AU2016338401B2

AU2016338401B2 - Interbody spacer

Info

Publication number: AU2016338401B2
Application number: AU2016338401A
Authority: AU
Inventors: Clint Boyd; Megan Carnes; Jordan Floyd; Jennifer Moore; Stephen Truesdell; Todd Wallenstein
Original assignee: K2M Inc
Current assignee: K2M Inc
Priority date: 2015-10-13
Filing date: 2016-10-13
Publication date: 2021-09-30
Anticipated expiration: 2036-10-13
Also published as: EP3361999A1; AU2016338401A1; EP3361999A4; WO2017066443A1

Abstract

An interbody spacer is provided including a body portion defining a longitudinal axis. The body portion includes a distal end portion, a proximal end portion, opposed side surfaces that extend between the distal and proximal end portions, and top and bottom surfaces configured and adapted to engage vertebral bodies. The interbody spacer includes first orifices defined through the top surface. The first orifices include orifices having first and second cross-sectional configurations and the first orifices are arranged in rows extending along the longitudinal axis.

Description

INTERBODYSPACER CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to, and the benefit of U.S. Provisional Patent

Application Serial No. 62/240,662, filed on October 13, 2015, the entire content of which is

hereby incorporated by reference herein.

BACKGROUND

Technical Field

[0002] The present disclosure relates to an apparatus for treating spinal conditions, and

more particularly, to an interbody spacer and a method of use therefor.

Background ofRelated Art

[0003] The human spinal column is a highly complex structure. It includes twenty-four

discrete bones, known as vertebrae, coupled sequentially to one another to house and protect critical

elements of the nervous system. The vertebrae interlock with one another to form a spinal column.

Each vertebra has a cylindrical bony body (vertebral body), two pedicles extending from the

vertebral body, a lamina extending from the pedicles, two wing-like projections extending from the

pedicles, a spinous process extending from the lamina, a pars interarticularis, two superior facets

extending from the pedicles, and two inferior facets extending from the lamina.

[0004] The vertebrae are separated and cushioned by thin pads of tough, resilient fiber

known as inter-vertebral discs. Inter-vertebral discs provide flexibility to the spine and act as shock

absorbers during activity. A small opening (foramen) located between each vertebra allows

passage of nerves. When the vertebrae are properly aligned, the nerves pass through without a problem. However, when the vertebrae are misaligned or a constriction is formed in the spinal canal, the nerves get compressed and may cause back pain, leg pain, or other neurological disorders.

[0005] For many reasons, such as aging and trauma, the intervertebral discs can begin to

deteriorate and weaken, potentially resulting in chronic pain, degenerative disc disease, or even

tearing of the disc. Ultimately, the disc may deteriorate or weaken to the point of tearing and

herniation, in which the inner portions of the disc protrude through the tear. A herniated disc may

press against, or pinch, the spinal nerves, thereby causing radiating pain, numbness, tingling, and/or

diminished strength or range of motion.

[0006] Many treatments are available to remedy these conditions, including surgical

procedures in which one or more damaged intervertebral discs are removed and replaced with a

prosthetic. After a partial or complete discectomy, the normally occupied space between adjacent

vertebral bodies is subject to collapse and/or misalignment due to the absence of all or part of the

intervertebral disc. In such situations, the physician may insert one or more prosthetic spacers

between the affected vertebrae to maintain normal disc spacing and/or the normal amount of lordosis

in the affected region.

[00071 Typically, a prosthetic implant is inserted between the adjacent vertebrae and may

include pathways that permit bone growth between the adjacent vertebrae until they are fused

together. However, there exists a possibility that conventional prosthetic implants may be dislodged

and moved from their desired implantation location due to movement by the patient before sufficient

bone growth has occurred.

[0008] Bone growth is a key factor in ensuring adequate retention of the implant to the

vertebra. Specifically, bone ingrowth within and around the prosthetic implant promotes fusion

between the adjacent vertebra, thereby strengthening the joint therebetween. However, conventional implants do not allow optimal space for bone ingrowth. In these instances, as the prosthetic implants do not mimic bone density of the adjacent vertebra, the body may reject the implant, and non-union

(i.e., no fusion) may occur.

[0009] Conventional prosthetic implants are typically constructed in a manner that inhibits

bone ingrowth, particularly those that include no spaces or avenues for such bone growth to occur

within and around the prosthetic implant. The lack of fusion may allow the implant to become

dislodged or moved from its desired location. Additionally, in the instances where the prosthetic

implant includes a lumen for the packing of ingrowth material, the material is often able to dislodge

from the lumen, and in some instances, from the implant, thereby reducing the chances that adequate

bone ingrowth occurs.

[0010] Therefore, a need exists for a prosthetic implant that can mimic the density of bone or

adequately retain ingrowth material therein to allow for optimal bone ingrowth and provide a solid

fusion of the vertebral segments.

[0010A] The reference to prior art in the background is not and should not be taken as an

acknowledgement or suggestion that the referenced prior art forms part of the common general

knowledge in Australia or in any other country.

SUMMARY

[0011] In accordance with an embodiment of the present disclosure, there is provided an

interbody spacer including a body portion defining a longitudinal axis. The body portion includes

a distal end portion, a proximal end portion, opposed side surfaces that extend between the distal

and proximal end portions, and top and bottom surfaces configured and adapted to engage

vertebral bodies. The interbody spacer includes first orifices defined through the top surface.

The first orifices include orifices having first and second cross-sectional configurations and are

arranged in rows extending along the longitudinal axis.

[0012] In embodiments, the second cross-sectional configuration may be larger than the

first cross-sectional configuration. The first orifices may be arranged in each row of the

longitudinal rows in an alternating pattern of orifices having first and second cross-sectional

configurations.

[0013] In embodiments, the first orifices may include orifices with a third cross-sectional

configuration, wherein the third cross-sectional configuration is larger than the second cross

sectional configuration. The first orifices may be arranged in each row of the longitudinal rows

in a pattern, such that the cross-sectional configuration of each orifice of the first orifices

increases from the first cross-sectional configuration to the third cross-sectional configuration.

Alternatively, the first orifices may be arranged in a random pattern.

