Connecting device for spinal implant

Abstract

The invention relates to a connecting device (10) for connecting end regions of an implanted first spinal implant, to which a plurality of pedicle screws (70) are each connected at their cranial side by means of a coupling device (80) to a first connecting rod (60), which is connected to an implanted or non-implanted spinal implant part, which has pedicle screws and extends the first spinal implant, having a first fastening device (1) for fastening the connecting device to the first connecting rod (60) and a coupling element for an extended spinal implant part, in particular in the form of a second rod of a pedicle screw to be coupled to the extended spinal implant part, or in the form of a second fastening device (2) for fastening the connecting device to such a second rod (40), further having a rigid bridging element in an intermediate region between the first fastening device of the connecting device and the coupling element, which laterally abuts on the coupling device of the implanted first spinal implant closest to the pedicle screw on the connecting side.

Description

Technical Field

[0001] The present invention relates to a connecting device for connecting the end regions of an already implanted first spinal support, wherein a plurality of pedicle screws are each connected to a first connecting rod at their cranial side by means of a coupling device, the connecting device comprising an implanted or non-implanted spinal support part having pedicle screws and extending the first spinal support, the connecting device comprising a first fastening device for fastening the connecting device to the first connecting rod and a coupling member for the extended spinal support part, the coupling member being in particular in the form of a second rod of a pedicle screw to be coupled to the extended spinal support part or in the form of a second fastening device for fastening the connecting device to such a second rod. Background Art

[0002] Such connecting devices are known and are preferably used when an already existing spinal support is no longer sufficient to support its load but should be extended in order to extend over additional vertebrae. A complete replacement of the existing spinal support would be a greater surgical burden, since the existing connecting rod would have to be exposed over its entire length and released from its clamping position in order to be replaced by a longer rod, and this would be accompanied by significant rehabilitation expenses, especially in the case of frequently used spinal supports, where the fixation of the loosened connecting rod would also eliminate the coupling state of the pedicle screws and the coupling device, which in certain cases are coupled in a specific rotational position.

[0003] Therefore, considering the extension of a previously implanted system. A system known for this purpose for longitudinally connecting two connecting rods is disclosed in US 2008 / 234743A1; however, it has only limited applicability for the above purpose, since it presents threads at the coupling side ends of the two rods, and generally, for already implanted rods, threads are not usually required. The teaching proposed in WO2010 / 120989A1 does not have this idea. In a first variant of the teaching of this document, the existing connecting rod between two adjacent pedicle screws on the connecting side is cut, and (only) the outermost pedicle screws are removed. Then pedicle screws are screwed into this vertebra, the coupling device of the pedicle screws having a laterally extending part with a channel into which the connecting rod of the already implanted spinal support is inserted and fastened with a screw. According to the teaching of WO 2010 / 120989A1, if the already implanted connecting rod is not cut in this way, the extended support as shown in FIG. 14A of this document can be connected as reproduced in the present application Figure 6 in which the bypass rod 247 is placed parallel to the already existing connecting rod and is connected to the already implanted connecting rod and the connecting rod of the extension via a connecting sleeve. Summary of the Invention

[0004] All these systems have their advantages and disadvantages. The object of the present invention is to develop a connecting device of the type described at the beginning, which is improved in terms of a good combination of simple structure, simple installation / use and low load on the bearing device.

[0005] The object of the present invention is achieved by a connecting device of the type described at the beginning, which is essentially characterized in that there is a rigid bridging member in the intermediate region between the first fastening means and the coupling member of the connecting device, in particular in the intermediate region between its first fastening means and second fastening means or between its first fastening means and second rod, said bridging member laterally abutting on the coupling means of the closest pedicle screw of the first implanted spinal support on the connection side. The connecting device according to the present invention allows use without changing the existing implanted spinal support, has a simple operation, and still has a satisfactory quality of the required rigid coupling. Due to its close proximity to the coupling means, in addition to the fact that the connecting device requires less space, the forces acting on the connecting device have only a small lever arm.

