# US 2021/0275319 A1 · Expandable Interbodies and Related Methods

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- Number: US 2021/0275319 A1
- Document ID: US20210275319A1
- Status: Published application
- Kind: A1
- Application number: 17/190,798
- Filed: 2021-03-03
- Published: 2021-09-09
- Earliest claimed: 2020-03-05
- Assignees: Alphatec Spine, Inc.
- Applicants: Alphatec Spine, Inc.
- Inventors: William Reimels
- Web page: https://patentgrep.com/patent/US20210275319A1

## CPC

- A61F 2/447: {substantially parallelepipedal, e.g. having a rectangular or trapezoidal cross-section}
- A61F 2/4455: {for the fusion of spinal bodies, e.g. intervertebral fusion of adjacent spinal bodies, e.g. fusion cages (intervertebral discs A61F2/442)}
- A61F 2/4611: {of spinal prostheses}
- A61F 2002/30156: {triangular}
- A61F 2002/30224: {cylindrical}
- A61F 2002/30331: {made by longitudinally pushing a protrusion into a complementarily-shaped recess, e.g. held by friction fit}
- A61F 2002/30383: {made by laterally inserting a protrusion, e.g. a rib into a complementarily-shaped groove}
- A61F 2002/30405: {made by screwing complementary threads machined on the parts themselves}
- A61F 2002/30433: {using additional screws, bolts, dowels, rivets or washers e.g. connecting screws}
- A61F 2002/30471: {connected by a hinged linkage mechanism, e.g. of the single-bar or multi-bar linkage type}
- A61F 2002/30476: {locked by an additional locking mechanism}
- A61F 2002/30507: {using a threaded locking member, e.g. a locking screw or a set screw}
- A61F 2002/30537: {adjustable}
- A61F 2002/3054: {about a connection axis or implantation axis for selecting any one of a plurality of radial orientations between two modular parts, e.g. Morse taper connections, at discrete positions, angular positions or continuous positions}
- A61F 2002/30556: {for adjusting thickness}
- A61F 2002/30579: {with mechanically expandable devices, e.g. fixation devices}
- A61F 2002/30784: {Plurality of holes}
- A61F 2002/30827: {Plurality of grooves}
- A61F 2002/30828: {parallel}
- A61F 2002/30971: {Laminates, i.e. layered products}
- A61F 2002/4627: {with linear motion along or rotating motion about the instrument axis or the implantation direction, e.g. telescopic, along a guiding rod, screwing inside the instrument}
- A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C)

## Abstract

The present disclosure relates to expandable interbodies that include superior and inferior shells and a control assembly positioned between and inside of the shells, the control assembly including nested cages operably connected to each other with an adjustment screw. Rotation of the adjustment screw translates the cages relative to each other, which in turn causes the shells to open or expand.

## Claims

### Claim 1

An expandable interbody comprising:
a superior shell having a proximal end and a distal end, the superior shell defining a superior surface extending from the proximal end to the distal end configured to engage an inferior surface of a first vertebral body, the superior shell having two side walls, at least one wall having at least one angled channel;
an inferior shell having a proximal end and a distal end, the inferior shell defining an inferior surface configured to engage a superior surface of a second vertebral body, the inferior shell having two side walls, at least one wall having at least one angled channel; and
a control member comprising interlocking proximal and distal cages and an adjustment screw defining a longitudinal axis, the adjustment screw configured to engage with the proximal and distal cages;
wherein the proximal cage comprises at least one superior lateral projection and at least one inferior lateral projection, each lateral projection configured to engage with one of the at least one angled channel of the superior and inferior shells;
wherein the distal cage comprises a at least one superior lateral projection and at least one inferior lateral projection, each lateral projection configured to engage with one of the at least one angled channel of the superior and inferior shells,
wherein rotation of the adjustment screw causes the distal cage to move longitudinally relative to the proximal cage, which in turn causes the interbody to expand or contract in a direction transverse to the longitudinal axis.

