U.S. patent application number 16/135754 was filed with the patent office on 2019-01-17 for dynamic stabilization system.
The applicant listed for this patent is Zimmer Spine S.A.S.. Invention is credited to Karl P. Belliard, Bruno Ichelmann, Wouter Ten Tusscher.
Application Number | 20190015134 16/135754 |
Document ID | / |
Family ID | 53483752 |
Filed Date | 2019-01-17 |
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United States Patent
Application |
20190015134 |
Kind Code |
A1 |
Belliard; Karl P. ; et
al. |
January 17, 2019 |
DYNAMIC STABILIZATION SYSTEM
Abstract
A spinal stabilization system including an insert positionable
in the channel of the housing of a vertebral anchor, and an
associated support construct including a spacer and at least one
cord extending through the insert. In some instances the construct
includes first and second cords extending through first and second
bores of the insert. A clamping member clamps the cord(s) in the
insert. In some instances the clamping member includes first and
second tabs movable in channels in first and second flanges of the
insert.
Inventors: |
Belliard; Karl P.; (La
Membrolle, FR) ; Ichelmann; Bruno; (Limoges, FR)
; Ten Tusscher; Wouter; (Ludon Medoc, FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Zimmer Spine S.A.S. |
Bordeaux |
|
FR |
|
|
Family ID: |
53483752 |
Appl. No.: |
16/135754 |
Filed: |
September 19, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
15172631 |
Jun 3, 2016 |
10098670 |
|
|
16135754 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 17/7032 20130101;
A61B 17/7002 20130101; A61B 17/7005 20130101; A61B 17/704 20130101;
A61B 17/7037 20130101; A61B 17/7022 20130101; A61B 17/7053
20130101; A61B 17/7008 20130101 |
International
Class: |
A61B 17/70 20060101
A61B017/70 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 4, 2015 |
EP |
15290148.4 |
Claims
1. A spinal stabilization system comprising: an insert positionable
in a channel of a housing of a vertebral anchor, the insert having
a first end positionable on a first side of the housing of the
vertebral anchor and a second end positionable on a second side of
the housing of the vertebral anchor; and a support construct
including a spacer and first and second cords extendable through
the spacer, the first and second cords positionable through the
insert.
2. The spinal stabilization system of claim 1, wherein the insert
includes a first bore for receiving the first cord therethrough and
a second bore for receiving the second cord therethrough.
3. The spinal stabilization system of claim 1, further comprising:
a vertebral anchor including a housing defining a channel; and a
fastener configured to rotatably engage the housing of the
vertebral anchor, wherein rotational engagement of the fastener
with the housing causes the fastener clamp both the first and
second cords in the insert.
4. The spinal stabilization system of claim 3, wherein the fastener
directly contacts each of the first and second cords to exert a
clamping force directly on the first and second cords.
5. The spinal stabilization system of claim 3, wherein the fastener
includes a threaded portion and a protuberance extending from the
threaded portion, wherein the protuberance is extendable into an
opening of the insert to contact each of the first and second
cords.
6. The spinal stabilization system of claim 5, wherein the opening
intersects with each of the first and second bores.
7. The spinal stabilization system of claim 3, wherein rotational
engagement of the fastener with the housing causes the fastener to
clamp both the first and second cords in the insert and secure the
insert in the housing of the vertebral anchor.
8. The spinal stabilization system of claim 7, wherein the first
bore extends parallel to and offset from the second bore, and the
opening extends perpendicular to and between the first and second
bores.
9. The spinal stabilization system of claim 3, wherein the
vertebral anchor includes a threaded shaft extending from the
housing, wherein the threaded shaft has a lumen extending
therethrough for advancement over a K-wire.
10. The spinal stabilization system of claim 9, wherein the opening
extends entirely through the insert such that the insert is
advanceable over the K-wire into the housing of the vertebral
anchor with the K-wire positionable between the first and second
cords.
11. A spinal stabilization system comprising: an insert securable
to a housing of a vertebral anchor, the insert having a first
flange positionable on a first side of the housing of the vertebral
anchor, a second flange positionable on a second side of the
housing of the vertebral anchor, and a medial portion between the
first and second flanges positionable in a channel of the housing
of the vertebral anchor; and a support construct including a spacer
and a cord extendable through the spacer, the cord positionable
through a bore of the insert; a clamping member movable relative to
the medial portion to clamp the cord in the bore of the insert.
12. The spinal stabilization system of claim 11, wherein the
clamping member includes a concave engagement surface configured to
press against a portion of the periphery of the cord, preferably 30
degrees or more of the periphery of the cord.
13. The spinal stabilization system of claim 11, wherein the
clamping member includes a first tab movable in a channel in the
first flange and a second tab movable in a channel in the second
flange.
14. The spinal stabilization system of claim 13, wherein the
clamping member is configured to be held in a loading position
prior to clamping onto the cord.
15. The spinal stabilization system of claim 13, wherein each of
the channels has an upper portion having a first width and a lower
portion having a second width, the first width being less than the
width of the first and second tabs to form an interference fit with
the first and second tabs, and the second width being greater than
the width of the first and second tabs.
16. The spinal stabilization system of claim 13, wherein each of
the channels has an upper portion having a first width and a lower
portion having a second width, wherein the first width and the
second width are equal.
17. The spinal stabilization system of claim 13, wherein each of
the channels has an upper portion having a protuberance extending
radially towards the bore, wherein each of the first tab and the
second tab have a void disposed therein to matingly receive the
respective protuberance.
Description
RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 15/172,631, filed on Jun. 3, 2016, which
claims the benefit of priority to European Patent Application
Serial No. 15290148.4, filed Jun. 4, 2015, the benefit of priority
of each of which is claimed hereby, and each of which are
incorporated by reference herein in its entirety.
TECHNICAL FIELD
[0002] The disclosure is directed to a vertebral stabilization
system. More particularly, the disclosure is directed to a dynamic
stabilization system and components thereof.
BACKGROUND
[0003] The spinal column of a patient includes a plurality of
vertebrae linked to one another by facet joints and an
intervertebral disc located between adjacent vertebrae. The facet
joints and intervertebral disc allow one vertebra to move relative
to an adjacent vertebra, providing the spinal column a range of
motion. Diseased, degenerated, damaged, or otherwise impaired facet
joints and/or intervertebral discs can cause the patient to
experience pain or discomfort and/or loss of motion, thus prompting
surgery to alleviate the pain and/or restore motion of the spinal
column.
[0004] One possible method of treating these conditions is to
immobilize a portion of the spine to allow treatment.
Traditionally, immobilization has been accomplished by rigid
stabilization. For example, in a conventional spinal fusion
procedure, a surgeon restores the alignment of the spine or the
disc space between vertebrae by installing a rigid fixation rod
between pedicle screws secured to adjacent vertebrae. Bone graft is
placed between the vertebrae, and the fixation rod cooperates with
the screws to immobilize the two vertebrae relative to each other
so that the bone graft can fuse with the vertebrae.
[0005] Dynamic stabilization has also been used in spinal treatment
procedures. Dynamic stabilization does not result in complete
immobilization, but instead permits a degree of mobility of the
spine while also providing sufficient support and stabilization to
effect treatment. One example of a dynamic stabilization system is
the Dynesys.RTM. system available from Zimmer Spine, Inc. of
Minneapolis, Minn. Such dynamic stabilization systems typically
include a flexible member positioned between pedicle screws
installed in adjacent vertebrae of the spine. A flexible cord can
be threaded through the bore in the flexible member and secured to
the pedicle screws while cooperating with the flexible member to
permit mobility of the spine.
