WO2010070444A1

WO2010070444A1 - Articulated intervertebral stabilisation system

Info

Publication number: WO2010070444A1
Application number: PCT/IB2009/007843
Authority: WO
Inventors: Michael Perisic
Original assignee: Medtech Research Sa
Priority date: 2008-12-18
Filing date: 2009-12-18
Publication date: 2010-06-24

Abstract

The invention relates to an articulated intervertebral stabilisation system for stabilising two vertebra, the system comprising a first articulated element (1a) intended for exerting an action on one of the two vertebrae, a second articulated element (1b) intended for exerting an action on the other one of the two vertebrae, and an articulation means arranged to articulate the first element (1a) relative to the second element (1b). The articulation means comprises at least one convex portion (3^bιs) or at least one projection (3a, 3b) arranged on one of the elements (1a, 1b) and matching a concave portion (4^bιs) or a cavity (4a, 4b) arranged on the other one of the elements (1a, 1b). The concave portion (4^bιs) has a substantially conical surface, while the side flanks of the cavity (4a, 4b) ("conical cavity" is used hereinafter to refer to either the concave portion or the cavity) define, at least to a certain depth, a conical or truncated cone-shaped space. The convex portion (3^bιs) or the projection (3a, 3b) ("cone" is used hereinafter to refer to either the convex portion or the projection) has a matching shape, preferably conical, such as to leave a displacement angle (α) between the side flanks of the cone (3^bιs, 3a, 3b) and the conical cavity (4^bιs, 4a, 4b) enabling one of the elements (1a, 1b) comprising the cone (3^bιs _, 3a, 3b) to rotate and/or oscillate relative to the other one of the elements (1a, 1 b) comprising the conical cavity (4^bιs, 4a, 4b).

Description

ARTICULATED INTERVERTEBRAL STABILIZATION SYSTEM

Technical area

The present invention relates to an articulated intervertebral stabilization system for stabilizing at least two vertebrae. More particularly, this system is used in the form of a connecting member for an extradiscal device for instrumenting a segment of the spine by connecting one of the two vertebrae to the other. It can also be used in the form of a disc prosthesis intended to be introduced into the intersomatic space between the upper and lower vertebrae.

Technological background

Certain pathologies of the spine, including degenerative disc and facet diseases, and dislocations of vertebrae, compromise the spinal support capacity and the distribution of the load.

Treatment of these pathologies in their advanced stages involves different stabilization systems using extra-disc implants or disc prostheses.

With regard to extra-discal implants, systems have been developed where the vertebral screws are implanted in adjacent vertebrae and interconnected by connecting members in the form of plates or rods rigidly secured to the vertebral screws. These extra-disc implants are applied in the anterior part of the column, or in its posterior part, on both sides of the spine, or on the sides of the vertebral bodies. These implant systems have significantly improved the treatment of pathologies of the column, creating a distraction effect between the vertebrae of the segment particularly affected by the collapse of the disk or the degeneration of the facets, with the result the decompression of the nerve roots, and the acceleration of the bone fusion of the vertebrae adjacent to each other.

Unfortunately, these rigid systems, by locking the implant in the position of the instrumented segment at the time of the surgery, cause a destabilization of the spine at the level of the instrumented segment, which progressively leads to a degeneration of the disks and facets of the segments adjacent to the instrumented segment. In addition, rigid system instrumentation does not always exclude, or sometimes only marginally reduce, the pain experienced by treated patients. Finally, other negative effects of rigid extra-discal systems are reported, such as the dislocation of the screws, for example in the presence of an insufficiently dense bone, or the rupture of the stems or screw caps, imposing in these cases surgeries. complicated revision.

There are extra-disc stabilization systems introducing mobility into the intervertebral connecting members. WO01 / 39678, US2005 / 0288672, and US2005 / 0131405 describe for example systems providing mobility in flexion and extension by introducing a damper system in the connecting member. The mobility in rotation or lateral bending is provided for example by an articulation between the connecting member and the screw (WO01 / 39678, WO 2007/104024). Systems incorporating flexible connecting members relying on a flexible core have also been disclosed in particular in the publication WO2006 / 096414. In addition, extra-disc systems comprising a ball joint on rigid posterior intervertebral stems are also known (US 7,316,714, US2005 / 0288672). In the case of disc prostheses, although some of them make it possible to maintain intervertebral mobility, or even to increase it, they nevertheless have a destabilizing effect on the vertebral column because of the absence of sufficient constraints imposed on the movements between the treated vertebrae, in particular prosthesis models based on a fixed pivot point. This destabilization of the column causes, as for rigid instrumentations, the degeneration of the disks and facets of the adjacent segments, as well as the appearance or reappearance of pain.

The object of the present invention is therefore to propose novel joints for intra and extra-disc stabilization systems which have the advantage of overcoming the aforementioned drawbacks.

According to the invention, this object is achieved by an articulated intervertebral stabilization system for stabilizing at least two vertebrae. This system comprises a first element intended to exert an action on one of the two vertebrae; a second element intended to exert an action on the other of the two vertebrae and; articulation means arranged to articulate the first element relative to the second element, the articulation means comprising at least one convex part or at least one projection arranged on one of the elements and in correspondence with a concave part or a cavity arranged on the other elements. The surface of the concave portion and at least a portion of the flanks of the cavity are shaped so as to allow the convex portion or protrusion of one of the elements to rotate and / or oscillate in a conical volume. delimited by said surface of the concave portion or said portion of the flanks of the cavity of the other of the elements.

This articulated intervertebral stabilization system may be in the form of a connecting member for an extra-disc device for instrumenting a segment of the vertebral column by connecting one of the two vertebrae to the other or in the form of a prosthesis disc to be introduced into the intersomatic space between the upper and lower vertebrae. These joints are available in multiple configurations, so that the practitioner can adapt the system according to the indication to be treated. These joints can thus be used for the purpose of arthrodesis, where they will offer very low degrees of freedom of movement, so as to promote the quality and speed of fusion and to reduce iatrogenic pain. They can also tend to maintain the mobility of the vertebral segment by a sustainably dynamic support, in which case the configurations will offer greater freedom of movement.

In the following description, when reference will be made to movements of frontal flexion, lateral flexion, or extension, we will speak of movements of the vertebral column of a patient on which the system according to one of the variants of the invention has been implanted. In this case, it will be assumed that the spine is to the left of the figures representing the system and to which the description refers. Moreover, when we speak of sagittal plane, coronal or transverse, these different plans will also refer to the patient on which the system was implanted. Finally, when reference is made to the coronal or transverse plane, we will speak of a plan parallel to one or other of these.

