CLAbl TO PRIORITY
The present application claims the benefit of U .S. utilitypatent appfication no.
101951,766, Bed September 29,2004, and Erenchpatent applicationno; 04 06211 filed ,
June 9,2004, both disclosures of which, in their entirety, are herein incorporated by
10 refeienoe.
Field Of The Invention
The present invention relates 'to the field of surgery and medical &plants and.
more particularly to devices and methods for restoring human or animil bone anatomy
15 using medical bone implants.
Backsound Of TJie Invention
:I
:I.. Various causes can be at the root of bone compression, inpaFticular bstwporosis
which causes (for example) natural 'vertebral compression under the weight of the
20 individua1,'but also traumas, \$th the two causes occasionally being combined. Subh.
bone compressions can affect the vertebrae but also concern other bones, such as the
radius and the femur, for example.
Several vertebroplasty techniques are kno\vn for effecting a vertebral correction
i.e., to restore a vertebra to its original shape, or a shape similar to the latter. For
25 example, one technique includes the introduction of anhflatable balloon into a vertebra,
then introducing a fluid under pressure into the balloon in order to force the cortical shell
of the vertebra, and in particular the lower and upper vertebral plateaus, to correct the
shape of the vertebra under the effect of the pressure. This technique is known by as
kyphoplasty. Once the osseous cortical shell has been corrected, the balloon is then
5 deflated, and withdrawn from the vertebra in order to be able to inject a cement into the
cortical shell which is intended to impart, sufficient mechanical resistance for the
correction to have a siguificant duration in time.
A notable disadvantage of the kyphoplasty method resides in its numerous
manipulations, in particular inflation, and in the necessity to withdraw the balloon &om
10 the patient's body. Furthermore, the expansion of a balloon is poorly controlled because
the bauoon's volume is mvlti-directional, which often causes a large pressure to be placed
on the cortical shell in unsuitable directions. Such large pressures risks bursting of the
cortical shell, in particular, the lateral part of the cortical shell connecting the lower and
upper plateaus of a vertebra
15 Other vertebral implants exist whichare intended to fill a cavity in a vertebra.
Such implants, however, generally adopt a radial expansion principle obtained by
formation of a plurality of p oints w hich stand normally t o the 1 ongitudinal axis of the
implant under the effect of contraction of the latter. Such implants impose too high a
pressure on individual points which may pierce the material on wbich the points support.
20 Furthermore, similar to whoplasty, very high. pressure can cause bursting of the tissues
or organ walls, such as the cortical shell, for example. Furthermore, the radial exppsion
, ,
of some implants does not allow apartioular expansion direction to be favoured.
25 Embodiments of the present invention reduce the above noted disadvantages and
provide additional advantages over the prior art devices for bone restoration More
y articularly, some embodiments of the present invention include methods for restoration
of human or animal bone anatomy, and include one or more of the following steps:
- jnkoduction, into a bone for restoring, of an expansible implant according to a
single determined expansion plane which is preferably intrinsic to the implant,
- positioning the expansible implant in the bone in order to make the expansion
plane correspond with a bone restoration plane,
5 - opening out the expansible irdplant in the bone restoration plane, and
- injecting a filling material in andlor around the implant.
The method, accordiug to some embodiments of the invention, allows the creation
of a reinforced sfmotwe resulting in a solid structure (i.e., the implant incorporated by a
hardened filling material thanks to the expansion of the implant). Moreover, the filling
10 material can be injected under relatively low pressure since the implant remains in place
which enables the preservation of the dimensions of the corrected bone structure by the
expansion of the implant.
It is another feature of an embodiient of the present invention that an expansible
implant' may be expandedlopened-out in a bone restoration plane to a determined value:
15 between a minimum thickness (e.g., the thichess of the implant before any expansion),
and a maxin~um thickness (e.g., the thickness of the implant after maximum expansion).
Such a feature allows the expansion value of the implant to be controlled, for example,
for a given vertebral correction.
\ Another advantageous feature of an embodiment of the present invention includes
20 the opening out of an expansible implant by opening out a 6rst andlor a second opposite
plate, forming (respectively) first and a second support surfaces for the bone. S uch a
feature allows the pressure which is exerted by the implant on tissues in contact with the
implant to be reduced by increasing the contact or support surface on the tissues.
The length of the implant may also be sized to be substantially equal to at least
25 one of the first and second support surfaces in the bone. Such a featm allows
I
optimization of a ratio of the support length (on the tissues) to the length of the implant.
