US20230013496A1

Movatterモバイル変換

Info

Publication number: US20230013496A1
Application number: US17/865,736
Authority: US
Inventors: Guntmar Eisen; Markus Salvermoser
Original assignee: Blue Ocean Spine GmbH
Current assignee: Blue Ocean Spine GmbH
Priority date: 2021-07-16
Filing date: 2022-07-15
Publication date: 2023-01-19
Also published as: US20230015512A1

Abstract

The present disclosure provides adjustable spinal devices, instruments for implanting the spinal devices, methods for adjusting the height and/or lordosis angles of the spinal devices and methods for implanting such devices. An adjustable spinal fusion device includes an upper plate having an outer surface for placement against a first vertebral body and a lower plate having an outer surface for placement against a second vertebral body. The device further includes a first translation member configured to move longitudinally relative to the upper and lower plates to adjust a distance between the upper and lower plates and a second translation member configured to move longitudinally relative to the upper and lower plates to adjust an angle between the upper and lower plates.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application Ser. Nos. 63/222,482, 63/222,498 and 63/222,506, all of which were filed Jul. 16, 2021, and European Patent Application Nos. 21186249.5, 21186250.3 and 21186251.1, all of which were filed Jul. 16, 2021, the complete disclosures of which are incorporated herein by reference in their entirety for all purposes.

FIELD

The present disclosure relates to implantable devices for stabilizing and/or promoting the fusion of adjacent bony structures and, more particularly, to implantable spinal fusion cages that can adjust in height and angle to accommodate spacing constraints and/or address lordosis within an intervertebral space.

BACKGROUND

Implantable spinal devices can be used to treat a variety of spinal disorders, including degenerative disc disease. For example, in one type of spinal disorder, the intervertebral disc has deteriorated or become damaged due to acute injury or trauma, disc disease or simply the natural aging process. The standard treatment today may involve surgical removal of a portion, or all, of the diseased or damaged intervertebral disc in a process known as a partial or total discectomy, respectively. The discectomy is often followed by the insertion of an interbody cage or spacer to stabilize this weakened or damaged spinal region and/or to restore disc height. This cage or spacer serves to reduce or inhibit mobility in the treated area, in order to avoid further progression of the damage and/or to reduce or alleviate pain caused by the damage or injury. Moreover, these types of cages or spacers serve as mechanical or structural scaffolds to restore and maintain normal disc height, and in some cases, can also provide a space for inserting bone graft material to promote bony fusion between the adjacent vertebrae.

One of the current challenges of these types of procedures is the very limited working space afforded the surgeon to manipulate and insert the cage into the intervertebral area to be treated. Access to the intervertebral space requires navigation around retracted adjacent vessels and tissues such as the aorta, vena cava, dura and nerve roots, leaving a very narrow pathway for access. The opening to the intradiscal space itself is also relatively small. Hence, there are physical limitations on the actual size of the cage that can be inserted without significantly disrupting the surrounding tissue or the vertebral bodies themselves.

Further complicating the issue is the fact that the vertebral bodies are not positioned parallel to one another in a normal spine. There is a natural curvature to the spine due to the angular relationship of the vertebral bodies relative to one another. The ideal interbody fusion cage must be able to accommodate this angular relationship of the vertebral bodies, or else the cage will not sit properly when inside the intervertebral space. An improperly fitted cage would either become dislodged or migrate out of position, and lose effectiveness over time, or worse, further damage the already weakened area.

Another challenge with implanting interbody fusion cages is that, in order to insert the cage between the adjacent vertebra, at least a portion, if not all, of the intervertebral disc is removed to make room for the cage. The removal of the entire disc or disc portion disrupts the normal lordotic or kyphotic curvature of the spine. Traditional fusion cages do not attempt to correct this curvature, and over time as the vertebrae settle around the implanted cages, kyphotic deformity results.

It is therefore desirable to provide implantable spinal devices that have the ability to maintain and restore the normal anatomy of the fused spine segment. It is particularly desirable to provide interbody cages or spacers that not only have the mechanical strength or structural integrity to restore disc height or vertebral alignment to the spinal segment to be treated, but also can easily pass through the narrow access pathway into the intervertebral space, and accommodate the angular constraints of this space and/or correct the lordotic or kyphotic curvature created by removal of the disc.

SUMMARY

The present disclosure provides adjustable spinal devices and instruments for implanting the spinal devices. The present disclosure further provides methods for adjusting the height and/or lordosis angles of the spinal devices and methods for implanting such devices.

