U.S. patent application number 12/002467 was filed with the patent office on 2008-05-01 for vertebral body and disc space replacement devices.
Invention is credited to Bret M. Berry, Eric C. Lange.
Application Number | 20080103602 12/002467 |
Document ID | / |
Family ID | 33309443 |
Filed Date | 2008-05-01 |
United States Patent
Application |
20080103602 |
Kind Code |
A1 |
Berry; Bret M. ; et
al. |
May 1, 2008 |
Vertebral body and disc space replacement devices
Abstract
A vertebral replacement body device for supporting adjacent
vertebrae includes a connecting member having an upper member and a
lower member engaged thereto at opposite ends thereof. The members
can be restrained relative to one another to resist axial, rotation
and/or lateral displacement. The vertebral replacement body device
can have a chamber extending therethrough for fusion of the
supported vertebrae.
Inventors: |
Berry; Bret M.; (Cordova,
TN) ; Lange; Eric C.; (Germantown, TN) |
Correspondence
Address: |
KRIEG DEVAULT LLP
ONE INDIANA SQUARE, SUITE 2800
INDIANAPOLIS
IN
46204-2709
US
|
Family ID: |
33309443 |
Appl. No.: |
12/002467 |
Filed: |
December 17, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10400837 |
Mar 27, 2003 |
7309358 |
|
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12002467 |
Dec 17, 2007 |
|
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10103237 |
Mar 21, 2002 |
6758862 |
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10400837 |
Mar 27, 2003 |
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Current U.S.
Class: |
623/17.16 |
Current CPC
Class: |
A61F 2/44 20130101; A61F
2220/0025 20130101; A61F 2002/30062 20130101; A61F 2002/30125
20130101; A61F 2002/30593 20130101; A61F 2002/30784 20130101; A61F
2002/30426 20130101; A61F 2230/0069 20130101; A61F 2310/00029
20130101; A61F 2002/2835 20130101; A61F 2310/00359 20130101; A61F
2002/30235 20130101; A61F 2/28 20130101; A61F 2002/30153 20130101;
A61F 2230/0019 20130101; A61F 2/4455 20130101; A61F 2002/305
20130101; A61F 2002/30133 20130101; A61F 2310/00017 20130101; A61F
2230/0006 20130101; A61F 2230/0023 20130101; A61F 2230/0034
20130101; A61F 2002/30156 20130101; A61F 2002/30616 20130101; A61F
2002/30187 20130101; A61F 2230/0015 20130101; A61F 2310/00179
20130101; A61F 2002/3023 20130101; A61F 2310/00023 20130101; A61F
2220/0033 20130101; A61F 2002/30367 20130101; A61F 2002/30601
20130101; A61F 2310/00329 20130101; A61F 2002/30878 20130101; A61F
2210/0004 20130101; A61F 2230/0008 20130101; A61F 2/442 20130101;
A61F 2002/3049 20130101; A61F 2002/30113 20130101 |
Class at
Publication: |
623/017.16 ;
606/061 |
International
Class: |
A61F 2/44 20060101
A61F002/44; A61B 17/58 20060101 A61B017/58 |
Claims
1-85. (canceled)
86. A device positionable in a spinal column, comprising: a body
having a first height between a first end and an opposite second
end, said body including a side wall extending between said first
and second ends, said side wall extending around a chamber, wherein
said first end defines a first bearing surface extending around
said chamber that defines a single opening into said chamber and
said second end defines an end wall that defines a second bearing
surface across said chamber, wherein said first height is sized to
extend between adjacent vertebrae of the spinal column with the
first end and the second end in contact with endplates of the
adjacent vertebrae.
87. The device of claim 86, further comprising an element at said
first end that cover said single opening.
88. The device of claim 86, wherein said end wall includes a number
of openings extending therethrough in communication with said
chamber.
89. The device of claim 88, wherein said side wall includes a
number of openings extending therethrough in communication with
said chamber.
90. The device of claim 86, wherein said bearing surface includes a
convex curvature structured to fit the concave curvature of an
adjacent vertebral endplate when the device is positioned between
the vertebrae.
91. The device of claim 86, wherein said first bearing surface and
said end wall define a kidney-shape.
92. The device of claim 91, wherein said kidney shape is defined by
a convexly curved portion of said side wall and a concavely curved
portion of said sidewall, said concavely curved portion being
opposite said convexly curved portion.
93. The device of claim 86, further comprising: a member including
a second body extending along a longitudinal axis between a third
end and an opposite fourth end, wherein said third end includes a
third bearing surface extending therearound and an extension
extending axially from said third end with said third bearing
surface extending around said extension, and further wherein said
extension is sized for receipt in said chamber of said body with
said first bearing surface in contact with said third bearing
surface.
94. The device of claim 86, wherein said single opening is
non-circular.
95. A device positionable in a spinal column, comprising: a body
having a first height between a first end and an opposite second
end, said body including a side wall extending between said first
and second ends, said side wall extending around a chamber, wherein
said first end defines a first bearing surface extending around
said chamber that defines a non-circular opening into said chamber
and said second end defines an end wall that defines a second
bearing surface across said chamber, wherein said first height is
sized to extend between adjacent vertebrae of the spinal column
with the first end and the second end in contact with endplates of
the adjacent vertebrae.
96. The device of claim 95, wherein said first bearing surface
defines no more than one opening into said chamber.
97. The device of claim 96, wherein said end wall includes a number
of openings extending therethrough in communication with said
chamber.
98. The device of claim 97, wherein said side wall includes a
number of openings extending therethrough in communication with
said chamber.
99. The device of claim 95, wherein said bearing surface includes a
convex curvature structured to fit the concave curvature of an
adjacent vertebral endplate when the device is positioned between
the vertebrae.
100. The device of claim 95, wherein said first bearing surface and
said end wall define a kidney-shape.
101. The device of claim 100, wherein said kidney-shape is defined
by a convexly curved portion of said side wall and a concavely
curved portion of said sidewall, said concavely curved portion
being opposite said convexly curved portion.
102. The device of claim 95, further comprising: a member including
a second body extending along a longitudinal axis between a third
end and an opposite fourth end, wherein said third end includes a
third bearing surface extending therearound and an extension
extending axially from said third end with said third bearing
surface extending around said extension, and further wherein said
extension is sized for receipt in said chamber of said body with
said first bearing surface in contact with said third bearing
surface.
103. A vertebral replacement device, comprising: a first member
extending along a longitudinal axis between a first end and an
opposite second end, wherein said second end is positionable
against an endplate of a vertebra and said first member defines a
chamber extending between said first end and said second end; and a
second member extending along said longitudinal axis between a
first end and a second end of said second member, wherein one of
said first member and said second member includes a number of
recesses radially dispersed about said first end thereof, said
recesses each extends axially into first end and also each extends
along a radius that extends from a center of said one of said first
and second members, wherein the other of said first member and said
second member includes a number of radially dispersed projections
that each extends axially from said first end and also each extends
along a radius that extends from a center of said other of said
first and second members, wherein said first member is positioned
on said second member with said projections and recesses in radial
interdigitation to resist displacement of said first and second
members relative to one another.
104. The device of claim 103, further comprising a third member
extending along said longitudinal axis between a first end of said
third member that is positionable against an endplate of a second
vertebra and an opposite second end of said third member, wherein
one of said second member and said third member includes a number
of recesses radially dispersed about said second end thereof, said
recesses each extends axially into second end and also each extends
along a radius that extends from a center of said one of said
second and third members, wherein the other of said second member
and said third member includes a number of radially dispersed
projections that each extends axially from said second end thereof
and also each extends along a radius that extends from a center of
said other of said second and third members, wherein said third
member is positioned on said second member with said projections
and recesses in radial interdigitation to resist displacement of
said second and third members relative to one another.
105. The device of claim 104, wherein said second member includes a
chamber extending therethrough, said chambers being aligned with
said first member and said third member stacked on said second
member.
106. The device of claim 103, wherein said recesses and said
projections are V-shaped.
107. The device of claim 106, wherein said V-shapes each include a
peak and said peaks extend along said radius extending from said
center of said respective first member and said second member.
108. The device of claim 103, further comprising an engaging member
extending between said first and second members to axially secure
said first and second members to one another.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. patent
application Ser. No. 10/400,837 filed on Mar. 27, 2003, and issuing
as U.S. Pat. No. 7,309,358, which is a continuation-in-part
application of U.S. patent application Ser. No. 10/103,237 filed on
Mar. 21, 2002, and issued as U.S. Pat. No. 6,758,862, each of which
is incorporated herein by reference in its entirety.
BACKGROUND
[0002] The present invention is directed to devices for replacement
of one or more vertebral bodies and/or one or more disc spaces
between vertebrae of a spinal column.
[0003] The repair and reconstruction of bony structures is
sometimes accomplished by directly fixing adjacent bony structures
to each other, such as by a plate. In other instances, bone growth
inducing material can be introduced between the adjacent bony
structures, which over time results in a solid bony connection. In
some instances, the adjacent bony structures are not sufficiently
strong to maintain their patency as the bone heals or the bone
grows between the adjacent structures through the bone growth
inducing material. In these instances, mesh structures or cages
have been provided to engage the adjacent bony structures to
provide additional stability. The cages are generally hollow and
can be configured to contact the harder cortical bone of the
adjacent bony structures. The hollow portion of the cages can be
filled with bone growth inducing material.
[0004] There remains a need for improved devices for replacing one
or more vertebral bodies and/or one or more disc spaces in a spinal
column. The present invention is directed to satisfying these
needs, among others.
DESCRIPTION OF THE FIGURES
[0005] FIG. 1 is a perspective view of a vertebral replacement
device according to one embodiment.
[0006] FIG. 2 is an exploded perspective view of the vertebral
replacement device of FIG. 1.
[0007] FIG. 3 is a side elevation view of the vertebral replacement
device of FIG. 1 in partial section to illustrate the
interconnection between adjacent members of the device.