The closer this ratio is to one, the more the implant will be viable in places requiring a
small length. Moreover, this feature also allows the introduction of a filling material at
low injection pressure. Low injection pressure is preferable so as to avoid having filling
material injected into inappropriate tissues (e.g., such as bloodvessel walls).
In another embodiment of the iuvention, each of the fist and second plates may
form partially cylindrical support surfaces, a portion (or more) of which may be parallel
5 to a longitudinal axis of the expansible implant. A cylindrical (curved) support surface
may spread out the forces that the implant places on tissues.
In another embodiment of the present invention, the opening out said first and
second plates of the implant utilizes one or more supports under the plates. Such a
feature allows a ratio of the length of the support surfaces to the length of the implant to
10 be increased to be as close to one (1) as possible (see above). Furthermore, this feature
allows thrust forces to be more evenly distributed under the plate in order to reduce the
cantilever.
A filler cement which may be injected in andlor around the implant, so as to aid in
compressive load with the implant in bone restoration, include an ionic cement, in
15 particular a phosphocalcic cement, an acrylic cement or a compound of the latter.
Accordingly, the combination of the implant and the cement is not unlike a steel
reinforced concrete structure in the constmction of b~lildings.
In another embodiment of the present invention, an expansible implant for bone
restoration includes a single plane of expansion intrinsic to the implant. The single plane
of expansion corresponding to a bone restoration plane. The implant may also include
first and second opposed plates respectively forming first and a second bearing surfaces ,
for the bone. The ,first and second plaies are positioned to move away from one another
according to the single plane of expansion (e.g., at the time of the expansion of the
implant). The implant may also include first a d second supports for one or more of the
first and second bearing surfaces, and are preferably provided under either or preferably
both plates (respectively). The implant may also include means for controlling expansion
of the implant. Such means may include a material web provided between each support
and a conesponding plate, having a determined thickness.
In other embodiments of the present invention, the means for controlling
expansion controls an expansion value between a minimuin thickness of the implant
before any expansion of the latter and a maximum thickness of the implant after its
maximum expansion.
The implant may also include (preferably) a means for positioning the expansible
implant in bone in order to make the expansion plane of the implant correspond
substantially with a bone restoration plane. Such means may include an engagement
means (e.g., a threaded engagement) allowing angular orientation of the implant about the
5 longitudiual axis and may include one or more flat sut-faces in an end of the implant (for
example) for attachment with an implant canier.
Still another embodiment of the invention is directed to a system for bone
restoration and may include at least one expansible implant having a single plane of
expansion for corresponding to a bone restoration plane (one or more implants may be
used in a single bone to produce amore symmetrical bone restoration; see Fig. 37). The
system may also include a first tube for positioned adjacent an exterior surface of the
bone for restoration and a first rod having a threaded end for affixing into a distal end of
the interior of the bone (the Grst rod may be received within the first tube). The system
may also include a second tube for receiving the first tube therein and a third tube for
receiving the second tube. The third tube may include one or more engagement members
for anchoring the third tube on the exterior surface of the bone. The system may futther
include a drill for establishing an enlarged opening in the side of the bone, which maybe
guided by the first rod. Moreover, the system may Wher include a medical insertion
device for inserting an expansible implant into apatient.
In still yet another embodiment of the invention, a medical insertion device is
disclosed for inserting an expansible implant into a patient. The device may include a
gripping portion, having a central bore, a first tube housed in the central bore and a
10 threaded rod housed in the fust tube which may include a distal end for receiving an
implant for insertion into the patient. The device may also include a handle attached to
the gripping portion andlor the implant canier as well as a gauge for determining an
expansion of the implant.
Still other features, advantages, embodiments and objects of the present invention
will become even more clear with reference to the attached drawings, a brief description
of which is set out below, and the followiug detailed description.
5 BRIEF DESCRIPTION OF THE FIGURES
Fig. 1A illustrates a perspective view of an embodiment of an expansible implant
according to an embodiment of the invention, in a resting position.
Fig. 1B illustrates the example of Fig. IA, in opened-outlexpanded position.
, Fig. 2A illustrates a side view of another embodiment of an expansible implant
10 . according to another embodiment of the invention, in aresting position.
Fig. 2B illustrates the example of Fig. 2A, in opened-outlexpanded position.
Fig. 3 illustrates a lateral view of the example according to Fig. 1A.
Fig. 4 illustrates a view in section according to the line 1-1 of Fig. 3.
Fig. 5 illustrates a view in section according to the line 11-11 of Fig. 3.
