Expandable tlif device and related insertion and grafting instrumentation

Abstract

To provide an interbody fusion device improved in mounting performance to an insertion instrument.SOLUTION: There is provided an interbody fusion device, including: a cage having a distal end, a proximal end, a base at the distal proximal end, and a hollow interior accessible through the base, the cage comprising an instrument attachment feature at the base including an outer wall at the proximal end of the cage and an inner wall spaced interiorly from the outer wall and defining therebetween a locking pocket, the inner wall having a first opening and the outer wall having a second opening, the first opening and the second opening being in communication with the hollow interior of the cage, the first opening with a dimension smaller than that of the second opening, the locking pocket having an extent extending behind a portion of the outer wall.SELECTED DRAWING: Figure 3D

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 63 / 127,316, filed December 18, 2020, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates generally to the field of spinal implants, and more particularly to an expandable transforaminal lumbar interbody fusion (TLIF) device and associated instrumentation for inserting the TLIF device into a patient's disc space and introducing graft material into the disc space after expansion of the device. [Background technology]

[0003] Spinal implants, such as interbody fusion devices, are used to treat degenerative disc disease and other injuries or defects of the intervertebral disc between adjacent vertebrae. The intervertebral disc may herniate or suffer from various degenerative conditions, in which case the anatomical function of the disc is disrupted. The most common surgical treatment for these conditions involves the fusion of the two vertebrae surrounding the affected disc. In most cases, a discectomy procedure removes the entire disc, except for a portion of the annulus fibrosus. A spinal fusion device is then introduced into the disc space, and a suitable bone graft or bone substitute is placed substantially within and / or adjacent to the device to promote fusion between the two adjacent vertebrae.

[0004] There are a variety of spinal fusion implants currently in use, some of which are expandable and others of fixed dimensions. To accommodate the spinal anatomy and promote articular fusion, it is preferable for the interbody fusion device to optimize contact with the adjacent vertebral endplates. This is usually accomplished by ensuring that the contact area between the device and the endplates of the opposing vertebrae has the greatest surface area feasible. Expandable interbody fusion devices have been used specifically for this purpose. With the advent of minimally invasive spinal surgery, further efforts have been made to further reduce trauma to the patient during spinal surgery. Thus, expandable interbody fusion devices have been sized and configured to smaller sizes for use in a posterolateral approach via what is known as Kambin's triangle. Further reductions in the size of interbody fusion devices typically result in smaller incisions, less blood loss, and faster patient recovery, among other things. Examples of intervertebral fusion devices sized and configured to be inserted into the Cambin triangle during introduction into the intervertebral disc space are shown in U.S. Patent No. 6,200,253, entitled "Expandable Intervertebral Device, and Systems and Methods for Inserting Same" by Scott J. Perrow, issued on April 9, 2016, which describes an expandable intervertebral fusion device that expands to increase the height of the intervertebral disc space, and U.S. Patent No. 6,200,253, entitled "Far Lateral Spacer" by Steve Wolfe et al., issued on December 19, 2017, which describes an expandable intervertebral fusion device that expands laterally within the intervertebral disc space.

[0005] While expandable interbody fusion devices sized and configured to fit into the Cambin triangle have several surgical advantages, they also create other challenges with respect to insertion of the device and subsequent introduction of the implant, particularly due to their relatively small size.

[0006] Therefore, there is a need to deploy an expandable interbody fusion device configured for use in a transforaminal lumbar interbody fusion (TLIF) procedure that is insertable into the interbody disc space via the Cambin triangle using an appropriate insertion implant instrument. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] U.S. Pat. No. 9,408,717 [Patent Document 2] U.S. Pat. No. 9,844,444 [Patent Document 3] U.S. Patent No. 10,492,925 [Patent Document 4] U.S. Pat. No. 5,473,138 [Patent Document 5] U.S. Patent No. 6,951,627 [Patent Document 6] U.S. Pat. No. 10,603,093 [Non-patent literature]

[0008] [Non-Patent Document 1] M. Hardenbrook et al., “The Anatomic Rationale for the Transforaminal Endoscopic Interbody Fusion: a Cadaveric Analysis,” Neurosurgical Focus 40, February 2016. Summary of the Invention [Problem to be solved by the invention]

[0009] It is an object of the present invention to provide an interbody fusion device with improved attachment capabilities to an insertion tool.

[0010] Another object of the present invention is to provide an improved interbody fusion apparatus that includes an interbody fusion device and instrumentation attachable to the device for inserting the interbody fusion device into the intervertebral disc space.

[0011] It is a further object of the present invention to provide improved instruments for inserting interbody fusion devices into the intervertebral disc space and delivering graft material thereto.

[0012] It is yet another object of the present invention to provide a process for forming a textured surface on the upper and lower surfaces of an interbody fusion device. [Means for solving the problem]

[0013] In order to solve the above problems, the interbody fixation device of the present invention comprises a cage having a distal end, a proximal end, a base at the distal end, and a hollow interior accessible through the base, the cage comprising an instrument attachment mechanism at the base having an outer wall at the proximal end of the cage and an inner wall spaced inwardly from the outer wall and defining a locking pocket between the outer wall and the inner wall, the inner wall having a first opening and the outer wall having a second opening, the first opening and the second opening are in communication with the hollow interior of the cage, the first opening is of a smaller diameter than the second opening, and the locking pocket has a length extending behind a portion of the outer wall.

[0014] In one embodiment, the cage has a height and a width that intersect and define four corners of the cage, with opposite diagonal corners defining an axis that forms an acute angle with both the height and the width.

[0015] In one embodiment, the second opening has a first, longer length along the axis and a second, shorter length transverse to the axis.

[0016] In one aspect, the second opening has a circular portion and a pair of arcuate-shaped lobes extending radially from the circular portion in opposite directions along the axis, the arcuate-shaped lobes defining the longer first length along the axis and the circular portion defining the shorter length.

[0017] In one aspect, the locking pocket has a circular portion aligned with the circular portion of the second opening and a pair of extending lobes extending radially from the circular portion in opposite directions along the axis, the extending lobes being in communication with the lobes of the second opening for an arc-shaped portion and extending beyond the lobes of the second opening to a position behind the portion of the outer wall for a further arc-shaped portion.

[0018] In one embodiment, the first opening defines an implantation opening having a circular configuration, the height and the width of the cage define a cross-sectional area of ​​the cage, and the implantation opening has an area that is greater than or equal to about 29% of the cross-sectional area of ​​the cage.

[0019] In one aspect, the cage is configured to be expandable.

