Note: Descriptions are shown in the official language in which they were submitted.
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SCREW ASSEMBLY
TECHNICAL FIELD
[0001] This invention relates to medical devices.
BACKGROUND
[0002] The use of spinal stabilization/fixation devices to align or position
specific
vertebra or a region of the spine is well established. Typically such devices
utilize a
spinal fixation element, comprised of a relatively rigid member such as a
plate, board or
rod that is used as a coupler between adj acent vertebrae. Such a spinal
fixation element
can effect a rigid positioning of adjacent vertebrae when attached (e.g. to
the pedicle
portion of the vertebra) using bone anchorage screws (e.g. pedicle screws).
Once the
coupled vertebrae are spatially fixed in position, procedures can be
performed, healing
can proceed or spinal fusion may take place.
[0003] Spinal fixation elements may be introduced posteriorly to stabilize the
various vertebrae of the spine, for example, in conjunction with a kyphoplasty
procedure
wherein a void or cavity is made inside a vertebral body followed by filling
with a bone
substitute to form an "internal cast." Some conventional devices for this
purpose are
designed to be attached directly to the posterior of the spine, but the
generally invasive
nature of a conventional posterior approach used to implant these devices
poses
drawbacks. One minimally invasive solution to the problem of the posterior
approach
involves making a longitudinal separation of the sacrospinalis group between
the
multifudus and longissimus utilizing the natural cleavage plane between these
two
muscles rather than detaching the paraspinal muscles from the posterior spinal
elements.
Problems stemming from the prior art solutions include a high degree of
invasiveness
resulting in muscle disruption and blood loss. The loss of the paraspinal
muscle
attachment sites, formation of scar tissue, and loss of muscle function may
compromise
the patient's final outcome. Additionally, the prior art solutions are time
consuming and
are difficult to remove.
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SUMMARY
[0004] In general, in one aspect, the invention provides a medical device for
supporting a structure comprising a screw assembly The screw assembly includes
a base,
an arm, and an interconnection means for coupling the base to the arm. The
interconnection means allows the arm to be positionable in a first position
that is parallel
to a long axis of the base and positionable in a second position that is
perpendicular to the
long axis of the base. The base is configured for attachment to a structure in
a patient and
the arm configured for attachment to a support structure. In one
implementation, the
structure attached to is bone.
[0005] The device can include a support structure and the screw assembly can
be
attached to the support structure by the arm. Alternatively, two screw
assemblies can be
attached to the support structure.
[0006] The screw assembly can be comprised of a material selected from the
group consisting of titanium, stainless steel, carbon fiber, shape memory
metal, a
biocompatible material and a reabsorbable material and a composite or
combination
thereof. Alternatively, the screw assembly can be comprised of a continuous
piece of
shape memory metal. In one implementation the interconnection means is
comprised of
shape memory metal. In another implementation, the screw assembly, including
the
interconnection means is comprised of a piece of metal suited for bending.
[0007] The screw assembly can be of varying lengths, including an overall
length
in the range substantially between 0.1 and 100 centimeters. In one
implementation, the
overall length is in the range substantially between 50 and 600 millimeters.
In another
implementation, the screw assembly has an overall length sized for
subcutaneous support
of the spine. In yet another implementation, the screw assembly has an overall
length
sized for subcutaneous support of the posterior of a spine.
[0008] The arm of the screw assembly can be comprised of a body, a base yoke
and a connector end. The body of the arm can be any of a number of shapes
including
rod shaped.
[0009] The base of the screw assembly can be comprised of a base head and an
anchor. The anchor can be selected from the group consisting of a screw,
staple, hook or
nail. In one implementation the anchor is a screw configured for bone
anchoring. In
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another implementation, the anchor is a screw configured for insertion into
the pedicle of
a vertebrae.
[0010] The interconnection means of the screw assembly can be of any of a
number of configurations. In one implementation, the interconnection means
includes a
press-fit cross pin. In another implementation the interconnection means is
comprised of
an open saddle head and coupling cross piece. The interconnection means can
also
include a setscrew, wherein the setscrew holds the arm and the base together
as a single
unit. Additionally, the setscrew can be tightened within the interconnection
means to
effect locking of the arm in a position that is substantially perpendicular to
the long axis
of the base. In another implementation, the locking means can also include a
cam that
can function analogously to the setscrew.
[0011] In one implementation, the device can be comprised of one screw
assembly and a support structure, wherein the support structure includes a top
surface, a
bottom surface, an aperture and two receivers. In this implementation, the
aperture can
pass from the top surface through to the bottom surface of the support
structure, wherein
an anchor is disposed within the central aperture in an orientation
substantially
perpendicular to the top surface of the support structure.
[0012] The support structure of the device can be comprised of a top surface,
a
bottom surface and two receivers. Each receiver can include an open-ended
saddle type
receiver configured for attachment of one or more medical devices.
Additionally, each
receiver can include a locking means. The locking means can be a setscrew or
cam. The
locking means can be oriented within the plane of the top surface such that
access to the
locking means is from the top surface. The support structure can be configured
to receive
the medical devices and lock the medical devices to the support structure
after the support
structure has been installed.
[0013] The support structure can be comprised of a material selected from the
group consisting of titanium, stainless steel, carbon fiber, a biocompatible
material, a
reabsorbable material and a composite or combination thereof. Additionally,
the support
structure can include a central aperture passing from the top surface through
to the bottom
surface of the support structure. An anchor can be disposed within the central
aperture in
an orientation substantially perpendicular to the top surface of the support
structure.
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Alternatively, the support structure can include a central hinged claw having
a threaded
hinge-engagement member and nut disposed on the top surface. In use,
tightening the nut
onto the threaded hinge-engagement member causes a pivoting about the hinge to
effect
closing of the claw.
[0014] The device can be comprised of two screw assemblies and a support
structure, wherein each screw assembly includes a base, an arm, and an
interconnection
means for coupling the base to the arm. ,The interconnection means allows the
arm to be
positionable in a first position that is parallel to a long axis of the base
and positionable in
a second position that is perpendicular to the long axis of the base. In this
implementation, the base can be configured for attachment to a structure in a
patient and
the arm configured for attachment to the support structure. In one
implementation, the
structure attached to is bone. Additionally, the support structure can include
a top surface,
a bottom surface and two receivers, wherein each receiver includes an open-
ended saddle
type receiver configured for attachment to a medical device (e.g., screw
assembly). The
support structure can also include a locking means, to lock medical devices to
the support
structure after the support structure has been installed in a patient. The
locking means can
be setscrews or cams. Furthermore, the support structure in this
implementation can
include an anchor configured for attachment to a structure in a patient. In
one
implementation, the structure attached to in a patient is bone. Additionally,
the anchor
can be selected from the group consisting of a screw, staple, hook or a nail.
[0015] A method of use of one aspect of the invention for supporting the
spine,
can include the steps of: 1) delivering to bone, two screw assemblies having
arms, bases
and interconnection means; 2) delivering to the vicinity of bone, a support
structure
having two receivers having locking means for the arms of the screw
assemblies; 3)
deploying the arms of the screw assemblies; and 4) engaging the locking means
of the
receivers to secure the arms of the screw assemblies to the support structure.
[0016] Another method of use of one aspect of the invention for supporting the
spine, can include the steps of 1) delivering to bone, two screw assemblies
having aims,
bases and an interconnection means; 2) delivering to bone, a support structure
having a
central aperture with a locking means and an anchor, and two receivers having
a locking
means for the arms of the screw assemblies; 3) deploying the arms of the screw
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assemblies; and 4) engaging the locking means of the receivers to secure the
arms of the
screw assemblies to the support structure.
[0017] Yet another method of use of one aspect of the invention for supporting
the spine, can include the steps of: 1) delivering to bone, a screw assembly
having an arm,
a base and an interconnection means; 2) delivering to bone, a support
structure having a
central aperture with a locking means and an anchor, and a receiver having a
locking
means for the arm of a screw assembly; 3) deploying the arm of the screw
assembly; and
4) engaging the locking means of the receiver to secure the arm of the screw
assembly to
the support structure.
[0018] In a further implementation, the medical device support structure can
include an anchor, a receiver, and a locking means; wherein the anchor is
configured for
attachment to a structure in a patient. The receiver can include an open end
for
attachment to a medical device (e.g., a screw assembly). The locking means can
be
configured to lock the medical device to the support structure, after the
support structure
has been deployed in a patient. In one implementation, the structure is bone.
The locking
means can be a setscrew or a cam. The anchor can be selected from the group
consisting
of a screw, staple, hook or nail. In another implementation, the receiver can
include a
plurality of receivers for receiving medical devices.
[0019] In general, in another aspect, the invention features a medical device
for
supporting a structure comprising a screw assembly including a base and an
arm. The
arm can be a support configured for receiving one or more anchor assemblies
that include
a means for locking the anchor assemblies to the support. The support includes
a top
portion and a bottom portion, and an interconnection means for coupling the
base to the
support. The interconnection means allows the support to be positionable in a
first
position that is substantially parallel to a long axis of the base and
secondarily
positionable substantially perpendicular to the long axis of the base. The
base and the one
or more anchor assemblies are configured for attachment to a structure in a
patient.
