U.S. patent application number 16/450495 was filed with the patent office on 2019-10-31 for spinal implant and assembly.
This patent application is currently assigned to X-spine Systems, Inc.. The applicant listed for this patent is X-spine Systems, Inc.. Invention is credited to David Louis Kirschman.
Application Number | 20190328541 16/450495 |
Document ID | / |
Family ID | 50071747 |
Filed Date | 2019-10-31 |
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United States Patent
Application |
20190328541 |
Kind Code |
A1 |
Kirschman; David Louis |
October 31, 2019 |
SPINAL IMPLANT AND ASSEMBLY
Abstract
An implant assembly is shown and described. The implant has at
least one or a plurality of elastic, resilient or flexible arms
that each have a detent adapted to retain at least one screw in a
locked position in the implant. At least one of the arms has a
portion that extends into a screw aperture such that an arm axis is
generally parallel to the axis of the screw after the screw is
received in the implant. In another embodiment, means or a system
for locking the multi-component implant members together is
shown.
Inventors: |
Kirschman; David Louis;
(Dayton, OH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
X-spine Systems, Inc. |
Miamisburg |
OH |
US |
|
|
Assignee: |
X-spine Systems, Inc.
Miamisburg
OH
|
Family ID: |
50071747 |
Appl. No.: |
16/450495 |
Filed: |
June 24, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13804972 |
Mar 14, 2013 |
10327910 |
|
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16450495 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61F 2002/30787
20130101; A61F 2002/30593 20130101; A61F 2002/30604 20130101; A61F
2002/30131 20130101; A61F 2002/30492 20130101; A61F 2002/30383
20130101; A61F 2/447 20130101; A61F 2002/30004 20130101; A61F
2/4455 20130101; A61F 2002/30014 20130101; A61F 2002/30904
20130101 |
International
Class: |
A61F 2/44 20060101
A61F002/44 |
Claims
1. An implant comprising: an implant member adapted to be received
in an implant receiving area between a first bone and a second
bone, wherein said implant member is an integral one-piece
construction, said implant member comprising a first wall
comprising at least one or a plurality of apertures wherein each of
the at least one or the plurality of apertures are adapted to
receive one screw having a screw body comprising a screw head and a
threaded portion, wherein a top surface of the screw head extends
transverse to a longitudinal axis of said threaded portion of the
screw, said implant member having a first bone-engaging surface and
a second bone-engaging surface opposite to the first bone-engaging
surface having an imaginary plane lying midway between said first
bone-engaging surface and said second bone-engaging surface; said
first wall of said implant member comprising at least one or the
plurality of arms extending from said first wall, and wherein each
of said at least one or a plurality of arms comprises a detent
comprising an inner surface, wherein the inner surface associated
with said top surface of said screw head after said screw is
received in each aperture of said at least one or the plurality of
apertures, said detent being adapted to retain said screw in each
aperture of said at least one or the plurality of apertures,
wherein each arm of said at least one or the plurality of arms
comprises a generally elongated portion, the generally elongated
portion defining an arm axis, each arm of said at least one or the
plurality of arms being flexible, resilient or elastic, and wherein
each aperture of said at least one or the plurality of apertures
comprises an aperture axis parallel to a longitudinal axis of said
screw received in the each aperture of said at least one or the
plurality apertures, said arm axis of each arm of said at least one
or the plurality of arms being generally parallel to said
longitudinal axis of a screw received in the aperture.
2. The implant as recited in claim 1, wherein said generally
elongated portion of each arm of said at least one or the plurality
of arms extends in each aperture of said at least one or said
plurality of apertures.
3. The implant as recited in claim 1, wherein said first wall
having a first side wall surface and a generally opposing a second
side wall surface, said first side wall surface being posterior to
said second side wall surface after said implant is implanted, each
of said at least one or the plurality of apertures extending
through said first and second side wall surfaces of said first wall
and each of said at least one or the plurality of arms having a
first end proximate to said first side wall surface and being
coupled to or integral with said implant member, an arm of said at
least one or the plurality of arms being located in each of said at
least one or the plurality of apertures and extending in each of
said at least one or the plurality of apertures toward said second
side wall surface.
4. The implant as recited in claim 1, wherein said arm axis
intersects said imaginary plane at a predetermined angle.
5. The implant as recited in claim 1, wherein each of said at least
one or the plurality of arms defines a resilient finger having an
end integrally formed in or coupled to said implant member, said
resilient finger being urged away from each aperture of said at
least one or the plurality of apertures in response to axial
movement of said screw into each aperture of said at least one or
the plurality of apertures.
6. The implant as recited in claim 5, wherein at least a portion of
said resilient finger becomes operatively associated with said
screw head after said screw is received in each aperture of said at
least one or said plurality of apertures, thereby facilitating
preventing said screw from withdrawing from said implant.
7. The implant as recited in claim 5, wherein said resilient finger
is normally biased such that said detent is in a screw-locking
position.
8. The implant as recited in claim 1, wherein said implant member
comprises said at least one or the plurality of apertures, wherein
each arm of said at least one or the plurality of arms is
associated with each aperture of said at least one or the plurality
of apertures, wherein said at least one or the plurality of arms
having a detent adapted to retain said screw in said implant member
after said screw has been received in at least one of said at least
one or the plurality of apertures.
9. The implant as recited in claim 1, wherein said at least one or
a plurality of arms comprises two arms that diverge away from each
other as they project from an attachment area to said implant
member where said two arms are attached to said implant member by
either a coupling or are integrally with said implant member.
10. The implant as recited in claim 9, wherein said first side wall
surface is generally opposing second side wall surface, said first
side wall surface being posterior to said second side wall surface
after said implant member is implanted, each aperture of said at
least one or the plurality of apertures extending through said
first and second side wall surfaces of said first wall and said
coupling area being associated with said first side wall
surface.