[0014] In embodiments, each orifice of the first orifices may include a cross-sectional

configuration selected from the group consisting of arcuate, more than four sides, quadrilateral,

triangle, and sinusoidal.

[0015] In embodiments, each orifice of the first orifices may include a cross-sectional

configuration selected from the group consisting of oval, kidney, elliptical, circular, teardrop,

semicircle, and ovoid.

[0016] In embodiments, each orifice of the first orifices may include a cross-sectional

configuration selected form the group consisting of squircle, square, rhombus, trapezoid, and

rectangle.

[00171 In embodiments, each orifice of the first orifices may include a cross-sectional

configuration selected from the group consisting of hexagon, octagon, heptagon, and pentagon.

[00181 In embodiments, each orifice of the first orifices may include a cross-sectional

configuration selected from the group consisting of isosceles, equilateral, scalene, arrowhead

with arcuate base, and right.

[0019] In embodiments, each orifice of the first orifices may include a cross-sectional

configuration selected from the group consisting of greek cross and clover.

[0020] In embodiments, second orifices may be defined through the bottom surface. One

of the first orifices may include a cross-sectional configuration different than that of one of the

second orifices. One of the first orifices may be offset from one of the second orifices.

[0021] In embodiments, a respective orifice of the first and second orifices may be in

open communication, thereby defining a respective channel through the body portion. Each

channel includes a cross-sectional configuration that varies in a direction from the top surface to

the bottom surface.

[0022] In embodiments, each channel may include a sinusoidal cross-sectional

configuration. Alternatively, each channel may include a cross-sectional configuration including

spherical, cylindrical, frusto conical, ellipsoidal, hyperboloid, or any combination thereof.

Alternatively, each channel may include a cross-sectional configuration including helical

grooves disposed on an inner wall surface thereof.

[00231 In embodiments, a respective orifice of the first orifices may be in open

communication with an orifice defined through one of the opposed side surfaces, thereby

defining a respective channel through the body portion.

[0023A] An embodiment of the disclosure provides an interbody spacer comprising a body

portion defining a longitudinal axis, the body portion including a distal end portion, a proximal

end portion, opposed side surfaces that extend between the distal and proximal end portions, and top and bottom surfaces configured and adapted to engage vertebral bodies; first orifices defined through the top surface; and second orifices defined through the bottom surface, wherein a respective orifice of the first and second orifices is in open communication thereby defining a channel therebetween, wherein the channel defines a plurality of cross-sections, a center cross section of the plurality of cross-sections defining a cross-sectional area that is greater than cross sections disposed adjacent the top surface and the bottom surface.

[0023B] An embodiment of the disclosure provides an interbody spacer comprising a body

end portion, opposed side surfaces that extend between the distal and proximal end portions, and

top and bottom surfaces configured and adapted to engage vertebral bodies; first orifices defined

through the top surface; and second orifices defined through the bottom surface, wherein a

respective orifice of the first and second orifices is in open communication thereby defining a

first channel therebetween, the first channel being connected to a third orifice extending through

the top surface; and a second channel extending between the third orifice and a fourth orifice, the

fourth orifice extending through the bottom surface, wherein the first channel is in fluid

communication with the second channel.

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Various embodiments of the present disclosure are described hereinbelow with

reference to the drawings, wherein:

[0025] FIG. 1 is a rear, perspective view of an interbody spacer provided in accordance

with the present disclosure;

[0026] FIG. 2, is a side view of the interbody spacer of FIG. 1;

[00271 FIG. 3 is a top view of the interbody spacer of FIG. 1;

[00281 FIG. 4 is a top view of another embodiment of an interbody spacer similar to the

interbody spacer of FIG. 1;

[0029] FIG. 5 is a top view of yet another embodiment of an interbody spacer similar to

the interbody spacer of FIG. 1;

[0030] FIG. 6 is a top view of still another embodiment of an interbody spacer similar to

the interbody spacer of FIG. 1;

[00311 FIG. 7 is a top view of another embodiment of an interbody spacer similar to the

interbody spacer of FIG. 1, without a cavity extending therethrough;

[0032] FIG. 8 is a side, cross-sectional, view of the interbody spacer of FIG. 7, taken

along section-line 8-8 of FIG. 7;

[00331 FIG. 8A is a side, cross-sectional, view of an alternate embodiment of the

interbody spacer of FIG. 7, taken along section-line 8-8 of FIG. 7;

[0034] FIG. 8B is a side, cross-sectional, view of an alternate embodiment of the

interbody spacer of FIG. 8, taken along section-line 8-8 of FIG. 7;

[00351 FIG. 9 is an illustration of a family of cross-sectional shapes for an orifice defined

through an interbody spacer in accordance with the present disclosure;

[00361 FIG. 10 is an illustration of another family of cross-sectional shapes for an orifice

defined through an interbody spacer in accordance with the present disclosure;

[00371 FIG. 11 is an illustration of yet another family of cross-sectional shapes for an

orifice defined through an interbody spacer in accordance with the present disclosure;

[00381 FIG. 12 is an illustration of still another family of cross-sectional shapes for an

[00391 FIG. 13 is an illustration of another family of cross-sectional shapes for an orifice

defined through an interbody spacer in accordance with the present disclosure;

[0040] FIG. 14 is an illustration still another family of cross-sectional shapes for an

[0041] FIG. 15 is an illustration of yet another family of cross-sectional shapes for an

[0042] FIG. 16 is a side, cross-sectional view, of a family shapes for a channel defined

through an interbody spacer in accordance with the present disclosure;

[00431 FIG. 17 is a side, cross-sectional view, of another family of shapes for a channel

defined through an interbody spacer in accordance with the present disclosure;

[0044] FIG. 18 is a side, cross-sectional view, of yet another family of shapes for a

channel defined through an interbody spacer in accordance with the present disclosure;

[0045] FIG. 19 is a side, cross-sectional view, of still another family of shapes for a

[00461 FIG. 20 is a side, cross-sectional view, of another family of shapes for a channel

defined through an interbody spacer in accordance with the present disclosure;

[00471 FIG. 21 is a side, cross-sectional view, of still another family of shapes for a