[0020] Implementations of one aspect of the invention can include one or more
of
the flowing features. The structure supported by the device can be bone
selected from the
group including a vertebra, femur, tibia, fibula, humerus, radius, ulna,
calcaneous, and a
pelvis.
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[0021] The screw assembly of the device can have an overall length sized for
subcutaneous support of the posterior of a spine.
[0022] The base of the screw assembly can be comprised of a base head having a
shape and a locking means and an anchor. The base head shape can be an open
saddle-
type head. The locking means of the base can be comprised of a setscrew,
wherein the
setscrew is configured to link the support and the base, and wherein
tightening the
setscrew effects locking of the support in a position relative to a long axis
of the base.
The anchor of the base can be selected from the group including a screw,
staple, nail,
hook and a pin. In one embodiment, the anchor is a screw configured for bone
anchoring.
In another embodiment, the anchor is a screw configured for insertion into the
pedicle of
a vertebra.
[0023] The support of the device can have a shape selected from the group
including a board, plate, elongated cross-section, oval, square, I-beam and a
rod. The
support can include a connector end, one or more apertures, and a receiver.
The
connector end can be configured for interconnection of the support and the
base of the
screw assembly. In one embodiment, the connector end is configured for hinge-
type
interconnection of the support and the base of the screw assembly.
[0024] The one or more apertures of the support can include a first connector
end
proximal aperture having a dimensional configuration to support a range of
movement of
the base in relation to the support. The apertures can further include one or
more second
connector end distal apertures for providing access to the base and the means
for locking
the anchor assembly to the support, when assembled with the support.
[0025] The support can include a support member having a top portion and a
bottom portion, a head assembly, and an interconnection means. In one
embodiment, the
support member can include a receiver, and one or more apertures. The one or
more
apertures include a first aperture wherein an anchor assembly is passable
therethrough
and lockably engagable with the support member, and a second aperture wherein
access is
provided from the top portion of the support member to access the head
assembly.
[0026] The head assembly of the support can include a connector end, an
aperture
having a dimensional configuration supporting a range of movement of the base
in
relation to the support, and a connector end proximal aperture having a
dimensional
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configuration to support a range of movement of the base in relation to the
support. The
head assembly can also include a locking means for securing the head assembly
to the
support member, wherein the head assembly is configured for interconnection
with the
support member.
[0027] In general in another aspect, the invention features a method of
supporting
a bony structure, the method including the steps of 1) delivering to bone a
screw
assembly comprising a support having a receiver, a base, an interconnection
means, and a
locking means; 2) deploying the support substantially perpendicular to the
long axis of
the base; 3) passing through the support and implanting one or more anchor
assemblies
having a base and a locking means into bone; 4) locking the bases within one
or more of
the anchor assemblies; 5) locking one or more of the anchor assemblies within
the support
receiver; and 6) engaging the locking means of the screw assembly to secure
the position
of the support in relation to the base.
[0028] In general in a further aspect, the invention features a method of
supporting a bony structure, the method comprising the steps of: 1) delivering
to bone a
screw assembly including: a support comprising a support member having a
receiver, a
head assembly having a connector end, an interconnection means and a locking
means for
securing the head assembly to the support member; a base; an interconnection
means, and
a locking means for securing the support in a position in relation to the
base; 2) deploying
the support substantially perpendicular to the long axis of the base; 3)
passing through the
support and implanting one or more anchor assemblies having a base and a
locking means
into bone; 4) locking the bases within one or more of the anchor assemblies;
5) locking
one or more of the anchor assemblies within the support receiver; 6) locking
the head
assembly within the support member; and engaging the locking means of the
screw
assembly to secure the position of the support in relation to the base.
[0029] In general, in a further aspect, the invention features a medical
device for
supporting a structure including a screw assembly having a base, one or more
arms, and
an interconnection means for coupling the base to the one or more arms. The
interconnection means allows the one or more arms to be positionable in a
first position
that is substantially parallel to a long axis of the base, and secondarily
positionable
substantially perpendicular to the long axis of the base. The base is
configured for
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attachment to a structure in a patient and the one or more arms are configured
for
attachment to one or more support structures.
[0030] Implementations of one aspect of the invention can include one or more
of
the following features. The structure in a patient can be bone. The screw
assembly can
have an overall length sized for subcutaneous support of the posterior of a
spine. The
base of the screw assembly can include a base head and an anchor.
[0031] The interconnection means of the screw assembly can include the base
head of the screw assembly, and the base head can include a receiver and a
setscrew. In
one implementation, the setscrew secures the base to the one or more arms of
the screw
assembly. In another implementation, tightening the setscrew effects locking
of the one
or more arms in a position in relation to the base of the screw assembly. In
one
implementation, the interconnection means includes the base head of the screw
assembly
and the base head includes a hinge means.
[0032] The one or more arms of the device can include a body, wherein the body
has an elongate shape and includes a connector end for attachment to a support
structure,
and a receiver end for connection to the base head receiver portion of the
interconnection
means. In one implementation, the elongate shape of the arm body can include
an offset
section, wherein the offset section is configured to provide a linear
alignment of the base
and the arm body when the arm is positioned substantially parallel to a long
axis of the
base. In another implementation, the elongate shape of the arm body is a shape
configured for fitted interrelation between two or more arms positioned in a
first position
that is substantially parallel to a long axis of the base. In another
implementation, the
receiver end of the one or more arms and the receiver portion of the base head
include a
hinge means. In another implementation, a means is provided for locking the
arm into a
position substantially perpendicular to the long axis of the base. In one
implementation,
the means provided for locking the arm can include a one-way ratchet, a
setscrew or a
cam.
[0033] Implementations of one aspect of the invention can include one or more
of
the following features. The screw assembly of the device can include two arms
and the
receiver ends of the two arms can be configured for interconnection. In one
implementation, one of the receiver ends of the two arms includes a first
collet-type
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receiver end having a substantially cylindrical recess, and the other receiver
end of the
two arms includes a substantially cylindrical shape for interconnection with
the first
collet-type receiver. In another implementation, one of the receiver ends of
the two arms
can include a first collet-type receiver end having a substantially spherical
recess, and the
other receiver end of the two arms can include a substantially spherical shape
for
interconnection with the first collet-type receiver.
[0034] In one implementation, the invention can include the following feature.
The one or more support structures of the device can include an anchor, an
aperture
configured for attachment of an arm of the screw assembly, and a locking means
configured to lock the arm of the screw assembly to the support structure.
[0035] In another implementation, the invention can include the following
feature.
The interconnection means of the screw assembly can include a hinge, a pin or
a collet.
[0036] In general, in another aspect, the invention features a method of
supporting
the spine, the method comprising the steps of: 1) delivering to bone a screw
assembly
having one or more arms, a base and an interconnections means; 2) delivery to
flanking
bone one or more support structures having an aperture and locking means for
the arms of
the screw assembly; 3) deploying the one or more arms of the screw assembly to
the
flanking support structures; 4) locking the one or more arms of the screw
assembly in a
desired position; and 5) engaging the locking means of the support structure
aperture.
[0037] Aspects of the invention may include one or more of the following
advantageous features. In various implementations of the invention the support
and
screw assembly can be pre-loaded together. As such there is no need to connect
the
support and screw assembly at the surgical site. Use of the invention requires
few user
manipulations. For example, the screw assembly can first be inserted into the
pedicle of a
vertebrae. Next, the support which is connected by an interconnection means to
the screw
assembly can be deployed to a desired position. Subsequently, one or more
anchor
assemblies can be added to the support for attachment to additional vertebrae.
[0038] In various implementations of the invention the offset section of the
arm
body can be configured to provide a low-profile to the screw assembly when the
one or
more arms are positioned substantially parallel to a long axis of the base.
The low profile
is advantageous since it facilitates placement of the screw assembly and arms
of the
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device as a single unit, in a minimally invasive manner, through for example,
a narrow
access channel, port or cannula.
[0039] The details of one or more embodiments of the invention are set forth
in
the accompanying drawings and the description below. Other features, objects,
and
advantages of the invention will be apparent from the description and
drawings, and from
the claims.
DESCRIPTION OF DRAWINGS
[0040] FIG lA is a drawing of a screw assembly showing the screw assembly,
arm and base in a first position.
[0041] FIG 1B is a drawing showing the screw assembly in a second position.
[0042] FIG 1C is a drawing showing the screw assembly including a press-fit
cross pin-type interconnection means.
[0043] FIG 1D is a drawing showing an open saddle-type base head.
[0044] FIG lE is a drawing showing an integrally disposed crosspiece.
[0045] FIG 1F is a drawing showing a press-fit cross pin.
[0046] FIG 2A is a drawing showing a support structure.
[0047] FIG 2B is a drawing showing the support structure including a central
aperture and an anchor.
[0048] FIG ZC is a drawing showing the support structure including a hinged
claw.
[0049] FIG 3A is a drawing showing two screw assemblies connected by a
support structure.
[0050] FIG 3B is a drawing showing two screw assemblies connected by a
support structure implanted into the pedicles of the vertebrae of the spine.
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[0051] FIG 4 is a drawing showing one screw assembly connected to a support
structure having a central aperture and an anchor.
