WO2010136665A1

WO2010136665A1 - System for connecting two spinous processes

Info

Publication number: WO2010136665A1
Application number: PCT/FR2010/000381
Authority: WO
Inventors: Hassan Razian
Original assignee: Hassan Razian
Priority date: 2009-05-27
Filing date: 2010-05-20
Publication date: 2010-12-02
Also published as: FR2945930A1; FR2945930B1

Abstract

The present invention relates to the systems for connecting two spinous processes (E1, E2) of two vertebrae (V1, V2) of the spine, respectively. The interspinous system of the invention is essentially characterized in that it comprises two staples (11, 12), each including a first U-shaped part that is attachable onto a spinous process (E1, E2) and two lugs (21, 22) connected to the two outer side surfaces (17, 18) of the two side arms (15, 16) of the first part, respectively, and an H-shaped linking base (30) including two portions (31, 32), each consisting of a second U-shaped part, the second parts being arranged so as to match the outside of the two first U-shaped parts, a means (33) for connecting the two second parts, and an opening (34-37) formed in each side arm of the second parts such that, when the two first parts are housed in the two second parts, respectively, the lugs (21, 22) pass through the corresponding openings (34-37).

Description

SYSTEM FOR CONNECTING TWO THIN PROCESSES

The present invention relates to systems for connecting two spinous processes respectively of two vertebrae. We know that, for various reasons, there are disorders in the vertebrae that are very traumatic for those who suffer from it. As such, we can mention the facet syndrome, the recurrence of herniated disc, the degenerative or iatrogenic deficit, a loss of interspinous height, etc. In an attempt to eliminate these disorders in the least traumatic way possible for the patient and to ensure the intervertebral stability, it is possible to use interspinous systems.

These systems are interesting from the operative point of view because they are easy to implement by the posterior route and can even be the object of more frequent interventions, if only to adapt them according to the evolution of disorders.

Many interpinous systems are known, for example those consisting of a plate whose ends are respectively fixed on the spinous processes of two consecutive vertebrae by means of screws or the like.

There are also riders who are straddling the two consecutive spinous processes, and whose ends are secured to the two thorny processes by means of screws traversing perpendicularly these spinous processes or ligaments surrounding them. Such systems defined above are for example described in the

US-A-2007/233096, EP-A-322334, FR-A-2717675, FR-A-2892616 and US-A-2006/085070.

These known interspinous systems generally give very good results but have a major disadvantage, the fact that their implantation is relatively delicate, including the establishment of screws perpendicular to the spinous processes or ligaments. In addition, their implantation involves a relatively long and deep incision in the patient, which induces significant trauma for the patient and a relatively long healing time.

In addition, some of these interpinous systems according to the prior art are not really reliable because they leave a possibility of movements or mini movements between the spinous processes and, in particular, the ligaments for the attachment of the riders. These mini movements generate friction on the bony wall of the spinous processes and this friction can induce a loosening of the implant or a bone resorption, even to the fracture of the spinous processes. Thus, it is an object of the present invention to provide a system for connecting two spinous processes of two vertebrae, respectively, which greatly reduces the aforementioned disadvantages of prior inter-spinous systems.

More specifically, the present invention relates to a system for connecting two spinal processes respectively of two vertebrae of a spine, characterized in that it comprises:

A / two riders, each rider including at least:

(i) a first substantially U-shaped part adapted to be fixed, astride, on a spinous process, and (ii) two lugs integral respectively with the two external lateral faces of the two lateral branches of the first part, these two lugs being substantially perpendicular to these two outer lateral faces and substantially collinear with each other; and

B / a substantially H-shaped connection base, this connection base comprising at least:

(i) two upper and lower parts, each consisting of a second substantially U-shaped part, the two second parts being arranged to be substantially complementary to the outside of the first two parts so that the latter are able to be housed respectively in the two seconds pieces,

(ii) means for connecting the two second pieces, and (iii) an orifice made in each side branch of the second pieces so that when the first two pieces are respectively housed in the second two parts, the lugs pass through the corresponding holes.

