U.S. patent application number 11/042385 was filed with the patent office on 2005-06-09 for anatomical interbody implant and gripper for same.
Invention is credited to Bernard, Pierre M., Pointillart, Vincent.
Application Number | 20050125029 11/042385 |
Document ID | / |
Family ID | 9548084 |
Filed Date | 2005-06-09 |
United States Patent
Application |
20050125029 |
Kind Code |
A1 |
Bernard, Pierre M. ; et
al. |
June 9, 2005 |
Anatomical interbody implant and gripper for same
Abstract
The invention relates to an intersomatic implant designed to be
inserted in the disk space defined between two adjacent vertebrae,
namely an overlying vertebra and an underlying vertebra, for the
purpose of reestablishing the anatomic space between the vertebrae,
the implant being in the form of a cage (1) that is generally in
the shape of a rectangular block having at least two sagittal walls
(2, 3) interconnected at least by an anterior transverse wall (4)
and by a posterior transverse wall (5), the walls (2 to 5)
presenting rims (10) extending on one surface to define a first
transverse face (8) and on the other side to define a second
transverse face (9). According to the invention, the implant
comprises: a first transverse face (8) presenting in the sagittal
plane a convex profile congruent with the sagittal anatomic profile
of an overlying vertebra; and a second transverse face presenting
in the frontal plane a convex profile congruent with the frontal
anatomic profile of an overlying vertebra.
Inventors: |
Bernard, Pierre M.;
(Bordeaux, FR) ; Pointillart, Vincent; (Bordeaux,
FR) |
Correspondence
Address: |
LADAS & PARRY LLP
224 SOUTH MICHIGAN AVENUE
SUITE 1200
CHICAGO
IL
60604
US
|
Family ID: |
9548084 |
Appl. No.: |
11/042385 |
Filed: |
January 25, 2005 |
Current U.S.
Class: |
606/205 |
Current CPC
Class: |
A61F 2002/3008 20130101;
A61F 2002/4628 20130101; A61F 2002/30828 20130101; A61F 2/4611
20130101; A61F 2/447 20130101; A61F 2250/0036 20130101; A61F
2002/30879 20130101; A61F 2002/30593 20130101; A61F 2002/30261
20130101; A61F 2002/30892 20130101; A61F 2002/30266 20130101; A61F
2002/4622 20130101; A61F 2002/2835 20130101; A61F 2250/0098
20130101; A61F 2002/30777 20130101; A61F 2230/0082 20130101; A61F
2/442 20130101; A61F 2002/30324 20130101; A61F 2002/30845
20130101 |
Class at
Publication: |
606/205 |
International
Class: |
A61B 017/56 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 9, 1999 |
FR |
99 09122 |
Claims
We claim:
1. Manipulation forceps for an implant, the implant being in the
form of a cage that is generally in the shape of a rectangular
block-having at least two sagittal walls substantially parallel to
a sagittal plane and interconnected at least by an anterior
transverse wall and by a posterior transverse wall substantially
parallel to a frontal plane, the cage being provided with two
housings extending substantially facing each other in a frontal
direction substantially perpendicularly to the sagittal plane of
the cage, the forceps comprising two branches movable relative to
each other and each provided with an insert-engaging jaw, each jaw
being provided with a radial stud extending in line with the other
radial stud and suitable for being moved towards the other stud so
as to be engaged in a respective housing formed in the implant.
2. Manipulation forceps according to claim 1, wherein the jaws are
arranged to present antirotation means complementary to means
provided on the cage so as to enable the cage to be prevented from
moving relative to the forceps.
3. Manipulation forceps according to claim 2, wherein each jaw
includes, as its complementary antirotation means, an arm which is
provided at its end with a radial stud and which is designed to be
engaged, at least in part, in a groove formed in a sagittal wall
and extending from the housing to the external face of the anterior
wall.
4. Manipulation forceps according to claim 1, wherein each jaw is
provided with a stop abutment for coming into contact against the
external face of the anterior transverse wall of the cage when the
studs are engaged in the housings so as to transmit forces exerted
on the forceps.
5. Manipulation forceps according to claim 4, wherein each stop
abutment is arranged on a jaw so as to come into contact with the
external face of the anterior transverse wall of the cage
substantially in line with the sagittal walls.
6. Manipulation forceps according to claim 1, wherein the jaws are
urged towards each other by the branches.
Description
TECHNICAL FIELD
[0001] The present invention relates to an intersomatic implant for
insertion into the disk space defined between two adjacent
vertebrae, in order to restore an appropriate height between the
vertebrae and in order to allow bone fusion to take place between
said adjacent vertebrae.
