U.S. patent application number 17/141595 was filed with the patent office on 2021-04-29 for surgical implant system and method.
This patent application is currently assigned to WARSAW ORTHOPEDIC INC.. The applicant listed for this patent is WARSAW ORTHOPEDIC INC.. Invention is credited to JEREMY J. RAWLINSON, MOLLY K. RICE, JONATHAN SHULTZ.
Application Number | 20210121202 17/141595 |
Document ID | / |
Family ID | 1000005324730 |
Filed Date | 2021-04-29 |
United States Patent
Application |
20210121202 |
Kind Code |
A1 |
RAWLINSON; JEREMY J. ; et
al. |
April 29, 2021 |
SURGICAL IMPLANT SYSTEM AND METHOD
Abstract
A spinal construct comprises a member extending between a first
end and a second end and includes a first layer and a second layer.
The first layer includes a plurality of interlaced strands that
define a first angle. The second layer includes a plurality of
interlaced strands that define a second angle. The first angle is
smaller than the second angle. Systems, implants, surgical
instruments and methods are disclosed.
Inventors: |
RAWLINSON; JEREMY J.;
(MEMPHIS, TN) ; RICE; MOLLY K.; (MEMPHIS, TN)
; SHULTZ; JONATHAN; (COOPERSBURG, PA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
WARSAW ORTHOPEDIC INC. |
WARSAW |
IN |
US |
|
|
Assignee: |
WARSAW ORTHOPEDIC INC.
WARSAW
IN
|
Family ID: |
1000005324730 |
Appl. No.: |
17/141595 |
Filed: |
January 5, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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16401957 |
May 2, 2019 |
10893888 |
|
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17141595 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 17/7022 20130101;
A61B 17/7031 20130101; A61B 17/7029 20130101; A61B 17/7032
20130101 |
International
Class: |
A61B 17/70 20060101
A61B017/70 |
Claims
1-20. (canceled)
21. A method comprising: positioning a tether into cavities of
spaced apart first and second fasteners; and engaging a first set
screw with the first fastener and engaging a second set screw with
the second fastener such that the set screws engage the tether,
wherein the tether extends between a first end and a second end and
includes a first layer and a second layer, the first layer
including a plurality of interlaced strands that define a first
angle, and the second layer including a plurality of interlaced
strands that define a second angle, the first angle being smaller
than the second angle, the tether having the same physical
characteristics along the entire length of the tether.
22. The method recited in claim 21, wherein the set screws engage
the tether such that penetrating elements of the set screws contact
the tether.
23. The method recited in claim 21, wherein the set screws engage
the tether such that penetrating elements of the set screws contact
the tether to separate the first layer from the second layer.
24. The method recited in claim 21, wherein the set screws engage
the tether such that penetrating elements of the set screws contact
the tether to compress the first and second layers.
25. The method recited in claim 21, wherein the set screws engage
the tether such that penetrating elements of the set screws
partially penetrate the tether.
26. The method recited in claim 21, wherein the set screws engage
the tether such that penetrating elements of the set screws
partially penetrate the tether to separate the first layer from the
second layer.
27. The method recited in claim 21, wherein the set screws engage
the tether such that penetrating elements of the set screws
partially penetrate the tether to compress the first and second
layers.
28. The method recited in claim 21, wherein the set screws engage
the tether such that penetrating elements of the set screws crimp
the tether such that the penetrating elements extend completely
through the tether.
29. The method recited in claim 21, wherein the set screws engage
the tether such that penetrating elements of the set screws crimp
the tether such that the penetrating elements extend completely
through the tether and into cannulations of the fasteners.
30. The method recited in claim 21, wherein the set screws engage
the tether such that translation of the tether relative to the
fasteners is prevented.
31. A method comprising: positioning a tether into cavities of
spaced apart first and second fasteners; and engaging a first set
screw with the first fastener and engaging a second set screw with
the second fastener such that the set screws engage the tether,
wherein the tether comprises an inner braid including a plurality
of carriers oriented to define a first angle in a range of 15
through 65 degrees and 1 through 25 picks per inch, the tether
comprising an outer braid including a plurality of carriers
oriented to define a second angle in a range of 35 through 90
degrees and 15 through 35 picks per inch, the tether having the
same physical characteristics along the entire length of the
tether.
32. The method recited in claim 31, wherein the set screws engage
the tether such that penetrating elements of the set screws contact
the tether.
33. The method recited in claim 31, wherein the set screws engage
the tether such that penetrating elements of the set screws contact
the tether to separate the carriers of the inner braid from the
carriers of the outer braid.
34. The method recited in claim 31, wherein the set screws engage
the tether such that penetrating elements of the set screws contact
the tether to compress the carriers of the inner braid and the
carriers of the outer braid.
35. The method recited in claim 31, wherein the set screws engage
the tether such that penetrating elements of the set screws
partially penetrate the tether.
36. The method recited in claim 31, wherein the set screws engage
the tether such that penetrating elements of the set screws crimp
the tether such that the penetrating elements extend completely
through the tether.
37. The method recited in claim 31, wherein the set screws engage
the tether such that penetrating elements of the set screws crimp
the tether such that the penetrating elements extend completely
through the tether and into cannulations of the fasteners.
38. The method recited in claim 31, wherein the set screws engage
the tether such that translation of the tether relative to the
fasteners is prevented.