[0020] In one aspect, the cage is configured to be expandable in both height and width.

[0021] In one embodiment, the cage comprises four moveable arms hinged to the cage at the base.

[0022] In one aspect, the arms of the cage are biased outwardly in the height and width directions at the distal end of the cage by a wedge that is movable within the cage toward the distal end.

[0023] In one aspect, the cage is sized in the unexpanded state to be introduced into the disc space in a posterolateral approach via the Cambin triangle for a transforaminal lumbar interbody fusion (TLIF) procedure.

[0024] In one aspect, the cage has an upper surface and an opposing lower surface, the upper surface and the lower surface comprising a textured surface.

[0025] An interbody fusion device according to the present invention also comprises a cage having a distal end, a proximal end, a base at the distal end, and a hollow interior accessible through the base, the cage comprising an instrument mounting mechanism at the base with an outer wall at the proximal end of the cage having an instrument mounting opening in communication with the hollow interior of the cage, the cage having a height and width that intersect to define four corners of the cage, opposite diagonal corners defining an axis that forms an acute angle with both the height and the width, the instrument mounting opening having a first length that is longer along the axis and a second length that is shorter transverse to the axis. Interbody fusion devices.

[0026] In one aspect, the cage is formed from titanium.

[0027] In one aspect, the cage has an upper surface and an opposing lower surface, the upper surface and the lower surface comprising a textured surface.

[0028] In one aspect, the textured surface is a laser ablated surface.

[0029] In one aspect, the cage is configured to be expandable.

[0030] In one aspect, the cage is configured to be expandable in both height and width.

[0031] In one embodiment, the cage comprises four moveable arms hinged to the cage at the base.

[0032] In one aspect, the arms of the cage are deflectable outwardly in the height and width directions at the distal end of the cage by a wedge that is movable within the cage toward the distal end. [Brief description of the drawings]

[0033] [Figure 1] FIG. 1 illustrates an exploded, front perspective view of an expandable interbody fixation device according to one embodiment of the present invention and associated instrumentation for attachment to and use with the device according to one embodiment of the present invention. [Diagram 2] 2 is an enlarged view of FIG. 1 showing the expandable interbody fixation device and a portion of the distal end of the instrument. [Figure 3A] FIG. 2 is a top view of the interbody fusion device of FIG. 1. [Figure 3B] FIG. 2 is a side elevational view of the interbody fusion device of FIG. 1. [Figure 3C] FIG. 2 is a posterior elevational view of the interbody fusion device of FIG. 1. [Figure 3D] 2 is a top posterior perspective view of the interbody fusion device of FIG. 1. [Figure 3E] 3B is a cross-sectional view of the interbody fusion device taken along line AA of FIG. 3A. [Figure 3F] 3B is a cross-sectional view of the interbody fixation device taken along line BB of FIG. 3A. [Figure 3G] 3C is a cross-sectional view of the interbody fixation device taken along line CC of FIG. 3B. [Figure 4A] 2 is a top anterior perspective view of a wedge for expanding the interbody fixation device of FIG. 1. [Figure 4B] FIG. 4B is a front elevational view of the wedge of FIG. 4A. [Figure 4C] FIG. 4B is a side elevational view of the wedge of FIG. 4A. [Diagram 5] FIG. 3 is a further view showing the interbody fusion device of FIG. 2 and the distal end of the instrument moved into alignment with the interbody fusion device for attachment thereto. [Figure 6A]13A-13D show images of the process of instrumenting an interbody fusion device. [Figure 6B] 13A-13D show images of the process of instrumenting an interbody fusion device. [Figure 7] FIG. 2 is an exploded top front perspective view of the device of FIG. 1; [Figure 8] FIG. 8 is an enlarged exploded view of a portion of the device of FIG. [Figure 9A] FIG. 13 is an exploded perspective view of a sectioned portion of the instrument handle showing details of the locking structure for locking the instrument relative to the interbody fusion device with the locking button in the locked position. [Figure 9B] FIG. 9B is a side cross-sectional view of the portion of the instrument handle shown in FIG. 9A. [Figure 9C] FIG. 9B is a longitudinal cross-sectional view of the portion of the instrument handle shown in FIG. 9A. [Figure 10A] FIG. 9B is a further view of FIG. 9A showing the locking button in an unlocked position. [Figure 10B] FIG. 9C is a further view of FIG. 9B showing the locking button in the unlocked position. [Figure 11] 10B is a further view similar to FIG. 10A with the locking handle moved into a position allowing the instrument to be separated from the interbody fusion device. [Figure 12] 2 is a further view of FIG. 1 showing the installed interbody fusion device and instrument with the locking handle in the installed vertical position. [Figure 13A] 2 is a top anterior perspective view of the interbody fusion device of FIG. 1 in an expanded state. [Figure 13B] FIG. 10B is a top view of the expanded interbody fusion device of FIG. 10A. [Figure 13C] FIG. 13B is an anterior elevational view of the expanded interbody fixation device of FIG. 13A. [Figure 14] 13 is a further view of FIG. 12 showing an implant delivery cartridge holding multiple implant pellets positioned laterally within the instrument for individual delivery of the implant pellets to an expanded interbody fusion device. [Figure 15] FIG. 15 is a cross-sectional view of the device of FIG. 14 taken along line XV-XV. [Figure 16] FIG. 2 is a plan view of an unexpanded interbody fusion device having surface texturing in accordance with one particular aspect of the device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] For the purposes of familiarizing and understanding the principles of the invention, reference will hereinafter be made to the embodiments illustrated in the drawings and described in the following specification, it being understood that no limitation of the scope of the invention is intended, and it is further understood that the invention encompasses all alterations and modifications of the illustrated embodiments and other applications of the principles of the invention as would normally occur to one skilled in the art to which the invention pertains.

[0035] 1, an expandable interbody fusion device 10 and associated instrumentation 200 for use in inserting the device 10 into a disc space, expanding the device 10, and delivering graft material into the device 10 once it is expanded within the disc space are illustrated. In one particular configuration, the device 10 and instrumentation 200 are sized and configured for introduction of the device 10 in a posterolateral approach via the Cambin Triangle in a transforaminal lumbar interbody fusion (TLIF) procedure. The Cambin Triangle is well known and is defined as a right angle triangle on the dorsolateral side of the disc, where the hypotenuse of the triangle is the external nerve root, the base (width) of the triangle is the superior border of the caudal vertebrae, and the height of the triangle is the internal nerve root (see, e.g., "Interbody fusion: A guide to the development of interbody fusion in spinal cord surgery," Journal of Neurosurgery, 1999, 144: 111-115, which is incorporated herein by reference). As will be described below, device 10 is small enough to fit into the Cambin triangle, yet expandable both vertically to accommodate spinal lordosis and laterally to provide sufficient structural support for the opposing vertebral bodies within the disc space. It should be understood that while device 10 is configured for use as a spinal implant specifically in a TLIF procedure, it is not limited to use via the Cambin triangle, and thus may also be used as an expandable interbody fusion device that may be introduced in other approaches, such as posteriorly, anteriorly, and laterally at various levels of the spine, or percutaneously.

