U.S. patent application number 14/739266 was filed with the patent office on 2015-10-01 for screw with anchor features.
The applicant listed for this patent is GLOBUS MEDICAL, INC.. Invention is credited to Sean Suh.
Application Number | 20150272633 14/739266 |
Document ID | / |
Family ID | 48086502 |
Filed Date | 2015-10-01 |
United States Patent
Application |
20150272633 |
Kind Code |
A1 |
Suh; Sean |
October 1, 2015 |
SCREW WITH ANCHOR FEATURES
Abstract
Screws for anchoring in cancellous or other low-quality bone are
described. One type of screw addresses the problem of extravasation
of bone cement when filling an area of low-quality bone. The screw
includes an expandable container for retaining bone cement and
anchoring the screw in low-quality bone. The screw also includes an
anchoring device for holding the screw in place in the bone while
it is supplied with bone cement or other appropriate filler. The
screw further includes a head for connecting to a rod or other
apparatus. A second type of screw uses an expandable container to
deform two or more fins to compress cancellous bone and/or anchor
in cancellous bone.
Inventors: |
Suh; Sean; (Jamesburg,
NJ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GLOBUS MEDICAL, INC. |
AUDUBON |
PA |
US |
|
|
Family ID: |
48086502 |
Appl. No.: |
14/739266 |
Filed: |
June 15, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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13271373 |
Oct 12, 2011 |
9084647 |
|
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14739266 |
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Current U.S.
Class: |
606/323 |
Current CPC
Class: |
A61B 17/864 20130101;
A61B 17/7097 20130101; A61B 17/8841 20130101; A61B 17/8811
20130101; A61B 2017/8655 20130101; A61B 17/8805 20130101; A61B
17/844 20130101 |
International
Class: |
A61B 17/70 20060101
A61B017/70; A61B 17/84 20060101 A61B017/84; A61B 17/86 20060101
A61B017/86; A61B 17/88 20060101 A61B017/88 |
Claims
1. A surgical method comprising: inserting an expandable screw into
bone, wherein the expandable screw comprises: a head portion; a
body portion distally attached to the head portion; and an
expandable portion distally attached to the body portion; attaching
a fluid source to the expandable screw, wherein the fluid source
comprises: a reservoir; and a tube extending from the reservoir;
and injecting a fluid source into the expandable screw, thereby
causing the expandable portion to expand in width within the
bone.
2. The surgical method of claim 1, wherein the head portion
comprises a receiver for receiving the fluid source.
3. The surgical method of claim 1, wherein the body portion
comprises threads.
4. The surgical method of claim 1, wherein the expandable portion
comprises a plurality of fins that can change shape or deform.
5. The surgical method of claim 4, wherein the expandable screw
further comprises a container received within the plurality of
fins, wherein the container is configured to receive fluid from the
fluid source to push the plurality of fins outward into bone.
6. The surgical method of claim 5, wherein the fluid received in
the container is bone cement (PMMA).
7. The surgical method of claim 1, wherein the expandable screw is
inserted into cancellous bone.
8. The surgical method of claim 1, wherein the expandable portion
comprises one or more fins connected to a knob.
9. The surgical method of claim 1, wherein the expandable portion
comprises one or more fins that can assume a convex shape when
expanded.
10. The surgical method of claim 1, wherein the reservoir is
pressurized.
11. A surgical method comprising: inserting an expandable screw
into bone, wherein the expandable screw comprises: a head portion;
a body portion distally attached to the head portion; and an
expandable portion distally attached to the body portion, wherein a
container is received within the expandable portion; attaching a
fluid source to the expandable screw, wherein the fluid source
comprises: a reservoir; and a tube extending from the reservoir;
and injecting a fluid into the expandable screw, thereby causing
the expandable portion to expand in width within the bone.
12. The surgical method of claim 11, wherein the expandable screw
is inserted at least in part into cancellous bone.
13. The surgical method of claim 11, wherein the body portion
comprises a first set of threads and the expandable portion
comprises a second set of threads, wherein the first set of threads
are continuous with the second set of threads.
14. The surgical method of claim 11, wherein the expandable portion
comprises a plurality of fins that terminate in a screw tip.
15. The surgical method of claim 11, wherein the expandable portion
comprises a plurality of fins that are capable of expansion,
wherein fluid is injected into the container, which causes the
plurality of fins to expand outwardly.
16. The surgical method of claim 11, wherein expansion of the
expandable screw causes compression of cancellous bone.
