FR3027207A1 - MATERIAL OF VERTEBRAL OSTEOSYNTHESIS - Google Patents

Abstract

This material (1) comprises at least one connecting bar (3) having a mounting portion (11), at least two anchoring members (2) and at least one connecting piece (4, 5) of the assembly type lateral, that is to say comprising an engagement duct of said mounting portion which is laterally offset relative to a mounting duct for mounting the connection piece on the proximal pin that includes the body of associated anchorage. According to the invention, the connecting bar (3) has an eyelet (10) at one end and an intermediate portion (12) connecting said eyelet (10) to said mounting portion (11), said intermediate portion (12) being dimensioned to laterally offset the axis (A) of the eyelet (10) relative to the longitudinal direction (DL) of said mounting portion (11), by a distance (D) substantially equal to the distance by which, on said connecting piece (4), the engagement duct of the mounting portion (11) is offset relative to a mounting duct on a proximal pin 7 of the anchoring member 2.

Description

The present invention relates to a vertebral osteosynthesis material. To treat the degeneration of one or more vertebral joints, it is well known to use vertebral osteosynthesis equipment comprising vertebral anchoring members (pedicle screws and / or laminar hooks), connecting bars, connecting these bars to these anchoring members, and the clamping nuts of these connecting pieces with respect to these bars and these anchoring members. By way of example, patent application publication No. WO 98/55038 describes such a material. Existing materials, in general, do not always appear well suited to the treatment of a short segment of the spine, that is to say, remedying a degeneration at one or two vertebral joints. In particular, they are relatively complicated and slow to implement, which significantly increases the duration of the intervention. Such material may comprise at least one connection piece of the lateral assembly type, such as those described in the aforementioned patent application publication No. WO 98/55038, that is to say in which the engagement conduit the connecting bar is laterally offset relative to a conduit for mounting the workpiece on a proximal pin that includes the associated anchoring member. A material of this type has the disadvantage of not excluding a pivoting of the connecting bar relative to the anchoring members at the time of tightening nuts, occurring especially as this bar is short and curved. This can result in defective angular positioning of the bar, leading to imperfect or even defective correction of the treated segment, and thus involving loosening of the nuts and a repositioning of the bar. In addition, this type of material exists, particularly when the link bar is short, the risk of an exhaust of one or more connecting pieces outside this bar. A vertebral osteosynthesis material may also comprise at least one connection piece of the assembly type on the top, or "tulip", that is to say forming a conduit of engagement of the connecting bar of which axis is intersecting the axis of the vertebral anchoring screw, said duct being closed, after establishment of the connecting bar in it, by a threaded cap screwed into the "tulip". This type of material has the disadvantage of making possible a pivoting of the connecting bar as mentioned above, occurring especially as this bar is short and curved. Threaded plugs can be difficult to set up, especially since the tie rod may not always be fully engaged in the ducts formed by the "tulips", and it is then necessary to use an instrument to push the bar in these conduits so that the installation of the plugs is made possible. In addition, such plugs have reduced dimensions and may suffer a deterioration of their net when they are put in place, a problem known as "cross threading". The present invention aims to provide a vertebral osteosynthesis material overcoming all of these disadvantages. Its main objective is therefore to provide a simple and fast material to set up, and particularly well suited to the treatment of a short segment of vertebral column. Another object of the invention is to provide a material in which the risk of escaping a connection piece of the side assembly type out of the connecting bar is eliminated. A further object of the invention is to provide a material in which the risk of pivoting of the connecting bar with respect to the connecting pieces is eliminated. Yet another object of the invention is to provide a material in which the assembly of the connecting bar to the anchoring members is performed simply and quickly. This material comprises, in a manner known per se, at least one connecting bar having a mounting portion intended to extend along the vertebrae to be treated, at least two anchoring members intended to be anchored in the vertebrae. treating, each anchor member comprising a threaded proximal pin; At least one connection piece of the lateral assembly type, that is to say comprising an engagement duct of said mounting portion which is offset laterally with respect to a mounting duct allowing the mounting of the piece of connection to the proximal pin that includes the associated anchor member; and - clamping nuts for being screwed onto said threaded proximal pins 30 of the anchors. According to the invention, the connecting bar has an eyelet at one end and an intermediate portion connecting this eyelet to said mounting portion, this intermediate portion being sized to laterally offset the axis of the eyelet with respect to the longitudinal direction of said mounting portion, at a distance substantially equal to the distance in which, on said connecting piece, said engagement duct of the mounting portion is offset relative to said mounting duct. During the placement of the material, the loop is engaged directly on the proximal pin of the anchoring member associated with it and said connecting piece, engaged on said mounting portion, is engaged on the proximal pin. of the anchoring member associated with it. The eyelet allows, compared to conventional equipment, to eliminate the need for an additional connecting piece, which would be located near one end of the bar and would therefore be likely to escape out of the bar during the installation of the equipment; said intermediate portion makes it possible, notwithstanding this mounting by means of this eyelet, said mounting portion is positioned with its longitudinal direction substantially parallel to the longitudinal direction of the spine, in order to achieve the immobilization of the vertebrae, or the correction of the position of these vertebrae, adapted way. Said intermediate portion could be at right angles to said mounting portion; however, it is advantageously bent so as to be compact with respect to the surrounding anatomical structures. According to another aspect of the invention, said mounting portion comprises a protruding lug located on the side of the end of this portion opposite to said intermediate portion, and said connecting piece has a longitudinal groove opening into said duct. engagement of the mounting portion, dimensioned to receive said lug in a controlled manner but with sliding ability of the lug in it, said connecting piece being adapted to be engaged on said mounting portion to exceed this lug. Once this overflow has been effected, the connection piece can pivot with respect to said mounting portion; it can then be removed from this mounting portion in the angular position for engagement with the lug. This connecting piece is thus made "captive" with respect to the connecting bar, making the risk of escape of this connection piece with respect to said mounting portion is made very low. Of course, said lug and said groove are advantageously positioned relative to the connecting bar and to the connecting piece so that the angular position of engagement of the connecting piece on the lug is angularly distant from the angular position. that the connecting piece adopts when it is engaged on the proximal pin of the associated anchoring member.

