Flexible spinal-column connector and spinal-column stabilisation system

Abstract

The invention relates to a flexible spinal-column connector (1) which is designed to connect at least two rods (A, B) of a spinal-column stabilisation system (100) in an adjustable relative alignment, in particular relative position, comprising a rigid connector housing (2) which has at least one first rod-receiving shaft (4) and a second rod-receiving shaft (6), wherein the first rod-receiving shaft (4) is designed to receive a first rod (A) and comprises a first rod fixing element (8), preferably in the form of an adjusting screw (10), a locking clamp, or a clamp, for fixing the received first rod (A), and an alignment element (12) is inserted in the second rod receiving shaft (6), which alignment element has a rod-guiding opening (14) in which the second rod (B) can be received, and, in an alignment state, the alignment element (12) allows adjustment of the alignment of the rod-guiding opening (14) relative to the connector housing (2) and can be shifted into a locked state by a locking element (16) and locks the alignment.

Description

[0001] Flexible spinal connector and spinal stabilization system

[0002] Description

[0003] Technical area

[0004] The present disclosure relates to a surgical flexible spinal connector for connecting at least two rods, such as implant rods, in the field of spinal surgery. Furthermore, the disclosure relates to a spinal stabilization system according to the preamble of the independent claim.

[0005] Technical background

[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 to expand an existing (spinal) construct in the event of revision surgery, 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. The implant screws are anchored by a surgeon in the vertebra or another bone.The implant screws (pedicle screws) have an axial external threaded 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.

[0008] 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 or angled 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.

[0009] State of the art

[0010] Various (spinal) connectors for connecting two rods are known. The two rods can initially be moved and pivoted relative to each other and then secured to each other. Such connectors are called flexible connectors. They are used in particular 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.

[0011] US 8,430,916 B1 discloses a flexible (spinal) connector with a flexible main body which is designed to accommodate both affected rods. A ball joint is provided between the first rod and the main body, whilst the second rod is held directly in a clamp or clip formed integrally in the main body. All components, i.e. the first rod with the ball joint to the main body and the second rod in the clamp or clip of the main body, are fastened by means of a single central screw. In a basic position of the flexible connector, in which the ball joint is not pivoted, the two rods are parallel to one another, whereby the first rod can be pivoted from this basic position within the limits of the ball joint. The disadvantage of this connector is that it (or...whose connector housing) must be slotted as a whole and thus be flexible and not rigid in order for the ball to be able to be inserted at all. Therefore, no closed or rigid version of the connector is possible, which severely limits production, design and safety.

[0012] A connector is also known in the prior art that allows rods to be accommodated at a predefined angular offset from one another. Although the connector is rigid, the open version of the connector has the disadvantage that it has significantly reduced mechanical stability and, in addition, the angular position is fixed (and thus also the relative alignment of the rods to one another), making it not a flexible spinal connector.

[0013] Another connector variant uses a so-called offset connector with a pivoting arm. The disadvantage of this design is that the arm can only pivot in one plane, thus providing only a limited number of degrees of freedom. Especially in complex spinal stabilization systems that are to be supplemented with the flexible connector, a limited-plane alignment (with an aligned rod) reaches its limits and is usually not even possible.

[0014] There are also flexibly adjustable connectors with clampable gearing, in which two bodies, each with a rod holder, can be rotated relative to each other and locked in place by means of the gearing. The disadvantage of this is that only stepwise adjustment is possible, and the rods can only be accommodated in a parallel plane. There are also flexibly adjustable connectors, but these can only accommodate (at least) two rods in a parallel plane, thus limiting the degrees of freedom of alignment.

[0015] Summary of the present disclosure

[0016] It is therefore the object of the present disclosure to avoid or at least mitigate the disadvantages of the prior art and to provide a (spinal) connector for rods and a spinal stabilization system that allows for flexible adjustment of at least two receivable rods, safe handling, and a secure connection of the rods. A partial object can be seen in particular in a design with improved mechanical stability and simpler and more cost-effective production.

[0017] This object is achieved with regard to a spinal connector by the features of claim 1 and with regard to a spinal stabilization system by the features of claim 14.

[0018] A fundamental idea of ​​the present disclosure is to provide a spinal connector with an alignment element, in particular as a ball joint, with which it is possible to flexibly accommodate, align, and ultimately lock an (implant) rod in position. By locking the alignment element, the orientation of the inserted rod can be fixed in any angular position (within the geometric boundary conditions). Thus, in a sense, a flexible connection mechanism for a spinal rod connector is provided, which can be used with any connector to enable even more flexible rod insertion while still being able to fix the rod in the selected orientation (and also its position relative to the connector).

[0019] In other words, according to the present disclosure, a flexible connector, in particular a spinal connector, is provided which is adapted to connect at least two rods of a spinal stabilization system in an adjustable relative orientation, in particular an adjustable relative orientation and relative position (i.e., an adjustable relative position). The connector has a rigidly designed connector housing / connector body which has at least one first rod receiving shaft and a second rod

[0020] Receiving shaft, wherein the first rod receiving shaft is adapted to receive a first rod and has a first rod fixing element, preferably in the form of a clamping screw, a clamping collar or a clamp, for fixing the received first rod, and in the second rod receiving shaft a (separately manufactured) alignment element is inserted, which

[0021] Rod guide opening (along its longitudinal axis) into which the second rod can be received, and the alignment element in a (first) alignment state allows an adjustment of an alignment / orientation of the rod guide opening relative to the connector housing (and thus of the received second rod relative to the connector housing and thus to the first received rod) and can be placed into a (second) locking state by means of a locking element (separate from the fixing element) (which in particular acts directly on the alignment element and is preferably actuable separately from the fixing element) and locks the (currently set) alignment / orientation in order to determine the relative alignment, in particular relative position, of the first rod to the second rod.If, using the inserted alignment element, an alignment can be adjusted around all three axes in the connector (without relative translational movement of the alignment element relative to the connector housing), a surgeon can connect it to a rod of a spinal stabilization system even more flexibly. In particular, a ball-and-socket joint allows free rotation around three axes due to the symmetrical design of its surface (the alignment element as a joint head). The locking element can be used to selectively lock the appropriate alignment of the rod and, in particular, to fix the second rod in the alignment element to determine the relative alignment of the two rods. The alignment element is thus accommodated and mounted in the connector housing in such a way that this allows the alignment to be adjusted.If a rod is inserted, it can be held at various angles and locked in the respective orientation. This offers more flexibility than the classic connector version, where the rod must be inserted into the rigid hole.