39. A method comprising: positioning a tether into a cavity of a
bone fastener; and engaging a set screw with the bone fastener such
that the set screw engages the tether, wherein the tether extends
between a first end and a second end and includes a first layer and
a second layer, the first layer including a plurality of interlaced
strands that define a first angle, and the second layer including a
plurality of interlaced strands that define a second angle, the
first angle being smaller than the second angle, the tether having
the same physical characteristics along the entire length of the
tether.
40. The method recited in claim 39, wherein the set screw engages
the tether such that a penetrating element of the set screw
contacts the tether to separate the first layer from the second
layer.
Description
TECHNICAL FIELD
[0001] The present disclosure generally relates to medical devices
for the treatment of musculoskeletal disorders, and more
particularly to a surgical system and method for correction of a
spine disorder.
BACKGROUND
[0002] Spinal pathologies and disorders such as scoliosis and other
curvature abnormalities, kyphosis, degenerative disc disease, disc
herniation, osteoporosis, spondylolisthesis, stenosis, tumor, and
fracture may result from factors including trauma, disease and
degenerative conditions caused by injury and aging. Spinal
disorders typically result in symptoms including deformity, pain,
nerve damage, and partial or complete loss of mobility.
[0003] Non-surgical treatments, such as medication, rehabilitation
and exercise can be effective, however, may fail to relieve the
symptoms associated with these disorders. Surgical treatment of
these spinal disorders includes correction, fusion, fixation,
discectomy, laminectomy and implantable prosthetics. Correction
treatments used for positioning and alignment may employ implants,
such as vertebral rods, bone screws and sub-laminar wire, for
stabilization of a treated section of a spine. This disclosure
describes an improvement over these prior technologies.
SUMMARY
[0004] In one embodiment, a spinal construct is provided. The
spinal construct comprises a member extending between a first end
and a second end and includes a first layer and a second layer. The
first layer includes a plurality of interlaced strands that define
a first angle. The second layer includes a plurality of interlaced
strands that define a second angle. The first angle is smaller than
the second angle. In some embodiments, systems, implants, surgical
instruments and methods are disclosed.
[0005] In one embodiment, a vertebral tether is provided. The
vertebral tether comprises an inner braid including a plurality of
carriers oriented to define a first angle in a range of 15 through
65 degrees and 1 through 25 picks per inch. An outer braid includes
a plurality of carriers oriented to define a second angle in a
range of 35 through 90 degrees and 15 through 35 picks per
inch.
[0006] In one embodiment, the spinal construct comprises an
anterior tether extending between a first end and a second end. The
tether comprises a first layer including a plurality of interlaced
strands that define a first angle and a second layer including a
plurality of interlaced strands that define a second angle. The
first angle is smaller than the second angle. A bone fastener
defines an implant cavity configured for disposal of the tether. A
set screw has a penetrating element extending through at least a
portion of the tether.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The present disclosure will become more readily apparent
from the specific description accompanied by the following
drawings, in which:
[0008] FIG. 1 is a side view of one embodiment of components of a
surgical system in accordance with the principles of the present
disclosure;
[0009] FIG. 2 is a perspective view of one embodiment of components
of a surgical system in accordance with the principles of the
present disclosure;
[0010] FIG. 3 is side view, with parts separated, of the components
shown in FIG. 2;
[0011] FIG. 4 is a side view, in part phantom, of one embodiment of
components of a surgical system in accordance with the principles
of the components of the present disclosure;
[0012] FIG. 5 is a side view, in part phantom, of components of one
embodiment of components of a surgical system in accordance with
the principles of the present disclosure;
[0013] FIG. 6 is a cross section view of components one embodiment
of components of a surgical system in accordance with the
principles of the present disclosure; and
[0014] FIG. 7 is a plan view of one embodiment of components of a
surgical system in accordance with the principles of the present
disclosure disposed with vertebrae.
DETAILED DESCRIPTION
[0015] The exemplary embodiments of a surgical system and related
methods of use are discussed in terms of medical devices for the
treatment of musculoskeletal disorders and more particularly, in
terms of a surgical system and method for correction of a spine
disorder. In some embodiments, the surgical system may be employed
in applications for correction of deformities, such as scoliosis
and kyphosis.
[0016] In some embodiments, the present surgical system includes a
spinal construct having a flexible tether. In some embodiments, the
surgical system includes a spinal construct having an anterior
tether. In some embodiments, the surgical system includes a spinal
construct having a flexible tether to facilitate spinal correction
with growth modulation.
[0017] In some embodiments, the present surgical system is employed
with a method including vertebral body tethering that is utilized
to achieve growth modulation in a young patient with a scoliotic
deformity. In some embodiments, the present surgical system is
employed with a method including the step of applying compression
to vertebral growth plates with a unilateral system on the anterior
spine to decrease the growth on the convexity of the deformed
curve. In some embodiments, the surgical system provides reduction
to facilitate growth on the concave side to catch up and either
limit the progression of the deformity and/or restore neutral
alignment.
[0018] In some embodiments, the present surgical system includes a
tether having various parameters required to achieve a flexible
tether that does not inhibit the natural movement of the spine
while maintaining vertebral compression as a unilateral,
tension-only band. In some embodiments, the tether includes a
textile material, such as, for example, a braided construct with
high-strength and high-stiffness in the loading direction, and
soft, low-friction flexibility in other directions. In some
embodiments, the braided tether is configured to be securely
captured in a vertebral bone screw having a selected set screw
configuration. In some embodiments, the set screw is configured to
provide an appropriate axial grip to resist and/or prevent
translation of the flexible tether relative to the head of the bone
screw.
