Flexible connector for connecting rods of a spine stabilisation system and spine stabilisation system

Abstract

The invention relates to a connector device (1) which is provided and designed to couple at least two rods of a spine stabilisation system to one another in a selected or selectable relative position and / or relative orientation, for which purpose the connector device (1) has at least the following components: a first rod receiving housing (6), which forms or comprises a first receiving shaft for receiving a first rod (4) and a first internal rod fixation (28), preferably in the form of a clamping screw, clamping collar or clamp; a second rod receiving housing (7), which forms or comprises a second receiving shaft for receiving a second rod (5) and a second internal rod fixation (30), preferably in the form of a clamping screw, clamping collar or clamp, which is formed separately to the first rod fixation (28) and can be actuated independently thereof; and a preferably lockable articulated coupling (12), which couples the first and second rod receiving housings (6, 7) to one another and is provided and designed to allow a rotation of the articulation about three mutually perpendicular axes.

Description

[0001] Flexible connector for connecting rods of a spinal stabilization system and spinal stabilization system

[0002] Description

[0003] Technical area

[0004] The present disclosure relates to a flexible connector for connecting rods of a spinal stabilization system.

[0005] Background of the invention

[0006] Spinal stabilization systems are primarily used for dorsal stabilization of the spine in cases of fractures, tumors, inflammation, deformities, and degenerative instabilities. Implant screws are placed in the sacrum or iliac region, or in the pedicles of adjacent vertebrae, and an angularly stable connection is created between the implant screws via at least one rod. The implant screws and the at least one rod thus form a spinal stabilization system.

[0007] Rod connectors can be used, for example, to expand an existing (spinal) construct in the event of a revision operation, to create a new multi-level construct, or to connect to an offset screw. A variety of rod connectors and rod connector designs are available for each specific case. In addition to domino rod connectors and axial rod connectors, there are lateral offset connectors in various lengths that enable a connection to the pelvis. To enable a connection to the pelvis / sacrum or to compensate for an offset, lateral offset connectors in various lengths are also used.

[0008] The implant screws are anchored by a surgeon into the vertebra, etc. The implant screws have an axial external thread shaft, to which a receiving sleeve, also known as a tulip, is attached dorsally. At least one rod is attached to this sleeve once the implant screws are inserted. A rod of the correct length is selected and, if necessary, its curvature is adjusted to the implant screws and their respective positions, or rods are combined to accommodate specific anatomical requirements.

[0009] For example, if a sacral implant screw and an implant screw (pedicle screw) screwed into a lower vertebra are to be securely connected, it may happen that the screw heads are not aligned, resulting in two rods that are inclined to each other or angled at up to 90° to each other being connected via a connector. It is important that the two rods in question can vary in their relative position and then be secured in a desired position, i.e., locked against further movement.

[0010] State of the art

[0011] Various connectors for connecting two rods are known. The two rods can first be moved and pivoted relative to each other and then secured together. Such connectors are called flexible connectors. They can be used to expand an existing spinal stabilization construct in the event of revision surgery, to create a new multi-level construct, or to connect to an offset screw.

[0012] US 8,430,916 B1 discloses a flexible connector with a main body designed to accommodate both respective rods. A ball joint is provided between the first rod and the main body, while the second rod is directly received in a clamp or clip formed integrally in the main body. A central screw fastens all components—the first rod with the ball joint to the main body and the second rod in the clamp or clip of the main body—to the flexible connector. In a basic position of the flexible connector, in which the ball joint is not pivoted, the two rods are parallel to each other, and the first rod can be pivoted from this basic position within the limits of the ball joint.

[0013] The disadvantage of this connector is the limited flexibility in positioning the two rods. Given the parallel arrangement of the two rods, the connector is only suitable for pivoting the first rod by up to 15°.

[0014] Flexible connectors are also known that allow the two rods to be positioned at right angles.

[0015] The Expedium system from Depuy features flexible connectors for connecting two rods. These connectors consist of two elements for receiving and securing a rod. The two elements rotate relative to each other around a pivot axis. This allows the two rods to be pivoted relative to each other and then secured in a selected pivot position.

[0016] In a connector in the Solera system from Medtronic, two elements can be rotated against each other in a similar way around a rotation axis and can then be secured against further rotation by means of a toothing running around the rotation axis.

[0017] The disadvantage of such flexible connectors, in which a separate element is provided for each rod, is the limited mobility of the two elements relative to each other and thus the limited final positioning of the two rods relative to each other.

[0018] Brief description of the invention

[0019] The object of the present disclosure is to create a connector for rods and a rod arrangement of a spinal stabilization system, or a corresponding spinal stabilization system, with maximum flexibility during surgery. In particular, extreme angles between the rods, such as a right angle, should also be possible.

[0020] This object is achieved by a connector for a spinal stabilization system having the feature combination of claim 1 or by an arrangement / a spinal stabilization system having the feature combination of claim 12.