[0008] FIG. 4 is an elevational view of an engaging member
comprising a portion of the vertebral body member of the device of
FIG. 1.
[0009] FIG. 5 is an end view of the vertebral replacement device of
FIG. 1.
[0010] FIG. 6 is a perspective view of a member comprising a
portion of the vertebral replacement device of FIG. 1.
[0011] FIG. 7 is an elevation view of the member of FIG. 6.
[0012] FIG. 8 is an elevational view of the vertebral replacement
device of FIG. 1 positioned in the spinal column between two
vertebrae.
[0013] FIG. 9 is an elevational view of one of the members
comprising a portion of the vertebral replacement device of FIG. 1
positioned in a spinal disc space between adjacent vertebrae.
[0014] FIG. 10 is a perspective view of another embodiment
vertebral replacement device.
[0015] FIG. 11 is an exploded perspective view of another
embodiment vertebral replacement device.
[0016] FIG. 12 is a perspective view of a vertebral replacement
device according to another embodiment.
[0017] FIG. 13 is an exploded perspective view of the vertebral
replacement device of FIG. 12.
[0018] FIG. 14 is a perspective view of a vertebral replacement
device according to another embodiment.
[0019] FIG. 15 is an exploded perspective view of the vertebral
replacement device of FIG. 14.
[0020] FIG. 16 is a perspective view of a vertebral replacement
device according to another embodiment.
[0021] FIG. 17 is an exploded perspective view of the vertebral
replacement device of FIG. 16.
[0022] FIG. 18 is a partially exploded perspective view of a
vertebral replacement device according to another embodiment.
[0023] FIG. 19 is a perspective view of a vertebral replacement
device according to another embodiment.
[0024] FIG. 20 is a partially exploded perspective view of a
vertebral replacement device according to another embodiment.
[0025] FIG. 21 is an exploded perspective view of a vertebral
replacement device according to another embodiment.
[0026] FIG. 22 is a perspective view of another embodiment disc
replacement member usable with a vertebral replacement device.
[0027] FIG. 23 is another perspective view of the disc replacement
member of FIG. 22.
[0028] FIG. 24 is a perspective view of another embodiment
vertebral replacement device.
[0029] FIG. 25 is a perspective view of another embodiment
vertebral replacement device.
[0030] FIG. 26 is a perspective view of another embodiment
vertebral replacement device.
[0031] FIGS. 27A and 27B are side views of another embodiment
vertebral replacement device.
[0032] FIG. 28 is a perspective view of another embodiment
vertebral replacement device.
[0033] FIG. 29 is an exploded perspective view of the vertebral
replacement device of FIG. 28.
[0034] FIG. 30 is an exploded perspective view of another
embodiment vertebral replacement device.
[0035] FIG. 31 is an exploded perspective view of another
embodiment vertebral replacement device.
[0036] FIG. 32 is an exploded perspective view of another
embodiment vertebral replacement device.
[0037] FIGS. 33 and 33A are a plan and section view, respectively,
of a first member comprising another embodiment vertebral
replacement device.
[0038] FIGS. 34 and 34A are a plan and section view, respectively,
of a second member engageable to the first member of FIGS. 33 and
33A.
[0039] FIG. 35 is a perspective view of a vertebral replacement
device comprising the first and second members of FIGS. 33 and
34.
[0040] FIG. 36 is an exploded view of another embodiment vertebral
replacement device.
[0041] FIGS. 37 and 37A are a plan view and elevation view,
respectively, of another embodiment vertebral replacement
device.
[0042] FIG. 38 is a plan view of a member of another embodiment
vertebral replacement device.
[0043] FIG. 39 is a plan view of a member of another embodiment
vertebral replacement device.
[0044] FIG. 40 is a plan view of a member of another embodiment
vertebral replacement device.
[0045] FIG. 41 is a plan view of a member of another embodiment
vertebral replacement device.
[0046] FIG. 42 is a plan view of a member of another embodiment
vertebral replacement device.
[0047] FIG. 43 is a plan view of a member of another embodiment
vertebral replacement device.
[0048] FIG. 44 is a plan view of a member of another embodiment
vertebral replacement device.
[0049] FIG. 45 is a plan view of a member of another embodiment
vertebral replacement device.
[0050] FIG. 46 is a plan view of a member of another embodiment
vertebral replacement device.
DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS
[0051] For the purpose of promoting an understanding of the
principles of the invention, reference will now be made to the
illustrated embodiments thereof and specific language will be used
to describe the same. It will nevertheless be understood that no
limitation of the scope of the invention is thereby intended. Any
such alterations and further modifications in the invention, and
any such further applications of the principles of the invention as
described herein are contemplated as would normally occur to one
skilled in the art to which the invention relates.
[0052] The present invention relates to devices for replacing one
or more vertebral bodies in the spinal column and/or one or more
disc spaces between adjacent vertebrae. It is contemplated that the
replacement devices will support adjacent ones of the intact
vertebrae during fusion thereof. It is further contemplated that
one or more members of the vertebral replacement devices can be
positioned in a disc space between adjacent vertebrae for
supporting the adjacent vertebrae during fusion thereof.
[0053] In one embodiment, the device can employ current mesh or
cage-type devices for engagement with adjacent bony structures,
although other types of bone supporting devices are also
contemplated. The vertebral replacement device can have a tubular
form with a hollow chamber extending therethrough. The adjacent
vertebrae are supported by opposite ends of the device and the
chamber can be filled with bone growth inducing or osteogenetic
material. The ends of the device can include flattened plateau-like
end surfaces that can be formed at the junction between bars
defining the mesh wall structure of the device.
[0054] In one embodiment, the vertebral replacement device includes
a connecting member and an upper attached to an upper end of the
connecting member and a lower member attached to a lower end of the
connecting member. Each of the members can have a generally kidney
bean cross-sectional shape in the plane transverse to the central
axis of the assembled device. Other cross-sectional shapes are also
contemplated, including circular, racetrack-shaped, rectangular,
square, oval, D-shaped, triangular, boomerang, banana, or other
polygonal shape. Each of the upper and lower members can include an
interior chamber. The connecting member can also include an
interior chamber that generally aligns with the interior chambers
of the upper and lower members engaged thereto.
[0055] In one embodiment, the upper and lower members can be
fabricated from a tubular mesh having apertures through its wall.
One example of a tubular mesh is provided in U.S. Pat. No.
5,897,556, which is incorporated herein by reference in its
entirety. The connecting member can also be fabricated from a
tubular mesh. Further forms contemplate that the upper and lower
members and connecting member can be a tubular body with solid
walls or wall structure including one or more openings.
[0056] In one embodiment, the upper and lower members can be
telescopically and non-rotatably engaged with the connecting
member. The connecting member includes an upper extension and a
lower extension extending therefrom. The upper and lower extensions
are in the form of substantially continuous rings extending around
the respective ends of the vertebral body or connecting member.
Other forms for the upper and lower extensions are also
contemplated. The upper and lower extensions are received in the
interior chamber of the respective upper or lower members when the
upper and lower members are engaged to the connecting member. In
another embodiment, extensions are provided on the upper and lower
members, and these extensions are received in an interior chamber
or opening at respective ends of the connecting member.
[0057] Each of the upper and lower extensions, and each of the
chambers of the upper and lower members, can have a non-circular
cross-section and interface to prevent relative rotation between
the connecting member and the upper or lower member engaged
thereto.
[0058] In one embodiment, the upper and lower extensions of the
connecting member each include an engaging member which can be
flexed inwardly as the respective upper or lower member is placed
around the respective extension of the connecting member. The
engaging member fits into an opening or aperture in the inner wall
surface of the respective upper and lower members to axially secure
the respective upper and lower members to the connecting
member.
[0059] The vertebral replacement device can be made from any
biocompatible material, including synthetic or natural autograft,
allograft or xenograft tissues, and can be resorbable or
non-resorbable in nature. Examples of tissue materials include hard
tissues, connective tissues, demineralized bone matrix and
combinations thereof. Further examples of resorbable materials are
polylactide, polyglycolide, tyrosine-derived polycarbonate,
polyanhydride, polyorthoester, polyphosphazene, calcium phosphate,
hydroxyapatite, bioactive glass, and combinations thereof. Further
examples of non-resorbable materials are non-reinforced polymers,
carbon-reinforced polymer composites, PEEK and PEEK composites,
shape-memory alloys, titanium, titanium alloys, cobalt chrome
alloys, stainless steel, ceramics and combinations thereof and
others as well.
[0060] Any suitable osteogenetic material or composition is
contemplated for placement within the chambers defined by the
members of the vertebral replacement device. Such osteogenic
material includes, for example, autograft, allograft, xenograft,
demineralized bone, synthetic and natural bone graft substitutes,
such as bioceramics and polymers, and osteoinductive factors. Where
bony material is placed within the chambers of the members of the
vertebral replacement device, the material can be pre-packed into
the hollow chambers before the device is implanted, or can be
pushed through the plurality of wall openings after the device is
in position in the spinal column. A separate carrier to hold the
materials within the chambers of the device can also be used. These
carriers can include collagen-based carriers, bioceramic materials,
such as BIOGLASS.RTM., hydroxyapatite and calcium phosphate
compositions. The carrier material can be provided in the form of a
sponge, a block, folded sheet, putty, paste, graft material or
other suitable form. Moreover, the osteogenetic compositions
contained within the vertebral replacement device can comprise an
effective amount of a bone morphogenetic protein, transforming
growth factor .beta.1, insulin-like growth factor 1,
platelet-derived growth factor, fibroblast growth factor, LIM
mineralization protein (LMP), and combinations thereof or other
therapeutic or infection resistant agent, held within a suitable
carrier material.
[0061] In FIGS. 1-2, a vertebral replacement device 10 includes a
connecting member 12, an upper member 30, and a lower member 40.
Device 10 is illustrated as having a tubular form that extends
along a longitudinal axis 11 and defines a chamber extending
therethrough along axis 11. Bone growth can occur through this
chamber for fusion between the vertebral bodies supported at each
end of device 10.