[0022] In particular, the spinal connector can be designed with a "closed" connector housing, in which the rod protrudes through a circumferentially closed or rimmed opening and can then be secured as needed. This increases mechanical stability and thus secure fixation, contributing to treatment success and patient health.

[0023] Relative alignment or relative orientation refers to the angular or rotational orientation of the rods relative to each other. Relativity refers to both the relative position and the relative orientation to each other.

[0024] Advantageous embodiments are claimed in the subclaims and are explained in particular below

[0025] According to one embodiment, the alignment element in the second rod receiving shaft can form a ball joint, wherein in particular the degrees of freedom of the ball joint are locked in the locked state by means of the locking element. A ball joint allows both rotation about the longitudinal axis and adjustment of an angle of the longitudinal axis of the rod guide opening (and of the received rod) relative to a longitudinal axis of the rod receiving shaft. For this purpose, the alignment element has a spherical shape as a joint head and is held by a joint socket or ball socket, so that three-axis rotation is possible. This allows particularly simple and flexible alignment of the rod in the rod guide opening.

[0026] In particular, the alignment element can have a spherically shaped radially outer surface structure, preferably with a spherically shaped surface structure extending around the longitudinal axis of the rod guide opening of the alignment element, in particular in the form of a sphere with a cylindrical through-opening in the longitudinal direction as a rod guide opening for adjusting the alignment. The spherical surface (as a spherical head) allows the alignment element to be mounted in an (at least partially section-shaped) spherical inner surface (ball socket).

[0027] According to a further preferred embodiment, the alignment element can be designed such that its outer radius (and circumference against an inner prestressing force) can be elastically reduced radially inwardly by means of the action of force without a rod being accommodated, in particular in front view (seen in the longitudinal axis direction of the rod guide opening) is designed in the form of a cut C-ring or has a through gap / continuous cutout in the longitudinal direction which extends radially outwards from the longitudinal axis in order to generate the C-shaped configuration for radial elasticity.

[0028] Preferably, the alignment element, viewed in the longitudinal direction from the front, can have an accordion-shaped, meander-shaped, or snake-shaped structure around the longitudinal axis, in which a radially outer section is alternately connected to a radially inner section in order to increase structural elasticity or flexibility, wherein in particular a gap is provided between exactly one radially outer section and an adjacent radially outer section instead of a connection to a radially inner section in order to generate an egg-shaped configuration. It can also be said that a spherical body is alternately slotted in the longitudinal direction, namely alternately radially outward and radially inward in order to produce the structure. Alternatively, only the radial outer surface or only the radial inner surface of the spherical body can be slotted in the longitudinal direction.In particular, the spherical (main) body has a slot / gap extending radially outward from its longitudinal axis, which extends along the entire longitudinal axis, i.e. is continuous in the longitudinal axis direction, in order to structurally exhibit radial elasticity.

[0029] Preferably, the alignment element can be designed in the shape of a sphere, which has a central, circular through-opening in the longitudinal direction as a rod guide opening, a (continuous) cut in the longitudinal direction for forming a C-shape, and circumferentially, in particular evenly distributed, radially outer through-grooves (which can also be referred to as slots that extend from the radial outside to the radial inside in sections) in the longitudinal direction. In this embodiment, the slotted sphere can therefore be slotted only on the outside, instead of alternating between the inside and outside.

[0030] According to a further embodiment, the alignment element can have an anti-twist device in the form of a stop, which (when a maximum angle of the adjustable alignment is exceeded) abuts the connector housing, in particular the second rod receiving shaft (on its inner wall), and limits an angle of an adjustable alignment. In particular, the alignment element has a collar, in particular with a cylindrical outer contour or a hollow cylindrical base structure, around the longitudinal axis in an end section viewed in the longitudinal axis direction of the rod guide opening, and the collar forms the anti-twist device and abuts the connector housing. It should be noted that the collar does not have to be annular and closed by 360°, but preferably has at least one cutout aligned with the gap of the spherical base structure of the alignment element.The alignment element can therefore have an anti-twist feature so that the rod can always be inserted (and, to a certain extent, the rod opening always remains similar to the longitudinal axis of the second rod receptacle or bore direction). The spherical alignment element therefore has, in particular, a collar that prevents the spherical alignment element from completely twisting. In particular, a collar can be provided on each side of the alignment element (i.e., on two opposite sides in the longitudinal axis direction of the rod guide opening).

[0031] Preferably, the locking element can have a spherically designed inner surface / spherical inner surface (as a ball socket) for locking, in particular in the form of a screw, in particular a grub screw, with a front-side spherical inner surface that can be screwed in and out of an internal thread in the connector housing, and the spherical inner surface, in the locked state, acts (positively) on the radially outer surface structure of the alignment element in order to lock the alignment. Due to this design, the alignment element with a (convex) spherical surface can be held and guided directly in the (concave) spherical inner surface, wherein the alignment element is placed in a locked state by further screwing in the screw.This allows for a particularly simple but effective design, since the rod receiving shaft does not require any special design, but can, for example, be designed as a circular through-opening. For assembly, the alignment element can be inserted from the outside to the inside in the longitudinal axis and can finally be held by screwing in the screw with a spherical inner surface and locked when screwed in further.