[0019] In some embodiments, the present surgical system includes a
spinal construct having a flexible tether, such as, for example, a
tension band. In some embodiments, the tether is configured to
achieve a certain extension under a specific load. In some
embodiments, the tether includes a stiffness needed to achieve
growth modulation, high-strength and stiffness in a loaded
direction and soft, low-friction flexibility in other directions.
In some embodiments, the tether is configured to provide a
fusionless system for the treatment of idiopathic scoliosis in
young patients.
[0020] In some embodiments, the present surgical system includes a
spinal construct having a flexible tether. In some embodiments, the
flexible tether includes a tension-only band. In some embodiments,
the tether includes a specific extension under a load. In some
embodiments, the tether is configured to achieve vertebral
compression for growth modulation of growth plates. In some
embodiments, the tether is configured with a high strength and a
low friction.
[0021] In some embodiments, the tether is fabricated with an
ultra-high molecular weight polyethylene (UHMWPE). In some
embodiments, the tether is fabricated with a high modulus
polyethylene (HMPE). In some embodiments, the tether is fabricated
with a dual-layered braid. In some embodiments, the tether is
fabricated with selected braid specifications. In some embodiments,
the tether is fabricated with a low friction configuration.
[0022] In some embodiments, the tether is constructed with an
overall tensile strength. In some embodiments, the tether is
constructed with an increased bulk to facilitate capture of the
tether with a bone screw. In some embodiments, the tether is
configured to maintain a circular configuration for symmetric
flexing under a bending force. In some embodiments, the tether is
configured with a dual braid to improve an axial grip when the
tether is under non-axial compression in a capture mechanism. In
some embodiments, the tether includes a dual layered braid
configured to achieve redundancy in tensile loading.
[0023] In some embodiments, the tether includes a range of picks
per inch. In some embodiments, the tether includes a range of braid
angles. In some embodiments, the tether includes a twist that is
independent for fibers before braiding ends. In some embodiments,
the tether is configured with specific parameters and textiles to
achieve a mechanical function in connection with a spinal
correction treatment. In some embodiments, the tether is configured
to achieve minimal extension under a load. In some embodiments, the
tether is configured with flexibility in non-axial loading with
high stiffness and strength in axial loading. In some embodiments,
the tether is configured as a tension band. In some embodiments,
the tether includes a braid angle. In some embodiments, the braid
angle is configured to measure change in the orientation of the
fibers of the outer braid that cause compression of the inner braid
and align tension. In some embodiments, the inner braid has a
smaller braid angle than the outer braid.
[0024] In some embodiments, the present surgical system is employed
for treatment with a pediatric spine having a selected growth
range, for example, a pediatric spine that grows 2 to 3 millimeters
per level per year. In some embodiments, the present surgical
system includes a tether having a stiffness configured to maintain
axial loading within a selected growth range. In some embodiments,
the tether includes an inner braid layer having 32 strands. In some
embodiments, the tether includes an outer layer having 32 strands.
In some embodiments, the tether includes an inner braid layer
having a bulk that retains a selected circular cross section of the
tether.
[0025] In some embodiments, the present surgical system includes a
tether configured for engagement with a bone screw. In some
embodiments, a portion of the bone screw is configured to penetrate
the tether. In some embodiments, the tether is configured for a low
friction separation to facilitate piercing. In some embodiments,
the tether is configured for bulk compression of round dual-braid
layers. In some embodiments, the tether includes an increased axial
grip. In some embodiments, the tether is configured with a tensile
strength greater than or equal to 1400 N. In some embodiments, a
slip or grip breakage may not constitute failure. In some
embodiments, the tether includes elongation of less than or equal
to 8% at a force application of 200 N.
[0026] In some embodiments, the present surgical system includes a
tether having an outer layer with a carrier having 32 ends, such
as, for example, strands. In some embodiments, the present surgical
system includes a tether having an outer layer with carriers that
cross over each other along the outer layer at approximately 25
picks per inch+/-6 picks. In some embodiments, the outer layer
includes a braid angle of approximately 67 degrees+/-15 degrees. In
some embodiments, the outer layer includes an outer diameter of
3.25 mm+/-0.5 mm.
[0027] In some embodiments, the present surgical system includes a
tether having an inner layer with a carrier having 32 ends, such
as, for example, strands. In some embodiments, the present surgical
system includes a tether having an inner layer with carriers that
cross over each other along the inner layer at approximately 10
picks per inch+/-4 picks. In some embodiments, the inner layer
includes a braid angle of approximately 40 degrees+/-15
degrees.
[0028] In some embodiments, the present surgical system is used
with surgical navigation, such as, for example, fluoroscope or
image guidance. In one embodiment, one or all of the components of
the surgical system are disposable, peel-pack, pre-packed sterile
devices. One or all of the components of the surgical system may be
reusable. The surgical system may be configured as a kit with
multiple sized and configured components.