[00481 FIG. 22 is a side, cross-sectional view, of yet another family of shapes for a

channel defined through an interbody spacer in accordance with the present disclosure; and

[0049] FIG. 23 is a side, cross-sectional view, of still another family of shapes for a

channel defined through an interbody spacer in accordance with the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

[0050] Embodiments of the present disclosure are now described in detail with reference

to the drawings in which like reference numerals designate identical or corresponding elements

in each of the several views. As commonly known, the term "clinician" refers to a doctor, a

nurse, or any other care provider and may include support personnel. Additionally, the term

"proximal" refers to the portion of the device or component thereof that is closer to the clinician

and the term "distal" refers to the portion of the device or component thereof that is farther from

the clinician. In addition, the term "cephalad" is known to indicate a direction toward a patient's

head, whereas the term "caudal" indicates a direction toward the patient's feet. Further still, for

the purposes of this application, the term "lateral" indicates a direction toward a side of the body

of the patient, i.e., away from the middle of the body of the patient. The term "posterior"

indicates a direction toward the patient's back, and the term "anterior" indicates a direction

toward the patient's front. Additionally, in the drawings and in the description that follows,

terms such as front, rear, upper, lower, top, bottom, and similar directional terms are used simply

for convenience of description and are not intended to limit the disclosure. In the following

description, well-known functions or constructions are not described in detail to avoid obscuring

the present disclosure in unnecessary detail.

[0051] Referring now to the drawings, FIGS. 1-3 illustrate an interbody spacer provided

in accordance with the present disclosure and generally identified by reference numeral 10.

Interbody spacer 10 includes a body portion 12 having a substantially contoured first end surface

14 (FIG. 2) at a distal or leading end 16 and a second end surface 18 opposite thereto at a

proximal or trailing end 20, having a substantially planar configuration. Axis A-A (FIG. 3) is

defined through a midpoint of first and second end surfaces 14, 18, respectively. Body portion

12 extends between first and second end surfaces 14, 18 to define respective top and bottom

surfaces 22 and 24 (FIG. 2), respectively, as well as opposed side surfaces 26, 28 (FIG. 3). As

best illustrated in FIG. 2, top and bottom surfaces 22, 24 include a generally convex or arcuate

profile, each extending in a cephalad and caudal direction (or vice-versa), respectively.

Although shown and described as the top surface 22 being oriented in a cephalad direction and

the bottom surface 24 being oriented in a caudal direction, the interbody spacer 10 may be

positioned such that the top surface 22 is in a caudal orientation and the bottom surface 24 is in a

cephalad orientation. As can be appreciated, top and bottom surfaces 22 and 24 may include a

concave profile, a planar profile, or any combination thereof. In embodiments, top surface 22

may include a different profile than that of bottom surface 24. Additionally, it is contemplated

that top and bottom surfaces 22, 24 may approximate in a direction along axis A-A (or vice

versa), or may approximate in a direction from side surface 26 towards side surface 28 (or vice

versa), or any combination thereof.

[0052] As best illustrated in FIG. 3, opposed side surfaces 26, 28 are substantially planar,

although other configurations are also contemplated such as convex, concave, or the like.

Opposed side surfaces 26, 28 approximate towards each other at distal end 16 along longitudinal

axis A-A in order to facilitate insertion within the intervertebral space and enhance the

atraumatic character of body portion 12. In this manner, the intersection of top and bottom

surfaces 22, 24 with each of first and second end surfaces 14, 18 and opposed side surfaces 26,

28 may include a fillet or rounded configuration 30 to inhibit sharp edges from causing trauma to

the surrounding tissue and/or vertebral bodies.

[0053] Referring again to FIG. 1, second end surface 18 includes an aperture 32 defined

therethrough and extending along longitudinal axis A-A. Aperture 32 is configured for selective engagement with a suitable insertion tool (not shown), such as that described in U.S. Patent

Application No. 2012/0158062, filed October 11, 2011, the entire contents of which are hereby

incorporated by reference herein. In embodiments, aperture 32 may be threaded or otherwise

include various features capable of selectively retaining a suitable insertion tool (not shown)

therein, such as a keyhole configuration, quarter-turn configuration, or the like.

[0054] Each of opposed side surfaces 26, 28 includes a corresponding depression or

recess 26a, 28a defined therein adjacent second end surface 18. Recesses 26a, 28a extend along

longitudinal axis A-A and are symmetrically disposed on each of opposed side surfaces 26, 28 to

define a substantially I-shaped configuration to second end surface 18 at proximal end 20. In

cooperation with aperture 32, the recesses 26a, 28a are further configured to enable engagement

with stabilizing jaws of a suitable insertion instrument (not shown) to facilitate the insertion of

interbody spacer 10. As can be appreciated, interbody spacer 10 may not include recesses 26a,

28a, and rather, include planar side surfaces 26, 28 that extend between first and second end

surfaces 14, 18.

[0055] Body portion 12 includes a through-bore or cavity 34 defined through top and

bottom surfaces 22, 24, respectively. Although shown as having a generally oval configuration,

it is contemplated that through-bore 34 may include any suitable shape such as square,

rectangular, circular, or the like, or may include a configuration similar to that of the outer

perimeter of body portion 12. It is contemplated that through-bore 34 may receive allograft

material, autograft material, calcium phosphate/bone marrow aspirate (BMA), autogenous

material, synthetic materials comprised of a biocompatible osteoconductive, osteoinductive, or

osteogeneic material such as VITOSS© Synthetic Cancellous Bone Void Filler material, or any

other suitable biological material known in the art. Through-bore 34 includes a cross-sectional area or surface area that is greater than any orifice of the plurality of orifices or enlarged orifices detailed hereinbelow. In embodiments, through-bore 34 includes a surface area that is equal to or greater than 25% of the surface area of top surface 22 or bottom surface 24.