Preferably, said connecting piece has a U-shape, that is to say it comprises a base part and two parallel branches connected to this base part, which are separated from one another by a gap , said engagement duct of the mounting portion being delimited by this base portion and the base of these parallel branches; and said longitudinal groove is formed by the portion of said interstice extending along the base of the parallel branches. With this type of connecting piece, it is thus not necessary to arrange a groove suitable for allowing engagement of the connection piece on the lug: this is the portion of said interstice bordering the engagement duct. of the connecting bar that forms this groove. Preferably, said connecting bar comprises, at the zone of connection of said intermediate portion to said mounting portion, or near this area, a bearing surface for an instrument for moving said piece of connection, engaged on said mounting portion. This instrument thus makes it possible to move one anchoring member relative to the other so as to effect a correction of the position of two treated vertebrae, in which these anchoring members are implanted. Said bearing surface is advantageously in the form of a flange integral with the connecting bar. Such a collar providing a possibility of taking support all around. Said mounting portion may be dimensioned in length so as to receive two sets anchor member / connecting piece; the material 25 then comprises not only a first assembly formed of said connecting piece and said anchoring member associated with this connecting piece, but also a second assembly formed by a second connecting piece and a second anchoring member associated with this second connection piece. According to one possibility, in this case, said second connection piece is of the "open" type, that is to say forms a curved portion which delimits said engagement duct of said mounting portion, said curved portion being able to surround only partially this mounting portion, and - said second set comprises a closing means for closing the engagement duct when said second connecting piece is clamped on said second associated anchoring member. This closure means may consist of a bearing on the anchoring member 5, as described for example by the publication of patent application No. WO 94/15554, or by a bearing on the clamping nut, as described, for example, in Patent Application Publication No. EP 0 441 084. This closing means may also be in the form of a locking piece forming a passage therethrough, this passage permitting the engagement this locking piece on a threaded proximal pin which comprises said second associated anchoring member; said second connecting piece then comprises: a body forming said curved portion, and said locking piece, which comprises: a locking portion intended to bear against said associated second anchoring member and forming a lateral extension closing said engagement duct, and - an assembly portion sized to be engaged in a mounting duct that comprises said body and to slide in this duct, said sliding being between a position of separation of said body and of said second connecting piece, wherein said lateral extension does not prevent the transverse engagement of said mounting portion in said engagement conduit, and a position of approaching said body and the locking piece, wherein said extension lateral is at a distance 25 from said bent portion as it closes said engagement conduit and holds said por mounting in this conduit. The invention will be better understood, and other features and advantages thereof will become apparent, with reference to the appended schematic drawing, showing, by way of non-limiting example, a preferred embodiment of the material it relates. Fig. 1 is a view of this material in perspective; Figure 2 is a perspective view at another angle and slightly enlarged scale; Figure 3 is a side view of a connecting bar that includes the hardware; Figure 4 is a perspective view of this connecting bar and a connecting piece which the equipment also includes; Figure 5 is a partial view of the connecting bar, similar to Figure 4, in a different position of the connecting piece relative to the connecting bar; Figure 6 is a perspective view of a second connecting piece that includes the material; Figure 7 is a perspective view of the second connection piece, at another angle and exploded; Figure 8 is a side view of the second connecting piece, mounted on a partially visible anchoring member, in a possible mounting position of the second connecting piece on the anchor member; and Figure 9 is a view similar to Figure 8, in another possible position of mounting of the second connecting piece on the anchoring member. Figures 1 and 2 show a vertebral osteosynthesis material 1 comprising three anchoring members 2, a connecting bar 3, two connecting pieces 4, 5 and clamping nuts 6.

