Triangulation arrangement for correcting the spine and spinal osteosynthesis system with such arrangements

Description

TECHNICAL FIELD OF THE INVENTION

[0001] The invention relates to an assembly allowing the straightening of vertebrae, and in particular but not exclusively of lumbar vertebrae by the posterior route, and a spinal osteosynthesis system comprising such assemblies. STATE OF THE ART

[0002] Conventionally, the straightening of the lumbar vertebrae is carried out by means of spinal osteosynthesis systems comprising bone anchoring means, of the pedicle screw type, implanted in successive vertebrae concerned by the straightening, and connected to each other longitudinally by connecting rods or plates via connection means. For example, document US 9,198,696 B1 discloses crossed connectors used to connect bilateral spinal fixation structures, and document US 9,211,145 B2 discloses a method and system for treating spinal deformities.

[0003] However, straightening the vertebrae using existing lumbar spinal osteosynthesis systems encounters several problems, particularly related to the bending and placement of connecting rods.

[0004] In the case of monoaxial pedicle screws, it is indeed necessary to adapt the connecting rods by appropriate curvatures. However, the bending of the connecting rods remains an operation that is not obvious and not very precise, this being all the more difficult when the deformation of the spinal column is significant. In addition, the correction is in fact limited by the curvature given to the connecting rod in combination with the angle of insertion of the screws into the pedicles. Furthermore, in the case of strong correction, the corrective forces that are directly applied to the pedicle screws can affect the quality of the anchoring, and in particular in the case of osteoporotic bone, cause tearing of the pedicle screws.

[0005] In order to overcome these disadvantages of monoaxial pedicle screws, it is known to replace monoaxial screws with multiaxial pedicle screws. However, the use of multiaxial screws is not entirely satisfactory because they require reduction of the vertebrae either by the technique of positioning the patient or by bending techniques of the connecting rod, techniques which are however relatively heavy, long and difficult and do not systematically ensure, like monoaxial pedicle screws, correct straightening of the vertebrae. In addition, the use of multiaxial screws has the counterpart of a loss of correction.

[0006] Thus, whether the pedicle screws used are monoaxial or multiaxial screws, it is particularly difficult to achieve a precise correction in the 3 dimensions (sagittal, coronal, and transverse). Furthermore, correct straightening of the vertebrae cannot be systematically ensured.

[0007] The invention aims to remedy these problems by proposing a straightening assembly, as well as a spinal osteosynthesis system comprising such assemblies, allowing precise sagittal, coronal, and transverse corrections with a significant capacity for these corrections while ensuring satisfactory quality of attachment to the vertebrae. SUBJECT OF THE INVENTION

[0008] To this end, and according to a first aspect, the invention relates to a vertebrae straightening assembly comprising two bone anchoring means intended to be implanted on the same vertebra, a structure for bridging the bone anchoring means between them, said implantable bridging structure comprising a triangulation bar and connection means for connecting the triangulation bar to each of the bone anchoring means, a correction instrument mounted on the triangulation bar, means for locking the triangulation bar on the bone anchoring means by means of the connection means, the triangulation bar thus forming with the bone anchoring means a rigid assembly of triangular shape, and means for adjusting the angular position of the correction instrument relative to the vertebra according to a determined angle.

[0009] The implanted triangulation bar, combined with the convergent position of the bone anchoring means inherent in the very constitution of the vertebra, makes it possible to obtain a rigid, reinforced triangular fixation assembly that is inseparable from the vertebrae. This allows for corrective maneuvers to be carried out in 3 dimensions directly applied to the vertebra on which the assembly is mounted, without risk of damaging the bone anchors. Furthermore, the possibility of adjusting the angular position of the correction instrument in relation to the vertebra on which it is mounted will allow the surgeon to establish a reference point that allows the desired straightening of the vertebra to be achieved simply and easily.

[0010] According to a first configuration of the invention, the connection means comprise the means for adjusting the angular position of the correction instrument.

