U.S. patent application number 14/635559 was filed with the patent office on 2015-10-01 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 | 20150272630 14/635559 |
Document ID | / |
Family ID | 37912440 |
Filed Date | 2015-10-01 |
United States Patent
Application |
20150272630 |
Kind Code |
A1 |
Biedermann; Lutz ; et
al. |
October 1, 2015 |
BONE ANCHORING DEVICE
Abstract
A bone anchoring device includes a receiving part for receiving
a rod, the receiving part having a first bore coaxial with a
longitudinal axis and a second bore. The bone anchoring device also
includes an anchoring element having a first end for insertion into
the bone and a second end positionable within a second bore, the
second end having a spherically shaped surface portion. The bone
anchoring device further has a locking device provided to the
second bore of the receiving part The locking device protrudes from
an inner wall of the second bore and engages with a recessed
surface portion of the second end of the anchoring element, such
that the anchoring element is pivotable relative to the receiving
part around a single axis of rotation. The locking device may
comprise pins inserted into through holes formed in the receiving
part, which engage with the recessed surface portion of the second
end.
Inventors: |
Biedermann; Lutz;
(VS-Villingen, DE) ; Matthis; Wilfried; (Weisweil,
DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Biedermann Technologies GmbH & Co. KG |
Donaueschingen |
|
DE |
|
|
Assignee: |
Biedermann Technologies GmbH &
Co. KG
|
Family ID: |
37912440 |
Appl. No.: |
14/635559 |
Filed: |
March 2, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13005285 |
Jan 12, 2011 |
8998965 |
|
|
14635559 |
|
|
|
|
11934625 |
Nov 2, 2007 |
7892259 |
|
|
13005285 |
|
|
|
|
60859642 |
Nov 17, 2006 |
|
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Current U.S.
Class: |
606/328 |
Current CPC
Class: |
A61B 17/7038 20130101;
Y10T 29/49826 20150115; A61B 17/7032 20130101; A61B 17/7037
20130101 |
International
Class: |
A61B 17/70 20060101
A61B017/70 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 17, 2006 |
EP |
06023910.0 |
Claims
1. A bone anchoring device, comprising: a receiving part for
receiving a rod, the receiving part having a first bore coaxial
with a longitudinal axis and a second bore, the receiving part
comprising a through hole; an anchoring element having a first end
for insertion into the bone and a second end positionable within
the second bore, the second end comprising a surface having a
spherically shaped surface portion and a portion recessed from the
spherically shaped surface portion; at least one pin provided to
the second bore of the receiving part by insertion into the through
hole, such that the pin protrudes from an inner surface of the
second bore and engages with the portion recessed from the
spherically shaped surface portion of the second end of the
anchoring element, such that the anchoring element is pivotable
relative to the receiving part around a single axis of
rotation.
2. The bone anchoring device according to claim 1, wherein the
through hole extends from a first opening formed in an outer
surface of the receiving part towards a second opening formed in
the inner surface of the second bore, such that the pin protrudes
out of the second opening in the inner surface of the second
bore.
3. The bone anchoring device according to claim 2, wherein the
through hole is arranged such that upon insertion the pin
tangentially engages with the recessed surface portion of the
second end of the anchoring element.
4. The bone anchoring device according to claim 1 wherein two pins
are provided for insertion into respective through holes formed in
the receiving part.
5. The bone anchoring device according to claim 1, wherein the pin
is integrally formed with the receiving part.
6. The bone anchoring device according to claim 1, wherein the pin
is arranged such that the single axis of rotation is perpendicular
relative to the longitudinal axis of the receiving part.
7. (canceled)
8. The bone anchoring device according to claim 1, wherein the
recessed surface portion of the second end of the anchoring element
is substantially flat.
9. The bone anchoring device according to claim 1, wherein a
fixation element cooperates with the receiving part to lock the
anchoring element relative to the receiving part.
