U.S. patent application number 12/110785 was filed with the patent office on 2008-11-06 for fixation device, combination of a fixation device with an elongate element, arrangment with such a combination and osteosynthesis set.
This patent application is currently assigned to MEDARTIS AG. Invention is credited to Joanna Norstrom, Jurgen Schonhardt, Thomas Tribelhorn, Hermann Zeuner.
Application Number | 20080275510 12/110785 |
Document ID | / |
Family ID | 38541920 |
Filed Date | 2008-11-06 |
United States Patent
Application |
20080275510 |
Kind Code |
A1 |
Schonhardt; Jurgen ; et
al. |
November 6, 2008 |
Fixation Device, Combination of a Fixation Device with an Elongate
Element, Arrangment with Such a Combination and Osteosynthesis
Set
Abstract
A fixation device is used to fix an elongate element, in
particular a wire, in an opening of a retaining structure, in
particular of an implant plate. The fixation device has a main
body. The main body is provided with a bore for receiving the
elongate element. The main body is radially deformable in a clamp
area, such that the diameter of the bore can be reduced. The main
body has an outer contour which is designed in such a way that,
when the fixation device is inserted into the opening of the
retaining structure, the clamp area is deformed such that the
elongate element is clamped securely in the bore.
Inventors: |
Schonhardt; Jurgen;
(Rheinfelden, DE) ; Tribelhorn; Thomas; (Holstein,
CH) ; Zeuner; Hermann; (Freiburg, DE) ;
Norstrom; Joanna; (Basel, CH) |
Correspondence
Address: |
SHOEMAKER AND MATTARE, LTD
10 POST OFFICE ROAD - SUITE 110
SILVER SPRING
MD
20910
US
|
Assignee: |
MEDARTIS AG
Basel
CH
|
Family ID: |
38541920 |
Appl. No.: |
12/110785 |
Filed: |
April 28, 2008 |
Current U.S.
Class: |
606/286 ;
606/103; 606/305 |
Current CPC
Class: |
A61B 2017/8655 20130101;
A61B 17/62 20130101; A61B 17/848 20130101; A61B 90/50 20160201;
A61B 2017/868 20130101; A61B 17/861 20130101; A61B 17/8047
20130101; A61B 2017/3405 20130101; A61B 17/864 20130101; A61B
17/683 20130101; A61B 17/8052 20130101 |
Class at
Publication: |
606/286 ;
606/103; 606/305 |
International
Class: |
A61B 17/84 20060101
A61B017/84; A61B 17/80 20060101 A61B017/80 |
Foreign Application Data
Date |
Code |
Application Number |
May 3, 2007 |
EP |
07107464.5 |
Claims
1. Fixation device for fixing an elongate element in a seat of a
retaining structure, with a main body, which has an opening for
receiving the elongate element, wherein the main body, at least in
a clamp area, is radially deformable relative to the elongate
element, such that the dimension of the opening can be reduced, the
main body having an outer contour which is designed in such a way
that, when the fixation device is inserted into the seat, the clamp
area can be deformed such that the elongate element can be clamped
securely in the opening.
2. Fixation device according to claim 1, wherein the fixation
device is provided, in the clamp area, with at least one slit,
which extends at least partially in the direction of the opening
and ends at least partially in the latter.
3. Fixation device according to claim 1, wherein, in the clamp
area, the fixation device is provided on the outer contour with at
least one clamp surface that at least partially reduces radially in
the circumferential direction.
4. Fixation device according to claim 1, wherein the fixation
device has a main body which, seen in the longitudinal direction,
has at least partially a rounded outer contour.
5. Fixation device according claim 1, wherein the fixation device
is designed in the clamp area as a screw head.
6. Fixation device according to claim 5, wherein the fixation
device has a design selected from the group consisting of a screw
with a screw shank having a screw thread, and a pin with a shank
without a screw thread.
7. Fixation device according to claim 5, wherein the screw head is
provided with an extension for applying a torque to the fixation
device.
8. Fixation device according to claim 2, wherein the slit is
arranged at least in the clamp area and at most along the entire
length of the main body.
9. Fixation device according to claim 1, wherein the opening has an
inner surface which is at least partially structured.
10. Locking screw with a screw head, wherein the locking screw, at
least in the area of the screw head, is provided with at least one
opening.
11. Method of fixing an elongate element in a retaining structure
with a locking screw, wherein the locking screw contains a screw
head and is provided, at least in the area of the screw head, with
at least one opening, the method comprising the step of fixing the
elongate element inserted into the opening.
12. Combination of a fixation device according to claim 1 and an
elongate element, the elongate element being selected from the
group including wire, rod, pin, profile, spring, hollow tube,
scalpel.
13. Combination according to claim 12, wherein the elongate element
has at least partially a structured surface.
14. Combination according to claim 12, wherein the elongate element
is provided at least partially with a surface structure selected
from the group consisting of a thread, a drill helix, and a
knurling.
15. Combination according to claim 12, wherein the elongate element
has a tip which has a design selected from the group consisting of
a lancet and a trocar.
16. Combination according to claim 12, wherein the elongate element
is provided with a self-cutting or self-drilling thread.
17. Arrangement with a combination according to claim 12 and with a
retaining structure having at least one seat for receiving the
fixation device.
18. Arrangement according to claim 17, wherein the seat and the
fixation device are designed in such a way that the elongate
element can be secured by the fixation device in a plurality of
different angle positions relative to the retaining structure.