[0036] 2 and 3A-3G, the expandable interbody fusion device 10 will now be described in detail. The device 10 comprises a cage 12 having a hollow interior 12f and a wedge 100 slidable within the hollow interior 12f. The cage 12 has a distal end 12a and a proximal end 12b. The cage 12 has a generally elongated shape defining a longitudinal axis 12c extending through the distal end 12a and the proximal end 12b as shown in FIG. 3A. The wedge 100 is sized and configured to be slidable within the cage 12 to expand the cage 12, as described hereinafter. The cage 12 comprises a base 14 at its proximal end 12b and a plurality of flexible, movable arms 16 projecting from the base 14 toward the distal end 12a. The arms 16 are free and not attached to one another at the distal end 12a, thus allowing the cage 12 to expand at the distal end 12a. In the illustrated configuration, the cage 12 has four movable arms 16, including a pair of upper arms 16a and 16b and a pair of lower arms 16c and 16d. The arms 16 are attached to the base 14 at hinge points 18a, 18b, 18c (not shown), and 18d, respectively, in a manner that allows for deflection of the arms 16 in two lateral directions relative to the base 14. The cage 12 further comprises an upper opening 11 between the arms 16a and 16b, a lower opening 13 between the arms 16c and 16d, and a pair of side openings, one opening 15 of which is between the arms 16a and 16c and the other opening 17 of which is between the arms 16b and 16d (see also Figures 13A and 13B). In use, these lateral directions may be mutually orthogonal, i.e., vertically to accommodate lordosis within the disc space by expanding the device height at the distal end 12a, and horizontally to increase the device width and thus provide enhanced lateral support to opposing vertebral bodies within the disc space. In FIG. 3C, the unexpanded device height H1 and unexpanded device width W1 are shown. In one particular configuration, the cage 12 may be monolithically formed as a unitary device having a square shape, as shown in FIG. 3D.It should be appreciated that other cage shapes, such as cylindrical, may also be used.

[0037] As shown in Figures 2 and 3G, upper and lower arms 16a and 16c respectively include inclined cam surfaces 20a and 20c which face each other vertically for cooperative engagement with wedge 100. Upper and lower arms 16b and 16d also include similar inclined cam surfaces 20b and 20d which face each other vertically for cooperative engagement with wedge 100 as shown in Figures 2 and 3B. Upper and lower arms 16a and 16b further include inclined cam surfaces 22a and 22b respectively which face each other laterally for cooperative engagement with wedge 100 as shown in Figure 3A. Each of the lower arms 16c and 16d also includes a similar angled cam surface 22c and 22d that laterally face each other for cooperative engagement with the wedge 100, as shown in Figure 3G. Each of the lower arms 16c and 16d further includes a locking notch 23c and 23d, as shown in Figure 3G, and each of the upper arms 16a and 16b further includes a locking notch 23a (not shown) and 23b, as shown in Figure 3B. These locking notches 23a, 23b, 23c, and 23d are disposed adjacent the distal end 12a of the cage 12 to receive portions of the wedge 100 to lock the arms 16 in the extended position of the cage 12.

[0038] 4A-4C, the wedge 100 will now be described in detail. The wedge 100 serves as an expander for the device 10 and is sized and configured to be movably received within the cage 12 for expanding the distal end 12a of the cage 12 upon distal movement. The wedge 100 has a generally cross shape and a threaded hole 101 extending generally through the center of the wedge 100 for threadedly engaging with a threaded shaft of an instrument 200 as described below. The wedge 100 has a vertical section 102 and a transverse horizontal section 104, which are orthogonal to one another in one particular configuration. The vertical section 102 has angled side surfaces 102a and 102b formed above the horizontal section 104 and angled side surfaces 102c and 102d formed below the horizontal section 104. During movement of wedge 100 within cage 12 toward distal end 12a, curved side surfaces 102a and 102b are configured to engage angled camming surfaces 22a and 22b, respectively, on upper arms 16a and 16b, and angled side surfaces 102c and 102d are configured to engage angled camming surfaces 22c and 22d, respectively, on lower arms 16c and 16d, as shown in Figure 3A. Such movement of wedge 100 and its cooperative engagement with cage 12 causes the distal ends of arms 16a, 16b, 16c, and 16d to bend laterally away from midline 12c in a cantilevered manner about hinge points 18a, 18b, 18c, and 18d, thereby expanding the width of cage 12 at distal end 12a.

[0039] The horizontal section 104 has curved upper surfaces 104a and 104b formed on either side of the vertical section 102 above the horizontal section 104, and curved lower surfaces 104c and 104d formed on either side of the vertical section 102 below the horizontal section 104. Thus, as shown in FIG. 3B, during movement of the wedge 100 within the cage 12 toward the distal end 12a, the curved upper surface 104b is configured to engage the angled cam surface 20b on the upper arm 16b, and the curved lower surface 104d is configured to engage the angled cam surface 20d on the lower arm 16d. Similarly, the curved upper surface 104a is configured to engage the angled cam surface 20a on the upper arm 16a, and the curved lower surface 104c is configured to engage the angled cam surface 20c on the lower arm 16c. Such movement of wedge 100 and cooperative engagement with cage 12 causes the distal ends of arms 16a, 16b, 16c, and 16d to bend vertically away from midline 12c in a cantilevered manner about hinge points 18a, 18b, 18c, and 18d, thereby expanding the height of cage 12 at distal end 12a. Additionally, curved upper surfaces 104a and 104b terminate at engagement edges 106a and 106b, respectively, and curved lower surfaces 104c and 104d terminate at engagement edges 106c and 106d, respectively, which are configured to lock cage 12 in an extended position by engaging and seating within respective locking notches 23a, 23b, 23c, and 23d, as will be described hereinafter.

[0040] In one particular configuration, the wedge 100 and the angled cam surfaces 20a-20d and 22a-22d on the arms 16a-16d are configured and oriented in a manner to move the arms 16 simultaneously. It should be understood that the angled surfaces 20a-20d and 22a-22d may also be configured and oriented relative to the wedge 100 to effect sequential movement, whereby the arms 16 are first moved laterally and then vertically, or vice versa as desired.