10. A method of anchoring a bone anchoring device to a bone, the
method comprising: anchoring a bone anchoring assembly to the bone,
the bone anchoring assembly comprising a receiving part for
receiving a rod and an anchoring element, the receiving part having
a first bore coaxial with a longitudinal axis and a second bore,
the receiving part comprising a through hole; the anchoring element
having a first end for insertion into the bone and a second end
positionable within the second bore, the second end comprising a
surface having a spherically shaped surface portion and a portion
recessed from the spherically shaped surface portion; and inserting
at least one pin in the through hole, the pin protruding from an
inner surface of the second bore and engaging with the portion
recessed from the spherically shaped surface portion of the second
end of the anchoring element to provide pivoting of the anchoring
element relative to the receiving part around a single axis of
rotation.
11. The method of claim 10, further comprising: inserting a rod in
the receiving part; adjusting an angular position of the anchoring
element relative to receiving part around the single axis of
rotation; and securing the anchoring element relative to the
receiving part and securing the rod in the receiving part with at
least one fixation element.
12. (canceled)
13. The method of claim 10, further comprising assembling the bone
anchoring assembly by assembling the anchoring element and the
receiving part.
Description
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application is a continuation of U.S. patent
application Ser. No. 13/005,285, filed Jan. 12, 2011, which is a
continuation of U.S. patent application Ser. No. 11/934,625, filed
Nov. 2, 2007, now U.S. Pat. No. 7,892,259, which claims priority to
and the benefit of U.S. Provisional Patent Application No.
60/859,642, filed Nov. 17, 2006, and which claims priority from
European Patent Application EP 06023910.0, filed Nov. 17, 2006, the
disclosures of which are incorporated herein by reference.
BACKGROUND
[0002] The invention relates to a bone anchoring device which
comprises a receiving part for receiving a rod, an anchoring
element having a first end for insertion into the bone and a second
end held in the receiving part, and a locking device to limit a
pivoting movement of the anchoring element to pivoting around a
single axis.
[0003] Document US 2006/0155277 A1 discloses an anchoring element,
which comprises a retaining means for receiving a rod, the
retaining means having a ring-shaped mount, a fastening element for
anchoring the device in the vertebra, and a securing element which
can be screwed into a thread of the retaining means in order to fix
the fastening element with an angle relative to the retaining
means.
[0004] The fastening element comprises a threaded shank and a
bearing, the latter being provided to achieve a pivotal motion when
being supported by a separate intermediate element, which can be
inserted into the ring-shaped mount of the retaining means. More
specifically, the bearing includes spherical surfaces which engage
with spherical counterparts of the intermediate element. The
bearing further has two flat guiding surfaces formed on opposite
sides thereof, which engage with respectively flat counter surfaces
of the intermediate element.
[0005] The fastening element may perform a rotation movement around
one single axis with respect to the intermediate element. However,
the intermediate element can freely rotate within the mount around
a longitudinal axis of the retaining means. Hence, a polyaxial
adjustment of the fastening element relative to the retaining means
is possible.
[0006] The final fixation is achieved by screwing the securing
element into the thread of the retaining means after the rod is
inserted. As a result thereof, pressure is exerted onto the rod,
which transmits this pressure further to the intermediate element
which then frictionally clamps the bearing. Thus, upon fixation by
the securing element, the degree of free movement is reduced from
polyaxial to fully rigid at the same time.
[0007] For certain applications it is desirable to have a bone
anchoring device which allows an adjustment of the angle between
the bone anchoring element and the receiving part in one single
plane.
[0008] Based on the foregoing, there is a need for a bone anchoring
device, which simplifies handling of an anchoring device and
increases its stability against external forces once the device has
been fixated using a fixation element.
