SYSTEM FOR CONNECTING AT LEAST TWO VERTEBRAL PROCESSES

Abstract

The present invention relates to a system for connecting two vertebral processes E. The system comprises at least two rings 10, at least one of the rings 10 consisting of a part 20 having a cylindrical axial orifice 22 of revolution opening at at least one end 23 of this part 20, a thread 25 formed on the wall of the orifice 22, another part 40 having a cylindrical notch 41 having a substantially U-shaped cross-section, the end 43 of this part 40 having a base, and means for cooperatively mounting respectively the apex 24 of the part 20 and the base 43 of the part 40, further providing a rod 50 adapted to fit into the notch and means for securing the rod 50 to the part 40. Figure 1

Description

Title of the invention: SYSTEM FOR CONNECTING AT LEAST TWO VERTEBRAL PROCESSES

[0001] The present invention relates to systems for connecting two vertebral processes respectively of two vertebrae.

[0002] It is known that, for various reasons, disorders can occur in the vertebrae, facet joints, and intervertebral discs that are very traumatic for the living beings affected. Examples include facet joint syndrome, recurrent herniated discs, degenerative or iatrogenic deficits, loss of interspinous height, etc.

[0003] To attempt to eliminate these disorders in the least traumatic way possible for the patient and to ensure intervertebral stability, interspinous systems can be used. These systems are advantageous from a surgical point of view because they are easy to implant via a posterior approach and can therefore even be the subject of more frequent interventions, if only to adapt them according to the evolution of the disorders.

[0004] Numerous interspinous systems are known, for example, those consisting of a plate whose ends are respectively fixed to the spinous processes of two consecutive vertebrae by means of screws or the like. There are also saddles that are inserted across two consecutive spinous processes and whose ends are secured to these two spinous processes by means of screws passing perpendicularly through these spinous processes or by ligaments surrounding them.

[0005] There is also a system which has been developed by the Applicant and which has been the subject of Patent FR 2 961 089.

[0006] The system according to this Patent essentially comprises at least two rings, each comprising a through bore of generally substantially cylindrical shape of revolution defined along a longitudinal axis, so that they are suitable for being inserted respectively around the two spinous processes, and means for linking the two rings according to at least one degree of freedom.

[0007] The system as defined in this Patent is perfectly suited for spinous processes which have relatively large dimensions, such as those which are very prominent at the back of the vertebrae, but less suited for processes which are laterally to the transverse plane of the vertebrae, which are of smaller dimensions.

[0008] Also, the present invention aims to provide a system for connecting, but not exclusively, protuberances and / or processes of the spinous or similar type which are of small dimensions both transversely and vertically.

[0009] More specifically, the present invention relates to a system for connecting two vertebral processes, comprising at least two rings, each having a generally cylindrical bore defined along a longitudinal axis so that the two said rings are able to be inserted respectively around the two processes, and means for connecting the two said rings together, the system being characterized by the fact that at least one of the two rings is made up of a first piece having a substantially cylindrical external shape having a cylindrical axial orifice of revolution opening at at least a first end of this first piece, the second end of this first piece opposite the opening of said orifice constituting the apex of this first piece, a first thread being made in the wall of said orifice;of a second piece also having a substantially cylindrical external shape, this second piece comprising a cylindrical notch having a substantially U-shaped cross-section opening at one end of said second piece, the other end of this second piece opposite the opening of said notch constituting the base of this second piece, this second piece having substantially the same external shape as said first piece; and of means for mounting in cooperation respectively the top of the first piece and the base of the second piece, and that the means for linking the two said rings comprise a rod with a cross-section at most equal to the width of said U-shaped notch, so that this rod is able to fit into this notch, and of means for securing said rod, when it is in said notch, with said second piece.

[0010] Other features and advantages of the present invention will become apparent from the following description given with reference to the accompanying drawings, which are by way of illustration but in no way limiting, in which:

[0011] Figure [1] represents, in schematic form, an embodiment of the system according to the present invention,

[0012] Figure 2 represents, in schematic form, another embodiment of the system according to the present invention, and

[0013] Fig. 3 is a view of an example of the system according to the invention suitable for implementation in situ in the human body.

[0014] It is specified that, when, according to the definition of the invention, the object of the invention comprises “at least one” element having a given function, the described embodiment may comprise several of these elements. Conversely, if the embodiment of the object according to the invention as illustrated comprises several elements of identical function and if, in the description, it is not specified that the object according to this invention must necessarily include a particular number of these elements, the object of the invention may be defined as including “at least one” of these elements.