[0062] Connecting member 12 includes a body 14 extending between an
upper end 19 and an opposite lower end 21. Connecting member 12
further includes an upper extension 18 and a lower extension 23.
Connecting member 12 has an inner wall surface 13 (FIG. 5) that
defines a chamber 16 extending between and opening at the outer
ends of the extensions 18, 23. Each of the extensions 18, 23
extends outwardly from the respective end 19, 21 of body 14 and
around chamber 16. End surface 15 extends around upper extension
18, and end surface 17 extends around lower extension 23. In the
illustrated embodiment, extensions 18, 23 are substantially
continuous rings extending from their respective end 19, 21. Other
embodiments contemplate other forms for the extensions, such as,
for example, a series of two or more flexible engaging members
(such as engaging member 20 discussed below) or rigid engaging
members.
[0063] The wall of body 14 includes a number of triangular
apertures 22 which extend through the wall and communicate with
chamber 16. Other shapes for apertures 22 are also contemplated,
including non-circular shapes such as a square, diamond, oval
and/or rectangular shapes, circular shapes, and/or polygonal
shapes. The wall of body 14 also includes a number of holes 24
extending at least partially therethrough. Holes 24 can be threaded
or otherwise sized and/or configured for engagement with one or
more insertion instruments (not shown.)
[0064] Referring further to FIGS. 3-5, the substantially continuous
wall of each of the extensions 18, 23 is interrupted by an engaging
member 20. Only engaging member 20 for upper extension 18 is
illustrated, it being understood that lower extension 23 can also
be provided with an identical or similar engaging member. Engaging
members 20 secure upper member 30 and lower member 40 to respective
ends of connecting member 12, resisting axial dislocation of upper
member 30 and lower member 40 away from connecting member 12 along
axis 11. Engaging members 20 can also resist axial rotation of
upper and lower members 30, 40 relative to connecting member 12
about axis 11. Other embodiments contemplate that more than one
engaging member 20 is provided in the wall of one or both of the
extensions 18, 23. Further embodiments contemplate that wall of one
or both of the extensions 18, 23 is not substantially continuous,
but rather is continuous or includes a number of discrete wall
portions sufficiently spaced and sized about body 14 of connecting
member 12 for engagement with upper and lower members 30, 40.
[0065] Engaging member 20 includes a projection or engaging portion
52 and a stem 50 connected or integrally formed with end surface 15
of body 14. Stem 50 has a reduced thickness to allow engaging
member 20 to deflect inwardly in response to a force applied to
engaging portion 52. Engaging portion 52 projects outwardly from
stem 50 and has a triangular shape tapering from an engaging
surface 54 to an upper end 56. Other configurations for engaging
member 20 are also contemplated. For example, engaging member 20
can be provided with an engaging portion 52 in the form of a
partially spherical or rounded nub, a receptacle, rectangular or
polygonal shaped tab or projection. Engaging portion 52 can also
correspond to the shape the aperture 22 in which it is received.
Engaging member 20 can also be a snap ring, collet, bayonet lock,
or surface irregularity that resists axial movement of the engaged
upper member 30 and lower member 40 away from connecting member 12
along axis 11.
[0066] Referring also to FIGS. 6-7, upper and lower members 30, 40
are illustrated as being identical, although it is also
contemplated that upper member 30 and lower member 40 can be
provided with different configurations and/or sizes. With respect
to FIGS. 6 and 7, only upper member 30 will be further described,
it being understood that lower member 40 can be provided with
identical features.
[0067] Upper member 30 includes a body 32 extending between an
upper end 33 and a lower end 35. Body 32 has a height 82 between
the upper and lower ends 33, 35. Height 82 can be selected so that
upper member 30 fits within an intervertebral disc space between
adjacent vertebrae. Upper end 33 and lower end 35 can be sloped to
converge toward one another and form a height 86 opposite height
82. The sloped ends 33, 35 allow upper member 30 to restore and/or
conform to the natural inclination between the adjacent endplates
of the vertebral bodies. It is further contemplated that ends 33,
35 can be parallel to one another.
[0068] Body 32 has an inner wall surface 37 defining a chamber 34
that extends between and opens at ends 33, 35. As shown in FIG. 5,
body 32 has an outer surface 39 that defines a kidney-shaped cross
section transverse to longitudinal axis 11. Other cross-sectional
shapes are also contemplated, including, for example, circular
cross-sections and non-circular cross-sections, such as oval,
triangular, square, rectangular, polygonal, boomerang shaped,
D-shaped, or racetrack shaped cross-sections. In the illustrated
embodiment, connecting member 12 has the same cross-sectional shape
as the upper and lower members 30, 40 to provide a vertebral
replacement body device of uniform cross-sectional shape and size
along its height.
[0069] Body 32 defines a number of triangular apertures 36
extending at least partially therethrough in communication with
chamber 34, and a number of circular holes 38 extending at least
partially therethrough from the exterior surface of body 32. Holes
38 or the other holes can be threaded or otherwise sized and/or
configured for engagement with one or more insertion
instruments.
[0070] Body 32 further includes a number of bearing surfaces 60
spaced around first end 32 and bearing surfaces 62 spaced around
second end 35. Adjacent ones of each of the bearing surfaces 60 are
separated from one another by V-shaped recesses 64. Adjacent ones
of each of the bearing surfaces 62 are separated from one another
by V-shaped recesses 66. Bearing surfaces 60, 62 are planar and
provide a number of plateau-like, generally flat bearing surfaces
spaced about the respective end of body 32. Bearing surfaces 60, 62
have a trapezoidal shape in the illustrated embodiment, although
other shapes are also contemplated. In the illustrated embodiment,
ten such bearing surfaces 60, 62 are provided at each end of body
32. It is also contemplated that fewer than ten or more than ten
bearing surfaces could be provided. It is further contemplated that
each end of body 32 could be provided with a single, continuous
bearing surface extending around chamber 34.
[0071] The plateau-like bearing surfaces 60, 62 provide a surface
area about the ends of body 32 for bearing support of the adjacent
vertebral endplate and to resist subsidence of body 32 into the
vertebrae. The plateau-like bearing surfaces 60, 62 provide surface
area contact between the end of body 32 and the adjacent endplate,
providing frictional resistance to body 32 sliding or twisting
relative to the adjacent vertebral endplate.
[0072] Upper member 30 and lower member 40 are connected to
respective ends of connecting member 12 to provide vertebral
replacement body device 10. Upper member 30 is advanced over upper
extension 18 so that upper extension 18 extends into chamber 34.
Engaging member 20 flexes inwardly as inner wall surface 37 of body
32 passes along engaging portion 52. Engaging portion 52 is
configured to reside within one of the apertures 36 extending into
the wall of body 32 from chamber 34. When engaging portion 52 and
the respective aperture 36 are aligned, engaging member 20 returns
towards its pre-insertion position with engaging portion 52
residing in the respective aperture 36. This engages upper member
30 to connecting member 12, resisting movement of upper member 30
away from connecting member 12 along axis 11. It is further
contemplated engaging surface 54 engages the adjacent lower surface
of the respective aperture 36 to provide a positive seat between
bearing surface 15 of connecting member 12 and bearing surfaces 62
about end 33 of upper member 30. Lower member 40 is secured to
lower extension 23 in a similar manner.
[0073] Bearing surfaces 62 at lower end 35 of upper member 30 bear
against end surface 15 extending about upper extension 18 of
connecting member 12. This bearing relationship transmits the
spinal column load from upper member 30 to connecting member 12.
The bearing surfaces of the lower member 40 similarly bear against
end surface 17 extending about lower extension 23 of connecting
member 12. The end surfaces 15, 17 at the ends of body 14 and the
adjacent bearing surfaces of the upper and lower members 30, 40 do
not interdigitate. This bearing relationship eliminates stress
concentrations and shifting of the components of device 10 that
might result from improperly aligned interdigitating surfaces.
[0074] Axial rotation of upper member 30 and lower member 40
relative to connecting member 12 is resisted by the interface
between upper and lower extensions 18, 23 and the respective inner
wall surface of the upper and lower members 30, 40. In the
illustrated embodiment, extensions 18, 23 have a non-circular
shape, such as the kidney shape shown in FIG. 5. Similarly, the
inner wall surface 37 of upper member 30 and also the inner wall
surface of lower member 40 have a non-circular shape sized to
receive in form fitting engagement the respective upper or lower
extension 18, 23. This non-circular form fitting engagement
prevents rotation of upper member 30 and lower member 40 relative
to connecting member 12.
[0075] Device 10 can be used to replace a vertebra that has been
removed from the spinal column segment using known techniques.
Device 10 is assembled by securing upper member 30 to one end of
connecting member 12 and securing lower member 40 to the other end
of connecting member 12. This provides a vertebral replacement
device 10 that has an overall height that is equal to the sum of
the heights 80 of body 14, height 82 of upper member 30, and height
84 of lower member 40 (FIG. 3.)
[0076] As shown in FIG. 8, the vertebral replacement device 10 can
be placed between vertebra 70 and vertebra 74 after removal of
vertebra 72. Replacement of more than one vertebra is also
contemplated. Although not required, it is contemplated that height
80 could be representative of that of the removed vertebra and
heights 82, 84 could be representative of the heights of the
respective disc spaces between the removed vertebra 72 and the
remaining vertebrae 70, 74. Also shown in FIG. 8 is a stabilization
construct 150 engaged to and extending between vertebrae 70 and 74
to support and stabilize the spinal column segment before, during
and, if construct 150 is non-resorbable and left in the patient,
after fusion. Stabilization construct 150 can be a rod system,
plate system or artificial ligament system. It is further
contemplated that stabilization system could be attached to any
portion of vertebrae 70 and 74, including the anterior,
antero-lateral, lateral, postero-lateral or posterior portions.
