U.S. patent application number 14/147846 was filed with the patent office on 2014-08-07 for bone anchoring device.
This patent application is currently assigned to Biedermann Technologies GmbH & Co. KG. The applicant listed for this patent is Biedermann Technologies GmbH & Co. KG. Invention is credited to Lutz Biedermann, Wilfried Matthis.
Application Number | 20140222079 14/147846 |
Document ID | / |
Family ID | 36933600 |
Filed Date | 2014-08-07 |
United States Patent
Application |
20140222079 |
Kind Code |
A1 |
Matthis; Wilfried ; et
al. |
August 7, 2014 |
BONE ANCHORING DEVICE
Abstract
A bone anchoring device includes a bone anchoring element having
a shaft to be anchored in the bone and a head, a receiving part for
receiving a rod to be connected to the bone anchoring element, and
a pressure member acting onto the head to lock the position of the
head relative to the receiving part, the receiving part is formed
in one piece and includes an open first bore with a first bore
axis, a recess shaped and sized to receive a rod having a
longitudinal axis, and a second bore having a second bore axis. The
second bore is in communication with the first bore and is sized to
receive the head with a part of the shaft extending through the
second bore. The second bore axis includes an angle of
approximately 90.degree. with a plane defined by the first bore
axis and the longitudinal axis of the rod.
Inventors: |
Matthis; Wilfried;
(Weisweil, DE) ; Biedermann; Lutz; (VS-Villingen,
DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Biedermann Technologies GmbH & Co. KG |
Donaueschingen |
|
DE |
|
|
Assignee: |
Biedermann Technologies GmbH &
Co. KG
Donaueschingen
DE
|
Family ID: |
36933600 |
Appl. No.: |
14/147846 |
Filed: |
January 6, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11697220 |
Apr 5, 2007 |
8641737 |
|
|
14147846 |
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60790084 |
Apr 6, 2006 |
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Current U.S.
Class: |
606/267 |
Current CPC
Class: |
A61B 17/7055 20130101;
A61B 17/7032 20130101; A61B 17/7011 20130101; A61B 17/7034
20130101; A61B 17/7038 20130101; A61B 17/7037 20130101 |
Class at
Publication: |
606/267 |
International
Class: |
A61B 17/70 20060101
A61B017/70 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 6, 2006 |
EP |
06007324.4 |
Claims
1-17. (canceled)
18. A bone anchoring device comprising: a bone anchoring element
having a shaft and a head; a rod having a longitudinal axis; and a
receiving part configured to connect to the bone anchoring element,
the receiving part comprising: an open first bore with a first bore
axis, the first bore defining a recess configured to receive the
rod; a second bore having a second bore axis, the second bore being
in communication with the first bore and configured to receive the
head with a part of the shaft extending through the second bore;
wherein the second bore axis lies in a different plane than a plane
defined by the first bore axis and the longitudinal axis of the
rod.
19. The bone anchoring device according to claim 18, further
comprising a pressure member acting onto the head to lock the
position of the head relative to the receiving part.
20-23. (canceled)
Description
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application is a continuation of U.S. patent
application Ser. No. 11/697,220, filed Apr. 5, 2007, which claims
the benefit of U.S. Provisional Patent Application Ser. No.
60/790,084, filed Apr. 6, 2006, and claims priority from European
Patent Application EP06007324.4, filed Apr. 6, 2006, the entire
disclosures of which are incorporated herein by reference.
BACKGROUND
[0002] The invention relates to a bone anchoring device in
particular to a bone anchoring device which can be used for
stabilization of the spine in the sacro-iliac region.
[0003] Stabilization of the spine in the sacro-iliac region
requires in certain constellations that the bone screw which is to
be connected with the spinal stabilization rod is screwed laterally
into the bone.
[0004] U.S. Pat. No. 6,981,973 discloses a low profile vertebral
alignment/fixation assembly which comprises a hemispherical headed
pedicel screw disposed within a slotted coupling unit designed to
allow angular adjustment of the pedicle screw up to 90.degree. and
which may be locked into position via a single internal locking nut
once a rod has been inserted into the slotted coupling unit. The
nut has an engagement portion designed to engage the rod. The head
of the screw is locked by the action of the rod pressing onto the
head. The assembly can be anchored in the ileum bone with the screw
aligned at a 90.degree. angle with reference to the coupling
unit.
[0005] US 2005/0159750 A1 discloses a bone anchor assembly
comprising a bone anchor and a receiving member for receiving a
spinal rod. The bone anchor can be adjusted in the receiving member
such that the longitudinal axis of the bone anchor is at an angle
of 0.degree. to 90.degree. relative to the receiving member in a
plane which contains the longitudinal axis of the spinal rod. A
main application of this anchor assembly is the stabilization of
the cervical spine where it can be necessary to pivot the bone
anchors out of an alignment to avoid interference due to their
close proximity.