[0029] In one embodiment, the present disclosure may be employed to
treat spinal disorders such as, for example, degenerative disc
disease, disc herniation, osteoporosis, spondylolisthesis,
stenosis, scoliosis and other curvature abnormalities, kyphosis,
tumor and fractures. In one embodiment, the present disclosure may
be employed with other osteal and bone related applications,
including those associated with diagnostics and therapeutics. In
some embodiments, the disclosed surgical system and methods may be
alternatively employed in a surgical treatment with a patient in a
prone, supine position, lateral and/or employ various surgical
approaches to the spine, including anterior, posterior, posterior
mid-line, direct lateral, postero-lateral, and/or antero-lateral
approaches, and in other body regions. The present disclosure may
also be alternatively employed with procedures for treating the
lumbar, cervical, thoracic, sacral and pelvic regions of a spinal
column. The system and methods of the present disclosure may also
be used on animals, bone models and other non-living substrates,
such as, for example, in training, testing and demonstration.
[0030] The present disclosure may be understood more readily by
reference to the following detailed description of the embodiments
taken in connection with the accompanying drawing figures, which
form a part of this disclosure. It is to be understood that this
application is not limited to the specific devices, methods,
conditions or parameters described and/or shown herein, and that
the terminology used herein is for the purpose of describing
particular embodiments by way of example only and is not intended
to be limiting. Also, in some embodiments, as used in the
specification and including the appended claims, the singular forms
"a," "an," and "the" include the plural, and reference to a
particular numerical value includes at least that particular value,
unless the context clearly dictates otherwise. Ranges may be
expressed herein as from "about" or "approximately" one particular
value and/or to "about" or "approximately" another particular
value. When such a range is expressed, another embodiment includes
from the one particular value and/or to the other particular value.
Similarly, when values are expressed as approximations, by use of
the antecedent "about," it will be understood that the particular
value forms another embodiment. It is also understood that all
spatial references, such as, for example, horizontal, vertical,
top, upper, lower, bottom, left and right, are for illustrative
purposes only and can be varied within the scope of the disclosure.
For example, the references "upper" and "lower" are relative and
used only in the context to the other, and are not necessarily
"superior" and "inferior".
[0031] As used in the specification and including the appended
claims, "treating" or "treatment" of a disease or condition refers
to performing a procedure that may include administering one or
more drugs to a patient (human, normal or otherwise or other
mammal), employing implantable devices, and/or employing
instruments that treat the disease, such as, for example, micro
discectomy instruments used to remove portions bulging or herniated
discs and/or bone spurs, in an effort to alleviate signs or
symptoms of the disease or condition. Alleviation can occur prior
to signs or symptoms of the disease or condition appearing, as well
as after their appearance. Thus, treating or treatment includes
preventing or prevention of disease or undesirable condition (e.g.,
preventing the disease from occurring in a patient, who may be
predisposed to the disease but has not yet been diagnosed as having
it). In addition, treating or treatment does not require complete
alleviation of signs or symptoms, does not require a cure, and
specifically includes procedures that have only a marginal effect
on the patient. Treatment can include inhibiting the disease, e.g.,
arresting its development, or relieving the disease, e.g., causing
regression of the disease. For example, treatment can include
reducing acute or chronic inflammation; alleviating pain and
mitigating and inducing re-growth of new ligament, bone and other
tissues; as an adjunct in surgery; and/or any repair procedure.
Also, as used in the specification and including the appended
claims, the term "tissue" includes soft tissue, ligaments, tendons,
cartilage and/or bone unless specifically referred to
otherwise.
[0032] The following discussion includes a description of a
surgical system and related methods of employing the surgical
system in accordance with the principles of the present disclosure.
Alternate embodiments are also disclosed. Reference is made in
detail to exemplary embodiments of the present disclosure, which
are illustrated in the accompanying figures. Turning to FIGS. 1-6,
there are illustrated components of a surgical system, such as, for
example, a spinal implant system 10.
[0033] The components of spinal implant system 10 can be fabricated
from biologically acceptable materials suitable for medical
applications, including metals, synthetic polymers, ceramics and
bone material and/or their composites. For example, the components
of spinal implant system 10, individually or collectively, can be
fabricated from materials such as stainless steel alloys,
commercially pure titanium, titanium alloys, Grade 5 titanium,
super-elastic titanium alloys, cobalt-chrome alloys, stainless
steel alloys, superelastic metallic alloys (e.g., Nitinol, super
elasto-plastic metals, such as GUM METAL.RTM. manufactured by
Toyota Material Incorporated of Japan), ceramics and composites
thereof such as calcium phosphate (e.g., SKELITE.TM. manufactured
by Biologix Inc.), thermoplastics such as polyaryletherketone
(PAEK) including polyetheretherketone (PEEK), polyetherketoneketone
(PEKK) and polyetherketone (PEK), carbon-PEEK composites,
PEEK-BaSO.sub.4 polymeric rubbers, polyethylene terephthalate
(PET), fabric, silicone, polyurethane, silicone-polyurethane
copolymers, polymeric rubbers, polyolefin rubbers, hydrogels,
semi-rigid and rigid materials, elastomers, rubbers, thermoplastic
elastomers, thermoset elastomers, elastomeric composites, rigid
polymers including polyphenylene, polyimide, polyimide,
polyetherimide, polyethylene, epoxy, bone material including
autograft, allograft, xenograft or transgenic cortical and/or
corticocancellous bone, and tissue growth or differentiation
factors, partially resorbable materials, such as, for example,
composites of metals and calcium-based ceramics, composites of PEEK
and calcium based ceramics, composites of PEEK with resorbable
polymers, totally resorbable materials, such as, for example,
calcium based ceramics such as calcium phosphate such as
hydroxyapatite (HA), corraline HA, biphasic calcium phosphate,
tricalcium phosphate, or fluorapatite, tri-calcium phosphate (TCP),
HA-TCP, calcium sulfate, or other resorbable polymers such as
polyaetide, polyglycolide, polytyrosine carbonate, polycaroplaetohe
and their combinations, biocompatible ceramics, mineralized
collagen, bioactive glasses, porous metals, bone particles, bone
fibers, morselized bone chips, bone morphogenetic proteins (BMP),
such as BMP-2, BMP-4, BMP-7, rhBMP-2, or rhBMP-7, demineralized
bone matrix (DBM), transforming growth factors (TGF, e.g.,
TGF-.beta.), osteoblast cells, growth and differentiation factor
(GDF), insulin-like growth factor 1, platelet-derived growth
factor, fibroblast growth factor, or any combination thereof.