In one aspect, an adjustable spinal fusion device includes an upper plate component having an outer surface for placement against an endplate of a vertebral body and a lower plate component having an outer surface for placement against an endplate of a vertebral body. The device further includes a first translation member configured to move longitudinally relative to the upper and lower plates to adjust a distance between the upper and lower plates (i.e., the height of the implant); and a second translation member configured to move longitudinally relative to the upper and lower plates to adjust an angle between the upper and lower plates (i.e., the angle of lordosis of the implant). Thus, the device has a first configuration for advancing through a narrow access pathway into the intervertebral space, and a second configuration, wherein the device may be adjusted in height and/or angle to accommodate the angular constraints of this space and/or correct the lordotic or kyphotic curvature.

In embodiments, the first and second translation members are coupled to each other such that longitudinal movement of the first translation member causes longitudinal movement of the second translation member to adjust both the distance and angle between the upper and lower endplates.

In embodiments, the first translation member includes a first movable wedge having at least one angled surface. The upper and lower endplates each comprise a ramp for cooperating with the angled surface of the first movable wedge such that longitudinal movement of the first movable wedge adjusts a distance between at least a proximal portion of the upper and lower endplates. In one such embodiment, the upper and lower endplates each comprise first and second ramps extending towards each other in the proximal direction and the movable wedge comprises first and second upper angled surfaces for cooperating with the first and second ramps of the upper endplate and first and second upper angled surfaces for cooperating with the first and second ramps of the lower endplate.

In embodiments, longitudinal movement of the second translation member relative to the first translation member adjusts the angle between the upper and lower endplates. This allows for independent adjustment of the devices height and angle after it has been implanted between the vertebral bodies. The second translation member may include a second movable wedge with at least one angled surface. The upper and lower endplates may each comprise a ramp for cooperating with the angled surface of the second movable wedge of the second translation member such that longitudinal movement of the second movable wedge adjusts a distance between at least a distal portion of the upper and lower endplates.

The ramps on the upper and lower endplates may be located on the proximal and distal portions of the endplates. In certain embodiments, this allows the first movable wedge to cooperate with these ramps to move the upper and lower endplates such that they remain substantially parallel to each other (i.e., adjustment in height). In other embodiments, the first moveable wedge cooperates with the proximal endplate ramps and the second moveable wedge cooperates with the distal endplate ramps.

The device may further comprise a first rotatable shaft coupled to the first translation member for moving the first translation member in the longitudinal direction and a second rotatable shaft for moving the second translation member in the longitudinal direction. In embodiments, the first and second rotatable shafts each comprise a proximal mating feature configured for mating to an instrument such that rotation of the actuator shafts causes longitudinal movement of the translation members.

In embodiments, the first translation member comprises at least one projection, such as a pin, extending laterally away from the longitudinal axis and at least one of the upper and lower endplates comprises an opening or slot for receiving the projection. The projection(s) are configured to slide within the slot(s) to stabilize the upper and lower endplates during longitudinal movement of the first translation member. The second translation member may further comprise at least one guide arm that cooperates with at least one guide rail on the upper endplate to stabilize the upper and lower endplates during longitudinal movement of the second translation member. In embodiments, the projections and the guide arm also serve to couple the first and second translation members to the upper and lower endplates.

In embodiments, the device further comprises a stabilization plate coupled to the first rotatable shaft such that the stabilization plate remains fixed in place relative to the upper and lower endplates as the first and second translation members are moved in the longitudinal direction. The stabilization plate may comprise a hinge biased inwards towards the longitudinal axis of the device for securing the stabilization plate to the first rotatable shaft.

In certain embodiments, the stabilization plate further includes one or more projections that define a central channel extending distally towards the translation members. The first translation member comprises at least one vertical projection extending into the central channel to stabilize lateral movement of the first translation member as it is moved longitudinally relative to the endplates. The projections may also form a U-shape that provides a proximal backstop to inhibit the first translation member from advancing too far in the proximal direction. The stabilization plate may further include one or more projections or knobs extending laterally outward and at least one of the upper and lower endplates may comprise one or more internal slot(s) for receiving these knobs to stabilize the upper and lower endplates as the translation members are moved longitudinally.

In another aspect, a spinal fusion system comprises an adjustable spinal fusion device having an upper endplate with an outer surface for placement against a first vertebral body and a lower endplate with an outer surface for placement against a second vertebral body. The device includes a first translation member configured to move longitudinally relative to the upper and lower plates to adjust a distance between the upper and lower plates and a second translation member configured to move longitudinally relative to the upper and lower plates to adjust an angle between the upper and lower plates. The system further comprises an instrument having a proximal handle, an elongate shaft and an actuator within the elongate shaft coupled to the proximal handle for moving the first and second translation members longitudinally relative to the upper and lower endplates.

In embodiments, the actuator comprises a first rotatable actuator coupled to the first translation member and a second rotatable actuator coupled the second translation member. The second rotatable actuator may extend through an inner lumen in the first rotatable actuator.

