(19) g)
`
`Europaisches Patentamt
`
`European Patent Office
`
`Office européen des brevets
`
`lllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllll
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`(11)
`
`EP1 290 985 A2
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`(12)
`
`EUROPEAN PATENT APPLICATION
`
`(43) Date of publication:
`12.03.2003 Bulletin 2003/11
`
`(51) Int 01.7; A61 F 2/06
`
`(21) Application number: 020185093
`
`(22) Date of filing: 16.08.2002
`
`(84) Designated Contracting States:
`AT BE BG CH CY CZ DE DK EE ES Fl FR GB GR
`IE IT LI LU MC NL PT SE SK TR
`
`Designated Extension States:
`AL LT LV MK RO SI
`
`46988 Fuente del Jarro - Valencia (ES)
`
`(30) Priority: 16.08.2001 ES 200101905
`
`(71) Applicant: IoL INDUSTRIAS QUIRURGICAS DE
`LEVANTE S.L.
`
`(72) Inventors:
`- Lopez Casquero, Carlos
`46988 Fuente del Jarro (ES)
`- Sierrra Aparicl, Alfredo
`46988 Fuente del Jarro (ES)
`
`(74) Representative: Koepe, Gerd L., Dipl.-Chem.
`Koepe & Partner,
`Patentanwfilte,
`Postfach 22 12 64
`
`80502 Munchen (DE)
`
`(54)
`
`Intersomatic cage for posterior fusion surgery to the lumbar column and for surgery
`involving the insertion of a transforaminal implant
`
`Intersomatic cage for posterior fusion surgery
`(57)
`of the lumbar column and a transforaminal implant in-
`troducer, formed by a cage (1, 8, 16) with the aim of
`restoring the height of the intersomatic space between
`lumbar vertebrae (1 4) with lateral windows (2) which al-
`lowthe radiological control of bone growth and a vertical
`trough (3), which shape an interior cavity where the
`
`bone graft (5) is housed for the fusion or arthrodesis,
`with teeth in the shape of a saw (6) on the upper and
`lower part to increase the capacity for subjection and
`area of support between the adjacent vertebrae. De-
`scribed is also the introducer (17) made up of a handle
`(18), a bent tube (19) through which a flexible rod (20)
`passes.
`
`
`
`Fig. 1
`
`Printed by Jouve, 75001 PARIS (FR)
`
`MSD 1133
`|PR2013-00506
`|PR2013-00508
`
`
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`EP1290985A2
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`

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`1
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`EP 1 290 985 A2
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`2
`
`Description
`
`Object of the invention
`
`[0001] This invention refers to an intersomatic cage
`for posterior fusion surgery to the lumbar column and
`for surgery involvingthe insertion of atransforaminal im-
`plant, which represents solutions in terms of improving
`the vertebral fusion of the lumbar column within the
`
`scope of the surgical procedures referred to as PLIF
`(Posterior Lumbar interbody Fusion) or TLlF (Transfo-
`raminal Lumbar lnterbody Fusion), by means of:
`
`I) A monobloc intersomatic cage;
`ii) an expansive intersomatic cage;
`iii) a transforaminal intersomatic cage.
`
`[0002] The function of these intersomatic cages is as
`an element acting as a spacer between and holding the
`lumbar vertebrae between which they are placed,
`in
`such a way that they preventtheir collapse and increase
`the initial mechanical rigidity during lumbarfusion. Atthe
`same time, these intersomatic cages serve as a support
`and structural improvement in combination with other
`types of instrumentation, such as bars and platesjoined
`to transpedicular screws or laminar and pedicular
`hooks.
`
`Background to the invention
`
`[0003] The Posterior intersomatic Fusion oithe Lum-
`bar Column or, as it is better known, Posterior Lumbar
`intemody Fusion (PLlF), was initially developed by
`Cioward in the 1940s to treat lumbar pain due to in-
`tervertebrai hernias orthe degeneration of disks, in this
`surgical technique, the central portion of the disk is re-
`moved and replaced by multiple blocks of osseous graft
`from the patient himself or by artificial bone. More re—
`cently, pedicular screws and plats have been used to
`treat the same degenerative conditions.
`In 1988, Dr.