Brief description of the Figures

The characteristics of the invention will appear more clearly on reading a description of several variant embodiments, given solely by way of examples, in no way limiting with reference to the schematic figures, in which:

Figures 1a, 1b and 1c symbolize the concept of a cone arranged in a conical cavity, on which rests the articulation mechanism of the articulated intervertebral stabilization system, in three different positions; Figure 2 shows a perspective view of the articulated intervertebral stabilization system of an extra-discal connecting member according to a first variant of the invention; Figure 2a shows a view of Figure 2 in the coronal plane after an extension movement;

Figure 2b shows a view similar to Figure 2 after a lateral bending motion; Figure 2c shows a view similar to Figure 2 after a frontal flexion movement;

3 shows a perspective view of the articulated intervertebral stabilization system of an extra-discal connecting member according to a second variant of the invention; Figure 3a shows a section of Figure 3, in the sagittal plane;

Figure 3b shows a view similar to Figure 3a after an extension movement;

Figure 3c shows a view similar to Figure 3a where the system has two flexible components; Figure 4 shows a perspective view of the articulated intervertebral stabilization system of an extra-discal connecting member according to a third variant of the invention;

Figure 5 shows a section, according to the sagittal plane, of the articulated intervertebral stabilization system of an extra-discal connecting member according to a fourth variant of the invention;

Figure 6a shows a section, according to the sagittal plane, of the articulated intervertebral stabilization system of an extra-disc connecting member according to a fifth variant of the invention;

Figure 6b shows a view similar to Figure 6a after a slight forward flexion movement;

Figure 6c shows a view similar to Figure 6a after a more pronounced frontal flexion movement;

Figure 7a shows a section along the sagittal plane of the articulated intervertebral stabilization system of an extra-disc connecting member according to a sixth variant of the invention;

Figure 7b shows a view similar to Figure 7a after an extension movement; Figure 7c shows a view similar to Figure 7b of another example of the system;

8 represents a section, according to the sagittal plane, of the articulated intervertebral stabilization system of an extra-discal connecting member, according to a seventh variant of the invention;

9 shows a section, according to the sagittal plane, of the articulated intervertebral stabilization system of an extra-discal connecting member, according to an eighth variant of the invention;

Figures 10a and 10b show a section along the sagittal plane Ie, the stabilization system intervertebral articulated a connecting member according discal a ^9th embodiment of the invention after movement of extension respectively and front flexion;

Figures 11a and 11b show a section along the sagittal plane, the articulated intervertebral stabilization system of a connecting member according to an extra-discal io ^th embodiment of the invention after movement of extension respectively and front flexion ;

Figures 12a, 12b and 12c show a section along the sagittal plane, the articulated intervertebral stabilization system an extra-discal connecting member according to ^{the II} variant of the invention; Figures 13a and 13b show a perspective view of the articulated intervertebral stabilization system of an extra-discal connecting member according to a ^2nd variant of the invention

Figure 13c shows a section along the sagittal plane of Figure 13b; Figure 14 is a perspective view of a sacral grip incorporating the articulated intervertebral stabilization system according to a ^third variant of the invention;

Figure 15 is a perspective view of an extra-disc junction member including the articulated intervertebral stabilization system according to a ^fourth variant of the invention;

Figure 15a is a cross-sectional view of the articulated intervertebral stabilization system of Figure 15; Figure 15b shows a view similar to Figure 15a according to another example;

Figure 16 shows a perspective view of a disc prosthesis having the stabilization system intervertebral articulated according to a 15 ^th embodiment of the invention;

Figure 17 shows a section along the sagittal or coronal plane, of a disc prosthesis having the stabilization system according to one intervertebral articulated I6 ^th embodiment of the invention;

Figure 18 shows a perspective view of a disc prosthesis having the stabilization system according to one intervertebral articulated I7 ^th embodiment of the invention;

Figure 18a is a schematic view of a cross-section of the cone and cavity of Figure 18;

Figure 19 shows a section along the sagittal or coronal plane, of a disc prosthesis having the stabilization system according intervertebral articulated I8 ^th embodiment of the invention;

Figures 20a, 20b and 20c show a section along the sagittal or coronal plane, of a disc prosthesis comprising the intervertebral stabilization system articulated along a ig ^th embodiment of the invention when the prosthesis is located respectively in a first, second and third position;

Figure 21 shows a section along the transverse plane, the articulated intervertebral stabilization system of a disc prosthesis according to a 20 ^th embodiment of the invention; Figure 21a symbolizes the different movements of the articulated system of Figure 21;

Figure 22a and 22b show a section along the sagittal or coronal plane, of a disc prosthesis having the stabilization system intervertebral articulated according to a 21 ^th embodiment of the invention when the prosthesis is located respectively in a first and second position;

Figure 22c shows a cross section of Figure 23a along the transverse plane; 23 shows a perspective view of a disc prosthesis comprising the articulated intervertebral stabilization system according to a 22 ^th variant of the invention;

Figs. 23a and 23b show a sagittal or coronal sectional view of the disc prosthesis of Fig. 23 when the prosthesis is in a first and second position respectively;

Figure 24 shows a section, in the sagittal or coronal plane, of a disc prosthesis comprising the articulated intervertebral stabilization system according to a 23 ^th variant of the invention. Figures 25a, 25b and 26a, 26b show a cone shape that can be substituted for the cone of certain variants of the invention;

Figures 27, 27a, 27b, 27c and 27d show an intervertebral stabilization system articulated according to a 24 ^th variant of the invention;

Figure 28 shows a side view of a system similar to the 24 ^th embodiment of the invention;

Figure 29 is a view of an intervertebral stabilization system articulated in the coronal plane according to a ^fifth variant of the invention,

Finally, Figure 30 shows a view of an intervertebral stabilization system articulated along a 28 ^th and final embodiment of the invention.

Description of the different variants of the invention

Figures 1a, 1b and 1c symbolize the concept underlying the mechanism of articulation of the intervertebral stabilization system. A cone 3a is arranged inside a conical cavity 4a whose depth P is less than the height H of said cone 3a. The diameter D of a section of the cone 3a in a transverse plane is, on the other hand, smaller than the diameter D 'defined by the flanks of the conical cavity 4a at the same plane in order to leave a deflection angle α so that the conical cavity 4a can pivot and turn bearing on the tip of the cone 3a about the axis δ. The three different positions of the cone 3a in the conical cavity 4a are illustrated by the symbol at the top of each of the three Figures 1a, 1b and 1c.