[0077] It is also contemplated that heights 82 and 84 could be
identical or different, and that the ends of upper and lower
members 30, 40 could be provided with the same or differing angles
of inclination. It is further contemplated that device 10 can
comprise a kit having a number of upper members 30 and lower
members 40 of various sizes and heights 82, 84. A kit could also
include a number of connecting members 12 of various sizes and
heights 80. Such a kit would provide the surgeon flexibility in
selecting the appropriately size and height for members of a device
10 based on conditions encountered in surgery.
[0078] FIG. 9 illustrates placement of one of the upper or lower
members 30, 40 in disc space 76 between adjacent vertebrae 70, 72
to function as an interbody fusion device. Engagement of
stabilization construct to vertebrae 70 and 72 is also
contemplated.
[0079] It is also contemplated that connecting member 12 could be
provided with one end configured to bear against a vertebral
endplate, and that only one of the upper and lower members 30, 40
is engaged to the other end of connecting member 12. The assembled
device could then be placed between adjacent vertebrae with an end
of connecting member 12 and an end of the selected upper or lower
member 30, 40 in contact with the adjacent vertebral endplates.
[0080] In FIG. 10 there is provided an alternate embodiment
vertebral replacement device 100. Device 100 includes upper member
30 and lower member 40 engaged at opposite ends of a vertebral body
or connecting member 102, which can be similar to connecting member
12 discussed above. Connecting member 102 does not include upper
and lower extensions extending from ends 104 and 105. To secure
upper member 30 and lower member 40 to connecting member 102, a
sleeve 112 is provided around connecting member 102 that has an
upper end 114 overlapping upper member 30 and a lower end 115
overlapping lower member 40.
[0081] Sleeve 112 can be provided with engaging members 117, 118 in
the form of projections, engaging members, tabs or the like on its
inner wall surface. Engaging members 117, 118 engage apertures 36,
46 or other receptacle or detent in the outer wall surfaces of
upper member 30 and lower member 40, respectively. Engaging members
could also be provided to engage apertures 106 or other receptacle
or detent in connecting member 102. So engaged, sleeve 112 resists
axial movement of upper member 30 and lower member 40 relative to
connecting member 102.
[0082] It is further contemplated that rotation of upper member 30
and lower member 40 relative to connecting member 102 could be
prevented by a non-circular, telescoping interface between the
members such as discussed above. In another embodiment, rotation of
upper member 30 and lower member 40 relative to connecting member
102 could be prevented by the engagement of sleeve 112 with the
upper and lower members 30, 40 and, if so configured, with
connecting member 102. In yet a further form of the embodiment of
FIG. 10, the connecting member 102 could be integral with sleeve
member 112 to provide upper and lower bearing surfaces within
sleeve 112 for support of upper member 30 and lower member 40
thereon.
[0083] Referring now to FIG. 11, another embodiment vertebral
replacement device 210 is shown. Device 210 includes a vertebral
replacement or connecting member 212 having a body 214 extending
between an upper end 219 and a lower end 221. Upper end 219
includes an upper extension 218 having an end surface 215
therearound. Extension 218 extends around a bearing surface 216 at
the upper end of chamber 220. Bearing surface 216 is positioned
below end surface 215 in chamber 220. Second end 217 similarly
includes an extension 223 having an end surface 217, and a bearing
surface (not shown) at the lower end of chamber 220 below end
surface 217.
[0084] A first disc replacement or upper member 230 includes a body
232 having an upper end 233 and a lower end 235. Body 232 extends
around a chamber 234. A second disc replacement or lower member 240
includes a body 242 having a lower end 243 and an upper end 245.
Body 242 extends around a chamber 244. Lower member 240 includes an
inset wall 248 extending around chamber 244, and a bearing surface
250 extending around body 242 below inset wall 248. Upper member
230 similarly includes an inset wall 238 and a bearing surface (not
shown) extending around body 232 above inset wall 238.
[0085] When assembled, inset wall 238 of upper member 230 is
received in chamber 220 of connecting member 212 with extension 218
extending around inset wall 238. Similarly, inset wall 248 of lower
member 240 is received in chamber 220 of connecting member 212 with
extension 223 extending around inset wall 248. It contemplated that
end surface 215 can contact the bearing surface extending around
inset wall 238, and that end surface 217 can contact bearing
surface 250 extending around inset wall 248. Additionally or
alternatively, the lower end of inset wall 238 can contact bearing
surface 216 in chamber 220 at the upper end of connecting member
212, and the upper end of inset wall 248 can contact the bearing
surface (not shown) in chamber 220 at the lower end of connecting
member 212.
[0086] Connecting member 212 and/or upper and lower members 230,
240 could be provided with engaging members or a sleeve such as
discussed above to prevent axial and/or rotational movement of
upper and lower members 230, 240 relative to connecting member 212
when device 210 is assembled. In a further embodiment, connecting
member 212 does not include the upper bearing surface 216 and the
lower bearing surface in chamber 220 since extensions 218, 223 are
not provided on connecting member 212. In this embodiment, inset
walls 238 and 248 are received in chamber 220 at the respective end
of connecting member 212, and end surfaces 215, 217 contact
respective ones of the bearing surfaces extending around inset
walls 238, 248.
[0087] Referring now to FIGS. 12 and 13, another embodiment
vertebral replacement device 310 is shown. Device 310 includes a
vertebral replacement or connecting member 312 having a body 314
extending between an upper end 319 and a lower end 321. Upper end
319 includes a pair of upper extensions 318 extending from a
bearing surface 316 at the upper end of chamber 320. Lower end 321
similarly includes extensions 323 and a bearing surface (not shown)
at the lower end of chamber 320.
[0088] A first disc replacement or upper member 330 includes a body
332 having an upper end 333 and a lower end 335. Body 332 extends
around a chamber 334. A second disc replacement or lower member 340
includes a body 342 having a lower end 343 and an upper end 345.
Body 342 extends around a chamber 344. Lower member 340 includes
receptacles 348 sized and shaped to slidingly receive respective
ones of the extensions 323 therein. Similarly, upper member 330
includes receptacles 338 formed in lowed end 335 sized and shaped
to slidingly receive extensions 318 therein. Receptacles 338, 348
can be provided at each end of members 330, 340 so that either end
can be secured to connecting member 312.
[0089] It is contemplated that extensions 318, 323 can include an
enlarged outer end that provides a trapezoidal shape so that when
positioned in the correspondingly shaped receptacle 338, 348 in
dovetail fashion vertical displacement of members 330, 340 relative
to connecting member 312 is resisted. Accordingly, upper and lower
members 330, 340 are positioned on connecting member 312 by
laterally sliding the upper and lower members 330, 340 onto
extensions 318, 323. Other shapes for extensions 318, 323 and
receptacles 338, 348 are also contemplated, including hook-shaped,
triangular shaped, or other irregular shape that provides vertical
securement. Extensions 318, 323 also resist rotation of the members
330, 340 relative to connecting member 312.
[0090] In order to prevent lateral displacement of upper member 330
in the direction between extensions 318 and also to provide further
vertical engagement, an upper coupling member 350 is provided to
secure upper member 330 to connecting member 312. Similarly, a
lower coupling member 360 is provided to secure lower member 340 to
connecting member 312. Upper member 330 includes a wall portion 336
that is enlarged and provided with a through-hole 337. Upper
coupling member 350 is positionable in hole 337 to engage
connecting member 312, vertically and laterally securing upper
member 330 thereto. Similarly, lower member 340 includes a wall
portion 346 that is enlarged and provided with a through-hole 347.
Lower coupling member 360 is positionable in hole 347 to engage
connecting member 312, vertically and laterally securing lower
member 340 thereto.
[0091] Coupling members 350, 360 can be provided in the form of
screws that threading engage respective ones of the passages 325,
327 extending into connecting member 312. Passages 325, 327 can be
formed in an enlarged wall portion 326 of connecting member 312. In
one embodiment, passages 325, 327 include a blind end and do not
extend through connecting member 312. It is contemplated that
passages 325, 327 can be threaded to threadingly engage coupling
members 350, 360. Holes 337, 347 can be threaded or non-threaded.
Other embodiments contemplate that passages 325, 327 form a single
continuous passage through connecting member 312. It is further
contemplated that wall portions 326, 336, 346 need not be enlarged
relative to the remaining portion of the wall of the members 312,
330, 340, but rather can form part of a wall of uniform thickness.
In addition, bearing surfaces 316, 321 include a smooth surface
profile thereabout, although other surface profiles are also
contemplated. The upper and lower bearing surfaces of members 330,
340 can be configured as discussed above with respect to members
30, 40.
[0092] Referring now to FIGS. 14 and 15, another embodiment
vertebral replacement device 410 is shown. Device 410 includes a
disc replacement or connecting member 412 having a body 414
extending between an upper end 419 and a lower end 421. Upper end
419 includes a pair of upper receptacles 418 extending into a
bearing surface 416 at the upper end of chamber 420. Lower end 421
similarly includes receptacles 423 and a bearing surface (not
shown) at the lower end of chamber 420.
[0093] A first vertebral body or upper member 430 includes a body
432 having an upper end 433 and a lower end 435. Body 432 extends
around a chamber 434. A second vertebral body or lower member 440
includes a body 442 having a lower end 443 and an upper end 445.
Body 442 extends around a chamber 444. Lower member 440 includes
extensions 448 sized and shaped for sliding receipt in respective
ones of the receptacles 423. Similarly, upper member 430 includes
extensions 438 extending from lower end 435 thereof sized and
shaped for sliding receipt in receptacles 418 of connecting member
412. It is contemplated that extensions 438, 448 can be configured
as discussed above with respect to vertebral replacement device
310. Extensions 438, 448 can be omitted from upper end 433 of upper
member 430 and lower end 445 of lower member 440 to provide
sufficient bearing surface area at each end for contact with an
adjacent vertebral endplate.
[0094] Coupling members 450, 460 prevent lateral displacement and
also provide vertical engagement as discussed above with respect to
coupling members 350, 360. Accordingly, upper member 430 includes a
wall portion 436 that is provided with a through-hole 437. Upper
coupling member 450 is positionable in hole 437 to engage
connecting member 412, vertically and laterally securing upper
member 430 thereto. Similarly, lower member 440 includes a wall
portion 446 that is provided with a through-hole 447. Lower
coupling member 460 is positionable in hole 447 to engage
connecting member 412, vertically and laterally securing lower
member 440 thereto.