[0056] Top and bottom surfaces 22, 24 of body portion 12 are configured to engage

respective endplates of adjacent vertebral bodies. In this manner, each of top and bottom

surfaces 22, 24 includes at least first and second surface regions 22a, 22b and 24a, 24b,

respectively, which have distinct surface characteristics. As best illustrated in FIG. 2, first

surface regions 22a, 24a are disposed distal to second surface regions 22b, 24b and include a

surface characteristic that is different than that of second surfaces 22b, 24b. In embodiments,

first surface regions 22a, 24a may include a same or similar surface characteristic to that of

second surface regions 22b, 24b, or each of first and second surface regions 22a, 24a and 22b,

24b may include the same or different surface characteristics, or any combination thereof.

[00571 First surface regions 22a, 24a each have a plurality of protrusions (i.e., teeth) or

ridges 36 disposed thereof to aid in securing interbody spacer 10 to each respective adjacent

vertebral body and stability against fore and aft, oblique or side to side movement of interbody

spacer 10 within the intervertebral space. Specifically, protrusions 36 frictionally engage

endplates of adjacent vertebral bodies and inhibit movement of the interbody spacer 10 with

respect to the adjacent vertebral bodies. In embodiments, a plurality of longitudinal grooves 38

(FIGS. 1 and 3) may be defined within protrusions 36, each of which extends along longitudinal

axis A-A. Each of second surface regions 22b, 24b includes substantially pyramidal protrusions

40, where each pyramidal protrusion 40 includes a plurality of protrusions or ridges disposed

thereon to similarly aid in securing interbody spacer 10 to each respective adjacent vertebral

body. In particular, each pyramidal protrusion 40 includes opposed first and second faces that face, respectively, distally and proximally. Further, each pyramidal protrusion 40 has third and fourth faces that face, respectively, medially and laterally. For a detailed description of an interbody spacer having exemplary surface characteristics, reference can be made to U.S. Patent

No. 8,801,791 to Soo et al., filed September 27, 2007, the entire contents of which are hereby

incorporated by reference herein.

[0058] Interbody spacer 10 is constructed of a biocompatible material, such as

commercially pure titanium or titanium alloy and includes a porosity capable of promoting bone

ingrowth and fusion with interbody spacer 10. In this manner, top and bottom surfaces 22, 24

and opposed side surfaces 26, 28 have a surface roughness that can promote bone growth and

fusion with interbody spacer 10. The surface roughness may be in a range of about 0.10-50 [m,

and preferably in a range of about 3-4 m. As can be appreciated, top and bottom surfaces 22,

24 and opposed side surfaces 26, 28 may include the same or different surface roughness's (i.e.,

the surface roughness of top surface 22 may be different than the surface roughness of bottom

surface 24), or top and bottom surfaces 22, 24 and opposed side surfaces 26, 28 may not include

a surface roughness; rather, top and bottom surfaces 22, 24 and opposed side surfaces 26, 28 may

be smooth. In embodiments top and bottom surfaces 22, 24 and opposed side surfaces 26, 28

may include any combination of surface roughness or smooth surface. Additionally, body

portion 12 includes a plurality of orifices 44 and 46 defined through top and bottom surfaces 22,

24 and opposed side surfaces 26, 28, respectively, configured to promote bone ingrowth.

Although illustrated as having a generally circular cross-section, orifices 44 may include any

suitable cross-section, as will be described in further detail hereinbelow. Orifices 46 are

illustrated as having a generally diamond shaped cross-section, however, it is contemplated that

orifices 46 may include any suitable cross-section, as will be described in further detail hereinbelow. The cross-sectional shapes of orifices 44, 46 mimic bone growth along Haversian canals and lamellar structures of bone. The plurality of orifices 44, 46 reduces the density and stiffness of interbody spacer 10 to enable the application of bone putty or the like (e.g., bone morphogenetic proteins, etc.) to interbody spacer 10 to promote bone ingrowth within interbody spacer 10 and fusion to adjacent vertebral bodies. Bone ingrowth and fusion strengthens interbody spacer 10. In this manner, the likelihood that micromotion would occur would be reduced.

[0059] As best illustrated in FIG. 3, the plurality of orifices 44 are arranged in evenly

spaced longitudinal rows along longitudinal axis A-A. The plurality of orifices 44 includes

orifices with a first diameter 44a, orifices with a second diameter 44b, and orifices with a third

diameter 44c. In one non-limiting embodiment, the first diameter 44a is 30 m, the second

diameter 44b is 150 [m, and the third diameter 44c is 500 [m, although other suitable diameters

are also contemplated. As can be appreciated, each of the orifices 44 may include a cross-section

corresponding to any cross-sectional shape detailed herein. As such, the cross-sectional area of

each of orifice 44a, 44b, and 44c may be 0.000707 m 2 , 0.0177 m 2 , and 0.196 m 2

, respectively. In this manner, the plurality of orifices 44 is defined through top and bottoms

surfaces 22, 24 and arranged in groups of three orifices, 44a, 44b, 44c, that define a respective

pattern along axis A-A of body portion 12.

[0060] Referring to FIG. 4, another embodiment of an interbody spacer provided in

accordance with the preset disclosure is illustrated and generally identified by reference numeral

110. Interbody spacer 110 is substantially similar to interbody spacer 10, and therefore only the

differences therebetween will be described in detail in the interest of brevity. The orifices of the

plurality of orifices 144 include orifices with a first diameter 144a and orifices with a second, larger, diameter 144b. In one non-limiting embodiment, the diameter of the first diameter 144a is 150 m and the diameter of the second diameter 144b is 500 m, although other diameters are also contemplated. As can be appreciated, each of the orifices 144 may include a cross-section corresponding to any cross-sectional shape detailed herein. As such, the cross-sectional area of each of orifice 144a and 144b may be 0.0177 m 2 and 0.196 m 2 , respectively. In this manner, a pair of rows of orifices 144 having the second, larger diameter 144b is defined through the distal end 116 of top surface 122 and the bottom surfaces (not shown) and extending in a direction transverse to longitudinal axis A-A. A pair of rows of orifices 144 having the first diameter 144a is disposed proximal to the pair of rows of orifices 144 having the second, larger diameter 144b and extends in a direction transverse to longitudinal axis A-A. This pattern is repeated in a proximal (or distal) direction along axis A-A.