According to a first variant of the invention (FIGS. 2, 2a, 2b and 2c) which is based on the above-mentioned concept, the articulated intervertebral stabilization system is integrated with a connecting member of an extra-disc device. This connecting member is composed of a first and a second element in the form of a longitudinal plate 1, articulated with respect to one another. The first and the second longitudinal plate 1, each have at one end a support 2, 2 'on which is arranged a part of the hinge means. The support 2 of one of the two plates 1, has a projection 3a in the form of a cone of revolution (hereinafter cone) intended to be arranged inside a conical cavity 4a located on the support 2 " on the other of the two plates 1, 1. The shape of the cone 3a and of the conical cavity 4a is determined so as to leave a deflection angle α (Figure 2a) between the side walls of said cone 3a and lateral flanks of The supports 2, 2 'are arranged relative to one another so as to allow a clearance L between the first and the second longitudinal plate 1, during movements bringing the two plates 1 closer together. , 1 "along an axis corresponding approximately to the sagittal axis to also allow additional degrees of mobility for lateral flexion and frontal flexion movements (assuming a plate arranged in the anterior part of the spine), and in extension (in the hypothesis is a plate arranged in the posterior portion of the spine). The cone 3a and the conical cavity 4a are oriented along the axis of the segment to be instrumented with the top of the cone 3a directed upwards so that in the bending position, the two supports 2, 2 'pivot one relative to each other around the fulcrum located at the top of the cone 3a carrying with them the plates 1, the. Figures 2a, 2b and 2c show, in the case of two prior plates, the two supports 2, 2 'after a movement respectively of extension, lateral bending and frontal flexion. According to a second variant of the invention as illustrated by FIG. 3, the hinge system as described in the first variant is transposed to a connecting member of an extra-disc device composed of a first and a second a second element in the form of an intervertebral rod 1a, 1b. Each rod 1a, 1b is integral with a support 2a, 2b each respectively comprising the cone 3a and the conical cavity 4a hinge means. A clearance space L is arranged between the first and the second support 2a, 2b (FIGS. 3 and 3a) so as to allow freedom of movement in extension going beyond the differential between the slope of the lateral sides of the cone 3a and of the conical cavity 4a. This is indicated when looking for only a guy effect limiting the frontal flexion movement. Freedom of movement may also be limited by the introduction of an intersomatic cage between the two adjacent vertebral bodies. Figure 3a shows the first and second supports 2a, 2b in a "normal" position in which rotational, lateral and extension movements are possible, but not frontal flexion movements beyond the differential between the slope of the lateral sides of the cone 3a and the slope of the lateral flanks of the conical cavity 4a in this axis. Figure 3b illustrates the first and second supports 2a, 2b after the completion of an extension movement. Figure 3c shows the same connecting member as Figures 3a and 3b, in a frontal flexion position, but with flexible components 6a arranged on one of the supports 2a, 2b so as to dampen the extension movements. These flexible components 6a can have different degrees of rigidity and can be synthetic or natural substance, or even be mechanical (eg a spring). These flexible components can also be applied to other places so as to damp the lateral movements (not shown in the figures), for example by non-rigid circular beads encircling the cone or the sides of the conical cavity or embedded in a circular groove around the flanks of the cone or the conical cavity, or pockets of flexible substance embedded in cells dug in the sides of the cone or the conical cavity. This system according to this variant can be modified to introduce a half-sphere and a corresponding cavity instead of the cone and the conical cavity.

4 illustrates a third variant of the invention wherein the positioning of the cone 3a in the conical cavity 4a is by two pairs of buttresses 5a, 5b arranged diametrically opposite on each of the two supports

2a, 2b articulation means between the two intervertebral rods 1a, 1b. Like the first two variants of the invention, the supports 2a, 2b of this third variant are arranged relative to one another so as to leave a clearance space L to have additional mobility in lateral flexion. and in extension.

FIG. 5 represents a section, along the sagittal plane, of the articulation means between a first and a second element 1a, 1b of a connecting member according to a fourth variant of the invention where the first and the second support 2a , 2b, have pivoted relative to each other in said sagittal plane due to frontal flexion. In this variant, the base of the cone 3a has the shape of a hemisphere which fits a spherical cavity 7 which is arranged on the second element 1b. According to this variant, there is no clearance space between the two supports 2a, 2b along the sagittal axis and the pivoting of the cone 3a is therefore effected in the volume defined by the angle of deflection between the walls. cone and conical cavity, thereby generating a rocking movement of the base of the cone within the spherical cavity 7, which promotes the fluidity of the joint and prevents dislocation of the first and second support 2a, 2b . .

A fifth variant of the invention, as represented in FIGS. 6a, 6b and 6c, consists in integrating a recessed cone 8a between the cone 3a and the conical cavity 4a of the supports 2a, 2b of the means of articulation of the first and second element 1a, 1b of the extra-discal connecting member, to create a double articulation. According to FIG. 6a, which represents the articulation means of a link member in equilibrium, the hollow cone 8a is disengaged from the first and second support 2a, 2b. The inner surface of the recessed cone 8a acts as a second conical cavity 4a ¹ , delimiting a first deflection angle α ¹ with the side walls of the cone 3a integrated with the first support 2a, whereas the outer surface of the recessed cone 8a delimits a second angle of deflection α ² with the conical cavity 4a integrated in the second support 2b. An elastic means 6b, for example an elastomer coating, occupies the articulation space between the recessed cone 8a and the conical cavity 4a. The tip of the recessed cone 8a preferably rests directly against the bottom of the second conical cavity 4a.

According to Figure 6b, which shows the means of articulation of the extra-discal connecting member after a slight forward flexion movement where the cone 3a has fully tilted against the back side of the recessed cone 8a relative to the patient's coronal plane but where the second deflection angle α ² remains unchanged. Figure 6c shows the system after a more pronounced bending motion where the corresponding surface of the cone 3a still rests against the back side of the recessed cone 8a as in Figure 6b, but where the second deflection angle α ² is also significantly reduced, compressing the elastic means 6b. The latter may be a layer of elastic material of synthetic or natural substance which may have different degrees of rigidity or a mechanical member such as a spring. The interest of such a variant is not only to dampen the movements, but also to modulate the degree of resistance of the system to the movement, depending on the axis and the curve of the movement. A variant of the invention (not shown) consists in also integrating a flexible element, of a different degree of rigidity, in the space of the first angle of displacement α ¹ between the cone 3a and the inner surface of the recessed cone 8a.

FIGS. 7a, 7b and 7c show a section along the sagittal plane of the means of articulation of a first and a second element 1a, 1b of a connecting member of an extra-disc device according to a sixth variant of the invention.

According to this variant, the support 2a of the articulation means of the first element 1a comprises a portion formed of two inverted cones 3a, 3a 'with respect to their base. The support 2b of the articulation means of the second element 1b integrates meanwhile two conical cavities 4a, 4a 'arranged in correspondence with each cone 3a, 3a ¹ of the first support 1a. As shown in FIGS. 7a and 7b, one of the conical cavities 4a, 4a 'is integrated in a mobile carriage 10, which is free to slide in a housing 11 integrated in the second support 2b. An elastic means 6c is arranged in the housing 11 to dampen the movements of the carriage 10. A clearance space L (Figure 7a) is arranged so that in case of patient extension movement as shown in Figure 7b, the 3a cone pointing downwards comes into contact with the carriage 10 and pushes it against the bottom of the housing 11, the carriage 10 being damped by an elastic means 6c. This system therefore allows movements in flexion / extension, and by the two alternative joints that it incorporates, makes possible rotational and lateral bending movements either in the maximum bending position or in the maximum extension position (as authorized by the clearance space of the system). Figure 7c shows a similar system where the first conical cavity 4a is also integrated with a carriage 10 'which is damped by another elastic means 6c. In this case, both the movements in extension and bending are amortized.

