INTERVERTEBRAL IMPLANT

Description

[0001] The invention relates to an intervertebral implant with at least two upper and two lower contact bodies with contact surfaces, with an actuator having a threaded body having an axis of extension, which is provided with counter-rotating threads arranged one behind the other, with wedges axially movable on the threaded body, which can be moved along it by rotating the same, and with ramps of at least one ramp body of a wedge engaging at least on opposing surfaces of at least one part of the contact bodies and extending towards each other at a finite angle of less than 90°.

[0002] US Patent 2019 / 0269521 A1 discloses a generic intervertebral implant in which individual contact bodies of the implant can be moved laterally and vertically apart. Lateral separation is achieved by an actuator with a threaded rod featuring opposing threads, via axially displaceable sliding elements equipped with ramps that engage corresponding surfaces of the contact bodies.

[0003] The vertical separation of the contact bodies is achieved indirectly via intermediate bodies arranged between the wedges and the support bodies, which are slidable in sloping grooves of the lower support bodies.

[0004] Such a design is, on the one hand, complex and, on the other hand, prone to malfunctions due to the additional movable intermediate bodies provided in addition to the wedges and the support bodies, as this can cause tilting and jamming.

[0005] The invention is therefore based on the objective of creating an intervertebral implant that is simple in design while avoiding the aforementioned disadvantages and ensures reliable function by enabling staggered movement of the supporting bodies in different directions.

[0006] According to the invention, the aforementioned problem is solved with a generic intervertebral implant, which is characterized in that the wedges are designed as double wedges with two ramp bodies arranged one behind the other in the direction of the extension axis, and that the ramps of one ramp body have different orientations to the ramps of the other ramp body, and that the ramps of the first ramp body attack the contact bodies laterally, while the ramps of the second ramp body attack the contact bodies vertically.

[0007] The invention thus provides for two ramp bodies arranged axially one behind the other with different orientations of the ramps on different ramp bodies on the same double wedge, wherein the first ramp body serves to move the support bodies apart laterally or sideways, the second ramp body serves to move the support bodies apart in a vertical or cephalocaudal direction.

[0008] In particular, it is provided that the ramps of different orientations are arranged on different ramp bodies of a double wedge.

[0009] A highly preferred embodiment of the invention provides that the ramps of first ramp bodies are vertically aligned with the horizontal surface normal, and the surface normals of the ramps of second ramp bodies, in a different orientation, enclose a finite angle other than 90° to the vertical. A further development is provided that the interacting mating surfaces of the contact bodies with ramps of different orientations have a different distance in the extension direction of the axis of the actuator's threaded body compared to the distance between the ramp bodies of different orientations. In particular, it is provided that the distance between ramps of different orientations relative to the distance between the mating surfaces on the contact bodies is such that, upon rotation of the threaded body, the contact bodies are moved at least laterally apart and only subsequently raised relative to each other.

[0010] In concrete terms, this can be achieved by spacing the ramps relative to the opposing surfaces such that the contact bodies first engage the opposing surfaces laterally via the ramps of the first ramp body to move them apart, and only upon further rotation do the ramps of the second ramp body engage the opposing surfaces of the contact bodies to lift them. This effectively creates a staggered movement of the supporting body.

[0011] It can also be provided according to the invention that the distance between the ramps of different orientations of a double wedge with two ramp parts is less than the distance between the associated counter surfaces.

[0012] Further preferred embodiments of the invention provide that the actuator has a radial disk or a radial wheel firmly connected to the threaded body, which engages in slots of the contact bodies directed radially to the axis of the threaded body for the axial guidance of the same and / or by means of guide rods engaging slidably at least in the upper contact bodies for guiding the contact bodies relative to each other.