`Steffe recommended the use of these systems of fixing
`using pedicular screws in combination with these grafts,
`with the aim of better distributing the loads with the an-
`terior part of the lumbar column. Nevertheless, prob-
`lems have still arisen with the transplanted bone, such
`as the collapse of the graft due to the insufficient initial
`mechanical resistance and due to biological incompati-
`bility in cases in which artificial bone had been grafted
`Currently, other variants of posterior approach have
`been developed, such as the transforaminal route
`(TLIF),
`in which a posterolateral surgical approach is
`made along a transforaminai route, but which is basical-
`ly the same technique as the PLlF.
`[0004]
`In this day and age, the intersomatic cages, as
`they are described in this invention, resolve a high per-
`centage of diseases related to the dorsolumbar verte-
`bral disks. The principal surgical indications for these
`are:
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`Damage to the disks due to traumatisms, tumours
`or degeneration of the vertebrae, for which decomv
`pression is necessary, as is restoring the original
`height of the intervertebrai space by means of ar-
`throdesis (osseous fusion).
`Chronic lumbago related to the vertebral disks, for
`which all
`the conservative treatments such as
`
`stretching exercises, analgesics, muscular relax-
`ants etc, do not give positive results.
`it is used as an adjunct in transpedicuiar surgery
`and surgery with bars or plates, thereby increasing
`the rigidity of the system implanted.
`
`[0005] The problems that are currently being created,
`and that are in part stili not resolved for the majority of
`implants, are as follows:
`
`-
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`-
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`-
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`incomplete fusion due in part to the actual design
`of the implant.
`Displacement of the dura mater with the conse~
`quent risk of neurological lesions= again due to the
`design of the implant and its instrumentation.
`Radiopaque materials and massive designs that do
`not permit verification, during the post-operative pe-
`riod, of whether a correct osseous fusion exists.
`
`Description of the invention
`
`[0006] With the intersomatic cage for posterior fusion
`surgery to the lumbar column and for surgery involving
`the insertion of an implant, which is the object of this
`invention, it is sought to avoid or to palliate all of these
`difficulties. Forthis purpose, these cages are designed
`with the aim of providing initial mechanical resistance
`prior to fusion, of facilitating fusion through osseous
`growth through the windows that it disposes of in its de-
`sign, into which autoiogous graft (graft from the patient
`himself) is inserted, and finally, of facilitating the post-
`operative foiiow-up of osseous growth through the win-
`dows or holes provided for in its design and/or use of
`radiotransparent materials (materials that permit the os-
`seous growth to be scanned by X—rays), such as for ex-
`ample: PEEK (polyether ether ketone), Carbon Fibre or
`else PEEK—based Composites of Carbon Fibre.
`[0007] The intersomatic cages for lumbar fusion sur»
`gery to which the invention refers are based on a system
`of essentially hollow intersomatic cages that come in
`three variants, all of which perform the same function
`and which are described in further detail below.
`
`MONOBLOCK CAGE
`
`[0008] This monoblock cage is an intersomatic sepa-
`rating device for lumbar column vertebrae. it is used to
`restore the natural height of the disc and is used as a
`bridge for bone fusion. it is composed of a cage with two
`side windows and one vertical window that form the hol-
`
`low space required to hold the bone graft that will form
`
`
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`

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`3
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`EP 1 290 985 A2
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`4
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`the fusion by growing the bone between the adjoining
`vertebrae. lt is an essentially oval-shaped section, thus
`optimising the implants contact with the bone so that it
`adapts to the discs in the subchondral zone of the ver«
`tebrae to be fused. Its distal part is also higherto main—
`tain the natural curvature or lordosis. The distal part is
`rounded to facilitate its implantation without damaging
`nerve roots or soft spots. The top and bottom of the cage
`are equipped with a tilted sawtooth section with the aim
`to: 1) prevent the device from being expelled by a har-
`poon or blocking effect; 2) prevent the vertebrae from
`collapsing as a result of being crushed by increasing the
`surface area of contact with the bone; and 3) preventing
`any movement which impedes the proper growth of the
`bone between the cage and the adjacent vertebrae.
`
`EXPANSION CAGE
`
`[0009] As in the case of the monoblock cage de-
`scribed above, the second type consists of an interso-
`matic separating device for lumbar column vertebrae.
`The applications and advantages are the same, howev-
`er, the aim of this invention is to augment the fastening
`power of the device to the intersomatic space while
`maintaining the curvature or lordosis of the lumbar col-
`umn after the cage expands. its principal advantage
`over the other designs is the ease with which it is im-
`planted, since the height of the distal part of the cage is
`initially lower before it expands once implanted, thus
`making implantation less traumatic.