The anchoring members 2 are of the well known type called "polyaxial", in particular described in the patent application publication No. WO 98/55038. Each of them therefore comprises a screw body 7, a proximal wall 8 (see FIGS. 8 and 9) forming a bearing surface for a connecting piece 4 or 5 or for the lice 10 described below, and a proximal pin articulated 9, part of which is threaded and is adapted to receive a nut 6. The connecting bar 3 is more particularly visible in Figures 3 and 4. It comprises an eyelet 10 at one end, a portion 11 called "correction" , a bent portion 12 intermediate the eye 10 and the mounting portion 11, a lug 13 and a flange 14.

Liceillet 10 is intended to be engaged on the pin 9 of an anchoring member 2, as visible in Figures 1 and 2, until it rests against said proximal bearing wall 8 thereof, and has a countersink 10a on its upper side, adapted to receive a nut 6. The mounting portion 11 is slightly bent as visible in Figures 3 and 4 and is intended to receive the connecting parts 4 and 5. These parts are of the type with lateral assembly, that is to say that they each comprise, as it appears in FIGS. 4 to 7, a conduit 15 for engaging the mounting portion 11 which is offset laterally with respect to a conduit of assembly 16 for mounting the connection piece 4, 5 on the proximal pin 9 that includes the associated anchoring member 2.

As is particularly shown in FIG. 2, the intermediate portion 12 is bent in such a manner as to laterally offset the axis A of the eyelet 10 with respect to the general longitudinal direction DL of the mounting portion 11, at a distance D substantially equal to the distance according to which, on the connecting pieces 4, 5, the axis of the engagement duct 15 is offset relative to the axis of the mounting duct 16. In this way, when the material 1 is assembled as shown on 2, the three anchoring members 2 are substantially aligned parallel to said longitudinal direction DL and after implantation, the connecting bar 3 is disposed substantially parallel to the axis of the treated vertebral segment.