[0006] US 2005/0154391 A1 discloses a bone anchor assembly
comprising a bone anchor and a receiving member to receive a spinal
rod. The receiving member has a first section and a second section
which is coupled to the bone anchor. The second section is movably
connected to the first section. The bone anchor may be adjusted
such that the longitudinal axis of the bone anchor is at an angle
of 0.degree. to 90.degree. relative to the receiver member.
[0007] U.S. Pat. No. 6,736,820 discloses a bone screw having a
screw member with a threaded section and a head and a receiving
part for receiving a rod to be connected to the bone screw. The
receiving part has an open first bore and a substantially U-shaped
cross-section to receive the rod and a second bore on the opposite
end with a seat for the head. In order that the screw member can be
pivoted to at least one side by an enlarged angle, the edge
bounding the free end of the second bore is of asymmetric
construction.
[0008] US 2003/0055426 A1 discloses a biased angulation bone
fixation assembly including and anchoring element and a coupling
element having a first bore coaxial with a first longitudinal axis
and a second bore coaxial with a second longitudinal axis wherein
said first and second longitudinal axes are transverse to one
another. The coupling element also includes rod receiving openings
for receiving a spinal rod.
[0009] Based on the above, there is a need to provide an improved
bone anchoring device which allows a lateral fixation of the bone
anchoring element in the bone, e.g., at an angle of at least
90.degree. relative to the receiving part in a plane perpendicular
to the longitudinal axis of the spinal rod which is suitable for
use in the sacro-iliac region of the spine.
SUMMARY
[0010] The bone anchoring element of the disclosed bone anchoring
device is compact with few parts and provides a reliable
fixation.
[0011] The bottom of the receiver part and the surface of the
pressure element which contacts the head of the bone anchoring
element preferably have a spherical surface which correspond to the
spherical section of the surface of the head. This provides for a
balanced clamping stress to clamp the head. As a result, the
clamping stress onto the head can be reduced.
[0012] The bone anchoring device has a further advantage in that it
allows to orient the screw relative to the receiving part at an
angle which is greater than 90.degree..
[0013] Further features and advantages of the invention will become
apparent and will be best understood by reference to the following
detailed description of embodiments taken in conjunction with the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 shows an exploded perspective view of a first
embodiment of the bone anchoring device.
[0015] FIG. 2 shows a sectional view of the bone anchoring device
of FIG. 1 in an assembled state.
[0016] FIG. 3 shows a side view of the bone anchoring device of
FIG. 1 in an assembled state.
[0017] FIG. 4 shows a top view of a spinal stabilization system
which includes the bone anchoring device according to the
invention.
[0018] FIG. 5 shows an exploded cross-sectional view of the bone
anchoring device according to a second embodiment.
[0019] FIGS. 6a to 6c show cross-sectional views of different steps
of assembly of the bone anchoring device according to FIG. 5.
[0020] FIG. 7 shows a side view of the bone anchoring device
according to FIG. 5 in an assembled state.
[0021] FIG. 8 shows a side view rotated by 180.degree. of the bone
anchoring device according to FIG. 5 in an assemble state.
[0022] FIG. 9 is a sectional view of a bone anchoring device
according to a third embodiment.
[0023] FIG. 10 is a rear side view showing the bone anchoring
device of the third embodiment.
[0024] FIG. 11 is a perspective view of the bone anchoring element
of the third embodiment.
DETAILED DESCRIPTION
[0025] The bone anchoring device 1 according to a first embodiment
shown in FIGS. 1 to 3 comprises a screw member 2 having a threaded
shaft 3 and a head 4 which is preferably shaped as a spherical
segment, and a receiving part 5 for receiving a rod 100 to be
connected with the screw member 2. The head 4 has a recess 4' at
its free end for engagement with a screwing-in tool. The receiving
part 5 has a first end 6 and an opposite second end 7 and first
bore 8 being open to the first end 6 and defining a first bore axis
9. The receiving part 5 further has a substantially U-shaped recess
10 defining two free legs for receiving the rod 100 in-between. An
internal thread 11 is provided at the legs.
[0026] The receiving part 5 further comprises a second bore 12
having a second bore axis 13, the second bore 12 being in
communication with the first bore 8 and being open to a lateral
side of the receiving part 5 between the first end 6 and the second
end 7. The second bore axis 13 intersects the first bore axis 9 at
an angle .alpha. of approximately 90.degree..+-.12.degree.,
preferably slightly less than 90.degree., for example, 85.degree..