[0061] With reference to FIG. 5, yet another embodiment of an interbody spacer

provided in accordance with the present disclosure is illustrated and generally identified by

reference numeral 210. Interbody spacer 210 is substantially similar to interbody spacer 10, and

therefore only the differences therebetween will be described in detail in the interest of brevity.

The plurality of orifices 244 includes orifices having a first diameter 244a and orifices having a

second, larger, diameter 244b. In one non-limiting embodiment, the first diameter 244a is 150

tm and the second diameter 244b is 500 [m, although other diameters are also contemplated.

As can be appreciated, each of the orifices 244 may include a cross-section corresponding to any

cross-sectional shape detailed herein. As such, the cross-sectional area of each of orifice 244a

and 244b may be 0.0177 m 2 and 0.196 m 2 , respectively. In this manner, the plurality of

orifices 244 is defined through top and bottom surfaces 222, 224 such that the diameter of the

plurality of orifices 244 alternates between orifices having the first diameter 244a and orifices having the second, larger, diameter 244b in a direction along longitudinal axis A-A. This pattern is offset in a direction transverse to longitudinal axis A-A such that an orifice of the plurality of orifices 244 having a first diameter 244a is only adjacent an orifice of the plurality of orifices

244 having a second, larger, diameter 244b.

[0062] With reference to FIG. 6, still another embodiment of an interbody spacer

reference numeral 310. Interbody spacer 310 is substantially similar to interbody spacer 10, and

The plurality of orifices 344 includes orifices of various diameters. In one non-limiting

embodiment, the diameter of each orifice of the plurality of orifices 344 may vary between 50

m and 1000 m. As can be appreciated, each of the orifices 344 may include a cross-section

each of orifice 344 may be 0.0707 m2 and 0.385 m 2 . The plurality of orifices 344 is defined

through top surface 322 and the bottom surfaces (not shown) in a random manner such that there

are no defined rows, and the diameters of each orifice of the plurality of orifices 344 vary.

[0063] Referring now to FIGS. 7 and 8, an alternate embodiment of an interbody spacer

reference numeral 410. Interbody spacer 410 is substantially similar to interbody spacer 10, and

therefore, only the differences therebetween will be described in detail in the interest of brevity.

Interbody spacer 410 does not include a through-bore defined through top surface 422 and the

bottom surfaces (not shown). Rather, as best illustrated in FIG. 8, interbody spacer 410 includes

a void 448 defined within an interior portion of body 412. In this manner, void 448 does not

breach leading or trailing surface 414, 418, top or bottom surface 422, 424, or the opposed side surfaces 426, 428 (FIG. 7). In one non-limiting embodiment, aperture 432 extends through a proximal end of void 448 such that aperture 432 is in open communication therewith. Although illustrated as having a generally circular cross-section, it is contemplated that void 448 may include any suitable shape and/or volume, such as spheroid, ovoid, cuboid, rectanguloid, ellipsoid, or the like. In certain embodiments, void 448 may include an amorphous shape.

Additionally, as best illustrated in FIG. 8A, it is contemplated that void 448 may be isolated from

the plurality of orifices defined through top surface 422 and the plurality of orifices 446 defined

through the opposed side surfaces 426, 428 (FIG. 7), or only one or the other. It is further

contemplated that void 448 may include one or more protrusions (not shown) extending towards

an interior portion of void 448. As can be appreciated, the one or more protrusions may include

any suitable shape, such as frusto conical, spheroid, ovoid, cuboid, rectanguloid, conical,

ellipsoid, or the like. By varying the shape and or volume of void 448, the density and stiffness

of interbody spacer 410 may be likewise varied, thereby allowing a clinician to select an implant

more closely tailored to the density of adjacent vertebral bodies. In embodiments, interbody

spacer 448 may include a plurality of smaller voids 448 defined in an interior portion of body

412.

[0064] Alternatively, as best illustrated in FIG. 8B, interbody spacer 410 may include no

through-bore or void. In this manner, aperture 432 is blind (i.e., terminates in a distal face in an

interior portion of interbody spacer 410). Additionally, the plurality of orifices 446 defined

through the opposed side surfaces includes a diamond shaped cross-section 446a on distal and

proximal ends 416, 420 and a random array of orifices having a circular cross-section 446b and

varying diameters defined through the opposed side surfaces (not shown) at a medial portion of

body 412. As can be appreciated, the plurality of orifices 446 having a diamond-shaped cross section 446a may be defined through the medial portion of the opposed side surfaces and the random array of circular orifices 446b may be defined through distal and proximal ends 416, 420 of the opposed side surfaces, or any combination thereof.

[0065] Referring now to FIGS. 9-15, the plurality of orifices 44, 46 may include various

cross-sectional shapes of differing families. As illustrated in FIG. 9, orifices 44, 46 may include

a cross-sectional shape having varying curvature, designated as a first family 50. Cross-sectional

shapes included in first family 50 include oval 50a, kidney 50b, elliptical 50c, circular 50d,

teardrop 50e, semicircle 50f, and ovoid 50g. As can be appreciated, orifices 44, 46 from first

family 50 may include any cross-sectional shape having an arcuate, curvate, or otherwise

amorphous shape not otherwise illustrated in FIG. 9.

[0066] A second family 52 of cross-sectional shapes having more than four sides is

illustrated in FIG. 10. In this manner, the plurality of orifices 44, 46 may include a cross

sectional shape of a hexagon 52a, an octagon 52b, a heptagon 52c, and a pentagon 52d. As can

be appreciated, any polygon having more than four sides may be included in second family 52,

such as nonagon, decagon, dodecagon, etc.

[00671 With reference to FIG. 11, a third family 54 of cross-sectional shapes from which

the plurality of orifices 44, 46 may be defined is illustrated. Third family 54 includes

quadrilaterals, such as a square with rounded edges 54a (such as a squircle), square 54b, rhombus

54c, trapezoid 54d, and rectangle 54e. As can be appreciated, third family 54 may include any

quadrilateral, such as parallelogram, kite, isosceles trapezoid, trapezium, etc.

[0068] A fourth family 56 of cross-sectional shapes from which the plurality of orifices

44, 46 may be defined is illustrated in FIG. 12. Fourth family 56 includes triangles, such as isosceles 56a, equilateral 56b, scalene 56c, arrowhead with arcuate base 56d, and right 56e. As can be appreciated, fourth family 56 may include any type of triangle known in the art.