15 Fig. 6 represents an end view according to F of the example according to Fig. 1A.
Fig. 7 illustrates a view &om above of the example according to Fig. 1A.
Fig. 8 illustrates a perspective view of a second embodiment of an expansible
implant according to another embodiment of the invention, in aresting position.
Fig. 9 illustrates the example of Fig. 8, in opened-out position.
20 Fig. 10 illustrates a lateral view of the example according to Fig. 8.
Fig. 11 illustrates a view in section according to the line m-m of Fig. 10.
Fig. 12 illustrates a view in section according to the line IV-IV of Fig. 10.
Fig. 13 illustrates a view in section according to the Iine V-V of Fig. 10.
Fig. 14 illustrates aview in section according to the IineVI-VI of Fig. 10.
Fig. 15 illustrates an end view according to G of the example according to Fig. 8.
Fig. 16 illustrates aview fiom above of the example according to Fig. 8.
Figs. 17-29 illustrate schematically the different steps of an embodiment of a
5 kethod for bone restoration according to the invention.
Figs. 30-32 illustrate schematically steps of another embodiment of a method for
bone restoration according to the invention.
Fig. 33 illustrates a perspective view of an implant carrier device for inseiting an
implant into the bone of a patient according to another embodiment of the present
10 invention.
Fig. 34 illustrates a top view of the implant carrier device of Fig. 33.
Fig. 35 illustrates an expansion gauge for the implant carrier shown in Figs. 33
and 34.
Fig. 36 illustrates a chart with expansion values for implants according to the
15 disclosed embodiments using the implant carrier shown in Figs. 33 and 34.
Fig. 37 illustrates the use of a pair of implants according to another embodiment
of the present invention
DBTfiED DESCRIPTION OF THE EMBODIMENTS
20 The expansible implant 1 represented in Figs, 1A to'7 (as well as other
embodiments) may include one or more of the following:
- a single determined expansion plane 2, which may be intrinsic to the implant,
- means 3 for positioning the expansible implant in the bone allowing the expansion
plane to correspond with a bone restoration plane,
- means 4 for opening out the expansible implant in the single expansion pl&e 2,
- means 5 for controlling a determined expansion value, between a
thickness A of the implant before any expansion of the latter and a maximum
thickness B of the implant after its maximum expansion, and
5 - a first 6 and a second 7 opposite.plate which are able to form respectively a first 8
and a second 9 support surface in the bone intended to be moved apart one fiom
the other along the single expansion plane 2 during expansion of the implant 1.
As shown in Figs. 1A and lB, implant 1 may include a cylindrical shape with a
transverse circular exterior section, and can be manufachlred of biocompatible matellat,
10 (for example titanium) into a tubular body 24 using lathe, laser, and/or electro~erosion
manufachuing t echniques (cast manufachukgm ay also b e used). T he implant 1 may
also include a first 20 end and a second 21 end, each respectllly adopting the shape of a
transverse section of the tubular body 24. The ends are preferably intended to be brought
towards one another to allow the opening-outlexpansion of the implant, as represented in
15 Figs. 1B and 2B.
Accordingly, the two ends 20, 21 are connected to each other by a first 22 and
second 23 rectilinear arms, which are parallel when the implant is not opened-out. The
arms may be formed longitudinally in the tubular body 24 -- i.e., able to be folded under
upon ends 20 aud 21 being brought towards one another, which also results in the
20 distancing of first 6 and second 7 opposite plates from the longitudinal axis 10 ofthe
tubular body 24.
Pigs. 2A-2B illustrate an embodiment of the implant which is similar to the
embodiment disclosed in Figs. 1A and lB, but with an additional set of supports (e.g., a
four bar linkage). More specifically, the implant in Figs. 2A-2B includes supports 13.4,
25 13B, 14A, 14B, 15A, 15E, 16A and 16B, two pair for each of the upper and lower plates.
The additional supports may provide finther rigidity for the implant and/or may insure
that plates 6 and 7 open-out in a substaitially parallel and/or even manner.
As represented in Figs. 4-5, in order for arms 22 and 23 to open out in a single
plane 2 (passing through the longitudinal axis 10 of the tubular body 24), the arms 22 and
23 are preferably diametrically opposed. In that regard, arms 22,23 may be formed from
a transverse recess 40 of the tubular body 24, traversing the tubular body throughout, and
extending o ver the length of the tubular b ody b ehveen the two ends 2 0 and 2 1 of the
implant 1. As represented in Fig. 5, the arms, 22,23 connecting the two ends 20 and 21,
5 respectively adopt a transverse section bounded by a citcular arc 26 of the exterior surface
of the tubular body 24. Chord 27 defines the circular arc 26 and may be included in the
waU 25 to form recess 40. The recess 40 may be symmetrical with respect to the
longitudinal axis 10.