17. The surgical method of claim 11, wherein the expandable portion
comprise a plurality of fins, wherein the fins are capable of
curving convexly.
18. The surgical method of claim 11, wherein the expandable portion
comprises a plurality of fins capable of expansion, wherein in a
non-expanded state the fins are straight and in an expanded state
the fins are curved.
19. The surgical method of claim 11, wherein the reservoir is
pressurized.
20. The surgical method of claim 11, wherein the fluid received in
the container is bone cement (PMMA).
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation application of U.S.
patent application Ser. No. 13/271,373, filed Oct. 12, 2011, which
is hereby incorporated by reference in its entirety.
BACKGROUND OF THE DISCLOSURE
[0002] 1. Field of the Disclosure
[0003] The disclosure is directed to bone screws with anchor
features for securely attaching to low-quality cancellous bone,
such as may be found, for example, in a vertebral body of a patient
with osteoporosis.
[0004] 2. Related Art
[0005] Pedicle screws are commonly used to attach a spinal fusion
apparatus to a patient's spine. The screws are bored through
cortical bone of the pedicle and place their distal portion in the
cancellous bone of the vertebral body. The portion of the screw
anchored in cancellous bone may be as much as 50%. The quality of
the cancellous bone is therefore critical for the overall stability
of the apparatus, as well as the success of the fusion process.
[0006] Several factors may reduce the quality of the cancellous
bone. The patient's age is the most common factor. Diseases and
injuries, such as, e.g., osteoporosis and vertical compression
fractures, can further reduce the bone quality.
[0007] In patients with low-quality cancellous bone, the common
solution is to fill the vertebral body with bone cement. This
solution, however, may be inadequate due to extravasation of the
bone cement. In addition, low-quality cortical bone on the outside
of the vertebral body may not retain all of bone cement.
[0008] Accordingly, there is a need for pedicle screws that retain
bone cement or provide alternative means of anchoring in
low-quality bone.
SUMMARY OF THE DISCLOSURE
[0009] The disclosure meets the foregoing need and allows pedicle
screws to anchor in low-quality cancellous bone using an expandable
container, which results in a significant increase in the strength
of bone-screw interface and the overall anchorage of the screw, as
well as other advantages apparent from the discussion herein.
[0010] According to one aspect of the invention, a screw for
anchoring in cancellous bone includes a screw head including a
receiver, a distal end, and a proximal end, the proximal end
configured as a channel, an anchoring device connected to the
distal end of the screw head, an expandable container, and a neck
connected to the temporary anchoring device and to the expandable
container.
[0011] According to another aspect of the invention, a screw for
anchoring in cancellous bone includes a body including bone
threads, a proximal end, and a distal end, a head connected to the
proximal end of the body, the head including a receiver, a
plurality of fins connected to the distal end of the body, the
plurality of fins defining an interior space, and an expandable
container located in the interior space.
[0012] Accordingly, one aspect of the disclosure describes a screw
for anchoring in cancellous or other low-quality bone. The screw
includes a screw head with a receiver, a proximal end and a distal
end. The proximal end of the screw head is structured to accept a
lumen. A temporary anchoring device is connected to the distal end
of the screw head. The screw also includes an expandable container
and a neck connecting the temporary anchoring device to the
expandable container.
[0013] A delivery adapter may be provided for connecting to the
screw. The delivery adapter may include a body with a proximal end
and a distal end. A connector for connecting to the screw's
receiver may be attached to the distal end of the body. The
delivery adapter may also include a filler arm connected to the
body.
[0014] The temporary anchoring device may include bone threads. The
receiver may include female threads. The screw itself may also
include a lumen from the receiver to the distal end of the
expandable container, as well as a filler space from the receiver
to the expandable container. The filler space may be in fluid
communication with the expandable container and separate and
distinct from the lumen.
[0015] A delivery adapter may be provided for connecting to the
screw. The delivery adapter may include a body with a proximal end
and a distal end. A connector for connecting to the screw's
receiver may be attached to the distal end of the body. A stylet
port may be located on the proximal end of the body. A lumen may
connect the stylet port to the connector, and the lumen may be
configured to connect to the lumen of the screw. The delivery
adapter may also include a filler arm, with both a proximal end and
a distal end, connected to the body at the distal end of the filler
arm. A filler port may be connected to the proximal end of the
filler arm. A filler space, separate and distinct from the lumen,
may connect the filler port to the connector. The filler space may
be configured to connect to the filler space of the screw at the
connector.