[0032] In particular, the locking element together with the alignment element can form the ball joint.

[0033] In particular, the spinal connector features a longitudinally continuous, multi-slotted ball with a central rod guide opening as an alignment element, which can be clamped by a grub screw with a spherical inner surface as a locking element. By clamping the spherical alignment element, into which the rod / implant rod is or can be inserted, the alignment of the rod can be fixed at any angular position.

[0034] The connector has a spherical inner surface into which the alignment element, such as a multi-slotted ball, can be inserted. The grub screw allows the ball to be compressed flatly, allowing a rod to be clamped.

[0035] According to a further embodiment, the flexible spinal connector can be designed symmetrically to a plane (except for a possible thread, since this should be designed as a standard thread in order to ensure cost-effective and standardized production.

[0036] In particular, the spinal connector can be designed to have two ball joints, in particular two sides or sections of the connector can have a ball joint, thus providing even more flexibility. Thus, a connector can be designed with two ball joints, each allowing adjustment of the orientation of the first rod and the second rod to further increase flexibility. Alternatively or additionally, the first rod receiving shaft can be designed identically to the second rod receiving shaft, and the fixing element can be designed as a locking element, so that both the orientation of the received first rod and the orientation of the second received rod can be adjusted.

[0037] In particular, the first rod receiving shaft can have a U-shaped contour when viewed in the longitudinal direction (or a block-like U-shaped structure) or be designed as a groove, so that a first rod can be inserted from an open side (in the case of a U, the upper, open side, in the case of a groove, the “collection side”), and the two opposite flanks (i.e. the two sides of the U orthe groove) have an internal thread (in a region of the open side) into which a clamping screw with an external thread can be screwed as a fixing element for fixing, or the first rod receiving shaft has a U-shaped contour (structure) or is designed as a groove, in particular such that a rod can be inserted from the open side, but at least in the longitudinal direction, and an internal thread passes through a flank (closed side of) the first rod receiving shaft, so that the screwable fixing element acts on the received first rod and fixes it.In particular, the connector can have a "side-loading" or a "top-loading" option, meaning it can be designed so that a rod can be inserted from the top or from the side. In one variant of the connector, the connector housing can have an open side to facilitate rod insertion. Both side-loading and top-loading variants are conceivable here. With top-loading, the connector housing can be designed with a base angle of the rod receiving slot relative to the connector housing.

[0038] In particular, the connector housing can be constructed in one piece, especially made of a single material, and the first rod receiving shaft can be rigid, as can the second rod receiving shaft. For example, the connector housing can be a single machined cast part or made from a single block, such as milled and drilled. This achieves high mechanical stability. In particular, the connector housing can be made of stainless steel.

[0039] In particular, the fixing element can directly contact the received first rod and act directly / immediately on it and / or the locking element, in particular an (alignment) clamping screw or (alignment) clamping clamp or (alignment) clamp, can directly contact the alignment element and act on it.

[0040] In particular, the fixing element can be actuated independently of / separately from the locking element. Thus, the first rod can be fixed independently of the second rod. For example, the first rod can be inserted and fixed first, and then the second rod can be inserted into the alignment element, aligned, and finally locked in the appropriate position.

[0041] In particular, the flexible spinal connector can be adapted to connect a horizontal rod and a vertical rod of a spinal stabilization system. Preferably, a longitudinal axis of the first rod receiving shaft can intersect a longitudinal axis of the second rod receiving shaft (in particular at a distance from each other) at an angle, preferably at an angle greater than 80°, preferably an angle of 90°. In contrast to other embodiments, the longitudinal axes of the two rod receiving shafts are not (essentially) parallel to each other (possibly with a slight angle of up to 25°, preferably a maximum of 10° of the longitudinal axes relative to each other), but rather a longitudinal axis of the rod receiving shaft is transverse to the other longitudinal axis, in particular perpendicular to it (whereby the longitudinal axes can be spaced apart from each other in space, i.e., they do not have to directly intersect).This provides a spinal connector that allows for an alternative surgical technique for attaching a sacroiliac pedicle screw (via the rod). The spinal connector can accommodate a cross-connecting rod in a flexible angular position (using the alignment element) and be connected to a pedicle screw system or be part of a spinal stabilization system. With this spinal connector (and the corresponding surgical technique), it is possible to connect pedicle screw heads that are not aligned to the spinal stabilization system without having to bend the rod of the spinal stabilization system to the screw head of the sacroiliac screw connection. Such a spinal connector can be used particularly in the lumbosacral spine, where a cross-connecting rod is used in the sacrum.

[0042] In particular, the connector housing can have two bores for the first and second rod receiving shafts, which run essentially perpendicular to each other, preferably with a through-bore for the second rod receiving shaft and a blind bore for the first rod receiving shaft. Alternatively, a through-bore can also be provided for the first rod receiving shaft. Thus, a rod coming from the lumbar region is not inserted at the front of the connector, but the connector housing is adapted so that the rod passes through the connector housing.

[0043] With regard to a spinal stabilization system, the objects are achieved in that it has a spinal connector according to the present disclosure and a first rod which is inserted or receivable into the first rod receiving shaft, and a second rod which is inserted or receivable into the second rod receiving shaft, wherein preferably the second rod has a cylindrical outer contour in the longitudinal direction and a radially outwardly projecting guide wall in the longitudinal direction, which cooperates with a guide groove of the alignment element in order to prevent relative twisting.

[0044] In particular, the spinal connector is adapted to allow a flexible angular position of the rod in the connector of more than 15°, preferably 18°, in any direction, at least for the second rod or the rod guide opening.