SUMMARY
[0009] The present bone anchoring device is arranged to reduce
rotation of the anchoring element to rotation around one single
axis prior to fixation. For this purpose, a locking device is
provided at an inner wall of the receiving part which engages with
the surface of the head of the anchoring element in order to impede
rotation of the anchoring element around, e.g., a longitudinal axis
of the receiving part. The locking device and the engaging surface
are constructed such as to allow pivotal motion around one single
axis, which in this example may be oriented perpendicular to the
longitudinal axis.
[0010] As a result, there is only one axis of rotation upon
installation of the anchoring devices and the rod. The handling
during installation may thus be simplified. Limiting the pivotal
movement of the anchoring devices with regard to the receiving part
to just one single axis serves to simplify the handling of the
parts of the anchoring device during application to the bones and
increases the stability of the installed parts with respect to
external forces.
[0011] Further features and advantages of the bone anchoring device
will become apparent and will be best understood by reference of
the following detailed description taken in conjunction with the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 shows a perspective exploded view of a bone anchoring
device according to an embodiment prior to assembly;
[0013] FIG. 2 shows a perspective exploded view of the bone
anchoring device according to FIG. 1, but after partial
assembly;
[0014] FIG. 3 shows a partial sectional view of the bone anchoring
device according to the partially assembled state of FIG. 2, with a
sectional plane defined by a longitudinal axis and a pivotal
axis;
[0015] FIG. 4 shows a perspective view of an anchoring element;
[0016] FIG. 5 shows a top view of a head of the anchoring element
shown in FIG. 4;
[0017] FIG. 6a shows a side view of the anchoring element shown in
FIG. 4 with flat guiding surface portions seen in profile;
[0018] FIG. 6b shows a side view of the anchoring element shown in
FIG. 6a, but with flat guiding surface portions oriented towards an
observer (90 degrees rotated);
[0019] FIG. 7a shows a side view of an alternative embodiment of a
head with flat guiding surfaces being inclined with respect to an
axis of a shank of an anchoring element;
[0020] FIG. 7b shows a side view of the anchoring element shown in
FIG. 7a, but with one of the flat guiding surfaces oriented toward
an observer (90 degrees rotated);
[0021] FIG. 7c shows a side view of the anchoring element shown in
FIG. 7b, but with the other of the flat guiding surfaces oriented
toward the observer;
[0022] FIG. 8 shows the arrangement of through holes in a
cross-sectional profile through a horizontal plane labeled as 42 in
FIG. 3, the plane containing the rotational axis;
[0023] FIG. 9 shows an alternative embodiment of an arrangement of
through holes;
[0024] FIG. 10 shows a partial sectional view of the bone anchoring
device with an alternative embodiment of a pin having a
semi-circular cross-section;
[0025] FIG. 11a shows a partial sectional view of the anchoring
element and a pin having a circular cross-section according to the
embodiment of FIG. 3;
[0026] FIG. 11b shows a partial sectional view of the anchoring
element and the pin according to the embodiment of FIG. 10;
[0027] FIG. 11c shows a partial sectional view of the anchoring
element with an alternative embodiment of a pin having a
rectangular cross-section;
[0028] FIG. 11d shows a partial sectional view of the anchoring
element and a semi-circular pin in a through hole of the bone
anchoring device having an alternative arrangement;
[0029] FIG. 11e shows a partial sectional view of the anchoring
element and the pin according to FIG. 11d when the pin is rotated
within the through hole;
[0030] FIG. 11f shows a partial sectional view of the anchoring
element with a further alternative embodiment of a pin having a
square profile;
[0031] FIG. 11g shows a partial sectional view of the anchoring
element with a further alternative embodiment of a pin having an
elliptical cross-section;
[0032] FIG. 12a shows an perspective exploded view of an embodiment
wherein the through holes are arranged in a longitudinal direction
with respect to the receiving part;
[0033] FIG. 12b shows a partial sectional view of the embodiment
according to FIG. 12a;
[0034] FIG. 13a shows partial sectional view of a bone anchoring
device according to an embodiment wherein only one through hole is
formed in a receiving part;
[0035] FIG. 13b shows a top view of an anchoring element according
to the embodiment of FIG. 13a;
[0036] FIG. 13c shows a side view of the anchoring element of FIG.