[0016] According to another aspect of the disclosure, a screw for
anchoring in cancellous or other low-quality bone includes a body
with bone threads, a proximal end, and a distal end. A screw head,
which includes a receiver, is connected to the proximal end of the
body. Two or more fins are connected to the distal end of the body
and define an interior space. An expandable container is located in
the interior space.
[0017] The head of the screw may be structured to accept a
polyaxial connector, a monoaxial connector, a fixed connector, or
any combination thereof. The screw may also include a screw tip
connected to the distal end of one or more fins. The fins may
include bone threads. The receiver may be structured to connect to
a fluid source and receive a pressurized fluid, which may be
saline, polymethyl methacrylate (PMMA), or any other appropriate
gas or liquid. The screw may include a channel structured and
arranged to convey the pressurized fluid from the receiver to the
expandable container. The expandable container may be expanded by
the pressurized fluid. The expansion of the container may cause the
deformation of one or more of the fins.
[0018] Additional features, advantages, and aspects of the
disclosure may be set forth or apparent from consideration of the
following detailed description, drawings, and claims. Moreover, it
is to be understood that both the foregoing summary of the
disclosure and the following detailed description are exemplary and
intended to provide further explanation without limiting the scope
of the disclosure as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The accompanying drawings, which are included to provide a
further understanding of the disclosure, are incorporated in and
constitute a part of this specification, illustrate aspects of the
disclosure and together with the detailed description serve to
explain the principles of the disclosure. No attempt is made to
show structural details of the disclosure in more detail than may
be necessary for a fundamental understanding of the disclosure and
the various ways in which it may be practiced. In the drawings:
[0020] FIG. 1 shows a screw with containment features and a
delivery adapter, according to an aspect of the disclosure;
[0021] FIG. 2 shows the screw of FIG. 1 without the delivery
adapter;
[0022] FIG. 3 shows the delivery adapter of FIG. 1;
[0023] FIG. 4 shows a cutaway view of the assembled screw with
containment features of FIG. 1 attached to a bone, such as a
vertebra;
[0024] FIG. 5A shows an expanding screw, according to an additional
aspect of the disclosure;
[0025] FIG. 5B shows the screw of FIG. 5A after the container has
been filled from a fluid source;
[0026] FIG. 6A shows a cutaway view of the screw of FIG. 5A with
the fins in a straight position and a collapsed container;
[0027] FIG. 6B shows a cutaway view of the screw of FIG. 5A with
the container expanded and the fins in a deformed
configuration;
[0028] FIG. 7A shows a screw that is constructed without a tip;
and
[0029] FIG. 7B shows the distal end of the screw of FIG. 7A with
the container in a collapsed position and the fins in a straight
configuration.
DETAILED DESCRIPTION OF THE DISCLOSURE
[0030] The aspects of the disclosure and the various features and
advantageous details thereof are explained more fully with
reference to the non-limiting aspects and examples that are
described and/or illustrated in the accompanying drawings and
detailed in the following description. It should be noted that the
features illustrated in the drawings are not necessarily drawn to
scale, and features of one aspect may be employed with other
aspects as the skilled artisan would recognize, even if not
explicitly stated herein. Descriptions of well-known components and
processing techniques may be omitted so as to not unnecessarily
obscure the aspects of the disclosure. The examples used herein are
intended merely to facilitate an understanding of ways in which the
disclosure may be practiced and to further enable those of skill in
the art to practice the aspects of the disclosure. Accordingly, the
examples and aspects herein should not be construed as limiting the
scope of the disclosure, which is defined solely by the appended
claims and applicable law. Moreover, it is noted that like
reference numerals represent similar parts throughout the several
views of the drawings.
[0031] FIG. 1 shows a screw with containment features 100,
according to an aspect of the disclosure. The screw with
containment features 100 may include two main components, a screw
200 and a filler delivery adapter 300. As seen in FIG. 2, the screw
200 may be further divided into a distal portion 210 and a proximal
portion 220, connected by a neck 230.
[0032] FIG. 2 further shows the screw 200 according to an aspect of
the disclosure. The distal portion 210 of the screw 200 may include
an expandable container 211 attached to the neck 230. The distal
portion 210 may also include an inner lumen 212 through the
container 211. The lumen 212 may be sealed against the container
211, defining a separate space. The lumen 212 may be connected to a
distal port 213.