[0095] Coupling members 450, 460 can be provided in the form of
screws that threadingly engage passages 425 extending through
connecting member 412. Passage 425 can be formed in wall portion
426 of connecting member 412. In one embodiment, passage 425 can be
separated into separate portions with blind ends so that passage
425 does not extend through connecting member 412.
[0096] In the embodiment of FIGS. 14 and 15, connecting member 412
is provided with a height between ends 419, 421 that approximates
the height of a vertebral disc space. Accordingly, connecting
member 412 can be used in an unstacked configuration as a disc
space replacement member. Bearing surfaces 416 at ends of
connecting member 412 can be configured to engage the vertebral
endplates, such as discussed above with respect to device 10 and
upper and lower members 30, 40. It is also contemplated that
connecting member 412 can be used with only one of the upper and
lower members 430, 440. Upper and lower members 430, 440 can be
provided with a height that allows the assembled vertebral
replacement device 410 to replace one or more vertebral bodies and
one or more disc spaces removed from a portion of the spinal
column.
[0097] Referring now to FIGS. 16 and 17, another embodiment for
vertebral replacement device 410 is shown with another embodiment
engagement arrangement between connecting member 412 and members
430, 440. In this embodiment, upper member 430 is provided with a
number of extensions 438 and lower member 440 is provided with a
number of extensions 448. Extensions 438 are positionable in
receptacles 418 formed in upper bearing surface 416 of connecting
member 412. Extensions 448 can be positioned in corresponding
receptacles 423 formed in the lower bearing surface of connecting
member 412. Extensions 438, 448 and receptacles 418, 423 are
configured so that members 430, 440 can be end-loaded onto
connecting member 412, and thus do not resist displacement of
members 430, 440 away from connecting member 412. Extensions 438,
448 are radially dispersed about the center of members 430, 440 to
provide torsional and lateral stability for members 430, 440 when
positioned in the correspondingly positioned receptacles 418, 423
of connecting member 412. Coupling members 450, 460 provide axial
stability for the assembled device 410.
[0098] Referring to FIG. 18 there is shown vertebral replacement
device 1610 including a connecting member 1612, an upper member
1630 and a lower member 1640. Connecting member 1612 includes an
upper end 1619 having a number of projections radially spaced about
an upper bearing surface thereof. Connecting member 1612 includes a
lower end 1621 including a number of projections 1622 radially
spaced about a lower bearing surface thereof. As discussed above
with respect to vertebral replacement device 10, connecting member
1612 can include extensions at the upper and lower ends thereof
such as shown with extension 1623, to telescopically receive the
adjacent upper and lower members 1630, 1640. An engaging member
1620 at each of the upper and lower extensions includes an engaging
portion that engages the adjacent upper and lower member 1630, 1640
to axially secure the adjacent upper and lower members 1630, 1640
to connecting member 1612.
[0099] Each of the upper and lower members 1630, 1640 include
radially spaced recesses 1636, 1646 formed in lower surface 1635 of
body 1632 and upper surface 1645 of body 1642, respectively.
Recesses 1636, 1646 are sized and shaped to receive corresponding
ones of the projections 1617, 1622 when device 1610 is assembled.
Recesses 1636, 1646 also extend along a radius extending from the
center of the corresponding upper and lower member 1630, 1640 in
order to receive the respective projections 1617, 1622. The radial
interdigitation of the radially spaced projections and recesses
provides resistance to displacement of the members 1630, 1640
relative to connecting member 1612 as a result of torsional
loading. Further, the radial spacing of the projections universally
about the center axis of device 10 provides resistance to
displacement of the members 1630, 1640 relative to connecting
member 1612 as a result of lateral loading applied from any
direction. In the illustrated embodiment, projections 1617, 1622
are V-shaped, and the peak of the v-shape extends along a radius
extending from the center of connecting member 1612.
[0100] As shown in FIG. 19, the vertebral replacement devices can
include modular components or members so that more than three
members can be stacked one upon the other to provide a vertebral
replacement device of the desired overall height. For example,
vertebral replacement device 600 includes an upper member 30, a
connecting member 12, and a first lower member 40. Members 12, 30
and 40 are illustrated as including a configuration as discussed
above with respect vertebral replacement device 10, or can include
any configuration discussed herein. A second connecting member 602,
which can be identical to connecting member 12, can be coupled to
the lower end of first lower member 40. A second member 604, which
can be identical to upper and/or lower members 30, 40, is coupled
to the lower end of connecting member 602. Accordingly, any number
of components can be stacked one upon another and axially secured
as discussed herein to provide a vertebral replacement device of
desired overall height.
[0101] In the embodiment illustrated in FIG. 19, connecting members
12, 602 can each be provided with a height that approximates the
height of a vertebral body. Upper and lower members 30, 40, 604 can
approximate the height of a spinal disc space. Thus, vertebral
replacement device 600 can be employed in a corpectomy procedure in
which a pair of vertebrae are removed along with the spinal disc
spaces between the remaining intact vertebrae.
[0102] Referring now to FIG. 20, another embodiment vertebral
replacement device 1700 includes a first disc replacement or upper
member 1730 and second disc replacement or lower member 1740
engaged at opposite ends of a vertebral body or connecting member
1712. Connecting member 1712 can be identical to upper and lower
members 1730, 1740. In the illustrated embodiment, connecting
member 1712 does not include upper and lower extensions or
engagement members extending from ends 1714 and 1715. Ends 1714,
1715 are adapted to bearing against the endplates of adjacent
vertebrae when connecting member 1712 is positioned in isolation in
the disc space between vertebrae.
[0103] Connecting member 1712 can be employed in a vertebral
replacement device 1700 by securing at least one of the members
1730, 1740 at one end thereof. A sleeve 1720 is provided that is
positionable in the chambers of connecting member 1712, upper
member 1730 and lower member 1740 and slidable relative thereto.
Sleeve 1720 includes an engaging member 1722 formed in its wall at
the opposite ends thereof. Engaging member 1720 can be configured
as discussed above with respect to engaging member 20 discussed
above. Engaging member 1722 can include an engaging portion that
includes a lateral projection or the like to resiliently engage an
opening in the inner wall surface of upper and lower members 1730,
1740 to axially secure upper and lower members 1730, 1740 thereto
with connecting member 1712 therebetween.
[0104] Connecting member 1712 and/or one or both of the members
1730, 1740 can be provided with a height adapted to replace a
vertebral body. Sleeve 1720 can include a length between its
opposite ends adapted to secure two, three or four or more members
to one another axially. Sleeve 1720 can also include a non-circular
cross-section that non-rotatably and slidingly accepts a similarly
shaped non-circular chamber of the members 1712, 1730, 1740. Sleeve
1720 can be provided with a hollow interior opening at each end to
permit fusion therethrough. It is further contemplated that sleeve
1720 can be solid and comprise a bone graft or other suitable bone
replacement material. Sleeve 1720 could also be a solid body with a
number of holes formed therethough to permit fusion.
[0105] Referring to FIG. 21, another embodiment vertebral
replacement device 1800 includes a first disc replacement or upper
member 1830 and second disc replacement or lower member 1840
engaged at opposite ends of a vertebral body or connecting member
1812. Connecting member 1812 can be identical in size and shape to
upper and lower members 1830, 1840 as illustrated, or can be
different in size and shape. Members 1812, 1830, 1840 can be
employed when unstacked in disc space replacement procedures or in
corpectomy procedures when stacked.
[0106] To secure upper member 1830 and lower member 1840 to
connecting member 1812, a first sleeve 1820 is provided that is
positionable in the chambers of connecting member 1812 and upper
member 1830, and a second sleeve 1825 is provided that is
positionable in the chambers of connecting member 1812 and lower
member 1840. Sleeves 1820, 1825 include each include engaging
members formed in the wall thereof at opposite ends thereof. For
example, engaging member 1822 is shown at the lower end of sleeve
1820, and engaging member 1827 is shown at the lower end of sleeve
1825. The engaging members at the upper ends of sleeves 1820, 1822
are not shown. The engaging members can be provided as discussed
above with respect to engaging member 20. Engaging members 1822,
1827 can include an engaging portion that includes a lateral
projection or the like that engages an opening in the inner wall
surface of connecting member 1812 and the adjacent upper and lower
members 1830, 1840 to axially secure upper and lower members 1830,
1840 thereto.
[0107] Sleeves 1820, 1825 can include a length to secure two
members to one another axially. An additional sleeve can be
provided for each additional member to be added to the end of upper
and/or lower members 1830, 1840. A two member stack can be formed
with a single sleeve 1820, 1825. Sleeves 1820, 1825 can also
include a non-circular cross-section that non-rotatably and
slidingly accepts a similarly shaped non-circular chamber of the
members 1812, 1830, 1840. Sleeves 1820, 1825 can be provided with a
hollow interior opening at each end to permit fusion therethrough.
It is further contemplated that sleeves 1820, 1825 can be solid and
comprise a bone graft or other suitable bone replacement material.
Sleeves 1820, 1825 could also be a solid body with a number of
holes formed therethough to permit fusion.
[0108] FIGS. 22 and 23 illustrate another embodiment for the upper
and lower disc replacement members that comprise the vertebral
replacement devices discussed herein. Disc replacement member 1900
can be coupled to the upper or lower end of a connecting member,
such as connecting member 12 discussed above, or received over the
end of a sleeve, such as sleeves 1720, 1820 discussed above. Disc
replacement member 1900 includes a side wall 1910 extending between
a first end 1902 and an opposite second end 1904. First end 1902
includes an opening in communication with chamber 1906. Second end
1904 includes an upper wall 1908 having a plurality of openings
1912 in communication with chamber 1906.