13b;
[0037] FIG. 13d shows a side view of the anchoring element shown in
FIG. 13c, but with a flat guiding surface oriented toward an
observer (90 degrees rotated).
DETAILED DESCRIPTION
[0038] FIGS. 1 to 3 show in a perspective view a first embodiment
of a bone anchoring device, wherein FIG. 1 reveals a situation
prior to assembly, FIG. 2 shows details after assembly, and FIG. 3
shows a partly cross sectional profile of the embodiment
illustrated in FIGS. 1 and 2 without rod and fixation element.
[0039] The bone anchoring device includes a receiving part 1 which
has a first end 2 and a second end 3 opposite to the first end. The
two ends extend perpendicular to a longitudinal axis 4. Coaxially
formed with the longitudinal axis 4, a bore 5 is provided which
extends from the first end 2 to a predetermined distance from the
second end 3. At the second end 3 an opening or second bore 6 is
provided, the diameter of which is smaller than the diameter of the
bore 5. The coaxial bore 5 tapers towards the opening 6 in a
section 7 which can be for example spherically, conically or
otherwise shaped.
[0040] The receiving part 1 further has a substantially U-shaped
recess 8 which starts from the first end 2 and extends in the
direction of the second end 3 to a predetermined distance from said
second end 3. By means of the U-shaped recess 8 two free legs 9, 10
are formed extending towards the first end 2.
[0041] Adjacent to the first end 2, the receiving part 1 includes
an internal thread 11 on said legs 9, 10. The U-shaped recess 8
serves for receiving a rod 12 by which several bone anchoring
devices can be connected. A screw 30 cooperating with the internal
thread is used as a fixation element. The U-shaped recess 8 further
defines an axis 31 along which the rod 12 is oriented upon
installation in the U-shaped recess 8. In this specific embodiment,
axis 31 is perpendicular to the longitudinal axis 4.
[0042] The bone anchoring device further has a bone anchoring
element 13 which includes a shank 14 with a bone thread and a head
15 at one end. It is noted that the shank 14 of the anchoring
element 13 may not necessarily be threaded and may include other
forms suited to apply the anchoring device.
[0043] As shown in more detail in FIGS. 4 to 6, the head 15 has a
spherical surface portion 16 with the center M (not shown) of a
respective sphere 36 lying in the center of the head 15. The head
15 further has two substantially flat surface portions 35a, 35b
recessed from an ideal sphere as defined by spherical surface
portion 16. The flat surface portions are positioned on opposite
sides of the head 15 and are oriented parallel to each other.
[0044] On the side opposite to the shank 14, the head 15 may
include a flat surface 18. A recess 19 for engagement with a
screwing-in tool can be provided in the flat surface 18. The head
15 rests in the section 7 of the receiving part 1 which thus forms
a seat for the head 15.
[0045] A pressure element 20 is provided for acting onto the head
15. The pressure element 20 is substantially cylindrically-shaped
and comprises a first end 21 and a second end 22. The outer
diameter of the pressure element 20 is slightly smaller than the
inner diameter of the bore 5 of the receiving part 1 so that the
pressure element 20 can be inserted into the receiving part 1 and
can slide within the bore 5. Adjacent to the first end 21 the
pressure element 20 comprises a cylindrical segment-shaped recess
23, the size of which is such that the rod 12 fits in the recess
23.
[0046] Adjacent to the second end 22 the pressure element 20
includes a spherically shaped inner surface. The radius of the
sphere corresponds to that of the head 15. The pressure element 20
further has a coaxial bore 28 for allowing access for a screwing in
tool to the recess 19 in the head 15. The pressure element 20 can
further be secured against falling out of the receiving part 1 once
it has been inserted, or against rotation within the receiving part
1, for example by means of crimp bores 27 or means exerting a
similar function. However, the bone anchoring device is not limited
thereto.