In embodiments, rotation of the first actuator causes longitudinal movement of the first translation member and the second translation member to adjust the distance and angle between the upper and lower endplates. In embodiments, rotation of the second actuator causes longitudinal movement of the second translation member relative to the first translation member to adjust the angle between the upper and lower endplates.

In embodiments, the device further comprises a stabilization plate coupled to the first rotatable actuator such that the stabilization plate remains fixed in place relative to the upper and lower endplates as the first and second translation members are moved in the longitudinal direction. The instrument may comprise first and second gripping arms configured for coupling to the stabilization plate.

In embodiments, the stabilization plate comprises a hinge biased inwards towards the longitudinal axis of the device for securing the stabilization plate to the first rotatable shaft. The stabilization plate may include a projection defining a central channel and the first translation member comprises at least one vertical projection extending into the central channel, wherein the central channel stabilizes lateral movement of the first translation member. The stabilization plate may include one or more knobs extending laterally from the stabilization plate and at least one of the upper and lower endplates comprises an internal slot for receiving the at least one or more knobs to stabilize the upper and lower endplates as the first translation member is moved longitudinally.

In another aspect, an adjustable spinal fusion device comprises an upper endplate having an outer surface for placement against a first vertebral body and a lower endplate having an outer surface for placement against a second vertebral body. The lower endplate is a separate component from the upper endplate. The device further includes a translation member configured to move longitudinally relative to the upper and lower endplates to adjust a distance between at least a portion the upper and lower endplates. The translation member comprises one or more projections extending laterally from the translation member. At least one of the endplates comprises one or more slots for receiving the projection(s) to couple the upper endplate to the lower endplate.

In embodiments, the device further comprises a second translation member configured to move longitudinally relative to the upper and e lower plates to adjust an angle between the upper and lower endplates. The second translation member comprises one or more projections extending laterally from the second translation member. At least one of the endplates comprises one or more slots for receiving the projections to couple the upper endplate to the lower endplate

In embodiments, the device further comprises a stabilization plate that is a separate component as the upper and lower endplates and the translation member. The stabilization plate comprises one or more projections and at least one of the upper and lower endplates comprises one or more slots for receiving the one or more projections and coupling the stabilization member to the upper and lower endplates. The stabilization plate may also include a projection defining a central channel and the first translation member comprises at least one vertical projection extending into the central channel to couple the first translation member to the stabilization plate.

In embodiments, the device is fabricated through additive manufacturing techniques, such as 3D printing. The implant may be formed layer by layer in the longitudinal direction from the proximal end to the distal end. Upon completion of manufacturing, the upper and lower endplates are separated from each other and remain together during use by (1) the projections in the first translation member that slide through openings or slots in the endplates; and/or (2) the projections in the stabilization plate that slide through openings or slots in the endplates; and/or (3) the projections on the second translation member that move along the ramps in the endplates; and/or (4) the projections in the first translation member that slide through the central channel in the stabilization plate.

In embodiments, at least one of the upper and lower endplates comprises a surface with one or more exhaust openings for extracting metal powder from within the device. This allows more efficient extraction of metal powder that may, for example, remain in the cage after 3D printing.

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

BRIEF DESCRIPTION OF THE DRAWINGS

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

FIG.1 is a partially transparent view of a spinal fusion device with a lordosis angle;

FIG.2 is a perspective view of the spinal fusion device ofFIG.1 in a configuration for delivery between adjacent vertebral bodies;

FIG.3 is an exploded view of the spinal fusion device ofFIG.1;

FIG.4 is a perspective view of a lower endplate of the spinal fusion device ofFIG.1;

FIG.5 is a perspective view of an upper endplate of the spinal fusion device ofFIG.1;

FIG.6A is a perspective view of a proximal translation member of the spinal fusion device ofFIG.1;

FIG.6B is a side view of the proximal translation member ofFIG.6A;

FIG.7 is a partial cross-sectional view of one portion of the proximal translation member ofFIG.6A;

FIG.8 is a perspective view of a proximal rotatable shaft actuator of the spinal fusion device ofFIG.1;

FIG.9 is a perspective view of a stabilization plate of the spinal fusion device ofFIG.1:

FIG.10A is a perspective view of a distal rotatable actuator of the spinal fusion device ofFIG.1;

FIG.10B is a perspective view of a distal translation member of the spinal fusion device ofFIG.1;

FIG.11A illustrates the distal translation member coupled to the distal rotatable actuator;

FIG.11B illustrates the stabilization plate coupled to the proximal rotatable actuator;

FIG.12 is a partial cross-sectional view of the spinal fusion device, illustrating internal threads of the proximal translation member;

FIG.13 is a perspective view of an instrument for inserting the spinal fusion device ofFIG.1 between adjacent vertebral bodies in a patient; and

FIG.14 is an exploded view of the instrument ofFIG.1313 attached to the spinal fusion device;

FIG.15 is a partially exploded side view of a distal portion of the instrument and the spinal fusion device;

FIG.16 illustrates inner and outer rotatable shafts of the instrument ofFIG.12;

FIG.17A illustrates the spinal fusion device in a configuration for insertion between adjacent vertebral bodies;

FIG.17B illustrates the spinal fusion device with a height adjustment that increases the distance between the upper and lower endplates; and

FIG.17C illustrates the spinal fusion device with an angle adjustment that increases the distance between distal portions of the upper and lower endplates.

