the porous fusion device further comprises a stopper disposed opposite the material injection port and configured to retain the material injected into the porous fusion device.

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