[0052] FIG 5 is a drawing showing one screw assembly connected to a base
having an open saddle-type head.
[0053] FIG 6 is a drawing showing cannulas and a support structure tool used
for
implanting the screw assembly and support structure.
[0054] FIG 7 is a drawing of a screw assembly tool used for manipulating the
screw assembly during implantation of the screw assembly in the spine.
[0055] FIG 8A is a drawing of a support assembly.
[0056] FIGS. 8B-C are drawings of a screw assembly having a base and a
support, illustrating the interconnection between the base and the support
such that the
support is positioned substantially parallel (FIG 8B) or perpendicular (FIG
8C) to a long
axis of the base.
[0057] FIG 8D is a drawing of a support.
[0058] FIG 9A is a drawing of an alternative support assembly
[0059] FIGS. 9B-9E are drawings of a screw assembly.
[0060] FIG l0A is a drawing showing a cutaway view of an anchor assembly
prior to being secured within the support.
[0061] FIG lOB is a drawing showing a cutaway view of an anchor assembly
after being secured within the support.
[0062] FIG 11A-11C are drawings of a screw assembly.
[0063] FIG 11D is a cross-sectional drawing of a screw assembly
[0064] FIG 11E is a drawing of a screw assembly
[0065] FIGS. 12A and 12B are cross-sectional drawings of a screw assembly.
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[0066] FIG 12C is a drawing of a screw assembly showing a spherical-shaped
collet-type connection between two arms and a cross-sectional view of a base.
[0067] FIG 12D is a cross-sectional drawing of a screw assembly showing a
spherical-shaped collet-type connection between two arms.
[0068] FIG 13A is a drawing of a support assembly showing a screw assembly
having one arm and a base attached to a support structure.
[0069] FIG 13B is a drawing of a support assembly showing a screw assembly
having two arms and a base attached to two support structures.
[0070] FIG 14 is a drawing showing a support assembly implanted into the
pedicles of the vertebrae of a spine.
(0071] Like reference symbols in the various drawings indicate like elements.
DETAILED DESCRIPTION
[0072] As shown in FIGS. lA and 1B, a screw assembly 1 is provided comprised
of an arm 2 and a base 3 in a single unit. The screw assembly 1 is elongate
and the arm 2
and base 3 of the screw assembly 1, are coupled by an interconnection means 4.
Additionally, as shown in FIGS. lA and 1B, the interconnection means 4
facilitates
movement between the arm 2 and the base 3, such that the arm 2 is positionable
in a first
position that is parallel to a long axis of the base 3 (shown in FIG lA) and
positionable in
a second position that is perpendicular to the long axis of the base 3 (shown
in FIG 1B).
The base 3 of the screw assembly 1 is configured for attachment to a structure
(e.g., a
bone) and the arm 2 is configured for attachment to a support structure 10
(described in
detail below). In application, one or more screw assemblies 1 are attached to
a support
structure 10 (not shown). Preferably, two screw assemblies 1 are attached to a
single
support structure 10.
[0073] In an alternative screw assembly 1 implementation, the arm 2 and base 3
of the screw assembly 1 are configured as one continuous piece of shape memory
metal.
In this implementation, the interconnection means 4 is comprised of a shape
memory
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metal that can facilitate movement of the arm 2 relative to the base 3
depending on preset
conditions affecting the shape memory metal shape (not shown). In another
alternative
screw assembly 1 implementation, the arm 2 and base 3 of the screw assembly 1
are
configured as one continuous piece wherein the interconnection means 4 between
the arm
2 and base 3 is comprised of a material suited for bending (not shown).
[0074] As shown in FIG lA, in certain embodiments, the arm 2 feature of the
screw assembly 1 is comprised of a body 17, base yoke 18 and a connector end
12. The
body 17 of the arm 2 can vary in shape and length with the application. In one
implementation, the body 17 of the arm 2 is rod-shaped (see FIGS. lA and 1B).
Alternatively, the arm 2 body 17 is shaped to substantially fit within a screw
assembly
tool for manipulating the screw assembly 1. An example of such a screw
assembly tool
19 is illustrated in FIG 7.
[0075] The screw assembly 1 can be made of numerous materials that are durable
and that can be implanted in a body, including titanium, stainless steel,
carbon fiber,
biocompatible material, etc. In one implementation, the screw assembly 1 is
made of
titanium. Additionally, the screw assembly 1 can be made of a reabsorbable
material or
shape memory metal. Alternatively, the screw assembly 1 can be a composite or
combination of any of the foregoing. The dimensions of the screw assembly 1
vary with
the application. In general, the length of the screw assembly 1 is from 0.1 to
100
centimeters. In one implementation, the length is substantially between 50 and
600
millimeters. In another implementation, the screw assembly 1 is sized for
applications
involving support of the posterior of the spine 28 (see FIG 3B).
[0076] As shown in FIG lA, the base 2 of the screw assembly 1 is comprised of
a
base head 20 and an anchor 14. The anchor 14 can be a screw, staple, hook or
nail and
can be of a type typically used for bone anchoring. In one implementation the
anchor 14
is a screw of a type for insertion into a pedicle 26 of a vertebrae 27 (see
FIG lA and 3B).
[0077] As shown in FIG. 1 C, the interconnection means 4 of the screw assembly
1 of FIG. lA can be a press-fit cross pin type. In this implementation, the
base head 20 is
a press-fit cross pin-type head 5, and the yoke 18 of the arm 2 includes a pin
hole 25,
wherein the arm 2 and base 3 are pre-assembled including a press-fit cross pin
(not
shown) and a setscrew 9 (not shown). In an alternative implementation, as
shown in
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FIGS. 1D-F, the interconnection means 4 of FIG. lAis configured as an open
saddle head
with coupling-cross piece. In this implementation, the base head 20 is
configured as an
open saddle-type head 6 (shown in FIG. 1D), which is pre-assembled with a
complementary arm 2 feature. As shown in FIG. lE, the arm 2 feature that is
complementary to the open saddle-type head 6 can be a one-piece integrally
disposed
crosspiece 7. Alternatively, as shown in FIG 1F, the complementary arm 2
feature can be
a press-fit cross pin 8.
[0078] As shown in FIGS. lA and 1B, the arm 2 and base 3 can be held together
as a single unit by the set screw 9 where the interconnection means 4 is of
the form of a
press-fit cross pin-type or an open saddle-type head with a coupling cross
piece. In
certain implementations, the open saddle-type head is threaded to receive the
setscrew 9.
[0079] Additionally, as shown in FIGS. lA and 1B, the setscrew 9 can effect
locking of the arm 2 into a fixed position. Prior to moving the arm 2 into the
deployed
position, the setscrew 9 is loosely set in place. TJpon deployment, the arm 2
can be
locked in a position that is substantially perpendicular to the long axis of
the base 3 by
tightening the setscrew 9 into the threaded open saddle head 6 of the base 3
(see FIG 1D).
[0080] In one implementation, locking of the arm 2 position and holding the
arm
2 and base 3 together as a single unit can be achieved using a cam rather than
a setscrew 9
(not shown). Where a cam is substituted for a setscrew 9, locking of the arm 2
and
joining of the arm 2 and the base 3 is achieved by an analogous means.
[0081] Referring now to FIGS. 2A-C, 3A, 3B and 4, a support structure 10 is
shown to which the connector end 12 of the arm 2 of the screw assembly 1 can
be
attached (see FIGS. 3A, 3B and 4). As shown in FIG. 2A, the support structure
10 is
comprised of a top surface 15, a bottom surface 16, and one or more open-ended
saddle
receivers 11 including a setscrew 9, or, in the alternative, a cam, for
locking. The
receiver 11 is shaped to accommodate the connector end 12 of the arm 2 of the
screw
assembly 1. As shown in FIGS. 2A and 2B, the setscrew 9 is threaded into the
support
structure 10, perpendicular to the plane of the top surface 15 of the support
structure 10,
to facilitate access to the setscrew 9 from above the support structure 10. In
one
implementation, the support structure 10 is comprised of two receivers 11 (see
FIGS. 2A-
C, 3A, 3B and 4), whereby two screw assemblies 1 can be linked together via
the support
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structure 10 (see FIG. 3A). In another implementation, as shown in FIG. 3B,
two screw
assemblies 1 linked together via the support structure 10 can be implanted
into the
pedicles 26 of vertebrae 27 in a spine 28 to effect support of the spine 28.
[0082] As shown in FIGS. 2B and 4, the support structure 10 can be configured
to
additionally include a central aperture 13 that passes from the top surface 15
of the
support structure 10 through to the bottom surface 16 of the support structure
10. As
shown in FIGS. 2B and 4, the central aperture 13 can be threaded accommodate
an
anchor 14 and optionally include a setscrew 9 or a cam for locking the anchor
14 in
position. In this implementation the threading of the central aperture 13, and
receiver 11
setscrew(s) 9, are both aligned perpendicularly to the top surface 15 of the
support
structure 10. The anchor 14 can be a screw, staple, hook or nail and be of a
type typically
used for bone anchoring. In one implementation, the anchor 14 is a screw of a
type for
insertion into the pedicle of a vertebrae.