11. The implant as recited in claim 8, wherein said first side wall
surface is generally opposing second side wall surface, said first
side wall surface being posterior to said second side wall surface
after said implant is implanted, each aperture of said at least one
or the plurality of apertures extending through said first and
second side wall surfaces of said first wall, each arm of said at
least one or the plurality of arms having a first end proximate to
said first side wall surface, wherein the generally elongated
portion extends in each aperture of said at least one or the
plurality of apertures toward said second side wall surface.
12. The implant as recited in claim 1, wherein each aperture of
said at least one or the plurality of apertures traversing through
said first and second side wall surfaces, and wherein each arm of
said at least one or the plurality of arms being configured to
extend substantially between said first and second side wall
surfaces at a predetermined angle.
13. The implant as recited in claim 8, wherein said first side wall
surface is generally opposing second side wall surface, said first
and second side wall surfaces, each arm of said at least one or the
plurality of arms being configured to extend substantially between
said first and second side wall surfaces.
14. The implant as recited in claim 1, wherein each aperture of
said at least one or the plurality of apertures comprises a first
end for receiving a screw and a second end associated with said
first or second bone engaging surfaces, said at least one or the
plurality of arms having a free end associated with said first end,
a fixed end associated with said second end, and said generally
elongated portion joining said free end and said fixed end, at
least a portion of said generally elongated portion lying in said
at least one or the plurality of apertures between said first end
and said second end.
15. The implant as recited in claim 8, wherein each aperture of
said at least one or the plurality of apertures comprises a first
end for inserting said screw and a second end associated with said
first or second bone engaging surface, said at least one or the
plurality of arms having a free end associated with said first end,
a fixed end associated with said second end, and said generally
elongated portion joining said free end and said fixed end, at
least a portion of said generally elongated portion lying in said
each aperture of said at least one or said plurality of apertures
between said first end and said second end.
16. The implant as recited in claim 15, wherein each of said
generally elongated portions is located in said each aperture of
said at least one or said plurality of apertures.
17. The implant as recited in claim 1, wherein said detent prevents
said screw from withdrawing from said at least one or the plurality
of apertures after said implant is implanted.
18. The implant as recited in claim 1, wherein said detent is
generally U-shaped.
19. The implant as recited in claim 1, wherein said detent is
generally U-shaped and part of an end of each of said at least one
or the plurality of arms.
20. The implant as recited in claim 1, wherein said each arm of
said at least one or the plurality of arms and said detent are
integral and defined by a cut-out in said implant member.
21. The implant as recited in claim 8, wherein each of said at
least one or the plurality of arms is defined by a cut-out in said
implant member.
22. The implant as recited in claim 8, wherein said implant
comprises a plurality of walls, each of said plurality of walls
define said at least one or the plurality of apertures, with each
said at least one or the plurality of arms being located in each
aperture of said at least one or the plurality of apertures, each
wall of said plurality of walls defining a first end opening where
said screw is introduced into each aperture of said at least one or
the plurality of apertures and a second end opening wherein said
screw exits each aperture of said at least one or the plurality of
apertures, each arm of said at least one or the plurality of arms
extending between a second end of each aperture of said at least
one or the plurality of apertures and a first end of each aperture
of said at least one or the plurality of apertures, said detent
being biased in operative relationship to said screw head in order
to retain said screw head in said implant member after said screw
has been inserted into each aperture of said at least one or the
plurality of apertures and screwed into bone.
23. The implant as recited in claim 8, wherein said detent flexed
to an open position in response to axial movement of at least one
screw being inserted therein.
24. An implant comprising: an implant member adapted to be received
in an implant receiving area between a first bone and a second
bone, wherein said implant member is an integral one-piece
construction, said implant member comprising a first wall
comprising two apertures wherein each of the two apertures are
adapted to receive one screw having a screw body comprising a screw
head and a threaded portion, wherein a top surface of the screw
head extends transverse to a longitudinal axis of said threaded
portion of the screw, said implant member having a first
bone-engaging surface and a second bone-engaging surface opposite
to the first bone-engaging surface having an imaginary plane lying
midway between said first bone-engaging surface and said second
bone-engaging surface; said first wall of said implant member
comprising two arms extending from said first wall, and wherein
each of said two arms comprises a detent comprising an inner
surface, wherein the inner surface associated with said top surface
of said screw head after said screw is received in each aperture of
said two apertures, said detent being adapted to retain said screw
in each aperture of said two apertures, wherein each arm of said
two arms comprises a generally elongated portion, the generally
elongated portion defining an arm axis, each arm of said two arms
being flexible, resilient or elastic, wherein said two arms diverge
away from each other as they project from an attachment area to
said implant member where said two arms are attached to said
implant member by either a coupling or are integrally with said
implant member, and wherein said attachment area of each arm of
said two arms being situated between each aperture of said two
apertures, and wherein each aperture of said two apertures
comprises an aperture axis parallel to a longitudinal axis of said
screw received in each aperture of said two apertures, said arm
axis of each arm of said two arms being generally parallel to said
longitudinal axis of said screw received in each aperture of said
two apertures.