Other features and advantages of the present invention will become apparent from the following description given with reference to the accompanying drawings, by way of illustration but in no way limiting, in which:

FIG. 1 is a perspective and exploded view of a schematic representation of an embodiment of the system according to the invention for connecting two spinous processes of two vertebrae respectively. FIGS. 2 and 3 represent two views, respectively in perspective and side, an improvement to one of the components of the system according to the invention for connecting two spinous processes respectively two vertebrae shown in Figure 1,

FIG. 4 is a sectional view of the embodiment of the interspinous system according to the invention illustrated in FIG. 1, but assembled and implanted on two spiny processes, said section being made in a plane substantially perpendicular to the longitudinal axis of Figure 5 is a side view of the interspinous system according to the invention implanted on two spinous processes of two consecutive vertebrae.

With reference to the appended figures, the present invention relates to an interspinous system for connecting two spinal processes E1, E2, respectively of two vertebrae V1, V2 of a spinal column, FIGS. 4 and 5. This interspinous system comprises all first two riders 11,

12, each jumper comprising a first substantially U-shaped piece adapted to be fixed, astride, on a thorny process E1, E2. This first piece will be fixed by any means, for example by screw or the like, but advantageously by crimping for its simplicity of installation, the crimping being able to be obtained simply by bringing the two lateral branches 15, 16 closer to each other. of the first piece.

The interspinous system further comprises two lugs 21, 22 integral respectively with the two outer lateral faces 17, 18 of the two lateral branches 15, 16 of the first part, the external lateral faces being those facing outwards of the interbranch space of the U-shape ^. It is specified that the U-shape of the first pieces given here is indicative. of their general form, but that any form which can be assimilated to it forms an integral part of the invention. These first pieces can be made in plates or sheets full, perforated or screened, and even stand for example in the form of claws or the like. The material in which these first two parts are made is, for example, titanium, the alloy known under the terminology TA6V-ELI, a stainless steel, a chromium-cobalt alloy, etc.

The two lugs 21, 22 relative to each first U-shaped part are substantially perpendicular to the two outer lateral faces 17, 18 defined above and substantially collinear with each other 23, preferably being cylindrical in shape to be able to, as explained above, after, serve as rotational bearings. It is specified that, in the sense of the present description, "cross section" means the dimension of the diameter of a pin when it is cylindrical of revolution, or any dimension comparable to this diameter when the pin does not have a form of revolution.

The system further comprises a connection base 30 substantially H-shaped, this connection base 30 comprising two parts respectively high and low 31, 32, each consisting of a second substantially U-shaped part. The second two parts are arranged to be substantially complementary externally of the first two parts so that the latter are able to be housed respectively in the two second parts. In fact, these second pieces also form jumpers that are substantially homothetic, with a coefficient greater than one, jumpers according to the first pieces defined above.

The base 30 further comprises means 33 for connecting the two second parts. These connecting means 33 may be of different shapes and / or of different types, preferably constituted by one of the the following means: solid fixing means, elastic connection means, rotational connection means, translation linking means, flexural connection means, connecting means comprising a combination of at least two of the following functions: elastic connection, connection in rotation, translation connection, flexural connection.

All these means are known in themselves and will therefore not be more fully described for the sole purpose of simplifying the present description. It will be the same for their achievement which is in the field of the skilled person. The base 30 further comprises an orifice 34-37 made in each lateral branch (four branches) 38, 39 of the two second parts so that, when the first two parts are respectively housed in the two second parts, the lugs 21, 22 pass through the corresponding orifices 34-37. These orifices must be considered essentially as seats for the pins defined above so that the latter can rotate without too much stress including friction.

According to another advantageous characteristic of the invention, it is preferable that the two lugs 21, 22 respectively integral with the two outer lateral faces 17, 18 of the two lateral branches 15, 16 of the first piece, have a length greater than the thickness. parts of the lateral branches 38, 39 of the second parts in which the corresponding orifices 34-37 are respectively made, so as to allow crimping of the jumpers 11, 12 even when they are already arranged between the lateral branches 38, 39 of the second parts without distorting these branches.