19. Arrangement according to claim 17, wherein the at least one
seat is provided, on its inner wall, with at least one radially
inwardly extending taper.
20. Arrangement according to claim 17, wherein the inner wall, seen
in the longitudinal direction, is provided with a rounded inner
contour.
21. Arrangement according to claims 17, wherein the retaining
structure is selected from the group including a retaining
structure for receiving an endoscopy tube, the elongate element
being designed as a tube or trocar, a temporary intraoperative
support element, a surgical frame that can be fixed on the
operating table, an internal fixator, a wire fixator, a cable
fixator, an intramedullary pin, an external fixator, a scalpel
holder, the elongate element being designed as a scalpel blade or
as a scalpel shaft.
22. Osteosynthesis set, including at least two implant plates,
wherein each implant plate is provided with at least one seat for
receiving a connecting arrangement, with at least one connecting
arrangement which can be inserted into a seat of each of the
implant plates, wherein the implant plates can be connected to one
another and stabilized by means of the connecting arrangement of
the implant plates.
23. Osteosynthesis set, including an implant plate with at least
two sections, wherein each section is provided with at least one
seat for receiving a connecting arrangement, with at least one
connecting arrangement which can be inserted into a seat of each of
the sections, wherein the sections can be connected to one another
and stabilized by means of the connecting arrangement of the
implant plates.
24. Osteosynthesis set according to claim 22, wherein the
connecting arrangement comprises at least one fixation device for
fixing an elongate element in a seat of a retaining structure and
at least one connecting means, wherein the fixation device contains
a main body, which has an opening for receiving the elongate
element, the main body, at least in a clamp area, is radially
deformable relative to the elongate element, such that the
dimension of the opening can be reduced, the main body has an outer
contour which is designed in such a way that, when the fixation
device is inserted into the seat, the clamp area can be deformed
such that the elongate element can be clamped securely in the
opening.
25. Osteosynthesis set according to claim 22, wherein the
connecting arrangement comprises a locking screw and at least one
connecting means, wherein the locking screw has a screw head and is
provided with at least one opening, at least in the area of the
screw head.
26. Osteosynthesis set according to claim 22, wherein the
connecting arrangement comprises an elongate element with a thread
at at least one end and a connecting element, into which the thread
can be screwed and by means of which the elongate element can be
secured in one of the implant plates.
27. Osteosynthesis set according to claim 23, wherein the
connecting arrangement comprises an elongate element with a thread
at least one end and a connecting element, into which the thread
can be screwed and by means of which the elongate element can be
secured in one of the implant plates.
Description
[0001] The invention relates to a fixation device, a combination of
such a fixation device with an elongate element, and a
corresponding arrangement with a retaining structure, and an
osteosynthesis set, according to the features of the preambles of
the independent patent claims.
[0002] Various types of fixation devices are used in bone surgery.
In various indications, an elongate element, for example a
Kirschner wire, has to be secured on a retaining structure, for
example an internal or external fixator. Various arrangements are
known for securing the wires in the retaining structure.
[0003] U.S. Pat. No. 4,941,481 and U.S. Pat. No. 4,620,533, for
example, disclose clamp-like devices which can be guided in the
manner of a clamping jaw over an elongate element and in so doing
fix the latter. U.S. Pat. No. 6,702,814 discloses a clamping device
which can be used for an external fixator and in which two clamping
jaws form a channel for receiving an elongate element. One of the
clamping jaws is elastically deformable in order to receive the
elongate element.
[0004] U.S. Pat. No. 5,393,191 discloses an external fixator in
which an elongate element can be guided into a slotted ball that
can be pressed in between two clamping jaws. The orientation of the
elongate element received in the ball can be adjusted in this
way.
[0005] A surgical guide body is known from EP 1 202 675. The guide
body is used to receive fixation elements and for this purpose has
a plurality of openings inclined relative to one another. By means
of an intermediate piece, a longitudinal fixation element, for
example a wire, can be fixed by pressing, clamping or friction.
[0006] Other fixation devices for elongate elements are known from
U.S. Pat. No. 2,346,346, U.S. Pat. No. 4,890,631, U.S. Pat. No.
5,702,394, EP 1 408 859, WO 03/105704, EP 1 736 109, EP 1 570 796,
U.S. Pat. No. 4,621,627, EP 1 741 396, EP 1 306 057, U.S. Pat. No.
4,135,505, U.S. Pat. No. 4,127,119 or DE 3439795, WO 03/065911.
[0007] However, all these known solutions are associated with
various disadvantages. In particular, many of the known solutions
are made up of a plurality of individual elements. Production and
use is therefore complicated and also expensive. A further
disadvantage of known solutions is that the elongate elements to be
fixed can often be secured only in one direction, or they can be
secured in different directions only by means of structurally
complex solutions.
[0008] It is true that EP 1 202 675 discloses a solution in which a
position is possible in different directions without complicated
ball joints. However, different directions are in this case also
only possible in a defined and limited number according to
preformed, inclined openings of the guide body. A correction of the
direction is not possible.
[0009] It is therefore an object of the present invention to avoid
the disadvantages of the known solutions, in particular therefore
to make available a fixation device for fixing elongate elements
which is easy and inexpensive to produce and can be handled in a
simple manner. The fixation device is nonetheless intended to allow
the direction of the elongate element to be selected as freely as
possible and, if appropriate, to be corrected. A further object of
the present invention is to make available a corresponding fixation
device that can be repositioned in a simple manner, for example for
fixing an elongate element at a different angle than originally
provided.