[0006] In a particularly preferred embodiment, the abutment is a lateral abutment on both sides. Thereby, an increase in the stability of the connecting device can be achieved with still satisfactory low material costs. If the extension direction of the spinal support to be extended is the longitudinal direction, the extension direction of the coupling means is the vertical direction, and the third spatial direction is the transverse direction which forms a plane together with the longitudinal direction, then the abutment of the bridging member can be seen in the projection of the plane, and the maximum dimension of the connecting device in the transverse direction is preferably less than 3 cm, preferably less than 2.7 cm, more preferably less than 2.4 cm, and particularly less than 2 cm.

[0007] Furthermore, it is preferably provided that the vertical height of the bridging member does not exceed 100% of the vertical height of the coupling means, preferably does not exceed 60%, and in particular does not exceed 30%. In another preferred embodiment, the vertical height of the upper end of the connecting device is not higher than the vertical height of the upper end of the bridging member. In the latter case, the bearing device does not require any space in addition to the space already existing in the vertical direction.

[0008] In a particularly preferred embodiment, the connecting device includes a third fastening means for fastening the connecting device to the first connecting rod at the free end on the connection side of the first connecting rod. This further increases the stability of the connection, because when observed in the longitudinal direction, the connecting device is fastened on both sides of the coupling means, and thus remains relatively stably fastened even in the case of accidental movement due to the unintentional loosening of one of the fastening means.

[0009] To avoid this, the clamping screw for the fastening device can be designed to be self-locking.

[0010] In another preferred design, in order to position the connecting device relative to the first spinal support, the first fastening device can be placed radially and in particular from above on the end region of the coupling device including the closest pedicle screw on the connecting side. Thus, the positioning during use can be achieved in a single placement step. In this case, the region adjacent to the coupling device can form a guide during placement.

[0011] In another preferred embodiment of the invention, the ability to place includes the ability of the first fastening device and / or the third fastening device to be clamped by means of (corresponding) elastic means. This again simplifies the attachment during use, since by clamping, a positioning that is already correctly positioned but can no longer be inadvertently detached from the connecting rod is provided without tools. In addition, the correct axial positioning has also been achieved by abutting, in particular in an almost complementary shape. In a preferred embodiment, the elastic means are designed such that one lateral boundary of the receiving region for receiving the first connecting rod and having the form of a receiving channel is formed by the inner surface of the elastic arm, and the other lateral boundary is formed by the side structure of the first fastening device on the opposite side (in the lateral / transverse direction), and this side structure serves the function of a fixed arm.

[0012] The invention also discloses aspects of such a simple establishment of positioning, which can be used independently and are worthy of protection, separate and independent from the design type of the rigid bridging piece with respect to abutment.

[0013] Accordingly, the invention also relates to a connecting device for connecting the end regions of an implanted first spinal support, wherein a plurality of pedicle screws are each connected to a first connecting rod at their cranial side by means of a coupling device, the connecting device comprising an implanted or non-implanted spinal support part having pedicle screws and extending the first spinal support, the connecting device comprising a first fastening device for fastening the connecting device to the first connecting rod and a coupling member for the extended spinal support part, the coupling member being in particular in the form of a second rod for the pedicle screws to be coupled to the extended spinal support part or in the form of a second fastening device for fastening the connecting device to such a second rod, wherein, in order to position the connecting device relative to the first spinal support, by means of the elastic means of the first fastening device and / or the clamping ability onto the first fastening device and / or the third fastening device caused by fastening to the other side of the coupling device, the first fastening device can be placed radially and in particular from above on the end region of the coupling device including the closest pedicle screw on the connecting side.

[0014] It is understood that the aforementioned and / or following other features of the connecting device can also be used jointly for such an independent variant of the clamping connecting device. The first connecting rod is preferably clamped to the first fastening device and / or the third fastening device by a clamping device that is part of the connecting device.

[0015] Herein, in particular, a clamping screw is provided, which is eccentrically arranged with respect to the receiving area of the first fastening device and / or the third fastening device that receives the first connecting rod. The clamping screw can be screwed into a threaded hole that does not extend into the receiving area, which is configured as a receiving channel for the first connecting rod. Thus, when the clamping screw is screwed in, the axial direction of the force application is no longer centered with respect to the middle of the connecting rod 60 as seen in the cross-section, and counteracts the spring action of the elastic device until it is counteracted and finally clamps the connecting rod in the area of the fastening device that receives it. For the latter, the elastic arm and the side structure of the first fastening device that assumes the function of the fixing arm preferably clamp the first connecting rod in the lateral direction that is orthogonal to the axial direction of the force application.