[0006] There is an ongoing need to provide alternative devices,
assemblies, systems and/or methods that can function to alleviate
pain or discomfort, provide stability, such as dynamic stability,
and/or restore a range of motion to a spinal segment of a spinal
column.
SUMMARY
[0007] The disclosure is directed to several alternative designs,
materials and methods of manufacturing medical device structures
and assemblies and uses thereof
[0008] Accordingly, one illustrative example is a spinal
stabilization system comprising an insert positionable in a channel
of a housing of a vertebral anchor and a support construct
including a spacer and first and second cords extendable through
the spacer. The insert has a first end positionable on a first side
of the housing of the vertebral anchor and a second end
positionable on a second side of the housing of the vertebral
anchor. The first and second cords are positionable through the
insert.
[0009] Additionally or alternatively, in another example, the
insert includes a first bore for receiving the first cord
therethrough and a second bore for receiving the second cord
therethrough.
[0010] Additionally or alternatively, in another example the system
includes a vertebral anchor including a housing defining a channel
and a fastener configured to rotatably engage the housing of the
vertebral anchor. Rotational engagement of the fastener with the
housing causes the fastener clamp both the first and second cords
in the insert.
[0011] Additionally or alternatively, in another example the
fastener directly contacts each of the first and second cords to
exert a clamping force directly on the first and second cords.
[0012] Additionally or alternatively, in another example the
fastener includes a threaded portion and a protuberance extending
from the threaded portion, wherein the protuberance is extendable
into an opening of the insert to contact each of the first and
second cords.
[0013] Additionally or alternatively, in another example the
opening intersects with each of the first and second bores.
[0014] Additionally or alternatively, in another example rotational
engagement of the fastener with the housing causes the fastener
clamp both the first and second cords in the insert and secure the
insert in the housing of the vertebral anchor.
[0015] Additionally or alternatively, in another example the first
bore extends parallel to and offset from the second bore, and the
opening extends perpendicular to and between the first and second
bores.
[0016] Additionally or alternatively, in another example the
vertebral anchor includes a threaded shaft extending from the
housing, wherein the threaded shaft has a lumen extending
therethrough for advancement over a K-wire.
[0017] Additionally or alternatively, in another example the
opening extends entirely through the insert such that the insert is
advanceable over the K-wire into the housing of the vertebral
anchor with the K-wire positionable between the first and second
cords.
[0018] Another illustrative example is a spinal stabilization
system including an insert securable to a housing of a vertebral
anchor, a support construct including a spacer and a cord
extendable through the spacer, and a clamping member. The insert
has a first flange positionable on a first side of the housing of
the vertebral anchor, a second flange positionable on a second side
of the housing of the vertebral anchor, and a medial portion
between the first and second flanges positionable in a channel of
the housing of the vertebral anchor. The cord is positionable
through a bore of the insert. The clamping member is movable
relative to the medial portion to clamp the cord in the bore of the
insert.
[0019] Additionally or alternatively, in another example the
clamping member includes a concave engagement surface configured to
press against a portion of the periphery of the cord, preferably 30
degrees or more of the periphery of the cord.
[0020] Additionally or alternatively, in another example the
clamping member includes a first tab movable in a channel in the
first flange and a second tab movable in a channel in the second
flange.
[0021] Additionally or alternatively, in another example the
clamping member is configured to be held in a loading position
prior to clamping onto the cord.
[0022] Additionally or alternatively, in another example each of
the channels has an upper portion having a first width and a lower
portion having a second width, the first width being less than the
width of the first and second tabs to form an interference fit with
the first and second tabs, and the second width being greater than
the width of the first and second tabs.
[0023] The above summary of some example embodiments is not
intended to describe each disclosed embodiment or every
implementation of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The invention may be more completely understood in
consideration of the following detailed description of various
embodiments in connection with the accompanying drawings, in
which:
[0025] FIG. 1 is a perspective view of an exemplary spinal
stabilization system;
[0026] FIG. 2 is an exploded perspective view of components of the
spinal stabilization system of FIG. 1, including an insert
positionable in a the channel of the housing of the pedicle
screw;
[0027] FIG. 3 is a perspective view of the insert of spinal
stabilization system of FIG. 1;
[0028] FIG. 4 is an exploded perspective view of the insert of FIG.
3;
[0029] FIG. 5A is a cross-sectional view of the insert positioned
in the housing of the pedicle screw of the spinal stabilization
system prior to securement of the insert in the housing;
[0030] FIG. 5B is a cross-sectional view of the insert secured in
the housing of the pedicle screw of the spinal stabilization
system;
[0031] FIGS. 6A through 6C illustrate exemplary configurations of
an insert of a spinal stabilization system;
[0032] FIG. 7 is a perspective view of another exemplary insert of
a spinal stabilization system;
[0033] FIG. 8 is a top view of the insert of FIG. 7;
[0034] FIG. 9 is a cross-sectional view of the insert taken along
line 9-9 of FIG. 8;
[0035] FIGS. 10A and 10B are longitudinal cross-sectional views of
the insert of FIG. 7 while securing a flexible cord within the
insert;
[0036] FIG. 10C is a longitudinal cross-sectional view of the
insert of FIG. 7 in an alternate orientation within a vertebral
anchor;
[0037] FIG. 11A is a perspective view of another exemplary insert
of a spinal stabilization system;
[0038] FIG. 11B is a longitudinal cross-sectional view of the
insert of FIG. 11A;
[0039] FIG. 12A is a perspective view of another exemplary insert
of a spinal stabilization system;
[0040] FIG. 12B is a perspective view of another exemplary insert
of a spinal stabilization system;
[0041] FIG. 13A is a perspective view of another exemplary insert
of a spinal stabilization system;
[0042] FIG. 13B is a perspective view of another exemplary insert
of a spinal stabilization system;
[0043] FIG. 14 is a perspective view of another exemplary insert
and associated locking member of a spinal stabilization system;
[0044] FIG. 15 is a longitudinal cross-sectional view of a spinal
stabilization system utilizing inserts as shown in FIG. 14;
[0045] FIG. 16 is a top view of a portion of the spinal
stabilization system of FIG. 15;
[0046] FIG. 17 is an exploded view of components of another spinal
stabilization system;
[0047] FIG. 18A is a longitudinal cross-sectional view of a spinal
stabilization system utilizing the components of FIG. 16;
[0048] FIG. 18B is an enlarged view of a portion of FIG. 17A;
[0049] FIG. 19 is a top view of a portion of the spinal
stabilization system of FIG. 17A;
[0050] FIG. 20 is an exploded view of components of another spinal
stabilization system;
[0051] FIG. 21 is a longitudinal cross-sectional view of the spinal
stabilization system of FIG. 19;
[0052] FIG. 22 is a perspective view of another spinal
stabilization system;
[0053] FIG. 23A is a longitudinal cross-sectional view of the
spinal stabilization system of FIG. 22;
[0054] FIG. 23B is an enlarged view of a portion of FIG. 23A;
[0055] FIG. 24 is a perspective view of an insert and associated
locking member of the spinal stabilization system of FIG. 22;
[0056] FIG. 25 is a cross-sectional view of the insert of FIG.
24;
[0057] FIG. 26 is a cross-sectional view of the insert of FIG. 25;
and
[0058] FIG. 27 is a cross-sectional view of the insert of FIG. 24
secured in the housing of a pedicle screw of the spinal
stabilization system of FIG. 23A.
[0059] While the invention is amenable to various modifications and
alternative forms, specifics thereof have been shown by way of
example in the drawings and will be described in detail. It should
be understood, however, that the intention is not to limit aspects
of the invention to the particular embodiments described. On the
contrary, the intention is to cover all modifications, equivalents,
and alternatives falling within the spirit and scope of the
invention.