Each arm 22, 23 may be divided into thee successive rigid parts, which may be
10 articulated together in conjunction with the ends 20 and 21 as follows (for example).
With respect to the upper arm 22: a fist rigid part 28 is connected at one end to end 20 by
means of an articulation 29. The other end of rigid part 28 is connected to a f h t end of a
second adjacent rigid part 30 by means of an articulation 31. The second rigid pact 30
may be connected at a second end to the third rigid part 32 by means of an articulation 33.
15 The other end of the third rigid part 32 may be connected to end 21 by means of an
articulation 34. Preferably, the articulations 29, 31, 33 and 34 may include one degree of
freedom in rotation, acting, respectively, about axes which are perpendicular to the
expansion plane 2. Preferably, articulations 29, 31, 33 are formed by a thinning of the
waU fonning the arm in the relevant articulation zone, as represented in Pigs. 1A-3 (see,
20 e.g., reference numerals 5 and 81).
Each aim 22, 23 may open out such that the central rigid part 30 moves away
&om the longitudinal axis 10 of the implant pushed by the hvo adjacent rigid parts 28 and
32, when the ends 20 and 21 of the implant are brought one towards the other. As
represented more particularly in Fig. 3, in order to initiate the movement of the in the
25 c o m t direction when the ends 20 and 21 are brought towards the other, it is preferable to
establish a suitable rotation couple of the various parts of the am.
Accordingly, the rigid parts of ends 28,32 of upper arm 22 may be articulated on
ends 20 and 21, respectively, in the low part of the material web forming these rigid parts.
The rigid parts of ends 28, 32 nlay also be articulated on the central rigid part 30 in an
30 upper part of the material web which forms rigid parts 28, 32. The displacement of the
articulations establish a rotation couple on the rigid parts of ends 28 and 32, when a force
is applied to bring the ends 20 and 21 together along the longitudinal axis 10 of the
implant. This displacement tends to make the rigid part 32 pivot towards the exterior of
the implant as aresult of moving the central rigid part 30 away &om the longitudinal axis
10.
5 The lower arm 23 may be constructed in a similar manner as the upper arm and is
preferably symmetrical to the upper arm 22 with respect to a plane which is perpendicular
to the expansion plane 2 passing through the longitudinal axis 10.
Thus, according to some embodiments of the present invention, the articulations
of the upper 22 and lower 23 arms are preferably formed by weakened zones produced by
10 grooves 81. The grooves define a thin web of material (i.e., the thinness of the material at
31, 33) forming the tubular body 24, ?he thickness of which may be determined by the
depth of the grooves 81 (as represented in the figures) in order to allow plastic
deformation of the material without breaking. Specifically, according to one
embodiment, the rigid parts of ends 28 and 32 of the upper arm 22, and their symmetrical
15 ones on the lower arm 23, can adopt a position, termed exkeme expansion, in which the
intended rigid parts are perpendicular to the longitudinal axis 10 of theimplant 1 upon the
ends 20 and 21 being brought towards one another (the latter being opened up until its
maximum expansion capacity), resulting in plastic deformation of the correspondmg
material. The width of the grooves 81 are preferably predetermined to allow a clearance
20 of the parts of the upper and lower anns and also to impart a suitable radius of curvahue
to the webs in order to ensure plastic deformation without ~ p t u roef the material. .
The first 6 and second 7 opposite plates are may be fonned in the upper 22 and
lower 23 arms. With respect to the lipper arm 22, for example, rigid plate 6 may be
formed by the central rigid part 30 and by material extensions (end parts 28 and 32)
25 extending out both sides'ttlereof. In order to produce the rigid plate 6, end parts 28 and
32 are separated ftom the upper arm 22 using a pair of transverse slots 35 and 36 which
extend longitudinally over the length each respective end part (see Figs. 3-4).
Articulations 31 and 33 and end parts 28 and 32 form, respectively, a fist 12 and a
second 13 support for the first 6 plate. The same applies to the second plate 7 by
30 symmetry.
Hence, according to the illustrated embodiment, the first 6 and second 7 plates
may comprise respectively a first 16, 18 and a second 17, 19 cantilever wing, the
respective attaclunent zones of whichwe situated at the level of the first 12, 14 and
second 13, 15 supports. As represented inFigs. 1A-3, the first 16, 18 and second 17, 19
cantilever wings may include a length corresponding substantially to the maximum
displacement value of one of the first 6 or second 7 plates in the single expansion plane 2.