[0045] In particular, the first rod receiving shaft can be designed as a through hole or blind bore, which runs in particular parallel to the second rod receiving shaft. In particular, the joint head receptacle for the alignment element can be formed in the second rod receiving shaft and / or by the locking element.

[0046] In particular, an insert part, preferably in the form of a sleeve or bolt, can be inserted into the connector housing as a locking element so as to be movable along a central axis, such that one end of the locking element is arranged in or on the joint head receptacle in order to contact the alignment element (as a joint head) directly or indirectly and (by means of the second rod receiving shaft as a counteraction) can be clamped directly or indirectly against the alignment element (as a joint head) in order to block it.

[0047] In particular, the spinal stabilization system can be adapted to connect a horizontal cross-connection rod and a vertical rod to one another, in particular by means of a correspondingly designed spinal connector according to the present disclosure.

[0048] Short description of the characters

[0049] The present invention will be explained in more detail below using preferred embodiments with reference to the accompanying figures. They show:

[0050] Fig. 1 is a perspective view of a flexible spinal connector according to a first preferred embodiment and an enlarged view of an alignment element and a locking element in the form of a clamping screw;

[0051] Fig. 2 is a cross-sectional view through the spinal connector of Fig. 1;

[0052] Fig. 3 is a perspective view of a spinal stabilization system according to a preferred embodiment, comprising a spinal connector from Figs. 1 and 2 and two rods; Fig. 4 is a perspective view of the spinal stabilization system from Fig. 3, wherein the second rod received in the alignment element has a different orientation than in Fig. 3;

[0053] Fig. 5 is a cross-sectional view of another embodiment of a flexible spinal connector having two alignment elements;

[0054] Fig. 6 is a perspective view of another embodiment of a flexible spinal connector with a side-loading function for the first rod;

[0055] Fig 7 is a perspective view of another embodiment of a flexible spinal connector with a top loading function for the first rod;

[0056] Fig. 8 is a perspective view of an alignment element of a spinal connector according to another preferred embodiment;

[0057] Fig. 9 is a perspective view of an alignment element of a spinal connector according to another preferred embodiment;

[0058] Fig. 10 is a perspective view of a flexible spinal connector according to another embodiment, in which the first rod receiving shaft is aligned at an angle of 90° to the second rod receiving shaft,

[0059] Fig. 11 is a perspective view of a flexible spinal connector according to another embodiment, in which the first rod receiving slot is oriented at an angle of 90° to the second rod receiving slot and provides a top-loading function,

[0060] Fig. 12 is a perspective view of a flexible spinal connector according to another embodiment, in which the rigid connector housing has an arcuate structure; Fig. 13 is a perspective view of a flexible spinal connector according to another embodiment, which, unlike the one in Fig. 12, has two ball joints;

[0061] Fig. 14 is a perspective view of a flexible spinal connector according to another embodiment, in which the first rod is already received and fixed;

[0062] Fig. 15 is a front view of a spinal stabilization system according to a preferred embodiment, in which two flexible spinal connectors according to a preferred embodiment are used;

[0063] Fig. 16 is a perspective view of a flexible spinal connector according to another embodiment, in which the first rod receiving slot is oriented at an angle of 90° to the second rod receiving slot and with an angled connector housing;

[0064] Fig. 17 is a perspective view of a spinal stabilization system with the flexible spinal connector of Fig. 16 and a first and second rod inserted;

[0065] Fig. 18 is a perspective view of a flexible spinal connector according to another embodiment with an arcuate connector housing in which the first rod receiving shaft is angled to the second rod receiving shaft without intersecting it;

[0066] Fig. 19 is a perspective view of an exemplary flexible spinal connector in which at least the part of the connector housing of the first rod receiving shaft is rigid;

[0067] Fig. 20 is a perspective view of an exemplary flexible spinal connector in which the part of the connector housing of the first rod receiving shaft is rigidly formed with a top-loading function; Fig. 21 is a perspective view of a flexible spinal connector according to another preferred embodiment with two ball joints; and

[0068] Fig. 22 is a perspective view of a flexible spinal connector according to another preferred embodiment with only one ball joint.

[0069] The figures are schematic in nature and are intended only to assist in understanding the invention. Identical elements are designated by the same reference numerals. The features of the various embodiments may be interchanged.

[0070] Detailed description of preferred embodiments

[0071] Figures 1 to 4 show a flexible spinal connector 1 (hereinafter referred to as connector) according to a first preferred embodiment, which is adapted to connect exactly two rods A, B of a spinal stabilization system 100 shown in Figures 3 and 4 in at least one adjustable relative orientation to each other.

[0072] Figure 1 shows a perspective view of the connector 1, which comprises a one-piece, rigid, block-shaped connector housing 2, which has a first rod-receiving slot 4 and a second rod-receiving slot 6 located next to one another. The first rod-receiving slot 4 is designed in the form of a channel-shaped through-opening or through-bore and has a circular cross-sectional contour for receiving the first rod A (see also Fig. 3). The cylindrical rod A can be inserted in the longitudinal direction of the through-opening and fixed by means of a first rod-fixing element 8 in the form of a clamping screw 10, which is screwed into an internal through-thread in the connector housing 2, so that its position does not change (the orientation relative to the connector housing 2 is already determined by the longitudinal axis of the circular through-opening).The axis of the clamping screw 10 is perpendicular to the longitudinal axis of the through-hole (see also the cross-sectional view in Fig. 2). A tip of the clamping screw 10 slides into the through-hole (first rod receiving slot 4) when screwed in. When the first rod A is inserted, it contacts and presses directly onto it, clamping it firmly in its current position. The clamping screw 10 clamps the rod A (positively) and blocks all degrees of freedom, preventing any rotation of the rod A.