[0083] In another implementation, as shown in FIG. 2C, the support structure
10
can optionally include a hinged claw 21 for clamping the support structure 10
onto a
surface (e.g., a bony surface). The claw 21 features a hinge 22 positioned
between two
receivers 11 in the support structure 10. The claw 21 includes a threaded
engagement
member 23 extending above the top surface 15 of the support structure 10,
whereby upon
threading a nut (not shown) over the engagement member 23, a pivoting about
the hinge
22 is effected and the claw 21 closes.
[0084] The support structure 10 can be made of numerous materials that are
durable and that can be implanted within a body, including titanium, stainless
steel,
carbon fiber, biocompatible material, etc. Preferably, the screw assembly 1 is
made of
titanium. Additionally, the support structure 10 can be made of a reabsorbable
material.
Alternatively, the support structure 10 can be a composite or combination of
any of the
foregoing.
[0085] As shown in FIG 5, another implementation of the invention includes a
single screw assembly 1, connected to a support structure 10 having a receiver
11, an
anchor 14 and a locking means. In one implementation the receiver 11 is
configured as
an open saddle-type head 6. In another implementation, the support structure
10 includes
a plurality of receivers 11. The locking means can include a setscrew 9 or
alternatively a
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cam. In one implementation, the connector end 12 of the screw assembly arm 2
is locked
into the open saddle-type receiver head 6 of the support structure 10 after
the anchor is
installed in a patient.
[0086] As shown in FIG. 6, a method of using the invention to support the
spine
28 includes the steps of 1) making a series of small incisions along the spine
28 to
provide cannula 29 access to the pedicle 26 portions of a series of vertebrae
27; 2) using
the cannula 29 access route, deliver two un-deployed screw assemblies 1 to a
series of
pedicles 26 and screw them into respective pedicles 26 (wherein un-deployed
refers to a
configuration of the screw assemblies such that each arm is set in a position
that is
parallel to the long axis of the base); 3) using the cannula 29 access route
and a support
structure tool 30, deliver, screw into place and lock a support structure 10
having a central
aperture, set screw, two receivers with setscrews and pedicle screw-type
anchor; 4)
deploy the arms of each screw assembly 1 substantially perpendicular to the
long axis of
the base; 5), and engage and lock into place each connector end of each arm
within the
support structure 10 receivers using the set screws.
[0087] The above method includes the use of a special screw assembly tool 19
for
manipulation of the screw assemblies 1 (see FIG. 7). The screw assembly tool
19
includes an inner cavity 24 configured to accommodate the un-deployed screw
assembly
within it. In use, the screw assembly tool 19 facilitates the insertion of the
un-deployed
screw assembly base into a structure (e.g., bone) from within the confines of
a cannula 29
(see FIG. 6).
[0088] An additional method of use of the invention for supporting the spine,
can
include the steps of 1) delivering to bone, two screw assemblies having arms,
bases and
interconnection means; 2) delivering to the vicinity of bone, a support
structure having
two receivers having locking means for the arms of the screw assemblies; 3)
deploying
the arms of the screw assemblies; and 4) engaging the locking means of the
receivers to
secure the arms of the screw assembly to the support structure.
[0089] Another method of use of the invention for supporting the spine, can
include the steps of 1) delivering to bone, two screw assemblies having arms,
bases and
an interconnection means; 2) delivering to bone, a support structure having a
central
aperture with a locking means and an anchor, and two receivers having locking
means for
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the arms of the screw assemblies; 3) deploying the arms of the screw
assemblies; and 4)
engaging the locking means of the receivers to secure the arms of the screw
assemblies to
the support structure.
[0090] Yet another method of use of the invention for supporting the spine,
can
include the steps of: 1) delivering to bone, a screw assembly having an arm,
base and
interconnection means; 2) delivering to bone, a support structure having a
central aperture
with a locking means and an anchor, and a receiver having locking means for
the arm of a
screw assembly; 3) deploying the arm of the screw assembly; and 4) engaging
the locking
means of the receiver to secure the arm of the screw assembly to the support
structure.
[0091] As shown in FIGS. 8A and 9A, a screw assembly 101 is provided
comprising a base 102, a support 103 configured for receiving one or more
anchor
assemblies 301 and an interconnection means 105 between the base 102 and the
support
103. As shown in FIGS. 8A, 8C, 8D and 9A-9E, the support 103 includes a top
portion
107 and a bottom portion 108 (see FIGS. 8B, 8C, 9D and 9E). The
interconnection
means 105 allows the support 103 to be positionable in a first position that
is substantially
parallel to a long axis of the base 102 (see FIGS. 8B, 9B-9D) and secondarily
deployed or
positioned substantially perpendicular to the long axis of the base 102 (see
FIGS. 8A, 8C,
9A and 9E). The base 102 of the screw assembly 101 and the one or more anchor
assemblies 301 are configured for attachment to a structure (e.g. bone) in a
patient. In
application, a screw assembly 101 receives one or more anchor assemblies 301
to form a
support assembly 106 (see FIGS. 8A and 9A). In one implementation, the anchor
assembly 301 is combined with the screw assembly 101 after deployment of the
support
103 (forming support assembly 106) and in another implementation, the anchor
assembly
301 is pre-assembled with the screw assembly 101. One advantage of the
invention over
the prior art solutions is timesavings when using the support assembly 106 for
supporting
a structure. Another advantage is relative ease of removal. The support
assembly 106 can
be used for temporary or permanent implantation.
[0092] . The support assembly 106, once assembled, can be used to support a
bony
structure. The bony structure supported can include a femur or other bones of
the leg
(e.g. tibia and fibula), bones of the arm and wrist (e.g. humerus, radius and
ulna), and
other bones such as the calcareous, pelvis, spine (vertebrae) and the like.
Support can be
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provided for a single bone (i.e. a long bone such as the femur, tibia,
humerus) or for more
than one bone (i.e. vertebrae).
[0093] The screw assembly 101 can be made of materials that are durable and
that
can be implanted in a body, including titanium, stainless steel, carbon fiber,
etc. In one
implementation, the screw assembly 101 is made of titanium. In another
implementation
the screw assembly 101 is made of a biocompatible material, a reabsorbable
material or a
combination of any of the foregoing materials. The dimensions of the screw
assembly
101 vary with the application. In general, the length of the screw assembly 1
O l is from
20 to 1,000 millimeters. In one implementation, the length is substantially
between 50
and 400 millimeters. In another implementation, the screw assembly 101 is
sized for
applications involving support of the posterior of the spine (not shown).
[0094] As shown in FIGS. 8A-8C, 9A-9E and l0A-lOB, the base 102 of the screw
assembly 101 is comprised of a base head 114 having a shape and a locking
means, and
an anchor 109a. The shape of the base head 114 can be comprised of any of a
number of
shapes suitable for receiving or interconnecting with the support 103. In one
implementation, the base head 114 shape is an open saddle-type head. As shown
in
FIGS. 8A, 8C and 9A, in one implementation, the locking means of the base head
114 can
be a setscrew 104. The setscrew 104 can be configured to link the support 103
and the
base 102 while permitting a freedom of movement between the base 102 and the
support
103 (see FIGS. 8A, 9A and 9E). The locking means can effect locking of the
support 103
in a position relative to the base 102. In one implementation the setscrew 104
can be
tightened to effect locking of the support 103 in a position relative to (for
example, the
long axis of) the base 102. In an alternative implementation, the locking
means of the
base head 114 can be a cam (not shown).
[0095] As shown in FIGS. 8A-8C, 9A-9E and l0A-lOB, the anchor 109a of the
screw assembly 101 is can be selected from the group consisting of a screw,
staple, nail,
hook and pin. In one implementation, the anchor 109a is configured for bone
anchoring.
In another implementation, the anchor 109a is a screw configured for insertion
into the
pedicle of a vertebra.
[0096] As shown in FIGS. 8A, 9A and l0A-lOB, the anchor assembly 301 is
configured to interconnect with the shape of the receiver 306 (discussed in
detail below).
1s
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The anchor assembly 301 shape can be any of a number of shapes. In some
implementations, the mating between the support 103 and the anchor assembly
301
occurs only in two dimensions (e.g. where a 90 degree twisting receiver 306 is
employed). As shown in FIGS. l0A-lOB, the anchor assembly 301 can be comprised
of a
head 302, a base 109b and a base head 114. The anchor assembly 301 can be
comprised
of numerous materials that are durable and that can be implanted in a body,
including
titanium, stainless steel, carbon fiber, etc. Additionally, the anchor
assembly 301 can be
comprised of a reabsorbable material or a biocompatible material, or a
combination of
any of the foregoing materials.
[0097] As shown in FIGS. l0A -lOB, the anchor assembly 301 includes a means
for locking the anchor assembly 301 to the support 103. In one implementation,
as shown
in FIG. 10A, where the receiver 306 and complimentary head 302 of the anchor
assembly
301 are T-slot shaped, the means for locking the anchor assembly 301 can be a
setscrew
104 threaded into the head 302 of the anchor assembly 301, wherein the head
302
includes a threaded base aperture 305 and a deformable geometry. Such a means
for
locking an anchor assembly 301 to the support 103 is disclosed in the commonly
owned
U.S. Application Serial No. 11/019,918. As shown in FIG. lOB, when the
setscrew 104 is
turned into the threaded base aperture 305, the deformable head 303 is caused
to splay
outward such that the T-slot shape of the head 302 engages and locks against
the receiver
306 planar medial face 308. As shown in FIGS. l0A and lOB, the setscrew 104
can be
disposed such that it is constrained within the threaded base aperture 305.