[0013] The outer contact surface of the upper contact bodies and the lower outer surface of the lower contact bodies are generally not parallel to each other; rather, it is preferably provided that the outer contact surface of the upper contact bodies forms an angle between 5° and 15°, preferably between 9° and 11°, with the outer contact surface of the lower contact bodies in order to achieve a better adaptation to the natural lordosis of the lumbar spine. The proximal area of ​​the contact surfaces of each individual contact body begins with surfaces that rise linearly at half this angle when viewed from the horizontal mid-plane and then transitions into an opposite curvature in the distal area to form a rounded shape that also facilitates insertion into the intervertebral space.

[0014] In a preferred embodiment, the ramp bodies are formed integrally with a double wedge.

[0015] In a highly preferred embodiment, contact bodies positioned one above the other and / or side by side are movably connected to each other via linear guides, wherein at least one linear guide is a tongue-and-groove guide, preferably a dovetail guide. These linear guides direct forces occurring under shear stress through the contact bodies, thus reducing or eliminating stress on internal (functional) structures, such as the displacement mechanism of the double screw.

[0016] Further advantages and features of the invention will become apparent from the claims and from the following description, in which a preferred embodiment of the invention is explained with reference to the drawing. The drawing shows: Fig. 1 An exploded view of a first intervertebral implant according to the invention; Fig. 2 A perspective view of the drive mechanism of the implant according to the invention. Fig. 1 in the compressed state; Fig. 2a a side view of the drive mechanism of the Fig. 2 ; Fig. 3 a perspective view of the drive mechanism of the embodiment of the Fig. 1 in the expanded state; Fig. 3a a side view of the drive mechanism according to the Fig. 3 ; Fig. 4 a perspective view of a double wedge of the implant according to the invention Fig. 1 ; Fig. 4a a top view of the double wedge of the Fig. 4 ; Fig. 4-legged side view of the double wedge of the Fig. 4 Fig. 5 shows the complete implant in the compressed state; Fig. 5a shows the implant in the compressed state with the upper anterior contact body removed; Fig. 6 shows the implant in a first step in a laterally (sideways) expanded state only; Fig. 6a shows the implant in a first step in a laterally (sideways) expanded state only. Fig. 6 with the upper front contact body removed; Fig. 7 the implant according to the invention in the laterally and vertically expanded state after the second expansion step; Fig. 7 the implant according to the invention in the laterally and vertically expanded state after the second expansion step according to Fig. 7 with the upper anterior support body removed; Fig. 8 an exploded view of another embodiment of the intervertebral implant according to the invention; Fig. 9 a perspective view of another double wedge of the embodiment of the Fig. 8 ; Fig. 10 a perspective view of the implant of the Fig. 8 in the compressed state; Fig. 10a a side view of the implant of the Fig. 8 , 10 in the compressed state; Fig. 11 an exploded view of an implant of the Fig. 8 in the fully expanded state; Fig. 11a a side view of the implant of the Fig. 8 in the fully expanded state; and Fig. 12 a modified embodiment of the intervertebral implant according to the invention with linear guides in the compressed state; Fig. 13 the embodiment of the Fig. 12 in a laterally or horizontally expanded state; Fig. 14 a side view of the intervertebral implant according to the invention. Fig. 12 in the area of ​​the upper and lower contact bodies on the right (as seen from the attack side); Fig. 15 a perspective view of the inside of the upper contact body on the left (as seen from the attack side); and Fig. 16 a view from below of adjacent lower contact bodies.

[0017] A first embodiment of the intervertebral implant according to the invention is described in the Fig. 1 bis Fig. 7a The implant 1 has two upper contact bodies 2.1 and 2.2 (2.2 in the Fig. 5a , 6a , 7a removed) and opposite this are two lower contact bodies 2.3, 2.4. Centrally located between these is an actuator or drive mechanism 3 (in particular also Fig. 3, 3a ).

[0018] The contact bodies 2.1-2.4 have upwardly or downwardly directed contact surfaces which in their central area, for example 2.1.1, 2.2.1, 2.3.1, 2.4.1, are essentially horizontally directed or form or define a horizontal area, while the contact surfaces slope down or are bent at their ends in the longitudinal direction, with opposing upper and lower contact surfaces running towards each other.