[0073] The second rod receiving shaft 6 (hereinafter referred to as the second shaft) is located, so to speak, next to the first rod receiving shaft 4, with its longitudinal axis in this embodiment being arranged parallel to the longitudinal axis of the first rod receiving shaft 4. This second shaft 6 also has a circular contour when viewed in cross-section (see also Fig. 2), with a diameter that is larger than that of the first shaft 4. In a central section of the connector housing 2, the diameter widens slightly in the direction of the longitudinal axis and then returns to its original diameter to form a slightly curved, internally spherical surface in this region. It should be noted that this section with the internally spherical surface does not have to be large or long, but rather, as described in detail below, a small undercut due to the diameter differences is sufficient.

[0074] A separately manufactured, tool-free, spherical alignment element 12 is inserted into this second shaft 6. This alignment element 12 has a central rod guide opening 14 with a circular cross-section, which is adapted to receive a second rod B (see Fig. 1 in combination with Fig. 3). The rod B can be inserted in the longitudinal axis direction of the rod guide opening 14. The alignment element 12 forms a ball joint 18 with the above-described section with the internally spherical surface of the second shaft 6, and the alignment element 12 can freely adjust the alignment / orientation of the rod guide opening (or the longitudinal axis of the rod guide opening and thus the longitudinal axis of the inserted second rod B (see Fig. 3)) in an aligned state and is limited only by the geometric conditions of a stop of the inserted rod B against the connector housing 2.In this way, a relative alignment of the second rod B with respect to the first rod A can be achieved. Once the responsible medical personnel, such as the surgeon, have found the suitable relative alignment between rods A and B, the alignment element 12 with the inserted rod B is placed into a locked state by means of a locking element 16 in the form of a clamping screw, and the alignment is locked. Thus, if the alignment element 12 was still freely movable as the spherical head of a ball joint in the (first) aligned state and it was still possible to adjust the alignment (i.e., adjust the angle and even rotate the rod B around its own longitudinal axis), when screwed in, the locking element 16 (see Fig. 2) contacts the spherical alignment element 12, clamps it in the second shaft 6 and locks it in a (second) locked state, and also indirectly presses on the accommodated second rod B (see Fig.3) and fixes it in the locking element 12. Via the screw-in locking element 12, the (serial) connecting chain “connector housing 2 - alignment element 12 - rod B” is rigidly fixed to one another in the second locking state with a corresponding fixed spatial position and thus also the relative alignment and relative position (i.e. the relative position) of the rod B to the rod A.

[0075] In contrast to the prior art, the present connector 1 allows a simple and flexible adjustment of a relative alignment of rod A to rod B with final secure and stable locking and thus also fixation, since no slotted partially elastic connector housing has to be used, but rather a mechanically stable connector housing 2 and the clamping screw 10 can be actuated independently of the locking element 16.

[0076] The degrees of freedom of the ball joint 18 can be easily and securely locked in the locked state with the locking element 16 and released again when unscrewed. Furthermore, the present connector 1 realizes a simple and cost-effective design. The housing can, for example, be manufactured as a single piece of material and then machined, such as through holes and threads being inserted, and only three additional separate components—namely, the clamping screw 10, the locking element 16, and the alignment element 12—are required to provide a functional connector 2. The special design of the spherical alignment element 12, described below, allows for tool-free assembly and disassembly, as well as optimal locking and fixation.

[0077] In Fig. 1, a right-hand section shows an enlarged view of the alignment element 12 and the locking element 16 in the form of a clamping screw. The alignment element 12 has a spherically shaped radially outer surface structure 20 that extends around the longitudinal axis of the rod guide opening (14) of the alignment element 12 and thus forms, in a sense, a (non-ideally geometric) sphere 22 with a cylindrical through-opening in the longitudinal direction as the rod guide opening 14, with which the alignment can be adjusted.

[0078] The specific design of the alignment element 12 allows its outer radius R to be elastically reduced radially inwards by applying force without the rod being accommodated. If the alignment element 12 is pressed together on two opposite sides, the outer radius R is reduced. For this purpose, the alignment element 12 is designed in the form of a cut C-ring 24 in a front view, i.e. the cross section is C-shaped with a through gap 25 that extends in the longitudinal direction (one can also say that at an axial position of the longitudinal axis the cross section is annular with an inner diameter that is relevant for the rod B, and an outer diameter R that is relevant for the connector housing 2 and the locking element 16), wherein the annular cross section has a gap in the circumferential direction, so that this is not circumferentially closed, but forms a C-shaped structure or shape for radial elasticity.

[0079] As seen in Figs. 1 and 2 in a front view in the longitudinal direction, the alignment element 12 has an accordion-shaped, meander-shaped, or serpentine structure 26 around the longitudinal axis (the radially outer surface is, of course, spherical, but only a front view is considered, in which the circumferential structure is the main focus). Specifically, a radially outer section 28 is alternately connected to a radially inner section 30. The radially outer section guides the spherical alignment element 12 in the connector housing 2, while the radially inner section holds the rod. Alternatively, one can also say that the ball 22 has the rod guide opening 14 and longitudinal grooves are alternately introduced radially inward and radially outward to generate the serpentine, circumferential structure 26. This serpentine, circumferential structure 26 serves to increase structural elasticity.

[0080] In addition, a through gap 25 is provided between exactly one radially outer section 28 and an adjacent radially outer section 28 instead of a connected radially inner section to generate the C-shaped configuration. It can also be said that the serpentine, circumferential structure 26 is interrupted at one point and does not form a closed ring to increase elasticity.

[0081] The screw-in locking element 16 has a spherical inner surface 42 on the front side for locking and, in this embodiment, is designed as a grub screw 44 with a spherical inner surface on the front side. The grub screw can be screwed in and out of an internal thread of the connector housing 2, and in the locked state, the spherical inner surface acts forcefully on the radially outer surface structure of the alignment element to lock the alignment. In an embodiment not shown, a positive locking can also be provided in addition to the force locking to ensure particularly secure locking.