[0021] This object is achieved by a connector device (hereinafter also referred to as connector) which is intended and designed to couple at least two rods of a spinal stabilization system in a selected or selectable relative position and / or relative orientation, for which the connector device has at least the following components:

[0022] - a first rod receiving housing (hereinafter also referred to as the first element), which forms or has a first receiving shaft (hereinafter also referred to as the first receptacle) for receiving a first rod and has a first internal rod fixation (hereinafter also referred to as the first fastening device), preferably in the form of a clamping screw, clamping collar or clamp,

[0023] - a second rod receiving housing (hereinafter also referred to as the second element), which forms or has a second receiving shaft (hereinafter also referred to as the second receptacle) for receiving a second rod and has a second internal rod fixation (hereinafter also referred to as the second fastening device), preferably in the form of a clamping screw, clamping collar or clamp, which can be actuated separately from and independently of the first rod fixation, and

[0024] - a preferably lockable articulated coupling (hereinafter also referred to as a 3D rotary coupling), e.g. with at least one joint / in particular a ball joint, which couples the first and second rod receiving housings to one another and is provided and designed to effect a joint rotary movement about three mutually perpendicular axes. In other words, the connector according to the disclosure is designed and configured for two rods of a spinal stabilization system. The connector has a first element that has a first receptacle with a first fastening device for a first rod of the spinal stabilization system. The connector further has a second element that has a second receptacle with a second fastening device for a second rod of the spinal stabilization system.The two elements are pivotally coupled to each other by means of a joint coupling, particularly a lockable joint, pivotable about three orthogonal axes, in particular with at least one ball joint. Starting from a basic position, which will be defined more precisely later, the 3D rotary coupling / ball joint is preferably freely pivotable in all directions, e.g., up and down and right and left, e.g., by at least 20°.

[0025] The relative position of the bars refers to their position relative to each other, without taking their angle to each other into account, i.e., the position of a fixed point (e.g., end point or center point) of the bars relative to each other. Relative alignment refers to the angular or rotational orientation of the bars relative to each other, without taking their relative position to each other into account.

[0026] A preferred embodiment is a multi-part connector which has a joint with which it is possible to more easily accommodate two or more rods at different angles and to lock the given position.

[0027] In a first embodiment of the invention, the two elements are coupled to one another or to one another or to one another by means of the articulated coupling with a (single) 3D swivel joint (i.e., a joint that enables rotation about three orthogonal axes) / ball joint and, in a preferred second embodiment, with two 3D swivel joints / ball joints. More than two 3D swivel joints / ball joints connected in series can also be provided. In particular, the ball joint has a blocking device. The blocking device is preferably designed separately from the first and / or second fastening device and can be actuated separately therefrom. The at least one 3D swivel joint / ball joint preferably comprises a (respective) blocking device. This makes it possible to achieve a large pivoting range of one element relative to the other element and thus of one rod relative to the other rod.Particularly in the embodiment with the two 3D swivel joints / ball joints, a large pivoting range is possible. Due to the separate elements, even extreme angles, such as a right angle between the main axes of the first and second elements or between the two rods (e.g., even when these are inserted into blind holes in the first and second elements), can be achieved by appropriately arranging the rod mounts. This design opens up new possibilities in the treatment of spinal disorders and in meeting the challenges of everyday clinical practice.

[0028] In other words, a flexible spinal connector can be provided for connection to a sacral screw connection of a spinal implant. In other words, a spinal concept for a new connector (the connector according to the disclosure) lies in creating the possibility of connecting rods (first and second rods) that are at a specific angle to one another. The angle between the rods can be addressed / adjusted by a joint in the connector and, in particular, fixed in this position. In this case, the connector can have two elements (the first and second element) that are mounted to one another with a 3D rotary coupling / a 3D rotary joint / ball joint. By applying a force to the 3D rotary joint, e.g., a ball of the ball joint, the two elements can be clamped together. This way, the alignment of the connector elements to one another can be fixed.

[0029] In other words, the present application relates to a novel rod connector, more specifically, a multi-part connector having a joint that makes it easier to accommodate two rods at different angles and to lock the given position. This makes it possible to flexibly adjust the angular position of two rods and, in particular, to accommodate rods that are orthogonal to one another. In particular, the articulated coupling has a joint head portion and a joint head receptacle in which the joint head portion is held. Further, in particular, the joint head receptacle is constrictable in order to clamp the joint head portion in the joint head receptacle and block its mobility in the receptacle.

[0030] The first fastening device is preferably formed by a first clamping screw, in particular a grub screw that can be countersunk into the first element. The second fastening device is preferably formed by a second clamping screw, in particular a grub screw that can be countersunk into the second element.

[0031] According to the disclosure, the 3D rotary coupling preferably has a ball joint. Further preferably, an insert (e.g., sleeve-shaped or bolt-shaped) is arranged between the first receptacle for the first rod and a 3D rotary joint section, in particular a ball section of the ball joint, fastened or formed on the second element. The insert can be clamped against the 3D rotary joint section, in particular a ball section, by means of the first fastening device / clamping screw, directly or indirectly (e.g., by applying force to the insert), in order to block it. Preferably, a section of the insert facing the 3D rotary joint section / ball section / ball head, in particular an end face, forms an inclined or spherical surface, in particular a section of a hollow spherical surface, the dimensions or diameter of which essentially correspond to the dimensions or diameter of the 3D rotary joint section or ball section.

[0032] In other words, the joint head receptacle can be formed in the first rod receptacle housing. Furthermore, the joint head receptacle can be connected to the first receiving shaft for the first rod. Furthermore, an insert part, in particular a sleeve- or bolt-shaped insert part, can be movably inserted into the first rod receptacle housing along a first central axis such that one end of the insert part is arranged in or on the joint head receptacle in order to directly or indirectly contact the joint head. Furthermore, another end of the insert part can border on or protrude into the first receiving shaft in such a way that the insert part can be clamped directly or indirectly against the joint head via the first rod, preferably by means of the first rod fixation, in particular a first clamping screw, in order to block it.

[0033] This means that one connector part (second element) preferably has a 3D swivel head / ball head, which is connected to another connector part (first element). The other connector part preferably contains an insert (insert part / insert), with which the 3D joint connection / ball connection (the ball joint) can be blocked. If, for example, a rod (second rod) is inserted into the other connector part and locked, it is pressed against the insert, which blocks the joint through the particularly flat pressure against the 3D swivel head / ball. This allows the connector to be fixed in any angular position as soon as the rods of the spinal construct have been inserted into the connector and locked.