[0016] If the second rod for extending the spinal support has not yet become part of the connecting device, in a preferred embodiment, the second fastening device can be designed as a second rod that is axially inserted in its longitudinal direction and, in particular, is formed in a material block in the form of an axial hole. This allows the second rod to be axially pushed in, for example, when the connecting device has already been clamped. Then, the second rod can be fixed in the axial hole by a locking screw. It goes without saying that a lateral insertion option can also be envisaged, such as a U-shaped channel. The extension directions of the rods are preferably consistent, but an angled arrangement is also conceivable, especially a more complex coupling device that allows multi-axis angular adjustment.

[0017] In a preferred embodiment, the maximum lateral dimension of the connecting device is less than 1 / 3 of its axial dimension (calculated without an optionally implemented second rod), preferably less than 2 / 7 of its axial dimension, and / or less than 440%, especially 360%, of the diameter of the receiving area of the first connecting rod. If the stiffness of the bridging member has sufficient quality, a compact structure can be provided. By abutting against the bridging member, in a preferred embodiment of lateral abutment on both sides, a sleeve-like or band-like use can be produced, and the abutting part has a smaller lateral dimension compared to the already abutted part at the longitudinal point of the maximum lateral dimension. In a preferred embodiment of abutting by a sheath-like member, preferably, the wall thickness of the sheath wall in the area of the maximum lateral dimension of the connecting device is less than 40%, preferably less than 30%, and especially less than 20%, of the lateral dimension of the area surrounded by the sheath. The sheath-like part is preferably integrally connected to the first fastening device.

[0018] The present invention also provides an extension device for extending an already implanted first spinal support, comprising connection means according to any one of the foregoing aspects, and comprising at least one pedicle screw, a second rod (assuming the latter is not already optionally part of said connection means), and at least one coupling means for forming a rigid connection between said pedicle screw and said second rod.

[0019] Furthermore, the spinal support as a whole is also protected, the spinal support having a first spinal support and an extension, the first spinal support having a plurality of pedicle screws which are respectively connected to a first connecting rod at their cranial sides by coupling means, and the extension being connected by connection means according to any one of the foregoing aspects.

[0020] The present invention also protects a method for preparing such connection means so that they are about to be used for forming an extension of a first spinal support. This can include several aspects. First, the connection means (provided in any case) are designed from a material point of view of a biocompatible material (such as titanium, stainless steel or plastics, such as a biocompatible polymer, which are known to those skilled in the field of implantology), and obvious preparations are made through sterilization steps, such as autoclaving, proper assembly of the support rods matching the already implanted first spinal support and / or providing the assembled parts to the surgeon performing the implantation. Regarding the pedicle screws and their connection means on the rods, as known to those skilled in the art and mentioned several times in the present application, for example, referring to the techniques in WO2009 / 015100A2 or EP2581057B1, which are incorporated herein by reference.

[0021] Furthermore, it is also provided that a combination is provided having at least two, in particular at least four, connection means according to any one of the foregoing aspects, wherein the first fastening means of at least two connection means have different embodiments from each other so as to be fastened to connecting rods having different transverse dimensions so as to be able to be placed on coupling means of different sizes, and / or at least two connection means have second rods of different lengths. This classification enables a flexible response to the situation of an already implanted spinal support where it cannot be assumed that its parts have known and uniform dimensions, further increasing the flexibility of using the connection means. Description of the Drawings

[0022] Further features, details and advantages of the present invention will become clearer from the following description of the drawings, wherein:

[0023] Figure 1a is a perspective view of the connection means of the first embodiment;

[0024] Figure 1b is Figure 1aPlan view of the connecting device;

[0025] Figure 2a including a sectional view along Figure 1b section line A-A in;

[0026] Figure 2b including a sectional view along Figure 1b section line B-B in;

[0027] Figure 3a is Figure 1a top view of the connecting device in its connection use;

[0028] Figure 3b including a sectional view along Figure 3a section line A-A of;

[0029] Figure 3c including a sectional view along Figure 3a section line B-B in;

[0030] Figure 4 shows the connecting device of the second embodiment;

[0031] Figure 5a , 5b , 5c corresponds to the Figure 3a , 3b and 3c of this second embodiment; and

[0032] Figure 6 shows a connecting device known in the prior art. Detailed implementation mode

[0033] Figure 1a shows the connecting device 10 of the first embodiment in a perspective view. As can be seen in Figure 1a , the first fastening device 1 has a spring arm 1a and a hole 11 provided with threads (not shown) for screwing into a clamping screw (not shown). The first fastening device 1 is used to fasten the connecting device 10 to the connecting rod 60 of the spinal support ( Figure 3a ).