DETAILED DESCRIPTION
[0060] For the following defined terms, these definitions shall be
applied, unless a different definition is given in the claims or
elsewhere in this specification.
[0061] All numeric values are herein assumed to be modified by the
term "about", whether or not explicitly indicated. The term "about"
generally refers to a range of numbers that one of skill in the art
would consider equivalent to the recited value (i.e., having the
same function or result). In many instances, the term "about" may
be indicative as including numbers that are rounded to the nearest
significant figure.
[0062] The recitation of numerical ranges by endpoints includes all
numbers within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75,
3, 3.80, 4, and 5).
[0063] Although some suitable dimensions ranges and/or values
pertaining to various components, features and/or specifications
are disclosed, one of skill in the art, incited by the present
disclosure, would understand desired dimensions, ranges and/or
values may deviate from those expressly disclosed.
[0064] As used in this specification and the appended claims, the
singular forms "a", "an", and "the" include plural referents unless
the content clearly dictates otherwise. As used in this
specification and the appended claims, the term "or" is generally
employed in its sense including "and/or" unless the content clearly
dictates otherwise.
[0065] The following detailed description should be read with
reference to the drawings in which similar elements in different
drawings are numbered the same. The detailed description and the
drawings, which are not necessarily to scale, depict illustrative
embodiments and are not intended to limit the scope of the
invention. The illustrative embodiments depicted are intended only
as exemplary. Selected features of any illustrative embodiment may
be incorporated into an additional embodiment unless clearly stated
to the contrary.
[0066] Referring now to FIG. 1, there is shown a spinal fixation
system 10 for stabilizing a portion of a spinal column, such as one
or more spinal segments of a spinal column. As used herein, a
spinal segment is intended to refer to two or more vertebrae, the
intervertebral disc(s) between the vertebrae and other anatomical
elements between the vertebrae. For example, a spinal segment can
include first and second adjacent vertebrae and the intervertebral
disc located between the first and second vertebrae. The spinal
stabilization system 10 can provide dynamic stabilization to a
spinal segment, preserving and/or allowing for a range of motion of
the spinal segment.
[0067] In some embodiments, the spinal stabilization system 10 can
be used to treat discogenic low back pain, degenerative spinal
stenosis, disc herniations, facet syndrome, posterior element
instability, adjacent level syndrome associated with spinal fusion,
and/or other maladies associated with the spinal column.
[0068] The spinal stabilization system 10 can include one or more
or a plurality of vertebral anchors, depicted as pedicle screws 12.
However, in some embodiments the vertebral anchors can be vertebral
hooks (e.g., laminar hooks) or other types of fastening members for
attachment to a bony structure such as a vertebra of the spinal
column. Each of the pedicle screws 12 can be configured to be
secured to a vertebra of a spinal column. For instance, the first
pedicle screw 12a can be secured to a first vertebra and the second
pedicle screw 12b can be secured to a second vertebra. Additional
pedicle screws 12 can be present in instances in which the spinal
stabilization system 10 spans three or more vertebra of the spinal
column.
[0069] The pedicle screw 12 can include a housing 14 and a shaft
16, which can include threads 18, extending from the housing 14.
The housing 14 can include a channel, such as a U-shaped channel
extending from one side of the housing 14 to an opposite second
side of the housing 14. The channel 15 (see FIG. 2) can be defined
between opposing legs of the housing 14. The shaft 16 can be
configured to be installed into a bony region of a vertebra of the
spinal column. For example, the shaft 16 can be installed into a
pedicle of a vertebra, or other region of a vertebra. The shaft 16
can extend along a longitudinal axis. The pedicle screw 12 depicted
in the Figures is a poly-axial pedicle screw which allows the
housing 14 to be pivotable relative to the shaft 16 to a plurality
of angular positions relative to the longitudinal axis. The pedicle
screw 12, as shown in FIG. 2, can include a head portion 17 at the
end of the shaft 16 which is received in the housing 14. The
housing 14 can be pivotable relative to the head portion 17 of the
shaft 16. In other instances, the pedicle screw 12 can be
mono-axial or mono-planar, if desired.
[0070] The pedicle screw 12 can include a securing element, such as
a threaded fastener 20 (e.g., a set screw, cap) configured to
rotatably engage the housing 14 to secure a portion of a support
construct 22 to the pedicle screw 12. For example, the threaded
fastener 20 can include threads which mate with threads formed in
the housing 14. In other embodiments, the fastener 20 can include
one or more flanges, cam surfaces, or other engagement features
that engage with one or more channels, grooves, surfaces, or other
engagement features of the housing 14 through rotation of the
fastener 20. The fastener 20 can be rotatably engaged between
spaced apart legs of the housing 14 which define the channel 15 of
the housing 14 therebetween.
[0071] The spinal stabilization system 10 can also include one or
more, or a plurality of support constructs 22 extending between
pedicle screws 12 of the spinal stabilization system 10. As an
illustrative example, the spinal stabilization system 10 shown in
FIG. 1 includes a support construct 22 extending between the first
pedicle screw 12a and the second pedicle screw 12b.
[0072] The support construct 22 can be constructed of a plurality
of components in some instances. For instance, the support
construct 22 can include a spacer 24, and a flexible member such as
a flexible cord 30 extending through the spacer 24, as well as
other components if desired.
[0073] In some embodiments, the spacer 24 can be an annular spacer
having a lumen (not shown) extending from a first end 26 to a
second end 28 of the spacer 24. For example, in some embodiments
the spacer 24 can be a cylindrical member having a lumen extending
therethrough. In other embodiments, the spacer 24 can be molded,
extruded, or otherwise formed over and/or around the cord 30. The
spacer 24 can be positioned between the housing 14 of the first
pedicle screw 12a and the housing 14 of the second pedicle screw
12b. In some embodiments, the spacer 24 can be formed from
polycarbonate urethane (PCU), although it will be recognized that
various other materials suitable for implantation within the human
body and for providing stabilization of the spine while maintaining
flexibility can be used. In other embodiments, the spacer 24 can be
constructed of other materials such as metal, polymeric materials,
or combinations of materials.
[0074] The cord 30 can extend from the housing 14 of the first
pedicle screw 12a to the housing 14 of the second pedicle screw
12b. In one embodiment, the cord 30 can be formed from
polyethylene-terephthalate (PET), although it will be recognized
that various other materials suitable for implantation within the
human body and for providing stabilization of the spine while
maintaining flexibility can be used. In other embodiments, the cord
30 can be constructed of other flexible materials such as metal,
polymeric materials, or combinations of flexible materials. It is
noted that during a medical procedure the portions of the cord 30
which are shown extending from the channels of the pedicle screws
12a, 12b can be trimmed as desired to reduce and/or eliminate the
portion of the cord 30 extending from the pedicle screws 12a,
12b.
[0075] When implanted in a patient, the cord 30 of the spinal
stabilization system 10 can limit the range of flexion of the
spinal segment, whereas the spacer 24 can limit the range of
extension of the spinal segment. For instance, the cord 30 can be
placed in tension and the spacer 24 can be placed in compression
between the pedicle screws 12a, 12b.
[0076] The spinal stabilization system 10 can also include inserts
32 configured to be inserted into the channels 15 of the housings
14 of the pedicle screws 12. One possible embodiment of the insert
32 is further illustrated in FIGS. 3 and 4. The inserts 32, which
can be considered spools in some instances, can include a first
flange 34 proximate a first end of the insert 32, a second flange
36 proximate the second end of the insert 32, and a medial portion
38 intermediate the first flange 34 and the second flange 36 and
extending therebetween. The insert 32 can have end surfaces 48
configured to abut an end surface of the spacer 24. For instance,
when assembled an end surface 48 of an insert 32 coupled with the
first pedicle screw 12a can abut an end surface of the spacer 24
proximate the first end 26 of the spacer 24 and an end surface 48
of an insert 32 coupled with the second pedicle screw 12b can abut
an end surface of the spacer 24 proximate the second end 28 of the
spacer 24.