The
constrained setscrew 104 upon final tightening can be over-constrained thereby
forcing
the deformable head 303 to splay outward. In another implementation, the head
302 may
additionally engage the receiver 306 planar upper face 309 or planar lower
face 307 or
both to effect locking. In another implementation, a cam can be substituted
for the
setscrew 104 to effect the locking of the anchor assembly 301 within the
support 103 (not
shown).
[0098] The deformable geometry of the deformable threaded base aperture 305
can be comprised of a void within the anchor assembly 301 head 302 wherein the
void is
selected from the list consisting of a cavity, slot notch, groove, cut out,
gap and a recess.
In one implementation, the void is tapered. In another implementation as shown
in FIGS.
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9A and 9A, the void within the anchor assembly 301 head 302, can be a slot 313
cut into
the head 302.
[0099] Other means for locking an anchor assembly 301 to the support 103 are
possible, including those disclosed in U.S. Application Serial No. 10/826,684,
filed April
16, 2004, entitled "Subcutaneous Support".
[00100] As shown in FIGS. 10A-lOB, the anchor assembly 301 includes a base 102
moveably disposed within the threaded base aperture 305. The base 102 can be a
screw,
staple, hook or nail and of a type typically used for anchoring to a structure
(e.g., to a
bone). In one implementation, the base 102 is a screw of a type for insertion
into the
pedicle of a vertebra. In another implementation, the base 102 can be attached
to another
bony structure.
[00101] Attachment of the base 102 to the anchor assembly 301 can be
accomplished in numerous ways. In one implementation, the attachment is
through a
hinge-type of connection between the base 102 and the anchor assembly 301
(see, e.g., as
in FIGS. lA-1B). In another implementation, as shown in FIGS. l0A-lOB, the
attachment is made between a polyaxial-type base head 114 on the base 102 and
a
complimentary receptacle 304 within the anchor assembly 301 head 302.
[00102] The anchor assembly 301 further includes a means for locking the base
102 within the anchor assembly 301 head 302. As shown in FIGS. l0A-lOB, for a
polyaxial-type base head 114, the means for locking can include a setscrew 104
disposed
within a threaded base aperture 305. In this configuration, turning the
setscrew 104
causes the setscrew 104 to press directly against the polyaxial base head 114
of the base
102, thereby forcing it against the receptacle 304 of the anchor assembly 301
to effect
locking. Alternatively, where the base 102 is of the hinge-type, the means for
locking can
be comprised of a setscrew 104 disposed in a threaded base aperture 305. In
this
configuration, turning the setscrew 104 causes the setscrew 104 to press
directly against
the base head 114 of the hinge-type base 102, thereby creating friction
against the hinge's
pin to effect locking (not shown). In another implementation, a cam can be
substituted
for the setscrew 104 to effect locking.
[00103] As shown in FIGS. l0A-l OB, another implementation of the anchor
assembly 301 includes a longitudinal aperture 312 through the base 102 and
base head
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114, a tool interface 311 and a setscrew aperture 310. The longitudinal
aperture 312 and
setscrew aperture 310 are configured such that an instrument, wire (e.g. a K-
wire) or
other guide can pass through the entire anchor assembly 301. The setscrew
aperture 310
is further configured such that a tool or instrument can pass through the
setscrew aperture
310 to engage the tool interface 311 of the base 102. Alternatively, the
setscrew 104 can
be a cam (not shown).
[00104] The setscrew aperture 310 can be any shape and can be sized to
accommodate the through passage and use of objects and tools without affecting
the
positioning of the setscrew 104.
[00105] The longitudinal aperture 312 can have any desired cross-sectional
shape
including but not limited to round, square, hexagonal, oval or any regular or
irregular
shape.
[00106] The tool interface 311 can be any shape suitable for receiving a tool
for
manipulating the base 102. For example, where the base 102 is a screw, the
tool interface
311 can be a hex shape, or any other commonly used screw head tool interface
shape.
[00107] Where an anchor assembly 301 is configured as shown in FIGS. 10A-lOB,
the setscrew 104 can be pre-positioned within the base aperture 305 without
being
tightened. The setscrew aperture 310 and longitudinal aperture 312 (passing
through the
base 102 and base head 114) enable access through a pre-assembled
implementation of
the anchor assembly 301. Additionally, wherein the anchor assembly 301 is pre-
assembled, access is provided to the tool interface 311 of the base head 114
through the
setscrew aperture 310.
[00108] As shown in FIGS. 8A, 8D, 9A, 9D and 9E, the support 103 has a shape.
The shape of the support 103 can be selected from the group consisting of a
board, plate,
elongated cross-section, oval, square, I-beam and a rod. In one
implementation, as shown
in FIGS. 8A, 8D, 9A, 9D and 9E, the support is shaped as a plate. In one
implementation,
the length of the support 103 is minimally substantially the same length as
required to
span two or more vertebrae. In one implementation, the support 103 is
substantially a
length as required to span three vertebrae. In another implementation, the
length of the
support 103 is substantially between 25 to 140 millimeters.
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[00109] As shown in FIGS. 8A-8D, in one implementation the support 103 is
comprised of a connector end 110, one or more apertures 111, and a receiver
306. The
connector end 110 is configured for interconnection of the support 103 and the
base 102
of the screw assembly 101. In one implementation, the connector end 110 is
configured
for hinge-type interconnection of the support 103 and the base102 of the screw
assembly
101.
[00110] As shown in FIGS. 8A, 8B, and 8D, in one implementation the one or
more apertures 111, of the support 103 include a first aperture 111 c
positioned proximal
to the connector end 110, and a second aperture 111 a positioned distal to the
connector
end 110, in relation to the support 103. As shown in FIGS. 8A, 8B and 8D, the
first
aperture 111 c, can provide for a range of movement for the base 102 in
relation to the
support 103. In one implementation, the movement of the base 102 in relation
to the
support 103 includes a hinge-type of movement (see FIGS. 8A-8C). As shown in
FIG
8A, the second aperture 111a can provide for access to the base 103 and the
means for
locking the anchor assembly 301 to the support 103, when the anchor assembly
301 is
assembled with the support 103. In one implementation, the second aperture 111
a can
provide for access to the support 103 from above after the support 103 is
deployed into a
position that is substantially perpendicular to the base 102.
[00111] As shown in FIGS. 8A and 8D, in one implementation, the receiver 306
is
disposed within a long axis of the support 103. In another implementation, the
receiver
306 is connected to the top portion 107 or the bottom portion 108 of the
support 103. In
an additional implementation, the receiver 306 substantially spans the length
of the
support 103. The configuration of the receiver 306 can be comprised of any of
a number
of designs and shapes. In one implementation, the receiver 306 has a
configuration
selected from the group consisting of a slot, groove, track, dovetail and a
snap-in
configuration. In another implementation, the receiver 306 has a 90-degree
twist-in
configuration. In yet another implementation, the receiver 306 and the anchor
assembly
301 are both configured in an interconnecting geometry comprising a T slot
(see FIGS.
l0A and l OB). As shown in FIGS. l0A and l OB, in one implementation, the T
slot
configuration of the receiver 306 can be comprised of a planar upper face 309,
a planar
lower face 307 and a planar medial face 308. The receiver 306 can include two
ends
wherein one or both ends are open or closed (not shown).
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[00112] As shown in FIGS. 9A-9E, in one implementation the support 103 is
comprised of a support member 202, a head assembly 201 and an interconnection
means
105 (for example, a slot-flange combination). The support member 202 can
include a top
portion 107 and a bottom portion 108 and one or more apertures 111 (see FIGS.
9A-9E).
As shown in FIGS. 9A-9C, in one implementation the support member 202 includes
a
receiver 306 and one or more apertures 111.
[00113] As shown in FIG 9A, in one implementation, the receiver 306 is
disposed
within a long axis of the support member 202. In another implementation, the
receiver
306 is connected to the top portion 107 or the bottom portion 108 of the
support member
202 (for example, as an attachment). In an additional implementation, the
receiver 306
substantially spans the length of the support member 202. The configuration of
the
receiver 306 can be comprised of any of a number of designs and shapes. In one
implementation, the receiver 306 has a configuration selected from the group
consisting
of a slot, groove, track, dovetail and a snap-in configuration. In another
implementation,
the receiver 306 has a 90-degree twist-in configuration. In yet another
implementation,
the receiver 306 and the head assembly 201 are both configured in an
interconnecting
geometry comprising a T slot (see FIGS. l0A and l OB). As shown in FIGS. l0A
and
lOB, in one implementation, the T slot configuration of the receiver 306 can
be comprised
of a planar upper face 309, a planar lower face 307 and a planar medial face
308.
[00114] The receiver 306 can include two ends wherein a first end is open and
second end is closed (not shown). Alternatively, both ends can be open or both
ends can
be closed (not shown).