The interspinous system according to the invention has an important advantage, the fact that, when the H-base moves, the second parts do not rub directly on the thorny processes since, between these second parts and the thorny processes, are interposed the first pieces, which are fixed in relation to the processes.

According to a preferred embodiment, at least one of the first two parts comprises at least one pin 40 projecting on the inner face one of the two lateral branches 15, 16 of the U, preferably, as illustrated, several pins on each leg, arranged face to face or offset to be able, when the two branches are fixed, preferably by crimping, on a thorny process , anchor in the bone part of this process (Figure 4) and thus perfectly secure the first part of the rider 11, 12, with the thorny process E1, E2, Figures 4 and 5.

However, according to another characteristic of the invention, the system may comprise at least one saber-like blade 41, 42 or the like, as shown in phantom in FIG. 4, projecting into the interbranch space of a first piece, advantageously in a plane substantially parallel to the two lateral branches of the first piece, although this saber-blade can however have any other orientation with respect to the spinous processes.

According to a first embodiment of the system, this saber blade 41, 42 can be protruded on the base of the U which constitutes the bottom of a first part and replace the pins 40 mentioned before. In this case, the pins 40 may be replaced by asperities or the like of a lower height than the pins 40 which have been illustrated.

But, according to a second embodiment of the system as schematically illustrated in dashed lines in Figure 4, the blade can be made to protrude from the bottom of a second U-shaped part belonging to the H connection base 30 In this case, there will be provided a light 43, 44 in the bottom of the first pieces so that, during the implantation of the interspinous system, the saber blade passes through this light, the bottom of the first piece associated with the second piece whose saber blade is secured.

The introduction of the jumpers can then be done in several ways, either by translation of the jumpers perpendicular to the longitudinal axis of the spinous processes, or by rotation of these jumpers in a plane containing the longitudinal axis.

These two first and second embodiments of the system with at least one saber blade 41, 42 may be advantageous when the system must be assembled before implantation by the surgeon, for example by factory. In this case, the implantation of the system will be done by rotation about an axis perpendicular to the longitudinal axes of the spinous processes, by means of an adapted ancillary. After anchoring ^• the two blades respectively in the two spinous processes E1, E2, the two jumpers 11, 12 are set by applying the crimping forces only on the emerging ends of the two lugs 21, 22, so as to avoid that these forces crimping are applied to the lateral branches 38, 39 of the two second pieces.

According to an improvement of the interspinous system described above, for a purpose of good positioning and good fixing of each rider 11, 12 on a thorny process E1, E2, it is advantageous that at least one of the first pieces, if not both, comprises a curved fin 42 secured to one of the two free sides of the base 49 of the U, for example a so-called "laminar" hook, and having a concave curvature facing the two lateral branches 15, 16 of the U, so as to be able to lodge in the hollow formed between the foot of the spinous process E1, E2 of a vertebra V1, V2 and the blade Lav of the vertebra, FIGS. 2 and 3 in combination with FIG. 5 for locating the reference Lav.

According to a preferred embodiment, at least the two orifices 34-35 made in one of the second pieces are of oblong shape, having a width at least equal to the cross section (possibly the diameter) of the two lugs 21, 22 with which they must respectively cooperate and a determined length greater than this same section. These oblong orifices are evoked in broken lines in Figures 1 and 4, and in continuous lines in Figure 5.

These oblong holes allow, when the interspinous system according to the invention is implanted as explained hereinafter, to obtain a relative displacement, within the limit of their length, of the two spiny processes E1, E2 which results in a relative rotation. of these two processes with respect to each other and therefore of the two vertebrae V1, V2, arrow Fr, substantially around a point Pr, FIG. 5, which is located at the level of the intervertebral disc Dv situated between the two vertebrae V1, V2, of to allow the spine to retain at least a partial possibility of flexion, but without applying efforts on the bones.

Preferably, the lateral branches 38, 39 of the second parts are made of a material having a certain resilience, for example in thin plates or titanium analogs, a stainless metal, etc., so that, under the action of given forces, they are able to be arranged as the lateral branches of a V, and to return to their position of side branches of a U when the forces are canceled, so as to be able to place the lugs 21, 22 in the orifices corresponding 34-37 during the implementation of the system between two spiny processes E1, E2.