`[0010]
`it has a sliding washer inside which, in order to
`be applied, once the cage is in position, an instrument
`is used to push the washer against the cage, causing
`the distal end to expand due to the tilt of the lateral win-
`dow, which serves an angulated lateral guide. The lat—
`eral window is also equipped with a stopper orprojection
`that limits the washer's movement and prevents it from
`leaving the cage.
`
`TRANSFORAMlNAL CAGE
`
`[0011] This Transforaminal Lumbar lnterbody Fusion
`intersomatic cage is in the shape of a circumferential
`arch, hollow on both sides and with orifices or threads
`at either end to facilitate introduction, and is equipped
`with a central column or nerve to make the cage more
`rigid. The cage is shaped in the form of a wedge, seen
`from the side, in order to maintain a fixed angle of lor-
`dosis in the vertebrae.
`
`[0012] This cage offers an improvement overthe pre-
`vious two in that only one piece is required per implant,
`ratherthan two, with a single access channel, thus cut-
`ting down on surgical expenses and simplifying the pro
`cedure which in turn reduces the risk of damage to the
`dura mater.
`
`[0013] This invention also involves a device for intro-
`ducing the cage through transforaminal channels be—
`tween two lumbar vertebrae consisting of a bent tube
`
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`with a handle on one end, the inside of which contains
`a flexible threaded rod that fastens the implant (interso-
`matic cage).
`
`Description of the Drawings
`
`[0014] To supplement the description provided here-
`in, and for a better understanding of the characteristics
`of the invention, this description is accompanied by a
`series of figures which represents the following, on an
`illustrative but non—limitative basis:
`
`Figure 1 represents a side view of the final assem-
`bly of a practical execution of the monoblock inter-
`somatic cage to which the invention refers, relative
`to the placement of the cage in the intersomatic
`channel.
`
`Figure 2 represents a rear view of the same assem-
`bly, relative to the placement of two intersomatic
`cages and bone graft from a rear view.
`
`Figure 3 shows a view of the monoblock intersomat-
`ic cage from an isometric perspective.
`
`Figure 4 shows a rear view of the monoblock inter-
`somatic cage.
`
`Figure 5 shows a side view of the monoblock inter
`somatic cage.
`
`Figure 8 shows an overhead view of the monoblock
`intersomatic cage.
`
`Figure 7 represents a side view of the final assem-
`bly of a practical execution of the expansive inter-
`somatic cage to which the invention refers, relative
`to the placement of the cage in the intersomatic
`channel.
`
`Figure 8 represents a rear view of the same assem-
`bly, relative to the placement of two expansive in—
`tersomatic cages and bone graft from a rear view.
`
`Figure 9 shows a view of the expansive intersomatic
`cage from an isometric perspective.
`
`Figure 10 shows a rearview of the expansive inter-
`somatic cage.
`
`Figure 11 shows a side view of the expansive inter-
`somatic cage.
`
`Figure 12 shows a view from an isometric perspec-
`tive of washer in the expansive intersomatic cage.
`
`Figure 13 shows an overhead view of the expansive
`intersomatic cage
`
`

`

`5
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`EP 1 290 985 A2
`
`6
`
`Figure 14 shows a view of the expansive interso—
`matic cage in the expanded position.
`
`Figure 15 shows an isometric perspective of the
`transforaminal intersomatic cage to which the in-
`vention refers.
`
`Figure 16 shows the top, plan and side views of the
`cage shown in the previous figure.
`
`Figure 17 represents a side view of the final assem‘
`bly of a transforaminal intersomatic cage of the in-
`vention in the intersomatic canal.
`
`Figure 18 shows a cross«sectional plan view of the
`introduction instrument of the invention, having a
`transforaminal implant attached thereto.
`
`Figure 19 is an isometric perspective view of the in—
`troduction path for the transforaminal implant.
`Preferred Embodiment of the Invention
`
`[0015] As seen in the attached figures (Figures 1
`through 6) the monoblock intersomatic cage 1
`is re-
`ceived between two lumbar vertebrae 14 (Figures 1 and
`2). The PM F technique provides forthe symmetrical and
`parallel placement of two cages 1 in each intersomatic
`space.