[0019] The drive mechanism 3 has a central threaded body 4 with an axis A that also determines the longitudinal direction of the implant. The threaded body 4 has two threads 4.1 and 4.2 arranged one behind the other with opposing orientations. Thread 4.1 is the distal thread, and thread 4.2 is the proximal thread. At its proximal end, the threaded body 4 has an engagement contour 4.4 for engaging a tool (not shown) with which the threaded body 4 can be rotated. A guide wheel 4.3 is arranged centrally on the threaded body 4 and is rotationally fixed to it. The guide wheel engages in radially oriented transverse slots 2.5 of the contact bodies 2.1–2.4 and thus determines and fixes the relative axial position of the contact bodies 2.1–2.4 and the threaded body 4 to each other—independent of the lateral and vertical movements of the contact bodies 2.1–2.4 relative to each other.

[0020] Double wedges 5, 5a with two ramp sections, each with internal threads 5.3 adapted to the threads 4.1, 4.2, are mounted on the threaded body 4. These wedges are mirror images of each other and arranged mirror images on both sides of the wheel.

[0021] Each double wedge 5, 5a has a first and a second ramp body 5.1, 5a.1, 5.2, 5a.2, which are arranged one behind the other in the direction of axis A and directed outwards away from wheel 4.3. The ramps 5.1.1 and 5.1.2 of ramp body 5.1 run outwards towards each other from wheel 4 as follows ( Fig. 2 ): The ramp body 5.1 has as its upper and lower ramp surfaces a ramp 5.1.1 and 5.1.2, each of which has a surface normal F5 with a finite angle other than 90° to a vertical V to the axis A ( Fig. 2, 2a The same applies to the other ramps of the ramp structure.

[0022] The contact body 2.1 (and likewise the contact body 2.2) has a counter surface 2.6 facing the ramp 5.1.1 with approximately or exactly the same inclination as the ramps 5.1.1, 5.1.2, against which the ramp 5.1.1 or 5.1.2 acts when, by rotating the threaded body 4, the double wedge 5 and the ramp body 5.1 and thus the ramps 5.1.1, 5.1.2 are moved away from the wheel 4.3 along the axis A outwards (to the left in the illustration).

[0023] The same principles apply to the ramp body 5a.1 and the ramps 5a.1.1 and 5a.1.2 located on it, with the corresponding mating surface 2.1.3 being formed on the inside of the contact body 2.1. The same applies to the corresponding ramps of the contact body 2.2 and to the lower ramp 5a.1.2 and corresponding mating surfaces of the lower contact bodies 2.3 and 2.4.

[0024] The double wedge 5, offset inwards in the axial direction A towards the ramp body 5.1, as mentioned, has the ramp body 5.2 with ramps 5.2.1 and 5.2.2, which are vertically aligned (also Fig. 3 ), also run obliquely towards each other from the wheel 4.3 outwards and each have a surface normal F5.2 which is directed horizontally, i.e. perpendicular to the vertical V, and spans a horizontal plane with the axis A ( Fig. 3 ).

[0025] The ramp 5.2.1 interacts with a vertically oriented, inclined counter surface 2.4.2 on the contact body 2.4 and also with a corresponding counter surface on the front upper contact body 2.3 and, when the double wedge 5 is moved outwards from the wheel 4.3 by turning the threaded body 4, can move the contact body 2.4 (and also the contact body 2.3) outwards until the ramp 5.2.1 disengages from the counter surface 2.4.2 (and the corresponding counter surface of the contact body 2.3), so that subsequently, with further screwing of the threaded body 4, the double wedge 5 can move along the contact body 2.4 and also the contact body 2.3.

[0026] The same applies to ramp 5.2.2 and the corresponding counter surface on contact bodies 2.1 and 2.2, as well as the corresponding ramps 5a.2.1, 5a.2.2 of ramp body 5a.2 on double wedge 5a ( Fig. 3, 3a ), whereby reference is made to the above explanation regarding the interaction of ramp 5.2.1 and the opposite surface 2.4.2.