[0033] The neck may be connected to the proximal portion 220 of the
screw 200. More specifically, the neck 230 may be connected to a
temporary anchoring device (TAD) 222. The TAD 222 may serve to
temporarily anchor the screw to the bone prior to filling the
container 211 with bone cement or other suitable compound. The TAD
222 may include bone threads or any other device suitable
construction for temporarily anchoring the screw 100 in the bone,
as will be understood by one skilled in the art. The proximal
portion may also include a screw head 221. The screw head 221 may
provide an appropriate interface for connecting the screw 200 to a
rod or other device (not shown). The interface may be, for example,
a polyaxial connector, a monoaxial connector, or a fixed connector.
Other connector types are contemplated and may be used without
departing from the spirit and scope of the specification and the
claims. The proximal portion 220 may further include a receiver 223
for connecting to a delivery adapter.
[0034] FIG. 3 shows a filler delivery adapter 300, according to an
aspect of the disclosure. The delivery adapter 300 may include a
body 304 that interfaces with the screw 200 at the body's distal
end. In particular, the body may include a connector 303 that
removable attaches to the receiver 223 on the screw. The distal end
of the adapter 300 may provide an interface lumen port 301, which
may connect to the lumen of the screw, and an interface filler port
302, which may connect to the filler space of the screw. The
proximal end of the adapter 300 may include a stylet port 307,
which may connect to the lumen of the delivery adapter 300 and, in
turn, the interface lumen port 301. The delivery adapter 300 may
also include a filler arm 305, which may end in a filler port
306.
[0035] FIG. 4 shows a cutaway view of the assembled screw with
containment features 100 attached to a bone 400, such as a
vertebra. In the fully assembled device, the inner lumen 212, lumen
space 231, and inner lumen 308 may form a continuous space, which
may allow, e.g., a straight instrument to be passed through the
screw 100 to the bone on the distal side. Stylet port 307 may
provide access to the lumen on the proximal end, and distal port
213 may provide access to the lumen on the distal end.
[0036] Similarly, filler space 309 and filler space 232 may connect
filler port 306 to container 211. A supply of filler (not shown)
may be connected to filler port 306 and may be provided to the
container 211 under pressure. As the filler enters the container
211, the container 211 may expand and compress cancellous bone in
the surrounding vertebral body or other bone 400. Expansion of the
container 211, which may be accompanied by solidification of the
filler, may create a solid, stable anchor for the screw 100 in
low-quality cancellous bone. The container 211 itself may prevent
extravasation of the filler, further enhancing the stability of the
anchor. In one aspect of the disclosure, the filler may be bone
cement, also known as polymethyl methacrylate (PMMA). Other
suitable compounds may be used, as will be understood by one
skilled in the art, without departing from the spirit and scope of
the specification or the claims.
[0037] The screw with containment features 100 may be temporarily
anchored to the bone 400 with temporary anchoring device (TAD) 222.
For aspects of the disclosure where the TAD includes bone threads,
a pilot hole may be drilled in the bone 400. The pilot hole may be
deep enough into the bone to additionally accommodate neck 230 and
distal portion 210.
[0038] Delivery adapter 300 may attach to screw 200 at an
interface. In certain aspects of the disclosure, the interface may
include male threads on the distal portion of the filler adapter
and corresponding female threads in the proximal portion 220 of the
screw 200. The interface may also align lumen space 231 with inner
lumen 308, as well as filler space 232 with filler space 309. The
corresponding sections may be in fluid communication with one
another but not with the other sections. In other words, lumen
space 231 and inner lumen 308 may form a continuous space that is
not in fluid communication with the continuous space formed by
filler space 232 and filler space 309.
[0039] FIG. 5A shows an expanding screw, according to an additional
aspect of the disclosure. Expanding screws may also be used to
anchor a spinal fusion apparatus in low-quality cancellous bone.
Expanding screw 500 may include a head 501 that may be used with,
e.g., a polyaxial connector, a monoaxial connector, or a fixed
connector for attaching to a rod. Other connector types are
contemplated and may be used without departing from the spirit and
scope of the specification and the claims.
[0040] The head 501 may also provide a receiver 502 for a fluid
source 600. Fluid source 600 may include a reservoir 603, a
connector 602 for attaching to the receiver 502, and a tube 601
connecting the connector 602 to the reservoir 603. Reservoir 603
may provide a fluid under pressure to connector 602. Reservoir 603
may pressurize the fluid through any appropriate means, as will be
understood by one skilled in the art. Examples include a syringe
and a mechanical compressor. The reservoir 603 may be manual,
mechanical, or powered.