[0041] Both the cage 12 and the wedge 100 are formed from suitable metallic or polymeric biomaterials. Suitable biocompatible metallic materials include pure titanium, tantalum, cobalt chromium alloys, titanium alloys (e.g. nickel titanium alloys and tungsten titanium alloys), stainless steel alloys, molybdenum rhenium (MoRe), and NiTinol (superelastic properties). Suitable polymeric materials include, for example, polyetheretherketone (PEEK), carbon reinforced PEEK, members of the polyaryletherketone (PAEK) family such as polyetherketoneketone (PEKK), polysulfone, polyetherimide, polyimide, ultra-high molecular weight polyethylene (UHMWPE), or cross-linked UHMWPE. Such polymers may include ceramic materials such as aluminum oxide or alumina, zirconium oxide or zirconia, particulate diamond compacts, or pyrolytic carbon. It is understood that these materials may be used individually or in combination as desired.

[0042] 3C, 3D, 3E, and 3F, and 5, the details of the mounting of the expandable interbody fusion device 10 and the instrument 200 will be described. As mentioned above, in one particular configuration, the device 10 is sized and configured to fit into the intervertebral disc space via the Cam Bin Triangle. As a result, the cross-sectional profile of the device 10, as defined by the height and width of the device 10, is dimensioned in a manner that allows for use via the Cam Bin Triangle. Furthermore, since at least the distal end of the instrument 200 for inserting the device 10 may further need to be inserted into the Cam Bin Triangle, the distal end of the instrument 200, including the mounting end 202, is similarly dimensioned to accommodate introduction via the Cam Bin Triangle. In this manner, the instrument 200 is configured to be mounted against the proximal end 12b of the cage 12, with at least the distal end of the instrument 200 having a maximum dimension within the limitations of the outer cross-sectional profile of the cage 12.

[0043] While the outer cross-sectional profile of the cage 12 is sized to be as small as feasible for introduction through the Cambin triangle, the inner opening of the cage 12 is desirably sized to be as large as feasible to facilitate subsequent introduction of the graft into the expanded cage 12. As an example, when sized and configured for a TLIF fixation procedure at the L1 / L2 lumbar level, the unexpanded height H1 of the cage 12 as shown in FIG. 3C may be 8.0 mm and the unexpanded width W1 may be 8.5 mm. This dimensioning in this example results in an outer cross-sectional profile that is approximately square. To maximize graft access into the cage 12, the inner graft circular opening 24 may be sized to have a diameter of at most about 5.0 mm. This dimensioning results in a ratio of graft opening area to cage 12 cross-sectional area of ​​at least at least about 29%. While these dimensions and minimum graft aperture ratios are desirable for graft delivery, such dimensions leave relatively little material for either height or width attachment of cage 12 to device 200. Thus, opposing diagonal corners 12d as shown in FIG.

[0044] FIG. 5 shows the mounting portion 202 of the instrument 200 oriented in a position that allows for fixed mounting to the cage 12. The instrument 200, which will be described in more detail below, includes an outer tube 204 that supports a rotatable cylindrical inner tube 206. In one particular configuration, the outer tube 204 may have a rectangular cross-section that is equal to or smaller than the cross-section of the unexpanded cage 12. The inner tube 206 includes a mounting portion 202 at its distal end. The mounting portion 202 includes a pair of lugs 208 that project radially outwardly from the inner tube 206 in diametrically opposed directions. As also shown in FIG. 3D, the cage 12 includes an instrument mounting mechanism 13 at the base 14, which includes an outer wall 26 at the proximal end 12b and an inner wall 28 spaced inwardly from the outer wall 26. The inner wall 28 includes an implantation opening 24 in communication with the cage hollow interior 12f. The outer wall 26 includes an entrance opening 30 in communication with the graft opening 24 and the cage hollow interior 12f. The entrance opening 30 has a configuration different from that of the graft opening 24, and in one particular configuration, has a circular portion 30a and a pair of arc-shaped lobes 30b that project radially outward from the circular portion 30a in diametrically opposed directions. The lobes 30b are configured to be disposed along a diagonal axis 12e that extends toward both corners 12d of the cage 12 as shown in FIG. 3C. In this configuration, the axis 12e forms an acute angle with both the height and width of the cage 12. The circular portion 30a of the entrance opening 30 is sized to relatively closely receive the cylindrical inner tube 206 of the instrument 200, and the lobes 30b are sized to relatively closely receive respective lugs 208 on the cylindrical inner tube 206. While the mounting portion 202 of the device 200 can be received through the entrance opening 30, the implantation opening 24 is sized to be smaller in dimension than the circular portion 30a of the entrance opening 30, so that the mounting portion 202 of the device 200 cannot pass through the implantation opening 24 in the inner wall 28.

[0045] In one configuration, the inlet opening 30 is formed to have a circular portion with opposing lobes, although it should be understood that other shapes of inlet opening 30 may be provided. For example, the inlet opening 30 may be formed in an elliptical shape or other shape having a longer length along the diagonal axis 12e and a shorter length transverse to the diagonal axis 12e.

[0046] The space between the outer wall 26 and the inner wall 28 defines a locking pocket 32 ​​as shown in Figures 3D and 3F. The locking pocket 32 ​​has a circular portion 32a configured to receive the cylindrical inner tube 206 of the instrument 200 and a pair of extending lobes 32b extending radially outward from the circular portion 32a. The extending lobes 32b are configured to have a greater arc length along the circumference of the circular portion 32a than the lobes 30b of the inlet opening 30. Thus, the extending lobes 32b communicate in alignment with the lobes 30b for some arcs and extend further in the arc in a non-aligned manner with the lobes 30b further into the outer wall 26. Thus, once the inner tube 206 extends past the inlet opening 30 as shown in FIG. 6A, it can be rotated at an appropriate angle to move the lug 208 in an arc within the extension lobe 32b until it is located between the inner wall 28 and the outer wall 26 as shown in FIG. 6B. In the specific example of a cage 12 having an unexpanded height H1 of 8.0 mm and a width W1 of 8.5 mm, the inner tube 206 can be rotated approximately 41° to move the lug 208 to a position between the inner wall 28 and the outer wall 26. The transition point 32c between the circular portion 32a and the extension lobe 32b as shown in FIG. 3F can act as a mechanical stop when engaged by the lug 208, thereby preventing further rotation of the attachment portion 202 within the locking pocket 32. In this position, the attachment portion 202 cannot be withdrawn from the cage 12 and can be fixedly locked thereto, as will be described below.