The first 6 and second 7 plates form first 8 and second 9 suppo~t surfaces,
respectively, each having a length which may be substantially equal to the length of the
implant and which may be displaced perpendicularly to the longitudinal axis 10 during
expansion According to one embodiment of the invention, since the implant 1 is formed
in a tubular body 24, the first 6 and second 7 plates form, respectively, curved support
surfaces, which are preferably parallel to the longitudinal axis 10.
The means 3 for positioning the expansible implant in a bone to enable the
expansion plane 2 to correspond with a bone restoration plane, may include an
engagement means which allows for an angular orientation of the implant about
longitudinal axis 10. For example, such means may include flat surfaces 37,38 which are
formed on the oylindrioal surface with a circular section of end 20, which may allow for
rotational engagement of the implant 1. The means 4 for opening out the expansible
implant in a siagle expansion plane 2, may include end parts 28 and 32 of upper arm 22
and the corresponding symmetrical end parts on the lower arm 23, allowing opening out
of the upper 6 and lower 7 plates.
An implant canier 71 (see Fig. 23) may be used to allow the ends 20 and 21 of the
implant to be brought together when placed within the bone. The implant carrier 71, by
supporting end 20 of the implant, for example, allows the end 21 to be pulled toward end
20, or vice-versa (e.g., end 21 being supported and end 20 being pushed toward end 21).
To %at end, the distal end 21, for example, comprises an opening 39 threaded along the
longitudinal axis 10 'in order to allow the engagement of the implant carrier 71, which
includes a corresponding threaded portion. The proximal end 20 may include a bore 80
along the longitudinal axis 10 in order to allow the passage of a core of the implant canier
71 to pass to thedistal end 21.
A control means 5 may be provided by the implant canler which may include a
miltimetric control means for bringing ends 20 and 21 together, preferably by means of
screw-thread engagement, allowing the expansion to be stopped at any moment as a
function of requirements. On the other hand, the control means are also provided by the
5 articulations of the arms 22 and 23, more specifically, by the thickuess of the material
webs (e.g., 31, 33) dehning each am which, deforming in the plastic region, allow the
expansion to substantially preserve a determined opening-up position of the arms, apart
&om elastic s M a g e which is negligible in practice.
The expansion of the plates 6 and 7 of the implant, and their stabilisation once
10 opened up, can be achieved through adaptation of plates 6 and 7 to the bone geometry by
the plates. While in some embodiments of the invention the plates 6 and 7 are opened-out
in a parallel arrangement, other embodiments of the invention allow plates 6 and 7 of the
implant to be opened-out in a non-parallel displacement, if necessary (e.g., as a hction
of the bone anatomy). For example, the expansion of plates 6 and 7 may be non-parallel
15 if the lengths of individual support arms are different. Por example, if supports 12 and 14
are longer than supports 13 and 15 (see Figs. 1A-2B), opening out the implant will force
plates 6 and 7 to progressively angle away from each other. In Figs. 1A-2B, this would
result that plates 6 and 7 at end 21 to be further apart one another then at end 20. AS one
of ordiuary skill in the art will appreciate, depending upon the configuration, only one
20 respective support need be lengthenedtshortened, in order to obtain a particular angle.
Similarly, as shown in Figs. 2A-2C, when the four bar lhkage comprising
supports 12A, 12B, 13A, 13B, 14A, 14B, 15A, 15B, as shown, are equal lengths (i.e.,
length of 12A = length of 13A, length of 12B = length of 13B, etc.), a parallelogram is
results upon expansion of the implant (parallelism is insured between segments AD and
25 BC; see Fig. ZC).' By modifying the lengths of L.1 and L2, the four bar linkage will.not
result in a parallelogram upon expansion, but rather an angle between plate 6 and 7
occurs. The angle formed may also be dependent on how close ends 20 and 21 are dram
near to each other. As the implant is opened-out, the angle progressively increases.
Figs, 8-16 relate to a second embodiment of an expansible implant 101, the
30 elements of which are functionally similar to the CoITeSponding elements of the implant
embodiment illustrated in Figs. 1-7. Moreover, the ccrtesponding features in ~ i g s8.- 16
relating to the embodiment illustrated in Figs. 1-7 include the same reference numerals,
respectively, with the addition of the number 100 and therefore will not be described
fuiher.