[0034] Various components of spinal implant system 10 may have
material composites, including the above materials, to achieve
various desired characteristics such as strength, rigidity,
elasticity, compliance, biomechanical performance, durability and
radiolucency or imaging preference. The components of spinal
implant system 10, individually or collectively, may also be
fabricated from a heterogeneous material such as a combination of
two or more of the above-described materials. The components of
spinal implant system 10 may be monolithically formed, integrally
connected or include fastening elements and/or instruments, as
described herein.
[0035] Spinal implant system 10 comprises a spinal construct 12
that includes a member, such as, for, example, a tether 20. In some
embodiments, tether 20 is configured for disposal along an anterior
portion of tissue forming a fusionless anterior construct. In some
embodiments, tether 20 is configured with a selected extension
under a load. In some embodiments, tether 20 is configured to
achieve vertebral compression for growth modulation of a vertebral
growth plate. Tether 20 is configured to facilitate vertebral
growth modulation by limiting growth along a convex portion of
vertebrae and allowing growth of a concave portion of vertebrae.
Tether 20 is configured with an increased strength and stiffness in
a loading direction, for example, in tension and decreased and low
friction flexibility in other directions. Tether 20 is configured
for engagement with a bone fastener 150, as described herein.
[0036] Tether 20 includes a flexible longitudinal element that
extends between an end 22 and an end 24. Tether 20 includes a layer
30 and a layer 32. Layer 30 is configured for disposal about layer
32, as shown in FIG. 2. Layer 30 and layer 32 each comprise a
braided cylindrical sleeve that defines an inner cavity. In some
embodiments, layer 32 can include a mesh, textile network, solid or
a non-hollow core. In some embodiments, layers 30, 32 can be
relatively disposed in various orientations, such as, for example,
co-axial, side by side, parallel, offset, intertwined, wrapped
and/or staggered. Layers 30, 32 share a load applied to tether 20.
In some embodiments, layer 32 provides strength and layer 30
provides a lubricious surface area. In some embodiments, layer 30
and/or layer 32 can include a smooth and lubricious surface. In
some embodiments, layer 30 and/or layer 32 can be smooth, less
friable and/or reduce micro-fraying in accordance with the material
examples provided herein. In some embodiments, layer 30 and/or
layer 32 can be manufactured from long-chain molecules of HMPE
stretched along the length of each fiber.
[0037] Layer 30 includes a plurality of carriers 34. Carrier 34 is
comprised of a plurality of ends, such as, for example, strands 36.
Strands 36 are interlaced to form carrier 34. Strands 36 have a
flexible configuration and may be fabricated from materials, such
as, for example, UHMWPE, HMPE, fabric, silicone, polyurethane,
silicone-polyurethane copolymers, polymeric rubbers, polyolefin
rubbers, elastomers, rubbers, thermoplastic elastomers, thermoset
elastomers and elastomeric composites. In some embodiments, carrier
34 includes a number of strands in a range of 1 through 100
strands. In some embodiments, carrier 34 includes 32 strands or
ends. The configuration of carriers 34 and/or strands 36 includes
various parameters to form tether 20.
[0038] For example, carriers 34 are disposed in a braided
configuration, such as, for example, by interweaving carriers 34.
Carriers 34 are braided in a configuration and apply a compressive
force to layer 32 upon tensioning of tether 20, as described
herein. Carrier 34 is interlaced with an adjacent carrier 34a at an
intersection point, such as, for example, a pick 40, as shown in
FIG. 2. In some embodiments, carriers 34 are oriented to define a
number of picks 40 per square inch. Picks 40 define a number of
carrier 34 crossing points per longitudinal inch. In some
embodiments, tether 20 includes a selected number of picks 40 per
square inch, for example, selected from a range of 15 through 35
picks per square inch. In some embodiments, tether 20 includes 25
picks 40 per square inch. In some embodiments, a selected number of
picks 40 per square inch creates a lubricious surface area.
[0039] Carriers 34 are braided to form layer 30 and oriented
relative to a longitudinal axis X1 of tether 20 to define a braid
angle .alpha.. In some embodiments, angle .alpha. is in a range of
35 through 90 degrees. In some embodiments, angle .alpha. is 67
degrees. In some embodiments, angle .alpha. is configured to
measure a change in the orientation of carriers 34 that cause
compression of the layer 32 and align tension.
[0040] Layer 32 includes a plurality of carriers 50. Carrier 50 is
comprised of a plurality of ends, such as, for example, strands 52,
as shown in FIG. 3. Strands 52 are interlaced to form carrier 50.