[0011] Advantageously, the triangulation bar comprises a zone for attaching the correction instrument arranged to ensure a solid attachment in rotation and translation of the correction instrument on the triangulation bar.

[0012] Advantageously, the triangulation bar has a flat part forming the fixing zone.

[0013] According to another configuration, the means for adjusting the angular position of the correction instrument are provided on the triangulation bar.

[0014] In one example, the triangulation bar comprises a zone for attaching the correction instrument arranged to allow at least one movement of the correction instrument on the triangulation bar in the sagittal plane, the attachment zone constituting the means for adjusting the angular position of the correction instrument. According to a particular embodiment, the triangulation bar comprises a notched part forming the attachment zone.

[0015] Advantageously, the grip area is central.

[0016] The connection means comprise two connectors each comprising a first passage zone defining a longitudinal passage axis for the triangulation bar and a second passage zone arranged to receive one of the bone anchoring means, said second passage zone having an oblong shape oriented parallel to the longitudinal passage axis of the first passage zone, the connectors constituting the means for adjusting the angular position of the correction instrument.

[0017] Advantageously, the second passage zone is offset relative to the longitudinal passage axis.

[0018] Advantageously, the first passage zone is shaped to allow the triangulation bar to slide and rotate within it before it is locked onto the bone anchoring means. After locking the triangulation bar onto the two bone anchoring means, the latter form, with the triangulation bar, a rigid triangular fixing assembly with no degree of freedom.

[0019] According to a particular configuration, each connector is in the form of a clamp comprising a part having a C-shaped section extended by two arms respectively comprising an orifice, the orifices of each arm being arranged opposite each other so as to define the second passage zone while the C-shaped section delimits the first passage zone. Advantageously, it may be provided that the arm orifices are arranged to have an axial offset relative to each other. This arrangement makes it possible to obtain greater clamping on the rod due to the shearing effect.

[0020] Advantageously, each bone anchoring means comprises a fixed screw head extended on either side by a lower threaded part for implantation in the vertebra and by an upper threaded part onto which a tightening nut forming the locking means is intended to be screwed.

[0021] Advantageously, the triangulation bar is straight or curved.

[0022] The invention also relates to a connector intended to be implemented with a straightening assembly such as, for example, that described above, the connector being arranged to allow the adjustment of the angular position of a correction instrument. The connector incorporates all of the characteristics described above. In particular, it comprises a first passage zone defining a longitudinal axis of passage of a triangulation bar and a second passage zone arranged to receive a bone anchoring means, which second passage zone has an oblong shape oriented parallel to the longitudinal axis of passage of the first passage zone.According to a particular configuration, the connector is in the form of a clamp comprising a part having a C-shaped section extended by two arms respectively comprising an orifice, the orifices of each arm being arranged opposite each other so as to define the second passage zone while the C-shaped section delimits the first passage zone. Advantageously, it may be provided that the arm orifices are arranged to have an axial offset relative to each other. This arrangement makes it possible to obtain greater clamping on the rod due to the shearing effect.

[0023] The invention also relates to a spinal osteosynthesis system comprising at least two vertebrae straightening assemblies as described above, said assemblies being intended to be implanted on two separate vertebrae and to be connected to each other.

[0024] Advantageously, the system comprises at least one operating instrument connecting the correction instruments of each of the triangulation sets together.

[0025] Also disclosed is a method, not included within the scope of the claims, for straightening vertebrae using two vertebra straightening assemblies as previously described and comprising the following steps: implanting first bone anchoring means in a first vertebra, implanting second bone anchoring means in a second vertebra connecting the first bone anchoring means to each other by means of a first triangulation bar comprising first means for attaching a first correction instrument, said first triangulation bar forming a first implanted bridging structure, connecting the second bone anchoring means to each other by means of a second triangulation bar comprising second means for attaching a second correction instrument, said second triangulation bar forming a first implanted bridging structure, positioning the first and second correction instruments relative to each other at an angle corresponding to the desired sagittal angular correction and locking the first and second correction instruments in position, and,after locking the first and second correction instruments in position, move the first and / or the second correction instrument to position them parallel to each other.