Figures 8 to 12c show a section, according to the sagittal plane, articulating means articulated intervertebral stabilization system of an extra-disc connecting member according to several additional variants of the invention.

More precisely, according to a seventh variant of the invention (FIG. 8), the end of the first element 1a has a convex surface 3 ^bιs whose shape is a cone of revolution (hereinafter cone) arranged in correspondence with the end the second element 1b which has a concave surface 4 ^bιs defining a conical cavity. The angle at the apex of the cone 3 ^bιs of the first element 1a is smaller than the corresponding angle of the conical cavity 4 ^bιs so as to leave a 360 ° angle of deflection α between the lateral flanks of the cone. 3 ^bls and the conical cavity 4 ^bιs so that the first and the second element 1a, 1b can rotate and oscillate relative to each other. The second element 1b further comprises at its end a spherical shell 13 with an opening 13 'through which the first element 1a passes, the latter having a spherical component 14 of a nature to match the envelope of said shell 13.

According to an eighth variant of the invention as illustrated in Figure 9, the cone 3 ^bιs is integrated with the second element 1b which has a shell 13 similar to the previous variant while the conical cavity 4 ^bιs is integrated with the first element 1 b.

According to a ninth variant of the invention (Figures 10a and 10b), the articulation means between the first and second elements 1a, 1b are similar to y m ^{^e} t _e _var j _year t _or _allowing in in addition to a displacement of the two elements 1 a, 1b in an opposite direction along the axis of the instrumented segment (corresponding approximately to the sagittal axis of the patient) to allow more flexible flexion and extension movements. Figure 10a shows the hinge in maximum extension position, while Figure 10b shows the same hinge in maximum bending position.

According to a io ^th variant of the invention (Figures 11a and 11b), the articulation means between the first and second elements 1a, 1b are similar to the 7 ^th embodiment of the invention while further enabling a damping of flexion (Figure 11 b) via a component of resilient material 6d of preferably annular shape which is arranged between the base of the cone 3 ^bιs and the upper side of the shell 13.

According to a 11 ^th embodiment of the invention (Figures 12a and 12b), the articulation means of the stabilization system intervertebral between the first and second articulated element 1a, 1b allow a depreciation of not only extension movements (Figure 12a ) but also in frontal flexion (Figure 12b). In this variant, the first element 1a has one end partially spherical which further comprises a concave surface 4 ^bιs conical (hereinafter conical cavity) arranged to cooperate with a conical convex surface 3 ^bιs of a movable member 14 arranged on an elastic means 6e for damping the movements in extension . The elastic means 6e, the movable member 14 and the first element end 1a are mounted in a cylindrical receptacle 13 connected to or integral with the second member 1b. This receptacle 13 is provided with a circular opening 13 'through which the first element 1a passes. A ring 15 is also arranged inside the receptacle 13, one of its two surfaces being profiled to fit the spherical part of the end of the first element 1a, the other of its two surfaces being in contact with a resilient means 6d arranged against the upper wall of the receptacle 13. This elastic means 6d is arranged to dampen the bending movements. Figure 12c illustrates a similar intervertebral stabilization system in which no stress is exerted on frontal flexion movements.

Figures 13a, 13b and 13c show a connecting member of an extra-disc device according to a - | 2 ^nd variant of the invention, the articulation means of the stabilization system intervertebral between the first and second elements 1a, 1b are similar to the n ^th embodiment of the invention except that the connecting member comprises a type of patellar articulation. More specifically, the end 16a of the first element 1a is spherical and rests inside a spherical housing 16b arranged in a movable element 14, which is mounted in a cylindrical receptacle 13 between two elastic means 6e, 6d. In addition, the spherical element 16a is connected to a segment 3a of the first conically shaped element 1a (hereinafter cone). This segment 3a passes through an opening whose flank delimited a truncated cone-shaped cavity 4a (hereinafter conical cavity). The shape of the cone 3a and the conical cavity 4a are determined so as to leave a deflection angle α between the side walls of said cone 3a and the lateral flanks of said cavity 4a. According to a ^13th variant of the invention, FIG. 14 illustrates the articulated stabilization system of the ^10th variant (FIGS. 11a and 11b) transposed to a sacral grip. More specifically, this sacral outlet, which is adapted to be directly screwed into the patient's sacrum, incorporates a first element 1a having a conical portion 3a and a second element 1b in the form of a cylindrical receptacle connected to the base of the sacral outlet. A conical cavity 4a is located at the bottom of the receptacle 1b. The dimensions thereof are determined to allow a deflection L of the first element 1a in the receptacle 1b. Another variant, not shown, consists in applying this principle to a joint comprising a longitudinal element and an occipital socket.

Figure 15a shows an extra-disc connecting member according to a ^14th variant of the invention. According to this variant, the first and second elements 1a, 1b of the intervertebral stabilization system is in the form of a plate, each plate 1a, 1b being intended to be screwed, at one of its ends, against a vertebral body, of to stabilize anteriorly a segment of two adjacent vertebrae. One of the plates 1a, 1b is provided, at the other end thereof, with a structure in the form of "i-ι", the anterior sides of the side walls each having a projection 3a, 3a 'cone-shaped (hereinafter cone), each cone 3a, 3a 'being mounted inside a conical cavity 4a, 4a' arranged on the lateral side of the part of the other of the plates 1a, 1b which is positioned in the structure in the form of "LJ". The cones 3a, 3a 'have an upper height, from their base to their point, to the depth of the conical cavities 4a, 4a' from their edge to their bottom. The cones 3a, 3a 'also have a diameter at their base which is smaller than the diameter of the edge of the conical cavities 4a, 4a'. According to FIG. 15b, which shows a section between the two plates 1a, 1b at their articulation, along the patient's coronal plane, the bottom of the conical cavities 4a, 4a 'juxtapose at a point corresponding to the center of gravity of the patient. one of the longitudinal plates 1a, 1b relative to each other.

In another example illustrated by Figure 15c, a sphere 16a is inserted into the articulation of the connecting member. This sphere 16a is arranged at the junction between the two cones 3a, 3a 'of one of the two plates 1a, 1b, and moves within a spherical housing 16b of a diameter marginally greater than that of the sphere. This housing 16b operates the junction between the two conical cavities 4a, 4a ¹ of the other of the two plates 1a, 1b. The articulation is no longer done on the tips of cones (as in the system illustrated in Figures 15a and 15b), which have more besides, but between the sphere 16a and the housing 16b. The angle of deflection between the walls of the cones 3a, 3a 'and the flanks of the conical cavities 4a, 4a' are only intended here to restrict the movement in the desired degrees of mobility.