Strands 52 have a flexible configuration and may be fabricated from
materials, such as, for example, UHMWPE, HMPE, fabric, silicone,
polyurethane, silicone-polyurethane copolymers, polymeric rubbers,
polyolefin rubbers, elastomers, rubbers, thermoplastic elastomers,
thermoset elastomers and elastomeric composites. In some
embodiments, carrier 50 includes a number of strands in a range of
1 through 100 strands. In some embodiments, carrier 34 includes 32
strands or ends. The configuration of carriers 50 and/or strands 52
includes various parameters to form tether 20, as described
herein.
[0041] For example, carriers 50 are disposed in a braided
configuration, such as, for example, by interweaving carriers 50.
Each carrier 50 is interlaced with an adjacent carrier 50a at an
intersection point, such as, for example, a pick 54. In some
embodiments, carriers 50 are oriented to define a number of picks
54 per square inch. Picks 54 define a number of carrier 50 crossing
points per longitudinal inch. In some embodiments, tether 20
includes a selected number of picks 54 per square inch, for
example, selected from a range of 1 through 25 picks per square
inch. In some embodiments, tether 20 includes 10 picks 54 per
square inch.
[0042] Carriers 50 are braided to form layer 32 and oriented
relative to axis X1 to define a braid angle .beta.. In some
embodiments, angle .beta. is in a range of 15 through 65 degrees.
In some embodiments, angle .beta. is 40 degrees. Angle .beta. is
less than angle .alpha.. In some embodiments, angle .beta. is less
than angle .alpha. such that tether 20 achieves a selected
extension under a selected load, and/or provides stiffness to
achieve growth modulation, high-strength and stiffness in a loaded
direction and soft, low-friction flexibility in other directions.
In some embodiments, angle .beta. is equal to or greater than angle
.alpha..
[0043] As an axial load is applied in tension to tether 20,
carriers 34 compress to decrease angle .alpha.. Carriers 34
compress layer 32 causing carriers 50 to compress and decrease
angle .beta. such that layer 30 and layer 32 align in tension.
Layers 30, 32 each include a selected and/or relative braid
configuration having selected parameters, as described herein, such
that tether 20 resists and/or prevents extension beyond a selected
elongation under a selected load. As such, tether 20 includes a
stiffness to achieve growth modulation, high-strength and stiffness
in a loaded direction. Compression of layers 30, 32 under load
causes tether 20 to sustain axial tension over time and resist
and/or prevent creep of tether 20. The axial load is shared between
layers 30, 32 to facilitate sustaining a tension on tether 20
during vertebral growth. In some embodiments, tether 20 is
fabricated such that layers 30, 32 provide a selected tensile
strength of tether 20, for example, the tensile strength of tether
20 being greater than or equal to 1400 N. In some embodiments,
tether 20 includes an elongation at a selected force, for example,
the elongation of tether 20 being 8% at a force of 200 N.
[0044] In some embodiments, the flexibility of tether 20 includes
movement in a lateral or side to side direction and prevents
expanding and/or extension in an axial direction upon tensioning
and attachment with a targeted portion of an anatomy. In some
embodiments, all or only a portion of tether 20 may have a
semi-rigid, rigid or elastic configuration, and/or have elastic
properties, similar to the material examples described above, such
that tether 20 provides a selective amount of expansion and/or
extension in an axial direction. In some embodiments, tether 20 may
be compressible in an axial direction. Tether 20 can include a
plurality of separately attachable or connectable portions or
sections, such as bands or loops, or may be monolithically formed
as a single continuous element.
[0045] Tether 20, layers 30, 32, one or more carriers 34, 52 and/or
one or more strands thereof, can have a uniform thickness/diameter.
In some embodiments, tether 20, layers 30, 32, one or more carriers
34, 52 and/or one or more strands thereof, may have various surface
configurations, such as, for example, smooth and/or surface
configurations to enhance fixation, such as, for example, rough,
arcuate, undulating, porous, semi-porous, dimpled, polished and/or
textured. In some embodiments, the thickness defined by tether 20,
layers 30, 32, one or more carriers 34, 52 and/or one or more
strands thereof, may be uniformly increasing or decreasing, or have
alternate diameter dimensions along its length. In some
embodiments, tether 20, layers 30, 32, one or more carriers 34, 52
and/or one or more strands thereof, may have various cross section
configurations, such as, for example, oval, oblong, triangular,
rectangular, square, polygonal, irregular, uniform, non-uniform,
variable and/or tapered. In some embodiments, the surface of tether
20, layers 30, 32, one or more carriers 34, 52 and/or one or more
strands thereof, may include engaging structures, such as, for
example, barbs, raised elements and/or spikes to facilitate
engagement with tissue of the targeted anatomy.
[0046] In some embodiments, tether 20, layers 30, 32, one or more
carriers 34, 52 and/or one or more strands thereof, may have
various lengths. In some embodiments, tether 20, layer 30 and/or
layer 32 may include a length selected from a range of 600 through
900 mm. In some embodiments, tether 20, layer 30 and/or layer 32
may include a length of 750 mm. In some embodiments, tether 20,
layer 30 and/or layer 32 may be braided, such as a rope, or include
a plurality elongated elements to provide a predetermined force
resistance. In one embodiment, all or only a portion of a tether 20
includes a coating. In some embodiments, the coating may include
polyurethane, silicone-polyurethane copolymers, polymeric rubbers,
polyolefin rubbers, elastomers, rubbers, thermoplastic elastomers,
thermoset elastomers and/or elastomeric composites. In some
embodiments, the coating includes visual indicia, such as, for
example, coloration for identification during selection, a
treatment and/or to facilitate manipulation.