[0109] Side wall 1910 includes a number of openings 1916 in
communication with chamber 1906. Openings 1916 can be circular,
triangular, or include any other suitable configuration. One or
more of the openings 1916 can be adapted to engage an insertion
instrument. First end 1902 includes a bearing surface 1914
extending about chamber 1906 to bear against a support surface of a
connecting member, or against the endplate of an adjacent vertebra.
Upper wall 1908 forms an upper surface adapted to bear against the
endplate of an adjacent vertebra. Upper wall 1908 can be flat, or
provided with a convex curvature adapted to fit with the concave
curvature of an adjacent vertebral endplate. In the illustrated
embodiment, upper wall 1908 and bearing surface 1914 define a
kidney-shape, although other shapes are also contemplated,
including circular, oval, square, rectangular, polygonal, and any
other non-circular shape.
[0110] Referring now to FIGS. 24-26, there is shown another
embodiment vertebral replacement device 510. Each of the vertebral
replacement devices 510 is generally identical, and includes a
connecting member 512, an upper member 530 and a lower member 540.
However, the devices include overall heights that vary from one to
the other, and each of the devices includes members having heights
that vary from one to the other. For example, device 510 in FIG. 24
includes an overall height 580 formed by members 512, 530, 540,
each of which have approximately the same height 581. Height 581
can be adapted for each of the members 512, 530, 540 to be used in
a spinal disc space in an unstacked arrangement for interbody
fusion.
[0111] Vertebral replacement device 510 in FIG. 25 includes an
overall height 582 adapted for corpectomy procedures in which a
vertebral body and associated spinal discs have been removed. In
FIG. 25, upper and lower members 530, 540 each include a height
583, and connecting member 512 includes a height 584. Height 583 is
greater than height 584. Vertebral replacement device 510 in FIG.
26 includes an overall height 586 adapted for corpectomy procedures
in which a vertebral body and associated spinal discs have been
removed. In FIG. 26, upper and lower members 530, 540 each include
a height 587 that is greater than height 583 and height 584. Thus,
when unstacked, the various heights provided by members 512, 530,
540 provide the surgeon a range of heights from which to select a
disc space replacement member for an interbody fusion procedure. It
is further contemplated members of various heights 582, 583, 584,
and 587 can be provided in a kit, and the surgeon can mix and match
selected members and secure the selected members to one another to
provide a vertebral replacement device of overall height sized to
provide the desired fit in the space left by one or more removed
vertebrae.
[0112] For each of the embodiments in FIGS. 24-26, connecting
member 512 includes a body 514 extending between an upper end 519
and a lower end 521. Upper member 530 includes a body 532 extending
between and upper end 533 and a lower end 535. Body 532 defines a
chamber 534 extending between and opening at upper end 533 and
lower end 535. Lower member 540 includes a body 542 extending
between and upper end 543 and a lower end 545. Body 542 defines a
chamber 544 extending between and opening at upper end 543 and
lower end 545. Connecting member 512 can be provided with a chamber
(not shown) extending between upper end 519 and lower end 521 in
communication with chambers 534, 544.
[0113] Connecting member 512 include a number of elongated ridges
523 extending along its upper end surface adjacent upper end 519,
and a number of elongated ridges 525 along the end surface adjacent
lower end 521. Upper member 530 includes a number of elongated
ridges 531 along its upper surface adjacent upper end 532, and a
number of elongated ridges 539 extending along its end surface
adjacent lower end 535. Similarly, lower member 540 includes a
number of elongated ridges 541 along its lower surface adjacent
lower end 545, and a number of ridges 549 extending along its upper
surface adjacent upper end 543. Adjacent ones of the elongated
ridges 523, 539 and ridges 525, 549 interdigitate when upper and
lower members 530, 540 are stacked on connecting member 512 and
resist movement of the members relative to one another transversely
to the ridges.
[0114] To resist axial displacement and displacement of the members
relative to one another in the direction of the ridges, coupling
members 550, 560 extend through a hole extending through the wall
of upper member 530 between ends 533, 535. Coupling members 550,
560 engage aligned passages in connecting member 512. Lower member
540 can be similarly secured with coupling members (not shown) that
extend through holes in lower member 540 and into aligned passages
of connecting member 512.
[0115] When assembled as a stack, vertebral replacement device 510
can be inserted in the space between vertebrae. Connecting member
512 can be provided with anterior openings 516 along a convexly
curved wall portion of body 514 to facilitate attachment of an
insertion instrument for insertion of device 510 in anterior
approach to the disc space. Oblique openings 517 can be provided in
body 514 to facilitate attachment of an instrument for inserting
vertebral replacement device 510 in an anterior oblique approach.
Lateral openings 518 in the side wall portions of body 532
facilitate attachment of an instrument for inserting vertebral
replacement device 510 in a lateral approach. Openings 516, 517,
518 can be any one or combination of threaded, non-threaded,
slotted or combinations thereof, or other suitable configuration,
for attachment of an insertion instrument. It is further
contemplated that upper and lower members 530, 540 can also be
provided with similarly positioned anterior, oblique or lateral
openings for attachment of an insertion instrument.
[0116] Various windows can be provided in the lateral walls of
upper and lower members 530, 540 to facilitate bone growth and
visualization of the interior of chambers 534, 544. For example,
upper member 530 includes windows 537 extending through lateral
wall portions of body 532 in communication with chamber 534.
Similarly, lower member 547 includes windows 547 extending through
the lateral wall portions of body 542 in communication with chamber
544.
[0117] Vertebral replacement devices 510 are illustrated with a D
shape extending therealong. When implanted, the convexly curved
wall portions of bodies 514, 532, 542 can be oriented anteriorly.
The opposite posterior wall portion of bodies 514, 532, 542 is
relatively flat and posteriorly oriented when implanted. The
anterior portions of the bodies 532, 542 of upper and lower members
530, 540, and the anterior portion of body 514 of connecting member
512, each include a wall thickness that allows the openings for
coupling members 550, 560 to be formed therethrough. The increased
thickness wall portions also provide additional bearing surface
area at the ends of device 510 to support the vertebrae.
[0118] Referring now to FIGS. 27A and 27B, various configurations
for the ridges along the upper and lower surfaces of member 530 and
connecting member 512 are shown. Lower member 540 can also be
provided with ridge configuration. In the illustrated embodiment,
upper member 530 includes ridges 531, 539 having a swept-back
profile. For example, each ridge 531 includes a peak 591 formed at
the intersection of a first wall 593 and a second wall 595. Second
wall 595 is sloped to facilitate insertion in the direction of
arrow 590, and first wall 593 is more vertically oriented so that
ridges 531 bite into the adjacent endplate upon movement or
attempted movement in the direction opposite arrow 590. Ridges 539
include a similar profile so that either surface of member 530 can
contact the adjacent vertebral endplate.
[0119] The swept back profile of ridges 531, 539 also facilitates
engagement between the stacked members 530, 512. In the illustrated
embodiment, the upper and lower bearing surface of member 530 are
angled relative to one another at angle 552, and the upper and
lower surfaces of connecting member 512 are angled relative to one
another at angle 554. When stacked upon one another, the device
forms an overall angle 556 between the upper surface of member 530
and the lower surface of connecting member 512. In the illustrated
embodiment, the reduced height wall portion of member 530 is
positioned adjacent greater height wall portion of connecting
member 512. Accordingly, the overall angle 556 of device 510 is
less than the angles 554, 552. The more vertically oriented wall
portions of the ridges bear against one another, providing
resistance to the adjacent inclined surfaces sliding relative to
one another.
[0120] In FIG. 27B, upper member 530 includes ridges 531 oriented
having gradually sloped wall portions 595 oriented in a direction
opposite that of the gradually sloped wall portions of lower ridges
539. The upper and lower bearing surfaces of member 530 are
oriented at an angle 558, and the upper and lower bearing surfaces
of member 512 are oriented at angle 554. The reduced height wall
portions of members 530, 512 are positioned adjacent one another,
forming overall angle 556 between the upper surface of member 530
and lower surface of members 512 that is greater than angle 554 and
angle 558. By providing ridges 531, 539 with orientations in the
opposite direction, upper member can be flipped over and stacked on
connecting member 512 to provide a lesser overall angle 556. This
reduces the number of members required in a kit to provide the
surgeon a number of options in arranging the stacked members to
provide the desired angulation between the upper and lower end
surfaces.
[0121] Referring now to FIGS. 28-29, another embodiment vertebral
replacement device 610 includes a connecting member 612, an upper
member 630, and a lower member 640. Connecting member 612 includes
an upper extension 618 and a lower extension 623 extending from
upper and lower ends 619 and 621, respectively. Upper member 630
includes a bore 636 extending between the upper and lower surfaces
thereof, and lower member 640 includes a bore 646 extending between
upper and lower surfaces thereof. Upper extension 618 is
positionable in bore 636 of upper member 630, and lower extension
623 is positionable in bore 646 of lower member 540. Openings 638,
648 extend through a wall of upper and lower members 630, 640 and
communicate with bores 636, 646.
[0122] When assembled, coupling members 650, 660 extend through
openings 638, 648, respectively, and engage the adjacent extension
618, 623 in bores 636, 646. In the illustrated embodiment,
extensions 618, 623 are integral with connecting member 612. The
coupling members resist axial displacement of upper and lower
members 630, 640 away from connecting member 612. When stacked one
upon the other, chamber 634 of upper member 630 and chamber 644 of
lower member 640 align with chamber 614 of connecting member 612.
The aligned chambers provide an avenue for bony fusion of the
supported vertebrae.
[0123] The adjacent surfaces of upper member 630 and connecting
member 612, and the adjacent surfaces of connecting member 612 and
lower member 640, can be provided with interdigitating ridges to
resist lateral and rotational displacement. Extensions 618, 623 can
also resist lateral displacement of the members relative to one
another. Resistance to displacement from torsional forces can be
provided by, for example, the interdigitating ridges on the
adjacent faces of the stacked members as illustrated. Other
embodiments contemplate that members 612, 630, 640 are provided
without interdigitating ridges or surfaces. Additional coupling
members or fasteners could be provided through the stacked members,
or a non-rotatable, telescoping interface between members of the
stack could be employed, to provide torsional, lateral and/or axial
stability. In another embodiment, extensions 618, 623 can extend
from one or both of the upper member 630 and lower member 640, and
positioned in bores formed in connecting member 612 and secured
thereto with coupling members.