[0010] A further object of the present invention is to make
available such a fixation device in combination with an elongate
element, and an arrangement with such a combination and with an
additional retaining structure, which also meet the abovementioned
objects.
[0011] A further aspect of the invention additionally concerns an
osteosynthesis set made up of at least two implant plates. When
treating osteoporotic bone in particular, a problem that often
arises is that implant plates with threaded screws cannot be
anchored sufficiently securely in the bone substance. According to
this aspect of the invention, it is an object to make available an
osteosynthesis set which is suitable for solving the known
problems, in other words which permits a secure fixation of the
implant plates even when insufficient or unsuitable bone substance
means that conventional fixation with a screw is not possible or
the hold of the screw does not provide adequate stability.
[0012] According to the invention, these objects are achieved with
a fixation device, with a combination of such a fixation device and
an elongate element, with an arrangement having such a combination,
and with an osteosynthesis set, these having the features of the
characterizing parts of the independent patent claims.
[0013] The fixation device according to the invention is used to
fix an elongate element, in particular a wire, pin, tube or a
thread, in a seat of a retaining structure. The retaining structure
is typically a plate. However, the term retaining structure is to
be interpreted widely. Applications are also conceivable in which
the retaining structure primarily applies the clamping forces
described below, and is not used for actually holding the fixation
device. The fixation device has a main body. The main body is
provided with an opening, in particular a continuous bore, for
receiving the elongate element. The opening can extend in the
longitudinal direction. It is also conceivable, however, to provide
openings in the transverse direction (i.e. at an angle of more than
0.degree. to the longitudinal axis) of the main body, for example
for distraction. While the opening for receiving the elongate
element is typically round (when used to receive cylindrical
objects such as wires), other shapes of the opening are also
conceivable. For example, a slit-shaped opening for receiving
planar elongate elements is also conceivable. Differently shaped
openings for receiving profiled elongate elements are also
conceivable.
[0014] According to the invention, the main body, at least in an
outer clamp area, is radially deformable such that the dimension of
the opening, in particular the diameter of the bore, can be
reduced. In the context of the present application, outer clamp
area is to be understood as that area in which the main body is
compressed by contact with the seat in the retaining structure. The
main body additionally has an outer contour which is designed in
such a way that, when the fixation device is inserted into the
opening of the retaining structure, the clamp area can be deformed
radially such that the elongate element can be clamped securely in
the opening. Viewed in the direction of the elongate element, the
secure clamping can be effected axially at the same height at which
the clamp area is arranged. It is also conceivable, however, to
provide for the elongate element to be clamped axially at a
distance from the outer clamp area of the main body. Before
insertion into the retaining structure, the elongate element can
easily be inserted into the opening of the main body. When
inserting the main body into the seat of the retaining structure,
the main body is radially compressed by virtue of the specific
configuration of its outer contour. In this way, the elongate
element is securely clamped in the opening of the main body, such
that it can no longer be displaced in the axial direction. The
solution according to the invention is particularly simple, since,
in addition to the elongate element and the retaining structure,
only one additional component (the fixation device) is necessary
for fixing the elongate element.
[0015] According to a first preferred embodiment of the invention,
the fixation device is provided, in its clamp area, with at least
one slit. The slit extends at least partially in the direction of
the opening and ends at least partially in the opening. The slit
can reach as far as the outer wall of the fixation device. The slit
does not necessarily have to extend in a plane and instead can have
one or more bends or curves. By virtue of this at least one slit,
the main body can be radially compressed particularly easily. One
slit may itself be sufficient. However, any desired greater number
of slits can also be provided. The slit or slits are arranged in
the radial direction for example. However, it is also conceivable
to provide areas of weakening in the main body by means of
tangential or curve-shaped slits. The slit typically extends
exactly in the direction of the opening for receiving the elongate
element. However, it is also conceivable to provide the slit at
angles relative to the axis of the fixation device. Alternatively,
however, it is also conceivable for the main body to be made of an
elastic material. In this case, a radial compression can be
achieved even without a slit. In addition, in order to simplify the
insertion of the elongate element, the main body can also be made
up of several mutually movable parts. Two parts connected by a
hinge are conceivable. These parts can be opened out for insertion
of the element and then closed again and connected to each other.
The axial fixation of the elongate element is then effected once
again in the manner described above.
[0016] In addition, it is also conceivable for the main body to be
made from several materials and with several components. For
example, elastic material could be used for the clamp zone, and
tough material for the locking zone and screwdriver zone. Such a
fixation device can be produced, for example, by multi-component
injection moulding.
[0017] According to another preferred embodiment, the fixation
device, at least in the clamp area, is provided on its outer
contour with at least one clamp surface. The clamp surface at least
partially widens radially, seen in the circumferential direction. A
main body with such a structure, but without an elongate opening
and without slits, is known from WO 04/086990 for locking a bone
screw in an implant plate. When the screw head with the clamp
surfaces is brought by means of rotation into contact with
corresponding wedge projections of a seat of a retaining structure,
radial forces arise that lead to a compression of the main body. It
has been found that such a locking screw is particularly suitable
for fixation of elongate elements if it is provided with an
elongate opening for receiving the element and with means for
facilitating the radial compression, for example slits.