[0015] It is specified that when, in the present description, an expression defines by itself, without any particular specific mention concerning it, a set of structural characteristics, these characteristics may be taken, for the definition of the object of the protection sought, when this is technically possible, either separately, or in total and / or partial combination.

[0016] It is further specified that, in the present description, if the adverb "sensiblement" is associated with a qualifier of a given means, this qualifier must be understood in the strict or approximate sense.

[0017] It should also be noted that, across all the figures, the same references designate the same means having the same function, regardless of their graphical representation.

[0018] It is further emphasized that, for the purposes of the present invention, the term vertebral process should be understood as defining any protruding bony protuberance present on the vertebrae.

[0019] The present invention relates to a system for connecting two vertebral processes E of two vertebrae, but it is clearly stated that this invention can be applied to connecting more than two vertebrae.

[0020] With reference to [Fig. 1], which schematically illustrates a preferred embodiment of the system according to the invention, this system comprises at least two rings 10 (only one being shown in the figures) each comprising a generally substantially cylindrical bore 11 defined along a longitudinal axis, so that the two rings are able to be inserted respectively around the two processes E, and means for securely linking the two rings together.

[0021] The system according to the invention is essentially characterized in that at least one of the two rings 10 comprises a first part 20 having a substantially cylindrical external shape. This first part comprises the opening 11 which is constituted by a cylindrical axial orifice 22 of revolution opening at at least a first end 23 of this first part, the second end 24 of this first part being opposite the opening of the orifice constituting the apex of this first part, a first thread 25 being formed in the wall of the axial orifice 22.

[0022] The ring comprises a second piece 40, also having a substantially cylindrical external shape, this second piece comprising a cylindrical notch 41 having a substantially U-shaped cross-section of a given width, opening at a first end 42 of the second piece 40, the second end 43 of this second piece opposite the opening of the notch forming the base of this second piece, this second piece having substantially, but not exclusively but preferably, the same external shape as the first piece. As an example of a preferred embodiment, the first and second pieces 20, 40 are cylindrical in shape of revolution with substantially the same diameter.

[0023] The ring also includes means for cooperatively mounting the top 24 of the first part 20 and the base 43 of the second part 40.

[0024] Fig. 1 illustrates one embodiment of the means for cooperatively mounting the top 24 of the first part and the base 43 of the second part.

[0025] In this embodiment, these means consist of the fact that the first and second parts are made in one piece from the same bar, for example from a given material such as stainless steel or titanium.

[0026] Figure 2 illustrates another embodiment of these means for cooperatively mounting the apex 24 and the base 43 of the first and second parts, respectively. In this other embodiment, these means consist of a stud 60 mounted projecting from the apex 24 of the first part 20, a bore 61 formed transversely in the base 43 of the second part 40, this bore having a cross-section substantially complementary to that of the stud so that the latter is able to be inserted into it, and means 62 for fixing the stud in the bore. These means can be of any type, for example, a nut screwed onto the free part of the stud emerging from the bore 61.

[0027] Yet another embodiment (not illustrated) of these means for mounting in cooperation the apex 24 and the base 43 respectively of the first part and the second part can be provided: for example a ball joint with two elements mounted in cooperation according to at least one degree of rotation, for example a cylindrical rotation or a spherical rotation, with respectively the apex 24 of the first part 20 and the base 43 of the second part 40.

[0028] Advantageously, depending on the type of ball joint, means may be provided to lock the two elements of the ball joint together in a desired position when the relative position of the two parts 20, 40 has been determined by the Practitioner, for example with a pin, a clamping screw or the like.

[0029] The system according to the invention further comprises means for linking together at least two rings of the system.

[0030] These means for connecting two rings comprise a rod 50 with a cross-section at most equal to the width of the U-shaped notch 41, so that this rod is able to fit into this notch, and means for securing the rod 50, when it is in the notch 41, with the second piece 40.

[0031] According to an advantageous embodiment, when the wall of the notch 41 has a cylindrical surface of revolution, the means for securing the rod 50, when it is in the notch 41, with the second part 40 are constituted by a locking screw 53 suitable for being screwed into a thread 55 made on the wall of the notch 41, so that the locking screw is suitable, by screwing, for firmly pressing the rod 50 against the bottom of the notch 41.

[0032] Preferably the first thread 25 defined above is a bone thread to anchor well in the bony part of a process E.