[0124] In FIG. 30, another embodiment vertebral replacement device
710 includes an upper member 730 and a lower or connecting member
712. Upper and lower members 712, 730 can include a D-shaped body
with the convexly curved wall anteriorly oriented between the
adjacent vertebrae. Chambers 714, 734 are alignable when stacked to
provide a passage for bony fusion. Other shapes and configurations
for members 714, 734 are also contemplated as discussed herein.
[0125] An extension 718 is provided in the form of a rod that
extends through bore 736 of upper member 730 and bore 716 of
connecting member 712. Coupling members 750, 760 are positionable
in openings 738, 718, respectively and engage extension 718 in
bores 736, 716 to secure members 730, 712 thereto and to resist
axial and lateral displacement of the members 730, 712 relative to
one another. Members 712, 730 can be provided with interdigitating
ridges, a non-rotatable telescoping interface, and/or other
fasteners to secure members 712, 730 to one another. In another
embodiment, extension 718 can include a non-circular cross-section,
and is received in correspondingly shapes bores 716, 736 to resist
rotational displacement of members 712, 730 relative to one
another. In still another embodiment, extensions 718 can be
provided with a length that allows three or more members to stacked
and secured therealong.
[0126] In FIG. 31, another embodiment vertebral replacement device
810 is shown with a connecting member 812 and upper and lower
members 830, 840. Connecting member 812 and upper and lower members
830, 840 can include a D-shaped body with the convexly curved wall
anteriorly oriented between the adjacent vertebrae. Chambers 814,
834, 844 are alignable when stacked to provide a passage for bony
fusion. Other shapes and configurations for members 812, 830, 840
are also contemplated as discussed herein.
[0127] Connecting member 812 includes first and second passages
816, 818 extending between upper and lower bearing surfaces of
connecting member 812. First and second passages 816, 818 are sized
and shaped to receive first and second extensions 836, 838 of upper
member 830 when upper member 830 is stacked thereon. The pair of
extensions 836, 838 resist lateral and torsional movement of upper
member 830 relative to connecting member 812. Similarly, lower
member 840 includes first and second extensions 846, 848
positionable in first and second passages 816, 818 of connecting
member 812 from a lower surface thereof.
[0128] A coupling member 850 is positionable in receptacles 832,
820 and 842 of members 830, 812, 840, respectively, when stacked
one upon the other. Each of the receptacles 832, 820, 842
communicate with the exterior perimeter of members 830, 812, 840,
and include a hole 833, 813, 843 alignable with holes 861, 871,
881, respectively, provided along coupling member 850. Engagement
members 860, 870, 880, in the form of set screws or other suitable
fastener, are positioned in the aligned holes and engage coupling
member 850 to respective ones of the members 830, 812, 840.
Coupling member 850 can be recessed in receptacles 832, 820, 840 so
that it does not protrude from members 812, 830, 840. Coupling
member 850 resists axial displacement of members 830, 840 away from
connecting member 812.
[0129] In FIG. 32, another embodiment vertebral replacement device
910 is shown with a connecting member 912 and upper and lower
members 930, 940. Connecting member 912 and upper and lower members
930, 940 can include a D-shaped body with the convexly curved wall
anteriorly oriented between the adjacent vertebrae. Chambers 914,
934, 944 are alignable when stacked to provide a passage for bony
fusion. Other shapes and configurations for members 912, 930, 940
are also contemplated as discussed herein.
[0130] Connecting member 912 includes first and second passages
916, 918 extending between upper and lower bearing surfaces of
connecting member 912. First and second passages 916, 918 are sized
and shaped to receive first and second extensions 936, 938 of upper
member 930 when upper member 930 is stacked thereon. The pair of
extensions 936, 938 resist lateral and torsional movement of upper
member 930 relative to connecting member 912. Similarly, lower
member 940 includes first and second extensions 946, 948
positionable in first and second passages 916, 918 of connecting
member 912 from a lower surface thereof.
[0131] A coupling member 950 is positionable in receptacles 932,
920, 942 of members 930, 912, 940, respectively, when stacked one
upon the other. Each of the receptacles 932, 920, 942 can include a
hole alignable with holes provided along coupling member 950.
Engagement members 960, 970, 980, in the form of set screws or
other suitable fastener, are positioned in the aligned holes and
engage coupling member 950 to respective ones of the members 930,
912, 940. Coupling member 950 can be recessed in receptacles 932,
920, 942 so that it does not protrude from members 930, 912,
940.
[0132] Additional coupling members, such as coupling member 955,
can be secured in other receptacles formed about the perimeter of
members 930, 912, 940 with engagement members 965, 975, 985,
respectively. For example, lateral receptacles 933, 917, 943 can be
provided in the opposite side walls of the perimeter of members
930, 912, 940, respectively, to receive coupling members. Oblique
receptacles 935, 921, 945 can be provided in the obliquely oriented
walls of the perimeter of members 930, 912, 940, respectively, to
receive coupling members. Multiple coupling members 950, 955 can be
spaced about and secured to the perimeter of members 930, 912, 940
to provide lateral, torsional and axial stability of the stacked
members 930, 912, 940.
[0133] Referring now to FIGS. 33-35, another embodiment stackable
vertebral replacement device 1010 is shown with connecting member
1012 and upper and lower members 1030, 1040. Connecting member 1012
and upper and lower members 1030, 1040 can include a D-shaped body
with the convexly curved wall anteriorly oriented in the space
between adjacent vertebrae. Chambers 1014, 1034 and the chamber
(not shown) of lower member 1040 are alignable when stacked to
provide a passage for bony fusion. Other shapes and configurations
for members 1012, 1030, 1040 are also contemplated as discussed
herein.
[0134] Referring to FIGS. 33 and 33A, connecting member 1012
includes a first receptacle 1016 and a second receptacle 1018
extending between and opening at upper surface 1020 and lower
surface 1022 of member 1012. First receptacle 1016 includes a first
locking portion 1017 formed therein body 1013, and second
receptacle 1018 includes a second locking portion 1019 formed
therein.
[0135] Referring to FIGS. 34-34A, upper member 1030 includes a
first extension 1036 and a second extension 1038 extending from
lower surface 1031. First extension 1036 includes an engagement
member 1037 at a distal end thereof, and second extension 1038
includes an engagement member 1039 at a distal end thereof. First
extension 1036 is positionable in first receptacle 1016 so that
engagement member 1037 interlocks with first locking portion 1017.
Similarly, second extension 1038 is positionable in second
receptacle 1018 so that engagement member 1039 interlocks with
second locking portion 1019.
[0136] In the illustrated embodiment, bearing surfaces 1033, 1035
of engagement members 1037, 1039 bear against surfaces 1021, 1023
of receptacles 1016, 1018, respectively, to resist axial
displacement. The interlocking engagement between the engagement
members 1037, 1039 and receptacles 1016, 1018 resists axial
displacement of upper member 1030 relative to connecting member
1012. The pair of spaced extensions 1036, 1038 resist lateral and
torsional displacement of upper member 1030 relative to connecting
member 1012. Lower member 1040 can similarly be provided with a
pair of extensions having engagement members that are positionable
in receptacles 1016, 1018 from lower surface 1012 of connecting
member to secure lower member 1040 to connecting member 1012.
[0137] Upper member 1030 can be secured to connecting member 1012
to provide a two member stack. Lower member can be secured below
connecting member 1012 to provide a three member stack. Upper and
lower members 1030, 140 can be provided with receptacles opposite
extensions 1036, 1038 to allow stacking and securement of four or
more members from one another. For example, as shown in FIGS. 34
and 34A, upper member 1030 includes a first receptacle 1026 having
a first locking portion 1027, and a second receptacle 1028
including a second locking portion 1029. A second upper member 1030
can be stacked on upper member 1030 with extensions 1036, 1038
locked in receptacles 1026, 128. Lower member 1040 can be similarly
configured with receptacle in its lower surface to facilitate
stacking and securement of additional lower members 1040
thereto.
[0138] Additional axial securement of the stacked members 1012,
1030, 1040 can provided by coupling member 1050 positionable in any
one or combination of receptacles 1016 in the perimeter of the
walls of the members, such as discussed above with respect to
vertebral replacement device 910. The coupling members 1050 and/or
outer receptacles 1016 are not required for axial securement of
members 1030, 1040 to connecting member 1012, however, since
extensions 1036, 1038 can provide axial securement.
[0139] Referring now to FIG. 36, another embodiment vertebral
replacement device 1110 is shown. Vertebral replacement device 1110
includes an upper member 1130 and a lower member 1140 stackable on
opposite sides of connecting member 1112. Connecting member 1112
and upper and lower members 1130, 1140 can include a kidney-shaped
body with the convexly curved wall anteriorly oriented in the space
between adjacent vertebrae and the concavely curved posterior wall
posteriorly oriented. Upper member 1130 includes a number of
chambers 1134 therethrough to facilitate bone growth and bony
fusion. Connecting member 1112 and lower member 1140 can be
provided with similarly sized and shaped chambers alignable with
chambers 1134 when members 1130, 1112 and 1140 are stacked one upon
the other. Other shapes and configurations for members 1112, 1130,
1140 are also contemplated as discussed herein.
[0140] Upper member 1130 includes a first extension 1136 and a
second extension 1138 extending from a lower surface thereof.
Extensions 1136, 1138 can be integrally formed with upper member
1130. Lower member 1140 includes a first extension 1146 and a
second extension 1148 extending from an upper surface thereof.