[0026] According to a first embodiment not included in the scope of the claims, the positioning of the first and second correction instruments at an angle corresponding to the desired sagittal angular correction is achieved by pivoting the first and second triangulation bars on the first and second bone anchoring means. The adjustment of the angular position of the correction instruments is made possible by the implementation of means for connecting the triangulation bars to the bone anchoring means, which connection means are arranged to allow, before locking, a multiaxial movement of the triangulation bars on the bone anchoring means. The locking of the first and second correction instruments in position is then achieved by locking the triangulation bars on the first and second bone anchoring means.

[0027] According to another embodiment not included in the scope of the claims, the positioning of the first and second correction instruments at an angle corresponding to the desired sagittal angular correction is achieved by pivoting the correction instruments on their respective triangulation bars via the attachment means of said bars arranged to allow such pivoting movement.

[0028] The installation of the triangulation bars and the positioning of the correction instruments at a defined angle before blocking allows optimal and precise control of the sagittal, coronal and transverse corrections.

[0029] Advantageously, the first and second correction instruments are fixed respectively to the first and second triangulation bar, at the level of the first and second attachment means, prior to the installation of said triangulation bars on the associated bone anchoring means. BRIEF DESCRIPTION OF THE FIGURES

[0030] Other objects and advantages of the invention will appear during the following description, made with reference to the appended drawings, in which: there figure 1 represents a schematic view of a vertebrae straightening assembly according to an exemplary embodiment; the figure 2 represents a partial exploded view of the vertebrae straightening assembly of the figure 1 ; there figure 3 represents a top view of the triangulation bar implemented in the vertebrae straightening assembly of the figure 1 ; there figure 4 represents another example of the realization of the triangulation bar; the figures 5 to 7 represent respectively perspective, top and side views of the connector implemented in the vertebra straightening assembly of the figure 1 ; THE figures 8 and 9represent a detailed perspective view of the straightening assembly, respectively before and after the installation of the tightening nut; Figures 10 and 11 represent a side view of the straightening assembly illustrated in the figures 8 and 10 ; THE Figures 12 to 18b represent the steps of setting up two straightening sets for the straightening of vertebrae; the Figures 19a to 19c show respectively perspective, transverse and posterior views of vertebrae requiring straightening in 3 dimensions, said vertebrae being equipped with straightening assemblies according to the invention; Figures 20a and 20b show the vertebrae illustrated on the Figures 19a to 19c after a transverse rotation correction; the Figures 21a to 21c show the vertebrae illustrated on the Figures 20a and 20b after correction of coronal displacement; figure 22represents a schematic view of a vertebrae straightening assembly according to another exemplary embodiment; the figure 23 represents a partial exploded view of the vertebrae straightening assembly of the figure 22 . DETAILED DESCRIPTION OF THE FIGURES

[0031] In relation to the figures 1 to 11 , an example of an embodiment of a vertebrae straightening assembly 1 according to the invention is described.

[0032] The straightening assembly 1 comprises two bone anchoring means 2 intended to be implanted on the same vertebra 100, a triangulation bar 3 and connection means 4 making it possible to connect the triangulation bar to each bone anchoring means.

[0033] In the illustrated embodiment, the triangulation bar 3 (of circular section in the example) advantageously has an Omega shape in order to follow the shape of the vertebra 100 on which it is mounted. More particularly, it comprises a central part 30 and two end parts 31, 32 respectively linear, said end parts each being connected to the central part by a curved portion.

[0034] In order to straighten the vertebrae using the technique described below, the triangulation bar 3 includes a hooking zone 33 for hooking a correction instrument 10. In the illustrated embodiment, the hooking zone 33 is provided at the central part 30. It is formed of two flats arranged on either side of the bar. They are arranged centrally in the curved part.