`[0016] This cage comprises side windows 2 and aver-
`tical pass-through window 3, these windows forming the
`recess 4 in which the bone graft 5 will be received for
`fusion, or arthrodesis. it is possible to obtain such graft
`from the patient himself/herself or from a bone bank, or
`to use a synthetic material. The cage 1 is provided with
`serrated teeth 6 at both its upper and lower portions,
`aiming at enhancing the supporting capacity and bear-
`ing surface between adjacent vertebrae 14.
`it is also
`provided with a coupling system 7 on its back part to
`introduce the implant by means of the suitable instru-
`ment. The sectional geometrical design is essentially
`oval shaped, so that it can conform the anatomy of the
`vertebral subcondral disks 14 and keep the natural lor-
`dosis or angulation of the spinal column at lumbar level.
`The correct size will be selected according to the con-
`ditions of each case, all cages having identical geomet-
`rical characteristics so as to fit any intervertebral size.
`In addition they will be based on anthropometric studies.
`[0017]
`Figures 7 through 17 show the geometrical
`characteristics of the expansive intersomatic cage 8 and
`its situation in the surgical field. Like in the case of the
`single block intersomatic cage, two symmetricai cages
`are placed in parallel in the intersomatic space existing
`between two lumbar vertebrae 14 (Figures 7 and 8).
`[0018] This element comprises a cage 8 that is open
`at its front part, and an internal washer 9 previously
`mounted in the inner part of the cage, the washer being
`able to be slid along an inner canal 4 of the cage, which
`
`will be provided with a suitable slope and able to expand
`the cage 8 at the open or front part, by sliding until it
`encounters a butt 15 of the cage. At the same time, the
`washer 9 is guided by some salients or ridges 12 located
`on another vertical window 3 arranged in the cage 8.
`The washer sliding motion 9 is made by the suitable in-
`struments once the cage has been introduced in its final
`position. This cage of the invention is also provided with
`a few serrated teeth 6 on the upper and lower surfaces
`of the cage 8 serving the same purpose as that of the
`monoblock cage. At the same time, there is provided a
`back coupling system 7 to introduce the cage 8 next to
`the washer 9 together.
`[0019] That is, when this cage 8 is at its standing po—
`sition (Figure 11), the height of the open end is smaller
`than that of the closed end. However, when the washer
`9 is made to slide at the open end on its butts 15, the
`heights are inverted, being the height of the open end
`with the washer 9 larger than the height of the cage
`closed end 8. in any case, the height of the open end is
`larger when the washer 9 is present at this end, than
`when said washer is in the opposite end, thus modifying
`the cage angle.
`[0020] The application and functioning are very sim-
`ple. For that purpose, upon identifying the vertebrae 14
`to be intervened by applying the corresponding tech-
`nique, the intersomatic cage is placed between both ver-
`tebrae, with their recess 4 being filled with bone material
`5. When introducing the cage, the coupling system 7 will
`be employed as to have the serrated teeth 6 or harpoon
`make the introduction — but not involuntary removal
`thereof — easier, as these teeth tend to stick into the
`subcondral bone in the presence of removal motion,
`thus enhancing the prosthesis fixation by avoiding ex-
`pulsion thereof.
`is in-
`[0021]
`'As the single block intersomatic cage 1
`troduced in its corresponding place, and because of its
`angles and oval design, it separates the vertebrae 14
`between which it should be placed, so as to foliow the
`general vertebral anatomy, improve the contact surtace
`and therefore, the distribution of the implant loads. in
`addition, it keeps the natural angulation or lordosis of
`the spinal cord at these lumbar levels.
`[0022] The contact between the bone graft 5 and the
`body of the adjacent vertebrae 14 is attained by the side
`2 and upper 3 windows, which helps the osteointegra-
`tion thus enhancing prosthesis fixation and avoiding fail-
`ures. At the same time and thanks to these windows on
`
`the body 1 and in certain cases, because of the material
`used forthese cages, e.g. the PEEK, examination ofthe
`implant is made easier by means of radiographic tech
`niques orthe like. Since they are not radio-opaque ma
`terials, visibility is possible to bettercontrol its evolution.
`[0023] On the other hand, the variant of the expansive
`intersomatic cage has some features of its own in terms
`of structure, as well as some advantages, too. The ap-
`plication method of this cage is the same as that of the
`monoblock cage. in order to place it, the washer 9 is
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`7
`
`EP 1 290 985 A2
`
`8
`
`located in its standing position (Figure 11), so that the
`cage body inclination 8 facilitates introduction in the in-
`tervertebral space. Upon completion, this washer 9 is
`moved into its working position by applying the corre—
`sponding method (Figure 14).