[00115] As shown in FIGS. 9A-9C, in one implementation the one or more
apertures 111, of the support member 202 include a first aperture 111 a
wherein an anchor
assembly 301 is passable therethrough and lockably engagable with the support
member
202. A second aperture l l lb can be included wherein access is provided from
the top
portion 107 of the support member 202, through to the bottom portion 108 of
the support
member 202 (see FIGS. 9A- 9C). As shown in FIGS. 9B and 9C, the second
aperture
l l lb can also provide access to the head assembly 201 of the support 103
when the head
assembly 201 is interconnected with the support member 202.
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[00116] As shown in FIGS. 9A- 9C, in one implementation the head assembly 201
is configured for interconnection with both the support member 202 and the
base 102.
The head assembly 201 includes a connector end 110, an aperture l l lc and a
locking
means (for example, a flange) for securing the head assembly 201 to the
support member
202. In one implementation the receiver 306 of the support member 202 and the
head
assembly 201 are configured in an interconnecting geometry comprising a T
slot. The
interconnecting geometry between the head assembly 201 and the support member
202
can provide for adjustable positioning (and/or locking) of the support member
202 along
the long axis of the head assembly 201 (see FIGS. 9B and 9C). As shown in FIG
9B, the
head assembly 201 can be contracted within the support member 202 to reduce
the overall
length of the screw assembly 101. In contrast, as shown in FIG 9C, the head
assembly
201 can be extended in relation to the support member 202 to increase the
overall length
of the screw assembly 101.
[00117] The connector end 110 of the head assembly 201 can be configured for
interconnection of the support 103 and the base 102 of the screw assembly 101.
In one
implementation, the connector end 110 is configured for hinge-type
interconnection of the
support 103 and the base 102 of the screw assembly 101 (see FIGS. 9A-9E).
[00118] As shown in FIGS. 9A- 9C, the aperture l l lc of the head assembly can
have a dimensional configuration to support a range of movement of the base
102 in
relation to the support 103. Also as shown in FIGS. 9A- 9C, the locking means
for
securing the head assembly 201 to the support member 202 can be comprised of a
setscrew 104 disposed within the head assembly 201. In use, turning the
setscrew 104
can result in contact between the setscrew 104 and the support member 202,
thereby
providing a means to secure the head assembly 201 to the support member 202.
Alternatively, in another implementation, the locking means for securing the
head
assembly 201 to the support member 202 can be comprised of a cam.
[00119] A method of use of the invention for supporting a bony structure, can
include the steps of 1) delivering to bone a screw assembly comprising a
support having
a receiver, a base, an interconnection means, and a locking means; 2)
deploying the
support substantially perpendicular to the long axis of the base; 3) passing
through the
support and implanting one or more anchor assemblies having a base and a
locking means
into bone; 4) locking the bases within one or more of the anchor assemblies;
5) locking
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one or more of the anchor assemblies within the support receiver; and 6)
engaging the
locking means of the screw assembly to secure the position of the support in
relation to
the base.
[00120] In a further implementation, the method of use described above can
include disposing the support adjacent to bone or adjacent to a spine. In one
implementation, the method of use described above can include disposing the
support
with the subcutaneous fat layer of the back. In another implementation, the
method of
use described above can include disposing the support external to the body.
[00121] Another method of use of the invention for supporting a bony
structure,
can include the steps of: 1) delivering to bone a screw assembly comprising: a
support
comprising a support member having a receiver, a head assembly having a
connector end
and an interconnection means; a base; an interconnection means, and a locking
means; 2)
deploying the support substantially perpendicular to the long axis of the
base; 3) passing
through the support and implanting one or more anchor assemblies having a base
and a
locking means into bone; 4) locking the bases within one or more of the anchor
assemblies; 5) locking one or more of the anchor assemblies within the support
receiver;
6) locking the head assembly within the support member; and 7) engaging the
locking
means of the screw assembly to secure the position of the support in relation
to the base.
[00122] In one implementation, the method of use described above can include
disposing the support adjacent to bone or adjacent to a spine. In one
implementation, the
method of use described above can include disposing the support with the
subcutaneous
fat layer of the back. In another implementation, the method of use described
above can
include disposing the support external to the body.
[00123] A method of use of the invention for effecting a desired vertebral
disk
spacing, can include the steps of: 1) implanting a screw assembly comprising a
support
having a receiver, a base, an interconnection means, and a locking means into
a vertebra;
2) deploying the support substantially perpendicular to the long axis of the
base; 3)
passing through the support and implanting one or more anchor assemblies
having a base
and a locking means into a vertebra; 4) interconnecting the anchor assembly
with the
receiver of the support, wherein the anchor assembly is unlocked within the
receiver; 5)
compressing or distracting the base of the screw assembly and the base of the
anchor
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assembly in relation to each other (e.g. to achieve a parallel displacement of
the
instrumented vertebrae (); 6) locking the anchor assembly within the support
(e.g. using a
setscrew or cam); and 7) locking the support position in relation to the base
using the
screw assembly locking means (e.g. using a setscrew or cam).
[00124] The term "instrumented" as used herein defines a physical connection
between a structure (e.g. a vertebra) and a medical device or instrument.
[00125] A method of use of the invention for effecting a desired curvature of
the
spine can include the steps of: implanting a screw assembly comprising a
support having
a receiver, a base, an interconnection means, and a locking means into a
vertebra; 2)
deploying the support substantially perpendicular to the long axis of the
base; 3) passing
through the support and implanting one or more anchor assemblies having a base
and a
locking means into a vertebra; 4) interconnecting the anchor assembly with the
receiver
of the support, wherein the anchor assembly is unlocked within the receiver;
5)
compressing or distracting the bases in relation to each other (e.g. to affect
the
lordotic/kyphotic curvature of the spine); 6) locking the anchor assembly
within the
support (e.g. using a setscrew or cam); and 7) locking the support position in
relation to
the base using the screw assembly locking means (e.g. using a setscrew or
cam).
[00126] As shown in FIGS. 11A-11C and 11E, a screw assembly 1101 is provided
including a base 1102 and one or more arms 1103 in a single unit. The arm 1103
and base
1102 of the screw assembly 1101 are coupled by an interconnection means. The
base
1102 of the screw assembly 1101 is configured for attachment to a structure
(e.g., a bone)
and the arm 1103 is configured for attachment to a support structure
(described in detail
below). In application, a screw assembly 1101 having one or more arms 1103 is
attached
to one or more support structures to form a support assembly 1301 (see FIGS.
13A and
13B). The support assembly 1301 can be used for temporary or permanent
implantation.
[00127] As shown in FIGS. 1 lA and 11B, the screw assembly 1101
interconnection means can facilitate free-rotational (or multiaxial) movement
of an ann
1103 in relation to the base 1102. The interconnection means can be selected
from any
number of means including but not limited to: a hinge means, a collet means,
and a pin.
As shown in FIGS. 11A and 11B, the interconnection means comprises a receiver
end
1112 disposed within a receiver 1202 of a base 1102. In.this implementation,
the arm
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1103 can have a substantially spherical-shaped receiver end 1112 connected to
a
complementary-shaped receiver 1202 in the base head 104. Additionally, the
base head
1104 can be closed or open (e.g. open-saddle as shown in FIG lA). The free-
rotational
arm 1103 movement facilitated by the interconnection means is substantially a
cone-
shaped range of movement having an axis about which such movement is centered
("cone
axis" hereinafter).
[00128] In use, the implementation as shown in FIGS. 11A and 11B can be used
to
provide support to a structure in a patient (e.g. a spine having a series of
vertebrae).
Where the structure supported is a spine, and the spine includes a long axis
("spinal axis"
hereinafter), the screw assembly 1101 can provide support to the spine
substantially
collinearly with the spinal axis. Specifically, the cone axis of movement of
the arm 1103
of the screw assembly 1101 can optionally be disposed so that the cone axis is
substantially collinear with the spinal axis. This arrangement provides a
degree of
adjustability when positioning the arm 1103 and base 1102 of the screw
assembly 1101 in
relation to the structure being supported (e.g. a series of vertebrae). For
example, where
three sequential vertebrae are to be supported by a support assembly 1301
including a
screw assembly 1101 having two arms 1103 and two support structures (described
in
detail below), the three points of attachment to the three vertebrae can be
substantially
linear. Alternatively, the three points of attachment are not necessarily
substantially
linear.
[00129] In another implementation, as shown in FIGS. 11C and 11E, the
interconnection means comprises one or more receiver ends) 1112 of one or more
arms)
103 disposed within a base head 1104 of a base 1102. In this implementation
the
interconnection means can facilitate movement between the arm 1103 and the
base 1102,
such that the arm 1103 is positionable in a first position that is parallel to
a long axis of
the base 1102 (shown in FIGS. 11D, 12B, and 12D) and positionable in a second
position
that is perpendicular to the long axis of the base 1102 (shown in FIG 11 C and
11E).
Additionally, the screw assembly 1101 interconnection means can facilitate
free-rotational
(or multiaxial) movement of an arm 1103 in relation to the base 1102. As
discussed
above, the free-rotational movement of the arm 1103 can be substantially a
cone-shaped
range of movement having a cone axis. In use, the implementation as shown in
FIGS.