[0069] FIG. 13 illustrates a fifth family 58 of cross-sectional shapes from which the

plurality of orifices 44, 46 may be defined. Fifth family 58 includes a greek cross 58a and clover

58b, although other similar cross-sectional shapes are contemplated, like, cross, star, or the like.

[00701 As illustrated in FIG. 14, a sixth family 60 of cross-sectional shapes from which

the plurality of orifices 44, 46 may be defined includes sinusoidal shapes having various lengths,

widths, and number of sides. A first sinusoidal shape 60a includes a width that is larger than that

of a second sinusoidal shape 60b. A third sinusoidal shape 60c includes pointed opposed ends.

As can be appreciated, any suitable sinusoidal shape may be included in sixth family 60.

[00711 FIG. 15 illustrates a seventh family 62 of cross-sectional shapes from which the

plurality of orifices 44, 46 may be defined. The cross-sectional shapes included in the seventh

family 62 include ornate designs having various circular designs as illustrated in first design 62a

or rectangular designs as illustrated in second design 62b. First design 62a includes upper and

lower apertures 62aa and 62ab defining a generally oval shape. First design 62a includes a

plurality of additional bores 62ac defined in an interior portion thereof. In this manner, a

plurality of circular features resembling wheels and spokes and/or pinwheels are defined. The

plurality of bores 62ac define a corresponding plurality of bridges or spokes 62ad that separate

each of each of the upper and lower apertures 62aa, 62ab, and plurality of bores 62ac.

[0072] Similarly, second design 62b includes upper and lower apertures 62ba and 62bb

defining a generally rectangular shape. A plurality of elongate, arcuate, bores 62bc are defined

in an interior portion of second design 62b, the plurality of elongate, arcuate, bores 62bc defining

cooperating to define a generally triangular shape. The plurality of elongate, arcuate, bores 62bc define a corresponding plurality of bridges 62bd that separate each of the upper and lower apertures 62ba, 62bb and plurality of bores 62bc.

[0073] As can be appreciated, any of the above described families may be interchanged

or randomly selected as the cross-sectional shape of orifices 44, 46 defined through upper and

lower surfaces 22, 24 or opposed side surfaces 26, 28, respectively, of body portion 12. In

embodiments, the plurality of orifices 44 defined through top surface 22 may utilize a different

cross-sectional shape than that of the plurality of orifices 44 defined through bottom surface 24.

Similarly, the plurality of orifices 46 defined through side surface 26 may include a different

cross-sectional shape than the plurality of orifices 46 defined through opposite side surface 28. It

is contemplated that any number of combinations of cross-sectional shapes may be employed.

[0074] Referring now to FIGS 16-23, the plurality of orifices 44, 46 defined through top

and bottom surfaces 22, 24 and opposed side surfaces 26, 28 define a respective channel through

body portion 12. FIGS. 16-23 illustrate a variety of families of channels that may be defined

through body portion 12. As best illustrated in FIG. 16, a first family of channels 64 having a

generally arcuate profile is illustrated. The first family of channels 64 includes a first channel

64a having a generally arcuate profile. First channel 64a includes a pair of bowed or bulging

sidewalls and includes a constant width. A second channel 64b includes a generally sinusoidal

profile. A third channel 64c includes a pair of channels 64ca, 64cb defining a generally X

shaped configuration. In this manner, channel 64ca of the pair of channels is bowed in a first

direction and channel 64cb of the pair of channels bows in an opposite direction, such that

channels 64ca, 64cb intersect (i.e., channels 64ca and 64cb are in open communication). A

fourth channel 64d includes a generally hourglass profile. A fifth channel 64e includes an elliptical profile. As can be appreciated, first family of channels 64 may include any suitable profile having arcuate sidewalls.

[00751 FIG. 17 illustrates a second family of channels 66 having generally planar

sidewalls. First channel 66a includes planar sidewalls extending in a diagonal direction such that

the openings of an orifice of the plurality of orifices 44, 46 on the top and bottom surfaces 22,

24, respectively, are offset in relation to one another. A second channel 66b includes a generally

arrowhead or rotated chevron type profile (i.e., upper and lower portions extending diagonally

toward one another in a medial portion of body portion 12 to define a point). A third channel

66c includes a generally hourglass profile having planar sidewalls. A fourth channel 66d

includes a generally inverted hourglass profile (i.e., the width of fourth channel 66d increases at

a middle portion thereof).

[0076] A third family of channels 68 is illustrated in FIG. 18. Each channel of the third

family of channels 68 is mirrored about axis B-B defined at a medial portion of body 12. A first

channel 68a is defined through top surface 22 and includes a first cylinder 68aa having a first

diameter extending towards bottom surface 24. First cylinder 68aa transitions to a second

cylinder 68ab and includes a second, larger, diameter than the diameter of first cylinder 68aa. A

second channel 68b is essentially an inverse of first channel 68a. In particular, a first cylinder

68ba having a first diameter intersects top surface 22 and extends towards bottom surface 24.

First cylinder 68ba transitions to a second cylinder 68bb and includes a second, smaller, diameter

than the diameter of first cylinder 68ba.

[00771 Referring now to FIG. 19, a fourth family of channels 70 is illustrated. A first

channel 70a is defined through top surface 22 of body portion 12 and includes a generally

arcuate shape such that first channel 70a curves towards, and extends through, one of opposed side surfaces 26, 28. A second channel 70b is defined through bottom surface 24 of body portion

12 and includes a generally arcuate shape such that second channel 70b curves towards, and

extends through, an opposite one of opposed side surfaces 26, 28 than that of first channel 70a.

[0078] FIG. 20 illustrates a fifth family of channels 72 including similar profile to that of

the fourth family of channels 70. In this manner, a first channel 72a includes a tighter radius of

curvature than that of a second, opposed channel 72b. As can be appreciated, second channel

72b may have a tighter radius than that of first channel 72a.