25. An implant comprising: an implant member adapted to be received
in an implant receiving area between a first bone and a second
bone, wherein said implant member is an integral one-piece
construction, said implant member comprising a first wall
containing at least one or a plurality of apertures wherein each of
the at least one or a plurality of apertures are adapted to receive
one screw having a screw body comprising a screw head and a
threaded portion, wherein a top surface of the screw head extends
transverse to a longitudinal axis of said threaded portion of the
screw, said implant member having a first bone-engaging surface and
a second bone-engaging surface opposite to the first bone-engaging
surface having an imaginary plane lying midway between said first
bone-engaging surface and said second bone-engaging surface, and
wherein a material of the implant member comprises a polyether
ether ketone or a titanium; said first wall of said implant member
comprising at least one or the plurality of arms extending from
said first wall , and wherein each of said at least one or a
plurality of arms comprises a detent comprising an inner surface,
wherein the inner surface associated with said top surface of said
screw head after said screw is received in each aperture of said at
least one or the plurality of apertures, said detent being adapted
to retain said screw in each aperture of said at least one or the
plurality of apertures, wherein each arm of said at least one or
the plurality of arms comprises a generally elongated portion, the
generally elongated portion defining an arm axis, each arm of said
at least one or the plurality of arms being flexible, resilient or
elastic, and wherein each aperture of said at least one or the
plurality of apertures comprises an aperture axis parallel to a
longitudinal axis of said screw received in the each aperture of
said at least one or the plurality apertures, said arm axis of each
arm of said at least one or the plurality of arms being generally
parallel to said longitudinal axis of a screw received in the
aperture.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation application of U.S.
patent application No. Ser. 13/804,972, filed on Mar. 14, 2013,
which issued as U.S. Pat. No. 10,327,910 on Jun. 25, 2019, which is
incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0002] This invention relates to spinal implants, and more
specifically, the invention relates to an implant having at least
one resilient, elastic or flexible arm adapted to have an arm axis
that becomes generally parallel to an axis of a screw that is
received in the implant.
2. Description of the Related Art
[0003] Many types of prosthetic devices have been proposed in the
past. For example, U.S. Pat. 5,192,327 to Brantagan concerns a
surgical prosthetic modular implant used singularly or stacked
together to support and fuse together adjacent vertebrae or to
totally or partially replace one or more vertebrae in a vertebral
column. Other surgical implant devices and methods are shown in
U.S. Pat. Nos. 5,192,327; 5,261,911; 5,713,899; 5,776,196;
6,136,002; 6,159,245; 6,224,602; 6,258,089; 6,261,586; 6,264,655;
6,306,136; 6,328,738; 6,592,586; 7,182,782 and 7,641,701. Some or
all of these devices have improved the success rate and have
simplified the surgical techniques in inter-body veritable
fusion.
[0004] Among some of the problems associated with the prior art
devices is that after the device is inserted into a patient during
a surgical procedure, there was a possibility of retropulsion of
the inter-body device and graft material into the spinal cord or
other neurological element.
[0005] Another problem with the prior art devices is that grafting
material, which was inserted into the devices during the surgical
procedure, could not easily be inserted from an anterior
direction.
[0006] Another problem with some prior art systems is that the
screws or fasteners which secured implant to bone sometimes had a
tendency to unscrew themselves because the implant itself may move
or withdraw.
[0007] In some prior art implants, screws are placed at an angle
relative to the plane in which the cage lies so that the screws can
be screwed directly into an upper vertebra and/or a lower vertebra.
While solutions for retaining screws in the implant plates have
included, for example, the use of a resilient arm and approaches
used in U.S. Pat. No. 7,641,701, these approaches do not work as
effectively with implants that use angled screws. Such approaches
are also not practical for use with implants that do not have
available space for using an arm.
[0008] What is needed, therefore, is a screw retaining system that
is particularly adapted for use with implants having angled screws.
What is also needed is a system and means for locking a
multi-component implant assembly together.
SUMMARY OF THE INVENTION
[0009] It is, therefore, an object of one embodiment to provide
means and a system for locking screws in an implant when there is
limited space on the implant for providing an integral lock, for
example, or when a face of the implant is narrow.
[0010] Another object of one embodiment is to provide a system and
means for locking a multi-component implant assembly together.
[0011] Still another object of another embodiment is to provide an
implant having at least one or a plurality of arms that are used to
retain a screw in a locked position in the implant and that
facilitate preventing the screws from withdrawing from the implant
and from bone.
[0012] Still another object of another embodiment is to provide an
implant having at least one or a plurality of resilient, elastic or
flexible arms having detents, wherein the at least one or a
plurality of arms is/are situated in one or more screw apertures of
the implant.
[0013] Yet another object of one embodiment is to provide an
implant having a plurality of flexible, resilient or elastic arms,
each having a locking detent, that are adapted to be arranged in a
plurality of apertures that are adapted to receive at least one of
the arms that has at least one screw and wherein at least one
elongated portion is generally parallel to an axis of the screw
after the screw is inserted in the implant and screwed into
bone.
[0014] In one aspect, one embodiment of the invention comprises an
implant comprising an implant member adapted to be received in an
implant receiving area between a first bone and a second bone
comprising at least one aperture adapted to receive a screw having
a screw head, the implant member comprising at least one arm having
a detent that becomes associated with the screw head after the
screw is received in the at least one aperture, the detent being
adapted to retain the screw in the at least one aperture and the at
least one arm being flexible, resilient or elastic and having a
generally elongated portion having an arm axis that is not parallel
relative to an imaginary implant plane lying generally midway
between a first bone-engaging surface adapted to engage or become
associated with the first bone and a second bone-engaging surface,
the generally elongated portion extending in the at least one
aperture.