DESCRIPTION OF THE EMBODIMENTS

This description and the accompanying drawings illustrate exemplary embodiments and should not be taken as limiting, with the claims defining the scope of the present disclosure, including equivalents. Various mechanical, compositional, structural, and operational changes may be made without departing from the scope of this description and the claims, including equivalents. In some instances, well-known structures and techniques have not been shown or described in detail so as not to obscure the disclosure. Like numbers in two or more figures represent the same or similar elements. Furthermore, elements and their associated aspects that are described in detail with reference to one embodiment may, whenever practical, be included in other embodiments in which they are not specifically shown or described. For example, if an element is described in detail with reference to one embodiment and is not described with reference to a second embodiment, the element may nevertheless be claimed as included in the second embodiment. Moreover, the depictions herein are for illustrative purposes only and do not necessarily reflect the actual shape, size, or dimensions of the system or illustrated components.

It is noted that, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the,” and any singular use of any word, include plural referents unless expressly and unequivocally limited to one referent. As used herein, the term “include” and its grammatical variants are intended to be non-limiting, such that recitation of items in a list is not to the exclusion of other like items that can be substituted or added to the listed items.

Referring now toFIGS.1-3, aspinal implant10 according to the present disclosure is configured for placement between two adjacent vertebral bodies. In some embodiments,implant10 is particularly useful for placement from a posterior approach outside of the facet joint (transforaminal lumbar interbody fusion or TLIF), although it will be recognized that the implants disclosed herein may be employed in a variety of different surgical approaches, such as anterior lumbar interbody fusion (ALIF), posterior lumbar interbody fusion (PLIF) and/or lateral lumbar interbody fusion (LLIF).

Implant

10 includes upper and

lower endplates

12,14, adistal translation member16, aproximal translation member18, and aproximal stabilization plate20. Theimplant10 further includes distal and

proximal shaft actuators

22,24 for longitudinally translating the distal and

proximal translation members

16,18, respectively, relative to the

endplates

12,14. Movement of the

translation members

16,18 in substantially the longitudinal direction changes the height and angle of the

endplates

12,14, as discussed in more detail below.

As shown inFIGS.2,4 and5, the upper and

lower endplates

12,14 each include an

outer surface

26,28 for contacting the surface of a vertebral body. The outer surfaces are preferably roughened with a surface treatment that facilitates attachment to the vertebral body. The surface treatment preferably creates a diamond structure (e.g., diamond 20-1.5), although other patterns are contemplated. The upper and

lower endplates

12,14 also preferably include

central openings

30,32 that extend through the

entire endplates

12,14 and, in one embodiment, are substantially aligned with each other. Similarly, theproximal translation member18 includes a central opening or bore34 that, in one embodiment, may be substantially aligned with theendplate openings30,32 (seeFIG.6A). These openings create space for the addition of bone graft or other substances into the implant, as well as to allow for bony ingrowth through theimplant10.

Theupper endplate12 includes: (1) first and second distal sloped surfaces or

ramps

40,42 that are laterally spaced from each other near either side of the upper endplate and extend towards thelower plate14 in the proximal direction; and (2) third and fourth proximal sloped surfaces or

ramps

44,46 that are laterally spaced from each other near either side of the endplate and also extend towards thelower endplate14 in the proximal direction. Thelower endplate14 includes: (1) first and second distal sloped surfaces or

ramps

50,52 laterally spaced from each other extending upwards towards theupper endplate12 in the proximal direction; and (2) third and fourth proximal sloped surfaces or

ramps

54,56 that are laterally spaced from each other near either side of the endplate and also extend upwards towards theupper endplate12 in the proximal direction. These ramps interact with wedges on the translation members to provide height and angular adjustment of the implant.

In an alternative embodiment,upper endplate12 may include a single distal ramp and/or a single proximal ramp that extends laterally across a central portion of theendplate12. Alternatively,endplate12 may include more than two distal or proximal ramps.

The upper and

lower endplates

12,14 each further include a proximal cut-

out

60,62 for receiving upper and lower portions ofstabilization plate20, and vertical knobs or

projections

64,66 extending from the proximal translation member18 (seeFIGS.6A and6B).