In general, the system according to the invention may be provided so that at least one of the first two pieces is arranged to be housed in one of the two second pieces in one of the two following positions: i) so that the two U respectively of the first piece and the second piece are oriented in the same direction with respect to each other, that is to say with the two bases facing each other close to each other. one of the other and with the openings defined by the free ends of the lateral branches located on the same side, and (ii) so that the two L ⁾ respectively of the first piece and the second piece are reversed the one with respect to the other, that is to say with the two bases facing away from each other by a distance at least equal to the height of the lateral branches of the first part and with the openings defined by the free ends of opposite lateral branches.

However, it is the position (i) defined above that will be widely preferred, essentially because the implantation of the interspinous system in this configuration will be the least traumatic for the patient, because it requires a smaller incision and less deep than the implementation of the system in the configuration according to solution (ii).

In the embodiment illustrated, in particular in FIG. 4, when the system is assembled in position (i) above, the outer face of the base of the U of the first pieces is positioned at a distance of certain distance from the inner face of the base of the U of the second pieces. In this embodiment, all the forces exerted between the first and second parts are transmitted by the lugs 21, 22. Of course, these lugs are made to be able to transmit all these forces without undergoing deformation, breaks, etc.

However, according to another characteristic of the invention, the system is designed so that, when assembled in the position (i) defined above, the orifices 34-37 and the lugs 21, 22 have between them a certain play so that, in the rest position, the outer faces of the bases 49 of the first U-shaped parts can be in contact with the inner faces of the bases of the second U-shaped parts, so that the transmitted forces are distributed over surfaces much larger than those that may present elements such as lugs 21, 22, and that for the purpose of conferring on the inter-spinous system according to the invention a greater reliability. It is even possible to provide that these contacting faces, respectively outer and inner of the U-shaped parts, are able to pivot on one another to allow easier rotation of the two spiny processes E1, E2, and therefore of both vertebrae V1, V2.

It should also be emphasized that the height of the lateral branches of the first and second parts intended to cooperate with each other will be determined by the Practitioner to be able to possibly place two systems on three consecutive vertebrae, either facing one of the other that is to say, head to tail, or offset, that is to say one next to the other.

Of course, to make it easier to assemble the elements of the system, especially during its implantation, the orifices 34-37 made in the lateral branches 38, 39 of the second parts are located near the free ends of these lateral branches opposite the ends which are connected to the bases of the U, essentially for the purpose of imposing on the two lateral branches 38, 39 of the second parts a minimum elastic deformation.

The system according to the invention as described above is used as follows when it is in its configuration (i) defined above: Firstly, the surgeon makes an incision in the patient's back, at the level of the two thorny processes that he has to connect with the system according to the invention. It is immediately clear that this incision has a length at most equal to the distance separating the two thorny processes. It is therefore very small with respect in particular to that which would be necessary for the implementation of the system in the configuration (ii) defined above and with respect to that which is necessary for the implementation of the systems according to the prior art such that defined in the preamble of this description. Once this incision is made, the surgeon spreads the interspinous ligament on the side, without cutting it, then, using an ancillary forceps, he introduces the two riders 11, 12, places them astride the processes spiny, taking care to arrange them so that their fin 42, if it exists, is placed in the hollow defined above, and crimped the two riders on both thorny processes by penetrating the pins 40 in the bone part of these process.

When the two jumpers are thus implanted, it introduces the connecting base 30, separates its lateral branches 38, 39 to introduce the lugs 21, 22 into the corresponding orifices 34-37, then releases them to trap the two jumpers, the orifices 34-37 respectively surrounding the lugs 21, 22.

The implantation of the interspinous system according to the invention is complete and it remains for the surgeon to replace the interpinous ligament in its place and to suture the incision. When the system is pre-assembled as explained above, for example in the factory, the surgeon grasps the entire system and implants it as described previously by means of a suitable ancillary by introducing it in a horizontal position between the two. spinous process, then by rotating it to put it in vertical final position with the blades 41, 42, when they exist, anchored in the processes. He ends by crimping the two riders.