[0033] According to a possible and advantageous embodiment, as illustrated in [Fig.1], to secure its attachment to the process E, the ring 10 further comprises a penetrating screw 70 suitable for linking at least one of the first and second parts 20, 40 with the bony part of the process E.

[0034] More specifically, according to a possible embodiment illustrated in [Fig.1], the penetrating screw 70 is positioned in a through bore between the bottom of the notch 41 and the axial orifice 22 so as to be able to open into this axial orifice over a non-zero length so as to be able to penetrate into the process E.

[0035] Advantageously, the system includes a second thread 75, this second thread being a bone thread made in the outer side wall of the first part 20.

[0036] This embodiment is an advantageous feature because it allows at least a part of the end 23 of the first piece 20 to penetrate into the bony portion Poe of the vertebra which surrounds the process E.

[0037] The object of the present invention is advantageous from a structural point of view due to its simplicity of construction, and also from that of the ease of implantation by Practitioners which is understood with the description made above, of the possible explanations which are given in Patent FR 2 961 089 mentioned in the preamble of this description and in reference to [Fig.3], noting that, in the embodiment illustrated in this figure, the locking screw 53 is not present.

Claims

Demands

1. A system for connecting two vertebral processes (E), comprising at least two rings (10), each having a generally cylindrical opening (11) defined along a longitudinal axis, such that the two rings are suitable for being inserted respectively around the two processes (E), and means for connecting the two rings together, the system being characterized in that: • at least one of the two rings (10) is made up of: - a first piece (20) having a generally cylindrical external shape comprising a cylindrical axial orifice (22) of revolution opening at at least one first end (23) of this first piece, the second end (24) of this first piece opposite the opening of said orifice constituting the apex of this first piece, - a second piece (40) also having a generally cylindrical external shape,this second part comprising a cylindrical notch (41) having a substantially U-shaped cross-section opening at a first end (42) of said second part, the second end (43) of this second part opposite the opening of said notch constituting the base of this second part, this second part having substantially the same external shape as said first part, and - means for mounting cooperatively respectively the apex (24) of the first part (20) and the base (43) of the second part (40), and that • the means for linking the two said rings comprise: - a rod (50) with a cross-section at most equal to the width of said U-shaped notch (41), so that this rod is able to fit into this notch, and - means for securing said rod (50), when it is in said notch (41), with said second part (40).

2. System according to claim 1, characterized in that the first and second parts (20, 40) are cylindrical in shape of revolution of substantially the same diameter.

3. A system according to claim 2, characterized in that the means for cooperatively mounting the top of the first piece and the basis of the second piece are constituted by the fact that the said first and second pieces are made in one piece from the same bar.

4. System according to any one of claims 1 and 2, characterized in that the means for cooperatively mounting the top of the first piece and the base of the second piece consist of a stud (60) mounted projecting on the top (24) of the first piece (20), a bore (61) made transversely in the base (43) of said second piece (40), said bore having a cross-section substantially complementary to that of said stud so that the latter is able to be inserted into said bore, and means (62) for fixing said stud in said bore.

5. System according to any one of claims 1 and 2, characterized in that the means for cooperatively mounting the top of the first piece and the base of the second piece are constituted by a ball joint with two elements mounted, in cooperation according to at least one degree of rotation with respectively the top (24) of the first piece (20) and the base (43) of the second piece (40).

6. System according to any one of the preceding claims, characterized in that, when the wall of said notch (41) has a cylindrical surface of revolution, the means for securing said rod (50), when it is in said notch (41), with said second piece (40) are constituted by a locking screw (53) adapted to be screwed into a thread (55) made on the wall of said notch (41), so that said locking screw is adapted, by screwing, to press said rod (50) against the bottom of said notch (41).

7. System according to any one of the preceding claims, characterized in that said first thread (25) is a bone thread.

8. System according to any one of the preceding claims, characterized in that at least one ring (10) further comprises a penetrating screw (70) capable of linking at least one of the first and second parts (20, 40) with the bony part of the process (E).

9. System according to claims 3 and 8, characterized in that said penetrating screw (70) is positioned in a through bore between the bottom of said notch (41) and said axial orifice (22) to be able to open into said axial orifice over a non-zero length.

10. System according to any one of the preceding claims, characterized in that it comprises a first thread (25) made in the wall of said orifice (22).

11. System according to any one of the preceding claims, characterized in that it comprises a second bone thread (75) made in the outer side wall of the first part (20).

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