U.S. patent application number 10/256636 was filed with the patent office on 2004-05-13 for screw placement guide.
Invention is credited to Breech, Carrie A., Gracia, Mark, Newton, Peter, Varieur, Michael S..
Application Number | 20040092952 10/256636 |
Document ID | / |
Family ID | 31498108 |
Filed Date | 2004-05-13 |
United States Patent
Application |
20040092952 |
Kind Code |
A1 |
Newton, Peter ; et
al. |
May 13, 2004 |
Screw placement guide
Abstract
A screw placement guide tool for use in minimally invasive
surgery has a proximal handle portion, an extension member
extending distally from the handle portion, and an alignment
element connected transversely to a distal portion of the extension
member and having a screw placement guide located thereon. In this
aspect of the invention, the tool is configured so that a surgeon
may operate the tool using the handle portion external to a
patient's body to align the alignment element with implanted screws
so that the screw placement guide indicates a desired position for
implantation of an additional screw. Systems and methods for
placing a rod receiving screw are also provided.
Inventors: |
Newton, Peter; (San Diego,
CA) ; Gracia, Mark; (Rochester, MA) ; Varieur,
Michael S.; (Portsmouth, RI) ; Breech, Carrie A.;
(Wrentham, MA) |
Correspondence
Address: |
NUTTER MCCLENNEN & FISH LLP
WORLD TRADE CENTER WEST
155 SEAPORT BOULEVARD
BOSTON
MA
02210-2604
US
|
Family ID: |
31498108 |
Appl. No.: |
10/256636 |
Filed: |
September 27, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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60400912 |
Aug 2, 2002 |
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Current U.S.
Class: |
606/104 |
Current CPC
Class: |
A61B 2017/00238
20130101; A61B 17/1757 20130101 |
Class at
Publication: |
606/104 |
International
Class: |
A61F 002/38 |
Claims
What is claimed is:
1. A screw placement guide tool for use in minimally invasive
surgery, comprising: a proximal handle portion; an extension member
extending distally from the handle portion; and an alignment
element connected transversely to a distal portion of the extension
member and having a screw placement guide located thereon; wherein
the tool is configured so that a surgeon may operate the tool using
the handle portion external to a patient's body to align the
alignment element with implanted screws so that the screw placement
guide indicates a desired position for implantation of an
additional screw.
2. The tool of claim 1, wherein the alignment element is curved to
correspond to a curve of a spinal fixation rod to be implanted.
3. The tool of claim 1, wherein the screw placement guide is a
closed loop.
4. The tool of claim 1, wherein the alignment element is elongate,
has first and second opposed ends, is connected to the extension
member at a first opposed end, and has the screw placement guide
located on the second opposed end.
5. The tool of claim 4, wherein a curved portion connects the
extension member to the alignment element.
6. A system for placing a rod receiving screw within a patient's
bone, comprising: a plurality of rod receiving screws, each rod
receiving screw having a proximal rod receiving opening and a
distal bone attachment portion; a screw placement guide tool having
an elongate alignment element including a screw placement guide
located thereon, the elongate alignment element being sized to fit
within the rod receiving opening of at least one of the plurality
rod receiving screws when the at least one rod receiving screw is
implanted and to extend so that the screw placement guide indicates
a placement location for another of the plurality of rod receiving
screws.
7. The system of claim 6, wherein the plurality of rod receiving
screws includes at least three rod receiving screws and the
elongate alignment element is sized to fit within the rod receiving
openings of at least two of the at least three rod receiving screws
when the at least two rod receiving screws are implanted and to
extend so that the screw placement guide indicates a placement
location for a third of the at least three rod receiving
screws.
8. The system of claim 6, wherein the screw placement guide tool
further includes an extension member extending proximally from the
alignment element and a handle disposed on a proximal portion of
the alignment element.
9. The system of claim 6, wherein the alignment element is curved
to correspond to a curve of a spinal fixation rod to be
implanted.