[0002] More precisely, the invention provides an intersomatic
implant of the cervical type, for insertion into the disk space
defined between two adjacent cervical vertebrae.
PRIOR ART
[0003] In the state of the art, it is known to insert an
intersomatic implant into the disk space between defined between
two adjacent cervical vertebrae. Numerous embodiments of such
intersomatic implants are proposed in the prior art. For example, a
known cervical intersomatic implant is in the form of a cage
comprising two sagittal walls interconnected by a anterior
transverse wall and by a posterior transverse wall. Between them,
the walls define an open volume for receiving a bone-filler
substance for encouraging bone fusion between the two
vertebrae.
[0004] In general, it can be assumed that inserting an implant of
the above-described type into the disk space between two adjacent
vertebrae is liable to lead to the vertebrae being incorrectly
positioned relative to each other. This means that it is not
possible to obtain good bone reconstitution between the vertebrae
concerned.
[0005] The invention thus seeks to remedy the above-specified
drawbacks by proposing an intersomatic implant adapted to comply
better with the anatomy of the spinal column.
SUMMARY OF THE INVENTION
[0006] To achieve such an object, the intersomatic implant is
designed to be inserted into the disk space defined between two
adjacent vertebrae, namely an overlying vertebra and an underlying
vertebra, for the purpose of reestablishing the anatomic space
between the vertebrae, the implant being in the form of a cage that
is generally in the shape of a rectangular block having at least
two sagittal walls substantially parallel to a sagittal plane and
interconnected at least by an anterior transverse wall and by a
posterior transverse wall extending substantially parallel to a
frontal plane, the walls defining between them an open volume for
bone filler and presenting rims extending on one surface to define
a first transverse face and on the opposite surface to define a
second transverse face.
[0007] According to the invention, the implant comprises:
[0008] a first transverse face presenting in the sagittal plane a
convex profile congruent with the sagittal anatomic profile of an
overlying vertebra; and
[0009] a second transverse face presenting in the frontal plane a
convex profile congruent with the frontal anatomic profile of an
overlying vertebra.
[0010] The invention also seeks to provide an instrument for
manipulating such a cage, enabling the drawbacks of known
manipulation instruments to be remedied. It is known to provide two
holes in the anterior wall of a cage so as to enable two fingers
presented by a manipulation instrument to be engaged therein.
Unfortunately, while the instrument is manipulating the cage, there
is a risk of the cage becoming separated from the instrument, and
of it becoming impossible to withdraw the implant after it has been
put into place.
[0011] Another object of the invention is thus to provide an
instrument for manipulating a cage in the general sense, regardless
of whether it is cervical and/or lumbar, and adapted to hold the
implant safely and reliably while it is being put into place or
repositioned.
[0012] To achieve such an object, the manipulation instrument of
the invention is a forceps for an implant in the form of a cage
generally in the shape of a rectangular block comprising at least
two sagittal walls substantially parallel to a sagittal plane and
interconnected at least by an anterior transverse wall and by a
posterior transverse wall substantially parallel to a frontal
plane, the cage being provided with two housings extending
substantially facing each other in a frontal direction
substantially perpendicularly to the sagittal plane of the cage,
the forceps having two branches movable relative to each other and
each provided with an insert-engaging jaw.
[0013] According to the invention, each jaw is provided with a
radial stud extending in line with the other radial stud and
suitable for being moved towards the other stud so as to be engaged
in a respective housing formed in the implant.
[0014] Various other characteristics appear from the following
description given with reference to the accompanying drawings which
show embodiments and implementations of the invention as
non-limiting examples.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a perspective view of an embodiment of an implant
in accordance with the invention.
[0016] FIG. 2 is a front view of an implant seen substantially
along arrows f.sub.2 of FIG. 1.
[0017] FIG. 3 is a sagittal view of an implant seen substantially
along arrow f.sub.3 of FIG. 1.
[0018] FIG. 4 is a plan view of a forceps for manipulating an
implant in accordance with the invention.
[0019] FIGS. 5 and 6 are views on a larger scale respectively from
above and from the side showing the implant-engaging jaws of the
forceps shown in FIG. 4.
[0020] FIG. 7 is a perspective view showing an intersomatic implant
supported by a manipulation forceps in accordance with the
invention.
BEST METHOD OF IMPLEMENTING THE INVENTION
[0021] As can be seen more precisely in FIGS. 1 to 3, an
intersomatic implant in accordance with the invention is in the
form of a cage 1 which is generally in the form of a rectangular
block and is designed to be inserted in the disk space between two
adjacent vertebrae, e.g. cervical vertebrae. The cage 1 has a first
sagittal wall 2 and a second sagittal wall 3 extending
substantially parallel to each other and to a "sagittal" or
"antero-posterior" plane S. The sagittal walls 2 and 3 are
interconnected by an "anterior" transverse wall 4 and by a
"posterior" transverse wall 5 extending parallel to each other and
to a frontal plane F extending perpendicularly to the sagittal
plane S.