The lug 13 is located at the end of the mounting portion 11 opposite the intermediate portion 12 and protrudes radially from the wall of this portion 11. It has a width (that is to say, its dimension in the direction DL) which is weak, so that the connecting piece 4 can be engaged on the portion 11 beyond it, and has a thickness (that is to say, its dimension perpendicular to the direction DL) which is such that it is able to be slidably engaged in a gap 22 formed by the connecting piece 4, as described below. The flange 14 is located at the region of connection of the intermediate portion 12 to the mounting portion 11. It forms a bearing surface for an instrument (not shown) for moving the connecting piece 4 engaged on the portion 11 relative to the eyelet 10. This instrument, known in principle, comprises a branch adapted to bear against the connection piece 4 and another branch, movable relative to the first branch, adapted to bear against the eyelet 10. As seen particularly in Figures 4 and 5, the connecting piece 4 has a U-shape, that is to say comprises a base portion 20 and two parallel branches 21 connected to this base portion , which are separated from one another by a gap 22. The duct 15 for engaging the portion 11 is delimited by this base portion 20 and the base of these parallel branches 21. As can be understood by reference in FIGS. 5, the piece 4 is adapted to be engaged on the portion 11 by engagement of the gap 22 on the pin 13, which requires that this piece 4 is arranged as shown in Figure 4. The piece 4 is engaged on the portion 11 to exceed the lug 13, which allows it to pivot relative to the portion 11; it then takes, by gravity, the position shown in Figure 5, in which it is "captive" with respect to the connecting bar 3. From this position, it can be brought into its engagement position on the counter 9 of the anchoring member 2 associated by simple pivoting around the portion 11. The connecting piece 5, more particularly visible in Figures 6 to 9, is formed by a body 25 and a locking member 26. It is of the "open" type, that is to say that its body 25 forms a curved portion 27 delimiting said engagement conduit 15, this curved portion 27 being able to surround only partially the mounting portion 11 engaged in this conduit . Outside this portion 27, the body 25 delimits the mounting duct 16. The locking piece 26 comprises a locking portion 28 and an assembly portion 29. The locking portion 28 is intended to bear against the wall proximal 8 of the associated anchoring member 2 and forms a lateral extension 30 of closure of the engagement conduit 15. The assembly portion 29 is in the form of a ring of slightly flexible teeth radially, which is dimensioned for These teeth are able to slide with friction in this duct 16, between a position of separation of the body 25 and the locking piece 26, in which said lateral extension 30 does not not obstacle to the transverse engagement of the mounting portion 11 in the engagement conduit 15, and a position of approaching the body 25 and the locking member 26, wherein said extension l Attral 30 is at a distance from said curved portion 27 as it closes the engagement conduit 15 and holds the mounting portion 11 in this conduit. Figures 8 and 9 show that the part 5 can be placed on the anchoring member 2 with the opening of the duct 15 turned towards the screw body 7 (see Figure 8) or with this opening turned to the opposite side to this screw body 7 (see Figure 9).

In practice, during the placement of the material 1, the eyelet 10 is engaged directly on the proximal pin 9 of the anchoring member 2 associated with it until it bears against the wall 8 of this organ; simultaneously, the connecting piece 4, placed captively on the portion 11, is engaged on the proximal pin 9 of the anchoring member 2 associated therewith. The eyelet 10 makes it possible, compared to conventional equipment, to eliminate the need for an additional connecting piece, which would be located near one end of the bar and would therefore be likely to escape out of the bar. during the installation of the equipment; said intermediate portion 12 allows that, notwithstanding this assembly by means of this eyelet 10, the mounting portion 11 is positioned with its longitudinal direction DL substantially parallel to the longitudinal direction of the spine, so as to immobilize the vertebrae, or the correction of the position of these vertebrae, in a suitable way. Part 5 is used when the third anchor member 2 is made necessary by the treatment to be operated. It is easy to engage laterally on the portion 11 because it is of "open" type, and the locking piece 26 ensures perfect locking of this portion 11 in the conduit 15 which it defines. The invention thus provides a vertebral osteosynthesis material 1 having the decisive advantages of being simple and quick to put in place, and of being particularly well adapted to the treatment of a short segment of the spine, of eliminating the risk exhaust connection piece 4 out of the connecting bar 3, eliminate the risk of pivoting of the connecting bar 3 relative to the connecting pieces 4 and 5, and to allow the assembly of the link bar 3 to the anchoring members 2 in a simple and fast manner.