[0034] For this purpose, the insert part is preferably guided in a through-hole of the first element. If the insert part and the through-hole are rotationally symmetrical to a first central axis of the first element, the manufacture and assembly of the first element and the insert part are simplified and the result is a particularly annular contact of the insert part with the 3D swivel head / ball section. Preferably, the first element forms a 3D swivel head / ball section receiving space which, at its exit, has an inclined or spherical contact surface for the 3D swivel head / ball section, in particular a section of a hollow spherical surface whose dimensions / diameter essentially correspond to a diameter of the 3D swivel head / ball section.

[0035] At the end portion of the clamping screw facing the first rod, an inclined, e.g., conical or spherical rod support is formed, which can be brought into contact with the first rod. In a first embodiment of the connector that is simple in terms of manufacturing technology, a screw direction and / or a screw hole of the first clamping screw is arranged perpendicular to the first central axis. This is advantageous because it allows an opening in the receptacle, through which the first rod can be inserted into the receptacle, to be designed as large as possible, making insertion of the first rod easy.

[0036] In a second embodiment of the connector with improved force development when clamping the first rod and the insert part against the 3D swivel head / ball section, a screw direction and / or a screw hole of the first clamping screw is set at an angle of more than 90°, preferably between 110° and 140°, e.g. between 120 and 130°, to the first central axis. This is advantageous because it optimizes the force introduction via the first clamping screw onto the 3D swivel head / ball head and / or the insert part without the opening of the receptacle becoming too small for inserting the first rod. In other words, it is possible to design the connector such that the force introduction of the clamping screw is better directed towards the insert by designing the other connector part (the first element) at an angle.

[0037] In order to be able to assemble this embodiment (e.g. ball head in another connector part), it is possible, for example, to first insert the 3D swivel head / ball head and the insert into the connector and then to angle the other connector part by bending it and then to harden the part.

[0038] A method for producing a connector as described above, comprising the steps of:

[0039] - Providing a first element with a receptacle, which in one direction has a preferably annular contact surface for the 3D swivel head / ball element and in an opposite direction has an opening for inserting the 3D swivel head / ball section and the insert part, wherein the element further has, adjacent to the opening, a preferably tab-shaped clamping screw holding section with a through hole / screw hole for the first clamping screw; - subsequently inserting the 3D swivel head / ball section and the insert part into the opening;

[0040] - subsequently bending the clamping screw holding section towards the opening so that an angle greater than 90°, preferably 110-140°, more preferably 120-130°, is created between the axes of the receptacle and the through-hole / screw hole; and

[0041] - prefers subsequent hardening of the first element.

[0042] If a neck is provided between the second element and the attached 3D swivel head / ball section, then the swivel range of the 3D swivel / ball joint can be maximized, e.g. to a swivel range of up to 25° in all directions.

[0043] Since the neck of the second element must be guided through the through-hole of the first element during assembly of the connector, it is advantageous if the neck with the 3D swivel head / ball section formed on it is attached to the second element via a thread.

[0044] From an assembly point of view, it is simple if a contact collar is formed between the neck and the thread, which rests against the second element.

[0045] At least the second receptacle can be designed as a blind hole in the second element, into which the second rod can preferably be inserted axially / along a blind hole axis.

[0046] The second receptacle can also have a (second) clamping screw as the second fastening element, which is preferably also a grub screw that can be countersunk into the second element. Assembly is simple and cost-effective if the first clamping screw and the second clamping screw are identical.

[0047] From a manufacturing point of view, it is simple if the 3D swivel head / ball section and / or the neck and / or the thread and / or the contact collar and / or the blind hole are rotationally symmetrical to a common second central axis of the second element.

[0048] A basic position of the connector or its elements is defined by the fact that the first central axis (of the first element) coincides with the second central axis (of the second element). This means that the 3D joint coupling, in particular the 3D swivel joint / ball joint, is aligned straight and, starting from this basic position, can be pivoted in all directions, in particular essentially equally far in all directions.

[0049] At least the first receptacle can be designed as a clamp in the first element, or the first element can be formed by a clamp. In conjunction with the blind hole of the second element, a highly angled arrangement, e.g., 90°, of the two affected rods can be realized in the basic position of the connector or its elements. Starting from this, the pivoting range enabled by the 3D joint coupling / 3D swivel joint / ball joint can be utilized. This means that in a basic position in which the affected rods are at 90° to each other, a maximum pivoting range is possible.

[0050] The assembly according to the disclosure is part of a spinal stabilization system and has a connector as described above and a first rod inserted into the first receptacle of the first element. The insert part is clamped indirectly via the first rod against the 3D swivel head / ball section by means of the first clamping screw, thereby securing or fastening the first rod in the first receptacle of the first element.

[0051] Preferably, the joint head receptacle has a screw element, in particular a union nut, which can be screwed into or onto the joint head receptacle in order to narrow the joint head receptacle directly or indirectly and to clamp the joint head section.

[0052] In other words, in a particularly preferred embodiment of the one exemplary embodiment with the one (single) 3D swivel joint / ball joint, the blocking device has a screw element, in particular a union nut, by means of which a 3D swivel head / ball section of the 3D swivel jointZ ball joint fastened to the first element can be clamped and / or firmly clamped in a 3D swivel head receptacleZ ball receptacle fastened or formed on the second element. The screw element is attached directly to the 3D swivel head receptacle in order to selectively narrow or widen it by screwing the screw element in order to clamp or release the 3D swivel head therein accordingly. The screw element / union nut can engage with its (internal) thread with an (external) thread of the second element.In other words, the connector features a 3D swivel / ball joint, which can be locked by a screw element / union nut. This allows the connector to be fixed in any angular position once the rods of the spinal construct have been inserted into the connector.