[0027] In the first version of the Fig. 1-7a The ramp body 5.2 has upper and lower projections 5.2.1.2 extending laterally from it and beyond the ramps 5.2.1 ( Fig. 2 ), so that the latter engages in a slot 2.1.4 of the contact body 2.1 and thus guides it horizontally relative to each other during the lateral separation of the contact bodies due to the contact surfaces of the ramp bodies 5.2. The same applies to the second projections of the ramp bodies 5.2 and 5a.2 and associated slots 2.3.4 of the contact bodies 2.1-2.4.

[0028] The slot 2.1.4 has chamfers towards each other in its area facing the end faces. This ensures guidance when the contact bodies 2.1 and 2.3, or also 2.2 and 2.4, move apart vertically under the influence of the ramp bodies 5.1, 5a.1, as described above.

[0029] The same applies to the projections shown in the drawings in the area of ​​the ramp body 5a.2 and associated slots such as 2.3.4a., for which reference is made to the above description as well as to corresponding projections on the opposite side of the two ramp bodies mentioned and to corresponding slots in the contact bodies 2.1 and 2.2.

[0030] Finally, for example, guide rods 6.1, 6.2 are formed between the contact bodies 2.1 and 2.2, which are slidable in the two contact bodies 2.1, 2.2 and guide the two contact bodies relative to each other during their lateral separation movement and vertical lifting movement.

[0031] Corresponding guide rods are provided in the lower contact bodies 2.3 and 2.4, which also guide these bodies towards each other during the aforementioned lateral and lowering movements.

[0032] The characters, especially the Fig. 1 It can be seen that the axial distance from ramp body 5.2, and thus its ramp 5.2.1, to ramp body 5.1 or its ramp 5.1.1 (and the corresponding non-visible ramps) is less than the axial distance between the counter surface 2.4.2 and the counter surface 2.6, or the corresponding counter surface of the respective contact body. The same applies to the distance between ramp bodies 5a.2 and 5a.1, or their ramps, in relation to the corresponding counter surfaces on the contact bodies.

[0033] This ensures that both the upper contact bodies 2.1 and 2.2 and the lower contact bodies 2.3 and 2.4 are initially moved laterally apart by the ramp bodies 5.2 and 5a.2 or their ramps, and only subsequently, i.e., at a later time interval, are the contact bodies 2.1 and 2.3 as well as the contact bodies 2.2 and 2.4 moved apart vertically by the ramp bodies 5.1 and 5a.1 or the ramps, and thus only in the laterally widened state are the contact bodies 2.1-2.4 moved against the upper and lower vertebral bodies, thereby reducing the risk of damage to them.

[0034] The embodiment of the intervertebral implant according to the invention is described in the Fig. 8 bis 11a This embodiment is shown to have essentially and largely the same design as the first embodiment of the Fig. 1 bis 7a Therefore, identical parts are provided with the same reference numerals, and reference is made to the preceding description of the first embodiment. The essential difference from the slightly different design of the ramp bodies 5.2, 5.2a is the double wedge 5, 5a. The difference lies in the fact that these, instead of the two-sided projections of the corresponding ramp bodies of the embodiment of the Fig. 1 bis 7a The illustrations show lateral projections 5.2.5 and 5.2.6 of ramp body 5.2 and 5a.2.6 on each side (the projection on the other side of ramp body 5a.2 is not shown). Projections 5.2.5, 5.2.6, and 5a.2.6 are located at the midpoint of ramp body 5.2 and 5a.2, respectively. They engage in slots 2.1.5, 2.1.6, 2.2.5, 2.2.6, 2.3.5, 2.3.6, 2.4.5, 2.4.6 which initially run horizontally, then obliquely, with the outer inclined section of slots 2.1.5, 2.1.6, 2.2.5, 2.2.6 of the upper contact bodies 2.1, 2.2 running downwards outwards, while the outer inclined sections of slots 2.3.5, 2.3.6, 2.4.5, 2.4.6 of the lower contact bodies 2.3, 2.4 running upwards outwards.