[0077] The insert 32 can be configured such that the medial portion
38 is positionable in the channel 15 (shown in FIG. 2) of the
housing 14 of the pedicle screw 12 with the first flange 34
positioned exterior of the housing 14 and facing the first side of
the housing 14 and the second flange 36 positioned exterior of the
housing 14 and facing the second side of the housing 14. The insert
32 can be positioned in the channel 15 in a top-loaded fashion in
which the insert 32 is moved into the channel 15 of the housing 14
in a direction generally perpendicular to the longitudinal axis of
the channel 15 of the housing 14.
[0078] The insert 32 can include bore 40 extending from a first end
surface 48 at the first end of the insert 32 to a second end
surface 48 at the second end of the insert 32 along a longitudinal
axis through the insert 32. The bore 40 can be configured to
receive the cord 30 therein. For instance, the cord 30 can be
inserted into and/or through the bore 40 of the insert 32. Thus,
the cord 30 can extend out of the bore 40 from the first end
surface 48 at the first end of the insert 32 in a first direction
and/or the cord 30 can extend out of the bore 40 from the second
end surface 48 at the second end of the insert 32 in a second
direction opposite the first direction.
[0079] The insert 32 can include a clamping member 50 configured to
clamp or secure the cord 30 within the bore 40 of the insert 32.
For example, the clamping member 50 can be inserted into an opening
42 in the medial portion 38 of the insert 32 to bear against the
cord 30. The opening 42 can intersect with the bore 40 to provide
direct engagement of the clamping member 50 with a portion of the
cord 30 positioned in the bore 40. In some instances, the insert 32
can be press fit in the opening 42. As shown in FIG. 3, in some
instances, the clamping member 50 can be inserted into the opening
42 until the exterior surface of the clamping member 50 is flush
with an exterior surface of the medial portion 38 of the insert
32.
[0080] The clamping member 50 can include any mechanical gripping
means such as, but not limited to, one or more ribs, projecting
grooves, teeth, posts, spikes, and/or serrations or combination
thereof for engaging and/or penetrating into the cord 30. In the
illustrated embodiment, the clamping member 50 can include a
generally concave engagement surface 44 having a plurality of ribs,
teeth, serrations, grooves, or other gripping features formed along
the concave surface 44, configured to engage and/or penetrate into
the cord 30. As shown in FIG. 5A, the concave engagement surface 44
can be configured to engage the periphery of the cord 30, such as
30 degrees or more, 45 degrees or more, 60 degrees or more, 75
degrees or more, or 90 degrees or more around the periphery (e.g.,
circumference) of the cord 30 when engaging the cord 30 in the bore
40.
[0081] In some instances, the cord 30 can be pre-assembled with the
insert 32 and secured in the bore 40 with the clamping member 50 by
pressing the clamping member 50 against the cord 30 prior to
inserting the insert 32 into the channel 15 of the housing 14 of
the pedicle screw 12. Additionally or alternatively, the cord 30
can be intra-operatively secured in the bore 40 with the clamping
member 50 while securing the insert 32 in the channel 15 of the
housing 14 of the pedicle screw 12 with the fastener 20.
[0082] One exemplary configuration for securing the cord 30 in the
bore 40 while simultaneously locking the housing 14 of the
poly-axial pedicle screw 12 from pivotal movement is shown in FIGS.
5A and 5B.
[0083] As shown in FIG. 5A, the insert 32 can be inserted into the
channel 15 of the housing 14 in a direction generally perpendicular
to the longitudinal axis of the bore 40. The cord 30, extending
into or through the bore 40 of the insert 32, can also be inserted
into the channel 15 of the housing 14 with the cord 30 extending
from the first side of the housing 14 and/or extending from the
second side of the housing 14. Thus, the medial portion 38 of the
insert 32 can be positioned within the U-shaped channel 15.
[0084] The fastener 20 can then be engaged with the housing 14,
such as through rotational movement of the fastener 20 relative to
the housing 14. In some instances, the fastener 20 can include a
threaded portion which threadably engages a threaded portion of the
housing 14, such as internally threaded portions of opposing legs
of the housing 14 defining the channel 15. Rotational movement of
the fastener 20 moves the fastener 20 into engagement with the
insert 32.
[0085] As shown in FIG. 5B, rotational engagement of the fastener
20 with the housing 14 causes the fastener 20 to directly contact
the clamping member 50 to exert a force on the clamping member 50
to push the clamping member 50 toward the cord 30. The amount of
rotation of the fastener 20, and thus axial movement of the
fastener 20 along its axis of rotation, controls the displacement
of the clamping member 50 in the opening 42 toward the cord 30. The
concave surface 44 of the clamping member 50 can contact a portion
of the periphery (e.g., circumference) of the cord 30, such as 5%
or more, 10% or more, 15% or more, 20% or more, or 25% or more of
the periphery of the cord 30. Deformation of the cord 30 and/or
penetration into the cord 30 by the clamping member 50 can prevent
the cord 30 from moving axially through the bore 40 of the insert
32.
[0086] In some instances, the clamping force generated through
rotational engagement of the fastener 20 with the housing 14 both
clamps the cord 30 to the insert 32 (and thus secures the cord 30
to the pedicle screw 12) and locks the housing 14 from pivotal
movement relative to the shaft 16 of the pedicle screw 12. For
instance a locking force exerted by the fastener 20 can be
transmitted through the insert 32 to the head portion 17 of the
shaft 16 to lock the housing 14 from pivotable movement relative to
the head portion 17 of the shaft 16. When the clamping force is
sufficiently large, the clamping force exerted onto the head
portion 17 by the insert 32 locks the housing 14 from pivotal
movement relative to the head portion 17.
[0087] As shown in FIGS. 6A-6C, the end surfaces 48 of the insert
32 can be oriented at any desired angle relative to the
longitudinal axis of the bore 40 extending through the insert 32.
For example, in FIG. 6A, the both the first and second end surfaces
48 of the insert 32 can be generally perpendicular to the
longitudinal axis of the bore 40. In other instances, one or more
of the end surfaces 48 can be oriented at an oblique angle to the
longitudinal axis of the bore 40, such as for use in lordotic
applications. For example, in FIG. 6B, the first end surface 48 of
the insert 32 can be at an oblique angle .theta. to the
longitudinal axis of the bore 40, while the second end surface 48
of the insert can be generally perpendicular to the longitudinal
axis of the bore 40. Alternatively, in FIG. 6C, the first end
surface 48 of the insert 32 can be at an oblique angle
.theta..sub.1 to the longitudinal axis of the bore 40 and the
second end surface 48 of the insert 32 can be at an oblique angle
.theta..sub.2 to the longitudinal axis of the bore 40. The angles
.theta..sub.1 and .theta..sub.2 can be the same or different. The
angles .theta..sub.1, .theta..sub.2 and/or .theta. can be any
desired angle, such as 2.degree., 3.degree., 4.degree., 5.degree.,
6.degree., 7.degree., 8.degree., 9.degree. or 10.degree., for
example. It is note that any of the embodiments of an insert
described herein can include end surfaces which are perpendicular
and/or oblique to the longitudinal axis of the bore extending
through the insert.