[0015] In another aspect, another embodiment of the invention
comprises an implant assembly comprising an implant member having
an imaginary implant plane, the implant member comprising a
plurality of apertures each adapted to receive a screw having a
screw head, and a second implant member adapted to be received
between bones and having an open end configured to mate with the
implant member, the implant member comprising a plurality of arms
associated with the plurality of apertures, respectively, in the
implant member, the plurality of arms being adapted to retain a
plurality of screws in the plurality of apertures, respectively,
after the plurality of screws have been received in the plurality
of apertures, each of the plurality of arms further comprising a
generally elongated arm having an elongated arm axis that is not
parallel to the imaginary implant plane, the plurality of arms
being flexible, resilient or elastic and having a generally
elongated portion having an arm axis that is not parallel relative
to the imaginary implant plane lying generally midway between a
first bone-engaging surface adapted to engage or become associated
with a first bone and a second bone-engaging surface, the generally
elongated portion extending in the plurality of apertures.
[0016] In another aspect, another embodiment of the invention
comprises an implant that comprises an implant body having at least
one aperture adapted to receive a screw having a locking wall, at
least one resilient, elastic or flexible arm adapted to capture at
least a portion of the locking wall, thereby locking or retaining
said screw in the implant.
[0017] Still another object is to provide a resilient, elastic or
flexible arm having a U-shaped detent adapted to receive a wall of
a screw head.
[0018] Another object is to provide a screw locking approach that
is adapted to enable a resilient arm to be used on an implant where
space on an exterior surface or wall of the implant is
constrained.
[0019] These and other objects and advantages of the invention will
be apparent from the following description, the accompanying
drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a perspective view of an implant in accordance
with one embodiment of the invention;
[0021] FIG. 2 is another perspective view of the implant shown in
FIG. 1;
[0022] FIG. 3 is an exploded view of the implant shown in FIG.
1;
[0023] FIG. 4 is a front view of the implant shown in FIG. 1
situated between adjacent vertebrae;
[0024] FIG. 5 is another view illustrating a screw causing at least
one arm to move to an open position in response to the axial
movement of the screw in the implant;
[0025] FIG. 6 is a fragmentary view illustrating an arm moving from
an open position shown in FIG. 5 to a closed position after a
detent "clears" a screw shoulder;
[0026] FIG. 6A is a fragmentary view showing features of the detent
capturing at the screw wall;
[0027] FIG. 7 is an enlarged fragmentary view showing various
features of one arm associated with a first aperture;
[0028] FIG. 8 is a sectional view taken along the line 8-8 in FIG.
7;
[0029] FIG. 9 is a sectional view taken along the line 9-9 in FIG.
7;
[0030] FIG. 10 is a sectional view taken along the line 10-10 in
FIG. 7;
[0031] FIG. 11 is a perspective view of another embodiment showing
an integral one-piece construction; and
[0032] FIG. 12 is a perspective view of an implant that is an
integral one-piece construction.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0033] Referring now to FIGS. 1-12, an implant and an implant
assembly 10 are shown. The implant assembly 10 comprises a first
implant member 12 and a second implant member 14. The implant
assembly 10 is adapted to be received in an implant assembly
receiving area 15 (FIG. 4) between bones, such as between a first
vertebra or bone 17 and a second vertebra or bone 19. The second
implant member 14 has an open-end configuration as illustrated in
FIG. 3. Further details of the second implant member 14 will be
described later herein. Although not shown, it should be understood
that the first implant member 12 could have an open-end
configuration with U-shaped channel (not shown) and the second
implant member 14 could have a mating U-shaped projection (not
shown) for receipt in the U-shaped channel.
[0034] The first implant member 12 comprises a first wall 16 having
a generally U-shaped projection 18. As best illustrated in FIG. 3,
note that the second implant member 14 comprises a generally
U-shaped wall 20 having a first wall portion 20a, a second wall
portion 20b and a third wall portion 20c joining the first and
second wall portions 20a, 20b to define a generally U-shaped
channel 22. In the illustration being described, the generally
U-shaped channel 22 is adapted to provide a guide channel for
receiving and guiding the generally U-shaped projection 18, as best
illustrated in FIGS. 1 and 3, into a mating or assembled
configuration. The generally U-shaped projection 18 is adapted and
configured so that it complements the shape of the generally
U-shaped channel 22 and fits snugly therein.
[0035] As best illustrated in FIG. 3, note that the first wall
portion 20a comprises through-holes or bores 28 and 30 defined by
generally cylindrical walls 26a and 26b, respectively. Likewise,
the second wall portion 20b comprises through-holes or bores 34 and
36 that are defined by generally cylindrical walls 32a and 32b,
respectively. Note that the through-holes and bores 34 and 36 are
generally aligned with the through-holes or bores 28 and 30,
respectively, as shown.
[0036] The generally U-shaped projection 18 likewise comprises a
pair of generally cylindrical walls 38a and 38b that define
through-holes or bores 40 and 42, respectively. It should be
understood that after the first implant member 12 is mounted in the
second implant member 14, the through-holes or bores 30, 42 and 36
become generally aligned to provide a first lock aperture and
through-holes or bores 28, 40 and 34 being generally aligned to
provide a second lock aperture. The first and second lock apertures
are adapted to receive pins 44 and 46, respectively, in order to
lock the first and second implant members 12 and 14 together. Thus,
the implant assembly 10 provides means and apparatus for locking
the first and second implant members 12 and 14 together as shown in
FIGS. 8-10.
[0037] Referring now to FIGS. 3 and 7-10, details of a screw
locking system 49 (FIG. 1) will now be described. The screw locking
system 49 is adapted to retain at least one or a plurality of
screws, such as screws 50 and 52 (FIG. 1), in the implant assembly
10 and prevent them from withdrawing therefrom after the implant
assembly 10 is assembled together and implanted in the implant
assembly receiving area 15 and the at least one or a plurality of
screws 50 and 52 are screwed into the first and second vertebrae or
bones 17 and 19, respectively.