[0047] 7 and 8, further details of the instrument 200 will be described. The instrument 200 includes an elongated instrument handle 210, an outer tube 204, an inner tube 206, and a wedge driver 212. As previously mentioned, the outer tube 204 may have a rectangular cross-section at its distal end 204a that is equal to or less than the cross-sectional size of the unexpanded cage 12. The remaining length of the outer tube 204 may have a cylindrical outer surface 204c. The outer tube 204 has an inner lumen 204b extending longitudinally therethrough. The inner tube 206 includes a mounting portion 202 at its distal end 206a that includes a pair of lugs 208 as described above. The inner tube 206 has a cylindrical outer surface 206d for sliding engagement within the lumen 204b of the outer tube 204. The inner tube 206 has an interior lumen 206b extending longitudinally therethrough. A locking handle 214 is provided at a proximal end 206c of the inner tube 206. The locking handle 214 is fixed relative to the inner tube 206 for rotation and axial movement therewith, and includes a radially projecting shaft 214a terminating in a locking lever 214b which facilitates manual rotation of the locking handle 214, and thus the inner tube 206, as described hereinafter.

[0048] The wedge driver 212 includes an elongated cylindrical shaft 212a having a distal end 212b and a proximal end 212c. The cylindrical shaft 212a is sized and configured to slidingly extend within the lumen 206b of the inner tube 206. A threaded portion 212d is provided at the distal end 212b of the shaft 212a and is configured to threadably engage the threaded hole 101 of the wedge 100, as described below. An enlarged cylindrical portion 212e is disposed at the proximal end 212c of the wedge driver 212.

[0049] 8, the handle 210 includes a handle body 210a, a handle cover 210b, and an end cap 211. The handle cover 210b is suitably attached to the handle body 210a by fasteners such as a set of four screws 216. The end cap 211 may be suitably attached and oriented to the handle body 210a by a key 213 formed in the proximal end of the handle body 210a. The handle 210 fixedly supports the outer tube 204 at its distal end and includes a channel 210c adjacent its distal end for receiving and supporting the inner tube 206. An opening 211a extends through the end cap 211 in alignment with an opening 210d through the proximal end of the handle body 210a for receiving a portion of the T-handle for driving the wedge driver 212 axially distally as described hereinafter. A cam element 218 is supported in a pocket 220 defined by ledges 222 and 224 at the distal end of the handle body 210a. The cam element 218 has an angled cam surface 218a that faces proximally for interfacing with a cam surface 214c of the locking handle 214 as described below (see FIGS. 9B and 10B). The cam element 218 may be secured in the pocket 220 by a suitable fastening member such as, for example, screws 226 and 228. The handle body 210a supports a depressible locking button 230 adjacent the distal end of the handle body 210a for pivoting within the handle body 210a. The locking button 230 may be spring biased by a compression spring 232 captured in a recess 210e that normally biases the locking button 230 to a locked position as described below. The handle body 210a also includes an opening 234 adjacent the cam element 218 that is configured and sized to receive the shaft 214a of the locking handle 214 therein to limit rotational movement relative to the handle body 210a. The handle body 210a further supports a drive nut 236.The drive nut 236 may have a substantially rectangular configuration to be received and retained within a matching rectangular recess 238 formed within the handle body 210a. With the handle cover 210b attached to the handle body 210a, the drive nut 236 is properly retained within the handle 210 and prevented from either axial or rotational movement within the handle 210. In one particular configuration, the drive nut 236 includes internal threads 236a for engaging a suitable tool for driving the wedge driver 212, and thus the wedge 100, axially distally to expand the cage 12, as described hereinafter. A relatively flat surface 240 may be formed on the proximal end of the handle end cap 211 to allow for some tapping to aid in the insertion of the interbody fusion device 10 into the disc space.

[0050] 7 and 8, in certain embodiments, the handle 210 of the instrument 200 may be formed to receive an implant cartridge to facilitate introduction of implant material into the expanded device 10, as will be further described below. In this regard, the handle body 210a and handle cover 210b are formed with side openings 215 and 217, respectively, for laterally receiving a cartridge containing implant material. A movable releasable detent 242, which may be manually depressible upon application of a lateral force to the cartridge, may be supported within a recess 244 in the handle body 210a.

[0051] 9A-9C, 10A-10B, and 11, further details and function of the locking button 230 will be described. FIGS. 9A-9C show the locking button 230 in a normal, locked position. The locking button 230 is rotatably supported within the handle 210 by a pivot pin 246. The locking button 230 includes a depressible portion 230a at one end thereof and a protruding lock 230b at an opposing end. The depressible portion 230 may be of a circular configuration or other suitable shape and is accessible to a user through an opening 248 in the handle 210. In the position shown in FIGS. 9A, 9B, and 9C, the biasing spring 232 biases the depressible portion 230a downward, thereby biasing the lock 230b upward, thereby urging the free end 230c of the lock 230b into the locking groove 214d of the locking handle 214. 10A and 10B show the locking button 230 in the unlocked position. A user can manually push the depressible portion 230a upward to move the lock 230b at the opposite end downward, thereby moving the free end 230c of the lock 230b out of the locking groove 214d of the locking handle 214. In this position, the locking handle 214 can rotate freely within the handle opening 234 as shown in FIG. 11, thereby rotating the inner shaft 206 relative to the handle 210. In this position, the free end 230d of the lock 230b can be located within the second groove 214e of the locking handle 214, which can be overcome by rotating the locking handle 214 back to the locked position. The position of the locking handle 214 in FIG. 11 is the same as the position of the locking handle 214 as shown in FIG. 1.