[0082] Figures 3 and 4 show a perspective view of the spinal stabilization system 100 with the second rod B inserted (rod A is not shown inserted to better illustrate the functionality of the alignment element 12). In the aligned state of the connector 1, the rod B can be simply and easily aligned via the ball joint 18 and rotated about its longitudinal axis until an optimal alignment with the corresponding angle setting is found. Figures 3 and 4 show exemplary alignments of the rod B.

[0083] Fig. 5 shows a cross-sectional view of another embodiment of the connector 1 according to the present disclosure. In this embodiment, the flexible connector 1 is formed symmetrically to a plane (as seen in Fig. 5, the vertical plane extending in the longitudinal axis direction of the rod receiving shafts 4 and 6).

[0084] The first rod receiving shaft 4 is designed in the same way as the second rod receiving shaft 6, each with an inserted alignment element 12. The first rod fixing element 8 is designed as a locking element 16, so that both an orientation of the received first rod A (not shown here, but the axis of the rod guide opening naturally determines the orientation of the rod A) and an orientation of the second received rod B (not shown here) can be adjusted.

[0085] Fig. 6 shows a further embodiment of a connector 1, which, in contrast to the preceding embodiments, has a modified first rod receiving shaft 4. Specifically, the connector 1 from Fig. 6 provides a so-called side-loading function, in which the first rod A does not have to be pushed through the through-opening of the first rod receiving shaft 4, but can simply be inserted from the side and fixed by means of the clamping screw 10. In this embodiment, the flexibility of the connector for use in a spinal stabilization system is further increased. The first rod receiving shaft 4 is thus designed as a groove 44 with an opening towards the lateral side, so that the first rod A can be inserted from the open side 46.An internal thread 50 passes through a flank 48 of the groove of the first rod receiving shaft 4, so that the screwable clamping screw 10 presses onto the received first rod A and fixes it.

[0086] Fig. 7 shows a further embodiment of a connector 1 which, in contrast to Fig. 6, does not provide a side-loading function but rather a top-loading function. The first rod receiving shaft 4 is again designed as a groove 44 with a U-shaped contour, wherein the open side 46 is an upper side (as seen in Fig. 7), so that the first rod A can be inserted from the upper open side 46. The two opposing flanks 48 have an internal thread 50 into which the clamping screw 10 with an external thread can be screwed for fixing. Fig. 8 shows a further embodiment of the alignment element 12 according to the present disclosure. In contrast to the previous embodiments of the alignment element, this has circumferentially evenly distributed, radially outer through-grooves 32 which extend in the longitudinal direction (of the rod guide opening 14).This design increases rigidity and is even easier to manufacture.

[0087] Fig. 9 shows a further embodiment of the alignment element 12 according to the present disclosure, which has an anti-twist device 34 in the form of a stop 36, which abuts the connector housing 2 (not shown here, but when inserted into the second rod receiving shaft 6) and thus limits an angle of adjustable alignment. The alignment element 12 has, in an end section, viewed in the longitudinal axis direction of the rod guide opening 14, a collar 38 with a cylindrical outer contour 40 around the longitudinal axis, which forms the anti-twist device 34 and abuts the connector housing 2. One can also say that a hollow cylindrical section has been attached to the end of the spherical alignment element 12, which prevents over-twisting of the alignment element 12, so that the second rod B can be inserted in any possible orientation of the alignment element 12.

[0088] Fig. 10 shows a flexible spinal connector 1 according to a further embodiment. Compared to the previous embodiments, the first rod receiving shaft 4 is rotated by 90° and is designed as a blind bore / blind hole, so that a longitudinal axis of the first rod receiving shaft is no longer parallel, but rather perpendicular to a longitudinal axis of the second rod receiving shaft 6. This makes it possible to provide a variant of a flexible spinal connector 1 that is suitable for spinal stabilization systems that require the insertable rods to be at an angle of approximately 90° to one another. In this embodiment, the longitudinal axis of the first rod receiving shaft 4 does not directly intersect the longitudinal axis of the second rod receiving shaft 6, but rather runs just below it. The longitudinal axes are therefore not entirely in one plane.Spinal Connector 1 thus offers the possibility of performing an alternative surgical technique for attaching a sacroiliac screw. Spinal Connector 1 can thus accommodate a cross-connection rod in a flexible angle.

[0089] In this embodiment, the block-shaped connector housing 2 is not rectangular in a front view, but rather consists of two rectangular sections, which on the one hand comprise the first rod receiving shaft 4 and on the other hand the second rod receiving shaft 6, which are arranged at an angle to one another and rigidly connected (i.e. not 180°, but for example 150° or 140°). It can also be said that one rectangular section is pivoted about a longitudinal axis of the second rod receiving shaft 6 by an angle (in particular less than 45° or greater than 180° - 45° = 135°), so that a V-shape is formed, with the first rectangular section on one leg and the second rectangular section on the other leg of the V.

[0090] Furthermore, the connector housing 2 has an opening with a longitudinal axis parallel to a longitudinal axis of the thread of the first rod fixing element 8, which is arranged at a distance therefrom.

[0091] Fig. 11 shows a further embodiment of the present disclosure. In contrast to the embodiment of Fig. 10, this one has a top-loading function by means of two opposing flanks, each of which incorporates the internal thread and which accommodate the first rod fixing element 8 in the form of the clamping screw (grub screw).