According to a 15 ^th embodiment of the invention (Figure 16), the articulated intervertebral stabilization system is integrated with a disc prosthesis designed to be inserted into the interbody space between an upper and lower vertebra. The first element and the second element 100a, 100b each have an upper and lower plate 101a, 101b adapted to bear respectively against the upper and lower vertebra. One of the elements 100a, 100b comprises a protruding cone-shaped projection 3a (hereinafter cone) intended to be arranged inside a conical cavity 4a located on the other of the elements 100a, 100b. The shape of the cone 3a and of the conical cavity 4a are determined so as to leave a deflection angle α between the side walls of the cone 3a and the flanks of the conical cavity 4a so that one of the elements 100a, 100b comprising the cone 3a can rotate and / or oscillate relative to the other of the elements 100a, 100b having the conical cavity 4a. The lower and upper plateaux 101a, 101b of this disc prosthesis can not only be actuated in rotation relative to each other along the sagittal axis, but they can also be oriented according to additional degrees of mobility for the movements. in flexion, lateral flexion and extension, the maximum amplitude of which is determined by this deflection angle α between the cone 3a and the conical cavity 4a.

In order to dampen the movements, corresponding to frontal flexion, lateral bending, extension, or compression of the column spinal, the system, according to a variant i6 ^th (Figure 17) comprises elastic means 6f, such as an elastomer coating, arranged between the walls of the cone 3a and the conical cavity 4a of the one and the other of elements 100a, 100b of the disc prosthesis. The end of the cone 3a and the bottom of the conical cavity 4a may further comprise respectively a sphere 16a and a housing 16b of identical shape (patellar component) in order to distribute the various stresses exerted on the disc prosthesis. The degree of elasticity of the elastic means 6f, may be variable depending on the sector where they are placed, in order to oppose a greater or lesser compressive force along the axis of the movements. The elastic means may be integral with one or both articulated elements 100a, 100b of the prosthesis, in order to contain the rotational movements. In other variants not shown, the walls of the cone 3a and / or the conical cavity 4a may comprise grooves, for example circular, or recesses to incorporate respectively a ring of elastic material or several other flexible components intended to damp the movements of the prosthesis. Each of the components may have specific dimensions, elasticity or rigidity, in order to modulate the mobility resistance of the joint according to the axis of the movements.

The cone is not necessarily a cone of revolution and may have a classical pyramidal shape (square base), a pyramidal shape with a triangular base or an oval or elliptical base cone in order to restrict or guide the degrees of mobility of the cone. system. Thus, Figure 18 illustrates, in a ^I7th variant, a disc prosthesis whose first element 1a comprises a cone 3b of pyramidal shape with three to three faces, and the second element 1b has a conical cavity 4b of identical shape. The base of the cone 3b is an isosceles triangle, the triangle being oriented so that the median through the main vertex is located in the sagittal plane. In this variant, the distance D1 between the edges of the cone 3b and the corresponding edges of the conical cavity 4b is twice as large as the distance D2 between the faces of the cone 3b and the corresponding flanks of the conical cavity (FIG. 18a). This allows a movement twice as wide in the three axes corresponding to the three medians of the triangle. In a variant not shown the triangle is equilateral.

According to a ^18th embodiment of the invention, Figure 19 represents a circular cone whose lateral walls 3c are asymmetrical with respect to an axis μ ¹ perpendicular to the cone base 3c and passing through its apex. According to this figure the flanks of the conical cavity 4c are also asymmetrical with respect to an axis μ ² perpendicular to the base of the conical cavity 4c. This configuration therefore allows, from the equilibrium neutral position, bending movements greater than in extension. The same principle obviously also applies to the classical pyramidal cone (with a square base), the pyramidal cone with a triangular base or the cone with an oval or elliptical base. Of course, in another variant, only the cone or the conical cavity is asymmetrical.

According to I9 ^th variant of the invention (Figures 20a, 20b and 20c), the disc prosthesis comprises articulation means comparable to those of the fifth embodiment (Figures 6a, 6b, 6c). According to FIG. 20a, which represents the articulation means of the disc prosthesis in equilibrium, a movable element, preferably a recessed cone 8b, is arranged so that its vertex rests on the bottom of the conical cavity 4a of the first element 100a which possesses the upper plate 101a proper to bear against the upper vertebra, said hollow cone 8b is also arranged on the cone 3a of the second element 100b which has the lower plate clean to lean against the lower vertebra. The inner surface of the recessed cone 8b acts as a second conical cavity 4a ', delimiting a first deflection angle α ¹ with the side walls of the cone 3a integrated with the first element 1a, whereas the outer surface of the recessed cone 8a delimits a second angle of deflection α ² with the conical cavity 4a integrated in the second element 1 b. An elastic means 6f, for example an elastomer coating, occupies the articulation space between the recessed cone 8b and the conical cavity 4a. The tip of the recessed cone 8b preferably rests directly against the bottom of the second conical cavity 4a. According to Figure 20b, which represents the means of articulation of the disc prosthesis after a slight extension movement where the cone 3a has fully tilted against the rear side of the recessed cone 8b relative to the patient's coronal plane but where the second angle clearance α ² remains unchanged. Figure 20c shows the system after a more pronounced extension motion where the corresponding surface of the cone 3a still rests against the back side of the recessed cone 8b as in Figure 20b, but where the second deflection angle α ² also occurred. significantly reduced, compressing the elastic means 6f. The latter may be a layer of elastic material of synthetic or natural substance which may have different degrees of rigidity or a mechanical member such as a spring. The interest of such a variant is not only to dampen the movements, but also to modulate the degree of resistance of the system to the movement, depending on the axis and the curve of the movement. A variant of the invention (not shown) consists in also integrating a flexible element, of a different degree of rigidity, in the space of the first angle of displacement α ¹ between the cone 3a and the inner surface of the recessed cone 8a.

Different types of cone and cavity can be superimposed between them. It is also possible to combine two types of cone and conical cavity to further accentuate the directional constraints. Thus, the system as illustrated in Figure 21 (20 ^th variant), the first element 1a of the disc prosthesis incorporates a cone 3a which is articulated with a movable part 8c, at least partially recessed, having an inner wall s' resembling a cone-shaped cavity 4a adapted to receive the cone 3a of the element 1a and a pyramidal outer surface (four-sided) adapted to be housed in a pyramidal cavity (four-sided) of rectangular base integrated with the second element 1b of the disc prosthesis. Flexible components 6th,

6f are advantageously interposed on either side of the outer casing of the movable part 8c. As the symbolizes in Figure 21a, the movement is free here in the first degrees of mobility, namely at the articulation between the cone 3a and the conical cavity 4a within the limits of the differential between the slope of cone and conical cavity. The movement is then reduced, in the larger movements, to a single axis, the distance separating the slope of two sides of the pyramid to that of the short sides of the pyramidal cavity of rectangular base. This movement is damped by soft components 6e, 6f. This system can be transposed to a connecting member of an extra-disc device as described in particular in the fifth variant of the invention.