[0018] Moreover, the fixation device according to the invention
particularly preferably has a main body which, seen in the
longitudinal direction, has a rounded outer contour in the area of
the clamp surface, in particular at least partially an
approximately spherical, spiral, parabolic, elliptic or hyperbolic
contour. A contour is generally preferred which allows the
direction of the fixation device in a seat of a retaining structure
to be adjusted in an almost unlimited manner within a defined angle
range. No additional components such as ball joints, clamping jaws
or the like are needed for this purpose. It is also conceivable,
however, to provide a main body with a cylindrical or conical outer
contour, if at the same time a retaining structure with a seat is
made available which has a correspondingly rounded contour. The
outer face of the main body and/or the seat of the retaining
structure can additionally be structured, for example with fluting
or knurling.
[0019] According to another preferred embodiment of the invention,
the fixation device, at least in its clamp area, is designed as a
screw head. The design as a screw head in particular permits simple
rotation of the fixation device in the circumferential direction.
In the above-described design with clamp surfaces widening radially
in the circumferential direction, the radial compression can be
achieved in a particularly simple manner by rotation using a
screwdriver, for example with a cross-head, Torx, hexagon socket or
variations thereof, for example the Applicant's "HexaDrive".
[0020] On its main body, the fixation device can additionally be
provided with a screw shank with a screw thread. It is also
conceivable, however, to additionally provide the fixation device
with a shank of a pin. Therefore, depending on the application, it
may be advantageous to use a fixation device composed exclusively
of a main body, or a fixation device in which the main body is
additionally provided with the shank of a pin or of a screw.
[0021] According to another preferred embodiment of the invention,
the fixation device, when designed as a screw head in its clamp
area, can additionally be provided with an extension above the
clamp area. The extension is designed as a seat for a screwdriver.
In this way, a torque can be applied particularly easily to the
fixation device.
[0022] According to another preferred illustrative embodiment of
the invention, the at least one slit, seen in the longitudinal
direction of the fixation device, extends at least over the clamp
area. It is also conceivable, however, for the slit or slits to
extend over a longer axial area, in order to further increase the
deformability and flexibility of the main body. At most, the slits
extend along the entire length of the fixation device. By suitable
choice of length of the slits, it is possible to adjust the
clamping action on the elongate element.
[0023] According to another preferred embodiment of the invention,
the inner surface of the opening can be structured. In this way, it
is possible, by means of an additional form fit, to achieve
increased retention in the axial direction as a result of the
radial compression. In other words, this means that, with a given
clamping force, a greater force would have to be applied to the
elongate element in the axial direction in order to tear it from
the fixation device.
[0024] In accordance with the above embodiments, one aspect of the
invention is also that a locking screw known per se is additionally
provided with a longitudinal bore and, in the area of the screw
head, with at least one slit. It is particularly preferable here to
use a locking screw of the type shown and claimed in WO
2004/086990. The subject matter of said application, and in
particular of the claims of WO 04/086990, is hereby expressly
incorporated in the present application.
[0025] A further aspect of the invention therefore lies in the use
of such a locking screw for fixation of an elongate element in a
retaining structure. By using a multi-directional locking screw,
however, the elongate element can also be fixed in the longitudinal
direction in a defined angle position, which can be freely selected
within a range of angles.
[0026] Yet another aspect of the invention concerns the combination
of a fixation device as described above and an elongate element.
The elongate element is selected from the group including wires,
rods, pins, profiles, springs, hollow tubes, or an instrument for
manipulation, for example a scalpel or spatula (e.g. for
manipulations on the brain). If the elongate element is designed as
a wire, rod or pin, applications are possible for example with an
internal fixator or an external fixator. If the elongate element is
designed as a profile or a hollow tube, applications as an
endoscopy tube or for fixation of a drill guide are also
conceivable, for example. If the elongate element is designed as a
fixture for a scalpel, the fixation device according to the
invention can additionally be used as scalpel holder for holding a
scalpel. The shaft of the scalpel can be inserted into the elongate
bore. In such an application, however, it is also conceivable not
to provide a longitudinal bore in the fixation element, and instead
to directly fit a part of the blade of the scalpel into slits
present on the fixation element.
[0027] To increase the axial clamping effect, the elongate element
can additionally have a structured surface.
[0028] It is also conceivable, depending on the application, to
provide the elongate element with a thread or with knurling in the
longitudinal direction or transverse direction or also to provide
it with a drill helix.
[0029] According to another preferred embodiment, the elongate
element can be provided with a tip which is designed as a lancet or
trocar, or which is provided with a self-cutting or self-drilling
thread.
[0030] A cable/cord is also conceivable as an elongate element for
transmitting tensile forces or for connecting torn soft-tissue
parts such as tendons or ligaments or for fixing bone
fragments.
[0031] A further aspect of the invention concerns an arrangement
composed of the above-described combination of a fixation device
and an elongate element together with a retaining structure. The
retaining structure has at least one seat for a fixation
device.
[0032] The seat for the fixation device is particularly preferably
provided with radially inwardly directed projections or tapers.
These tapers, together with the clamp surfaces on the fixation
device, lead to a radial compression of the main body. To permit
the simplest possible multi-directional positioning of the fixation
device and therefore also of the elongate element held therein, the
opening is also preferably provided with an inner wall which, in
the longitudinal direction, has at least partially an approximately
spherical, spiral, parabolic, elliptic or hyperbolic shape. In
particular, the opening is designed in accordance with the
disclosure and claims in WO 04/086990.