As shown inFIGS.10B and11A,distal translation member16 has amain body70 positioned near the distal end of

endplates

12,14 and forming a distal portion ofimplant10.Main body70 includes acentral bore72 for receivingdistal shaft actuator22 and first and second

lateral portions

74,76 extending laterally outward fromcentral bore72.

Lateral portions

74,76 each further include: (1) first and second upper sloped surfaces or

wedges

80,82 laterally spaced from each other and extending downwards towardslower endplate14 in the proximal direction; and (2) first and second lower sloped surfaces or

wedges

84,86 laterally spaced from each other and extending upwards towardsupper endplate12 in the proximal direction.

Upper wedges

80,82 are configured to contact and engage upper endplate

distal ramps

40,42, and

lower wedges

84,86 are configured to contact and engage lower endplate

distal ramps

50,52 such that movement ofdistal translation member16 in the proximal direction causes the proximal ends of

endplates

12,14 to move apart from each other. This movement may cause an adjustment in height and/or angle, as discussed below.

In an alternative embodiment,distal translation member16 may include a single distal ramp and/or a single proximal ramp that extends laterally across a central portion of thetranslation member16. Alternatively,translation member16 may include more than two distal or proximal ramps.

Lateral portions

74,76 ofdistal translation member16 also include

outer guide arms

90,92 that engage with openings, slots or

grooves

94,96 on the outer surfaces of the distal ramps on upper endplate12 (seeFIG.5) to stabilize the endplates during height and angle adjustment. Specifically, these

outer guide arms

90,92 comprise substantially

vertical rails

98,100 on either side ofdistal translation member16 that include

projections

102,104 designed to engage

grooves

94,96 of the upper distal endplate ramp and to ride along these ramps asdistal translation member16 is moved in the longitudinal direction.

Referring now toFIG.10A,distal actuator shaft22 includes a distal endplate or bolt110, a threadedshaft112 and a proximal mating feature, such as a shaped opening like, for example, ahexalobe114, for mating with an instrument (discussed below). In certain embodiments,distal actuator shaft22 is secured to thedistal translation member16 with a flexible hinge orprong116 that is biased inwards towards the longitudinal axis of the implant to secureactuator shaft22 todistal translation member16. Threadedshaft112 also extends through adistal opening124 inproximal translation member18 for mating with an instrument (discussed below).

As shown inFIGS.6A,6B and7,proximal translation member18 includes a substantially cylindricalmain body120 that extends through a portion of the implant between

endplates

12,14.Main body120 has a centrallongitudinal bore122 for receiving proximal and

distal actuator shafts

22,24 and acentral opening34 extending from an upper surface through to the lower surface for receiving graft material and for allowing bony ingrowth therethrough.Proximal translation member18 includes first and second upper sloped surfaces or

wedges

130,132 that are configured to contact and engage first and second

proximal ramps

44,46 ofupper endplate12, and first and second lower surfaces or

wedges

134,136 that are configured to contact and engage first and second

proximal ramps

54,56 of the lower endplate14 (alternatively,translation member18 may comprise a single ramp or more than two ramps, as discussed above). Longitudinal movement ofproximal translation member18 causes these wedges to move along the ramps of the endplates, thereby moving the proximal ends of the endplates either towards or away from each other.

As shown inFIG.7,proximal translation member18 further includes distalinternal threads140 that rotatably mate with threadedshaft112 of distal actuator shaft22 (seeFIG.12). Rotation of this threadedshaft112 causesdistal translation member16 to move longitudinally relative toproximal translation member18 and

end plates

12,14 for angle adjustment, as discussed below.Proximal translation member18 also includes proximalinternal threads138 that are rotatably mated with a threadedshaft150 ofproximal actuator24. Rotation ofproximal actuator24 causes proximal translation member18 (and thedistal translation member16 therewith) to move longitudinally relative to

endplates

12,14 for height adjustment.

Proximal translation member

18 further includes one ormore projections142 extending laterally away from the translation member.Projections142 may, for example, comprise pins having a tapered end extending away frommember18. These tapered orconical pins142 extend through angled slots144 (seeFIG.1) in upper and

lower endplates

12,14 and serve to stabilize the endplates during height and angle adjustment. In particular,proximal translation member18 includes at least twoconical pins142 on each side, with one of the lateral pins on each side riding throughslots144 on the upper endplate and the other lateral pin riding throughslots144 on the lower endplate astranslation member18 is moved longitudinally relative to the endplates.

As shown inFIGS.9 and11B,stabilization plate20 includes acentral opening160 for receiving a portion ofproximal actuator shaft24.Proximal actuator shaft24 includes aproximal bolt152 that is secured tostabilization plate20 with a hinge, spring or prong162 on thestabilization plate20 that is biased inwards towards the longitudinal axis.Bolt152 includes amating feature154 for engaging with a similar mating feature on an instrument (discussed below).Proximal actuator24 further includes acentral bore156 for receiving an instrument to mate withdistal actuator shaft22, as discussed below.