Figures 22a, 22b and 22c represent a further variant of the invention (2i ^th variant) where the intervertebral stabilization articulated system shown is similar to the 20 ^th embodiment (Figures 20a, 20b and 20c), but further includes a system cables and pulleys to exert against-forces movements, in order to dampen or limit movement. According to this variant, FIG. 22a shows a section, along the sagittal plane, of this prosthesis where the base of the moving part 8c is attached to the lower plate 101b of the second element 100b by a cable 110, which runs around a pulley 111 fixed to the first element 100a of the disc prosthesis. The two plates 101a, 101b are here in two parallel transverse planes. Figure 22b shows the same prosthesis after a movement, hypothetically, in extension. This movement causes a movement "M" of the base of the cone to the rear. It also triggers a compression force "Fc" of the two plates 101a, 101b in their posterior part, and a force "Fd" of distraction between the two plates in their anterior part. This force "Fd" separates the pulley 111 from the lower plate integrating the cone 3a and thus exerts a force "Ft" traction on the cable 110, which causes the base of the movable part 8c forward. The base of this piece 8c thus exerts a force "Fp" pressure against the cone, which dampens or limits the movement "M". The pulley 111 can be replaced by blunt contours and the cables can be more or less rigid, to delay or dampen the reaction "Fp". Another way to give play to a cable (rigid or not) is to give it slack, as shown in Figure 22c, which by the way represents a cross-sectional view of the prosthesis disc. According to this variant the second element 100b comprises a cone 3b of pyramidal shape of triangular base.

According to a 22 ^th variant of the invention, shown in FIG. 23, the second element 100b of the disc prosthesis integrates a conical cavity with a triangular base (the cavity can of course be a cone of any shape), the base of this element 100b being movably arranged in an enclosure 125 of the lower plate 101b on a predefined perimeter, along the axes of the movements of the subject. The advantage of this variant is to allow the displacement of the center of gravity "G" of the prosthesis (ie the tip of the pyramid / the bottom of the cavity) to the center of gravity that would naturally be that of the segment with a natural disk , depending on the movement in question. The mechanism of action is as follows: the movements in one axis, are translated by a pressure force exerted by the tip of the pyramid on the pivot (the bottom of the pyramidal cavity) in the opposite axis; the pyramidal cavity being integrated in the mobile base, it moves on the same plane in said opposite axis, in the chamber 125 101b of the lower plate 101b to its rim. The enclosure 125 may be circumscribed by simple flanges or, as shown in FIG. 24, by ledges with overhangs. Movements can be damped by soft components, which can be circular around the entire pedestal or rim of the enclosure, or segmented and placed at specific locations on the curb of the pedestal or enclosure.

Figures 23a and 23b illustrate the aforementioned mechanism of action. Figure 23a shows a sagittal section of the prosthesis when the two trays 101a, 101b and the second element 100b are in equilibrium. Unlike FIG. 23, the enclosure 125 and the flanges are here integrated into the base of the second element 100b. FIG. 23b shows the same prosthesis after a frontal flexion movement: the upper plate 101a pivoting at an angle a forward, pushed the second element 100b behind the distance D. The center of gravity G thus became moved the same distance D, as well as the upper plate 101a (and thus the upper vertebra) relative to the lower plate 101b (and d onc the lower vertebra).

According to a ^23rd embodiment of the invention, Figure 24 shows a disc prosthesis similar to that shown in Figures 23a and 23b wherein the base of the cone 3b is arranged on a base, which is movably mounted in a second enclosure 125 arranged inside the upper plate 101a. The advantage of this variant is based on the mobility of the two pedestals so that the movements of the latter do not lead to one or other of the trays 101a, 101b, which avoids the shifts between the two vertebrae. In this variant, a sphere 16a is arranged at the top of the cone 3b of the first element 100a inside a spherical housing 16b located in the second element 100b.

It goes without saying that certain features of any variant of the invention may be substituted and / or added to certain features of certain other variants. In particular, the base of the cone and the conical cavity may be oval (Figures 25a and 25b) to limit rotational movements, elliptical or pyramidal, this to orient and restrict the axes of mobility. Furthermore, the tip of the cone according to any one of the variants may be spherical (Figure 26a illustrates a sphere arranged at the end of a cone of pyramidal shape) or slightly blunted (Figure 26b), without becoming a sphere.

According to other variants, the articulated intervertebral stabilization system may be in the form of an intervertebral plate composed of at least two elements which are articulated with respect to each other solely in the coronal plane. In these variants, the system comprises a first element 201a; 301a intended to be secured to a first vertebra 200a; 300a; a second element 201b, 301b intended to be secured to a second vertebra 200b; 300b; and articulation means 205, 208; 305, 308 arranged to articulate the first member 201a; 301a with respect to the second element 201b; 301 b in the coronal plane. First and second members 201a, 201b; 301a, 301b each have at one end or near one end a portion whose cross section is substantially rectangular or square, said portion being oriented so as to be able to move in the coronal plane. A projection 205 ^(bls) ; 305 is arranged on the part of one of the two elements 201a, 201b; 301a, 301b while a cavity 208; 308 or base 208 ^a is arranged on the portion of the other of the two elements for receiving said projection 205 ^(bis); 305. The upper part of projection 205 ^(bis) ; 305 is profiled in a circular arc or has a beveled shape, said upper portion being intended to be arranged against the bottom of the cavity 208; 308 or 208 base ^biSl the bottom of the cavity 208; 308 and the base 208 ^bis being beveled or shaped in a circular arc to allow a tilting movement or rotation in the coronal plane of the first element relative to the second element.

More precisely, according to a 24 ^th variant of the invention (FIGS. 27, 27a, 27b, 27c and 27d), an anterior intervertebral plate is composed of a first element 201a, in the form of a plate, intended to be secured to an upper vertebra. 200a, and a second element 201b, also in the form of a plate, intended to be secured to a lower vertebra 200b. The first element 201a has an end adapted to be secured to the upper vertebra 200a by at least one anchoring means 212a, and another curved end 205 in the form of beveled tongue, that is to say a tongue comprising two slopes 206 culminating at a level 207, preferably equidistant from both lateral sides of the tongue 205. The second element 201 b has an end adapted to be secured to the lower vertebra 200b by at least one anchoring means 212b, and another end incorporating a beveled cavity 208, is meant by that the longitudinal sides of said cavity 208 are substantially vertical and merge in the coronal plane and the side flanks 209 are inclined to meet at the bottom of the cavity 208. The beveled tongue 205 at its top level 207 directed upwards, while the beveled cavity 208 at its opening directed down. It is possible to invert the features and integrate the cavity (but pointing upwards) to the first element 201a and the beveled tongue (but pointing downwards) to the second element 201b. The slopes 206 of the tongue 205 are slightly more inclined than the lateral flanks 209 of the beveled cavity 208, so as to allow the tongue 205 to tilt, resting on its main level against the bottom of the cavity 208, on the other hand. other of this point of support, according to the lateral movements. In another variant not shown, the two slopes 206 of the tongue 205 may have different angles on either side of the main level 207, and the same for the two slopes 209 of the lateral flanks of the cavity 208. This allows the print different constraints to lateral movements on both sides of the tilt level.