The represented implant 101 differs fiom the implant 1 by the absence of the wbg
5 poltion on the plates 106 and 107, as represented more particularly in Fig. 9. Implant 101
includes a parallelogram system 141 on one of the end parts 128 or 132 of each of the
arms 122 and 123. In the illustrated example, the parallelogram system is represented on
end part 128 of upper arm 122, connected to the end 120 and the coxresponding system on
lower arm 123. The pardelogram systems may be used to ensure displacement of the
10 plates of each of the arms 122 and 123, parallel to longitudinal axis t10 of the implant.
As represented in the figures, the end part 128 of the arm 122 (similarly on corresponding
arm 123) is split, as are articulations 131 and 129 (respectively) over the central pad 130
and over the end 120 of the implant in order to form a parallelogram which is deformable
during displacement of the corresponding plate.
15 . The atticulations of the deformable parallelogram 141 may be produced in the
same manner as the other articulations 131, 133, 134 of the arm 122, as represented in
Figs. 8-16. The disclosed geometry as explained above and represented in Figs. 11-14,
establishes force couples on the various pads 129, 130, 132 of the arm. This allows for
the desired displacements when bringing together ends 120 and 121 of the implant 101.
, .
20 In order to obtain a deformable parallelogram 141, the end past 128 of the am is
preferably divided into three longitudinal levers: two lateral levers 142 and a central lever
143, which form two sides of the defosmable parallelogram 141. The two remaining
sides of the parallelogram may be formed by an extension 144 of the central part of the
arm 122, placed in an axis of extension of the central lever 143, and by a double
25 extension 145 of the end 120, extending parallel to the longitudinal axis 110 of the
implant and placed in the axis of extension of the two lateral levers 142 (seeFig. 8).
It is worth noting that arms 122 and 123 may be symmetrical with respect to a
plane which is substantially perpendicular to the plane of expansion 102 passiug through
the longitudinal axis 110 of the implant 101 in order to obtain, during the expansion of
the implant, the displacement of the two plates 106 and 107 in a manner parallel to the
longitudinal axis 110.
one ~estorationE xamples
. .
5 A first example of a method for human bone restoration according to one
. .
embodiment of the present invention using an expansible implant will now be described
' with reference to Figs. 17-29. It concerns, more particularly, a method for bone
.. . . . restoration of a vertebra via a posterolateral route, with fracture reduction. Accordingly,-
. . . the method may include one ormore (and preferably all) of the following steps. One of
. . 10 skill in the & artwill appreciate that the implant according to so embodiments of the present
invention pushes thoughldivides tissues in the interior of the bone so that the bearibg
surfaces of the implant preferably come into contact with the bone tissue for restorakm.
An expansible implant, expansible (preferably) in a single determined plane 2
(intrinsic to the implant) is introduced into a vertebra 60, the shape of which is to be
15 restored. To effect this operation, a rod/piu 61 (e.g., Kirschner pin type) is placed
percutaneously via the posterolateral route so that the threaded end 62 can be a&ed
(e.g., screwed) into the cortical bone 63 opposite the cortical bone 64 which is traversed
by the pin (Fig. 17). The pin 61 is received in a fist dilation tube 65 until an end of the
fist tube 65 contacts (e.g., may be supported) the exterior surface of the cortical bone 64
20 (Fig. 18).
The first dilation tube 65 is received by a second dilation tube 66, until the end of
the second tube 66 comes into contact (e.g., supported by) the exterior surface of the
cortical bone64 (Fig. 19). The second dilation tube is further received by a third dilation
tube 67, which comes into contact (e.g. is supported) on the exterior surface of the
25 cortical bone 64 pig. 20). ~ceth68 on the end of the third dilation tube 67 anchor the
tube in the cortical bone 64.
The first 65 and second 66 dilation tubes, as shown in Fig. 21, are then removed,
leaving only the pin 61 surrounded by tube 67, which are separated from one another by
tubular spacer 68. The proximal cortical bone 64 and cancellous bone 70 is then pierced
by means of a drill 69 (for example) guided by the pin 61, as represented in Fig. 22. In
one embodiment, the cancellous bone is pierced as far as the distal third (approximately),
then the drill 69 may be withdrawn (the pin 61 may be withdrawn as well) .
A proximal end of the implant 1 is removably attached to a distal end of a hollow
5 core (preferably) implant carrier 71 which is then introduced into the core of tube 67, as
, represent,ed in Fig. 23. The implant may be removable affix@ to the'implant carrier via . '
. tbreaded engagement (for example). Within the core of the implant carrier 71, arod 3316 . .