11C and 11E can be used to provide support to a structure in a patient (e.g. a
spine having
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a series of vertebrae). As discussed for the implementation described above
and shown in
FIGS. 11A and 11B, the present implementation can provide support to the spine
substantially collinearly with the spinal axis. Optionally, as shown in FIGS.
12C and
12D, an implementation wherein support is provided substantially collinearly
with the
spinal axis can include a cone axis of movement of the arm 1103 of the screw
assembly
1101 disposed so that the cone axis is substantially perpendicular with the
spinal axis.
This arrangement provides a similar degree of arm 1103 adjustability and
advantages as
discussed above for the implementation shown in FIGS. 11C and 11E.
[00130] The screw assembly 1101 can be made of materials that are durable and
that can be implanted in a body, including titanium, stainless steel, carbon
fiber, etc. In
one implementation, the screw assembly 1101 is made of titanium. In another
implementation the screw assembly 1101 is made of a biocompatible material, a
reabsorbable material, or a combination of any of the foregoing materials. The
dimensions of the screw assembly 1101 vary with the application. In general,
in
implementations as shown in FIGS. 11C and 11E, wherein the arm 1103 is
positionable in
a first position that is substantially parallel to the long axis of the base
1102, the length of
the screw assembly 1101 is from substantially 20 to 1,000 millimeters. In one
implementation, the length is substantially between 50 and 400 millimeters. In
another
implementation, the screw assembly 1101 is sized for applications involving
support of
multiples levels of the posterior of the spine (see FIG. 14). In another
implementation, as
shown in FIGS. 11A and 11B, the length of the base 1102 is from substantially
20 to 100
millimeters and the length of the one or more arms 1103 is from substantially
20 to 600
millimeters. In another implementation the length of the base 1102 and the
length of the
arm 1103 are each from substantially between 20 and 600 millimeters. In
another
implementation, the combined length of the base 1102 and the arm 1103 is sized
for
applications involving support of multiple levels of the posterior of the
spine (see FIG.
14).
[00131] In one implementation, as shown in FIGS. 11D, 12B, and 12D, the screw
assembly 1101 includes a longitudinal aperture 1106. The longitudinal aperture
1106
traverses the length of the screw assembly 1101, and provides an aperture for
the passage
of instruments, tools, and guides (e.g. a K-wire) when the arm 1103 is
positioned in a first
position that is parallel to a long axis of the base 1102 (see FIG. 1D, 2B,
and 2D).
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[00132] As shown in FIGS. 1 lA-11C and 11E, the base 1102 of the screw
assembly 1101 is comprised of a base head 1104 and an anchor 1105. The anchor
1105
can be a screw, staple, hook, or nail, and can be of a type typically used for
bone
anchoring. Iri one implementation the anchor 1105 is a screw of a type for
insertion into a
pedicle of a vertebra (see FIGS. 11A-11C, 1 lE, 13A-13B and 14).
[00133] In one implementation, as shown in FIGS. 12A-12D, the interconnection
means for coupling the base to the arms is comprised of the base head 1104.
The base
head 1104 can include a receiver 1202 for receiving the receiver ends 112 of
the screw
assembly arms 1103. In another implementation, the base head 1104 is
configured for
hinged attachment of one or more screw assembly arms 1103 using a hinge means
(see,
e.g., as in FIGS. lA-1B)..
[00134] The base head 1104 can include a locking means. As shown in FIGS.
1 lA-11D and 12B-12D, the locking means can be a setscrew 1107. The base head
1104
can be designed to include an open-saddle (see FIGS. 11A and 11B) or closed
configuration (see FIGS. 11C -11E) for accommodating the locking means (e.g. a
setscrew 1107). In one implementation, the locking means is a setscrew 1107,
which
secures the base 1102 and the one or more arms 1103 of the screw assembly 1101
together.
[00135] In use, a screw assembly 1101 including a base 1102, one or more arms
1103 and a locking means can be pre-assembled for delivery to a structure.
Alternatively,
the screw assembly 1101 can be delivered as separate pieces for assembly at
the site of a
structure.
[00136] As shown in FIGS. 1 lA, 11B, 11D and 12B-12D, tightening the setscrew
1107 can effect locking of one or more arms 1103 into a position in relation
to the base
1102. In an implementation as shown in FIGS. 11D and 12B-12D, after one or
more
arms 1103 of a screw assembly 1101 are deployed from a first position that is
substantially parallel to a long axis of the base to a second position that is
substantially
perpendicular to the long axis of the base 1102, the setscrew 1107 can be
tightened to
effect locking of the one or more arms 1103 in the second position. In an
alternative
implementation, a cam (not shown) can be substituted for the setscrew 1107.
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[00137] In another implementation, as shown in FIG. 11A, wherein a single arm
1103 is connected to the base 1102, the setscrew 1107 can be tightened to
effect locking
of the arm 1103 into a position. In this implementation, the arm 1103 can have
a
substantially spherical-shaped receiver end 1112 connected to a complementary-
shaped
receiver 1202 in the base head 1104. The base head 1104 can be closed or open
(e.g.
open-saddle as shown in FIG. 11A). Tightening the setscrew 1107 can create a
load that
compresses the receiver end 1112 of the arm 1103 against the receiver 1202 to
effect
locking of the arm 1103 into a position. As shown in FIG. 12C, the receiver
1202 can be
a substantially spherical collet-type receiver. In such an implementation,
tightening the
setscrew 1107 creates a load that compresses the receiver end 1201 of the arm
1103
against the receiver 1202, thereby deflecting one or more deformable fingers
1204 around
the receiver end 1112 to effect locking of the arm 1103 into a position (see
FIG. 12C).
[00138] In another implementation, as shown in FIG. 11B, wherein two arms 1103
are connected to the base 1102, the setscrew 1107 can be tightened to effect
locking of
both arms 1103 into a position. In this implementation, a first arm 1103 can
include a
substantially spherical collet-type receiver end 1201 and the second arm can
include a
receiver end 1112 configured to interconnect within the receiver end 1201 (see
FIG. 12C
and 12D). As shown in FIG. 12C, tightening the setscrew 1107 can create a load
that
compresses the receiver end 1201 of the first arm 1103 against the receiver
end 1112 of
the second arm 1103, thereby deflecting one or more deformable fingers 1204 of
the
receiver end 1201 around the receiver end 1112 of the second arm 1103 to
effect
simultaneous locking of both arms 1103 into a position.
[00139] The receiver end 1201 of the first arm 1103 and the receiver end 1112
of
the second arm 1103 can also be configured to provide for step-wise locking of
each arm
1103 into a position in relation to the base head 1104. For example, the
receiver end
1201 of the first arm can be configured such that initial tightening creates a
load that
compresses the receiver end 1112 against the base head receiver 1202 to effect
locking of
the first arm 1103 into a position without affecting the free rotational
movement of the
second arm 1103. Upon final tightening, the increased load created thereby can
compresses the receiver end 1201 of the first arm 1103 against the receiver
end 1112 of
the second arm 1103, thereby deflecting one or more deformable fingers 1204 of
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receiver end 1201 around the receiver end 1112 of the second arm 1103 to
effect locking
of the second arm 1103 into a position.
[00140] In another implementation, as shown in FIG. 11D, the setscrew 1107 can
be tightened to effect locking of a single arm 1103 having a cylindrical
shaped receiver
end 1112, by creating a load that compresses the receiver end 1112 of the arm
1103
against the complementary-shaped receiver 1202.
[00141] In yet another implementation, as shown in FIG. 12B, the setscrew 1107
can be tightened to effect locking of two arms 1103, wherein the first arm
1103 includes a
substantially cylindrical collet-type receiver end 1201 and the second arm
1103 (not
shown) includes a receiver end 1112 configured to interconnect within the
collet-type
receiver end 1201. In this implementation, tightening the setscrew 1107
creates a load
that compresses the substantially cylindrical collet-type receiver end 1201 of
the first arm
1103 against the receiver 1202 (see FIG. 12B), thereby deflecting one or more
deformable fingers 1204 (not shown) around the receiver end 1112 of the second
arm
1103 to effect locking of both arms 1103 into a position.
[00142] In a further implementation, as shown in FIG. 12C and 12D, the
setscrew
1107 can be tightened to effect locking of two arms 1103, wherein the first
arm 1103
includes a substantially spherical collet-type receiver end 1201 and the
second arm 1103
includes a receiver end 1112 configured to interconnect within the collet-type
receiver
end 1201. In this implementation, tightening the setscrew 1107 creates a load
that
compresses the substantially spherical collet-type receiver end 1201 of the
first arm 1103
against the receiver 1202, thereby deflecting one or more deformable fingers
1204 around
the receiver end 1112 of the second arm 1103 to effect locking of both arms
1103 into a
position (see FIG. 12C).
[00143] In another implementation, shown in FIGS. 11D, 12B and 12D, the
setscrew 1107 includes a setscrew aperture 1115. The setscrew aperture 1115
can be
configured to substantially align with the longitudinal aperture 1106 of the
base 1102,
thereby enabling through passage between the longitudinal aperture 1106 of the
arm 1103
and base 1102 (as discussed above).