Extensions 1146, 1148 can be integrally formed with lower member
1140. Connecting member 1112 includes receptacles 1116, 1118
extending between upper and lower surfaces thereof to receive
corresponding ones of the extensions 1136, 1138 of upper member
1130 and extensions 1146, 1148 of lower member 1140. The interface
between the extensions and receptacles resists lateral and
torsional movement of upper and lower members 1130, 1140 relative
to connecting member 1112. In the illustrated embodiment, the
extensions include non-circular cross-sections that are received in
the correspondingly shaped receptacles.
[0141] The adjacent upper and lower surfaces of the stacked members
1130, 1112, 1140 can include interdigitating ridges to further
resist lateral and axial movement. Still other embodiments
contemplate the adjacent surfaces can be planar, or can include a
telescoping, non-rotatable stacking arrangement between the
adjacent members. Axial displacement of the stacked members can be
resisted by coupling members engaged along the perimeter of the
stacked members, by one or more coupling members extending through
all or a portion of the stacked members, or other suitable coupling
arrangement.
[0142] It is further contemplated that one of the upper or lower
members 1130, 1140 can be stacked with connecting member 1112 to
provide a two member stack. Upper and lower members 1130, 1140 can
also be provided with receptacles 1137, 1139, for example, to
receive extensions from a second member to provide a stack of four
or more members. The height and/or angulation between the upper and
lower ends of the vertebral replacement device 1110 can thus be
adjusted as necessary for disc space replacement or vertebral body
replacement procedures. It is also contemplated that connecting
member 1112 and/or upper and lower members 1030, 1040 can be
provided with a height that enables it to be used in isolation as a
disc space replacement device.
[0143] In FIGS. 37-46, various shapes for the disc space
replacement and/or vertebral body members are illustrated. The
members of FIGS. 37-46 can be used in isolation as a disc space
replacement member, or provided in a set of multiple members and
stacked one upon the other for vertebral replacement procedures.
The members can be provided any one or combination of engagement
features discussed herein such that when the members are stacked
any one or combination of lateral, torsional and axial displacement
of the members is resisted.
[0144] In FIGS. 37 and 37A, member 1200 includes a D-shaped body
having a first end wall 1204, opposite side walls 1208, 1210, and a
second end wall 1206. A chamber 1216 is defined between the upper
and lower ends of body 1202. Passages 1212, 1214 can extend between
the upper lower ends of body 1202 and can be adapted for bone
growth, or to receive coupling members or extensions to secure a
number of members 1200 in a stack. Second end wall 1206 has a
reduced height relative to first end wall 1204 and side walls 1208,
1210 such that body 1202 provides U-shaped upper and lower bearing
surfaces 1218, 1220. In one application, first end wall 1204 is
oriented anteriorly in the spinal column and side walls 1208, 1210
are laterally spaced to provide bilateral support of the supported
vertebra on respective sides of the central axis of the spinal
column. First end wall 1204 can include a convexly curved outer
surface to fit with the endplate anatomy at the anterior portion of
the supported vertebrae. First end wall 1204 also includes a linear
inner surface providing end wall 1204 with sufficient thickness for
passages 1212, 1214.
[0145] In FIG. 38, another embodiment member 1230 includes a
D-shaped body 1232 having a first end wall 1234 with a convexly
curved outer surface and linear inner surface, opposite side walls
1238, 1240, and a second end wall 1236. A chamber 1246 is defined
between the upper and lower ends of body 1232. Passages 1242, 1244
can extend between the upper lower ends of body 1232 and can be
adapted for bone growth, or to receive coupling members or
extensions to secure a number of members 1230 in a stack. Second
end wall 1236 has a reduced height relative to first end wall 1234
and side walls 1238, 1240 such that body 1232 provides U-shaped
upper and lower bearing surfaces, such as discussed above with
respect to member 1200. Second end wall 1236 is offset anteriorly
relative the adjacent ends of side walls 1238, 1240, and extends
between side walls 1238, 1240 to provide lateral stability
thereto.
[0146] In FIG. 39, another embodiment member 1260 includes a
U-shaped body 1262 having a first end wall 1264 with a convexly
curved outer surface and linear inner surface, and opposite side
walls 1268, 1270 that open posteriorly when member 1260 is
positioned in the disc space with first end wall 164 anteriorly
positioned. A chamber 1276 is defined between the upper and lower
surfaces of body 1262 for receipt of bone growth material, a bone
graft, or other device or material therein. The open posterior wall
further facilitates positioning of body 1262 adjacent the posterior
elements of the spinal column without impinging thereon. Passages
1272, 1274 can extend between the upper lower ends of body 1262
through first end wall 1264 and can be adapted for bone growth, or
to receive coupling members or extensions to secure a number of
members 1260 in a stack.
[0147] In FIG. 40, another embodiment member 1300 includes a
U-shaped body 1302 having a first end wall 1304 with convexly
curved outer and inner surfaces, and opposite side walls 1308, 1310
that open posteriorly when member 1300 is positioned in the disc
space and first end wall 1304 is anteriorly positioned. The open
posterior portion facilitates positioning of body 1302 adjacent the
posterior elements of the spinal column without impinging thereon.
A chamber 1316 is defined between the upper and lower ends of body
1300 for receipt of bone growth material, a bone graft, or other
device or material therein.
[0148] In FIG. 41, another embodiment member 1330 includes a
D-shaped body 1332 having a first end wall 1334 with a convexly
curved outer surface and linear inner surface, opposite side walls
1338, 1340, and opposite second end wall portions 1336, 1337. A
chamber 1346 is defined between the upper and lower ends of body
1332. Passages 1342, 1344 can extend between the upper lower ends
of body 1332 through first end wall 1334, and can be adapted for
bone growth, or to receive coupling members or extensions to secure
a number of members 1330 in a stack. Second end wall portions 1336,
1337 include a space therebetween, and facilitate in maintaining a
bone graft or other device or material in chamber 1346. The open
second wall further facilitates positioning of body 1332 adjacent
the posterior elements of the spinal column without impinging
thereon.
[0149] In FIG. 42, another embodiment member 1360 includes a
semi-circular shaped body 1362 having a first end wall 1364 with a
convexly curved inner and outer surfaces and convexly curved side
walls 1368, 1370 that open posteriorly when member 1360 is
positioned in the disc space with first end wall 1364 anteriorly
oriented. A chamber 1376 is defined between the upper and lower
ends of body 1360 for receipt of bone growth material, a bone
graft, or other device or material therein. Chamber 1376 is open
posteriorly of body 1362. The open posterior wall further
facilitates positioning of body 1362 adjacent the posterior
elements of the spinal column.
[0150] In FIG. 43, another embodiment member 1400 includes a body
1402 including a wall 1403 that defines a chamber 1416 having a
U-shape. Wall 1403 includes a first end wall portion 1404 with
convexly curved inner and outer surfaces. Wall 1403 further
includes opposite side wall portions 1408, 1410 extending generally
parallel to one another. Wall 1403 further includes a second end
wall including a first portion 1406 and a second portion 1407
extending from respective ones of the side wall portions 1410,
1408. Wall 1403 further includes a middle portion 1414 extending
into chamber 1416 from first and second portions 1406, 1407 that
defines a recess 1418 opening between portions 1406, 1407. The open
recess facilitates positioning of member 1400 adjacent the
posterior elements of the spinal column without impinging thereon.
The number of wall portions provide bearing surface area for
supporting the vertebral endplates and a chamber to facilitate
fusion of the vertebrae through member 1400.
[0151] In FIG. 44, another embodiment member 1430 includes a body
1432 including a first end wall 1434 having a convexly curved outer
surface. Passages 1442, 1444 extend through first end wall 1434
between the upper lower ends of body 1432 and can be adapted for
bone growth, or to receive coupling members or extensions to secure
a number of members 1430 in a stack. Body 1432 further includes
opposite side walls 1438, 1440 extending generally parallel to one
another. Body 1432 includes a second end wall 1436 having a central
convexly curved recess 1437 at a central strut 1447. Central strut
1447 extends between central recess 1437 and first end wall 1434.
Central strut 1447 divides body 1432 into a first chamber portion
1445 and a second chamber portion 1446. Recess 1437 facilitates
positioning of body 1432 adjacent the posterior elements of the
spinal column without impinging thereon.
[0152] In FIG. 45, another embodiment member 1460 includes a body
1462 including a first end wall 1464 having a convexly curved outer
surface. Body 1462 further includes opposite side walls 1469, 1470
extending generally parallel to one another. Body 1462 includes a
second end 1466 having a central recess 1467. A pair of medial
walls 1468, 1471 extend anteriorly from second end wall 1466 along
central recess 1467. Side wall 1470 and medial wall 1471 define a
first chamber 1484, and side wall 1469 and medial wall 1468 define
a second chamber 1486. An enlarged recess portion 1472 is located
adjacent first end wall 1464 and in communication with narrower
portion of recess 1467. Enlarged portion 1472 can receive material
to facilitate bone growth, or a coupling member or extensions to
secure a number of members 1460 in a stack. Recess 1467 facilitates
positioning of body 1462 adjacent the posterior elements of the
spinal column without impinging thereon.
[0153] In FIG. 46, another embodiment member 1500 includes a body
1502 including a first end wall 1504 having a convexly curved outer
surface. Passages 1512, 1514 can extend between the upper lower
ends of body 1502 and can be adapted for bone growth, or two
receive coupling members or extensions to secure a number of
members 1500 in a stack. Body 1502 further includes opposite side
walls 1508, 1510 extending generally parallel to one another. Body
1502 includes a second end wall 1506 having a central recess 1507.
A pair of medial walls 1517, 1518 extend from second end wall 1506
along central recess 1507 to first end wall 1504. Side wall 1510
and medial wall 1517 define a first chamber 1524, and side wall
1508 and medial wall 1518 define a second chamber 1526. Recess 1507
facilitates positioning of body 1502 adjacent the posterior
elements of the spinal column without impinging thereon.
[0154] While the invention has been illustrated and described in
detail in the drawings and foregoing description, the same is to be
considered as illustrative and not restrictive in character. All
changes and modifications that come within the spirit of the
invention are desired to be protected.
* * * * *