[0033] The retaining structure can, for example, be designed as a
retaining structure for an endoscopy tube, which is retained in the
retaining structure by the fixation device. In this case, the
elongate element is an endoscopy tube.
[0034] The retaining structure can also be designed as a temporary
intraoperative support element, for example as a fixation ring for
an arthrodesis set.
[0035] Typical temporary intraoperative applications are
applications in which certain bones are intended to be fixed for a
limited time. Before the end of the surgical intervention, the
corresponding support structure is removed. Indications are, for
example, arthrodesis or partial arthrodesis of the wrist,
neurosurgery, osteotomies, correction of fractures, and minimally
invasive interventions, for example transbuccal interventions or
spinal column surgery. External fixator is understood as an
application in which, following surgery, the stabilizing or fixing
structures are used outside of the body for avoiding bone movements
and therefore for healing fractures. It is also conceivable,
however, to fix certain degrees of freedom of structures (e.g. two
bones connected by a joint) and to leave other degrees of freedom
of the same structure deliberately alone in terms of their mobility
(dynamic external fixator). This permits early postoperative
physiotherapeutic exercise for preventing adhesion of soft-tissue
parts and stiffening of the affected joints. These can typically be
osteotomies, corrections or fracture treatments. Application in a
ring fixator is also conceivable, where several rings can be fixed
to one another likewise by means of the fixation device according
to the invention. A use in the treatment of fractures of the upper
arm is also conceivable, where the ball of the joint is held with a
threaded wire, and the position can be very finely adjusted via a
nut that bears on the screw head (pull-push instrument).
[0036] The retaining structure can additionally be formed by a
surgical frame which can be secured by the fixation device to an
operating table, for example in neurosurgical applications for
holding drill sleeves or guide sleeves or spatulas.
[0037] In an application as an internal fixator, the arrangement as
an implant for avoiding bone movements and for healing fractures
remains permanently in the body. Typical applications may be
arthrodesis or partial arthrodesis, stiffening of the spine,
treatment of long bones in proximity to the joints, the epiphysis,
all osteotomies, corrections or fracture treatments, wire
osteosynthesis, using a plate with at least one hole, or skeletal
anchoring in orthodontics. A wire fixator or cable fixator for
generating tensile forces in soft-tissue parts is also
conceivable.
[0038] In an application as an endoscope, manipulations in the body
can be performed via the bore in the fixation device (for example
in neurosurgery, oral surgery, orthodontics or facial surgery, in
particular in transbuccal interventions, or in surgery of the
spinal column or of the pelvis).
[0039] In the three last-mentioned cases, the elongate element is
typically a wire or a tube/sleeve. Finally, the retaining structure
can also be designed as a holder for an instrument, such as a
scalpel, and in this case the elongate element is the blade shaft
of the scalpel or a part of the blade.
[0040] While surgical applications have primarily been described
here, other applications of the fixation device according to the
invention, of the combination with an elongate element, and of the
arrangement according to the invention are also conceivable. For
example, such constructions can be used as quick-coupling systems
for K-wires/drills in driving or drilling machines, as clamping
mechanisms for grip pieces, e.g. in electrosurgery or for bone
distraction (e.g. of palate, alveolar ridge). In applications for
distraction, the elongate element can, for example, be designed in
two parts, one part having an inner thread and one part having an
outer thread. A fixation device with two transversely bored main
bodies is used to receive one of the parts respectively. If the
main bodies are each anchored in a bone fragment, the parts can be
secured and used for distraction.
[0041] Other applications are also conceivable, however, e.g. in
the construction field, e.g. in shelving, scaffolding, pegging
(optionally with axial compression) or for shoring.
[0042] A further aspect of the invention concerns an osteosynthesis
set. The set is made up of at least two implant plates or of one
implant plate with at least two sections. The implant plates or the
sections each have at least one seat for receiving a connecting
arrangement. The set additionally comprises such a connecting
arrangement. The connecting arrangement can be inserted into a
respective bore of the plates or of the sections. The implant
plates can be connected to one another and stabilized by means of
the connecting arrangement of the implant plates. The plates are
prevented from moving relative to each other along the elongate
element. The firm fixation results in a connection of one or more
plates. Fragments are then repositioned and fixed on this
structure. In the case of a plate with two sections, a connection
of one section, for example a tab of a plate, to another plate
section can be created. This can be advantageous, for example, when
the connection between the two plate sections has to be designed,
for clinical reasons, such that it can transmit only a slight load
or indeed no load or, for clinical reasons, is removed after the
connection is established.
[0043] By virtue of the connecting arrangement, two or more such
implant plates can be secured/connected at several locations of a
bone, even when the bone, on account of its size or structure
(internal makeup), is not suitable for receiving a bone screw for
fixation of the implant plates.
[0044] It is also conceivable, in this context, to provide implant
plates with tab-like parts that are angled off. The connecting
arrangement can then be secured in a seat in this tab. This is
particularly advantageous when, for anatomical reasons, the
connection described above is not possible with flat plates, for
example because the planes in the area of the seat are not arranged
relative to one another by an angle which is smaller than the
pivoting angle of the fixation elements. The angled-off parts then
form small units that offer a position that can be used for the
connection.
[0045] The connecting arrangement particularly preferably comprises
a fixation device of the type described above. In this way,
clamping wires can be secured in a particularly easy way in the
openings of the implant plates. For certain applications, for
example cranial and maxillofacial applications, it is also
conceivable to skew the angle of the seat relative to the plate,
that is to say to orient the axis of the seat not perpendicular to
the plane of the plate. A positioning of the screws in a wider
angle range can thus be achieved, e.g. in a range of 15.degree.