[00144] As shown in FIGS. 11A-11D, and 13A-13B, the one or more arms 1103 of
the screw assembly 1101, include a body 1111 wherein the body 1111 has an
elongate
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shape and includes a connector end 110 for attachment to a support structure
1109, and a
receiver end 1112. In one implementation, the elongate shape of the body 1111
of the
arm 1103 is a rod. In another implementation, the elongate shape of the body
1111 of the
arm 1103 is substantially a longitudinally split rod. In another
implementation, the
elongate shape of the body 1111 of the arm 1103 is a shape configured for
fitted
interrelation between two or more arms 1103 positioned in a first position
that is
substantially parallel to a long axis of the base 1102 (not shown). For
example, the fitted
interrelation can be comprised of a longitudinally split rod shape.
[00145] In another implementation, as shown in FIGS. 11C-11E and 13A-13B, the
elongate shape of the body 1111 of the arm 1103 includes an offset section
1113. The
offset section 1113 can be configured to provide a low-profile to the screw
assembly 1101
when the one or more arms 1103 are positioned substantially parallel to a long
axis of the
base 1102 (See FIGS. 11D and 12B). Additionally, the offset section 1113 can
provide a
linear alignment of the base 1102 and the body 1111 of the arm 1103 when the
arm 1103
is positioned substantially parallel to a long axis of the base 1102 (See
FIGS. 11D and
12B).
[00146] In another implementation, as shown in FIGS. 11D, 12B and 12D, the
body 1111 of the arm 1103 includes a longitudinal aperture 1106. In one
implementation,
the longitudinal aperture 1106 is a channel or groove running the length of
the body 1111
of the arm 1103 (not shown). In a further implementation, two interrelating
arms 1103
can have longitudinal apertures 106 that align to form a single longitudinal
aperture 1106
when the arms 1103 are interrelated. The longitudinal aperture 1106 of the
body 1111 of
the arm 1103 can be coaxially aligned with the longitudinal aperture 1106 of
the base
1102 of the screw assembly 1101. The longitudinal aperture 1106 traverses the
length of
the screw assembly 1101, and provides an aperture for the passage of
instruments, tools,
and guides (e.g. a K-wire)
[00147] The receiver ends 1112 of the one or more arms 1103 can include a
hinge
means for hinged interconnection with the base head 1104 e.g., as shown in
FIGS. 1 lA-
11B. In such an implementation, a locking means can be provided whereby after
deployment, the one or more arms 1103 are lockable into a position
substantially
perpendicular to the long axis of the base 1102. An example of such a locking
means can
be a one-way ratchet configuration (not shown).
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[00148] In another implementation, the receiver end 1112 of a single arm 1103
can
be cylindrical shape for interconnection within the receiver 1202 of the base
head 1104.
In such an implementation the receiver 1202 can be an aperture in which the
receiver end
1112 of the arm 1103 is received.
[00149] In another implementation, the receiver ends 1112 of two arms 1103 can
be interconnecting and disposed within the base head 1104. For example, the
receiver
ends 1112 can interconnect by way of a collet-type design. In a first example,
the two
interconnecting receiver ends 1112 can have a cylindrical-shaped collet-type
design
including: a first collet-type receiver end 1201 having a substantially
cylindrical recess,
one or more relief cuts 1203 and one or more deformable fingers 1204, and; a
second
solid cylindrical-shaped receiver end 1112 configured for fitting into the
cylindrical
recess of the collet-type receiver end 1201 (not shown).
[00150] In a second example, as shown in FIGS. 11A, 11B, 12C and 12D, the two
interconnecting receiver ends 1112 can have a spherical-shaped collet-type
design
including: a first collet-type receiver end 1201 having a substantially
spherical recess, one
or more relief cuts 1203 and one or more deformable fingers 1204, and; a
second solid
spherical-shaped receiver end 1112 configured for fitting into the first
collet-type receiver
end 1201.
[00151] Additionally, as shown in FIGS. 12A and 12B, which illustrate a
cylindrical shaped collet-type design, and FIGS. 12C and 12D, which illustrate
a
spherical-shaped collet-type design, the respective receiver ends 1112 can
include a
longitudinal aperture 1106 passing through the interconnected receiver ends
1112. Such a
longitudinal aperture 1106 can be configured to provide coaxial alignment with
the
longitudinal aperture 1106 of the base 1102, when the arms 1103 are positioned
substantially parallel to the long axis of the base 1102 (see FIGS. 12B and
12D).
[00152] As shown in FIGS. 11A-11D, 13A and 13B, the connector ends 1108 of
the one or more arms 1103 are configured for attachment to a support structure
1109. As
shown in FIGS. 13A and 13B, one or more support structures 1109 can be
attached to a
screw assembly 1101 to provide a support assembly 1301. In one implementation,
each
support structure 1109 is comprised of an anchor 1105, an aperture 1110, and a
locking
means (see FIGS. 13A and 13B). The one or more support structures 1109 can be
made
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of materials that are durable and that can be implanted in a body, including
titanium,
stainless steel, carbon fiber, etc. In one implementation, the one or more
support
structures 1109 are made of titanium. In another implementation the one or
more support
structures 1109 are made of a biocompatible material, a reabsorbable material,
or a
combination of any of the foregoing materials.
[00153] In one implementation, each support structure 1109 is configured for
attachment to a structure in a patient (e.g. bone). As shown in FIGS. 13A and
13B, the
locking means for the one or more support structures 1109 can be a setscrew
1107.
Alternatively, the locking means can be a cam (not shown).
[00154] As shown in FIG. 14, two support structures 1109 can be attached to a
screw assembly 1101 to provide a support assembly 1301 that can be implanted
into the
pedicles 1403 of vertebra 1402 in a spine 1401 to effect support of the spine
1401. In
another implementation, a single support structure 1109 can be attached to a
screw
assembly 1101 to provide a support assembly 1301 that can be implanted into
the pedicles
1403 of vertebra 1402 in a spine 1401 to effect support of the spine 1401.
[00155] Refernng to FIGS. 13A, 13B and 14, a method of using the invention to
support the spine 1401 includes the steps of 1) delivering to bone a screw
assembly 1101
having one or more arms 1103, a base 1102 and an interconnection means (e.g. a
base
head receiver 1202 interconnected with the receiver end 1112 of one or more
arms 1103);
2) delivering to flanking bone, one or more support structures 1109 having
apertures 1110
and locking means for the connector ends 110 of the arms 1103 of the screw
assemblies
101; 3) deploying the one or more arms 1103 of the screw assembly 1101 to the
flanking
support structures 1109; 4) locking the one or more arms 1103 of the screw
assembly
1101 in a desired position; and 5) engaging the locking means of the support
structure
1109 apertures 1110. In one implementation, the one or more flanking support
structures
1109 can be delivered, for example, to bone including one or more vertebral
bodies on
one or both sides of a vertebral body to which the screw assembly 1101 is
delivered. In
another implementation, the one or more flanking support structures 1109 are
delivered to
vertebral bodies adjacent to the vertebral body to which the screw assembly
1101 is
delivered. In another implementation, one or more of the flanking support
structures
1109 are delivered to vertebral bodies distal to the adjacent-most vertebral
body.
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[00156] The method of supporting the spine can also be used in conjunction
with a
kyphoplasty procedure. Kyphoplasty is a percutaneous technique involving the
use of an
expandable structure, such as a balloon catheter, to create a cavity or void
within the
vertebral body, followed by filling the cavity with a bone substitute to form
an "internal
cast". The bone substitute could be any appropriate filling materials used in
orthopedic
surgery, including but not limited to, allograft or autograft tissue,
hydroxyapatite, epoxy,
PMMA bone cement or synthetic bone substitutes, medical grade plaster of Paris
or
calcium phosphate or calcium sulfate cements. Methods and instruments suitable
for
such treatment are more fully described in U.S. Pat. Nos. 4,969,888 and
5,108,404.
Kyphoplasty can be used to reduce vertebral compression fractures and to move
bone
with precision, thus restoring as close to normal the pre-fracture anatomy of
the vertebral
body. Vertebral compression fractures caused by trauma (for example, due to
automobile
accidents or falls) have traditionally been treated with open reduction,
internal fixation
stabilization hardware and ftision techniques using a posterior approach. The
stabilization
hardware is used to offload the fractured vertebral body and to stop motion
across the
disk so that bone graft can fuse one vertebral body to the next and the
stabilization
hardware usually becomes a permanent implant. In trauma, the stabilization
hardware
may be designed to facilitate easy removal after fusion has occurred.
Stabilization
hardware can take many forms, including those described herein.
[00157] The combination of kyphoplasty and insertion of stabilization hardware
utilizing the naturally occurnng interior muscle plane as described in Wiltse
and Spencer,
Spine (1988) 13(6):696-706, satisfies the goals of improving the quality of
patient care
through minimally invasive surgical therapy.
[00158] A number of preferred embodiments of the invention have been
described.
Nevertheless, it will be understood that various modifications may be made
without
departing from the spirit and scope of the invention. For example, while the
some
implementations have been described using screws to anchor into bony
structures, the
scope of the invention is not so limited. Any means of anchoring can be used,
such as a
cam, screw, staple, nail, pin, or hook. Accordingly, other embodiments are
within the
scope of the following claims.