[0047] Bone fastener 150 includes an implant receiver 152 and a
screw shaft 154, as shown in FIGS. 4 and 5. Implant receiver 152
extends along and defines an axis X2. Implant receiver 152 includes
a pair of spaced apart arms 158, 160 that define an implant cavity
162 therebetween configured for disposal of tether 20. Arms 158,
160 each extend parallel to axis X2. In some embodiments, arm 158
and/or arm 160 may be disposed at alternate orientations, relative
to axis X2, such as, for example, transverse, perpendicular and/or
other angular orientations such as acute or obtuse, coaxial and/or
may be offset or staggered. Arms 158, 160 each include an arcuate
outer surface extending between a pair of side surfaces. At least
one of the outer surfaces and the side surfaces of arms 158, 160
have at least one recess or cavity therein configured to receive an
insertion tool, compression instrument and/or instruments for
inserting and tensioning bone fastener 150.
[0048] Cavity 162 is substantially U-shaped. In some embodiments,
all or only a portion of cavity 162 may have alternate cross
section configurations, such as, for example, closed, V-shaped,
W-shaped, oval, oblong triangular, square, polygonal, irregular,
uniform, non-uniform, offset, staggered, and/or tapered. Implant
receiver 152 includes thread forms configured for engagement with a
coupling member, such as, for example, a setscrew 180 to retain
tether 20 within cavity 162, as described herein. In some
embodiments, the inner surface of implant receiver 152 may be
disposed with the coupling member in alternate fixation
configurations, such as, for example, friction fit, pressure fit,
locking protrusion/recess, locking keyway and/or adhesive. In some
embodiments, all or only a portion of the inner surface of implant
receiver 152 may have alternate surface configurations to enhance
engagement with tether 20 and/or setscrew 180, such as, for
example, rough, arcuate, undulating, mesh, porous, semi-porous,
dimpled and/or textured. In some embodiments, implant receiver 152
may include alternate configurations, such as, for example, closed,
open and/or side access.
[0049] Implant receiver 152 includes a surface, such as, for
example, a bearing surface 166. Surface 166 defines a cavity, such
as, for example, a cannulation 168. In some embodiments,
cannulation 168 extends into all or a portion of screw shaft 154.
Cannulation 168 is disposed in communication with cavity 162.
Cannulation 168 is configured for disposal of all or a portion of a
penetrating element 184, as described herein.
[0050] In some embodiments, implant receiver 152 is connectable
with screw shaft 154 to include various configurations, such as,
for example, a posted screw, a pedicle screw, a bolt, a bone screw
for a lateral plate, an interbody screw, a uni-axial screw (UAS), a
fixed angle screw (FAS), a multi-axial screw (MAS), a side loading
screw, a sagittal adjusting screw (SAS), a transverse sagittal
adjusting screw (TSAS), an awl tip (ATS), a dual rod multi-axial
screw (DRMAS), midline lumbar fusion screw and/or a sacral bone
screw.
[0051] Set screw 180 has a plug body 182 with an elongate member
engaging portion, such as, for example, penetrating element 184
extending distally from plug body 182. Plug body 182 includes a
surface 184 that defines a thread form 186. Thread form 186 is
formed circumferentially about plug body 182. Plug body 182
includes a cavity, such as, for example, a socket 188 configured
for engagement with a surgical instrument, such as, for example, a
driver. The driver is configured to apply a driving force to set
screw 180 to engage set screw 180 with implant receiver 152. Set
screw 180 includes a lower bearing surface 190 which bears against
tether 20 positioned between bone fastener 150 and set screw 180.
Penetrating element 184 includes a distal end 192 tapered to
facilitate penetration of penetrating element 184 into tether
20.
[0052] In use, attachment of tether 20 to bone fastener 150 with
set screw 180 includes positioning tether 20 within cavity 162
against or adjacent bearing surface 166. Set screw 180 is aligned
with an opening between arms 158, 160. Distal end 192 of
penetrating element 184 contacts or partially penetrates tether 20
such that tether 20, layers 30, 32, one or more carriers 34, 52
and/or one or more strands thereof, are separated and/or
compressed. Set screw 180 is advanced by its threads into implant
receiver 152 until bearing surface 190 contacts tether 20 and
crimps tether 20 between bearing surface 190 and bearing surface
166, and penetrating element 184 extends completely through tether
20.
[0053] Tether 20 has a reduced cross-sectional area along its
crimped portion between bearing surfaces 190, 166. Penetrating
element 184 is at least partially received in cannulation 168 of
bone fastener 150, allowing complete penetration of tether 20 by
penetrating element 184 in combination with crimping. Penetrating
element 184 and/or bearing surfaces 166, 190 provide a bearing
member against which tether 20 acts as it is tensioned or
compressed with longitudinal forces, as shown by arrows A in FIG.
6. Penetrating element 184 facilitates axial grip of tether 20 such
that translation of tether 20 relative to bone fastener 150 is
resisted and/or prevented by friction generated between tether 20
and bearing surfaces 190, 166 and by the bearing support provided
by penetrating element 184.
[0054] In assembly, operation and use, spinal implant system 10,
similar to the systems and methods described herein, is employed
with a surgical procedure, such as, for example, a correction
treatment of an affected portion of a spine, for example, a
correction treatment to treat adolescent idiopathic scoliosis
and/or Scheuermann's kyphosis of a spine. In some embodiments, one
or all of the components of spinal implant system 10 can be
delivered or implanted as a pre-assembled device or can be
assembled in situ. Spinal implant system 10 may be completely or
partially revised, removed or replaced.