(30.degree.-15.degree.) to 45.degree. (30.degree.+15.degree.) for a
seat inclined by 30.degree.. In thin plates in particular, the
plate can be thickened locally in the area of the seat. In this
way, space is created for the inclined arrangement of the locking
contour in the seat.
[0046] Alternatively, however, it is also conceivable that the
connecting arrangement comprises an elongate element with a thread
at at least one end. In addition, the connecting arrangement is in
this case provided with a connecting element, e.g. a nut, into
which the thread can be screwed and by means of which the elongate
element can be secured in one or both of the plates.
[0047] The invention is explained in more detail below on the basis
of illustrative embodiments and with reference to the drawings, in
which:
[0048] FIG. 1 shows a side view of a fixation device according to
the invention;
[0049] FIG. 2a shows a cross section of a fixation device according
to FIG. 1, along the plane CC;
[0050] FIG. 2b shows a cross section through a plane along a slit
of the fixation device;
[0051] FIG. 3 shows a plan view of the fixation device according to
FIG. 1;
[0052] FIG. 4 shows a bottom view of the fixation device according
to FIG. 1;
[0053] FIG. 5 shows a schematic view of a fixation device according
to the invention designed as a screw;
[0054] FIG. 6 shows a perspective view of an opening for receiving
the fixation device according to the invention;
[0055] FIG. 7a shows a schematic view of a first alternative
illustrative embodiment of a fixation device according to the
invention;
[0056] FIG. 7b shows a schematic view of another alternative
illustrative embodiment of a fixation device according to the
invention;
[0057] FIG. 8 shows a schematic view of an osteosynthesis set made
up of two implant plates;
[0058] FIGS. 9a and b show alternative embodiments for an
osteosynthesis set with two implant plates;
[0059] FIG. 10 shows a schematic view of the use of a fixation
device according to the invention in an external fixator;
[0060] FIG. 11 shows a schematic view of the use of fixation
devices according to the invention as temporary intraoperative
fixation;
[0061] FIGS. 12 to 19 show various embodiments of elongate elements
that can be used in connection with the present invention.
[0062] FIG. 1 shows a fixation device 10 according to the invention
in a side view. The fixation device 10 has a main body 11. The main
body 11 is a seat of a retaining structure, for example can be
inserted into the seat 63 in an implant plate 61, e.g. according to
FIG. 6. The main body has a clamp area 13. In the clamp area 13,
the main body 11 can be compressed by contact with the inner wall
65 of the seat (see FIG. 6). The main body 11 additionally has
slits 15 extending in the axial direction A. Because of the slits
15, the main body 11 can be compressed in the radial direction r
(i.e. in a plane perpendicular to the axial direction A). The main
body 11 has an outer contour 14. The outer contour 14, at least in
an area 18, is rounded when viewed in the axial direction A. By
means of the rounded outer contour 18, the main body or fixation
device can be inserted into a seat 63 in a large number of
different angle positions.
[0063] The main body 11 is additionally provided with a bore 12
(see FIGS. 2a and 2b). The bore 12 is used to receive an elongate
element. The diameter D of the bore 12 can be reduced by
compression in the radial direction r. In this way, an elongate
element, typically a wire, inserted into the bore 12 is securely
clamped. To increase the clamping action, the inner surface 17 of
the bore 12 can additionally be provided with a surface
structuring.
[0064] FIG. 2b shows a cross section through the main body 11 in a
plane along the slit 15. As FIG. 2b shows, the slit 15 extends from
one edge of the main body 11 as far as the bore 12.
[0065] As FIGS. 3 and 4 show, the outer contour of the main body
10, in a plane perpendicular to the axial direction A, is provided
with three clamp surfaces 16. The clamp surfaces 16 widen radially,
seen counter to the circumferential direction U. If the main body
11 is inserted into a correspondingly designed opening with radial
projections 64 (see FIG. 6) and is turned in the circumferential
direction U, the clamp surfaces 16 come into engagement with the
projections 64. This results in a compression in the radial
direction.
[0066] To generate a rotation movement, the main body 11 is
additionally provided, in the area of the bore 12, with a seat 5
for a corresponding tool, for example a screwdriver.
[0067] FIG. 4 shows a bottom view of the three slits 15, which are
offset by 120.degree. to one another and which extend exactly
radially in FIG. 4. Other geometries of the slits are of course
conceivable. As FIG. 1 shows, the slits 15 extend approximately
along two thirds of the height of the main body 11. Of course,
other dimensions of the slits in the longitudinal direction are
also conceivable. It is also conceivable for the slits to be curved
or tangential.
[0068] In medical applications, the fixation device according to
the invention is made of a biocompatible material. Typically,
titanium can be used. Other materials are also conceivable, such as
stainless or bioabsorbable materials. It is also possible to use
alloys with shape-memory properties, for example Nitinol or
generally superelastic materials, and for example also plastic.
[0069] The dimension of the fixation device according to the
invention depends on the particular field of application.