Figure 27a shows a sagittal sectional view of Figure 27 when the first and second members 201a, 201b are assembled and are each attached to one of the adjacent vertebrae 200a, 200b in their anterior portion by screws 212a, 212b. The intervertebral space is occupied by an intersomatic cage 213, preserving the height of said space. This Figure 27a shows the vertebral segment when the tip 207 of the tongue 205 is pressed against the bottom 210 of the cavity 208 in the event of an extension movement. The intervertebral plate thus performs a guying effect, limiting the movements in extension. The bending movements are possible, but limited on the one hand by the distance L between the two respective edges of the two elements 201a, 201b but also by the distraction force exerted by the cage 213. Of course, if the plate is fixed at the posterior part of the vertebra (not shown), the stay restricts the movements in flexion and not in extension, and for the lateral plates, the movements in lateral flexion, in one of the axes.

Figures 27b, 27c and 27d schematically illustrate the operation of the articulation of the anterior plate in the coronal plane. Figure 27b schematizes the plate with the vertebral segment in extended position constraint i.e. in tension position (guy); the tip 207 of the tongue 205 bears against the bottom 210 of the cavity 208. FIG. 27c schematizes the plate with the vertebral segment in slight bending movement, and it can be seen that the tip 207 of the tongue 205 is is more supported against the bottom of the cavity 208; in this position, lateral bending movements are possible in a natural way (not shown). Figure 27d schematizes the plate with the vertebral segment in the position of stress extension, but also of lateral (left) bending, one of the slopes 206 of the tongue 205 being in abutment against the slope of the corresponding sidewall 209 of the cavity 208 .

It is noted according to Figure 27a that the articulation is configured so that its volume is mainly nested in the intervertebral space, in order to reduce the volume taken on the front of the plate. Of course, other configurations are possible, especially with a prominent articulation. Thus, FIG. 28 illustrates a system similar to the preceding variant, which consists in not providing for the fitting of a tapered tongue in a bevelled cavity, but merely to slide the end comprising a bevelled edge 207bis of a first element 201a in a base of a second element 201b having a beveled shape, the inclination of the slopes of the beveled edge 207bis and the base being determined so as to limit to a certain degree a lateral bending movement. Moreover, the distance L between the apex of the bevelled flange 207bis and the base of the base makes it possible to limit the movements in extension (in the hypothesis of an anterior plate).

According to a 26 ^th embodiment of the invention, Figure 29 shows a system similar to the previous embodiment wherein, instead of a combination of a tapered tongue and a tapered cavity, nesting is between a half-disk 305 tracing an arc of a circle which may be close to 190 °, placed at the end of a first element 301a in the form of a plate, and a circular groove 308 of a marginally greater diameter the diameter of the half-disc 305, placed at the end of a second element 301b. Here, the second element 301b is connected to a median vertebra 300b and has at each of its ends a flange having the circular groove 308 arranged in correspondence with the half-disc 305 of the first and third elements 301a, 301c each connected to an adjacent vertebra 300a, 300c so as to allow lateral movements by sliding of the half-disc 305 in the groove 308 to the extent permitted by the stops 318 at the base of the half, even under a tensioning force (stay). 305. The operation of this joint is close to the system of the previous variant, with the difference that the lateral bending is here by lateral sliding of the half-disc 305 in the groove 308 instead of a tilting of a tip. Bevel at the bottom of a beveled cavity. A deflection in a coronal plane between the half-disc 305 and the groove 308 (defined by L in the other relevant figures) is also given (although not shown, so as to give a certain mobility in frontal flexion movements. Of course, the disk characteristic may be of a fraction greater than or less than a half-disk, and the same for the circular groove.The stops 318 may not be on the same plane, so as to constrain in a differentiated manner the movements The intervertebral plate here covers two vertebral segments, ie three adjacent vertebrae, and of course the half-disks and grooves may have an inverted sense with respect to those illustrated in this Figure. Similarly, the second element 301b of the intervertebral plate may be rigidly secured to the medial vertebra 300b, for example by two vertebral screws 312 or, according to an alternative embodiment (not shown), simply be loosely attached to a single means of anchoring to the vertebra as an axis, so as to allow a lateral rotation of the second member 301b around this axis and so to accentuate the mobility between the two segments of three vertebrae. The system illustrated in Figure 29 may also be applicable mutatis mutandis to the previous variant. The tongue and the half-disc can have ends with straight edges, even for the bottom of the grooves, be they bevel (as shown in Figure 28) or arc.

In another example (not shown) a floor plate to more than one segment of two vertebrae, wherein a first segment is instrumented with the same or similar system to that described in the 24 ^th and 25 Alternatively, the second and segment is instrumented in "topping-off", that is to say that it is intended to remain mobile. Of course all the embodiments and embodiments described for intervertebral plates are also applicable to all other intervertebral connection systems, for example for intervertebral stems.

Finally, according to a 27 ^th and final embodiment of the invention (Figure 30), a first oval-shaped ring 402a is integrated with a first element 401a in the form of interlaced rod with a second oval ring 402b integrated with a second member 401b also in the form of rod This system is a guy, limiting bending movements. However, in the maximum allowed bending position (in the event of a posterior extra-discal device), it nevertheless constitutes an articulation allowing rotational movements, and, more limited, lateral flexion. A clearance space is arranged between the two rings, which allows movements in extension. These movements will be micromovements in case of implantation of intersomatic cages between the two vertebrae of the instrumented segment. In this case, the system promotes the quality and speed of intervertebral fusion. A variant of this invention, not shown, is to replace the rings with two interlaced hooks. Another variant is to replace the rods with plates. Another alternative is to interlace a ring at the end of a longitudinal member to a ring directly integrated into a sacral outlet. Finally, a last variant (not shown) consists in profiling the internal contour of the rings, so that instead of being of oval shape, one or both and / are oblong, even rectangular, so as to limit rotational movements. Similarly, to further accentuate the directional constraints, the section of the rings may be other than round, including close to a square section, or even a diamond-shaped section or half-rhombus.

Claims

An articulated intervertebral stabilization system for stabilizing at least two vertebrae, the system comprising:

a first element (1a) intended to exert an action on one of the two vertebrae; a second element (1b) intended to exert an action on the other of the two vertebrae and;

- Hinge means arranged to articulate the first member (1 a) relative to the second member (1b), the hinge means comprising at least one convex portion (3 ^bιs ) or at least one projection (3a, 3b; 3c) arranged on one of the elements (1a, 1b) and in correspondence with a concave part (4 ^bιs ) or a cavity (4a; 4b; 4c) arranged on the other of the elements (1a, 1b); characterized in that the surface of the concave portion (4 ^bιs ) and at least a portion of the flanks of the cavity (4a; 4b; 4c) are profiled so as to allow the convex portion (3 ^bιs ) or the projection ( 3a; 3b; 3c) of one of the elements (1a, 1b) to rotate and / or oscillate in a conical volume defined by said surface of the concave portion (4 ^bιs ) or by said portion of the flanks of the cavity (4a; 4b; 4c) of the other of the elements (1a, 1b).