[0053] As already mentioned above, the connector can be designed so that two union nuts and also two 3D swivel joints, in particular ball joints, are present. This means that an intermediate element is provided which has two 3D swivel joint sectionsZ ball joint sections, which can each be connected to the 3D swivel joint sectionZ ball joint section of one of the two elements (first or second element) in order to form one of the 3D swivel jointsZ ball joints. The intermediate piece can, for example, form two receptacles for 3D swivel headsZ ball sections of the first and second element, or can serve two 3D swivel headsZ ball sections, e.g. with union nuts, for engagement in corresponding receptacles on the first or second element, or can form a corresponding ball section and a corresponding receptacle for a 3D swivel headZ ball section.In this way, a particularly high level of flexibility can be achieved when combining different elements and, if necessary, quantities of the same elements can be increased in order to save costs.

[0054] In the corresponding particularly preferred embodiment of the other exemplary embodiment with the two 3D swivel joints / ball joints, the two blocking devices each have a screw element / union nut as described above, by means of which a 3D swivel head section / ball section of the respective 3D swivel joint / ball joint, fastened to the respective element, can be clamped and / or secured in a respective 3D swivel head receptacle / ball receptacle of a component arranged between the elements. The two screw elements / union nuts engage, with their respective (internal) threads, a respective (external) thread of the component. The component is preferably sleeve-like or a sleeve part.

[0055] Preferably, the joint head section is fastened to the first rod receiving housing via a neck, in particular via a thread formed on the neck, or integrally connected thereto, in particular by welding, wherein the neck is preferably encompassed by a clamping collar of the screw element designed as the union nut.

[0056] In other words, in one exemplary embodiment, the 3D swivel headZ ball section is preferably fastened to the first element via a neck. The neck is preferably enclosed by a clamping collar (i.e. a radially inwardly extending projection for engagement with the 3D swivel head section / ball section) of the screw element in the form of a union nut, which clamping collar is arranged between the first element and the 3D swivel head section / ball section, as viewed along a central axis. The clamping collar is preferably in engagement with the 3D swivel head section / ball section. The narrower or thinner the neck is in relation to the 3D swivel head section / ball section, the greater the pivoting range of one element relative to the other element and thus of one rod relative to the other rod.

[0057] Preferably, the 3D swivel head section / ball section and optionally the neck are formed integrally with the first element, e.g. as an injection-molded part. Preferably, the ball section has a thread on its radial outer surface, via which the union nut can be screwed onto the ball section. This means that, in particular, the 3D swivel head section can be formed in the form of the ball section, and the ball section can form a thread on its radial outer surface, via which the union nut can be screwed onto it. Alternatively, the 3D swivel head section / ball section can preferably be welded to the first element via the neck or screwed to the neck via a thread. In other words, for the manufacture and assembly of the connector, the connector part can be welded to the 3D swivel head / ball (ieThe first element (e.g., the first element with the 3D swivel head section / ball section) can be connected by a thread or welded on so that the union nut can be mounted. Alternatively, the connector part on which the union nut sits (especially the first element with the 3D swivel head section / ball section) does not necessarily have to be two-part to allow for the union nut to be mounted. For example, the ball element can have a thread over which the nut is mounted.

[0058] In the other embodiment, the two 3D swivel head sections / ball sections are preferably attached to the respective element via a respective neck. The two necks are enclosed by a respective clamping collar of the respective union nut. The necks are arranged - viewed along a central axis - between the respective element and the respective 3D swivel head section / ball section.

[0059] From a design and manufacturing perspective, it is optimal if the neck extends along a concentric center axis of the union nut when the two elements are in a home position. In the embodiment with the two 3D swivel joints / ball joints, both necks preferably extend along a concentric center axis of the two union nuts when the two elements are in a home position relative to each other. This means that the home position is defined by the 3D swivel joint / ball joint being aligned straight and, starting from this home position, being pivotable in all directions, in particular essentially the same distance in all directions.

[0060] The 3D swivel head receptacle / ball receptacle requires a counterbearing against which the 3D swivel head section / ball section is clamped when the screw element / union nut is closed. The ball receptacle preferably has an inner wall, in particular a receptacle base wall, or a circumferential conical inner wall, against which the ball section can be clamped directly or indirectly by means of the screw element, preferably the union nut.

[0061] In other words, the 3D swivel head receptacle / ball receptacle can have a central inner wall that serves as a counterbearing and against which the 3D swivel head section / ball section can be clamped by the screw element, in particular the clamping collar of the union nut. Preferably, the wall is perpendicular to the central axis. In the embodiment with the two 3D swivel joints / ball joints, each 3D swivel head receptacle / ball receptacle preferably has a central inner wall of the common component, against which the respective 3D swivel head section / ball section can be clamped by the associated screw element or the clamping collar of the associated union nut.

[0062] Alternatively, the 3D swivel head receptacle / ball receptacle can also have or be a circumferential conical wall of the second element, which serves as a counterbearing. The 3D swivel head section / ball section can then be clamped against or into the circumferential conical wall by the screw element / clamping collar of the union nut. The wall is preferably concentric to the central axis. In the embodiment with the two 3D swivel joints / ball joints, the 3D swivel joint receptacles / ball receptacles each have or are preferably a circumferential conical wall of the common component, against or into which the respective 3D swivel head section / ball section can be clamped by the respective screw element / clamping collar of the respective union nut.

[0063] The two receptacles for the rods can be designed in a mechanically stable manner as through holes or as blind holes in the respective element. The direction in which the rod can be inserted can vary. The through hole or through holes can be arranged transversely to the central axis in the basic position. The blind hole or blind holes can extend along the central axis in the basic position. In other words, at least one of the first and second rod receiving housings can have a through hole for receiving the respective first or second rod, which runs in particular obliquely or transversely to a joint axis between the first and second rod receiving housings. Alternatively or additionally, at least one of the first and second rod receiving housings can have a blind hole for receiving the respective first or second rod, which runs in particular parallel to the joint axis or extends towards the articulated coupling.