The angle .alpha. is measured from the bottom of the receiving part
5. The diameter of the second bore 12 is smaller than the largest
diameter of the head 4 but larger than the diameter of the threaded
shaft 3 of the screw member 2. Adjacent to the outer wall of the
receiving part 5 the second bore 12 comprises a section 14 with an
increasing diameter in the direction of the outer wall. The
diameter may increase, for example, in the shape of a conical
section widening towards the outer wall. At the bottom of the
receiving part 5 at the second end 7 a seat 15 is provided in which
a part of the head 4 can rest. Preferably, the seat 15 has a
spherical shape which is adapted to the spherical outer surface of
the head 4.
[0027] Furthermore, the receiving part 5 comprises a third bore 16
having a third bore axis 17, the third bore 16 being in
communication with the first bore 8 and being open to the lateral
side of the receiving part 5 between the first end 6 and the second
end 7 which is opposite to the second bore 12. Preferably, the
third bore axis 17 is coaxial with the second bore axis 13 of the
second bore 12. The diameter of the third bore 17 is larger than
the largest diameter of the head 4 and thus larger than the
diameter of the threaded shaft 3. Since the third bore 16 is in
communication with the first bore 8 it is also in communication
with the second bore 12.
[0028] The bone anchoring device 1 further comprises a pressure
element 20 which has a substantially cylindrical outer surface with
a largest diameter which is smaller than the inner diameter of the
first bore 8 to such an extent that the pressure element 20 can
move within the first bore 8. On its side facing the first end 7
the pressure element 20 comprises a spherical recess 21 the shape
of which is adapted to the spherical surface of the head 4. On its
opposite side the pressure element 20 comprises a cylindrical
recess shaped and sized to receive a part of the rod 100 when the
rod 100 is inserted. Further, the pressure element 20 comprises, on
opposite sides of the cylinder axis of the cylindrical recess 22 at
the end which has the spherical recess 22, cut-outs 23 for allowing
a pivoting of the threaded shaft 3 when the head 4 of the screw
member 2 is partly encompassed by the pressure element 20. As can
be seen in FIG. 3 the cut-outs 23 have such a size so as to allow
access to the recess 4' of the head 4 of the screw member 2 even if
the bone anchoring device 1 is in an assembled state.
[0029] The bone anchoring device 1 also comprises a locking screw
25 with an external thread cooperating with the internal thread 11
of the receiving part 5.
[0030] The dimension of the pressure element 20 is such that in an
assembled state when the screw member 2 is inserted into the
receiving part 5 and the rod 100 is inserted into the pressure
element 20 and when the locking screw 25 is not yet tightened, the
bottom of the cylindrical recess 22 of the pressure element 20
projects above the bottom of the U-shaped recess of the receiving
part 5.
[0031] The bone anchoring device 1 is assembled by first
introducing the threaded shaft 3 through the third bore 16 and the
second bore 12 which is in communication with the third bore 16
until the head 4 rests in the seat 15. Then the pressure element 20
is moved so as to engage the part of the spherical segment head 4
with its spherical recess 21. The bone anchoring device 1 may be
preassembled in such a manner before it is used in surgery.
[0032] In use, first, the screw member 2, which is preassembled
with the receiving part 5 and the pressure element 20, is screwed
into the bone by engaging the recess 4' of the head 4 with a
screwing-in tool reaching through the third bore 16. The first bore
axis 9 encloses with the longitudinal axis of the screw member 2 an
angle which can be approximately at least .alpha..+-.10.degree.
which depends on the size of the diameter of the second bore 12 and
the size of the section 14 having the increasing diameter.
Similarly, the longitudinal axis of the screw member 2 can include
an angle of .+-.10.degree. with an axis which is perpendicular to
the first bore axis 9 and perpendicular to the longitudinal axis L
of the rod 100. Hence, the screw member 2 can be pivoted in an
angular range of .+-.10.degree. within a cone around the second
bore axis 13, the angular range depending on the size of the second
bore 12 and of the section 14.
[0033] Once the rod 100 is inserted and the angular position
between the screw member 2 and the receiving part 5 adjusted, the
locking screw 25 is screwed-in which presses onto the rod 100 to
fix the rod 100 and simultaneously presses onto the pressure member
20 via the rod 100 to lock the head 4 of the screw 2 in its
position.