It is specified that, if the system comprises oblong orifices as described above, the spine will also retain its ability to free bending, at least partially within the length of these oblong holes, the limit positions being obtained when the lugs abut against the ends of the orifices.

As described above, it is apparent that the interspinous system according to the invention has achieved the goals defined in the preamble. In particular, it has a very simple structure and allows easy implantation less traumatic for the patient than the interpinning systems of the prior art.

Claims

1. System for connecting two spinous processes (E1, E2) or two vertebrae (V1, V2) of a spinal column, characterized in that it comprises:

A / two riders (11, 12), each rider comprising at least:

(i) a first substantially U-shaped part capable of being fixed, astride, on a thorny process (E1, E2), and

(ii) two lugs (21, 22) integral respectively with the two outer lateral faces (17, 18) of the two lateral branches (15, 16) of the first piece, these two lugs (21, 22) being substantially perpendicular to these two external lateral faces (17, 18) and substantially collinear with each other (23); and

B / a connection base (30) substantially H-shaped, this connection base (30) comprising at least:

(i) two upper and lower parts (31, 32), each consisting of a second substantially U-shaped part, the two second parts being arranged to be substantially complementary to the outside of the first two parts so that the latter are suitable for to lodge respectively in the two second rooms,

(ii) means (33) for connecting the two second pieces, and (iii) an orifice (34-37) formed in each side branch (38, 39) of the second pieces so that when the first two pieces are respectively housed in the two second parts, the lugs (21, 22) pass through the corresponding orifices (34-37).

2. System according to claim 1, characterized in that each first part is adapted to be fixed by crimping, on horseback, on a thorny process (E1, E2), by bringing one of the two branches closer together. lateral (15, 16).

3. System according to claim 2, characterized in that at least one of the first two parts comprises at least one pin (40) projecting on the inner face of one of the two lateral branches (15, 16) of the U.

4. System according to claim 2, characterized in that it comprises at least one saber blade (41, 42) projecting into the interbranch space of a first piece relative to the base of the U of this first piece .

5. System according to one of claims 1 to 4, characterized in that at least one of the first parts comprises a curved fin (42) integral with one of the two free sides of the base (49) of the U , this fin having a concave curvature facing the two lateral branches (15, 16) of the U, so as to be housed in the hollow formed between the foot of the spinous process of a vertebra and the blade of said vertebra.

6. System according to one of claims 1 to 5, characterized in that at least the two orifices (34-37) made in one of the second pieces are of oblong shape, having a width at least equal to the cross section of the two lugs (21, 22) with which they must respectively cooperate and a predetermined length greater than this same section.

7. System according to one of claims 1 to 6, characterized in that the means (33) for connecting the two second parts are constituted by one of the following means: solid attachment means, elastic connection means, means rotary connection means, translational linking means, flexural connection means, connecting means comprising a combination of at least two of the following functions: elastic connection, rotational connection, translation connection, flexural connection.

8. System according to one of claims 1 to 7, characterized in that at least one of the first two parts is arranged to be housed in one of the two second pieces according to one of the two following positions: the two U respectively of the first piece and the second piece are oriented in the same direction relative to each other, the two U are inverted relative to each other.

9. System according to claim 8, characterized in that the first two parts are arranged to be respectively housed in the second two parts so that the two U of each pair of first and second parts are oriented in the same direction the one compared to the other.

10. System according to claim 9, characterized in that the facing faces of the two bases respectively of the first two and second U-shaped parts are in contact with each other.

11. System according to one of the preceding claims, characterized in that the orifices (34-37) formed in the lateral branches (38, 39) of the second parts are located near the ends of said side branches opposite the ends which are related to the bases of U.

12. System according to one of the preceding claims, characterized in that the two lugs (21, 22) secured respectively to the two outer lateral faces (17, 18) of the two lateral branches (15, 16) of the first piece, have lengths greater than the thickness of the portions of the lateral branches (38, 39) of the second parts in which the respective orifices (34-37) are respectively formed.