[0092] Fig. 12 shows a further embodiment of a flexible spinal connector 1. In this embodiment, the rod is not inserted at the end of the connector housing 2, as depicted in Fig. 10 (and 11) above, but rather the connector housing 2 is curved or has an angle between two rectangular (block) sections, and the first rod receiving shaft 4 is designed in the form of a through-bore from one (so-to-speak lower) side of the connector housing 2 to one (so-to-speak upper) side. As a result, the first rod A, when inserted (not shown here), protrudes through the connector housing 2 and again runs at an angle to an inserted second rod B (not shown).

[0093] Fig. 13 shows a further embodiment of a flexible spinal connector 1, which, in contrast to the one in Fig. 12 with two alignment elements 12, has two ball joints 18. This allows for even better adjustment of the relative alignment, since both the orientation of the first rod A (to the connector housing 2) and the orientation of the second rod B are adjustable.

[0094] Figure 14 shows another embodiment of a flexible spinal connector 1 with an inserted rod A, which is secured by a first rod fixing element, approximately on the rear side (not shown here), and protrudes laterally in a straight line. The orientation of an insertable first rod (not shown here) can be adjusted via the alignment element 12. This shape is particularly compact and allows two rods to be connected to each other at a right angle.

[0095] Fig. 15 shows a spinal stabilization system 100 according to a preferred embodiment with two flexible spinal connectors 1 of the embodiment from Fig. 11 with a top-loading function. The alignment elements 12 allow the received rods to be aligned particularly well with one another. The spinal stabilization system 100 is adapted by means of the two spinal connectors 1 for a sacroiliac connection of a pedicle screw system. The two connectors 1 are connected to one another via a horizontal cross-connecting rod (as the second rod B). In turn, a vertical rod (as the first rod A) is attached to each connector 1, each of which is firmly connected to a plurality of pedicle screws. The design of the connector 1 allows a vertical and horizontal rod to be accommodated.

[0096] Fig. 16 shows a spinal connector 1 according to a further embodiment, in which the spherical alignment element 12 has a through-gap and is slotted alternately at the front and back to create a certain elasticity and again forms the ball joint with the connector housing 2. In Fig. 16, the alignment element is shown again in an enlarged form without being inserted in order to better illustrate the structure. The arrow indicates that the alignment element 12 can be inserted into the connector housing 2 without tools. The alignment element 12 can be pressed together by means of the through-gap and the slots so that the outer radius is reduced, and then inserted into the second rod receiving shaft 6, in which it then (partially) relaxes again after being released against the prestressing force and, in this embodiment, rests (lightly) against the inner wall of the connector housing 2. A spherical inner surface orThe spherical inner surface of the locking element 16 forms the ball joint 18 with the alignment element 12 and holds it in its position in the first alignment state, whereby alignment is still possible, and when the locking element 16 is screwed in further, it clamps the alignment element 12 and locks the orientation.

[0097] Fig 17 shows the spinal connector 1 with the inserted first rod A and inserted second rod B. The first rod A is inserted vertically into the front side of the connector housing (into the blind hole) while the second rod B passes through the connector housing.

[0098] Fig. 18 shows a further embodiment of the spinal connector 1 in which the first rod receiving shaft 4 is not provided on the front side, but is provided continuously through the connector housing 2 (virtually continuously from bottom to top), while the second rod receiving shaft is designed continuously from front to back. Thus, the first rod A can be received or designed continuously through the connector housing 2. Therefore, a rod coming from the lumbar region cannot be inserted at the front side of the connector, but the connector housing 2 is adapted in such a way that the rod is guided through the connector.

[0099] Figures 19 and 20 show variants in which the first rod receiving shaft is rigid and the first rod fixing element can be actuated independently of the locking element. Here, the connector housing is slotted on the side of the ball joint, and the rod is clamped to the flexible receptacle laterally to the ball (the locking element acts indirectly on the alignment element). In Figure 20, a vertical rod can be inserted via a top-loading function to facilitate rod insertion.

[0100] Fig. 21 shows a further embodiment of a spinal connector 1, which has two through-openings as rod receiving shafts 4 and 6, which do not run parallel to each other, but rather (slightly offset) form a right angle to each other. Each rod receiving shaft 4 and 6 has a locking element 12 and forms a ball joint 18 with it, so that both orientations are adjustable. This allows insertable first and second rods A and B (not shown here) to be aligned at an angle similar to 90° to each other (i.e., crossing each other but spaced or offset).

[0101] Fig. 22 shows a further embodiment of a spinal connector 1, which, in contrast to the embodiment of Fig. 21, has only one alignment element 12, so that only one orientation is adjustable, while the first rod receiving shaft 4 again has a rigid longitudinal axis relative to the connector housing 2. In this embodiment, the flexible insertion of a vertical rod adjacent to the lumbar region is possible.