[00791 A sixth family of channels is illustrated in FIG. 21 and is generally identified by

reference numeral 74. Each channel of the third family of channels 74 is mirrored about axis B

B defined at a medial portion of body 12. A first channel 74a includes a frusto conical profile

74aa defined through top surface 22 of body portion 12 extending towards bottom surface 24.

Frusto conical profile 74aa includes a generally inverted orientation (i.e., the diameter decreases

in a direction from top surface 22 towards bottom surface 24). Frusto conical profile 74aa

transitions to a cylindrical profile 74ab at a medial portion of body portion 12 having a larger

diameter than that of the portion of frusto conical profile 74aa that intersect cylindrical profile

74ab.

[0080] A second channel 74b includes a substantially similar profile to that of first

channel 74a except that the frusto conical profile 74ba is inverted with respect to frusto conical

profiles 74aa of first channel 74a.

[0081] Third channel 74c includes first portion 74ca having a generally hourglass

configuration that intersects top surface 22 of body portion 12 and extends towards bottom

surface 24. First portion 74ca transitions to a second portion 74cb having a generally cylindrical

configuration at a medial portion of body portion 12.

[00821 A fourth channel 74d includes a first portion 74da having a generally spherical

configuration. First portion 74da is defined through top surface 22 of body portion 12 and

extends towards bottom surface 24. First portion 74da transitions to a second portion 74db

having a generally cylindrical configuration at a medial portion of body portion 12. Second

portion 74db includes a diameter less than the diameter of first portion 74da.

[0083] FIG. 22 illustrates a seventh family of channels generally identified by reference

numeral 76. Each channel of the third family of channels 76 is mirrored about axis B-B defined

at a medial portion of body 12. A first channel 76a includes a first and second spherical portion

76aa and 76ab respectively, disposed in a generally stacked configuration such that first spherical

portion extends through upper surface 22 of body 12. Each offirst and second spherical portions

76aa and 76ab include a generally similar diameter, although other configurations are also

contemplated.

[0084] A second channel 76b includes a first portion 76ba defined through top surface 22

of body portion 12 and extending towards bottom surface 24. First portion 76ba includes a

generally cylindrical configuration and transitions to a second portion 76bb having a generally

spherical configuration at a medial portion of body portion 12.

[0085] Third channel 76c includes a first portion 76ca having a generally inverted frusto

conical configuration (i.e., the diameter of first portion decreases in a direction from top surface

22 towards bottom surface 24). First portion 76ca is defined through top surface 22 of body

portion 12 and extends towards bottom surface 24. First portion 76ca transitions to a second

portion 76cb having a generally ellipsoid configuration at a medial portion of body portion 12,

although it is contemplated that second portion 76cb may include a generally spherical

configuration similar to that of second portion 76bb of second channel 76b.

[00861 Fourth channel 76d is similar to that of third channel 76c except that the first

portions 76da includes a frusto conical configuration that is inverted relative to first portion 76ca

of third channel 76c. Second portion 76db includes a generally spherical configuration.

[00871 A fifth channel 76e includes a first portion 76ea having a generally hourglass

configuration. First portion 76ea is defined through top surface 22 of body portion 12 and

extends towards bottom surface 24. First portion 76ea transitions to a second portion 76eb

having a generally spherical configuration at a medial portion of body portion 12.

[0088] FIG. 23 illustrates an eighth channel 78 defined through top and bottom surfaces

22, 24 of body portion 12. Eighth channel 78 includes a generally cylindrical profile including

helical grooves 78b defined on an inner sidewall 78a thereof.

[0089] Although each orifice and channel has been hereinabove described as being

defined through top and bottom surfaces 22, 24 of body 12, as can be appreciated, the orifices

and channels may be defined through opposed side surfaces 26, 28.

[0090] As can be appreciated, manufacturing interbody spacers 10, 110, 210, 310, and

410 using standard machining methods (e.g., lathe, mill, EDM, etc.) could be difficult. In view

of this, it is contemplated that in addition to manufacturing interbody spacers 10, 110, 210, 310,

and 410 using the aforementioned conventional means, interbody spacers 10, 110, 210, 310, and

410 may be manufactured by means of additive manufacturing methods (e.g., SDM, SLPP,

DMLS (i.e., EOS), SLS, SLM, SHS, EBM, VAT photopolymerisation, material jetting, binder

jetting, or the like). In one non-limiting embodiment, interbody spacers 10, 110, 210, 310, and

410 may be manufactured using Selective Laser Powder Processing (SLPP). SLPP utilizes

powdered metal and a laser which sinters or cures the metal in a selective fashion according to

the design intent in thin layers. In embodiments, the layers have a thickness of about 250 [m.

Interbody spacers 10, 110, 210, 310, and 410 are built layer by layer to allow for more design

options and features that would be difficult to be machined using conventional methods.

Specifically, a first layer of powder is applied to a specialized build plate, at which point the

laser cures portions of the powder according to the design intent. At this point, a second layer is

applied to the build plate and the laser is again used to cure selective portions of this second

layer. This process is repeated until interbody spacers 10, 110, 210, 310, and 410 are fully

formed. Once interbody spacers 10, 110, 210, 310, and 410 are fully formed, uncured powder is

removed using compressed air or other similar means. Next, post machining is performed on

interbody spacers 10, 110, 210, 310, and 410 to remove any burrs or similar imperfections

embedded within interbody spacers 10, 110, 210, 310, and 410 during the additive

manufacturing process. In embodiments, the burrs are removed by means of buffer wheels,

clippers, files, or the like. Once de-burred, interbody spacers 10, 110, 210, 310, and 410 are heat

treated, and thereafter, media blasted using aluminum oxide. Thereafter, interbody spacers 10,

110, 210, 310, and 410 are immersed in a hydrofluoric bath to strip the aluminum oxide

therefrom. Finally, interbody spacers 10, 110, 210, 310, and 410 are inspected by quality

control personnel (or using automated means), cleaned via ultrasonic cleaning, dried, and

packaged. It is contemplated that the design of interbody spacers 10, 110, 210, 310, and 410

may be customized for each specific patient using SLPP. For a detailed description of exemplary

manufacturing methods, reference may be made to U.S. Patent No. 8,590,157, issued on

November 26, 2013 to Kruth et al., the entire contents of which are hereby incorporated by

reference herein.