'
' having a.distal end which includes an engagement means to engage. the distal end of the
.. . .. . implant (and:which may also inc111de an expanded proximal end, lqger than a diameter of
.10 . . the rod) may be inserted, Similar tothe aflkation of the implant to the,implant carrier,
. . the engagement means of the rod to the implant my be via threadedengagemeqt.
The implant canier 71, as shown in Fig. 33, includes a handling means 3310 for
cbntrolled movement of the rod relative to the implant carrier (for example). The handing
.nieans may comprise a gripping block 3312, having a central bore through which the
15 - 'implant carrier 71 is positioned and is held in place at least rotationally, but preferably
rotationally and linearly. In that iegard, a proximal end of the gripping member and the
proximal end of the implant carrier are preferably flush. A handle 3314, according 10 one
embodiment of the invention, may be attached to the proximal end of either,or both of the
gripping member and the implant carrier, but is preferably kee to rotate relative thereto in
20 either or both of the clockwise and counter-clockwise directions. In still another
embodiment of the invention, the handle may not be attached to either or both of the
gripping block and implant carrier. The handle may include a center opening which
' preferably includes internal screw threads of a predetermined thread pitch.
The rod 3316, which is received within the implant carrier, preferably includes
25 external threads corsesponding in head pitch to that of handle 3314. A locking device
331 1 slides relative to the gripping block and may include a pin 3321 which ilictionally
interferes with the rod 3316, to lock the rod in place (i.e., no rotational movement).
The threads of the rod are preferably provided at least along a majority of the
length rod. According to one embodiment of the invention, the rod, implant carrier,
30 gripping block and handle may be preassembled. One would insert the threaded distal
end-of tlie rod into anopening in the center of the proximal end of the implant, where it i .!I . . .. . .
then may be received in the correspondingly threaded portion in the center of the distal ..
end of the implant. The distal end.(i.e.; the location of the implant) of the assembly of the - .
implant with the implant carrierhandling means may then be inserted into dilation tube. -
5 67.
Fig. 34 iltustrates another view of the implant carrier, and includes a gauge 3320
tvhicli may be used to indicate the amount of expansion of the implant (e.g., a
determination on the rotation amount of the rod 3316). The gauge may comprise a
window to the md 3316. As show in Fig. 35, according to one embodiment of the
10 invention, the portion of the rod that is visible may not include threads. Rather, this
section of the rod may include markings 3322 which indicate a percentage of expansion.
Additional markings 3324 provided adjacent the window allow a user to gauge the
percentage of expansion ffom the relative movement between the two markings.
Depending upon the predetermined thread pitch and direction of the thread of the
15 rod 3316, rotation of the handle moves the rod 3316 relative to the implant carrier linearly
in a direction. Preferably, the threads are provided on the rod such that clockwise rotation
of the handle moves the rod outward alvay &om an areain which the implant is to eipmd
(the implantation area). For example, for an M5 thread, a pitch of 0.8 mm may be used.
However, one of skill in the art will appreciate that a thread pitch of behveen about 0.5
20 mm and about 1.0 mm (for example) may be used. Fig. 36 is a chart illustrating a no-load
expansion o f an implant according to one of the embodiments ofthe invention b y the
number of turns of the rod for three particular sizes of implants.
Accordingly, in view of the above embodiment, once the implant i s positioned
within the dilation tube and slid do\vn therein, so that it is placed into the interior of the
25 vertebra 60. The implant is preferably positioned such that the single expansion plane 2
corresponds to the desired bone restoration plane (Fig. 24). The position of the implant
may be verified using any known imaging techniques, including, for example, X-ray and
ultrasound.
The handle 3314 is then rotated to '@~ll'' the rod away &om the implantation area.
30 Since the proximal end of the implant is butted up against the implant carrier, and pulling
on the.rod causes the distalend of the implant to move toward the proximal end (or visa- .
versa). This results in the ends of the implant drawing towards each other which opens,
out 'the implant. More specifically, .opposite plates 6 and 7 are opened .out,
advantageously forming, respectively, a first 8 and a second 9 support surface in the
5 vertebra 60, ivhich surfaces may be continuous over their length which may be
substantially equal to the length of the implant 1 (Fig. 25). In the course of the expansion,
control of the reduction of the fiacture
Accordingly, the expansion of the implant in the vertebra is achieved by support
under the plates allowing the t h s t force to be distributed over the length of the plates
10 under the latter. Thus a sufficient length of the plates may be provided while limiting an
excessive dimensioning of the thickness of the latter in order to resist flexion. It will be
appreciated by those of ordinary skill in the art that the implant according to some
embodiments of the invention adopt a ratio of a spatial requirement in length (uexpanded)
to length of elevator plate which is extremely optimjsed, allowing a preferable
15 use of the limited intra-osswus spaces with a view to ftacture reduction, for example.