`[0024] The washer 9 is moved along the interior re—
`cess 4, the window 3 serving as a guide, since the sali-
`ents or ridges 12 are located in the inner part so that
`sliding along this window is allowed with no transversal
`movements hindering such sliding motion. At the end of
`this path, there is a stop 15 against which the washer
`stays at its working position, thus avoiding back collapse
`of the cage and the expulsion of the washer itself.
`[0025]
`in this situation, the cage body 8 has changed
`the slope of its inclination by inverting it, so that the spi-
`nal cord angulation or lordosis is achieved once the
`washer 9 has been moved into its final position. This
`cage is also provided with serrated teeth 6 which, like
`the at the monoblock cage, prevent involuntary removal
`because they stick into the vertebra body 14. it is also
`provided with a cavity 4 forthe insertion of bone material
`5, and a window 3 which makes the bone fusion with
`adjacent vertebrae easier.
`[0026] The transforaminal intersomatic cage 16 is a
`cage having the shape of a circumference arch, hollow
`sides, and holes or threads 18 on its ends so as to fa-
`cilitate introduction thereof, it is provided with a central
`column 19 to enhance cage strength.
`[0027] Seen from its side, it its usual working position,
`it consists geometrically of a wedge or trapezium with
`two angled faces and two parallel faces that keep a fix
`lordosis angle (a) in the lumbar vertebrae upon intro-
`duction thereof in the patient. At the same time, frontally,
`in its normal working situation, it is provided with a con-
`vex zone 20 domed at its upper and lower parts for an-
`atomical adjustment to a vertebral body 14.
`[0028] At the same time, the introduction instrument
`17 comprises a tube 21 bent at its end, having a handle
`22 arranged as depicted in Figures 18 and 19. inside
`the tube there is a flexible bar 23 threaded at the curved
`
`end 24 thereof, which will serve the purpose of support-
`ing the implant 1 6. In addition, the instrument is provided
`of a concave surface 25 that matches the implant 16 so
`as to avoid rotation. At the other end of the tube 21 there
`
`is a torsion device or pommel 26 to transmit the torque
`and which allows attachment to the implant.
`[0029] This pommel is integrally to the flexible bar 23
`so that when one tries to attach the implant 16 to the
`instrument 1 7, said implant should be placed making the
`hole 18 face the end of the flexible bar23. Thus a pref~
`erably threaded attachment is obtained, in which by ro-
`tation of the pommel 26 that is integral to the bar, the
`implant 16 is also threaded and attached to the instru‘
`ment17.
`
`Subsequently, all there is to do is piacing this
`[0030]
`implant in its location via transforaminal, between the
`vertebrae 14 and disengage the implant from the intro-
`duction instrument. in order to achieve this, the pommel
`
`26 is being rotated in the opposite direction, thus releas-
`ing said implant. The fact that the end 25 of the tube 21
`is concave, matching the implant, prevents this from me
`tating on itself.
`[0031] Now that the nature ofthis invention and a way
`of putting it
`into practice have been described, we
`should add that changes can be made to the shape, ma-
`terials and arrangement of the invention and its compo-
`nents as long as these alterations do not substantially
`change the characteristics of the invention described in
`the following claims.
`
`Claims
`
`1.
`
`2.
`
`3.
`
`4.
`
`intersomatic cage for posteriorfusion surgery to the
`lumbar column of the type that uses preferably in-
`tersomatic cages (1 , 8) in orderto restore the height
`of the intersomatic gap between the lumbar verte-
`bras (14), characterized in that the cage compris-
`es lateral windows (2) that allow radiological control
`of bone growth and one vertical trough (3) that form
`the hollow inner recess (4) where the bone implant
`(5) is lodged forthefusion or arthrodesis, an implant
`that can come from the patient himself, from the
`bone bank, or can be made from synthetic material;
`while the cage (1, 8) has some saw-shaped teeth
`(6) on its top and bottom side intended to increase
`the holding ability and the support surface between
`the adjacent vertebras (14); in addition, a coupling
`system (7) is available at its back side to introduce
`the implant using the appropriate instrumentation,
`the geometrical design is of an essentially oval pro—
`file in order to couple with the general anatomy im-
`proving the contact area, the load distribution in the
`implant, improving bone fusion and maintaining it-
`self attached to the vertebras (14) by the means of
`saw-shaped or harpoon-shaped teeth (6) that pre-
`vent the expulsion of the implant.