[0038] The first implant member 12 comprises a first wall 12a,
which is anterior or downward of a rear wall 14a of the second
implant member 14 after the implant assembly 10 is assembled and
implanted. It should be understood that when the implant assembly
10 is inserted into the implant assembly receiving area 15 between
the first vertebra or bone 17 and the second vertebra or bone 19
(FIG. 4), the first wall 12a becomes associated with an anterior
opening or area 21 into the implant receiving area 15. A second
wall or rear wall 14b of the second implant member 14 becomes
associated with a posterior area (not shown) of the implant
assembly receiving area 15. In general, the first wall 12a is
adapted and configured to receive the at least one or a plurality
of screws 50 and 52 and the screw locking system 49 secures them in
a locked position so that after the at least one or a plurality of
screws 50 and 52 are screwed into bone, they will become locked in
the implant assembly 10 and not withdraw therefrom. The screw
locking system 49, in turn, facilitates preventing the screws 50
and 52 from unscrewing from the bones into which they are
screwed.
[0039] The first wall 12a comprises at least one or a plurality of
apertures or bores, such as bore or aperture 60 (FIG. 3) having a
first aperture or bore axis A1 and a second aperture 62 having a
second aperture or bore axis A2, respectively. The cylindrical
bores or apertures 60 and 62 are defined by generally cylindrical
walls 64 and 66, respectively. Note that the bores or apertures 60
and 62 and their respective bore axes A1 and A2, respectively, are
angled in different directions (i.e., one upward and one downward
in the illustration shown in FIG. 3) so that the screws 50 and 52
may engage and be screwed into different bones, such as the first
vertebra or bone 17 and the second vertebra or bone 19.
[0040] In the illustration being described, the first wall 12a
comprises a first side wall surface 12a1 and a second side wall
surface 12a2 that is generally opposed to the first side wall
surface 12a1. Note that the first side wall surface 12a1 is
posterior relative to the second side wall surface 12a2 when viewed
from a front of the implant assembly 10 after the implant assembly
10 is implanted into the implant receiving area 15.
[0041] In one embodiment, each of the plurality of bores or
apertures 60 and 62 comprises at least one or a plurality of arms,
fingers or latches. For example, the first bore or aperture 60 and
the second bore or aperture 62 comprise a first arm 70 and a second
arm 72, respectively. For ease of illustration, the at least one or
a plurality of arms will be illustrated here as comprising the
first arm 70 and the second arm 72 associated with the first bore
or aperture 60 and the second bore or aperture 62, respectively,
but it should be understood that more or fewer apertures could be
provided and more or fewer arms could be used or provided in the
apertures 60 and 62. The first and second arms 70 and 72 are
operatively associated with and located in the first and second
bores or apertures 60 and 62, respectively. In the illustration,
each of the first and second arms 70 and 72 are flexible, elastic
and/or resilient so that they can be actuated from a normally
closed position (illustrated in FIGS. 1-4) to an actuated open
position (illustrated in FIG. 5 relative to the first arm 70).
[0042] Each of the first and second arms 70 and 72 comprises
elongated portions 70a and 72a, free ends or detent ends 70b and
72b and fixed ends or coupling ends 70c and 72c. The first and
second arms 70 and 72 have an associated arm axis AA1 (FIGS. 3, 9
and 10) and AA2, respectively, in the illustration being described.
In this example, the arm axis, such as arm axis AA1, is not
parallel or generally not parallel with respect to an imaginary
plane IP (FIG. 10) in which the implant assembly 10 lies and is
also generally not parallel to a coronal plane CP (illustrated in
FIG. 9). For ease of understanding, the imaginary plane IP (FIG.
10) lies generally midway between a first bone-engaging surface 37
and a generally opposed second bone-engaging surface 39, which is
adapted and configured to engage or become associated with the
first and second vertebrae or bones 17 and 19, respectively, after
the implant assembly 10 is received in the implant receiving area
15. The first and second arms 70 and 72 are not generally parallel
to the imaginary plane IP or coronal plane CP as mentioned, and it
is important to note that they lie at different angles with respect
to each other and with respect to the imaginary plane IP and
coronal plane CP, as illustrated by the angles .THETA. and X (FIG.
9) and angles .PHI. and Y (FIG. 10).
[0043] In the illustration being described, the first implant
member 12 is machined to define the apertures 60 and 62 and their
associated first and second arms 70 and 72, respectively. In the
illustration being described, the first and second arms 70 and 72
are defined by at least one or a plurality of cut-out areas 84, 85,
86, 87 and 88 (with only areas 84 and 86 labeled in FIG. 7 with
respect to first arm 70 for ease of illustration) in a coupling or
intermediate portion 90 of the first wall 12a. In the illustration
being described, the second arm 72 comprises the elongated portion
72a that joins the free end or detent end 72b and the coupling or
fixed end 72c which couples or joins the second arm 72 to the
coupling or intermediate portion 90. For example, the first implant
member 12 was machined and cut-out areas 84, 85, 86, 87 and 88 were
machined or cut out to define the second aperture 62 and its
associated second arm 72, as best illustrated in FIG. 7.
[0044] The first arm 70 extends from a first side wall surface 12a1
toward the generally opposing second side wall surface 12a2 as best
illustrated in FIGS. 7-10. Likewise, the second arm 72 is
configured similarly except that it extends upward and toward the
reader (as viewed in FIG. 7) from the first side wall surface 12a1
toward an opening 62a of the aperture 62 as illustrated.