[0035] The connection means 4 associated with each anchoring means 2 comprise a connector 5 and a tightening nut 6.

[0036] Each connector 5 comprising a first and a second passage zone 51, 52, the first zone being arranged to receive the end parts 31, 32 of the triangulation bar 3, the second zone being arranged to receive one of the bone anchoring means 2. Advantageously, the second passage zone 52 is offset relative to the first passage zone 51 and defines a longitudinal passage axis perpendicular to the longitudinal passage axis of the first passage zone 51.

[0037] According to an advantageous configuration, the second passage zone 52 is advantageously oblong in shape to allow the fixing of the straightening assembly in a configuration where the triangulation bar 3 and the anchoring means 2 are not perpendicular. In the embodiment described, the angular movement is + / - 15°. Advantageously, the second passage zone 52 is arranged to allow rotation of the connector 5 on the anchoring means 2, and thus allow the adaptability of the triangulation bar when the latter is not perpendicular to the anchoring means 2.

[0038] In the illustrated embodiment, each connector 5 is in the form of a clamp, generally U-shaped, comprising two branches 53, 54 extending opposite and at a distance from each other and, at the level of the origin of the branches 53, 54, a tubular portion 50 of C-shaped section defining the first passage zone 51 for receiving the triangulation bar 3. Each branch 53, 54 of the connector comprises a through-orifice 523, 524 defining the second passage zone 52. Advantageously, the through-orifices 523, 524 respectively have an oblong shape oriented parallel to the longitudinal axis of passage of the first passage zone 51, the through-orifice 523 having a length greater than that of the through-orifice 524. This arrangement of the oblong-shaped orifices 523, 524 has the advantage of allowing the free rotation of the connector 5 on the means of bone anchoring before its blocking.As illustrated in the figures, the second passage zone 52 is offset from the longitudinal passage axis.

[0039] In the illustrated embodiment, the through-holes 523, 524 are arranged coaxially, facing each other. According to an alternative embodiment, the through-holes 523, 524 may be arranged to have a slight offset relative to each other in order to ensure greater clamping pressure on the rod by shearing effect.

[0040] Advantageously, the through-orifice 523 of the upper branch (branch 53) is delimited by an internal bearing surface 523A having a curved shape shaped to receive one of the tightening nuts 6, said tightening nuts 6 each having a base of convex shape capable of cooperating with the internal bearing surface of the through-orifice 523 of the branch 53.

[0041] Advantageously, the first passage zone 51 is shaped to allow the sliding and rotation of the triangulation bar 3 within it before it is locked on the connectors 5 via the clamping nuts 6.

[0042] The connectors just described are thus arranged to form adjustment means which will make it possible to adjust the angular position of a correction instrument mounted on the triangulation bar 3 as will be described later. It may also be provided that the adjustment means are carried, not by the connectors, but by the triangulation bar 3. figure 4 gives an example of a triangulation bar 3 in which the attachment zone 33 has a notch. It is thus possible to adjust the angular position of the correction instrument.

[0043] In the illustrated embodiment, the bone anchoring means 2 are in the form of a pan-head anchoring screw. In the following, we will refer to “bone anchoring means” or “anchoring screws” interchangeably.

[0044] Each anchoring screw 2 comprises a screw head 20 extended on either side by threaded parts 21, 22, the lower threaded part 21 being shaped for implantation in the vertebra, the upper threaded part 22 being shaped to receive one of the tightening nuts 6. Furthermore, the screw head 20 has an upper face 20A of convex spherical shape and, in the lower part, a lateral face 20B having a 6-sided imprint. As will be seen later, the connector 5 is positioned on the associated anchoring screw 2, the lower face of the lower branch 54, of advantageously complementary shape, coming to bear against the upper face 20A of spherical shape of the screw head 20, the latter playing a pivot role during the straightening of the vertebrae.The tightening nut 6, under the application of a tightening torque, causes the branches 50, 51 to move closer to each other, until the triangulation bar 3 is locked in the connector 4 (. figures 8 to 11 ).