[0102] List of reference symbols

[0103] 1 Flexible spinal connector

[0104] 2 connector housings

[0105] 4 first rod receiving shaft

[0106] 6 second rod receiving shaft

[0107] 8 first rod fixing element

[0108] 10 clamping screw

[0109] 12 Alignment element

[0110] 14 Rod guide opening

[0111] 16 locking element

[0112] 18 ball joint

[0113] 20 radial outer spherical surface

[0114] 22 bullets

[0115] 24 C-ring

[0116] 25 passage gap

[0117] 26 Meandering structure

[0118] 28 radial outer section

[0119] 30 radial inner section

[0120] 32 through groove

[0121] 34 Anti-twist device

[0122] 36 stop

[0123] 38 collar

[0124] 40 cylindrical outer contour

[0125] 42 spherical inner surface

[0126] 44 gutter

[0127] 46 open page

[0128] 48 flank

[0129] 50 internal threads

[0130] 100 Spinal Stabilization System

[0131] A first bar B second bar

[0132] C Guide wall

[0133] R outer radius

Claims

Claims 1. A flexible spinal connector (1) adapted to connect at least two rods (A, B) of a spinal stabilization system (100) in an adjustable relative orientation, in particular relative position, to one another, comprising a rigid connector housing (2) having at least a first rod receiving shaft (4) and a second rod receiving shaft (6), wherein the first rod receiving shaft (4) is adapted to receive a first rod (A) and has a first rod fixing element (8), preferably in the form of a clamping screw (10), a clamping collar, or a clamp, for fixing the received first rod (A), and an alignment element (12) is inserted into the second rod receiving shaft (6), which alignment element has a rod guide opening (14) into which the second rod (B) can be received,and the alignment element (12) in an alignment state allows adjustment of an alignment of the rod guide opening (14) relative to the connector housing (2) and can be set into a locking state by means of a locking element (16) and locks the alignment., 2. Flexible spinal connector (1) according to claim 1, characterized in that the alignment element (12) forms a ball joint (18) in the second rod receiving shaft (6) and the degrees of freedom of the ball joint (18) are locked in the locked state by means of the locking element (16).

3. Flexible spinal connector (1) according to claim 1 or 2, characterized in that the alignment element (12) has a spherically formed radially outer surface structure (20), preferably with a spherically formed surface structure (20) running around the longitudinal axis of the rod guide opening (14) of the alignment element (12), in particular in the form of a sphere (22) with a circular through opening in the longitudinal direction as a rod guide opening (14) in order to adjust the alignment.

4. Flexible spinal connector (1) according to claim 3, characterized in that the alignment element (12) is designed such that its outer radius (R) can be elastically reduced radially inward by means of the action of force, in particular in front view is designed in the form of a cut C-ring (24) or has a through gap (25) in the longitudinal direction which extends radially outwards from the longitudinal axis in order to generate a C-shaped configuration for radial elasticity.

5. Flexible spinal connector (1) according to claim 3 or 4, characterized in that the alignment element (12) has, viewed in the longitudinal direction, an accordion-shaped or meander-shaped or serpentine-shaped structure (26) around the longitudinal axis, in which a radially outer section (28) is alternately connected to a radially inner section (30) in order to increase structural elasticity or flexibility, wherein in particular a through gap (25) is provided between exactly one radially outer section (28) and an adjacent radially outer section (28) in order to generate a C-shaped configuration.

6. Flexible spinal connector (1) according to one of the preceding claims, characterized in that the alignment element (12) is designed in the form of a sphere (22) which has a central, circular through-opening in the longitudinal direction as a rod guide opening (14), a through-slit (25) or cut in the longitudinal direction which extends radially outwards from the longitudinal axis for forming a C-shaped configuration, and circumferentially, in particular evenly distributed, radially outer through-grooves (32) or slots which extend in the longitudinal direction.

7. Flexible spinal connector (1) according to one of the preceding claims, characterized in that the alignment element (12) has an anti-twist device (34) in the form of a stop (36) which abuts the connector housing (2), in particular the second rod receiving shaft (6), and limits an angle of an adjustable alignment, wherein in particular the alignment element (12) has a collar (38) in an end section seen in the longitudinal axis direction of the rod guide opening (14), in particular with a circular outer contour (40), around the longitudinal axis, which forms the anti-twist device (34) and abuts against the connector housing (2).

8. Flexible spinal connector (1) according to one of the preceding claims, characterized in that the locking element (16) has a spherical inner surface (42) for locking, in particular is designed in the form of a grub screw (44) with a front-side spherical inner surface which can be screwed in and out of an internal thread of the connector housing (2), and the spherical inner surface (42) in the locked state acts on the radially outer surface structure (20) of the alignment element (12), in particular clamps it in a force-fitting manner.

9. Flexible spinal connector (1) according to one of the preceding claims, characterized in that the flexible spinal connector (1) is designed symmetrically to a plane, and / or the first rod receiving shaft (4) is designed the same as the second rod receiving shaft (6), each with an alignment element (12) and the first rod fixing element (8) is designed as a locking element (16), so that both an orientation of the received first rod (A) and an orientation of the second received rod (B) can be adjusted.

10. Flexible spinal connector (1) according to one of the preceding claims, characterized in that the first rod receiving shaft (4) has a U-shaped contour when viewed in the longitudinal direction or is designed as a groove (44), so that the first rod (A) can be inserted from an open side (46), and the two opposite flanks (48) have an internal thread (50) into which a clamping screw with an external thread can be screwed as the first rod fixing element (8) for fixing, or the first rod receiving shaft (4) has a U-shaped contour when viewed in the longitudinal direction or is designed as a groove (44), in particular such that the first rod (A) can be inserted from the open side (46), but at least can be introduced in the longitudinal direction, and a flank (48) of the first rod receiving shaft (4) Internal thread (50) passes through, so that the screwable first rod fixing element (8) acts on the received first rod (A) and fixes it.

11. Flexible spinal connector (1) according to one of the preceding claims, characterized in that the connector housing (2) is designed in one piece, in particular in one piece, and both the first rod receiving shaft (4) and the second first rod receiving shaft (6) are rigid and have a rigid relationship to one another.

12. Flexible spinal connector (1) according to one of the preceding claims, characterized in that the first rod fixing element (8) directly contacts the received first rod (A) and acts on it and the locking element (16) directly contacts the alignment element (12) and acts on it.

13. Flexible spinal connector (1) according to one of the preceding claims, characterized in that the fixing element (8) can be actuated independently of the locking element (16) 14. Spinal stabilization system (100) with a Spinal connector (1) according to one of the preceding claims and a first rod (A) which is inserted or receivable in the first rod receiving shaft (4), and a second rod (B) which is inserted or receivable in the second rod receiving shaft (6), wherein preferably the second rod (B) has a cylindrical outer contour in the longitudinal direction and a radially outwardly projecting guide wall (C) in the longitudinal direction, which cooperates with an inner guide groove of the alignment element (12) in order to prevent relative twisting.

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