### Claim 2 (depends on 1)

The expandable interbody of claim 1, wherein the superior and inferior shells each further comprise distal and proximal angled surfaces, wherein the distal and proximal cages each further comprise superior and inferior angled surfaces that engage with the angled surfaces of the superior and inferior shells.

### Claim 3 (depends on 2)

The expandable interbody of claim 2, wherein at least one of the angled surfaces of the proximal and distal cages defines a rounded surface or cylindrical-shaped surface so as to achieve a linear point of contact between it and the corresponding angled surface of the superior and/or inferior shell.

### Claim 4 (depends on 3)

The expandable interbody of claim 3, wherein the cylindrical-shaped surface comprises a pin.

### Claim 5 (depends on 4)

The expandable interbody of claim 4, wherein the pin comprises a material distinct from that of the cage to which it is secured.

### Claim 6 (depends on 5)

The expandable interbody of claim 5, wherein the material of the pin is selected to achieve a lower coefficient of friction between it and the ramps of the superior and/or inferior shells than would be achieved if the material of the pin were identical to that of the cage.

### Claim 7 (depends on 1)

The expandable interbody of claim 1, wherein one or more of the lateral projections comprises a pin secured to the proximal and/or distal cage, at least one end of the pin is configured to slide along the appropriate angled channel.

### Claim 8 (depends on 7)

The expandable interbody of claim 7, wherein the pin comprises a material distinct from that of the cage to which it is secured.

### Claim 9 (depends on 8)

The expandable interbody of claim 8, wherein the material of the pin is selected to achieve a lower coefficient of friction between it and the channels of the superior and/or inferior shells than would be achieved if the material of the pin were identical to that of the cage.

### Claim 10 (depends on 1)

The expandable interbody of claim 1, wherein the adjustment screw threadingly engages with the distal cage and is in a fixed longitudinal orientation relative to the proximal cage.

### Claim 11 (depends on 1)

The expandable interbody of claim 1, wherein the adjustment screw threadingly engages with the proximal cage and is in a fixed longitudinal orientation relative to the distal cage.

### Claim 12 (depends on 1)

The expandable interbody of claim 1, wherein the adjustment screw threadingly engages with both the proximal cage and the distal cage.

### Claim 13 (depends on 1)

The expandable interbody of claim 1, wherein the adjustment screw comprises a twin screw having a proximal screw and a distal screw, the proximal screw having a threaded bore open at its distal end and configured to threadingly receive the distal screw.

### Claim 14 (depends on 1)

The expandable interbody of claim 1, wherein both the superior and inferior shells are curved toward each other at their respective distal ends so as to form a bullet-like nose shape that at least partially encloses the distal end of the interbody when in a collapsed configuration.

### Claim 15 (depends on 1)

The expandable interbody of claim 1, wherein—when in an expanded configuration—the superior shell, inferior shell, proximal cage, and distal cage each comprise openings therethrough extending from the superior surface of the superior shell to the inferior surface of the inferior shell so as to define a channel for bone growth.

### Claim 16 (depends on 1)

The expandable interbody of claim 1, wherein at least one of the superior shell, inferior shell, proximal cage, distal cage, and adjustment screw comprises a porous material.

### Claim 17 (depends on 16)

The expandable interbody of claim 16, wherein the porous material comprises layers of porous sheets that have been diffusion-bonded to form a uniform material.

### Claim 18 (depends on 1)

The expandable interbody of claim 1, wherein the superior surface defines a first plane and the inferior surface defines a second plane that is substantially parallel to the first plane when the interbody is in a collapsed configuration.

### Claim 19 (depends on 18)

The expandable interbody of claim 18, wherein the first plane is substantially parallel to the second plane when the interbody is in an expanded configuration.

### Claim 20 (depends on 18)

The expandable interbody of claim 18, wherein the first plane is substantially not parallel to the second plane when the interbody is in an expanded configuration.