[0047] The receiving part 1 according to this embodiment further
includes two through holes 34 each receiving a pin 33. The diameter
of the pins 33 corresponds to that of the through holes 34. The
through holes 34 are located on opposite sides in the region of the
7 and traverse the body of receiving part 1. The through holes 34
also traverse an inner space as defined by the seat 7 of the
receiving part 1, which becomes visible from a cross-sectional
profile of a plane perpendicular to the longitudinal axis 4 as
shown in FIG. 8. More specifically, the through holes 34 are open
towards the inner wall of the seat 7 of the receiving part 1.
Consequently, the diameter of the space defined by the seat 7 is
reduced, when pins 33 are inserted into the through holes 34. In
other words the pins 33 protrude from the inner surface of the seat
7 when residing within the through holes 34.
[0048] Once being inserted into the through holes 34 of the body of
the receiving part 1, the pins 33 engage with the flat surface
portions 35a, 35b of the head 15 of the anchoring element 13. As a
result thereof, the head 15 cannot be rotated within a plane
perpendicular to the longitudinal axis 4 due to the presence of the
pins 33, as it is illustrated in FIG. 8. However, as the flat
surfaces 35a, 35b serve as guiding surfaces, a pivotal motion
around a rotation axis 46 as shown in FIG. 2 is retained.
[0049] In this embodiment, the U-shaped recess 8 is aligned with
the direction of the through holes 34, such that the rotation axis
46 is perpendicular to the longitudinal axis 4 and to the rod axis
31. Accordingly, rotation of the anchoring element 13 is enabled in
a plane defined by the longitudinal axis 4 and the axis 31 (see
FIG. 2). It is noted, however, that it is also within the scope of
the invention to orient the through holes (and thus the pins upon
insertion) perpendicular to the rod axis. Rotation is then enabled
in a plane perpendicular to the rod direction.
[0050] It becomes clear to the person skilled in the art, that any
direction of the through holes 34 as formed in the receiving part 1
may be constructed according the specific needs. FIG. 9 shows
another embodiment, wherein multiple through holes 34a, 34b are
formed perpendicular to and cross each other. The pin may be
inserted either into through hole 34a, or alternatively into
through hole 34b. Only one through hole 34a, 34b per direction is
shown. Using the bone anchoring device according to this
embodiment, the surgeon may in-situ decide which rotational axis is
presently preferred to achieve stability.
[0051] According to a further embodiment illustrated in FIGS. 7a-c,
the orientation of the surface normal 41 of the flat guiding
surfaces 35c, 35d is inclined with respect to a plane defined by
the top surface 18 of the anchoring element 13. As a result
inclined angles a of the threaded shafts 14 with respect to the
longitudinal axis 4 of the receiving part 1 may be accomplished. A
set of anchoring elements with different inclination angles
.alpha.=0.degree., 5.degree., 10.degree., 15.degree., etc.,
respectively, may be supplied for example, from which the surgeon
may choose according to the situation. It is noted that the
rotation axis 46 is retained in this embodiment.
[0052] It is noted that the whole device including the pins is
preferably made of a biocompatible material, for example titanium,
titanium alloy or stainless steel, etc.
[0053] The bone anchoring device described in the present
embodiments may be assembled upon the instance of actually carrying
out surgery. However, the device may as well be preassembled. In
such a preassembled condition, the anchoring element is screwed
into the bone.
[0054] In the specific embodiments detailed herein pivoting within
a single plane is accomplished by means of the pins 33 acting onto
the flat guiding surfaces 35a-d of head 15, which allows pivoting
around rotation axis 46, but prevents pivoting around other axes 4,
31. Therefore, an adjustment of the position of the receiving part
1 with respect to the anchoring element 13 within a plane that
includes the rod axis is possible, whereas an adjustment in a
direction perpendicular to the rod axis is blocked according to the
present embodiments.