[0035] This causes the lower contact bodies 2.3 and 2.4 to be pushed downwards and the upper contact bodies 2.1 and 2.2 upwards when the projections 5.2.5 and 5.2.6 (as well as the corresponding projections of the ramp body 5a) enter the inclined sections of the aforementioned slots, thus resulting in vertical spreading. The preceding horizontal spreading of the contact bodies 2.1 and 2.2 relative to each other and 2.3 and 2.4 relative to each other occurs in the same manner as described with reference to the first embodiment.

[0036] In order for approaches 5.2.5 and 5.2.6 as well as 5a.2.6 (and the corresponding opposite approach of the ramp body 5a.2) to engage simultaneously in a slot of a lower contact body and an upper contact body to move the corresponding vertical spreads, i.e., for example, approach 5.2.5 to engage both slot 2.3.5 of contact body 2.3 and slot 2.1.5 of contact body 2.1, the slots must be in the compressed basic configuration ( Fig. 10, 10a ) overlap. Accordingly, a horizontal area 2.1.7, 2.2.7, having slots 2.1.5, 2.1.6 or 2.2.5, 2.2.6, engages vertically within a side wall of the corresponding lower contact body 2.3 or 2.4, resulting in the slots overlapping in their horizontal area, as if the contact bodies 2.1 and 2.3 on the one hand and 2.2 and 2.4 on the other hand were combined. Fig. 8 On the other hand, it is readily apparent.

[0037] The Fig. 12 bis 16 The figures show a further modification of the intervertebral implant from the preceding figures. Identical parts are designated with the same reference symbols. The intervertebral implant of the Fig. 12 bis 16 It also features upper contact bodies 2.1, 2.2 and lower contact bodies 2.3, 2.4. In the Fig. 12 The intervertebral implant 1 is shown in its compressed state, in the Fig. 13 in a state that is expanded - merely - laterally or horizontally.

[0038] The implant 1 initially has linear guides 7.1, 7.2 of the two upper contact bodies 2.1, 2.2 ( Fig. 12, 13 ). Furthermore, it has linear guides 7.3, 7.4 of the two lower contact bodies 2.3, 2.4 ( Fig. 12, 13 , 14 , 16The linear guides 7.1-7.4 serve to guide the upper contact bodies 2.1, 2.2 and the lower contact bodies 2.3, 2.4 laterally or horizontally relative to each other. Furthermore, corresponding vertical linear guides are provided for the contact bodies 2.1 and 2.3 and 2.2 and 2.4, which are located directly above one another, as shown in the illustrations, more precisely in the Fig. 13 , only a vertical linear guide 7.5 of the contact bodies 2.2, 2.4 is shown, which is explained further below.

[0039] Each linear guide 7.1-7.2 consists of a tongue-and-groove guide, in particular a dovetail guide with undercuts, as is the case in particular with guide 7.3 in the Fig. 12, 13 , 16 , the guided tours 7.1 and 7.2 of the Fig. 13 and also the Fig. 15 This is shown and evident. The same applies to section 7.5 of the guide. Fig. 13 .

[0040] Each linear guide accordingly has a groove and a projection or projection engaging in this groove, usually referred to as a "spring". In the case of linear guide 7.1, these are the groove 7.1.1 and the spring 7.1.2; in the case of linear guide 7.2, the groove 7.2.1 and the spring or projection 7.2.2 (each in particular Fig. 13 ). In the case of linear guide 7.3, these are the groove 7.3.1 and the spring 7.3.2, and in the case of linear guide 7.4, the groove 7.4.1 and the spring 7.4.2 (each ). Fig. 16 ).