[0045] THE Figures 12 to 19b illustrate the installation of two straightening sets 1 as described previously and their implementation for the straightening of vertebrae.

[0046] First of all, the anchor screws 2 of each of the straightening assemblies are placed on the two vertebrae 100, 110 located on either side of the area of ​​the spinal column to be treated ( figure 12 ). Each anchor screw 2 is implanted at the level of one of the pedicles of the associated vertebra (the figures show schematically vertebrae). The anchor screws 2 of each vertebra 100, 110 are implanted so as to converge towards each other.

[0047] The anchoring screws 2 of the same vertebra are then connected to each other with a triangulation bar 3 by threading, through the second passage 52 of each connector 5 equipping the ends of said bar, the upper threaded part 22 of the anchoring screw 2 concerned until the lower branch 54 of the connector 5 comes to bear on the spherical upper face 20A of the screw head 20. This step is carried out using a handling instrument 10 previously fixed on the attachment zone of the triangulation bar 3 ( Figures 13a and 13b). In the illustrated embodiment, the manipulation instrument 10 is intended to also ensure the correction of the vertebrae. It will hereinafter be referred to as the correction instrument 10. In the illustrated embodiment, the correction instrument 10 is formed of an axis 16 provided with a plurality of attachment means 11 intended to allow the attachment of additional instruments, and in particular so-called maneuvering instruments. Advantageously, the attachment means 11 form a ball joint to allow a multi-directional connection with the additional instruments, said ball joint being able to be locked at any time. The correction instrument 10 comprises, at the end opposite the attachment end on the triangulation bar 3, a handle 17.Advantageously, the handle 17 is arranged to have extensions 18 extending on either side of the axis, and advantageously perpendicular to it, in the transverse plane of the vertebrae when the correction instrument 10 is mounted thereon.

[0048] The tightening nuts 6 are then placed on the upper threaded part 22 of the screw head 20 emerging from the connector 5 without however being screwed completely so as not to block on the one hand the movement of the triangulation bar 3 through the connector 5 and on the other hand the movement of the connectors 5 on the anchoring screws 2 ( Figure 13c ).

[0049] The correction instruments 10 are then positioned relative to each other at an angle α corresponding to the sagittal angular correction predetermined by the surgeon, which is generally chosen to obtain optimum sagittal balance for the patient using an angle measuring instrument 15. In the case of an osteotomy, the angular positioning of the correction instruments 10 is chosen to correspond to the desired lordosis angle in the end.

[0050] Once the angle between the correction instruments 10 is reached, the final tightening of the nuts 6 is carried out to maintain the triangular fixing assemblies in a fixed and rigid position on each of the vertebrae.

[0051] Maneuvering instruments 12, 13 connecting the correction instruments 10 of each of the triangulation assemblies are then placed on the attachment means 11 of the correction instruments 10. The maneuvering instruments comprise a rack system, allowing a progressive separation or rapprochement of the correction instruments 10 between them via the triangulation assemblies, and therefore a progressive compression or distraction of the vertebrae between them. The fixed and rigid position of the fixation assembly obtained using the maneuvering instruments makes it possible to stabilize the vertebrae in any position, and thus to perform a number of surgical procedures on a stable spinal column. In the case of an osteotomy, this fixed and rigid position provides essential stability to the surgical procedure, the partial removal of a vertebral body resulting in significant instability of the spinal column.

[0052] A first operating instrument 12, connecting the correction instruments 10 of each of the rectification assemblies, is thus put in place ( Figure 14a and 14b ). This first instrument allows, in addition to the compression / distraction of the vertebrae 100, 110 carried out subsequently, an angular correction of the vertebrae. The anteroposterior displacement of this maneuvering instrument also allows a direct correction of the anteroposterior positioning of the vertebrae, advantageously in the case of spondylolisthesis. This displacement / correction is possible by the combination of the correction instruments 10, maneuvering instrument positioned in the form of a frame and the attachment means between these instruments of the ball joint type. A handle not shown here could also be positioned at the end of the maneuvering instrument in order to facilitate this displacement. This first instrument also has the advantage of avoiding any instability of the spine when the ball joints are blocked.