[0041] The body 503 of the screw 500 may include one or more bone
threads 504. The bone threads 504 may be continuous with bone
threads 506 associated with a plurality of fins 505, which may be
located distal of the screw body 503. The distal end of screw 500
may terminate in a screw tip 507.
[0042] FIG. 5B shows the screw 500 after container 508 has been
filled from fluid source 600. Connector 602 may be attached to
receiver 502, and a fluid from reservoir 603 may be supplied to
container 508 under pressure. Expansion of container 508 may cause
fins 505 to change shape or deform, assuming a more curved or
spherical shape. Container 508 may push fins 505 outward into,
e.g., cancellous bone inside a vertebral body. Compression of the
cancellous bone may provide fins 505 greater purchase than the fins
505 may have had in non-compressed bone. Bone threads 506, located
on fins 505, may further provide increased purchase.
[0043] Screw 500, and fins 505 in particular, may be constructed
from a material that will retain its altered or expanded shape,
even when pressure is withdrawn from container 508. Accordingly,
container 508 may be filled with, e.g., saline, which may be
drained from the container after the fins 505 have been expanded.
Alternatively, container 508 may be filled with, e.g., bone cement
(PMMA), which would provide an enlarged anchor as well as
additional retention in low-quality bone provided by threads
506.
[0044] FIG. 6A shows a cutaway view of the screw 500 with the fins
505 in a straight position and a collapsed container 508. Connector
602 may be attached to receiver 502 to supply a pressurized fluid
to the screw 500. From the receiver 502, the fluid may travel along
channel 511 to container 508. A fitting 512 may connect the channel
511 to the container 508. A spacer 509 may be disposed within the
container 508. The spacer 509 and/or container 508 may terminate in
a knob 510 located near the tip 507 of the screw 500.
[0045] The spacer 509 may be constructed of a rigid material and
may serve to help keep tip 507 at a fixed distance from screw head
501 while fins 505 are undergoing deformation as a result of the
expansion of the container 508. Without spacer 509 in place,
expansion of the container 508 and deformation of fins 505 may tend
to draw tip 507 and screw head 501 closer together. This
contracting of the screw 500 may weaken the integrity of the
bone-screw interface, thus reducing the strength of the anchor in
the bone. For example, contracting the screw may cause the grooves
of the bone threads to widen, allowing the screw to wiggle or pivot
in the bone.
[0046] FIG. 6B shows a cutaway view of the screw 500 with the
container 508 expanded and the fins 505 in a deformed
configuration. As described above, spacer 509 may keep the screw at
a single length during expansion of the container 508 and
deformation of the fins 505. To accommodate their increased length,
the fins 505 may become thinner, as seen in FIG. 6B.
[0047] Screw 500 may be shipped in a pre-assembled format, with the
expansion apparatus, which may include knob 510, container 508,
fitting 512, channel 511, and receiver 502, already inserted into
the screw or integrally formed therein. Alternatively, the
expansion apparatus may be reusable, which may reduce the cost of
the device. According to this aspect, the expansion apparatus maybe
inserted into the screw housing through an aperture in the screw
head 501. Once the container 508 has been filled, the fluid is
allowed to drain, either naturally or with mechanical assistance,
and the expansion apparatus is removed for use with another
screw.
[0048] FIG. 7A shows a screw 500a that is constructed without a tip
507. As the screw 500a may be inserted into a pre-drilled hole, the
tip 507 may not be necessary to successfully attach the screw to a
bone. Without a tip to hold the fins 505 together at the distal
end, the deformed fins may assume a more convex shape, rather than
the curved or spherical shape seen in previous aspects. Space 509
and knob 510 may still be present in this aspect. Here, they may
serve to control or guide expansion of the container 508.
[0049] FIG. 7B shows the distal end of the screw 500a with the
container in a collapsed position and the fins 505 in a straight
configuration. As screw 500a is open on its distal end, it may be
assembled from the distal end. The expansion apparatus, which may
include knob 510, container 508, fitting 512, channel 511, and
receiver 502, may be inserted through the aperture created by the
removal of the screw tip.
[0050] While the disclosure has been described in terms of
exemplary aspects, those skilled in the art will recognize that the
disclosure can be practiced with modifications in the spirit and
scope of the appended claims. These examples given above are merely
illustrative and are not meant to be an exhaustive list of all
possible designs, aspects, applications or modifications of the
disclosure.
* * * * *