[0041] In the case of the - vertical - linear guide 7.5, which is in the Fig. 13 As shown, the groove is formed between the two downward-leading guide projections 7.5.1 and 7.5.1a, and the corresponding spring or projection of the guide 7.5 is formed by the side wall 7.5.2 of the lower right support body (from the attack side). The interacting side walls of the projection or spring 7.5.2 and the guide projections 7.5.1, 7.5.1a are also dovetail-shaped with undercuts, as shown in the Fig. 13 as is evident.

[0042] A vertical linear guide for the superimposed support bodies 2.1, 2.3 is designed in the same way as the linear guide 7.5.

[0043] The linear guides ensure that transverse forces are absorbed and, in particular, that the double screw 4 and the threads interacting with it, the wedge body, are relieved or at least relieved of such forces.

[0044] The intervertebral body implant 1 according to the invention is, in all embodiments, basically inserted and placed in the following manner: First, access to the intervertebral body space is created, as described, for example, in WO 2014 / 146797.

[0045] The access sleeve then inserts the intervertebral implant 1 in its compressed state according to the design of the Fig. 5 introduced. This then introduces the intermediate configuration of the Fig. 6, 6a Once the intervertebral implant 1 has reached its position between the two vertebrae, one located below it and one above it, the insertion sleeve is engaged by means of a tool at an actuating element at the proximal end of the intervertebral implant 1, and the threaded body 4 is rotated by the tool. Since the two double wedges 5, 5a cannot rotate, they are moved away from their initial position in opposite directions by the threaded connection between them and the opposing external threads of the threaded body, as occurs during the transition from the Fig. 2 to Fig. 3 as is evident.

[0046] Initially, the ramp bodies 5.2 and 5a.2 engage the corresponding mating surfaces of the contact bodies 2.1-2.4 and move them laterally apart until the mating surface of the contact bodies – for example, 2.4.2 – releases the corresponding ramp, allowing it to move along the support body as the threaded body 4 is further rotated. Simultaneously – i.e., after the support bodies have fully moved laterally apart – the ramp body 5.1 engages the corresponding mating surfaces – such as 2.6 – of the contact bodies with its ramps, so that as the threaded body is further rotated, these surfaces are lifted by the two aforementioned surfaces until the configuration of the Fig. 7, 7a has been achieved.

[0047] In this final step of the process, the contact bodies are moved with their outer side surfaces against the vertebral bodies, thus achieving at least a tension between the vertebral body and intervertebral implant components.

[0048] Because the contact bodies only move against the vertebral bodies in a laterally spread state, the risk of damaging them is significantly reduced or eliminated.

Claims

1. Intervertebral implant - comprising at least two upper and two lower contact bodies (2.1-2.4) having contact surfaces (2.1.1-2.4.1), - comprising an actuator (3) having a threaded body (4) which has an extension axis (A) and is provided with opposite-handed threads (4.1, 4.2) arranged one behind the other, - comprising wedges which sit on the threaded body (4) in an axially moveable manner, can be moved along said threaded body by rotating same, and comprise ramps (5.2.1, 5a.2.1) of at least one ramp body (5.2, 5a.2) of a wedge, which ramps engage at least with counter-surfaces of at least some of the contact bodies and extend toward one another at a finite angle of less than 90°, characterized in that - the wedges are designed as double wedges having, in the direction of the extension axis (A), two ramp bodies arranged one behind the other, - the ramps (5.1.1, 5.1.2; 5a.1.1, 5a.1.2) of one ramp body (5.1, 5.2) are oriented differently to the ramps (5.2.1, 5.2.2, 5a.2.1, 5a.2.2) of the other ramp body (5a.1, 5a.2), - the ramps (5.2.1, 5.2.2; 5a.2.1, 5a.2.2) of the first ramp body (5.2, 5a.2) engage directly with the contact bodies (2.1-2.4) laterally, while the ramps (5.1.1, 5.1.2; 5a.1.1, 5a.1.2) of the second ramp body (5.1, 5a.1) engage directly with the contact bodies (2.1-2.4) in the vertical direction.