[0034] FIG. 4 shows the application of the bone anchoring device I
in a stabilization system in the sacro-iliac region of the spine. A
plurality of known anchoring devices 101 are each connected with a
rod 100. The rods 100 of the stabilization system extend into the
region of the sacrum 50. Bone anchoring devices 1 according to the
invention are used for sacro-iliac fixation. For this purpose, it
is necessary that the screw members 2 extend at an angle of
approximately 90.degree. from the plane which comprises the
longitudinal rod axis L and the first bore axis 9. The screw member
2 can pivot with respect to the second bore axis within an angular
range of .+-.10.degree. as described above.
[0035] FIGS. 5 to 8 show a second embodiment of the bone anchoring
device. The bone anchoring device of the second embodiment differs
from the bone anchoring device of the first embodiment in the
construction of the second and third bore of the receiving part.
All other parts are identical to the first embodiment and have the
same reference numerals as in the first embodiment. A description
thereof is not repeated. The receiving part 500 comprises a second
bore 120 which is in communication with the first bore 8 and which
defines a second bore axis 130. As in the first embodiment the
second bore 120 is open to the lateral side of the receiving part
500 and the second bore axis 130 extends at an angle of
approximately 90.degree. from the plane defined by the longitudinal
axis of the rod 100 and the first bore axis 9. The diameter of the
second bore 120 is larger than the largest diameter of the head 4
of the screw member 2 such that the head 4 of the screw member 2
can be introduced into the receiving part 500 through the second
bore 120 until the head 4 rests in the seat 15 on the bottom of the
receiving part 500. On the side opposite to the second bore 120 a
third bore 160 is provided which is in communication with the first
bore 8 and which defines a third bore axis 170. The third bore axis
170 is preferably coaxial with the second bore axis 130. The third
bore 160 is open to the lateral side and has a diameter which is at
least as large so that a screwing-in tool can be introduced for
engagement with the recess 4' of the head 4 but the diameter is
smaller than the largest diameter of the head 4 so that the screw
member 2 can not escape through the third bore 160. Since the third
bore 160 is in communication with the first bore 8 it is also in
communication with the second bore 120.
[0036] The bone anchoring device 1 is preassembled as shown in
FIGS. 6a and 6b in that the screw member 2 is introduced with its
head 4 through the second bore 120 until the head 4 rests in the
seat 15. Then, in use, the screw member 2 is screwed into the bone
by introducing a screwing-in tool which engages the recess 4' of
the head through the third bore 160. Thereafter, the angular
position of the screw member 2 relative to the receiving part 500
is adjusted, the rod is inserted and the device is locked by
screwing-in the screw 25.
[0037] In an alternative use, the screw member 2 can be screwed
into the bone and the receiving part 500 can be later on connected
to the screw member 2 by introducing the head of the screw member
through the second bore 120 into the receiving part 500.
[0038] FIGS. 9 to 11 show a bone anchoring device according to a
third embodiment. The bone anchoring device differs from the bone
anchoring device according to the first embodiment only in the
design of the bone anchoring element. The receiving part 5 is
identical. The bone anchoring element 200 comprises a threaded
shaft 3 and a head 400. On its side opposite to the threaded shaft
3 the head 400 comprises a hexagonally-shaped projection 401 for
engagement with a tool which can be introduced through the third
bore 16. This has the advantage that the head 400 can be made as a
solid sphere or spherical segment without a recess. The projection
401 can have any shape which is appropriate for engagement with a
tool. In a further modification the projection 401 itself has a
recess for engagements with a tool.
[0039] Modifications of the invention are possible, for example, in
the case of the second embodiment when the screw member 2 is
screwed-in into the bone first, and thereafter connected to the
receiving part 500, it may be possible to omit the third bore 160.
The size of the second bore may vary in order to allow pivoting of
the bone screw member relative to the receiving part in an enlarged
or in a reduced angular range. The cut outs 23 at the pressure
element may be omitted, as long as it is possible to access the
screw head with a tool. Alternatively, only one cut out is
provided.
[0040] For the purpose of preassembly, it is possible to connect
the pressure element 20 with the receiving part via crimp
bores.
[0041] The seat 15 needs not to have a spherical shape, it can have
another shape or be flat. For the closure mechanism other
mechanisms than those using a single locking screw are possible.
For example, a locking assembly consisting of a rod locking screw
and a head locking nut-like element are possible. A pressure
element in this case has upstanding legs projecting above the rod
so that the pressure element can be pressed down independently of
the rod.
[0042] The shaft need not to be threaded but can have any other
shape and structure which allows retention in the bone. The
pressure element can also be shaped as a flat disc.
[0043] While a particular form of the disclosure has been
illustrated and described, it will be apparent that various
modifications can be made without departing from the spirit and
scope of the disclosure. Accordingly, it is not intended that the
disclosure be limited, except as by the appended claims.
* * * * *