[0052] Having described the details of the interbody fusion device 10 and the instrument 200, the use of the instrument 200 to insert the device 10 into the disc space between two opposing vertebral bodies, expand the device 10 therein, and facilitate graft delivery into the expanded device 10 will now be described. An incision is made through the patient's tissue to establish a working corridor to a spinal surgical site, for example via the Cambin triangle, for a TLIF procedure. This corridor may be created with appropriate instruments, and the disc space may be appropriately prepared via the corridor for insertion of the interbody fusion device 10. As shown in FIG. 2, the instrument 200 without the wedge driver 212 may be mounted to the device 10 by first aligning the lugs 208 on the mounting end 202 of the inner tube 206 against the lobes 30b of the openings 30 in the outer wall 26 of the cage 12. The attachment end 202 may then be inserted into the cage 12 through the opening 30 as shown in FIG. 5 and into the locking pocket 32 ​​with the lug 208 located in the extending lobe 32b as shown in FIG. 6A. At this point, the locking handle 214 is in an angular position relative to the handle 210 as shown in FIG. 1. The locking handle 214 is then manually rotated in a clockwise direction as viewed from the proximal end of the instrument 200 toward the patient until it is in a vertical position as shown in FIGS. 9A-9C and 12. A structural feature, such as a protrusion 204d (see FIGS. 2 and 5) on the distal end of the outer tube 204 enters and engages the lobe 30b at the proximal end of the device 10, thereby preventing relative rotation between the outer tube 204 and the device 10 during rotation of the locking handle 214. In the above example of a cage 12 having an unexpanded height H1 of 8.0 mm and a width W1 of 8.5 mm, the locking handle 214 may be rotated approximately 41°. During rotation of the locking handle 214 to a vertical position, the shaft 214a of the locking handle 214 engages the locking button 230 and urges the locking button 230 axially in a proximal direction against the bias of the spring 232.When the locking handle 214 reaches the vertical position shown in FIG. 12, the free end 230c moves out of the secondary groove 214e of the locking handle 214 allowing the locking button 230 to snap the free end 230c of the lock 230b into the locking groove 214d, thereby locking the locking handle 214 in that position until the locking button 230 is manually pushed upwardly relative to the handle 210.

[0053] During such rotation of the locking handle 214, the lug 208 is moved in an arc to extend into the extending lobe 32b behind the outer wall 26, as shown in FIG. 6B. In this position, the proximal wall 26 is captured between the lobe 208 and the distal end 204a of the outer tube 204 of the instrument 200. At the same time during such rotation, the cam surface 214c on the locking handle 214 slidingly engages the cam surface 218a on the cam element 218, causing the inner tube 206, which is fixedly attached to the locking handle 214, to move slightly axially proximally relative to the handle 210. This amount of axial proximal movement of the inner tube 206 is sufficient to cause the outer wall 26 to be sandwiched between the lobe 208 at the distal end of the inner tube 206 and the distal end 204a of the outer tube 204. When the locking handle 214 reaches the vertical position shown in FIG. 12, sufficient compressive force is applied against the outer wall 26 to securely clamp the instrument 200 against the cage 12 of the device 10 .

[0054] Once the instrument 200 is attached to the cage 12, the instrument 200 is used to insert the device 10 into a suitably prepared disc space. The flat surface 240 of the instrument handle 210 may be appropriately tapped or struck to gently urge the device 10 into the disc space, as desired by the surgeon. The wedge driver 212 is then introduced into the lumen 206b of the inner tube 206, and the threaded portion 212d is manually threaded into the threaded hole 101 of the wedge 100 to properly attach the wedge 100 to the wedge driver 212. Alternatively, depending on the surgeon's practice, the wedge driver 212 may be attached to the wedge 100 prior to the introduction of the device 10 into the disc space. Once attached, the wedge driver 212 may be appropriately driven axially distally to push the wedge 100 axially distally within the cage 12 to expand the cage 12 within the disc space as described above. Wedge 100, which is initially disposed approximately centered between distal end 12a and proximal end 12b of cage 12, is moved toward distal end 12a until engagement edges 106a, 106b, 106c, and 106d engage and seat within respective locking notches 23a, 23b, 23c, and 23d, thereby locking cage 12 in the expanded position as shown in FIG. 13A.

[0055] A suitable tool for axially driving the wedge driver 212 and thus the wedge 100 may be a T-handle (not shown). Such a T-handle may have an elongated cylindrical tube with an external thread at a distal end. The T-handle may be configured such that the cylindrical tube slides within the opening 211a of the handle end cap 211 until the external thread at the distal end of the T-handle threads into the internal thread 236a of the drive nut 236. An internal transverse axial surface may be provided within the T-handle for engaging the extended cylindrical portion 212e at the proximal end 212c of the wedge driver 212. Appropriate rotation of the T-handle moves the T-handle axially distally relative to the handle 210 under the influence of the threaded engagement between the external thread of the T-handle and the internal thread 236a of the drive nut 236, whereby the internal transverse axial surface of the T-handle presses against the extended cylindrical portion 212e, thereby pushing the wedge driver 212 axially distally. Such rotation of the T-handle continues until the cage 12 is properly expanded as shown in Figures 13A-13C and the wedges 100 are properly locked within the locking notches 23a-23d.

[0056] After the interbody fusion device 10 has been expanded, the wedge driver 212, and T-handle, if used, may be removed from the instrument 200, which remains attached to the expanded device 10. Implant material may be introduced into the expanded interbody fusion device 10 using the instrument 200. As shown in FIGS. 14 and 15, an elongated cartridge 300 containing a plurality of individually spaced pellets 302 of implant material may be slidably inserted into a side opening 215 of the instrument handle 210 as shown in FIG. 14. The cartridge 300 may contain any suitable number of individual pellets 302, with five pellets shown in FIG. 15. The cartridge 300 includes a plurality of recesses 304, each recess 304 associated with and aligned with one of the individual pellets 302. Each recess 304 is configured to receive a releasable detent 242 as shown in FIG. 15. Receiving a detent 242 within each recess 304 temporarily holds the cartridge 300 in a position such that one of the pellets is aligned with the inner lumens 206b and 204b of the inner and outer tubes 206 and 204, respectively. A manual force is applied laterally to the cartridge 300 to resolve this temporary position by moving the detent 242 laterally out of each recess 304 and further into the handle 210 until another recess 304 is aligned with the detent 242. The cartridge 300 can be moved laterally through the handle 210 until it emerges through an opening 217 on the opposite side of the handle 210, at which time it can be removed. With each pellet 302 aligned with the inner tube 206 and outer tube 204, a suitable plunger 250 can be introduced through the opening 211a in the handle end cap 211 to individually push the pellets 302, one at a time, through the implant opening 24 into the internal hollow portion 12f of the expanded interbody fixation device 10 until sufficient implant material has been placed.As noted above, in some instances, the implant opening 24 of the cage 12 of the interbody fusion device 10 may be configured to have a diameter of up to about 5.0 mm, which facilitates effective and easy delivery of an appropriate amount of implant material. Once the implant fills the internal hollow 12f, it may pass further through the cage top opening 11 and bottom opening 13 to contact the vertebral endplates of the opposing vertebral bodies to facilitate fixation to the vertebral bodies. The implant may also pass out of the cage side openings 15 and 17 to fill the disc space adjacent to the cage 12 to facilitate further fixation to the opposing vertebral bodies.