[0022] It should be observed that the cage 1 can have one or more
intermediate or mid walls extending substantially parallel to the
sagittal and/or transverse walls. Preferably, connecting fillets 6
are provided between the sagittal walls and the transverse walls
firstly along their internal vertical faces and secondly along
their external vertical faces so as to provide a cage 1 having
rounded corners on its external and internal vertical faces. For
example, the walls 2 to 5 present substantially the same thickness.
Similarly, the height of the anterior transverse wall 4 is greater
than the height of the posterior transverse wall 5 (FIG. 3).
[0023] Internally, the cage 1 presents a volume 7 defined by the
vertical inside faces of the walls 2 to 5 and designed to be filled
with a bone-filler substance for prompting intersomatic fusion. In
the example shown, this volume 7 opens out into a first transverse
face 8 that is on top and into a second transverse face 9 that is
at the bottom. The walls 2 to 5 present, on one surface, rims 10
defining the top transverse face 8, and on the opposite surface,
rims 10' defining the bottom transverse face 9.
[0024] The cage 1 has protuberances or projections 11 formed on the
rims 10 and 10' of the walls 2 to 5 so as to enable the cage to
bite into the underlying and overlying vertebrae. In the preferred
example shown, the protuberances 11 are constituted by ridges
extending parallel to one another and to the frontal plane F.
Naturally, the protuberances can be of different shapes and could
be implemented, for example, in the form of individual spikes or by
ridges forming chevrons. In general, it should be understood that
the top and bottom transverse faces 8 and 9 correspond to the
envelope containing the tips of the protuberances 11.
[0025] According to a characteristic of the invention which is
shown more clearly in FIG. 3, the top transverse face 8 has a
convex profile C.sub.8 in the sagittal plane S which is congruent
with or complementary to the sagittal anatomic profile of an
adjacent or overlying vertebra in the example shown. It should be
understood that the rims 10 of the walls and more precisely the
protuberances 11 defining said top transverse face 8 are arranged
to be inscribed in an envelope whose section in the sagittal plane
S is rounded or convex in shape.
[0026] In a preferred embodiment, the top transverse face 8 is
defined in the frontal plane F by a straight or rectilinear profile
C'.sub.8 (FIG. 2). The rims 10 of the walls 2 to 5 defining the top
transverse face 8 are preferably arranged to be connected to the
outside faces of the walls 2 to 5 via connecting fillets 12.
[0027] According to another characteristic of the invention which
can be seen more clearly in FIG. 2, the bottom transverse face 9
presents a convex profile C.sub.9 in the frontal plane F, which
profile is congruent with or complementary to the frontal anatomic
profile of an adjacent or underlying vertebra in the example shown.
The rims 10' of the walls 2 to 5, and more precisely the
protuberances 11 defining said transverse face 9 are arranged to be
inscribed in an envelope whose section in the plane S is of rounded
shape.
[0028] Furthermore, it should be observed that the bottom
transverse face 9 presents a profile C'.sub.9 in the sagittal plane
that is substantially straight.
[0029] Advantageously, the above-described cage 1 is adapted to
receive at least one, and in the example shown two, radio-opaque
markers 13 incorporated over at least a portion of the height of
the cage in the anterior and posterior transverse walls 4 and
5.
[0030] The above-described cage 1 is particularly adapted to enable
it to be manipulated by manipulation forceps 15 of the kind shown
in FIGS. 4 to 7, the forceps having two branches 16 each provided
at one end with an insert-engaging jaw 17.
[0031] The cage 1 has two housings 20 extending in line with each
other and each adapted to receive a radial stud 21 formed on each
of the jaws 17 of the forceps. In the example shown, the housings
20 are formed in the sagittal walls 2 and 3, being in alignment and
extending in a frontal direction perpendicular to the sagittal
plane S. The housings 20 are preferably located close to the
anterior transverse wall 4. In the example shown, each housing 20
opens out into the two opposite vertical faces of the walls 2 and
3. Naturally, the housings 20 could be provided in the anterior
transverse wall 4 extending in a frontal direction perpendicular to
the sagittal plane S. In this embodiment, it can be observed that
the two housings 20 can be directly in communication with each
other so as to constitute a single bore. The transverse right
section of each housing 20 is adapted to receive a radial stud 21,
and, for example, is substantially elliptical in the example
shown.