2. Articulated intervertebral stabilization system according to claim 1, characterized in that the surface of the concave portion (4 ^bιs ) is conical while the flanks of the cavity (4a; 4b; 4c) (hereinafter referred to as "conical cavity "for one or the other of the concave part or the cavity) define on at least a certain depth a volume in the form of cone or truncated cone, and in that the convex part (3 ^bιs ) or projection (3a, 3b, 3c) (hereinafter referred to as "cone" for one or other of the convex portion or projection) has a complementary shape, preferably conical, in order to leave an angle (α) of clearance between the lateral flanks of the cone (3 ^bιs ; 3a; 3b) and the conical cavity (4 ^bιs ; 4a; 4b; 4c) so that one of the elements (1a, 1b) including the cone ( ^3b , 3a; 3b; 3c) can rotate and / or oscillate relative to the other of the elements (1a, 1b) comprising the conical cavity ( ^4b , 4a, 4b).

3. articulated intervertebral stabilization system according to claim 2, characterized in that the angle (α) corresponds to a value between 1 ° and 40 °.

4. Articulated intervertebral stabilization system according to claim 2, characterized in that the angle (α) corresponds to a value between 2 ° and 20 °.

5. articulated intervertebral stabilization system according to claim 2, 3 or 4, characterized in that the cone (3a) and the conical cavity (4a) are similar to a cone of revolution to obtain a 360 ° travel.

6. articulated intervertebral stabilization system according to claim 2, 3 or 4, characterized in that the cone (3b) and the conical cavity (4b) are similar to a pyramidal shape.

Articulated intervertebral stabilization system according to claim 2,

3, 4 or 6, characterized in that the cone (3b) and the conical cavity (4b) are similar to a pyramidal shape with a triangular base.

8. articulated intervertebral stabilization system according to claim 2 3, or 4 characterized in that the cone (3c) and the conical cavity (4c) has an oval base.

An articulated intervertebral stabilization system according to any one of claims 2 to 8, characterized in that an elastic means (6b, 6f) is arranged in the conical cavity ( ^4b , 4a, 4b, 4c) of the one of the elements (1a, 1b), the elastic means (6b; 6f) being in contact or being intended to bear against one part of the cone (3 ^bιs ; 3a; 3b; 3c) of the other of the elements ( 1b, 1b) when said elements oscillate with respect to each other.

10. Stabilizing System intervertebral joint according to claim 9, characterized in that a hollow conical member (8a, 8b) whose angle at its apex is less than the corresponding angle of the conical cavity ^(4a; 4a 4b; 4c) of one of the elements (1a, 1b) and greater than the angle of the cone (3 ^bιs ; 3a; 3b; 3c) of the other of the elements, is arranged on said cone ( ^3a ; 3a, 3b, 3c).

11. Articulated intervertebral stabilization system according to claim 10, characterized in that the envelope of the hollow conical element (8a, 8b) has the shape of a cone of revolution, a pyramidal cone, a cone pyramidal triangular base or elliptic-based cone.

Articulated intervertebral stabilization system according to any one of the preceding claims, characterized in that the cone (3a, 3b; 3c) comprises at one end a spherical element (16a) arranged inside a spherical housing ( 16b) located at the bottom of the conical cavity (4a; 4b; 4c).

An articulated intervertebral stabilization system according to any one of the preceding claims, characterized in that one of the first and second articulated members (1a, 1b) comprises a receptacle (13) inside which an element is arranged. mobile (14) having the cone

^(3a; 3a; 3b; 3c) or the conical cavity ^(4a; 4a; 4b; 4c) for (e) to be arranged (e) in correspondence with the conical cavity respectively ^(4a, 4a; 4b; 4c) or the cone ^(3a; 3a; 3b; 3c) of the other of the first and second articulated element (1a, 1b).

An articulated intervertebral stabilization system according to claim 13, characterized in that the shape of the movable member (14) and the receptacle (13) are determined to allow further movement of said member (14) to the interior of the receptacle (13) in a particular axis.

Articulated intervertebral stabilization system according to the claim

14, characterized in that an elastic member (6d, 6e) is arranged on either side of the movable member (14) to dampen the movements of the latter in the particular axis.

An articulated intervertebral stabilization system according to any one of the preceding claims in the form of a connecting member for an extra-disc device for instrumenting a segment of the spine by connecting one of the two vertebrae to the other characterized in that the first member (1a) and the second member (1b) are arranged to be connected respectively to one and the other of the two vertebrae, and in that the cone (3 ^bιs ; 3a; 3b; 3c) and the conical cavity (4 ^bιs ; 4a; 4b; 4c) hinge means are respectively arranged at one of the ends of the first and the second element (1a, 1b), or at one of the ends of one of the first and the second element (1a, 1b) and the movable element (14) arranged in the receptacle (13) of the other of the first and second elements (1a, 1b) to allow an articulated assembly of the two elements (1a, 1b) relative to each other.

17. Articulated intervertebral stabilization system according to the claim

15, characterized in that at least one of the first and the second element (1a, 1b) is a rod.

18. Articulated intervertebral stabilization system according to claim 15, characterized in that at least one of the first and the second element (1a, 1b) is a plate.

Articulated intervertebral stabilization system according to claim 18, characterized in that the first and the second element (1a, 1b) is a plate, one of the plates (1a, 1b) being provided with a shaped structure. ¹ LJ "whose front sides of the side walls each comprise a cone (3a, 3a ¹ ), each cone (3a, 3a ') being arranged inside a conical cavity (4a, 4a') located on each side lateral of the other plates (1a, 1b).

20. Articulated intervertebral stabilization system according to claim 17 or 18, characterized in that the articulation means are arranged to allow further movement of the first and the second element (1a, 1b) respectively in a first and a second direction opposite each other along an axis corresponding approximately to the sagittal axis of the patient to allow movements in flexion and extension.

21. Articulated intervertebral stabilization system according to any one of claims 1 to 15 in the form of a disc prosthesis to be introduced into the intersomatic space between one and the other of the two vertebrae (hereinafter upper vertebra) and lower), characterized in that the first element (100a) and the second element (100b) each have an upper and lower plate (101a, 101b) adapted to abut respectively against the upper and lower vertebra.

22. Articulated intervertebral stabilization system according to the claim

21, characterized in that at least one of the trays (101a, 101b) is B2009 / 007843

35

rotatably and / or rectilinearly mounted with respect to the portion of the first and / or second member (100a, 100b) having the cone (3a; 3b; 3c) and / or the conical cavity (4a, 4b, 4c).