[0045] Notice that the second arm 72 has the coupling or fixed end
72c that is coupled to or integrally formed in the coupling or
intermediate portion 90 and angles upward in the aperture 62 (as
viewed in FIGS. 5, 7 and 8) toward the second side wall surface
12a2. In contrast, note that the first arm 70 has its fixed end 70c
coupled to or integral with the coupling or intermediate portion 90
and extends or projects in the aperture 60 and angles downward (as
viewed in FIGS. 5, 7 and 8) from the first side wall surface 12a1
toward the second side wall surface 12a2. Thus, it should be
appreciated that in this embodiment, the first and second arms 70
and 72 diverge as they extend or project away from the coupling or
intermediate portion 90 associated with the first side wall surface
12a1.
[0046] Advantageously, each of the first and second arms 70 and 72,
therefore, extend from the posterior first side wall surface 12a1
toward the anterior second side wall surface 12a2. Thus, as the
first and second arms 70 and 72 extend or project from the coupling
or intermediate portion 90, they not only generally diverge from
each other, but they also generally diverge, project or extend away
from both the imaginary plane IP and the coronal plane CP, as
illustrated in FIGS. 9 and 10. It is important to note, however,
that their axes, namely axes AA1 and AA2, are generally parallel to
their respective bore or aperture axes A1 and A2, respectively.
This is best shown in FIG. 3.
[0047] As illustrated in the Figures, after the implant assembly 10
is implanted, for example, between the first and second vertebrae
or bones 17 and 19 (FIG. 4) in the implant receiving area 15, the
first side wall surface 12a1 becomes situated posterior relative to
the second side wall surface 12a2. Each of the first and second
arms 70 and 72 are located in the apertures 60 and 62 and extend or
project in the apertures 60 and 62 toward the second side wall
surface 12a2 as mentioned, and their respective free ends or detent
ends 70b, 72b become operatively positioned and associated with
openings 60a and 62a into the apertures 60 and 62,
respectively.
[0048] Thus, it should be appreciated that the fixed ends 70c and
72c of the first and second arms 70 and 72 are integral with or
coupled to the coupling or intermediate portion 90 and extend
interiorly in the at least one or a plurality of apertures 60 and
62, respectively, as shown. In the illustration being described,
this configuration causes the free end or detent end 70b, 72b of
the first and second arms 70 and 72, respectively, to be
operatively positioned relative to the entry opening, such as
openings 60a and 62a, into the at least one or plurality of
apertures 60 and 62. It should be understood that this design is
advantageous because it maximizes use of available space by placing
the first and second arms 70 and 72 inside the apertures 60 and 62,
respectively, as opposed to outside the aperture (such as on the
second side wall surface 12a2).
[0049] As best illustrated in FIGS. 4-6, after the implant assembly
10 is implanted in the implant receiving area 15, a screw, such as
screw 50 or screw 52, can be inserted or received in the apertures
60, 62, respectively, and ultimately screwed into the bones 17 and
19, respectively. Note that the free ends or detent ends 70b and
72b are engaged by the screw heads 50a and 52a, respectively, and
are actuated or driven away from their respective axes A1 and A2.
For example, when screw head 50a engages the free end or detent end
70b, it is driven or moves in the direction of arrow A in FIG. 5 in
response to the axial movement of the screw 50 as it is screwed
into the first vertebra or bone 17 (FIGS. 4 and 5).
[0050] Each free end or detent end 70b and 72b comprises a
generally U-shaped detent 70b1 (FIGS. 4, 6A and 11) and 72b1,
respectively. Although the generally U-shaped detent 70b1 and 72b1
are shown situated at the free ends or detent ends 70b and 72b, it
should be understood that they could be positioned at other
positions or locations on the first and second arms 70 and 72,
respectively. The detents 70b1 and 72b1 define receiving areas or
locking channels 70b1i and 72b1i, respectively, and each comprise
or define a pawl or latch 70d, 72d as best illustrated in FIG. 7.
As the screws 50 and 52 are driven axially into the apertures 60
and 62, respectively, when the screws 50 and 52 are screwed into
the first vertebra or bone 17 (FIG. 4) and the second vertebra or
bone 19, the first and second arms 70 and 72 move or deflect until
latches 70d and 72d clear top edges 50a1i and 52a1i of the
generally circular wall portions 50a1 and 52a1 (FIG. 1) of the
screws 50 and 52, respectively, whereupon the resilient first and
second arms 70 and 72 cause the detents 70b1 and 72b1 move back
toward their home position toward the axes A1 and A2 of the
apertures 60 and 62, respectively. For example, the detent 70b1
moves in the direction of arrow B in FIG. 6 toward the axis A1.
This causes the latches 70d and 72d to become operatively
positioned so that the receiving areas or locking channels 70b1i
and 72b respectively, become generally aligned with, and adapted to
receive, the generally circular wall portions 50a1 and 52a1,
respectively, as shown in FIGS. 1 and 2.
[0051] After the detents 70b1 and 72b1 "clear" the wall portions
50a1 and 52a1, the screws 50 and 52 may be backed out or unscrewed
slightly until the top surfaces 50a1i and 52a1i engage the surface
70d1 (FIG. 4) and 72d1, respectively, thereby causing the wall
portions 50a1 and 52a1 to be captured in the channels 70b1i and
72b1i, respectively. Note that the wall portions 50a1 and 52a1
comprise a thickness that is slightly smaller than a width W (FIG.
6A) of the channels 70b1i and 72b1i. The screws 50 and 52 become
locked or retained in the implant assembly 10 so that they cannot
withdraw therefrom or from the first and second vertebrae or bones
17 and 19, thereby locking the screws 50 and 52 in the implant
assembly 10. If it is desired to remove the screws 50 and 52, the
first and second arms 70 and 72 can be manually deflected to the
open position (e.g., first arm 70 can be actuated in the direction
of arrow A in FIG. 5) and the screws 50 and 52 unscrewed from the
first and second vertebrae or bones 17 and 19, respectively.