Typically, for applications in the surgical field, fixation devices
with a diameter of ca. 2 to 7 mm, bores with a diameter of ca. 0.75
to 1.4 mm and fixation devices with an overall height of ca. 1 to 5
mm are conceivable. The slits can typically have a slit width of
0.2 to 0.3 mm and extend over a height of 0.3 to 1.5 mm. Variations
are of course conceivable, depending on the field of application,
for example in spinal surgery where endoscopes with diameters of
10-50 mm and bores with diameters of 5-40 mm are known.
[0070] FIG. 5 shows a three-dimensional representation of a
fixation device designed as a screw 1. The main body 11 according
to FIG. 1 is adjoined by a screw shank 2, which is provided with a
screw thread 3. Except for the bore 12 and the slits 15, the screw
is designed in accordance with WO 04/086990. The screw shank 2 with
the thread 3 can have advantageous properties depending on the
indication. However, it is also conceivable to omit the screw shank
2 or to design it as a pin without a screw thread.
[0071] FIG. 6 shows an example of a seat 63 for the fixation device
10. The seat 63 has an inner wall 65. The inner wall 65 is provided
with projections 64 extending inwards in the radial direction. In
FIG. 6, the seat 63 is designed as part of an implant plate 61. The
seat is designed in accordance with WO 04/086990. Of course,
corresponding openings can be provided in any desired retaining
structures into which elongate elements are intended to be inserted
by means of the fixation device.
[0072] The plate 61 shown in FIG. 6 with the opening 63 is
otherwise identical to the plate shown in WO 04/086990. The content
of WO 04/086990 relating to the seat is also expressly incorporated
by cross reference into the present application. In particular, the
inner wall 65 has a partially spherical, spiral, parabolic,
elliptic or hyperbolic shape in the axial direction A, such that
the fixation device with its rounded outer contour 18 can be
inserted multi-directionally into the opening 63 and, by turning in
the direction U, can be clamped securely in the opening 63.
[0073] FIG. 7a is a schematic view of an alternative embodiment of
a fixation device according to the invention. The fixation device
according to FIG. 7a is designed as a screw 1'. In the area of the
screw head 10', the screw 1' has a main body 11'. The main body 11'
is provided with a slit 15' extending in the axial direction of the
screw 1'. A clamp area 13' is formed by the slit 15'. The main body
11' has a similar design to the main body shown in FIGS. 1 to 4. By
inserting the main body 11' into a seat 113 of a retaining
structure designed as locking element 110, and by turning it, the
main body 11' can be compressed in a plane perpendicular to the
axis of the screw 1'. That is to say, the width of the slit 15' is
thus reduced. A wire 20, inserted into an opening 12' extending
transverse to the screw axis, is thus securely clamped in a
direction transverse to the screw axis. It is unimportant here
that, seen in the axial direction, the opening 12' is arranged
underneath the clamp area 13'. The arrangement shown in FIG. 7a can
be used, for example, for distraction if, instead of a wire 20, a
two-piece elongate element with inner thread and outer thread
meshing on each other is used.
[0074] FIG. 7b shows another alternative embodiment. An implant
plate 41 is used as internal fixator for the head of a radius K.
For this purpose, wires 40 introduced into the bone K are secured
in openings 43 of the plate 41 by means of the fixation devices 10
described above. The fixation devices 10 permit an axial fixation
of the wires 40. At the same time, the wires can be inserted at
different angles relative to the surface of the plate and can be
locked in their angle position. FIG. 7b shows an inner contour for
receiving a tool, typically a screwdriver. With this tool, the
fixation device 10 can be subjected to a torque, turned, and
thereby clamped.
[0075] FIG. 8 shows another possible use of a fixation device
according to the invention. Two implant plates 61, 62 are
positioned on two sides of a bone K. Two wires 60 are introduced
through the bone and are guided through corresponding bores 63 in
the implant plates 61, 62. By means of the fixation devices 10
described above, the wires 60 are secured at stable angles in the
bores 63. The direction of the wires 60 can be selected freely, by
virtue of the free positioning described above. By means of the
wires 60, the two implants 61, 62 are connected to each other along
the wires 60 in the area of the openings 63 and are thereby
stabilized. In this way, a force can be applied, even when the bone
substance is not present in sufficient quantity or quality to
receive a conventional bone screw.
[0076] The osteosynthesis set shown in FIG. 8, composed of the
plates 61, 62, the wires 60 and the fixation devices 10, allows
such implants also to be used in osteoporotic bone for example.
FIGS. 9a and 9b show alternative embodiments of such osteosynthesis
sets.
[0077] FIG. 9a shows an alternative illustrative embodiment of an
osteosynthesis set. According to FIG. 9a, two implant plates 71, 72
are connected by wires 100. In the same way as is shown in FIG. 8,
each wire 100 is fixed in a seat of one implant plate 71 by means
of a clamping device 10. The fixation is effected largely in the
manner explained with reference to FIG. 8. In the area of the
second implant plate 72, the wire 100 has a thread. A nut 73, e.g.
of PEEK, is screwed onto the thread and thus fixes the wire 100 in
the area of the second implant plate 72. With such an arrangement
too, stabilization can be achieved in direction R, where R does not
have to be oriented perpendicular to the plane of the plate.
[0078] In FIG. 9b, two implant plates 71, 72 are connected to each
other by screws 70. A nut 73 or a small disc with an opening is
connected to the end of the screw 70 in the area of one plate 72.
The screws 70 are supported with their screw heads 74 on the other
plate 71. With this stabilization too, a connection of the implant
plates 71, 72 in direction R can be achieved, where R does not have
to be perpendicular to the plane of the plate.