10. The system of claim 6, wherein the screw placement guide is a
closed loop.
11. The system of claim 6, wherein the alignment element has first
and second opposed ends, is connected to the extension member at a
first opposed end, and has the screw placement guide located on the
second opposed end.
12. The system of claim 6, further including a marking tool, the
marking tool being guidable to a location indicated by the screw
placement guide for placing an indication on a patient's bone where
a screw is to be implanted.
13. A method for placing a rod receiving screw for implantation in
a vertebral body, comprising: implanting at least one rod receiving
screw into a patient's spine, each of the at least one rod
receiving screws having a distal bone attachment element and a
proximal rod receiving opening; and fitting a screw placement guide
tool having an elongate alignment element including a screw
placement guide located thereon within the rod receiving opening of
the at least one implanted rod receiving screw so that the screw
placement guide indicates a placement location for another rod
receiving screw.
14. The method of claim 13, wherein at least two rod receiving
screws are implanted into a patient's spine and the screw placement
guide tool is fitted to the rod receiving openings of the at least
two implanted rod receiving screws so that the placement guide
indicates a placement location for a third rod receiving screw.
15. The method of claim 13, wherein the screw placement guide tool
further includes an extension member extending proximally from the
alignment element and a handle disposed on a proximal portion of
the alignment element so that a surgeon may operate the tool using
the handle portion external to a patient's body to fit the
alignment element within the rod receiving openings of the at least
two implanted rod receiving screws.
16. The method of claim 13, further comprising curving the
alignment element to correspond to a curve of a spinal fixation rod
to be implanted.
17. The method of claim 13, wherein the alignment element has first
and second opposed ends, is connected to the extension member at a
first opposed end, and has the screw placement guide located on the
second opposed end.
18. The method of claim 13, further comprising: guiding a marking
tool to a location indicated by the screw placement guide; and
placing an indication on a patient's bone where a screw is to be
implanted using the marking tool.
Description
RELATED APPLICATIONS
[0001] This application claims priority to provisional application
U.S. Ser. No. 60/400,912, filed Aug. 2, 2002.
FIELD OF THE INVENTION
[0002] The present invention relates to devices and methods for
placing a screw to be inserted in a patient's vertebrae during
spinal fixation surgery.
BACKGROUND OF THE INVENTION
[0003] The use of spinal fixation instrumentation to align and/or
fix a desired relationship between adjacent vertebral bodies is
well established. Such instrumentation typically includes a spinal
fixation element, such as a relatively rigid fixation rod, that is
coupled to adjacent vertebrae by attaching the element to screws
which have been inserted into the patient's vertebrae or to spinal
hooks which can be placed into a vertebral arch for coupling to the
vertebral bodies. Once installed, the spinal fixation
instrumentation holds the vertebrae in a desired spatial
relationship, either until desired healing or spinal fusion has
taken place, or for some longer period of time.
[0004] One example of a rod based spinal fixation system is
provided in U.S. Pat. No. 5,005,562, issued Apr. 9, 1991 to Cotrel
(which is hereby incorporated by reference). This system includes
pedicle screws and spinal hook vertebral coupling elements (both
screws and hooks) having integral U-shaped bodies that extend
outward from the vertebrae to which they are attached. A spinal
fixation rod is shaped as desired and fitted into the "U" of
U-shaped bodies of adjacent vertebrae. The inner surfaces of the
U-shaped body are threaded to accept a set screw, and rod is fixed
to the vertebral coupling elements by threading a set screw into
each of the U-shaped bodies to lock in the rod.