[0057] As an alternative, a separate graft delivery device may be used in combination with the instrument 200 to deliver the appropriate amount of graft material to the surgical site and into the expanded device 10. One such suitable graft delivery device is described in commonly assigned US Patent No. 5,339,393 (the '925 patent) to Hollister et al., issued Dec. 3, 2019, the entire contents of which are incorporated herein by reference. The graft delivery device described in the '925 patent is commercially available under the trade name GraftMag. In use, the channel 12 described in the '925 patent may be introduced through the inner tube 206 of the instrument 200 to place the graft into the device 10 via the opening 30 in the cage 12.

[0058] Once the appropriate implant has been delivered and the surgical procedure is completed, the instrument 200 may then be disengaged from the expanded cage 12. To accomplish such disengagement, the depressible portion 230a of the locking button 230 is manually pushed upwardly to release the lock 230b from the locking groove 214d as described above, thereby allowing the locking handle 214 to be moved radially within the opening 234 of the handle 210 to the angular position shown in FIG. 1. During such movement, compression of the cage outer wall 26 between the lugs 208 and the distal end 204a of the instrument outer tube 204 is released while the lugs 208 are moved radially back into alignment with the lobes 30b. At this point, the instrument 200 may be withdrawn from the expanded device 10 and from the surgical site.

[0059] In the example shown above for use in a TLIF fusion procedure at the L1 / L2 lumbar level, the cage 12 may have an unexpanded height H1 of 8.0 mm and an unexpanded width W1 of 8.5 mm. Upon expansion, the distal end 12a of the cage may increase to an expanded height H2 of 10 mm and an expanded width W2 of 11 mm, as shown in Figures 13A, 13B, and 13C. The increased height to H2 results in a lordotic angle of 8 degrees at the distal end 12a, and an increase in the width of the cage 12 at the distal end 12a of approximately 29%. As noted above, the interbody fusion device 10 may also be used in TLIF fusion procedures at other spinal levels. For example, when used in a TLIF fusion procedure at the L4 / L5 level, the cage 12 may have an unexpanded height H1 of 16.0 mm and an unexpanded width W1 of 8.5 mm, corresponding to introduction via the Cambin triangle. When expanded, the distal end 12a of the cage 12 at this level increases to an expanded height H2 of 18 mm, resulting in an 8 degree lordosis angle and an expanded width W2 of 11 mm. At this other level, the cage 12 may have a 5.0 mm opening 30 at the proximal end 12b to accommodate an implant delivery device. However, other suitable diameters for the opening 30 may be used.

[0060] 16, a variation of cage 12, cage 112, is shown. Cage 112 is identical to cage 12 except that it has textured upper and lower surfaces. Because the texturing on both the upper and lower surfaces is identical, only the details of the upper textured surface are shown and described. The details of the lower textured surface are understood to be identical. A textured upper surface 34 is formed on both upper arms 16a and 16b. As shown, the textured upper surface 34 is formed on the entire upper surface 34 of upper arms 16a and 16b. In some instances, the texturing may be provided only on the portion configured to contact the vertebral end plate of the upper vertebral body adjacent the disc space. The textured surface includes the upper portions of arms 16a and 16b having fixation structures, such as a plurality of serrations 36. Such serrations 36 are not provided adjacent hinge points 18a and 18b. In other instances, the textured surface may not be formed on the distal end 12a of the cage 112 which is curved in a manner that facilitates entry of the cage 112 into the disc space.

[0061] The textured surface 34 may be formed in a three-dimensional geometric pattern having a plurality of protrusions and recesses. Such patterns may be formed by a variety of methods, including but not limited to laser ablation, acid etching, and machining. It is believed that such a patterned textured surface promotes the establishment of intimate tissue integration between the cage 112 and the endplates of the opposing vertebral bodies. In certain configurations where the cage 112 is formed from titanium, the textured surface 34 may be formed by ablating the upper and lower surfaces of the cage 112 with a pulsed laser in the nanosecond range to form a porous surface with protrusions and recesses having a depth of up to at least 100 μm. Such a process may be performed according to the nanosecond laser devices and methods taught and described, for example, in U.S. Patent No. 5,399,323, issued Dec. 5, 1995 to Singh et al., entitled "Method for Increasing the Surface Area of ​​Ceramics, Metals and Composites," the entire contents of which are incorporated herein by reference.

[0062] To further enhance the tissue integration aspect of the cage 112, the textured upper surface 34 may be post-treated by further ablating these preformed surfaces with an ultrafast pulsed laser to form additional smaller protrusions and recesses having depths of less than 1 μm and preferably 200 nm or less. Such a process may be performed using a picosecond or femtosecond pulsed laser device, such as the method and laser device taught and described in U.S. Patent No. 5,399,433, issued to Li et al., entitled "Method of Drilling Holes With Precision Laser Micromachining," October 2005, the entire contents of which are incorporated herein by reference. Other picosecond and femtosecond pulsed lasers may also be used, such as those described in U.S. Patent No. 5,399,433, issued to Lin et al., entitled "Bone Implant and Manufacturing Method Thereof," March 31, 2020, the entire contents of which are incorporated herein by reference. In one particularly preferred configuration, the textured surface 34 is formed by first laser ablating the surface of the cage 112 with a nanosecond laser device to form a porous surface, and then further modifying the surface by laser ablation with a femtosecond laser to form nanoscale structures.

[0063] While the present invention has been shown and described in detail in the drawings and the foregoing description, these should be construed as illustrative and non-limiting in nature. For example, the inventive concepts described herein may be used with expandable as well as non-expandable spinal implants, and the textured surface formed by the laser ablation process described herein may also be used with other spinal implants and in spinal surgical procedures other than TLIF applications. It is therefore to be understood that only preferred embodiments have been presented and that protection is sought for all changes, modifications, and other applications that fall within the spirit of the invention. [Explanation of symbols]