Stabilization plate

20 is secured toproximal actuator shaft24 such that it remains fixed in place relative to

endplates

12,14 as the translation members are moved in the longitudinal direction.Plate20 includes two

longitudinal projections

164,166 on both of its upper and lower surfaces that extend towards the endplates to form a U-shaped projection with acentral channel168.Proximal translation member18 includes upper and lower

vertical projections

64,66 configured to extend into thesechannels168 and to move through thechannels168 asproximal translation member18 moves in the longitudinal direction. The

U-shaped projections

164,166 andchannels168 serve to stabilize the endplates and prevent seesaw or lateral movement ofproximal translation member18. In addition, these

U-shaped channels

164,166 serve as a backstop to prevent excessive movement of theproximal translation member18 in the proximal direction.

In addition,stabilization plate20 may further includeprojections170 extending laterally from the longitudinal projections.Projections170 may, for example, include tapered or conical-shaped knobs. In an exemplary embodiment,plate20 includes two such knobs on each side for a total of four conical knobs. These knobs are configured to slide withininternal slots172 on the upper and lower endplates to further stabilize the implant during height adjustment (seeFIGS.4 and5).

Stabilization plate

20 may further includelateral projections174 on either side of the plate that create two lateral grooves or

channels

178,180 for mating with a gripping arm of an insertion instrument (discussed below).

Referring now toFIGS.13-16,insertion instrument200 comprises anelongated shaft202 with aproximal handle204 and a distalgripping element206 for removably coupling to implant10. Distalgripping element206 preferably includes first and second

gripping arms

208,210 for coupling tostabilization plate20, i.e., to the lateral channels or

grooves

178,180 created bylateral projections174,176 on the stabilization plate (e.g., a bayonet style connection). Distal

gripping arms

208,210 are coupled to anactuator212 on theproximal handle204 to move the

arms

208,210 in a substantially lateral direction relative to the longitudinal axis of theshaft202. The

arms

208,210 can be moved together to hold the lower endplate and moved apart to release the endplate.

An innerrotatable shaft220 extends from thehandle204 to thedistal actuator22 and an outerrotatable shaft222 extends from thehandle204 to theproximal actuator24. Inner and

outer shafts

220,222 are both attached to

rotatable knobs

224,226, respectively, on the proximal handle for rotating

shafts

220,222 and thereby rotating proximal and

distal actuators

22,24. Alternatively,

shafts

220,222 may be configured to move longitudinally (i.e., rather than rotate) to move the translation members.

Handle204 includes markings or

indicia

230,232 to correlate rotation of the shafts with height and angle adjustment of the endplates.Inner shaft220 has afemale mating feature234 that may be coupled to the male mating feature of the distal actuator (i.e., the hexalobe114) and theouter shaft222 has afemale mating feature236 that can be coupled to thebolt152 on theproximal actuator24.

Handle204 further includes a thirdrotatable knob240 coupled to theshaft202 for rotating theshaft202 and theendplate10 therewith relative to the handle. This allows for rotation of the endplate without rotating the handle to facilitate ease of use during implantation.

In use,implant10 may be advanced into an intervertebral space in a collapsed configuration (see the resting state shown inFIG.17A). To increase the height of the implant, endplates12,14 are moved away from each other in a substantially parallel direction. To that end,rotatable knob226 onhandle204 is rotated to thereby rotateouter shaft222 ofinsertion instrument200. This rotation causesproximal actuator24 to rotate, thereby causing its threadedshaft150 to rotate within proximalinternal threads138 ofproximal translation member18. This translates both proximal and

distal translation members

16,18 in the proximal direction. Asdistal translation member16 moves in proximal direction, its

upper wedges

80,82 engage with upper endplate

distal ramps

40,42 and its

lower wedges

84,86 engage with the lower endplate

distal ramps

50,52 such that the distal ends of the endplates move apart from each other. At the same time, the

wedges

130,132,134,136 of theproximal translation member18 engage the

proximal ramps

44,46,54,56 of the endplates to move the proximal ends of the endplates away from each other. This causes the endplates to move away from each other in a substantially parallel direction (see expanded state shown inFIG.17B).

To adjust the angle of the endplates,rotatable knob224 onhandle204 is rotated, causinginner shaft234 to rotate. This rotation is translated to hexalobe114 ondistal actuator22. Asdistal actuator22 rotates,distal translation member16 is translated in a proximal direction relative to both

endplates

12,14 andproximal translation member18. Sinceproximal translation member18 does not move, the proximal ends of the endplates remain fixed relative to each other. The upper and lower wedges of the distal translation member contact and engage the upper and lower distal ramps of the endplates, causing the distal ends of the endplates to move apart from each other, thereby adjusting the angle of the upper endplate relative to the lower endplate (the angularly adjusted state shown inFIG.17C).