`
`intersomatic cage forposteriorfusion surgery to the
`lumbarcolumn according to claim 1 , characterized
`in that the global profile of the cage is angulated,
`maintaining the lordosis or the natural angulations
`of the intervened lumbar gaps.
`
`intersomatic cageforposteriorfusion surgery to the
`lumbar column according to claim 2, characterized
`in that the cage (8) has a lateral angulated guide
`(11) and another vertical one (3), through which an
`internal washer (9) is slided along.
`
`intersomatic cage for posterior fusion surgery to the
`lumbar column according to claim 3, characterized
`in that the expansive intersomatic cage (8) has a
`protrusion or step (16) forthe fixation of the washer
`(9) inside the cage.
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`9
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`EP 1 290 985 A2
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`lntersomatic cage for posteriorfusion surgery to the
`lumbar column according to claim 4, characterized
`in that the washer (9) has some salients (12) that
`remain lodged inside the trough (3), in a way that it
`will allow sliding along this trough sewing as a
`guide.
`
`12.
`
`parts.
`
`Transforaminal implant introducer of the type that is
`used as a surgical instrument for the implant of in-
`tersomatic cages (16) on a transforaminal route,
`characterized in that the introducer (17) compris-
`es a tube (21) bended at its end, with a handle (22);
`inside the tube there is a flexible rod (23), threaded
`at its curved end (24), which will be used to hold the
`implant (16), and the instrument has a concave sur-
`face (25) at this same end, and at the other end of
`the tube (21) there is a torsion device or pommel
`(26) for the transmission of the torque that enables
`its attachment to the implant, this handle being in—
`tegral part of the flexible rod (23).
`
`13.
`
`introducer according to
`implant
`Transforaminal
`claim 12, characterized in that the concave sur—
`face (25) is congruent with the implant (16) to pre-
`vent its rotation.
`
`lntersomatic cage for posteriorfusion surgery to the
`lumbar column accordingto claim 5, characterized
`in that the angulation of the lateral guide (11) is
`such that the cage (8) adopts a slope when the
`washer (9) is in its initial or rest position, changing
`this slope when the washer is in its working position.
`
`lntersomatic cage for posterior fusion surgery to the
`lumbar column according to claim 6, characterized
`in that the expansive intersomatic cage (8), with the
`washer (9) located in its working position on its pro—
`trusions (15), falls upon the slope in the vertical di-
`rection.
`
`lntersomatic cage for posteriorfusion surgery to the
`lumbar column according to claim 7, characterized
`in that the expansive intersomatic cage (8), with
`washer (9) located in its working position on its pro-
`trusions (15), modifies the slope of the cage (8) in
`the vertical direction ofwidening, wherein the height
`of the open end is larger when the washer (9) is at
`this and than when it is on the opposite end.
`
`lntersomatic cage for posteriorfusion surgeryto the
`lumbar column of the type that preferable uses
`transforaminal cages (16) in order to restore the in—
`tersomatic gap between lumbar vertebras (14),
`characterized in that the cage (16) comprises a
`cage shaped as a circumferential arc, hollow (4) at
`both its lateral parts in order to lodge the bone im-
`plant (5), and orifices or threads (18) at its ends to
`facilitate its introduction; said cage having a central
`column (19) to give the cage greater rigidity; which
`cage, from a lateral view, at its usual working posi-
`tion, has a geometrical shape of a wedge or a has
`pezium with two angulated sides and two parallel
`sides that maintain a fixed angle of the lordosis (a)
`at the lumbar vertebras once introduced into the pa-
`tient.
`
`10.
`
`11.
`
`lntersomatic cage for posteriorfusion surgery to the
`lumbar column according to claim 9, characterized
`in that, viewing this cage (16) trontally in its usual
`working position,
`it has a convex zone (20) in a
`dome shape at its top and bottom parts for anatomic
`adaptation to the vertebral body (14).
`
`lntersomatic cage for posteriorfusion surgery to the
`lumbar column according to claim 9, characterized
`in that the transforaminal cage (16) has saw
`shaped teeth or harpoons (6) at its top and bottom
`
`10
`
`15
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`20
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`25
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`30
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`35
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`40
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`45
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`50
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`55
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