[0053] When an osteotomy is necessary, the vertebral bone is cut into a V shape ( Figures 15a and 15b ) with an angle corresponding to the desired lordosis angle in the end and therefore corresponding to the angular spacing of the correction instruments 10 relative to each other (spacing according to the angle α). To do this, the angular positioning of the correction instruments 10 in the predefined position forms a guide for the osteotome-type bone cutting instruments, the V-shaped cuts of the vertebral bone being made parallel to the correction instruments 10.

[0054] In order to ensure the control of compression / distraction correction of the instrumented vertebrae between them, a second maneuvering instrument 13 can be placed between the two correction instruments 10 ( figure 16 ).

[0055] Once the operating instruments are in place, the vertebrae are then corrected. To do this, the correction instruments 10 are moved until they are parallel to each other ( Figures 17a and 17b ), the final parallel positioning of the correction instruments 10 corresponding to the optimal correction of the sagittal angle, the two faces of the V shape created by the osteotomy possibly carried out then also being parallel, or even collinear.

[0056] Once the correction has been carried out, all that remains is to link the triangular fixing assemblies together in order to fix their position before dismantling the correction instruments 10. This connection can be carried out by means, for example, of a longitudinal fixing system 14 composed of hooks 14A and plates 14B ( Figures 18a and 18b ).

[0057] The preceding figures show vertebrae requiring straightening only in the sagittal plane. It is of course obvious that the straightening system according to the invention is not limited to this type of correction, the latter being adapted to allow corrections in all 3 dimensions. Figures 19a to 19c show an example of vertebrae requiring such correction. In order to facilitate understanding of the movement of the vertebrae carried out during their straightening using the straightening system according to the invention, the operating instruments have not been shown.

[0058] Thus, after having positioned the correction instruments 10 of each straightening assembly relative to each other according to the sagittal angle α corresponding to the targeted posterolateral angular correction, a transverse rotation correction is carried out so as to bring the axes 16 of the correction instruments 10 into the same plane, as illustrated in the Figures 20a and 20b . The coronal displacement is then corrected by positioning the handles 17 of the correction instruments 10 parallel to each other, as illustrated in the figures 21 to 21c . The sagittal correction of the vertebrae is then carried out by bringing, as in the previous example of vertebrae straightening, the axes 16 of the correction instruments 10 parallel to each other ( Figure 17a ).

[0059] The movements (transverse rotation, coronal displacement and sagittal displacement) applied to the vertebrae have been described sequentially. It is of course obvious that all of these movements can be performed in a single gesture. The measuring instrument 15 described in the initial phase of angular positioning of the correction instruments can also be used during all the surgical steps described in order to control and measure the progress of the correction.

[0060] THE figures 22 and 23represent an alternative embodiment of a vertebrae straightening assembly 1A. The implementation of the assembly remains similar to that previously described. The straightening assembly of this alternative, however, differs from that previously described in terms of the arrangement of the connectors 500 as well as the anchoring means 200.

[0061] In this variant, the connector 500 is formed of two separate parts 500A, 500B,

[0062] One of the parts 500A forms a sleeve intended to receive the triangulation bar 3. The sleeve is provided at each of its two ends with a notch 501A, 503A. It is provided on its external face with a threaded axis 502A. The notches are arranged opposite each other, on either side of the threaded axis.

[0063] The other part 500B has a groove 501B arranged to receive the upper part 220 of the bone anchoring means. It has a hole 502B for the passage of the threaded shaft 502A. The groove 501B is arranged to be arranged opposite one of the notches 501A. Thus, when the two parts are assembled by screwing the tightening nut 6 onto the threaded shaft 502A which extends through the passage hole 502B, the upper part 220 of the bone anchoring means and the triangulation bar 3 are clamped against each other by pinching, the two parts acting as a vice.