The process of height and angle adjustment may be reversible and may also be stepless, i.e., a continuous adjustment without discrete steps. Alternatively, the height and angle adjustment may be based on a series of discrete steps which correlate to discrete distances and angles of the endplates. The height and angle may be adjusted independently of each other. For example, the above process can be reversed such that the inner shaft is first rotated to adjust the angle, and then the outer shaft is rotated to adjust height.

In certain embodiments, theentire implant10 is fabricated through additive manufacturing techniques, such as 3D printing or the like. The implant may be formed layer by layer in the longitudinal direction from the proximal end to the distal end. Upon completion of manufacturing, the upper and lower endplates are separated from each other. The endplates remain together during use by: (1) the knobs in the proximal translation member that slide through slots in the endplates; (2) the knobs in the stabilization plate that slide through slots in the endplates; (3) the side projections on the distal translation member that slide along the proximal ramps in the endplates; and (4) the upper and lower knobs in the proximal translation member that slide through the U-shaped channel in the stabilization plate.

In an exemplary embodiment, the implants are produced by Selective Laser Melting (SLM). For example, a substrate plate is fastened to an indexing table inside a chamber with a controlled atmosphere of inert gas (e.g., argon or nitrogen). Metal powder is applied flat to the substrate plate as a layer. The metal powder is preferably a titanium alloy, e.g., Ti-6Al-4V to enable biocompatibility. Each 2D slice of the cage is fused by selectively melting the metal powder via a laser. The laser has enough energy to fully melt or rather weld the metal particles to form solid metal. The substrate plate is lowered by the layer thickness (z-direction). New metal powder is applied and the process is repeated layer by layer until the part is complete. The completed part is removed from the substrate plate by cutting or breaking off.

Preferably, all components of the cage are printed nested within each other. Compared to separately 3D printing all components next to each other, a higher utilization rate can be achieved. This means that during 3D printing, a higher proportion which is melted and a lower proportion which stays as metal powder can be achieved. Thus, production time and costs can be reduced significantly.

After 3D printing, areas connecting single components of the cage are cut by electrical discharge machining (EDM) to enable their separate movement. Further, EDM can be used to realize smooth surfaces, e.g., to enable low-friction sliding of two components against each other. With EDM, the cage can also be removed from the substrate plate.

To lower production costs, several cages can be printed onto one substrate plate.

The implant may comprise one or more exhaust openings in the upper and lower endplates to allow for extraction of the metal powder remaining in the cage after 3D printing. Preferably, the exhaust opening is positioned on a lateral surface of the moving plate). It is also possible to position the exhaust opening on a horizontal surface of the cage, preferably on the base plate or on the moving plate. Preferably, the cage comprises multiple exhaust openings. Thus, more areas inside the cage are reachable and the metal powder can be extracted more efficiently. It is also possible to configure an external sliding mean, preferably a conical groove, in such a way that it can be additionally used as an exhaust opening. Therefore, the conical groove is deepened until a passage to the outside has been made.

Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the embodiment disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the embodiment being indicated by the following claims.

Claims

What is claimed is:

1. An adjustable spinal fusion device, comprising:

an upper endplate having an outer surface for placement against a first vertebral body;

a lower endplate having an outer surface for placement against a second vertebral body;

a first translation member configured to move longitudinally relative to the upper and lower endplates to adjust a distance between the upper and lower endplates; and

a second translation member configured to move longitudinally relative to the upper and lower plates to adjust an angle between the upper and lower endplates.

2. The adjustable spinal fusion device ofclaim 1, wherein longitudinal movement of the first translation member causes longitudinal movement of the second translation member to adjust the distance and angle between the upper and lower endplates.

3. The adjustable spinal fusion device ofclaim 1, wherein longitudinal movement of the second translation member relative to the first translation member adjusts the angle between the upper and lower endplates.

4. The adjustable spinal fusion device ofclaim 1, further comprising a first rotatable shaft coupled to the first translation member for moving the first translation member in the longitudinal direction and a second rotatable shaft coupled to the second translation member for moving the second translation member in the longitudinal direction.

5. The adjustable spinal fusion device ofclaim 4, wherein the first translation member includes a first movable wedge having at least one angled surface and wherein the upper and lower endplates each comprise a ramp for cooperating with the angled surface of the first movable wedge such that longitudinal movement of the first movable wedge adjusts a distance between at least a proximal portion of the upper and lower endplates.

6. The adjustable spinal fusion device ofclaim 5, wherein the upper and lower endplates each comprise first and second ramps extending towards each other in the proximal direction, wherein the first movable wedge comprises first and second upper angled surfaces for cooperating with the first and second ramps of the upper endplate and first and second upper angled surfaces for cooperating with the first and second ramps of the lower endplate.