[0034] The connecting device 10 has a second fastening device 2 in the left end region of Figure 1a . This device has a hole 22 embedded in the material of the end region and extending longitudinally along the connecting device 10, and a threaded through hole 12 extending in the vertical direction and extending to the hole 22. In this way, a rod inserted into the hole 22 can be fixed by a locking screw (not shown) that is screwed into the threaded hole 12. The second fastening device 2 is thus used to fasten the rod 40 that forms part of the support, and the support extends the spinal support having the connecting rod 60, although Figure 3bOnly the rod 40 itself is shown. The intermediate region 5 between the first fastening device 1 and the second fastening device 2 has a sheath-like region 4 adjacent to the first fastening device 1, the interior 6 of which is cylindrical in this exemplary embodiment, with the cylinder axis extending in the vertical direction. As Figure 1a shown, the sheath-like region 4 is integrally connected to the first fastening device 1. In the connection use, the interior 6 houses a coupling device 80 that fixedly connects the pedicle screw 70 of the spinal support to its connecting rod 60. As can be seen from Figure 1a it, the first fastening device 1 and the second fastening device 2 are connected to each other through the intermediate region 5 to form a single component.

[0035] Between the sheath-like region 4 and the second fastening device 2, there is also a third fastening device 3 that has a spring arm 3a and a threaded hole 13. In this exemplary embodiment, its structure is the same as that of the first fastening device 1 and will be described below with reference to FIG. 2. The third fastening device 3, similar to the first fastening device 1, is used to fix the connecting device to the connecting rod 60 of the already implanted spinal support, but on the side away from the coupling device 80 of the first fastening device 1, at the free end of the connecting rod 60. The first fastening device 1 and the third fastening device 3 thus surround the coupling device of the spinal support to be extended in a sandwich-like manner, and the sheath-like region 4 or its side wall 48 abuts against the coupling device 80. As can be seen from Figure 1a it, the first fastening device 1 and the third fastening device 3 are connected to each other through the sheath-like region 4 to form a single entity.

[0036] As Figure 2a shown, in this exemplary embodiment, the receiving channel 16 for the connecting rod 60 extends axially centered and is almost coaxial with the hole 22. In the regions of the first fastening device and the third fastening device, in the unloaded state of the spring arms 1a, 3a, the opening of the channel 16 is slightly narrower than the diameter of the channel 16. Thus, through the elastic yielding of the elastic arms 1a, 3a, the fastening devices 1, 3 can be clamped onto the connecting rod 60, and during this clamping movement, the sheath-like region 4 slides on the coupling device 80.

[0037] The threaded holes 11 and 13 do not extend into the channel 16 (FIG. 2). In addition, as Figure 1b and Figure 2bAs shown, these elastic arms are arranged eccentrically with respect to the central axis of the connecting device 10 and move in the directions of the elastic arms 1a, 3a. Therefore, when the clamping screw is screwed in, the elastic action of the spring arms 1a, 3a is initially cancelled, and in this state, it prevents the connecting device 10 from being removed from the spinal support (rod 60) again. By further tightening or fixing the clamping screw, the connecting device 10 is rigidly and firmly connected to the connecting rod 60 of the implanted spinal support. Thus, the rod 40 of the extension section of this spinal support is also rigidly and firmly connected to the spinal support to be extended by the second fastening device 2. As Figure 2b shown, the thread of the hole 11 and the opposite side boundaries of the channel 16 are connected integrally with each other.