[0055] In use, to treat a selected section of vertebrae V, as shown
in FIG. 7, a medical practitioner obtains access to a surgical site
including vertebrae V in any appropriate manner, such as through
incision and retraction of tissues. In some embodiments, spinal
implant system 10 can be used in any existing surgical method or
technique including open surgery, mini-open surgery, minimally
invasive surgery and percutaneous surgical implantation, whereby
vertebrae V is accessed through a mini-incision, or a sleeve that
provides a protected passageway to the area. Once access to the
surgical site is obtained, the particular surgical procedure can be
performed for treating the spine disorder.
[0056] An incision is made in the body of a patient and a cutting
instrument (not shown) creates a surgical pathway for implantation
of components of spinal implant system 10. A preparation instrument
(not shown) can be employed to prepare tissue surfaces of vertebrae
V as well as for aspiration and irrigation of a surgical region.
Pilot holes (not shown) are made in selected levels of vertebrae V
for receiving one or more bone fasteners 150.
[0057] Tether 20 is disposed along vertebrae V and is positioned
within cavities 162 of bone fasteners 150 against or adjacent
bearing surfaces 166. Set screws 180 are aligned with the openings
between arms 158, 160. For each bone fastener 150, distal end 192
of penetrating element 184 contacts or partially penetrates tether
20 such that tether 20, layers 30, 32, one or more carriers 34, 52
and/or one or more strands thereof are separated and/or compressed.
Set screw 180 is advanced by its threads into implant receiver 152
until bearing surface 190 contacts tether 20 and crimps tether 20
between bearing surface 190 and bearing surface 166, and
penetrating element 184 extends completely through tether 20.
[0058] Penetrating element 184 is at least partially received in
cannulation 168 of bone fastener 150, allowing complete penetration
of tether 20 by penetrating element 184 in combination with
crimping tether 20. Penetrating element 184 facilitates axial grip
of tether 20 such that translation of tether 20 relative to bone
fastener 150 is resisted and/or prevented by friction generated
between tether 20 and bearing surfaces 190, 166 and by the bearing
support provided by penetrating element 184.
[0059] Tether 20 and/or a tension thereof is employed to displace,
pull, twist or align vertebrae V as part of a correction system and
treatment. In some embodiments, tether 20 has a flexible
configuration, which includes movement in a lateral or side to side
direction and resists and/or prevents expanding and/or extension in
an axial direction upon fixation with vertebrae V. Tether 20
includes layer 30 comprising a braided sleeve with layer 32
comprising a braided sleeve disposed within an inner cavity of
layer 30, as described herein.
[0060] For example, during vertebral growth of vertebrae V, an
axial load is applied in tension to tether 20 such that carriers 34
compress to decrease angle .alpha.. Carriers 34 compress layer 32
causing carriers 50 to compress and decrease angle .beta. such that
layer 30 and layer 32 align in tension. Layers 30, 32 each include
a selected and/or relative braid configuration having selected
parameters, as described herein, such that tether 20 resists and/or
prevents extension beyond a selected elongation under a load
applied to tether 20 by vertebrae V during growth, as shown by
arrows B in FIG. 7. As such, tether 20 includes a stiffness to
achieve growth modulation, high-strength and stiffness in a loaded
direction, as shown by arrows B in FIG. 7. The constant tension
along tether 20 facilitates growth modulation by compressing
vertebral growth plates along an anterior portion of vertebrae V.
Growth along a convex CX portion of vertebrae V is decreased
allowing growth of the concave CA portion of vertebrae V.
[0061] Upon completion of the procedure, the surgical instruments,
assemblies and non-implanted components of spinal implant system 10
are removed from the surgical site and the incision is closed. One
or more of the components of spinal implant system 10 can be made
of radiolucent materials such as polymers. Radiomarkers may be
included for identification under x-ray, fluoroscopy, CT or other
imaging techniques. In some embodiments, the use of surgical
navigation, microsurgical and image guided technologies may be
employed to access, view and repair spinal deterioration or damage,
with the aid of spinal implant system 10.
[0062] In some embodiments, spinal implant system 10 includes an
agent, which may be disposed, packed, coated or layered within, on
or about the components and/or surfaces of spinal implant system
10. In some embodiments, the agent may include bone growth
promoting material, such as, for example, bone graft to enhance
fixation of bone fasteners 150 with vertebrae V. In some
embodiments, the agent may include one or a plurality of
therapeutic agents and/or pharmacological agents for release,
including sustained release, to treat, for example, pain,
inflammation and degeneration.
[0063] In some embodiments, the components of spinal implant system
10 may be employed to treat progressive idiopathic scoliosis with
or without sagittal deformity in either infantile or juvenile
patients, including but not limited to prepubescent children,
adolescents with continued growth potential, and/or older children
whose growth spurt is late or who otherwise retain growth
potential. In some embodiments, the components of spinal implant
system 10 may be used to prevent or minimize curve progression in
individuals of various ages.
[0064] It will be understood that various modifications may be made
to the embodiments disclosed herein. Therefore, the above
description should not be construed as limiting, but merely as
exemplification of the various embodiments. Those skilled in the
art will envision other modifications within the scope and spirit
of the claims appended hereto.
* * * * *