[0064] In a specific embodiment of the connector, one of the two receptacles is designed as a through hole in the first or second element, while the other receptacle is designed as a blind hole in the second or first element. This makes it possible for the two elements to already have an angle of 90° between the two rods in their basic position. The large pivoting range around the basic position is provided by the at least one 3D swivel / ball joint.

[0065] Instead of the through-hole, a laterally open claw or forceps can also be provided. In this case, the affected rod can also be inserted laterally, which can have advantages when assembling the spinal stabilization system during surgery. In other words, the first and / or second receptacle for the first and / or second rod can be designed as a U-shaped receptacle. In particular, the U-shaped receptacle or claw / forceps can be open on a side on which the receptacle for the 3D swivel head section / ball section or the 3D swivel head section / ball section is not formed.

[0066] If the receptacle is a blind hole, only one end section of the rod can be secured there. If the receptacle is a through hole, a claw, or a pliers, then one end section or even a middle section of the rod can be secured there. Each receptacle preferably has a clamping screw to clamp the respective rod firmly in the receptacle. The clamping screws are preferably countersunk grub screws in the element. In the case of a through hole and a blind hole, the clamping screw is preferably arranged transversely to the hole and / or intersects an imaginary central axis of the hole.

[0067] Also disclosed is an arrangement wherein the two rods are attached to one another via a previously described connector and fixed in position relative to one another. That is, an arrangement according to the disclosure for a spinal stabilization system has a previously described connector and two rods, wherein the first rod is fixed or secured in the first receptacle, and wherein the second rod is fixed or secured in the second receptacle.

[0068] Also disclosed is a spinal stabilization system with such an arrangement and with a first implant screw, to whose receiving sleeve (tulip) the first rod of the arrangement is fixed or secured, and with a second implant screw, to whose receiving sleeve (tulip) the second rod of the arrangement is fixed or secured. This means that a spinal stabilization system according to the disclosure has a first implant screw, to whose receiving sleeve (tulip) a first rod can be fixed or secured. The system further comprises a second implant screw, to whose receiving sleeve (tulip) a second rod can be fixed or secured. The two rods can be fastened to one another and fixed in position relative to one another via a connector as described above.

[0069] In other words, a spinal stabilization system is disclosed, comprising a connector device according to one of the preceding claims and comprising a first rod which is inserted or insertable into the first rod receiving housing, and a second rod which is inserted or insertable into the second rod receiving housing, preferably further comprising a first implant screw and a second implant screw, each having a screw head portion with a tulip or receiving sleeve for receiving and securing the first or second rod, respectively. Brief description of the figures

[0070] Fig. 1 is a spinal stabilization system with a connector according to a first embodiment of the present disclosure;

[0071] Fig. 2 is a sectional view of the connector of Fig. 1;

[0072] Fig. 3 is a perspective view of a connector according to a second embodiment of the present disclosure;

[0073] Fig. 4 is a perspective view of a connector according to a third embodiment of the present disclosure;

[0074] Fig. 5 is a perspective view of a connector according to a fourth embodiment of the present disclosure;

[0075] Fig. 6 is a perspective view of a connector according to a fifth embodiment of the present disclosure; and

[0076] Fig. 7 is a cross-sectional view of a variation of the ball joint of the connectors of the present disclosure.

[0077] Fig. 8 is a perspective view of a two-rod, one-connector assembly according to a sixth embodiment of the present disclosure;

[0078] Fig. 9 is a sectional view of the connector and rod assembly of Fig. 8;

[0079] Fig. 10 is a sectional enlarged view of a portion of the sixth embodiment of the connector of Fig. 9; Fig. 11 is a sectional view of an assembly with two rods and a connector according to a seventh embodiment of the present disclosure.

[0080] Description of the embodiments

[0081] Several embodiments of the present disclosure will be described below based on the accompanying figures.

[0082] Fig. 1 shows a spinal stabilization system with a flexible connector 1 according to a first embodiment. The spinal stabilization system can alternatively have any other connector 1 according to the disclosure. The construct has (top in Fig. 1) an implant screw used as a pedicle screw and (bottom in Fig. 1) a sacral implant screw, with only one respective receiving sleeve 2, 3 of each implant screw being shown. A first rod 4 is inserted into the receiving sleeve 2 of the sacral implant screw, while a second rod 5 is inserted into the receiving sleeve 3 of the pedicle screw.

[0083] The implant screws have, in particular, a screw shaft which extends along a longitudinal screw axis and at one (dorsal) end of which a shaft head is formed, to which the receiving sleeve 2, 3 (tulip) is mounted. The shaft head and the receiving sleeve 2, 3 preferably form a joint, such that the receiving sleeve 2, 3 is pivotable relative to the screw shaft. The receiving sleeve 2, 3 forms a rod insertion opening (i.e., a section for receiving or holding a rod), which is designed to receive the rod 4, 5 lying transversely to the central axis of the receiving sleeve. In particular, the rod insertion opening extends transversely to the central axis through the receiving sleeve 2, 3 and opens on both diametrically opposite sides of a peripheral wall of the receiving sleeve 2, 3.Furthermore, the rod insertion opening is open toward an end face of the receiving sleeve 2, 3 opposite the screw shaft, so that the rod 4, 5 can be inserted into the rod insertion opening from the end face. In other words, the receiving sleeve 2, 3 forms two notches in its peripheral wall, which are diametrically opposite with respect to the central axis and extend from a proximal / dorsal end face of the receiving sleeve toward the screw shaft to form the rod insertion opening.