[0038] In this embodiment, the function of the first fastening device 1 is achieved in such a way that, when observed in the cross-section of the channel 16, its boundary is constituted by the inner surface of the elastic arm 1a on one side and by the side structure of the first fastening device 1 on the opposite side, which side structure has the function of the fixed arm 1b, and the two arms 1a and 1b are connected to each other only by a material bridge 1c with a small thickness. However, the material and dimensions of the material bridge 1c are matched to each other so as to prevent the elastic arm 1a from breaking under the accidental and unintentional application of force. As Figure 2b shown, the side boundaries 1a, 1b of the channel are opposite to each other with respect to the transverse or lateral direction, which is orthogonal to the threaded hole 11. As described above, the threaded hole 11 is not centered with respect to the lateral boundaries 1a, 1b, but is eccentrically arranged towards the spring arm 1a in the transverse direction.

[0039] In addition to the cross-sectional views shown, the components recognizable in the projection are also imaged in the illustration of FIG. 3, such as Figure 3c the pedicle screw 70 or the side region 48 of the sheath-like region 4 in Figure 3a so as to be able to recognize the relative positions of these parts / objects. It can be clearly seen from

[0040] The connecting device 10 can simply be clipped onto this end region without the need for end regions on the connecting rod 60 and / or the coupling device 80, and without loosening the locking screw 82 of the coupling device 80. The latter can be designed according to techniques used for many years, such as those described in WO 2009 / 015100A2 or EP2581057B1, for example a tulip screw, a saddle piece received in the tulip screw, in which the head of the pedicle screw 70 is received, and the screw 82 exerts a clamping pressure on the saddle piece via the connecting rod 60 in order to fixedly couple the screw 70, in particular designed as a multi-axis screw, in a desired angular position relative to the connecting rod 60. Then a similar system can also be used for the extended spinal support part of the rod 40.

[0041] When viewed from the vertical direction, as Figure 3b shown, the upper part of the connecting device 80 can be fully received inside the sheath-like region 4 in the interior 6. In this way, the relatively flat surface side of the connecting device can be formed in the deployed state.

[0042] For a person skilled in the art, it is obvious that for this embodiment, various alternative structural designs can be envisaged. For example, if an angled connection is required, the axes of the rods 40, 60 do not have to be collinear or even parallel. The second fastening device 2 can also be designed differently, for example similar to the first fastening device, or have a lateral insertion channel instead of the blind hole 22. The sleeve-like abutment can also be achieved by laterally clamping onto the connecting rod 60; for this purpose, the sheath-like region 4 must be modified to suit the lateral attachment. In a correspondingly rigid structure, one of the side arms 48 of the sheath-like region 4 can also be sufficient. The downwardly protruding flange-like end of the side wall 48 can be shorter or have a notch, for example, or the structure of the sheath-like region can be replaced by a ring structure corresponding to its upper region. In the case of a very short protruding free end of the connecting rod 60, variants are also considered in which the third fastening device is displaced to the side of the first fastening device or the first fastening device alone ensures sufficient coupling to the connecting rod 60.

[0043] Furthermore, the rod of the extension section can already be an integral part of the firmly coupled connecting device. This embodiment is shown schematically in Figure 4 It can be seen that in the connecting device 10' shown there, the rod 40' for extending the rod 60 has been connected integrally, for example, by a flange 2' adjacent to the third fastening device 3 of the connecting device 10'. As Figure 4 shown, the flange 2' and the first fastening device 1 are connected to form a single unit via an intermediate region 5. In this way, depending on the length dimension of the required extension part, connecting devices 10' with rods 40' of different lengths can also be provided. The remaining design of the connecting device 10' can correspond to Figure 1aThe design of the connecting device 10, in this regard, the same reference numerals are also used to denote equivalent components, and Figure 5a 、 5b and the representations in 5c functionally and structurally correspond to the representation of FIG. 3 of the first embodiment in this exemplary embodiment, and are exactly separated from the already provided rod 40'. It can be understood that a hybrid form can also be used. For example, the connection between the rod 40' and the flange 2' may not be formed integrally, but the rod 40'' can be screwed into the flange 2''.

[0044] In terms of materials, the components of the connecting device are made of biocompatible materials such as stainless steel, titanium or biocompatible polymers, as is known to those skilled in the art.

[0045] The method of preparing the connecting device for use may include a disinfection step and / or an autoclaving step, as well as the proper provision not only of the connecting device but also of the entire extended spinal support, which has a connecting rod 40 (40', 40'') of appropriate length and pedicle screws / coupling devices similar to the pedicle screws 70 and the coupling device 80 shown in FIGS. 3 and 5. For its specific design, conventional structures are available, such as those presented in the above-mentioned literature.