[0088] Another embodiment of an insert 132 configured for
securement of the cord 30 within the housing 14 of a pedicle screw
12 or other vertebral anchor is illustrated in FIGS. 7-9. The
insert 132 can be similar to the insert 32 in many respects. For
example, the insert 132 can include a first flange 134 proximate a
first end of the insert 132, a second flange 136 proximate the
second end of the insert 132, and a medial portion 138 intermediate
the first flange 134 and the second flange 136 and extending
therebetween. The insert 132 can have end surfaces 148 configured
to abut an end surface of the spacer 24. The insert 132 can be
configured such that the medial portion 138 is positionable in the
channel 15 of the housing 14 of the pedicle screw 12 with the first
flange 134 positioned exterior of the housing 14 and facing the
first side of the housing 14 and the second flange 136 positioned
exterior of the housing 14 and facing the second side of the
housing 14.
[0089] The insert 132 can include bore 140 extending from a first
end surface 148 at the first end of the insert 132 to a second end
surface 148 at the second end of the insert 132 along a
longitudinal axis through the insert 132. The bore 140 can be
configured to receive the cord 30 therein.
[0090] The insert 132 can include a clamping member 150 configured
to clamp or secure the cord 30 within the bore 140 of the insert
132. For example, the clamping member 150 can be movable relative
to the medial portion 138 of the insert 132 to bear against the
cord 30 and clamp the cord 30 therebetween. The clamping member 150
can include a first tab 152 extending into a channel 146 in the
first flange 134 and a second tab 152 extending into a channel 146
in the second flange 136. The tabs 152 can move along the channels
146 as the clamping member 150 is moved toward the cord 30 to clamp
the cord 30 in the bore 140. In some instances, such as shown in
FIG. 8, the tabs 152 can form an interference fit with the channels
146 such that walls of the tabs 152 frictionally engage walls of
the channels 146 to resist movement of the clamping member 150
relative to the medial portion 138 of the insert 132 unless and
until the force sufficient to overcome the frictional/interference
force is overcome. As shown in FIG. 9, in some instances the upper
portion of the channels 146 can have a width W.sub.1 and a lower
portion of the channels 146 can have a width W.sub.2 greater than
the width W.sub.1. The tabs 152 can have a width greater than the
width W.sub.1 to provide an interference fit in the upper portion
of the channel 146. However, the width of the tabs 152 can be less
than the width W.sub.2 of the lower portion of the channel 146.
Thus, as shown in FGI. 10A, the clamping member 150 can be
initially positioned in a first, loading position with the tabs 152
forming an interference fit in the upper portion of the channel
146, retaining the clamping member 150 in the loading position such
that the clamping member 150 does not interfere with positioning
the cord 30 into and/or through the bore 140 of the insert 132.
Upon applying sufficient force to the clamping member 150 to
overcome the frictional force (e.g., tightening the fastener 20 in
the housing 14 of the pedicle screw 12 to apply a force against the
clamping member 150), the tabs 152 move into the wider lower
portion of the channel 146 to the clamped position, shown in FIG.
10B, with the clamping member 150 engaging and/or penetrating into
the cord 30 to secure the cord 30 in the bore 140 of the insert
132.
[0091] It is noted that other configurations are contemplated for
initially holding the clamping member 150 in a loading position to
facilitate positioning the cord 30 in the bore 140. For example,
detents can be incorporated with the tabs 152/channels 146 to form
an interference between the components.
[0092] The clamping member 150 can include any mechanical gripping
means such as, but not limited to, one or more ribs, projecting
grooves, teeth, posts, spikes, and/or serrations or combination
thereof for engaging and/or penetrating into the cord 30. In the
illustrated embodiment of FIGS. 10A-10C, the clamping member 150
can include a generally concave engagement surface having a
plurality of ribs, teeth, serrations, grooves, or other gripping
features formed along the concave surface, configured to engage
and/or penetrate into the cord 30. The concave engagement surface
can be configured to engage the periphery of the cord 30, such as
30 degrees or more, 45 degrees or more, 60 degrees or more, 75
degrees or more, or 90 degrees or more around the periphery (e.g.,
circumference) of the cord 30 when engaging the cord 30 in the bore
140.
[0093] Additionally or alternatively to the embodiment of FIGS.
10A-10C, the medial portion 138 of the insert 132 can include any
mechanical gripping means such as, but not limited to, one or more
ribs, projecting grooves, teeth, posts, spikes, and/or serrations
or combination thereof for engaging and/or penetrating into the
cord 30. In the illustrated embodiment of FIG. 12B, the medial
portion 138 can include a generally concave engagement surface
having a plurality of ribs, teeth, serrations, grooves, or other
gripping features formed along the concave surface, configured to
engage and/or penetrate into the cord 30. The concave engagement
surface can be configured to engage the periphery of the cord 30,
such as 30 degrees or more, 45 degrees or more, 60 degrees or more,
75 degrees or more, or 90 degrees or more around the periphery
(e.g., circumference) of the cord 30 when engaging the cord 30 in
the bore 140.
[0094] In some instances, the cord 30 can be pre-assembled with the
insert 132 and secured in the bore 140 with the clamping member 150
by pressing the clamping member 150 against the cord 30 prior to
inserting the insert 132 into the channel 15 of the housing 14 of
the pedicle screw 12. Additionally or alternatively, the cord 30
can be intra-operatively secured in the bore 140 with the clamping
member 150 while securing the insert 132 in the channel 15 of the
housing 14 of the pedicle screw 12 with the fastener 20.
[0095] FIG. 10C illustrates another possible orientation of the
insert 132 positioned in the channel of the housing 14 of a pedicle
screw (shown in phantom). As shown in FIG. 10C, in some instances
the insert 132 can be positioned in the channel of the housing 14
of the pedicle screw 12 with the clamping member 150 below or
distal the medial region 138 of the insert 132, with the flanges
134, 136 positioned on opposite sides of the housing 14, if
desired. Upon applying sufficient force to the clamping member 150
to overcome the frictional force between the tabs 152 and channels
146 (e.g., tightening the fastener 20 in the housing 14 of the
pedicle screw 12 to apply a force against the medial region 138),
the medial region 138 and first and second flanges 134, 136 move
downward relative to the housing 14 to clamp the cord 30 between
the medial region 138 and clamping member 150. As the medial region
138 and flanges 134, 136 move relative to the housing 14 and
clamping member 150, the tabs 152 move into the wider lower portion
of the channel 146 to the clamped position, with the clamping
member 150 engaging and/or penetrating into the cord 30 to secure
the cord 30 in the bore 140 of the insert 132. Accordingly, in some
instances the fastener 20 can bear against the medial region 138 of
the insert 132 while the clamping member 150 can bear against a
component of the housing 14, for example.
[0096] FIGS. 11A and 11B illustrate insert 132', which is a
variation of the insert 132. Unlike the embodiment of FIGS. 7-8, in
which the channels 146 extend to the outer peripheral edge of the
flanges 134, 136, in the variation of FIGS. 11A and 11B, the
channels 146 may not extend to the outer peripheral edge of the
flanges 134, 136. Such an embodiment can help retain the clamping
member 150 assembled with the main body of the clamping member 150
during assembly of the construct. FIGS. 12A and 12B illustrate
insert 132'', which is a variation of the insert 132' illustrating
that the width of the channels 146 and tabs 152 can be up to about
the diameter of the bore 140.
[0097] FIGS. 13A and 13B illustrate insert 132''', which is a
variation of the insert 132''. Unlike the embodiment of FIGS.
12A-12B, in which the channels 146 and tabs 152 each have a uniform
width, in the variation of FIGS. 13A and 13B, the upper portion of
the channels 146 can have a protuberance extending radially towards
the bore 140 and the tabs 152 can have a void disposed therein that
receives the protuberance in mating engagement.
