Porous fusion device

1 . A porous fusion device, comprising:

an exterior frame;

an exterior lattice cage disposed within the exterior frame;

an interior porous lattice structure disposed within the exterior lattice cage,

wherein the interior porous lattice structure comprises a gradual decrease in density from the exterior lattice cage to a central-most point of the porous fusion device; and

a material injection port disposed at the exterior lattice cage and projecting into the interior porous lattice structure.

2 . The porous fusion device of claim 1 , wherein the material injection port comprises a threaded channel, the 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.

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

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

5 . The porous fusion device of claim 1 , further comprising a plurality of material propagation channels disposed through the interior porous lattice structure and the exterior lattice cage.

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

7 . The porous fusion device of claim 6 , wherein the backstop comprises a spanning channel disposed between a first portion of the backstop and a second portion of the backstop, the spanning channel configured to absorb compressive forces exerted on the porous fusion device.

8 . A porous fusion device for fusing two or more tissues, comprising:

an exterior frame;

an exterior lattice cage disposed within the exterior frame;

an interior porous lattice structure disposed within the exterior lattice cage;

a material injection port disposed at the exterior lattice cage and projecting into the interior porous lattice structure; and

a plurality of material propagation channels disposed within the interior porous lattice structure and extending to the exterior lattice cage,

wherein the interior porous lattice structure is organized by a variable density from the exterior lattice cage to a central-most point of the porous fusion device,

wherein the variable density comprises a gradual decrease in density from the exterior lattice cage to the central-most point of the porous fusion device,

wherein the porous fusion device is configured to be backfilled with a material following insertion into a patient.

9 . The porous fusion device of claim 8 , 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.

10 . The porous fusion device of claim 9 , wherein the at least one vertical material propagation channel extends through the exterior frame.

11 . The porous fusion device of claim 10 , wherein the material injection port further comprises a threaded channel having a first threaded portion and a second threaded portion with a break disposed therebetween.

12 . The porous fusion device of claim 8 , 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.

13 . The porous fusion device of claim 8 , wherein the plurality of material propagation channels is arranged to direct the material towards the two or more tissues.

14 . The porous fusion device of claim 8 , further comprising a backstop at least partially enclosing the exterior lattice cage, the backstop configured to retain injected material within the porous fusion device.

15 . A method of instructing use of a porous fusion device, comprising:

providing the porous fusion device comprising:

an exterior frame;

an exterior lattice cage disposed within the exterior frame;

an interior porous lattice structure disposed within the exterior lattice cage,

wherein the interior porous lattice structure of the porous fusion device is organized by a gradual decrease in density from the exterior lattice cage to a central-most point of the porous fusion device; and

a material injection port disposed at the exterior lattice cage and projecting into the interior porous lattice structure;

instructing attaching a material injection tool to the material injection port of the porous fusion device;

instructing inserting the porous fusion device between at least two biological tissues;

instructing filling at least part of the porous fusion device with a material via the material injection tool; and

instructing disconnecting 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 at least part of the porous fusion device with the material occurs prior to instructing inserting 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 bone graft material.

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

20 . The method of claim 15 , further comprising instructing adjustment of a viscosity of the material based at least in part on the density of the interior porous lattice structure.