[0084] An inner circumferential surface of the receiving sleeve 2, 3 in an area between the notches or at a proximal / dorsal end area of ​​the receiving sleeve 2, 3 forms an internal thread. The internal thread is suitable for screwing in a setscrew or grub screw (not shown) to fix an inserted rod 4, 5 in the receiving sleeve 2, 3 and / or to clamp the receiving sleeve 2, 3 against the shaft head to fix their position relative to each other.

[0085] The two rods 4, 5 are firmly connected to each other in the position shown by means of the flexible connector 1. For this purpose, the end section of the first rod 4 is inserted into a receptacle of a first element 6, designed as a through hole 8, while the end section of the second rod 5 is inserted into a receptacle of a second element 7, designed as a blind hole 10. The two rods 4, 5 can be inserted into the respective holes 8, 10 with a clearance fit and are then clamped in place.

[0086] In the structure shown in Fig. 1, the two rods 4, 5 are positioned at an angle of less than 90 degrees to each other. This is made possible in particular by the arrangement of the two holes 8, 10, but also by a ball joint between the two elements 6, 7. Furthermore, in the structure shown, the imaginary axes of the two rods 4, 5 do not intersect. This is made possible in particular by the ball joint between the two elements 6, 7.

[0087] Figures 2 to 5 show the respective connector 1 in its so-called basic position, in which the two elements 6, 7 are arranged relative to one another in such a way that a neck 26 of the first element 6 extends along a central axis 24 of a union nut 18.

[0088] Fig. 2 shows the connector 1 from Fig. 1 in a sectional view. The ball joint 12 can be seen, which has a ball portion 14 inserted into a ball socket 16 and is clamped there by means of the union nut 18. More precisely, the ball portion 14 is clamped against an inner wall 22 of the ball socket 16 by means of a clamping collar 20 of the union nut 18, which forms an annular contact with the ball portion 14. The inner wall 22 is aligned perpendicular to the central axis 24 of the union nut 18 and has a point contact with the ball portion 14, wherein the point contact lies on the central axis 24. The ball socket 16 with the inner wall 22 is formed integrally with the second element 7. The union nut 18 engages with an outer circumference of the ball socket 16 by means of a thread (not shown).

[0089] The ball portion 14 is attached to the first element 6 via the neck 26. The neck 26 is concentrically encompassed by the clamping collar 20 of the union nut 18 in the illustrated (above-explained) basic position of the connector 1.

[0090] Since the inside diameter of the clamping collar 20 is smaller than the diameter of the ball section 14, the ball section 14 or its neck 26 can only be attached to the first element 6 after the union nut 18 has been fitted. This can be done by welding or by threaded engagement.

[0091] The through hole 8 formed in the first element 6 is aligned transversely to the central axis 24 in the initial position, whereby an imaginary central axis of the through hole 8 and the central axis 24 do not intersect. The blind hole 10 formed on the second element 7 is concentric to the central axis 24.

[0092] Transverse to each hole 8, 10, a through-recess is provided in the respective element 6, 7, into which a clamping screw 28 designed as a grub screw is inserted and clamps the respective rod 4, 5 in the respective hole 6, 7.

[0093] Since the diameter of the neck 26 is at most 80%, in the illustrated embodiment approximately 75%, of the inner diameter or clear width of the clamping collar 20, the neck 26 with the first element 6 can be pivoted comparatively far in all directions starting from the basic position shown in Fig. 2, whereby the two rods 4, 5 (shown in Fig. 1) can be pivoted comparatively far in all directions starting from the basic position. The basic position of the two rods 4, 5 is defined by the arrangement and / or selection of the two holes 8, 10. Figures 3 to 5 show such variations of the holes 6, 7, wherein the respective ball joint 12 corresponds to that of the first embodiment according to Fig. 2.

[0094] Fig. 3 shows a perspective view of a connector 1 according to a second embodiment. The first element 6 has a blind hole 10, while the second element 7 has a through hole 8. An imaginary central axis of the through hole 8 intersects the central axis defined by the union nut 18 (see Fig. 2) at right angles. With this connector 1, a basic position of the two rods concerned of 90° is provided (similar to the first embodiment), from which a large pivoting range in all directions is possible.

[0095] Fig. 4 shows a perspective view of a connector 1 according to a third exemplary embodiment. Both elements 6, 7 each have a blind hole 10, although the blind hole 10 of the second element 7 is not visible. The blind hole 10 of the second element 7 extends along the central axis defined by the union nut 18 (see Fig. 2). In the basic position shown, the blind hole 10 of the first element 6 extends parallel to the central axis. With this connector 1, a basic position of 180° is provided for the two rods concerned, from which a large pivoting range in all directions is possible.

[0096] Fig. 5 shows a perspective view of a connector 1 according to a fourth embodiment. Both elements 6, 7 each have a through-hole 8. An imaginary central axis of the through-hole 8 of the second element 7 intersects the central axis defined by the union nut 18 (see Fig. 2) at right angles. This connector 1 provides a basic position of 0° for the two rods involved, from which a large pivoting range in all directions is possible.

[0097] Fig. 6 shows a perspective view of a connector 1 according to a fifth embodiment with two series-connected ball joints 12. For this purpose, each element 6, 7 has a neck 26 and a ball portion 14 formed thereon (see Fig. 2). The two corresponding ball receptacles 16 (see Fig. 2) are formed in a sleeve part 31, onto which the two union nuts 18 are screwed in opposite directions.

[0098] The connector 1 is shown in Fig. 6 in its basic position, in which the two elements 6, 7 are arranged relative to one another in such a way that the necks 26 of the two elements 6, 7 extend along the central axis 24 of the two union nuts 18.

[0099] With regard to the configuration of the holes 8, 10, the fifth embodiment corresponds to that of the first embodiment shown in Figures 1 and 2.