[0005] U.S. Pat. No. 5,545,165, issued Aug. 13, 1996 to Biedermann
et al. (and incorporated herein by reference), illustrates an
improvement in closure systems for fixing a rod to vertebral
coupling elements over those provided by Cotrel. The Biedermann et
al. system also uses pedicle screws and spinal hooks having
U-shaped bodies that extend outward from the vertebrae to which
they are attached. The U-shaped bodies of the Biedermann et al.
system are threaded on both the inside and the outside. The rod is
therefore locked in by both an inner set screw and an outer lock
nut. In the illustrated embodiments, the inner set screw is adapted
to be driven on its threads using a hex-shaped driver element, and
the outer locking nut is provided with hex-shaped flat outer
surfaces suitable for engagement with a wrench or similar driving
tool.
[0006] U.S. Pat. No. 5,443,467, issued Aug. 22, 1995 to Biedermann
et al. (and incorporated herein by reference) illustrates the use
of an inner set screw and an outer lock nut to lock a rod into a
U-shaped body in a polyaxial screw system. In this system, a
pedicle screw having a spherical head is captured within a separate
U-shaped receiver body. The angle of the screw with respect to the
body can be changed until a head-locking element is tightened to
lock the angle of the screw head within the receiver body.
According to Biedermann et al., this combination of an inner set
screw and an outer locking nut provides an advantage in that the
force acting on the rod can be independently adjusted by either the
inner set screw or the outer locking nut--a particularly useful
advantage where the rod being fastened is curved and an exact
fastening might only be possible by independent adjustment of the
two closure elements. In addition, when tightened, the inner set
screw and the outer locking nut tend to lock each other in their
tightened positions.
[0007] The effectiveness of these spinal fixation systems and
others depend upon the rod receiving screws being properly placed.
If the rod receiving screws are out of line, the surgeon will be
able to place the rod within the receiving portions of the screw
assemblies only by placing a load on the screw in order to move it
into line to accept the rod. Such loads can result in improper
alignment of the vertebrae, premature screw pull out, and fracture
of the bone to which the screw is attached.
[0008] Accordingly, there is a need for a system, method and/or
device to allow the surgeon to place the rod receiving screws in
proper alignment before the rod is fitted to them.
SUMMARY OF THE INVENTION
[0009] The present invention provides a system, device and method
for placing rod receiving screws for implantation in spinal
fixation surgery to ensure that rod receiving screws are properly
placed so that, as a result of ensuring correct screw placement,
surgeons will not need to apply undue force to orient the rod
receiving screws to receive the spinal fixation rod to be
implanted. The system, device and method of the invention can be
advantageously adapted to be particularly useful in minimally
invasive surgery. In a first aspect of the invention, a screw
placement guide tool for use in minimally invasive surgery is
provided having a proximal handle portion, an extension member
extending distally from the handle portion, and an alignment
element connected transversely to a distal portion of the extension
member and having a screw placement guide located thereon. In this
aspect of the invention, the tool is configured so that a surgeon
may operate the tool using the handle portion external to a
patient's body to align the alignment element with implanted screws
so that the screw placement guide indicates a desired position for
implantation of an additional screw.
[0010] In particular embodiments of the invention, the alignment
element can be curved to correspond to a curve of a spinal fixation
rod to be implanted. The alignment element can also be configured
to be elongate with first and second opposed ends and to be
connected to the extension member at a first opposed end with the
screw placement guide located on the second opposed end. A curved
portion can also connect the extension member to the alignment
element. In one embodiment, the screw placement guide is a closed
loop.
[0011] In a further aspect of the invention, a system for placing a
rod receiving screw within a patient's bone is provided. The system
includes a plurality of rod receiving screws with each rod
receiving screw having a proximal rod receiving opening and a
distal bone attachment portion, and a screw placement guide tool.
The screw placement guide tool has an elongate alignment element
including a screw placement guide located thereon. The elongate
alignment element is sized to fit within the rod receiving opening
of at least one of the plurality of rod receiving screws when the
at least one rod receiving screw is implanted and to extend so that
the screw placement guide indicates a placement location for
another of the plurality of rod receiving screws. In a further
embodiment, at least three rod receiving screws are provided and
the alignment element is sized to fit within the rod receiving
opening of at least two of the at least three rod receiving screws
when the at least two rod receiving screws are implanted and to
extend so that the screw placement guide indicates a placement
location for a third rod receiving screw.