[0091] Interbody spacers 10, 110, 210, 310, and 410 may be constructed from

commercially pure titanium, titanium alloy, cobalt-chrome, ceramic, Polyetheretherketone

(PEEK), or any other suitable biocompatible material. In embodiments, interbody spacers 10,

110, 210, 310, and 410 may be manufactured using a three-dimensional printer utilizing a

biocompatible polymer.

[0092] With reference to FIGS. 1-8B, in use, an intervertebral space is first prepared,

e.g., damaged or diseased tissue is removed. As the construction of interbody spacer 10 is

similar to that of interbody spacers 110, 210, 310, and 410, only the method of use of interbody

spacer 10 will be described in detail for purposes of brevity. An appropriately sized interbody

spacer 10 is selected based on the patient's spinal characteristics and the desired amount of

lordosis. Next, the interior space of through-bore 34 of body portion 12 may be packed with

bone in-growth material, drugs, or other suitable materials or compounds. Examples of such

materials are allograft material, or synthetic materials comprised of a biocompatible,

Bone Void Filler material. Next, a suitable insertion instrument (not shown) is threaded into

aperture 32 of body portion 12 until interbody spacer 10 is securely affixed to the insertion

instrument. At this point, interbody spacer 10 is advanced within an incision within the patient,

and thereafter, the previously prepared inverterterbal space of the patient's spine. Once

interbody spacer 10 is placed within the intervertebral space such that interbody spacer 10 rests

on the distal apophyseal ring of the vertebral body, the tool (not shown) is released from aperture

32, and thereafter, the incision within the patient. By residing on the apophyseal ring, interbody

spacer 10 is less likely to experience subsidence into the end plates which will facilitate fusion

between the intervertebral plates.

[00931 This process may be repeated as many times as the procedure requires, whether it

be for the same interbody spacer 10 or for a plurality of interbody spacers 10 as required by the

procedure being performed.

[0094] It is envisioned that the manufacturing processes and orifice designs detailed

above may be utilized to form various other medical devices known in the art. In this manner, the

additive manufacturing process detailed above may be employed to form corpectomy devices,

fixed spinal implants, expandable spinal implants, bone screws, cervical implants, and the like.

Similarly, the orifice designs detailed above may be formed in any of the beforementioned

medical devices that would benefit from an increased ability to fuse with bone. Examples of

such devices may be found in the following commonly owned references: U.S. Patent No.

8,585,761 to Theofilos, U.S. Patent No. 8,673,011 to Theofilos et al., U.S. Application Serial No.

14/936,911 to Sutterlin et al., U.S. Patent No. 8,801,791 to Soo et al., U.S. Patent No. 8,439,977

to Kostuik et al., U.S. Patent Application Publication No. 2010/0100131 to Wallenstein, U.S.

Patent Application Publication No. 2012/0179261 to Soo, U.S. Patent No. 8,449,585 to

Wallenstein et al., U.S. Patent No. 8,814,919 to Barrus et al., U.S. Patent No. 5,733,286 to Errico

et al., and U.S. Patent Application Publication No. 2013/0046345 to Jones et al.

[0095] It will be understood that various modifications may be made to the embodiments of

the presently disclosed interbody spacer. Therefore, the above description should not be construed as

limiting, but merely as exemplifications of embodiments. Those skilled in the art will envision other

modifications within the scope and spirit of the present disclosure.

[0095A] In this specification, the terms "comprises", "comprising", "includes",

"including", and similar terms are intended to mean a non-exclusive inclusion, such that a product, system, or method, etc., that comprises or includes a list of elements need not have those elements solely, and may well have other elements not listed.

Claims

What is claimed is:

1. An interbody spacer comprising:

a body portion defining a longitudinal axis, the body portion including a distal end

portion, a proximal end portion, opposed side surfaces that extend between the distal and

proximal end portions, and top and bottom surfaces configured and adapted to engage

vertebral bodies;

first orifices defined through the top surface; and

second orifices defined through the bottom surface, wherein a respective orifice of the

first and second orifices is in open communication thereby defining a first channel

therebetween, the first channel being connected to a third orifice extending through the top

surface; and

a second channel extending between the third orifice and a fourth orifice, the fourth

orifice extending through the bottom surface, wherein the first channel is in fluid

communication with the second channel,

wherein at least one of the first and second channel defines a plurality of cylinders, a

center cylinder having a cross-sectional area greater than a cross-sectional area of adjacent

cylinders.

2. An interbody spacer comprising:

vertebral bodies;

first orifices defined through the top surface; and second orifices defined through the bottom surface, wherein a respective orifice of the first and second orifices is in open communication thereby defining afirst channel therebetween, the first channel being connected to a third orifice extending through the top surface; and a second channel extending between the third orifice and a fourth orifice, the fourth orifice extending through the bottom surface, wherein the first channel is in fluid communication with the second channel, wherein at least one of the first and second channel defines a plurality of spheres, a center sphere having a cross-sectional area different than a cross-sectional area of adjacent spheres.

3. An interbody spacer comprising:

vertebral bodies;

first orifices defined through the top surface; and

first and second orifices is in open communication thereby defining afirst channel

surface; and

communication with the second channel, wherein a center portion of at least one of the first and second channel defines a cylindrical profile and upper and lower portions of the channel define a frusto-conical profile.

4. The interbody spacer of claim 3, wherein a diameter of each frusto-conical profile

decreases in a direction towards the center of the channel such that the diameter of each

frusto-conical profile at a center portion of the channel is less than a diameter of the

cylindrical profile.

5. An interbody spacer comprising:

vertebral bodies;

first orifices defined through the top surface; and

surface; and

communication with the second channel,

wherein a center portion of at least one of the first and second channel defines a

cylindrical profile and the upper and lower portions of the channel define an hourglass

profile.

6. An interbody spacer comprising:

vertebral bodies;

first orifices defined through the top surface; and

surface; and

communication with the second channel,

spherical profile and the upper and lower portions of the channel define an hourglass profile.

7. The interbody spacer of any preceding claim, wherein the body portion is formed

from powder processed using Selective Laser Powder Processing.