[0098] It is noted that in other instances, the insert 132, 132'
can include channels at opposing ends of the clamping member 150
configured to mate with and receive projections extending into the
channels from the flanges 134, 136. In other instances, the insert
132, 132' can include a channel at a first end of the clamping
member 150 configured to mate with and receive a projection
extending into the channels from one of the flanges 134, 136 and a
tab extending from the opposite, second end of the clamping member
150 configured to mate with and extend into a channel in the other
of the flanges 134, 136.
[0099] Another embodiment of an insert 232 configured for
securement of the cord 30 within the housing 14 of a pedicle screw
12 or other vertebral anchor is illustrated in FIG. 13. The insert
232 can be similar to the insert 32 in many respects. For example,
the insert 232 can include a first flange 234 proximate a first end
of the insert 232, a second flange 236 proximate the second end of
the insert 232, and a medial portion 238 intermediate the first
flange 234 and the second flange 236 and extending therebetween.
The insert 232 can have end surfaces 248 configured to abut an end
surface of the spacer 24. The insert 232 can be configured such
that the medial portion 238 is positionable in the channel 15 of
the housing 14 of the pedicle screw 12 with the first flange 234
positioned exterior of the housing 14 and facing the first side of
the housing 14 and the second flange 236 positioned exterior of the
housing 14 and facing the second side of the housing 14.
[0100] The insert 232 can include bore 240 extending from a first
end surface 248 at the first end of the insert 232 to a second end
surface 248 at the second end of the insert 232 along a
longitudinal axis through the insert 232. The bore 240 can be
configured to receive the cord 30 therein.
[0101] The insert 232 can include an opening 242 in the medial
portion 238 of the insert 232 for receiving a clamping member to
bear against the cord 30. The opening 242 can intersect with the
bore 240 to provide direct engagement of the clamping member with a
portion of the cord 30 positioned in the bore 240. The clamping
member can be a fastener 220, such as a threaded set screw
including threads which mate with threads formed in the housing 14.
The fastener 220 can be rotatably engaged between spaced apart legs
of the housing 14 to apply a clamping force to the cord 30 to clamp
or secure the cord 30 within the bore 240 of the insert 232 while
simultaneously clamping the insert 232 in the housing 14 of a
pedicle screw 12. For example, the fastener 220 can include a
threaded portion 226 and a protuberance 224 extending from the
threaded portion 226. The protuberance 224 can extend into the
opening 242 to bear against the cord 30 and clamp the cord 30 in
the bore 240.
[0102] The insert 232 can also include recesses 260 formed in the
flanges 234, 236 of the insert 232 to accommodate the fastener 220
therebetween. For instance, as shown in FIG. 16, the fastener 220
can have an outer diameter greater than the distance between the
first flange 234 and the second flange 236 (i.e., the distance
between the inner surfaces of the flanges 234, 236 facing the
medial portion 238. Thus, the recesses 260 can provide clearance
for the fastener 220 to be rotatably engaged with the housing 14 of
the pedicle screw 12 between the first and second flanges 234, 236.
Furthermore, the recesses 260 can allow for a degree of rotational
variability of the insert 232 (about the longitudinal axis of the
bore 240) relative to the housing 14 when positioning and securing
the insert 232 in the housing 14.
[0103] FIG. 15 illustrates a support construct 222 utilizing
inserts 232. The support construct 222 can also include spacers 24
and a flexible member such as a flexible cord 30 extending through
the spacers 24, as well as other components if desired. The inserts
232 are shown positioned in the housing 14 of the pedicle screws
12, with spacers 24 positioned between facing surfaces of the
inserts 232. The flexible cord 30 can extend through the bores 240
of the inserts 232 and the lumen of the spacers 24. The fasteners
220 can be threadably engaged with the housing 14 of the pedicle
screws 12 to secure the inserts 232 to the housing 14 while the
protuberance 224 of the inserts 232 can simultaneously engage the
cord 30 to secure the cord 30 relative to the insert 232 and
housing 14.
[0104] Furthermore, the end of the cord 30 can be secured to a
rigid rod member 270, providing a transition between the dynamic or
flexible portion of the construct 222 and a rigid portion of the
construct 222. The rigid rod 270 can extend to one or more
additional pedicle screws (not shown), for example.
[0105] The rigid rod member 270 can include an end region
configured to be secured to an end region of the cord 30. For
example, end region of the rigid rod member 270 can be configured
as a clam shell connector having a plurality of segments 272
collectively defining a bore for receiving the end region of the
cord 30. The segments 272 can extend from a flange 274 of the rigid
rod member 270 positionable on a first side of the housing 14 of
the pedicle screw 12. The free ends of the segments 272 can move
toward one another (e.g., radially inward toward the central
longitudinal axis of the cord 30 to clamp around the cord 30. For
example, a clamping force can be exerted on the segments 272 to
move the free ends toward one another. A retaining ring 276 can be
slid over the cord 30 and placed around the free ends of the
segments 272 to secure the cord 30 and prevent the free ends of the
segments 272 from separating. The segments 272 of the clam shell
connector can be positioned in the channel of the housing 14 of the
pedicle screw 12 with the flange 274 on a first side of the housing
14 and the retaining ring 276 on a second, opposite side of the
housing 14. The retaining ring 276 can act as a flange for
engagement with a spacer 24 of the support construct 222.
[0106] Components of another exemplary support construct 322
utilizing inserts 332 are shown in FIG. 17. It is noted that the
inserts 332 can be substituted with any other configuration of
insert described herein, if desired. The support construct 322
includes inserts 332 for securement in the housings 14 of pedicle
screws 12 or other vertebral anchors, as well as spacers 24 and a
flexible member such as a flexible cord 30 extending through the
spacers 24 and secured in the inserts 332.
[0107] The inserts 332 can be similar to the other inserts 332
described herein in many respects. For example, the inserts 332 can
include a first flange 334 proximate a first end of the insert 332,
a second flange 336 proximate the second end of the insert 332, and
a medial portion 338 intermediate the first flange 334 and the
second flange 336 and extending therebetween. The insert 332 can be
configured such that the medial portion 338 is positionable in the
channel 15 of the housing 14 of the pedicle screw 12 with the first
flange 334 positioned exterior of the housing 14 and facing the
first side of the housing 14 and the second flange 336 positioned
exterior of the housing 14 and facing the second side of the
housing 14.
[0108] The insert 332 can include bore 340 extending from a first
end surface at the first end of the insert 332 to a second end
surface at the second end of the insert 332 along a longitudinal
axis through the insert 332. The bore 340 can be configured to
receive the cord 30 therein.
[0109] The insert 332 can include one or more, or a plurality of
openings 342 in the medial portion 338 of the insert 332 for
receiving a clamping member to bear against the cord 30. The
openings 342 can intersect with the bore 340 to provide direct
engagement of the clamping member with a portion of the cord 30
positioned in the bore 340. The clamping members can be pins 350
press fit, or otherwise positioned in the openings 342.
[0110] The insert 332 can also include recesses 360 formed in the
flanges 334, 336 of the insert 332 to accommodate the fastener 20
therebetween. For instance, as shown in FIG. 19, the fastener 20
can have an outer diameter greater than the distance between the
first flange 334 and the second flange 336 (i.e., the distance
between the inner surfaces of the flanges 334, 336 facing the
medial portion 338. Thus, the recesses 360 can provide clearance
for the fastener 20 to be rotatably engaged with the housing 14 of
the pedicle screw 12 between the first and second flanges 334,
336.