[0052] Although not shown, a generally L-shaped detent may be used
with the free ends if, for example, the screws 50 and 52 did not
have the wall portions 50a1 and 52a1.
[0053] Advantageously, the generally U-shaped capturing detents
70b1 and 72b1 are adapted to prevent the screws 50 and 52 from
withdrawing from the implant assembly 10. This design also
facilitates preventing the first and second arms 70 and 72 from
splaying or moving away from their respective axes AA1 and AA2,
respectively. Notice in FIG. 4 that overhang wall portions 70b3 and
72b3 of detents 70b1 and 72b1, respectively, are generally arcuate
or curved and generally complement or match a shape of an inner
curved surface 50c and 52c of the screws 50 and 52, as shown in
FIGS. 1, 2 and 4-6.
[0054] In the illustration being described, the detent 70b1 is
defined by and located on the free end or detent end 70b and detent
72b1 is defined by and located on the free end or detent end 72b.
As described, the detents 70b1 and 72b1 are generally U-shaped as
shown in FIG. 6A, but it should be understood that they could
assume other shapes or configurations. As mentioned earlier, each
of the first and second arms 70, 72 are defined by machining the
first wall 12a of the first implant member 12 as mentioned. The
free ends or detent ends 70b, 72b and their respective detents 70b1
and 72b1 are also defined by machining. The detents 70b1 and 72b1
comprise beveled surfaces 70b2 (FIGS. 1, 2 and 4) and 72b2,
respectively, that are generally coplanar with the second side wall
surface 12a2.
[0055] The free ends or detent ends 70b and 72b also comprise
generally curved or arcuate camming surfaces 70b3 and 72b3 (FIGS.
1, 2 and 7) which engage the screw heads 50a and 52a, respectively,
when the screws 50 and 52 are driven axially into the apertures 60
and 62 as described earlier. The screws 50 and 52 cam against the
surfaces 70b3 and 72b4, respectively, which causes the free ends or
detent ends 70b and 72b to deflect away from the axes A1 and A2,
respectively. Again, it should be noted that the resilient first
and second arms 70, 72 are urged away from their respective bores
or apertures 60 and 62 and away from the axes A1 and A2 in response
to the axial movement of the screws 50 and 52 in the bores or
apertures 60 and 62.
[0056] It should be understood that the elongated portion, such as
the elongated portion 70a of first arm 70 and elongated portion 72a
of second arm 72, are in communication with at least one of the
plurality of apertures 60, 62, respectively, and notice that they
facilitate defining at least a portion of the boundary of the bores
or apertures 60, 62, respectively. For example, note relative to
the first arm 70 in FIG. 7, the surface 71 facilitates defining a
portion or boundary of the bore or aperture 60.
[0057] As shown in FIG. 7, walls 64 and 66 comprise seats 64a and
66a, respectively. The seats 64a and 66a are adapted to receive and
support the heads 50a and 52a of the screws 50 and 52,
respectively, after the screws 50 and 52 are screwed into bone.
[0058] Although the embodiment being described shows a pair of
apertures, namely apertures 60 and 62, it should be appreciated
that more or fewer apertures could be used. Also, it should be
understood that the locking system 49 of the embodiments shown and
described could be used with other types of implants, such as
plates, cages, spinal implants, bone implants, fusion devices and
the like.
[0059] Referring back to FIG. 7, note that the coupling or
intermediate portion 90 is an integral construction in the first
wall 12a and it integrally joins and couples the fixed ends or
coupling ends 70c and 72c as shown. The coupling or intermediate
portion 90 is situated between the first and second arms 70 and 72
and facilitates and enables the first and second arms 70 and 72 to
extend from the first side wall surface 12a1 toward the second side
wall surface 12a2 so that the first and second arms 70 and 72 can
extend or project into the apertures 60 and 62, respectively. This
configuration also enables the free ends or detent ends 70b and 72b
to become operatively associated with openings 60a and 62a,
respectively, into the apertures 60 and 62 as mentioned earlier.
Advantageously, the coupling or intermediate portion 90 is
generally situated or located between the pair of apertures 60 and
62 as shown.
[0060] As illustrated in FIGS. 9 and 10, the first and second side
wall surfaces 12a1 and 12a2 are generally perpendicular to the
imaginary plane IP and generally parallel to the coronal plane CP.
As mentioned earlier herein, the axes AA1 and AA2 of the first and
second arms 70 and 72 diverge (as illustrated in FIGS. 7, 9 and
10), and they are generally not parallel to either the imaginary
plane IP or the coronal plane CP. Indeed and as mentioned earlier
herein, the axes AA1 and AA2 of the first and second arms 70 and 72
form acute angles .THETA., .PHI. and X, Y, respectively, of
generally less than about 45 degrees with respect to the imaginary
plane IP and coronal plane CP. In a preferred embodiment the angles
.THETA. and .PHI. are between about 20-70 degrees and angles X and
Y are between about 20-70 degrees. For example, note that the
angles .THETA. and X in FIG. 9, which shows the angles between the
imaginary plane IP and the coronal plane CP and the longitudinal
axis AA1 of the first arm 70, is less than about 45 and 70 degrees,
respectively. Again, and as mentioned earlier herein, this axis AA1
and the imaginary plane IP and the coronal plane CP are generally
not parallel, but axis AA1 and axis A1 of the aperture 60 are
generally parallel. Likewise, and as shown in FIG. 10, the axis AA2
is not generally parallel to the imaginary plane IP and the coronal
plane CP, but it is generally parallel to the axis A2, which is the
axis of the aperture 62.