Claims (10)

REVENDICATIONS1. A vertebral osteosynthesis material (1), comprising: - at least one connecting bar (3) having a mounting portion (11) for extending along the vertebrae to be treated, - at least two anchoring members ( 2) intended to be anchored in the vertebrae to be treated, each anchoring member (2) comprising a threaded proximal pin (9); at least one connection piece (4, 5) of the lateral assembly type, that is to say comprising a conduit (15) for engaging said mounting portion (11) which is offset laterally with respect to a mounting duct (16) for mounting the connecting piece (4) on the proximal pin (9) that includes the associated anchoring member (2); and - clamping nuts (6) intended to be screwed onto said threaded proximal pins (9) of the anchoring members (2); characterized in that the connecting bar (3) has an eyelet (10) at one end and an intermediate portion (12) connecting said eyelet (10) to said mounting portion (11), said intermediate portion (12) being dimensioned for laterally displacing the axis (A) of the eyelet (10) with respect to the longitudinal direction (DL) of said mounting portion (11), at a distance (D) substantially equal to the distance by which, on said connecting piece (4), said duct (15) for engaging the mounting portion (11) is offset relative to said mounting duct (16). 2. Material (1) according to claim 1, characterized in that said intermediate portion (12) is bent. 3. Material (1) according to claim 1 or claim 2, characterized in that: - said mounting portion (11) comprises a lug (13) projecting on the side of the end of this portion opposite said portion intermediate (12), and - said connecting piece (4) has a longitudinal groove (22) opening into said duct (15) for engaging the mounting portion (11), dimensioned to receive said lug (13) so as to adjusted but with sliding capacity of this lug (13) in it, said connecting piece (4) being adapted to be engaged on said mounting portion (11) to exceed this lug (13). 4. Material (1) according to claim 3, characterized in that said lug (13) and said groove (22) are positioned relative to the connecting bar (3) and the connection part (4) so that the angular position of engagement of the connection piece (4) on the pin (13) is angularly distant from the angular position adopted by the connecting piece (4) when it is engaged on the proximal pin (9) the anchoring member (2) associated. 5. Material (1) according to claim 3 or claim 4, characterized in that "- said connecting piece (4) has a U-shape, that is to say comprises a base portion (20) and two parallel branches (21) connected to this base portion (20), which are separated from each other by a gap (22), said conduit (15) for engaging the mounting portion (11) being defined by this base portion (20) and the base of these parallel branches (21); and said longitudinal groove is formed by the portion of said gap (22) extending along the base of the parallel branches (21). 6. Material (1) according to one of claims 1 to 4, characterized in that said connecting bar (3) comprises, at the region of connection of said intermediate portion (12) to said mounting portion (11). ), or near this area, a bearing surface (14) for an instrument for moving said connecting piece (4), engaged on said mounting portion (11). 7. Material (1) according to claim 6, characterized in that said bearing surface 20 is in the form of a flange (14) integral with the connecting bar (3). 8. Material (1) according to one of claims 1 to 7, characterized in that said mounting portion (11) is dimensioned in length to receive two sets of anchor member (2) / connecting piece (4). , 5); the material 25 then comprises not only a first assembly formed of said connecting piece (4) and said anchoring member (2) associated with this connecting piece (4), but also a second assembly formed by a second connecting piece (5) and a second anchoring member (2) associated with this second connection piece (5). 30 9. Material (1) according to claim 7, characterized in that: - said second connecting piece (5) is of the "open" type, that is to say forms a curved portion (27) which defines said duct (15) of engagement of said mounting portion (11), this curved portion (27) being able to only partially surround this mounting portion (11), and - said second set comprises a closing means (26) for closing this engagement duct (15) when said second connecting piece 5 (5) is clamped on said second anchoring member (2) associated. 10. Material (1) according to claim 9, characterized in that said closure means is in the form of a locking piece (26) forming a passage through it, this passage allowing the engagement of this piece locking device (26) on a proximal pin (9) threaded that includes said second anchor member (2) 10 associated; this locking piece (26) comprises: - a body (25) forming said bent portion (27), and - said locking piece (26), which comprises: - a locking portion (28) intended to bear against said second anchor member (2) associated and forming a lateral extension (30) for closing said engagement conduit (15), and - an assembly portion (29) dimensioned to be engaged in a mounting conduit ( 16) which comprises and slidable in said channel (25), said sliding being between a spacing position of said body (25) and said locking piece (26), wherein said lateral extension (30) does not interfere with the transversal engagement of said mounting portion (11) in said engagement conduit, and a position of approaching said body (25) and the locking piece (26), wherein said lateral extension ( 30) is at a distance from said bent portion (27) as it closes said engagement conduit (15) and holds said mounting portion (11) in this conduit.