[0012] In one embodiment of the invention, the system further
includes a marking tool that is guidable to a location indicated by
the screw placement guide for placing an indication on a patient's
bone where a screw is to be implanted. In further particular
embodiments, the screw placement guide tool can include a
proximally extending extension member with a handle and the
alignment element can be curved to correspond to a curve of a
spinal fixation rod to be implanted. The alignment element can also
be configured to be elongate with first and second opposed ends and
to be connected to the extension member at a first opposed end with
the screw placement guide located on the second opposed end.
[0013] In a still further aspect of the invention, a method for
placing a rod receiving screw for implantation in a vertebral body
is provided. In the method, at least one rod receiving screw is
implanted into a patient's spine with each screw having a distal
bone attachment element and a proximal rod receiving opening. A
screw placement guide tool having an elongate alignment element
including a screw placement guide located thereon is then fitted
within the rod receiving opening of the at least one implanted rod
receiving screw so that the screw placement guide indicates a
placement location for another receiving screw. In a further
embodiment, at least two rod receiving screws are implanted and the
alignment element is fitted within the rod receiving opening of the
at least two implanted rod receiving screws and to extend so that
the screw placement guide indicates a placement location for a
third rod receiving screw.
[0014] In a further embodiment, a marking tool is also provided and
guided to a location indicated by the screw placement guide and an
indication is placed on a patient's bone where a screw is to be
implanted using the marking tool. In further particular
embodiments, the screw placement guide tool can include a
proximally extending extension member with a handle and the
alignment element can be curved to correspond to a curve of a
spinal fixation rod to be implanted. The alignment element can also
be configured to be elongate with first and second opposed ends and
to be connected to the extension member at a first opposed end with
the screw placement guide located on the second opposed end.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The invention will be more fully understood from the
following detailed description taken in conjunction with the
accompanying drawings:
[0016] FIG. 1 a side view of a screw placement guide of the
invention;
[0017] FIG. 2 is a perspective view of the screw placement guide of
FIG. 1;
[0018] FIG. 3 illustrates the screw placement guide of FIG. 1 along
with two rod receiving screws locating a placement for a third rod
receiving screw on a patient's spine; and
[0019] FIG. 4 illustrates the screw placement guide of FIG. 1 along
with two rod receiving screws and a marking tool for marking the
location for the placement of a third rod receiving screw on a
patient's spine.
DETAILED DESCRIPTION OF THE INVENTION
[0020] The present invention provides a system, device and method
for placing rod receiving screws for implantation in spinal
fixation surgery. The system, device and method of the invention
can be configured to be particularly useful in minimally invasive
surgery to ensure that rod receiving screws are properly placed so
that, as a result of ensuring correct screw placement, surgeons
will not need to apply undue force to orient the rod receiving
screws to receive the spinal fixation rod to be implanted.
[0021] A screw placement guide tool 10 of the invention is
illustrated in side and perspective views in FIGS. 1 and 2,
respectively. Guide tool 10 includes an elongate alignment element
12 having a placement guide 14 disposed thereon. Placement guide 14
is shown as a closed loop, however, any guide or directional marker
useful for placing a screw may be used. For example, placement
guide 14 could simply be a blunt end against which a rod receiving
screw could be aligned for placement into a patient's spine.
Placement guide 14 could also provide an element for marking the
bone to indicate where the screw is to be placed, or could itself
be a screw holder or screw guide.