[0061] The free ends or detent ends 70b and 72b extend between the
first and second side wall surfaces 12a1 and 12a2 as shown. Indeed,
a majority, if not all, of the first and second arms 70 and 72,
including their respective elongated portions 70a and 72a, are in
communication with and lie in and project or extend a substantial
or majority of a length of the apertures 60 and 62. After the
screws 50 and 52 are received in the apertures 60 and 62, note that
their axes become generally co-axial with the axes A1 and A2,
respectively, of apertures 60 and 62. The axes of the screws 50 and
52 also become generally parallel to the axes AA1 and AA2,
respectively, of the first and second arms 70 and 72.
[0062] Advantageously, the configuration of the screw locking
system 49 described herein associates the fixed end or coupling end
70c and 72c with exit areas 60b and 62b, respectively, of the
apertures 60 and 62 and the free ends or detent ends 70b and 72b
with the openings 60a and 62a into the apertures 60 and 62.
[0063] During use, the first and second implant members 12 and 14
are assembled by sliding the projection 18 into the channel 22. The
generally U-shaped projection 18 is guided into the channel 22
until the holes or bores 40 and 42 become generally aligned with
the holes or bores 28, 34 and 30, 36, respectively. Once they
become aligned, the pins 44 and 46, can be inserted as illustrated
in FIGS. 7-10, and the first implant member 12 and second implant
member 14 become locked together to provide the implant assembly
10. The generally U-shaped projection 18 cooperates with the first
wall 12a to define a fusion material receiving area 73 (FIG. 3).
This fusion material receiving area 73 is filled with a fusion or
graft material by the user. The implant assembly 10 is situated
between the first and second vertebrae or bones 17 and 19 in the
implant receiving area 15 as generally illustrated in FIG. 4. In
this assembled position, the surface 18a of the projection 18
becomes generally coplanar with the generally U-shaped third wall
portion 20c as shown in FIG. 7.
[0064] After the implant assembly 10 is positioned in the implant
receiving area 15, the screws 50 and 52 are guided into the
apertures 60, 62, respectively, and screwed into the first and
second vertebrae or bones 17 and 19 until the channels 70b1i and
72b1i become operatively associated with and positioned generally
opposed to the wall portions 50a1 and 52a1, respectively, as
described earlier herein. As mentioned earlier, after the screws 50
and 52 "clear" their respective detents 70b, 72b, the first and
second arms 70, 72 urge the detents 70b, 72b to their home
position, whereupon the channels 70b1i and 72b1i become operatively
associated or positioned in opposed relationship to the wall
portions 50a1 and 52a1, respectively. The user may optionally
unscrew or back out the screws 50 and 52 enough to cause the wall
portions 50a1 and 52a1 to be captured in their respective generally
U-shaped channel 70b1i or 72b1i. The implant assembly 10 becomes
screwed and locked in the implant receiving area 15, thereby
preventing the first implant member 12 separating from the second
implant member 14, facilitating preventing the screws 50 and 52
from unscrewing, and also preventing the implant assembly 10 from
expulsion or withdrawing from the implant receiving area 15 once
the screws 50 and 52 are locked in the apertures 60 and 62 by the
detents 70b1 and 72b1, respectively. If the screws 50 and 52 expel
or unscrew, the wall portions 50a1 and 52a1 will be captured in the
channels 70b1i and 72b1i, respectively.
[0065] Advantageously, the implant assembly 10 comprises the screw
locking system 49 which facilitates preventing at least one or a
plurality of screws, such as screws 50 and 52, from withdrawing
from the implant assembly 10. Although the apertures 60 and 62 and
their associated first and second arms 70 and 72, respectively, are
shown as extending in diverging directions as described earlier, it
should be understood that the apertures 60, 62 and the first and
second arms 70, 72 could be arranged differently. For example, they
could be arranged so that the axes AA1 and AA2 are generally
parallel, extend in the same direction but diverge or converge in a
common horizontal or vertical plane, extend in different directions
and diverge, as illustrated in FIGS. 1-10, but with angles .THETA.,
X (FIG. 9) and .PHI., Y (FIG. 10) that are different, or the like.
An important feature, however, is that the at least one or a
plurality of the apertures have the screw locking system 49 in the
form of at least one or a plurality of arms, such as one or more of
the first and second arms 70, 72, respectively, and the arm axes,
such as the axes AA1 and AA2 of the first and second arms 70 and
72, respectively, are generally parallel with the aperture axes,
such as the axes A1 and A2 of the apertures 60 and 62. Note that a
majority of the first and second arms 70 and 72, including the
elongated portions 70a, 72a, are situated in the apertures 60 and
62, respectively.
[0066] Another feature is that the first and second arms 70, 72 are
situated in the apertures which is advantageous because of space
and size constraints associated with the second side wall surface
12a2. Situating a majority or all of the first and second arms 70,
72 in the apertures 60, 62, respectively, enables the use of the
first and second arms 70 and 72.
[0067] In one embodiment, the first and second implant members 12
and 14 are made of different materials, such as PEEK and titanium,
with the second implant member 14 having a modulus of elasticity
similar to bone.
[0068] FIG. 12 shows another embodiment wherein the implant
assembly 10'' is an integral, one-piece body 17'' construction,
rather than the two-piece construction shown in FIG. 1. In this
embodiment, like parts are identified with the same part numbers,
except that a double prime mark ('' '' '') has been added to the
part numbers. In one embodiment, the implant assembly 10'' is a
monolithic construction machined from titanium. Notice it has the
locking system 49'' the same or similar to the embodiment of FIGS.
1-11.
[0069] While the system, apparatus and method herein described
constitute preferred embodiments of this invention, it is to be
understood that the invention is not limited to this precise
system, apparatus and method, and that changes may be made therein
without departing from the scope of the invention which is defined
in the appended claims.
* * * * *