[0046] Therefore, the present invention is not limited to the embodiments described in the illustrated embodiments. On the contrary, the various features of the above description and the appended claims may be separate and / or combined for the implementation of the present invention in its various embodiments.

Claims

1. A connecting device for connecting an end region of an implanted first spinal support, wherein a plurality of pedicle screws (70) are each connected to a first connecting rod (60) at their cranial side by means of a coupling device (80), the connecting device comprising an implanted or non-implanted spinal support part having pedicle screws and extending the first spinal support, the connecting device comprising: a first fastening device (1) for fastening and clamping the connecting device to the first connecting rod (60), and a coupling member for the extended spinal support part, the coupling member being in the form of a second rod for a pedicle screw to be coupled to the extended spinal support part or in the form of a second fastening device (2) for fastening the connecting device to such a second rod, characterized in that a rigid bridging member (5) in an intermediate region between the first fastening device and the coupling device of the connecting device, which bridging member laterally abuts on the coupling devices (80) of the closest pedicle screws (70) of the implanted first spinal support on both sides of the connection side; for positioning the connecting device relative to the first spinal support, the first fastening device (1) can be radially and from above placed on an end region of the coupling device (80) including the closest pedicle screw (70) on the connection side by means of an elastic device; the elastic device is designed such that one lateral boundary of a receiving region for receiving the first connecting rod (60) and being in the form of a receiving channel is formed by the inner surface of an elastic arm, and the other lateral boundary is formed by a side structure of the first fastening device on the opposite side, which side structure functions as a fixed arm; when a clamping screw is screwed into a threaded hole not extending into the receiving region, the axial direction of the force application is no longer centered relative to the middle of the first connecting rod (60) as seen in cross-section, and the clamping screw is eccentrically arranged relative to the receiving region.

2. The connecting device according to claim 1, characterized in that it comprises a third fastening device (3) for fastening the connecting device to the first connecting rod (60) at its free end located on the connection side.

3. The connecting device according to claim 2, characterized in that the third fastening device (3) can be clamped by means of an elastic device.

4. The connecting device according to claim 2, characterized in that it further comprises a clamping device for clamping the first connecting rod (60) to the third fastening device (3).

5. The connecting device according to claim 2, characterized in that it further comprises a clamping screw, which is eccentrically arranged relative to a receiving region of the third fastening device for receiving the first connecting rod (60).

6. The connecting device according to claim 1, characterized in that the second fastening device (2) is designed for axially inserting the second rod along its longitudinal direction and is formed as an axial hole in a material block.

7. The connecting device according to claim 1, characterized in that The connecting device is designed for a substantially collinear relative positioning of the first connecting rod (60) and the second rod.

8. The connecting device according to claim 1, characterized in that the maximum lateral dimension of the connecting device is less than 1 / 3 of its axial dimension, and / or less than 440% of the diameter of the receiving area of the first connecting rod, the axial dimension being calculated without the second rod not being implemented.

9. The connecting device according to claim 8, characterized in that the maximum lateral dimension of the connecting device is less than 2 / 7 of its axial dimension, and / or less than 360% of the diameter of the receiving area of the first connecting rod.

10. An extension device for extending an already implanted first spinal support, characterized in that it comprises a connecting device according to any one of claims 1 to 9, and comprises at least one pedicle screw, a second rod and at least one coupling device, the second rod already being part of the connecting device, the at least one coupling device forming a rigid connection between the pedicle screw and the second rod.

11. A method for preparing the extension device according to claim 10, characterized in that the extension device is made of a biocompatible material for its intended use of forming an extension of the already implanted spinal support.

12. A spinal support, characterized in that it has a first spinal support with a plurality of pedicle screws and an extension piece connected by a connecting device according to any one of claims 1 to 9, the pedicle screws being respectively connected to a first connecting rod (60) by coupling devices (80) at their cephalic side.

13. A combination having at least two connecting devices according to any one of claims 1 to 9, characterized in that the first fastening devices of the at least two connecting devices have different embodiments from each other in order to be fastened to connecting rods with different lateral dimensions so as to be able to be placed on coupling devices of different sizes, and / or the at least two connecting devices have second rods of different lengths.

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