[0079] Nut is understood here in particular as any type of abutment
for the wire. The nut does not necessarily have to be arranged
parallel to the plane of the plate. The nut can also have a certain
pivoting range. The nut can also be able to be locked. Finally, the
nut does not necessarily need to have an opening. A self-drilling
wire tip can also drill itself a hole. In addition, the nut can
also be preassembled in the plate.
[0080] To connect the plates according to FIGS. 7, 7b, 8, 9a and 9b
and to stabilize the fragment positions, a wire has to be fitted.
For this purpose, a targeting device is used which threads the wire
into the start hole and target hole. After the wire has been
introduced, the line of connection between these two points
corresponds to the wire axis. The clamp elements are then engaged
and, by turning them in the circumferential direction U, are
blocked in the opening. A pivoting of the fixation device 10 is
possible on account of the rounded outer contour, seen in the axial
direction, but is limited by the geometry of the implant plates 61,
62 to a certain angle range, typically of at most
.+-.15.degree..
[0081] By means of this pivotability, the plates can be positioned
exactly according to the anatomical conditions, without having to
take into account the subsequent connection of the plates. In
non-multidirectional and non-pivotable systems, compromises would
have to be made when adapting them to the anatomical
conditions.
[0082] FIG. 10 is a schematic view of the use of fixation devices
according to the invention in an external fixator. The external
fixator, typically for a humerus, has two rings 31. The rings 31
are intended to be stabilized relative to each other by wires 30.
At the same time, the structure composed of the two rings 31 and
the wires 31 extending approximately in the direction of the bone K
is intended to be fixed to the latter by wires 30' extending
perpendicular to the bone. In order to secure the wires 30, 30' in
the rings, fixation devices 10 are fitted in openings 33 of the
rings or in openings 33 of auxiliary elements 34 mounted on the
rings. The fixation devices 10 and the openings 33 are designed as
described above. In addition, the fixation devices 10 can be
provided with an extension 4, which is used for receiving a tool or
for (manual) manipulation.
[0083] FIG. 11 is a schematic view of a use of the fixation device
10 according to the invention for temporary intraopertaive fixation
of a metacarpal. A fixation ring 21 bears on the hand or sweeps
across it and is secured to the operating table, e.g. with a
fixation device as described above. Fixation wires 20 serve for
temporary fixation. The wires 20 are guided through the bore 12
(see, for example, FIGS. 2a and 2b) of the fixation device 10. The
fixation devices 10 are screwed into corresponding openings 23 on
the fixation ring 21. By turning the fixation device in the
circumferential direction U (see also FIG. 3), the fixation devices
10 can be fixed and radially compressed in the openings 23. In this
way, the wire 20 is fixed in the axial direction in the fixation
device 10, and the fixation ring is also fixed against tilting. The
openings 23 have a similar design to the opening shown in
connection with the implant plate in FIG. 6. Depending on the
application, different sizes of fixation devices 10 can be
used.
[0084] FIGS. 12 to 19 show various embodiments of elongate elements
that can be inserted into the fixation device 10 according to the
invention.
[0085] FIG. 12 shows schematically a simple wire 20 without any
defined contouring of the surface.
[0086] FIG. 13 shows a wire 80 which is provided with a thread 81
along its entire length. Typical applications are, for example,
K-wires with a short thread (ca. 20 mm) or with a thread along the
whole length. The thread at the tip can be used, for example, to
secure a bone fragment against axial displacement on the K-wire.
The thread on the entire shaft additionally represents an
inexpensive structuring transverse to the longitudinal axis, which
can additionally serve to increase the retention force. Instead of
a structuring of the surface in the form of a thread 81, knurls
extending in the longitudinal direction or in the transverse
direction are also conceivable.
[0087] FIG. 14 shows a wire-like element 90 which is provided at
its end with a trocar bevel 91.
[0088] FIG. 15 shows a wire-like element 100 which is provided with
a thread 101 only at its tip.
[0089] FIG. 16 shows an endoscopy tube 50. An elongate element of
tubular shape, as shown in FIG. 16, can also be used in connection
with a lancet bevel.
[0090] FIG. 17 shows a scalpel 20 which can be secured with its
shaft 121 in a fixation device according to the invention.
[0091] FIG. 18 shows a tubular element 131 which is used to receive
a wire bundle 132. In osteoporotic bone of the upper arm, there is
a danger of the joint surface collapsing. If the element 131 is
fixed in a plate anchored on the shaft of a bone, the ends of the
wire bundle can support the osteoporotic bone in the area of the
joint surface from the inside. The tubular element then assumes the
function of an elongate element, which is fixed in a fixation
device 10 (see, for example, FIGS. 1 and 2) of the kind described
above. It is also conceivable to provide the tube with a suitable
outer contour (not shown), such that the tube meets the object of a
fixation device according to the invention for holding the wire
bundle.
[0092] However, for this purpose it is also possible to use a
K-wire with a large end face with an element that folds open or a
slotted wire.
[0093] FIG. 19 shows a spring-like element 141. The spring-like
element 141 is composed of two interconnected helical springs. As
spring element it is also possible to use leaf springs, helical
springs, or also a spring made up of two spiral springs pushed one
inside the other.
[0094] The elongate elements are made of suitable materials
depending on the particular application. Typically, titanium can be
used for implantable elements. Other materials that can conceivably
be used are stainless materials, shape-memory alloys, elements of
superelastic materials, or also plastic.
* * * * *