[0055] After adjustment of the position of the receiving part 1 the
rod 12 is inserted and the inner screw 30 is screwed-in between the
legs 9, 10 and tightened to exert a pressure onto the rod 12. The
rod 12 transmits the pressure to the pressure element, which itself
exerts a pressure onto the head 15 to lock it in its final
position.
[0056] FIGS. 10 and 11a-11g show an outline of alternative
embodiments for the pins 33. In the previous embodiments, the pins
33a are shown to have a circular cross-section. The embodiment of
FIG. 10, however, illustrates that the same effect may be achieved
using pins 33b having a semi-circular cross-section. As shown in
FIGS. 11a-11g, a square or rectangular profiled pin 33c, 33e or an
elliptical pin 33f, etc. are also possible. Preferred are
cylindrical pins for the reason of easier manufacturing. However,
flat shapes are also advantageous as these provide a particularly
tight contact to the flat surfaces 35a, 35b.
[0057] With regard to a semi-circular pin 33d further illustrated
in the bottom section of FIG. 10b, the respective through hole may
be arranged such that the pins 33d only protrude from the inner
surface of the bore 6 or tapered section 7, if the pin 33d is
rotated within the bore of the through hole 34. A fixing means (not
shown) may be actuated such that this position of the pin 33d
within the through hole 34 is retained. An advantage arises as upon
spinal surgery the pins may already be inserted prior to applying
the anchoring element 13 to the bone. The surgeon merely has to
actuate the pin 33d by rotating it within the through hole 34, when
a reduction of pivoting movement is desired.
[0058] In an alternate embodiment, the fixation element 30 may be
composed of an inner member and an outer member (not shown). The
outer member is threaded for screwing it into internal thread 11 of
the receiving part. A bottom surface of the outer member of the
fixation element 30 then exerts a pressure force onto the pressure
element 20 in order to fix the head 15. The inner member of the
fixation element 30 may be screwed into a threaded bore within the
outer member and interacts with the rod 12. It thus becomes
possible to fix the rod 12 and the anchoring element 13 separately
by means of the two members of the fixation element 30.
[0059] According to one embodiment pins may be inserted into
through holes formed in the receiving part from outside the
receiving part such that the pins cross the spherical portion being
used as a bearing for the head of the anchoring element and the
pins engage with the recessed surface of the head. Accordingly, the
surgeon may fix the degree of rotation depending on the situation.
Without the pins, the anchoring element can be pivoted in any
direction.
[0060] In a modification of the application the receiving part 1
can be used without the pins and with an anchoring element having a
spherically shaped head. Hence, the surgeon can decide depending on
the actual situation at the operation side whether a monoplanar or
a polyaxial anchoring device is to be implanted using one and the
same type of receiving part 1.
[0061] It is noted that the seat 7 of the receiving part 1 may also
be of a conical or any other shape, wherein the same details of
construction with regard to the locking device and/or the pins may
be applied as described above. Further, the locking device may
alternatively be integrally formed with the inner surface of the
second bore.
[0062] The pins 33 may be inserted into through holes 34, which are
oriented within a horizontal plane with regard to the receiving
part 1 as shown, e.g., in FIG. 1. However, the invention is not
restricted to that specific embodiment. An alternate embodiment
shown in FIG. 12a-12b indicates that the through holes 34 may
equivalently be arranged in a longitudinal direction with respect
to the receiving part 1. The pins 33 are then inserted into the
through holes 34 from a bottom side of the receiving part. Other
directions of the through holes 34 than horizontal or longitudinal
are possible as well.
[0063] A further embodiment is shown in FIG. 13a-13d. According to
this embodiment only one through hole 34 is provided to the
receiving part 1. The supply of only one through hole and one pin
to be inserted into the through hole may provide sufficient
stability when locking the anchoring element 13. In this case, the
head 15 of the anchoring element 13 may similarly be provided with
only one flat surface 35a (FIGS. 13b-13d).
* * * * *