[0064] As understood, the sleeve / threaded rod / upper portion arrangement of the bone anchor means is such that it allows multi-axial movement of the triangulation bar before full tightening of the nut, thereby allowing adjustment of the angular position of the correction instrument mounted on the triangulation bar (instrument not shown).

[0065] The invention is described in the foregoing by way of example. It is understood that those skilled in the art are able to carry out different variant embodiments of the invention without departing from the scope of the invention.

Claims

1. An assembly for rectifying (1, 1A) vertebrae, comprising: - two bone anchoring means (2, 200) intended to be implanted on a same vertebra, - a structure for bridging the bone anchoring means to one another, said bridging structure, which is implantable, comprising a triangulation bar (3) and connection means (4) for connecting the triangulation bar (3) to each bone anchoring means (2, 200), - a correction instrument (10) mounted on the triangulation bar, - means for locking the triangulation bar (3) on the bone anchoring means via the connection means, the triangulation bar thus forming, with the bone anchoring means, a rigid triangular assembly, and - means for adjusting the angular position of the correction instrument (10) relative to the vertebra at a determined angle, the assembly for rectifying (1, 1A) being characterized in that the connection means (4) comprise two connectors (5) each comprising a first passage area defining a longitudinal passage axis for the triangulation bar (3) and a second passage area arranged to receive one of the bone anchoring means, said second passage area having an oblong form oriented parallel to the longitudinal passage axis of the first passage area, the connectors forming the means for adjusting the angular position of the correction instrument (10).

2. The assembly for rectifying (1, 1A) vertebrae according to claim 1, characterized in that the connection means comprise means for adjusting the angular position of the correction instrument (10).

3. The assembly for rectifying (1, 1A) vertebrae according to claim 2, characterized in that the triangulation bar (3) comprises an attachment area (33) for the correction instrument (10), arranged to provide secure attachment, in rotation and in translation, of the correction instrument (10) on the triangulation bar.

4. The assembly for rectifying (1, 1A) vertebrae according to claim 3, characterized in that the triangulation bar (3) comprises a flattened portion forming the attachment area (33).

5. The assembly for rectifying (1, 1A) vertebrae according to claim 3 or 4, characterized in that the attachment area (33) is central.

6. The assembly for rectifying (1) vertebrae according to any one of the preceding claims, characterized in that the first passage area is shaped to enable the sliding and the rotation of the triangulation bar (3) within itself before it is locked on the connectors (5).

7. The assembly for rectifying (1) vertebrae according to any one of the preceding claims, characterized in that each connector (5) is in the form of a clip comprising a part having a C-shaped section extended by two arms comprising respectively an orifice (523, 524), the orifices of each arm being arranged facing one another in order to define the second passage area, while the C-shaped section delimits the first passage area.

8. The assembly for rectifying (1) vertebrae according to claim 7, characterized in that the orifices (523, 524) are arranged to have an axial offset relative to one another.

9. The assembly for rectifying (1, 1A) vertebrae according to any one of the preceding claims, characterized in that each bone anchoring means (2) comprises a fixed screw head (20) extended on either side by a lower threaded part (21) for implantation in the vertebra and an upper threaded part (22) onto which a retaining nut (6), forming the locking means, is intended to be screwed.

10. The assembly for rectifying (1, 1A) vertebrae according to any one of the preceding claims, characterized in that the triangulation bar (3) is straight or curved.

11. A system for spinal osteosynthesis comprising at least two assemblies for rectifying vertebrae according to any one of the preceding claims, said assemblies (1, 1A) being intended to be implanted on two discrete vertebrae and to be connected to one another.

12. The system for spinal osteosynthesis according to claim 11, characterized in that it comprises at least one maneuvering instrument connecting the correction instruments (10) of each of the triangulation assemblies to one another.