[0022] In the illustrated embodiment, guide tool 10 also includes
an extension element 16 that extends substantially transversely and
proximally from alignment element 12, connected to the alignment
element by curved portion 18 that is designed to move through a
patient without damaging nearby tissue. Extension element 16 may
also include a proximal handle 20 for gripping by a surgeon. While
alignment element 12 and extension member 16 are shown
perpendicular to each other, a person of ordinary skill in the art
will recognize that these elements could connect at any angle
appropriate to the surgical procedure in which the tool is used,
and that for some procedures, handle 20 and/or extension member 16
may not be required.
[0023] A system and method for placing a screw using screw
placement guide 10 is illustrated by reference to FIGS. 3 and 4. In
FIG. 3, two screws 22, 24 have been-placed into vertebral bodies
26, 28, respectively, in a patient's spine 30. Each of screws 22,
24 include a bone attaching element and a "U" shaped receiving
member 32, 34, respectively, connected to or integral with them. As
illustrated, screw placement guide 10 has been placed so that
alignment element 12 rests within each of U-shaped receiving
members 32, 34 and extends over a third vertebral body 36 into
which a screw will be placed.
[0024] In order to perform its intended functions, alignment
element 12 will generally be sized to fit within the U-shaped
receiving members, having a diameter that is substantially the same
as or, more preferably, slightly smaller than the diameter of the
spinal fixation rod that will be employed, often in the range of
approximately {fraction (3/16)} to 1/4 inches. In addition,
alignment element 12 should be of a sufficient length to rest
within two U-shaped receiving members and still extend to an
additional screw placement site. In one preferred embodiment,
alignment element 12 is about 60 millimeters in length. Alignment
element 12 can also be shaped so as to have the same contour that a
spinal fixation rod to be implanted will take. To that end,
alignment element 12 can be contoured using the same rod template
that will be used to contour the spinal fixation rod to be
implanted.
[0025] Turning to FIG. 4, screw placement tool 10 is illustrated
having extension element 16 and proximal handle 20 as they might be
configured for use in minimally invasive surgery. In this
configuration, extension element 16 and handle 20 may extend
approximately 200 to 400 millimeters proximally from alignment
element 12 in its working position as illustrated. In this way, a
surgeon can insert alignment element 12, then extension element 16
into an incision or portal being used to perform the surgery, and
can operate the placement tool from outside the patient's body
using handle 20.
[0026] In addition, an awl or marking tool 40 can be provided
having an extension element 42 with a proximal handle 44 and a
distal marking element 46 attached thereto. While in some
embodiments, the screw may be placed directly in vertebral body 36
based on an indication from alignment element 12, marking tool 40
may also be used to extend through the eyelet of illustrated
placement guide 14 to mark (in the illustrated case by scoring or
punching a small hole) the place where a screw will be implanted.
Marking tool 40 and screw placement guide 10 can then be removed
and the screw may be implanted as marked on vertebral body 36.
Where marking tool 40 is an awl, it can be used to start a hole
that the surgeon can either tap through or insert the screw
into.
[0027] While the embodiments of the invention illustrated in FIGS.
3 and 4 show screw placement tool 10 being aligned with two rod
receiving screws to locate the placement of a third screw, screw
placement tool 10 could readily be used with one implanted rod
receiving screw to locate the placement of a second screw. To do
so, a first rod receiving screw such as screw 22 is implanted. Tool
10 is then fitted so that its alignment element 12 is aligned
within rod receiving opening 32 and placement guide 14 is located
over vertebral body 28 to locate a desired location for implanting
a second screw. The location for the second screw can then be
marked and/or the screw implanted as described above.
[0028] A person of ordinary skill in the art will appreciate
further features and advantages of the invention based on the
above-described embodiments. For example, the invention may be
applied using a variety of bone attachment devices used in spinal
rod fixation including, but not limited to, each of the screws
described in the Cotrel and Biedermann patents incorporated by
reference above. Accordingly, the invention is not to be limited by
what has been particularly shown and described, except as indicated
by the appended claims. All publications and references cited
herein are expressly incorporated herein by reference in their
entity.
* * * * *