[0064] 10 Expandable Interbody Fusion Device 11 Top opening, cage top opening 12 Cage 12a Distal end 12b Proximal end 12c Longitudinal axis, midline 12d Diagonal, Corner 12e Diagonal axis 12f hollow interior, cage hollow interior, internal hollow section 13 Lower opening, bottom opening, instrument attachment mechanism 14 Base 15 Opening, cage side opening 16 Flexible movable arm 16a Upper Arm 16b Upper Arm 16c Lower Arm 16d Lower Arm 17 Opening 18a Hinge point 18b Hinge point 18c hinge point 18d hinge point 20a Inclined Cam Surface 20b Inclined cam surface 20c Inclined Cam Surface 20d Inclined Cam Surface 22a Inclined Cam Surface 22b Inclined Cam Surface 22c Inclined Cam Surface 22d Inclined Cam Surface 23a Locking notch 23b Locking notch 23c Locking notch 23d Locking notch 24 Inner graft circular opening, graft opening 26 Outer wall, cage outer wall, proximal wall 28 Inner wall 30 Inlet opening 30a Circular section 30b Arc-shaped lobe 32 Locking Pocket 32a Circular section 32b extended lobe 32c Transition Point 34 Textured top surface, Textured upper surface 36 Serrated part 100 Wedges 101 Screw hole 102 Vertical Section 102a Inclined side surface, curved side surface 102b Inclined side surface, curved side surface 102c inclined side surface 102d Sloping side surface 104 Horizontal section of the transverse axis 104a curved upper surface 104b curved upper surface 104c Curved lower surface 104d Curved lower surface 106a Engagement edge 106b Engagement edge 106c Engagement edge 106d Engagement edge 112 Cage 200 Equipment 202 Attachment end, attachment part 204 Outer tube, instrument outer tube 204a Distal end 204b Lumens 204b Internal lumen 204c Cylindrical outer surface 204d Protrusion 206 Rotatable cylindrical inner tube, inner tube, inner shaft 206a Distal end 206b Internal Lumen 206c Proximal end 206d Cylindrical outer surface 208 Rugs, Robes 210 Long and thin instrument handle 210a Handle body 210b Steering wheel cover 210c Channel 210d opening 210e Recess 211 End caps, handle end caps 211a opening 212 Wedge Driver 212a Elongated cylindrical shaft 212b Distal end 212c Proximal end 212d Threaded part 212e Extended cylindrical section 213 Keys 214 Locking Handle 214a Radial protruding shaft 214b Locking lever 214c Cam surface 214d Locking groove 214e Secondary groove, secondary groove 215 Side opening 217 Opening 218 Cam element 218a Inclined Cam Surface 220 Pocket 222 Ledge 230 Depressible locking button, depressible part 230a Depressible part, depressible button 230b Protruding lock 230c free end 230d free end 232 Compression springs, bias springs 234 Openings, handle openings 236 Drive Nut 236a Female thread 238 Conforming rectangular recess 240 Relatively flat surface, flat surface 242 Movable detent 244 Recess 246 Pivot pin 248 Opening 250 Plunger 300 Slim Cartridge 302 Pellets 304 Recess H1 Unextended device height H2 Extended height W1 Unexpanded device width W2 expansion width

Claims

1. 1. An interbody fusion device comprising:

1. A cage having a distal end, a proximal end, a base at the distal end, and a hollow interior accessible through the base, the cage comprising an instrument attachment mechanism at the base including an outer wall at the proximal end of the cage and an inner wall spaced inwardly from the outer wall and defining a locking pocket between the outer wall and the inner wall, the inner wall having a first opening and the outer wall having a second opening, the first opening and the second opening being in communication with the hollow interior of the cage, the first opening being of a smaller diameter than the second opening, and the locking pocket having a length extending behind a portion of the outer wall.

1. An interbody fixation device comprising:

2. 2. The interbody fusion device of claim 1, wherein the cage has a height and a width that intersect and define four corners of the cage, with opposite diagonal corners defining an axis that is acute angled relative to both the height and the width.

3. The interbody fusion device of claim 2 , wherein the second opening has a first, longer length along the axis and a second, shorter length transverse to the axis.

4. 4. The interbody fusion device of claim 3, wherein the second opening has a circular portion and a pair of arcuate shaped lobes extending radially from the circular portion in opposite directions along the axis, the arcuate shaped lobes defining the longer first length along the axis and the circular portion defining the shorter length.

5. 5. The interbody fusion device of claim 4, wherein the locking pocket has a circular portion aligned with the circular portion of the second opening and a pair of extending lobes extending radially from the circular portion in opposite directions along the axis, the extending lobes being in communication with the lobes of the second opening for an arcuate portion and extending beyond the lobes of the second opening to a position behind the portion of the outer wall for an additional arcuate portion.

6. 6. The interbody fixation device of claim 5, wherein the first opening defines an implant opening having a circular configuration, the height and the width of the cage define a cross-sectional area of ​​the cage, and the implant opening has an area that is greater than or equal to about 29% of the cross-sectional area of ​​the cage.

7. The interbody fusion device of claim 2 , wherein the cage is configured to be expandable.

8. The interbody fusion device of claim 7 , wherein the cage is configured to be expandable in both height and width.

9. The interbody fusion device of claim 8 , wherein the cage comprises four moveable arms hinged to the cage at the base.

10. 10. The interbody fixation device of claim 9, wherein the arms of the cage are biased outward in the height and width directions at the distal end of the cage by a wedge movable within the cage toward the distal end.

11. 11. The interbody fusion device of claim 10, wherein the cage is sized in the unexpanded state to be introduced into the intervertebral disc space in a posterolateral approach via the Cambin triangle for a transforaminal lumbar interbody fusion (TLIF) procedure.

12. The interbody fusion device of claim 1 , wherein the cage has an upper surface and an opposing lower surface, the upper and lower surfaces comprising textured surfaces.

13. 1. An interbody fusion device comprising:

1. A cage having a distal end, a proximal end, a base at the distal end, and a hollow interior accessible through the base, the cage comprising an instrument mounting mechanism at the base comprising an outer wall at the proximal end of the cage having an instrument mounting opening in communication with the hollow interior of the cage, the cage having a height and a width that intersect to define four corners of the cage, opposite diagonal corners defining an axis that forms an acute angle with both the height and the width, the instrument mounting opening having a first longer length along the axis and a second shorter length transverse to the axis.

1. An interbody fixation device comprising:

14. The interbody fusion device of claim 13 , wherein the cage is formed from titanium.

15. The interbody fusion device of claim 14 , wherein the cage has an upper surface and an opposing lower surface, the upper and lower surfaces comprising textured surfaces.

16. The interbody fusion device of claim 15 , wherein the textured surface is a laser ablated surface.

17. The interbody fusion device of claim 16 , wherein the cage is configured to be expandable.

18. The interbody fusion device of claim 17 , wherein the cage is configured to be expandable in both height and width.

19. The interbody fusion device of claim 18 , wherein the cage comprises four moveable arms hinged to the cage at the base.

20. 20. The interbody fixation device of claim 19, wherein the arms of the cage are deflectable outwardly in the height and width directions at the distal end of the cage by a wedge that is movable within the cage toward the distal end.

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