7. The adjustable spinal fusion device ofclaim 1, wherein the first translation member comprises at least one projection extending laterally away from the first translation member and at least one of the upper and lower endplates comprises an angled slot for receiving the projection to stabilize the upper and lower endplates during longitudinal movement of the first translation member.

8. The adjustable spinal fusion device ofclaim 5, wherein the second translation member includes a second movable wedge with at least one angled surface and wherein the upper and lower endplates each comprise a ramp for cooperating with the angled surface of the second movable wedge of the second translation member such that longitudinal movement of the second movable wedge adjusts a distance between at least a distal portion of the upper and lower endplates.

9. The adjustable spinal fusion device ofclaim 8, wherein the upper and lower endplates each comprise first and second ramps extending towards each other in the proximal direction, wherein the second movable wedge comprises first and second upper angled surfaces for cooperating with the first and second ramps of the upper endplate and first and second upper angled surfaces for cooperating with the first and second ramps of the lower endplate.

10. The adjustable spinal fusion device ofclaim 1, wherein the second translation member comprises at least one guide arm that cooperates with at least one guide rail on the upper endplate to stabilize the upper and lower endplates during longitudinal movement of the second translation member.

11. The adjustable spinal fusion device ofclaim 4, further comprising a stabilization plate coupled to the first rotatable shaft such that the stabilization plate remains fixed in place relative to the upper and lower endplates as the first and second translation members are moved in the longitudinal direction.

12. The adjustable spinal fusion device ofclaim 11, wherein the stabilization plate includes a projection defining a central channel and the first translation member comprises at least one vertical projection extending into the central channel, wherein the central channel stabilizes lateral movement of the first translation member.

13. The adjustable spinal fusion device ofclaim 11, wherein the stabilization plate includes one or more knobs extending laterally from the stabilization plate and at least one of the upper and lower endplates comprises an internal slot for receiving the at least one or more knobs to stabilize the upper and lower endplates as the first translation member is moved longitudinally.

14. A spinal fusion system, comprising:

an adjustable spinal fusion device comprising:

an upper plate component having an outer surface for placement against an endplate of a vertebral body;

a lower plate component having an outer surface for placement against an endplate of a vertebral body; and

a movable wedge configured to move longitudinally relative to the upper and lower plates to adjust a distance and an angle between the upper and lower plates; and

an instrument having a proximal handle, an elongate shaft and an actuator within the elongate shaft coupled to the proximal handle and the movable wedge for translating the movable wedge longitudinally relative to the upper and lower endplates.

15. The system ofclaim 14, wherein the movable wedge comprises a first movable wedge, the system further comprising a second movable wedge, wherein the actuator comprises a first rotatable shaft coupled to the proximal handle the first movable wedge and a second rotatable shaft coupled to the proximal handle the second movable wedge.

16. The system ofclaim 14, further comprising a stabilization plate coupled to the first rotatable shaft such that the stabilization plate remains fixed in place relative to the upper and lower endplates as the first and second movable wedges are moved in the longitudinal direction, wherein the instrument further comprising first and second gripping arms configured for coupling to the stabilization plate.

17. An adjustable spinal fusion device, comprising:

a lower endplate having an outer surface for placement against a second vertebral body, wherein the lower endplate is a separate component from the upper endplate;

a translation member configured to move longitudinally relative to the upper and lower endplates to adjust a distance between at least a portion the upper and lower endplates; and

wherein the translation member comprises one or more projections extending laterally from the translation member and wherein at least one of the endplates comprises one or more slots for receiving the projections to couple the upper endplate to the lower endplate.

18. The spinal fusion device ofclaim 17, wherein the translation member is a first translation member for adjusting the distance between the upper and lower endplates, the device further comprising a second translation member configured to move longitudinally relative to the upper and e lower plates to adjust an angle between the upper and lower endplates.

19. The spinal fusion device ofclaim 18, wherein the second translation member comprises one or more projections extending laterally from the second translation member and wherein at least one of the endplates comprises one or more slots for receiving the projections to couple the upper endplate to the lower endplate

20. The spinal fusion device ofclaim 17, further comprising a stabilization plate that is a separate component as the upper and lower endplates and the translation member, wherein the stabilization plate comprises one or more projections and at least one of the upper and lower endplates comprises one or more slots for receiving the one or more projections and coupling the stabilization member to the upper and lower endplates.

21. The spinal fusion device ofclaim 20, wherein the stabilization plate includes a projection defining a central channel and the first translation member comprises at least one vertical projection extending into the central channel to couple the first translation member to the stabilization plate.

22. The spinal fusion device ofclaim 17, wherein at least one of the upper and lower endplates comprises a surface with one or more exhaust openings for extracting metal powder from within the device.