[0111] FIG. 18A illustrates a support construct 322 utilizing
inserts 332. The support construct 322 can also include spacers 24
and a flexible member such as a flexible cord 30 extending through
the spacers 24, as well as other components if desired. The inserts
332 are shown positioned in the housing 14 of the pedicle screws
12, with spacers 24 positioned between adjacent inserts 332. The
flexible cord 30 can extend through the bores 340 of the inserts
332 and the lumen of the spacers 24. The fasteners 20 can be
threadably engaged with the housing 14 of the pedicle screws 12 to
secure the inserts 332 to the housing 14. In some instances, the
fasteners 20 can drive the pins 350 into clamping engagement with
the cord 30 as the fasteners 20 are threadably engaged with the
housing 14 of the pedicle screw 12. In other instances, the drive
pins 350 can be pressed against the cord 30 prior to inserting the
inserts 332 into the housing 14 of the pedicle screw 12.
[0112] The support construct 322 can also include one or more rings
380 positionable between an end surface of an insert 332 and an end
surface of a spacer 24. In some instances, the use of the ring 380
can between the insert 332 and the spacer 24 can provide a desired
amount of angulation between the longitudinal axis of the bore 340
of the insert 332 relative to the lumen of the spacer 24 such that
the central axis of the lumen of the spacer 24 extends non-parallel
(e.g., oblique) to the central axis of the bore 340 of the insert
332.
[0113] As shown in in the enlarged view of FIG. 18B, the ring 380
can include an annular portion 382 with an opening 388 extending
axially through the annular portion 382 for receiving the cord 30
therethrough. The annular portion 382 can have a first face 392
configured to face and abut an end surface of a flange of the
insert 332 and an opposite, second face 394 configured to face and
abut an end surface of a spacer 24. The first face 392 can be
non-parallel to the second face 394 providing the annular portion
382 with a wedge-shape. The angle between the first face 392 and
the second face 394 can be any desired angle, such as 2.degree.,
3.degree., 4.degree., 5.degree., 6.degree., 7.degree., 8.degree.,
9.degree. or 10.degree., for example.
[0114] In some instances the ring 380 can include an annular
projection 384 extending from the second face 394 of the annular
portion 382. The opening 388 can extend through the annular
projection 384, and thus the cord 30 can extend through the annular
projection 384. The annular projection 384 can be configured to
extend into the lumen of the spacer 24, such as an enlarged
recessed portion at an end region of the spacer 24. Additionally or
alternatively, the ring 380 can include annular projection 386
extending from the first face 392 of the annular portion 382. The
opening 388 can extend through the annular projection 386, and thus
the cord 30 can extend through the annular projection 386. The
annular projection 386 can be configured to extend into the bore
340 of the insert 332, such as an enlarged recessed portion in a
flange of the insert 332.
[0115] In some instances, the ring 380 can include an engagement
feature configured to mate with an engagement feature of the insert
332 and/or the spacer 24 to orient the ring 380 at a desired
rotational position relative to the insert 332 positioned on a
first side of the ring 380 and/or the spacer 24 positioned on a
second side of the ring 380.
[0116] FIGS. 20 and 21 illustrate components of another support
construct 422 including a rigid segment coupled to a flexible
segment. The support construct 422 can include an insert 432
positionable in the housing 14 of a pedicle screw 12 or other
vertebral anchor, forming a transition between a rigid segment and
a flexible segment of the support construct 422. For example, the
rigid segment can include a rigid rod member 470 and the flexible
segment can include a spacer 24, and a flexible member such as a
flexible cord 30 extending through the spacer 24, as well as other
components if desired. The end of the cord 30 can be secured to the
rigid rod member 470, via the insert 432, providing a transition
between the dynamic or flexible portion of the construct 422 and
the rigid portion of the construct 422.
[0117] The insert 432 can include a first flange 434 and a second
flange 436 spaced from the first flange 434 by a medial region 438.
The medial region 438 can have a cross-sectional dimension less
than the cross-sectional dimension of each of the first and second
flanges 434, 436. For instance, the medial region 438 can be sized
for insertion into the U-shaped channel of the housing 14 of a
pedicle screw 12 or other vertebral anchor, with the first flange
434 located exterior of the housing 14 on a first side of the
housing 14 and the second flange 436 located exterior of the
housing 14 on a second side of the housing 14, similar to other
inserts described herein.
[0118] The rigid rod member 470 can extend from the second flange
436. In some instances the rigid rod member 470 can be integrally
formed with the insert 432 as a monolithic construct, however, in
other instances the rigid rod member 470 can be a separate
component attached to the insert 432, for example. The rigid rod
470 can be sized to extend to one or more additional pedicle screws
(not shown), for example. The rigid rod 470 can be any desired
length, such as a length sufficient to extend between two, three,
four, or more pedicle screws 12 secured to corresponding vertebrae
of the spinal column.
[0119] The insert 432 can include a bore 440 extending into the
medial region 438 from the first flange 434 for receiving a portion
of the flexible cord 30, such as an end portion of the flexible
cord 30. The insert 432 can also include a clamping member 450
configured to clamp or secure the cord 30 within the bore 440 of
the insert 432. For example, the clamping member 450 can be movable
relative to the medial portion 438 of the insert 432 to clamp the
cord 30 between the clamping member 450 and the medial portion
438.
[0120] The clamping member 450 can be constructed similar to the
clamping member 150, discussed above. For example, the clamping
member 450 can include a first tab 452 extending into a channel 446
in the first flange 434 and a second tab 452 extending into a
channel 446 in the second flange 436. The tabs 452 can move along
the channels 446 as the clamping member 450 is moved toward the
cord 30 to clamp the cord 30 in the bore 440. In some instances,
the tabs 452 can form an interference fit with the channels 446
such that walls of the tabs 452 frictionally engage walls of the
channels 446 to resist movement of the clamping member 450 relative
to the medial portion 438 of the insert 432 unless and until the
force sufficient to overcome the frictional/interference force is
overcome.
[0121] The clamping member 450 can include any mechanical gripping
means such as, but not limited to, one or more ribs, projecting
grooves, teeth, posts, spikes, and/or serrations or combination
thereof for engaging and/or penetrating into the cord 30. In the
illustrated embodiment, the clamping member 450 can include one or
more, or a plurality of protuberances 454 configured to engage
and/or penetrate into the cord 30.
[0122] It is noted that the insert 432 can alternatively be
constructed to use any other clamping member to secure the cord 30
in the bore 440, such as any of the other clamping members
described herein. Furthermore, it is noted that any of the other
inserts described herein can include a rigid rod portion extending
from one end of the insert for forming a rigid construct between
two or more vertebrae.
[0123] FIG. 21 is a cross-sectional view of the support construct
422 in an assembled configuration, with the medial portion 438
positioned in the U-shaped channel of the housing 14 of a pedicle
screw 12 and the flanges 434, 436 positioned on either side of the
housing 14. In the assembled configuration, an end portion of the
flexible cord 30 is positioned in the bore 440 of the insert 432
and the clamping member 450 is pressed into engagement with the
cord 30 with the fastener 20.
[0124] The fastener 20 can then be engaged with the housing 14,
such as through rotational movement of the fastener 20 relative to
the housing 14. In some instances, the fastener 20 can include a
threaded portion which threadably engages a threaded portion of the
housing 14, such as internally threaded portions of opposing legs
of the housing 14 defining the channel 15. Rotational movement of
the fastener 20 moves the fastener 20 into engagement with the
clamping member 450.
[0125] Although not shown, the rigid rod member 470 can extend to
one or more additional pedicle screws which can be secured to
corresponding vertebrae of the spinal column. Furthermore, the cord
30 can extend in an opposite direction from the insert 432 to one
or more additional pedicle screws which can be secured to vertebrae
of the spinal column. Furthermore, a spacer 24, such as that shown
in FIG. 20, can be positioned between the flange 434 and another
insert 432 and/or pedicle screw with the flexible cord 30 extending
through the spacer 24, to provide a flexible construct at one or
more vertebral levels.