The rod 3316 may also include, according to one of the embodiments of the
invention, a disengagement means, which may comprise an internal hex on the prox&al
end 3318 of the rod. This may allow one to disengage the rod fiom the implant once the
implant has been opened out. Alternatively, where the handle is not attached to the
20 gripping block andlor implant carrier, the handle codd be counter-rotated (i.e., rotated
such that the rod does not move in a &redion away from the implant) such that it travek
away fiom the flush portion of tile gripping block and inlplant carrier, such that it engages
the proximal end of the rod. Further counter-rotation of the handle (after opening out of
the implant) causes the rod to rotate in the same counter-rotation as the handle, thereby
25 causing the rod to disengage from the implanj. Depending upon the determined thread
pitch, such disengagement can occur in any number of rotations (e.g., less or more than
one rotation). See also Fig. 26
Preferably, after the rod has been removed, a filling material 74 is injected around
the implant. The filling material may comprise, for example, an ionic cement, in
30 particular, a phosphocalcic cement, an acrylic cement or a compound of the latter, vriih a
view to filling in and around the implant. To accomplish this, a needle of the injector 73
. . is slid down tube 67 until the-end of the needle reaches a distal orifice 39 of the implant.1 , - .
(Fig. 27). The fi1Iing material is then injected via the needle. Continued injection-in a :. ..
retrograde manner may be done np to a proximal orifice 64 of the vertebra 60 (Fig. 28).
The needle of the injector may then be withdraw from tube 67 (Fig. 29). . .
5 . A second example of a. .m. ethod according to an embodiment of the invention for . .
restoration of human bone anatomy, will now be described with references to Figs. 30~32:..
This example generally concerns a method for bone restofation of a vertebra .by .a'
~transpedicularro ute, with hcture reduction. . .
. .
The second example is sirpilar to the first and differs &om the 'latter by the
10 penetration route of the implant into tlle~ertebra6 0, which is now accomplishedin a
transpedicular manner (Fig. 30) +Stead of $he posterolateral route used in the fust
method. A s a result, only some steps of the second method have been represented in
Figs. 30-32 in order to show the different route used for the introduction of the implant 1
into the vertebra. For Figs. 30 to 32, elements identical to those of the first method
15 example have the same numerical references, and those figures correspond respectively to
the steps of Figs. 24, 25 and 28 of the first method example. Concerning the step
represented in Fig. 32, the latter differs slightly from Fig. 28 by the position of the needle
. .. of the injector 73, closer to the distal end of the implant iaFig. 32.
It will thus be seen that the invention attains the objects made apparent from the
, .-
preceding description. Since certain changes may be made without departing fiom the'
scope of the present invention, it is intended that all matter contained in the above
description or shown in the accompanying drawings be interpreted as illustrative and not
in a literal sense (and thus, not limiting). Practitioners of the art will realize that the
method, device and system configurations depicted and described herein are examples of
multiple possible system configurations that fall within the scope of the current invention.

I/We claim:
1. A medical insertion device for inserting an expansible implant into a patient
comprising:
a gripping portion, having a central bore
a first tube housed in the central bore;
a threaded rod housed in the f ~ sttub e having a distal end for receiving an
implant for insertion into the patient;
a handle attached to the gripping portion andlor the implant carrier; and a
gauge for determining an expansion of the implant.
2. The device as claimed in claim 1, wherein a proximal end of the gripping
portion and a proximal end of the first tube are flush.
3. The device as claimed in claim 1, wherein the handle is attached to the
proximal end of either or both of the gripping portion and the first tube.
4. The device as claimed in claim 3, wherein the handle is free to rotate relative to
the gripping portion and/or the first tube.
5. The device as claimed in claim 1, wherein the handle includes an opening
having screw threads corresponding in thread pitch to a thread pitch of the threaded
rod.
6. The device as claimed in claim 1, wherein the gauge comprises an opening in
the gripping portion for viewing a portion of the threaded rod.
7. The device as claimed in claim 6, fiuther comprising first markings positioned
adjacent the window associated with second markings provided on a portion of the
threaded rod displayed in the window, wherein rotation of the threaded rod results in
relative movement between the f ~ satnd second markings.