[0100] Fig. 7 shows a sectional view of a variant of the ball joint 12 of the connectors 1 of the preceding figures. The ball section 14 is clamped against a circumferential conical inner wall 33 of the ball receptacle 16 by means of the clamping collar 20 of the union nut 18, which forms an annular contact with the ball section 14. The conical inner wall 33 is aligned concentrically to the central axis 24 of the union nut 18 and has an annular contact with the ball section 14, wherein the annular contact is concentric to the central axis 24. The ball receptacle 16 with the conical inner wall 33 is formed integrally with the second element 7.

[0101] Disclosed are a spinal stabilization system and a connector 1 therefor. The connector 1 comprises two elements 6, 7, each having a receptacle with a fastening device for a rod 4, 5 of the spinal stabilization system. The receptacles are, for example, holes 8, 10. The fastening devices are, for example, clamping screws 28. The two elements 6, 7 are coupled to one another or to one another or to one another by means of a ball joint 12 or by means of several ball joints 12. The at least one ball joint 12 comprises a (respective) blocking device with a union nut 18. Fig. 8 is a perspective view and Fig. 9 a sectional view of an arrangement with two rods 4, 5 and a connector 1 according to a sixth exemplary embodiment. Each rod 4, 5 is accommodated in an element 6, 7 and clamped therein by means of a grub screw 28, 30 which can be countersunk into the element 6, 7.The second rod 5 is accommodated in a blind hole 10, while the first rod 4 is accommodated in a jaw-like clamp. The first grub screw 28 is countersunk into one of the two claws 6a of the clamp of the first element 6.

[0102] The arrangement shown serves to stably connect a sacral implant screw and a pedicle screw screwed into a lower vertebra (both not shown) by clamping these two implant screws to the free end sections of the rods 4, 5.

[0103] The two affected rods 4, 5 can, with the grub screws 28, 30 loosened, initially be varied in their relative position to one another by moving them in the receptacles relative to the elements 6, 7 and together with the elements 6, 7 which can be pivoted relative to one another, and then secured in a desired position, i.e. locked against further movement, simply by tightening the two grub screws 28, 30.

[0104] Fig. 9 shows that the first element 6 has a first central axis 24 extending transversely to the first rod 4, along which a circular-cylindrical through-hole is provided. A circular-cylindrical insert 32, designed as a bushing, is inserted into the through-hole and is displaceable along the first central axis 24. The insert 32 forms a circumferential contact with the outer surface of the first rod 4, on the one hand, and with a ball portion 14 of a ball joint 12 fastened to the second element 7, on the other hand.

[0105] When the first grub screw 28 is screwed into the clamping position shown in Figures 8 and 9, the grub screw 28 (in a linked clamping sequence) clamps the first rod 4 (transverse to its direction of extension) against the insert part 32 and further clamps the insert part 32 against the spherical section 14. This clamps the first rod 4 in the first element 6 and further clamps the spherical section 14 in the first element 6. The second clamping fixes the two elements 6, 7 in position relative to one another.

[0106] The screw axis 29 of the first grub screw 28 shown in Fig. 9 and its screw bore have an angle of approximately 90° to the first central axis 24 in the sixth embodiment according to Figs. 8 and 9. In order to nevertheless generate a force component on the first rod 4 in the direction of the insert part 32, the grub screw 28 must engage off-center on the rod 4 and / or the grub screw 28 has a front-end contact cap (or a contact cone) that engages off-center on the rod 4. In the embodiment shown, both features are present.

[0107] Fig. 10 is a sectional, enlarged view of a section of the sixth embodiment of the connector 1 from Fig. 9. It particularly shows the ball joint 12. The ball section 14 is formed integrally with a neck 26, a contact collar 36, and a pin. The one-piece component formed from the aforementioned components is screwed and secured into a blind hole of the second element 7 by a thread 34 of the pin, with the contact collar 36 resting against the second element 7.

[0108] The ball joint 12 is further formed by a clamping collar 20 of the first element 6 engaging behind the ball portion 14 and having an annular contact with the ball portion 14. Along the first central axis 24 of the first element 6, adjacent to the clamping collar 20, a ball receptacle 16 is formed inside the first element 6 by a radial widening. The ball receptacle 16 is arranged between the clamping collar 20 and the through-hole for the insert part 32. The insert part further forms a clamping collar 23 for contact with the ball portion 14 in order to engage with it and clamp it.

[0109] In order for the connector 1 to be mounted in which the component can be pushed through the through-hole of the first element 6, the following size ratios apply in particular: the outer diameter a of the contact collar 36 is less than the inner diameter b of the clamping collar 20 is smaller than the outer diameter c of the spherical section 14 is smaller than the inner diameter d of the through-hole for the insert part 32.

[0110] Fig. 11 is a sectional view of an arrangement with two rods 4, 5 and a connector 1 according to a seventh embodiment. The seventh embodiment corresponds to the sixth embodiment of the preceding figures except for the arrangement of the screw axis 29, i.e., the first grub screw 28 and its screw bore. Consequently, the shape of the corresponding claw 6a of the first element 6 also differs from that of the sixth embodiment.

[0111] In the seventh embodiment, the screw axis 29 of the first grub screw 28 and its screw bore have an exemplary angle of approximately 125° to the central axis 24 of the first element 6. This improves the force application angle of the grub screw 28.

[0112] During the production of the first element 6 of the seventh embodiment, the screw hole with a vertical screw axis 29 can first be machined in the claw 6a. After the component with the ball portion 14 is passed through the through-hole and the insert part 32 is inserted into the through-hole, the claw 6a is bent. The first element 6 is then hardened.