[0032] In a preferred embodiment, the cage 1 includes antirotation
means 23 for co-operating with complementary means 24 provided on
the jaws 17 of the manipulation forceps so as to prevent relative
rotation between the cage 1 and the forceps 15 when the forceps are
engaging the insert. In the example shown, these antirotation means
23 are constituted by a groove formed in each sagittal wall 2, 3 to
open out into a corresponding housing 20 and extending therefrom to
the outside face of the anterior transverse walls 4. As shown more
particularly in FIG. 3, each groove 23 is substantially rectangular
in right cross-section.
[0033] As can be seen more clearly in FIGS. 4 to 6, each
insert-engaging jaw 17 is arranged to present complementary
antirotation means 24 in the form of an arm or a bar having a free
end carrying a radial stud 21 lying substantially in alignment with
the other radial stud. Each arm 24 is of cross-section
complementary to that of the groove 23 and is designed to be
engaged at least in part in the groove 23 formed in a sagittal wall
when each of the studs 21 is engaged in a complementary housing 20.
According to a preferred characteristic of the invention, when the
studs 21 are engaged in the housings 20 (FIG. 7), the outside faces
of the jaws 17, i.e. the arms 24, extend substantially in line with
the outside faces of the sagittal walls 2 and 3 so as to limit the
approach path required for installing the cage.
[0034] Engaging the studs 21 in the housings 20 ensures that the
cage is held securely and prevented from moving in translation, and
the co-operation between the arms 24 and the grooves 23 prevents
the cage from moving in rotation, in particular in a frontal
direction. This ensures that the cage is completely prevented from
moving relative to the jaws 17. It should be observed that the
antirotation means 23, 24 could be implemented in a different
manner. For example, the housings 20 could be prismatic in shape
for co-operating with studs of complementary shape.
[0035] According to a preferred characteristic, each jaw 17 is
provided with a stop abutment 27 for coming into contact with the
external face of the anterior transverse wall 4 of the cage when
the studs 21 are engaged in the housings 20 so as to transmit
forces that are exerted axially on the forceps. As can be seen more
precisely in FIG. 4 to 6, each stop abutment 27 extends radially
substantially parallel to the adjacent stud 21 which is connected
to the stop abutment 27 via the locking arm 24. Each stop abutment
27 is preferably arranged on the jaw 17 so as to come into contact
with the external face of the anterior wall of the cage
substantially in line with the sagittal walls 2 and 3. Such a
disposition provides the advantage of enabling pressure forces
exerted on the end 30 of the forceps where the branches 16 join to
be transmitted in such a manner as to facilitate insertion of the
cage between the vertebrae. The branches 16 of the forceps are
preferably made so as to be resilient and urge the jaws 17
permanently towards each other. In this respect, moving the
branches 16 towards each other causes the jaws 17 to move apart
because the branches cross over, whereas releasing the branches 16
automatically causes the jaws 17 to move towards each other.
SUSCEPTIBILITY OF INDUSTRIAL APPLICATION
[0036] The above-described cage 1 is particularly adapted to
complying with the disk space defined between two vertebrae, e.g.
cervical vertebrae. Complying with the anatomy of the
intervertebral disk that is replaced by the cage 1 serves to
encourage bone fusion between the vertebrae and to restore the
static configuration of the spine. Furthermore, the cage 1 is made
particularly simple to put into place by using the manipulation
forceps 15 of the invention. Thus, from an anterior approach path
to the cervical spine, resection is performed on the osteophytes,
the disk is removed, and then the plane faces of the vertebrae are
revivified. Thereafter, a cage 1 can be taken hold of by the
forceps 15 by acting on the branches 16 to move the jaws 17 apart,
then positioning the studs 21 in the housings 20, and then by
acting on the branches so that the jaws 17 move towards each other,
causing the studs 21 to penetrate into the housings 20 and causing
the arms 24 to penetrate into the grooves 23. It should be observed
that the grooves 23 are capable of providing a guidance function
for the studs 21 which are thus brought up to the housings for
insertion purposes. In this position, the cage 1 is held completely
securely relative to the forceps by the studs 21 being engaged in
the housings 20 and by the arms 24 being engaged in the grooves 23,
and also by the abutments 27 coming into contact against the
anterior transverse wall 4. The cage 1 can be inserted into the
disk space, with it being possible to apply thrust force to the end
30 of the forceps, should that be necessary. Pressing the branches
16 together to move the jaws 17 apart enables the studs 21 to be
disengaged from the housings 20 so as to allow the forceps to be
withdrawn.
[0037] The invention is not limited to the examples described and
shown since numerous modifications can be made thereto without
going beyond the ambit of the invention.
* * * * *