[0126] Another spinal fixation system 510 for stabilizing a portion
of a spinal column, such as one or more spinal segments of a spinal
column is shown in FIG. 22. The spinal stabilization system 510 can
include one or more or a plurality of vertebral anchors, depicted
as pedicle screws 12, configured to be secured to a vertebra of a
spinal column. The pedicle screws 12 can include a housing 14 and a
shaft 16, which can include threads, extending from the housing 14.
The pedicle screws 12 can be poly-axial, mono-axial or mono-planar,
if desired. As shown in the cross-sectional view of FIG. 23A, the
pedicle screws 12 can be cannulated (e.g., the threaded shaft 16
can having a central lumen extending longitudinally therethrough)
to be delivered to the anatomy over a K-wire 590.
[0127] The pedicle screw 12 can include a securing element, such as
a threaded fastener 520 (e.g., a set screw, cap) configured to
rotatably engage the housing 14 to secure a portion of a support
construct 522 to the pedicle screw 12. The fastener 520 can be
rotatably engaged between spaced apart legs of the housing 14 which
define a channel of the housing 14 therebetween. The fastener 520
can also be cannulated to be advanced to the housing 14 of the
pedicle screw along a K-wire 590
[0128] The spinal stabilization system 510 can also include one or
more, or a plurality of support constructs 522 extending between
pedicle screws 12 of the spinal stabilization system 510. The
support construct 522 can be constructed of a plurality of
components in some instances. For instance, the support construct
522 can include spacers 24, and a plurality of flexible members
such as a first flexible cord 530a and a second flexible cord 530b
extending through the spacers 24, as well as other components if
desired. The cords 530a, 530b can extend from the housing 14 of the
first pedicle screw 12 to the housing 14 of the second pedicle
screw 12.
[0129] In some embodiments, the spacers 24 can have a lumen
extending from a first end to a second end of the spacer 24, as
shown in FIG. 23A, for receiving the first and second flexible
cords 530a, 530b therethrough. In other instances, the spacers 24
can include a plurality of lumens extending therethrough, each
configured to receive a separate one of the plurality of flexible
cords, for example. For instance, the spacer can include a first
lumen configured to receive the first flexible cord 530a and a
second lumen configured to receive the second flexible cord 530b,
maintaining the first and second flexible cords 530a, 530b isolated
from one another through the spacer 24.
[0130] When implanted in a patient, the cords 530a, 530b of the
spinal stabilization system 510 can limit the range of flexion of
the spinal segment, whereas the spacers 24 can limit the range of
extension of the spinal segment. For instance, the cords 530a, 530b
can be placed in tension and the spacers 24 can be placed in
compression between the pedicle screws 12.
[0131] The spinal stabilization system 510 can also include inserts
532 configured to be inserted into the channels of the housings 14
of the pedicle screws 12. The insert 532 is further illustrated in
FIGS. 24-26. The inserts 532, which can be considered spools in
some instances, can include a first flange 534 proximate a first
end of the insert 532, a second flange 536 proximate the second end
of the insert 532, and a medial portion 538 intermediate the first
flange 534 and the second flange 536 and extending therebetween.
The insert 532 can have end surfaces 548 configured to abut an end
surface of the spacers 24. For instance, when assembled an end
surface 548 of an insert 532 coupled with the first pedicle screw
12 can abut an end surface of the spacer 24 proximate the first end
of the spacer 24 and an end surface 548 of an insert 532 coupled
with the second pedicle screw 12 can abut an end surface of the
spacer 24 proximate the second end of the spacer 24.
[0132] The insert 532 can be configured such that the medial
portion 538 is positionable in the channel of the housing 14 of the
pedicle screw 12 with the first flange 534 positioned exterior of
the housing 14 and facing the first side of the housing 14 and the
second flange 536 positioned exterior of the housing 14 and facing
the second side of the housing 14.
[0133] The insert 532 can include a plurality of bores extending
therethrough, such as a first bore 540a and a second bore 540b,
each extending from a first end surface 548 at the first end of the
insert 532 to a second end surface 548 at the second end of the
insert 532. As shown in FIG. 26, the first bore 540a can extend
generally parallel to and spaced apart from the second bore 540b.
Each of the bores 540a, 54b can be configured to receive one of the
cords 530a, 530b therein. For instance, the first cord 530a can be
inserted into and/or through the first bore 540a of the insert 532
and the second cord 530b can be inserted into and/or through the
second bore 540b of the insert 532.
[0134] The insert 532 can include an opening 542 in the medial
portion 538 of the insert 532 for receiving a clamping member to
bear against the cords 530a, 530b. As shown in FIG. 25, the opening
542 can intersect with each of the first and second bores 540a,
540b to provide direct engagement of the clamping member with a
portion of each of the first and second cords 530a, 530b positioned
in the bores 540a, 540b, respectively. In some instances, the
insert 532 can include a lower portion 543 of the opening 542
extending below the first and second bores 540a, 540b such that the
opening 542 extends entirely through the insert 532 from an upper
surface to a lower surface of the medial portion 538 to accommodate
the K-wire 590 extending through the opening 542 of the insert 532,
as shown in FIG. 23A. In some instances, the insert 532 can be
positioned in the channel of the housing 14 of the pedicle screw 12
with the first and second cords 530a, 530b extending through the
first and second bores 540a, 540b of the insert 532 by advancing
the insert 532 along the K-wire 590 (i.e., with the K-wire 590
extending through the opening 542) while the K-wire 590 is
positioned through the longitudinal lumen extending through the
shaft 16 of the pedicle screw 12 and the opening 542 through the
insert 532. The K-wire 590 can extend through the opening 542 of
the insert 532 with the K-wire 590 positioned between the first and
second cords 530a, 530b. Thus, the longitudinal lumen extending
through the shaft 16 of the pedicle screw 12 and the opening 542
through the insert 532 can be coaxially aligned, in some
instances.
[0135] The clamping member can be a fastener 520, such as a
threaded set screw including threads which mate with threads formed
in the housing 14. The fastener 520 can be rotatably engaged
between spaced apart legs of the housing 14 to apply a clamping
force to the first and second cords 530a, 530b to clamp or secure
the cords 530a, 530b within the first and second bores 540a, 540b
of the insert 532 while simultaneously clamping the insert 532 in
the housing 14 of a pedicle screw 12. For example, as shown in
FIGS. 23B and 27, the fastener 520 can include a threaded portion
226 and a protuberance 224 extending from the threaded portion 226.
As shown in FIG. 27, the protuberance 224 can extend into the
opening 542 to bear against each of the first and second cords
530a, 530b and simultaneously clamp the first and second cords
530a, 530b in the first and second bores 540a, 540b, respectively.
In some instances, the cords 530a, 530b can be clamped in the
insert 532 with the fastener 520 while the K-wire 590 is positioned
through the longitudinal lumen extending through the shaft 16 of
the pedicle screw 12, the opening 542 through the insert 532, and
the opening 528 through the fastener 520. Thus, the longitudinal
lumen extending through the shaft 16 of the pedicle screw 12, the
opening 542 through the insert 532, and the opening 528 through the
fastener 520 can be coaxially aligned, in some instances.
[0136] Those skilled in the art will recognize that the present
invention may be manifested in a variety of forms other than the
specific embodiments described and contemplated herein.
Accordingly, departure in form and detail may be made without
departing from the scope and spirit of the present invention as
described in the appended claims.
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