2. Intervertebral implant, characterized in that the ramps (5.2.1, 5a.2.1) of the first ramp bodies (5.2, 5a.2) are oriented vertically with a horizontal surface normal (H), and the surface normals (F) of the ramps (5.1.1, 5a.1.1) of the second ramp bodies (5.1, 5a.1), which have a different orientation, include a finite angle other than 90° to the vertical (V).

3. Intervertebral implant according to either claim 1 or claim 2, characterized in that the ramps (5.1.1, 5.2.1 or 5a.1.1, 5a.2.1) of different orientations are arranged on different ramp bodies (5.1, 5.2 or 5a.1, 5a.2).

4. Intervertebral implant according to any of claims 1 to 3, characterized in that counter-surfaces (2.4.1, 2.6) of the contact bodies (2.1- 2.4) that interact with differently oriented ramps (5.1.1, 5.2.1; 5a.1.1, 5a.2.1) and have a different orientation in relation to the spacing of the ramp bodies (5.1, 5.2, 5a.1, 5a.2) have a different spacing in the extension direction of the axis (A) of the threaded body (4) of the actuator.

5. Intervertebral implant according to any of the preceding claims, characterized in that the spacing of the differently oriented ramps (5.1.1, 5.2.1; 5a.1.1, 5a.2.2) relative to the spacing of the counter-surfaces (2.4.2, 2.6) on the contact bodies (2.1-2.4) is such that, when the threaded body (4) rotates, the contact bodies (2.1-2.4) are moved apart from one another at least laterally and are only then raised relative to one another.

6. Intervertebral implant according to any of the preceding claims, characterized in that the spacing of the ramps (5.1.1, 5.2.1; 5a.1.1, 5a.2.1) relative to the spacing of the counter-surfaces (2.4.2, 2.6) is such that the contact bodies (2.1-2.4) first engage laterally with the counter-surfaces (2.4.2) of the contact bodies (2.1-2.4) by means of the ramps (5.2.1, 5a.2.1) of the first ramp body (5.2, 5a.2) in order to move them laterally apart from one another, and only upon further rotation do the ramps (5.1.1, 5a.1.1) of the second ramp body (5.1, 5a.1) engage with the counter-surfaces (2.6) of the contact bodies (2.1-2.4) in order to raise them.

7. Intervertebral implant according to any of the preceding claims, characterized in that the spacing between the differently oriented ramps (5.1.1, 5.2.1; 5a.1.1, 5a.2.1) of a double wedge (5 or 5a) is less than the spacing between the associated counter-surfaces (2.4.1, 2.6).

8. Intervertebral implant according to any of the preceding claims, characterized in that the actuator has a radial disk rigidly connected to the threaded body or has a radial wheel (4.3) which engages in slots (2.5) of the contact bodies (2.1-2.4) that are oriented radially to the axis (A) of the threaded body (4) in order to guide said contact bodies perpendicularly to the axis.

9. Intervertebral implant according to any of the preceding claims, characterized by guide rods which slidably engage at least in the upper contact bodies (2.1, 2.2) and are intended for guiding the contact bodies (2.1, 2.2) relative to one another.

10. Intervertebral implant according to any of the preceding claims, characterized in that the outer contact surface of the upper contact bodies (2.1, 2.2) and the outer contact surface of the lower contact bodies (2.3, 2.4) include an angle of between 5° and 15°, preferably between 9° and 11°.

11. Intervertebral implant, characterized in that the ramp bodies (5.1, 5.2, 5a.1, 5a.2) on a double wedge are formed integrally therewith.

12. Intervertebral implant according to any of the preceding claims, characterized in that contact bodies (2.1, 2.3; 2.2, 2.4 or 2.1, 2.2; 2.3, 2.4) above and / or next to one another are movably connected to one another via linear guides.

13. Intervertebral implant according to claim 12, characterized in that at least one linear guide is a tongue-and-groove guide, preferably a dovetail guide.