[0113] The position of the two elements 6, 7 shown in Figures 8 to 11 deviates from the so-called home position. In the home position, the first central axis 24 would coincide with the second central axis 38 (shown only in Figure 10). Starting from this home position, the ball joint 12 can be pivoted equally far in all directions, e.g., at least 20° or at least 25°. List of reference symbols:

[0114] 1 connector device

[0115] 2 Tulip / receiving sleeve (of a first implant screw)

[0116] 3 Tulip / receiving sleeve (of a second implant screw)

[0117] 4 first staff

[0118] 5 second staff

[0119] 6 first element / first rod housing

[0120] 6a Claw

[0121] 7 second element / second rod housing

[0122] 8 through holes

[0123] 10 blind hole

[0124] 12 3D swivel joint / ball joint

[0125] 14 3D swivel head section / ball section

[0126] 16 3D swivel head mount / ball mount

[0127] 18 Screw element / union nut

[0128] 20 clamping collar (of the first element / screw component)

[0129] 22 inner wall

[0130] 23 Clamping collar (of the insert part)

[0131] 24 (first) central axis

[0132] 26 Neck

[0133] 28 first clamping screw / first internal rod fixation

[0134] 29 screw axle

[0135] 30 second clamping screw / second internal rod fixation

[0136] 31 Sleeve part

[0137] 32 insert part

[0138] 33 conical inner wall

[0139] 34 threads

[0140] 36 contact collar a, b, c, d diameter

Claims

Claims 1 . A connector device (1) intended and designed to couple at least two rods (4, 5) of a spinal stabilization system in a selected or selectable relative position and / or relative orientation, for which the connector device (1) has at least the following components: - a first rod receiving housing (6) which forms or has a first receiving shaft for receiving a first rod (4) and has a first internal rod fixing (28), preferably in the form of a clamping screw, clamping collar or clamp, - a second rod receiving housing (7) which forms or has a second receiving shaft for receiving a second rod (5) and has a second internal rod fixing (30), preferably in the form of a clamping screw, clamping collar or clamp, which is formed separately from the first rod fixing (28) and can be actuated independently thereof, and - a preferably lockable articulated coupling (12) which couples the first and second rod receiving housings (6, 7) to one another and is provided and designed to permit an articulated rotary movement about three mutually perpendicular axes.

2. Connector device (1) according to claim 1, characterized in that the articulated coupling (12) has a joint head section (14) and a joint head receptacle (16) in which the joint head section (14) is held, and that the joint head receptacle (16) can be narrowed in order to clamp the joint head section (14) in the joint head receptacle (16).

3. Connector device (1) according to claim 2, characterized in that the joint head receptacle (16) has a screw element, in particular a union nut (18), which can be screwed into or onto the joint head receptacle (16) or onto the joint head receptacle (16) in order to narrow the joint head receptacle (16) directly or indirectly and to clamp the joint head section (14).

4. Connector device (1) according to claim 2 or 3, characterized in that the joint head section (14) is fastened to the first rod receiving housing (6) via a neck (26), in particular via a thread formed on the neck (26), or is connected thereto in one piece, in particular by welding, wherein the neck (26) is preferably encompassed by a clamping collar (20) of the screw element designed as the union nut (18).

5. Connector device (1) according to claim 3 or 4, characterized in that the joint head section (14) has a thread on its radial outer surface, via which the union nut (18) can be screwed onto the joint head section (14).

6. Connector device (1) according to one of claims 2 to 5, characterized in that the joint head receptacle (16) has an inner wall (22), in particular a receptacle base wall, or a circumferential conical inner wall (33), against which the joint head section (14) can be clamped by means of the screw element, preferably the union nut (18).

7. Connector device (1) according to claim 2, characterized in that - the joint head receptacle (16) is formed in the first rod receptacle housing (6) and is connected to the first receptacle shaft for the first rod (4), and - an insert part (32), in particular in the form of a sleeve or bolt, is inserted into the first rod receiving housing (6) so as to be movable along a first central axis (24) in such a way that one end of the insert part (32) is arranged in or on the joint head receptacle (16) in order to contact the joint head (14) directly or indirectly, and another end of the insert part (32) adjoins or projects into the first receiving shaft in such a way that the insert part (32) can be clamped directly or indirectly against the joint head (14) via the first rod (4), preferably by means of the first rod fixing means (28), in particular a first clamping screw (28), in order to block the latter.

8. Connector device (1) according to claim 7, characterized in that the first rod fixation (28) has the first clamping screw and a screwing direction and / or a screw hole of the first clamping screw (28) is arranged perpendicular to the first central axis (24).

9. Connector device (1) according to claim 7, characterized in that a screw direction and / or a screw hole of the first clamping screw (28) is set at an angle of more than 90°, preferably between 100° and 140°, more preferably between 120° and 130°, to the first central axis (24).

10. Connector device (1) according to one of the preceding claims, characterized in that at least one of the first and second rod receiving housings (6, 7) for receiving the respective first or second rod (4, 5) - a through hole (8) which runs in particular obliquely or transversely to a joint axis between the first and second rod receiving housings (6, 7), or - has a blind hole (10) which runs in particular parallel to the joint axis or extends towards the joint coupling (12).

11. Connector device (1) according to one of the preceding claims, characterized in that at least the first receiving shaft is designed as a clamp in the first rod receiving housing (6), or that the first rod receiving housing (6) is formed by a clamp.

12. Spinal stabilization system with a connector device (1) according to one of the preceding claims and with a first rod (4) which is inserted or can be inserted into the first rod receiving housing (6), and a second rod (5) which is inserted or can be inserted into the second rod receiving housing (7), preferably furthermore with a first implant screw and a second implant screw, which have a screw head section each with a tulip or receiving sleeve (2) for receiving and fastening the first or second rod (4, 5).

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