Intervertebral implant

Abstract

The invention relates to an intervertebral implant having two upper contact bodies and two lower contact bodies. The contact bodies each have at least one contact surface for bearing against a vertebral body. The intervertebral implant has an actuator with a threaded body which is provided with two threads which run in opposite directions to one another and are arranged axially one behind the other. The actuator has two ramp bodies which are axially movable relative to the actuator by rotation of the actuator about its longitudinal axis. The surfaces of the ramp bodies bear against surfaces of the contact bodies, and the contact bodies are expandable by an axial movement of the ramp bodies toward one another.

Description

[0001] Intervertebral implant

[0002] The invention relates to an intervertebral implant with two upper contact bodies and with two lower contact bodies, wherein the contact bodies each have at least one contact surface for contact with a vertebral body, wherein the intervertebral implant has an actuator with a threaded body which is provided with two threads arranged in opposite directions and axially one behind the other, wherein the actuator has two ramp bodies which are axially movable relative to the actuator by a rotation of the actuator about its longitudinal axis, wherein surfaces of the ramp bodies are in contact with surfaces of the contact bodies.

[0003] German patent DE 10 2020 000 319 A1 describes a generic intervertebral implant whose ramp bodies are arranged on the actuator and connected to the surrounding contact bodies in such a way that the contact bodies expand when the ramp bodies move away from each other due to axial relative movement. In the fully expanded state of the intervertebral implant, the ramp bodies are located at, or at least very close to, the laterally outer end faces of the implant. This results in the disadvantage that the desired ingrowth of bone material into and its connection with the intervertebral implant, which stabilizes the vertebral bodies surrounding the implant, occurs only gradually due to the lateral end faces being closed off by the ramp bodies. This affects the overall implantation process.Furthermore, the ramp bodies have a complex geometry, which makes the manufacturing of the intervertebral implant complex. Additionally, because the ramp bodies are positioned as far apart axially as possible when fully expanded, the load on the intervertebral implant in the axially central region is very high, which is detrimental to the implant's strength.

[0004] The invention is therefore based on the objective of creating an intervertebral implant while avoiding the disadvantages of the prior art, with a particularly simple and mechanically robust design, and with which the implantation process can be accelerated.

[0005] The problem is solved by an intervertebral implant with the features of claim 1, characterized in that the contact bodies can be expanded towards each other by an axial movement of the ramp bodies.

[0006] The invention is based on the fundamental idea that the ramp bodies, which move axially towards each other during the expansion movement of the intervertebral implant, move away from the axial end faces of the intervertebral implant, thereby creating space that can be used for the implantation of the intervertebral implant, in particular for the ingrowth of the bone material. This space is blocked by the ramp bodies themselves in the case of ramp bodies that move axially outwards during the expansion movement of the intervertebral implant.

[0007] In accordance with the invention, the axial center of the intervertebral implant corresponds to the axial center of the actuator, which can thus correspond to a drive mechanism. An axial direction outwards is therefore directed away from the axial center of the actuator, and an axial direction inwards is directed towards it. The axial direction corresponds to the extension or longitudinal direction of the intervertebral implant. In accordance with the invention, an axial direction pointing towards the insertion site of the intervertebral implant is a distal direction, and an axial direction pointing towards the surgeon is a proximal direction. With regard to the use of the intervertebral implant for positioning it between two adjacent vertebral bodies, a vertical direction is directed towards these vertebral bodies. A lateral direction is perpendicular to an axial direction and to a vertical direction in the sense of a three-dimensional Cartesian coordinate system.In accordance with the invention, an expansion movement of the intervertebral implant causes the contact bodies to move away from each other, and a compression movement causes them to move closer together.

[0008] The threaded body can be formed in one piece to achieve a space-saving design and simplify the movement of the contact elements. In a further development of the invention, the threads of the threaded body can be arranged on the same component of the threaded body. Preferably, the ramp elements are screwed directly to the threaded body.

[0009] Preferably, each ramp body has at least one vertical guide surface, wherein the contact body associated with each vertical guide surface has a corresponding vertical counter-surface designed as a cam guide into which the vertical guide surface engages, and the vertical guide surfaces of the ramp bodies are movable within the cam guides during axial movement of the ramp bodies. The movement of the vertical guide surfaces within the cam guides of the contact bodies ensures a defined and guided expansion movement of the intervertebral implant. In an advantageous embodiment of the invention, the vertical guide surfaces can be captive within their associated cam guides.

[0010] Preferably, at least one ramp body, and in particular both ramp bodies, each has four vertical guide surfaces that engage in the cam guides of the four contact bodies. In a further development of the invention, it can be provided that the ramp bodies are directly connected to the contact bodies. In particular, a direct functional connection is formed between the ramp bodies and the contact bodies to simplify the design of the intervertebral implant, since fewer components are required. In this respect, it can be provided that the ramp bodies are in direct contact with the contact bodies, in particular during the entire movement of the intervertebral implant.

[0011] Preferably, the vertical guide surface has an inclination about a lateral axis relative to the horizontal of a non-zero degree. The angle of inclination of the vertical guide surface can be at least 15° and / or at most 45°, in particular between 15° and 45°, preferably approximately 30°. The vertical guide surface can have a normal that is axially oriented inwards and vertically outwards and / or that has no lateral directional component.

[0012] Preferably, the vertical guide surface has at least one projection, which is trapezoidal in profile, and it is particularly provided that at least one recess is arranged laterally adjacent to the projection. The projection increases the contact area between the vertical guide surface of the ramp body and the corresponding vertical counter-surface of the contact body, acting as a cam guide, and enables more precise control of the expansion movement of the intervertebral implant.

[0013] Preferably, the projection in the profile forms a right-angled trapezoid, wherein it is particularly provided that its laterally inner leg is vertically oriented and / or wherein its laterally outer leg is vertically oriented outwards and laterally inwards. In the latter case, the normal associated with the laterally outer leg points laterally and vertically outwards. In a further development of the invention, it may be provided that the normal associated with the laterally outer leg has no axial directional component.

[0014] Preferably, each vertical guide surface has two laterally arranged, trapezoidal profile projections, which are in particular identical to each other in order to increase the contact area between the ramp body and the base body associated with it.

[0015] Preferably, the vertical guide surfaces are arranged on the top and bottom of the ramp body, and in particular only on the top and bottom. A horizontal intermediate area with a normal, preferably oriented only vertically, can be formed between two laterally adjacent vertical guide surfaces of the ramp body. This intermediate area can be located vertically at the level of the recesses of the vertical guide surfaces. Preferably, the vertical guide surface has a guide projection, preferably arranged in a corner region of the ramp body. It is particularly provided that all vertical guide surfaces have a guide projection in each corner region of the ramp body. The guide projection can have the same inclination as the corresponding vertical guide surface of the ramp body.A vertically oriented region can be arranged between two vertically stacked guide projections, the normal of which has no vertical directional component and / or no axial directional component. The guide projection can have an axial length of approximately 2 mm. The axial length of the guide projection can correspond to approximately half the axial length of the ramp body associated with the guide projection. The guide projection can have a rectangular base and / or be arranged in at least one corner region of the ramp body associated with the guide projection. In a further development of the invention, the guide projection can be beam-shaped. To optimize force transmission during the expansion movement of the intervertebral implant, the guide projection, and in particular all guide projections, can be arranged axially centered relative to the associated ramp body.

[0016] Preferably, the guide projection has a vertical inclination to the horizontal of a non-zero degree and / or is preferably arranged in a vertical plane. The vertical angle of inclination of the guide projection to the horizontal can be at least 15° and / or at most 45°, in particular between 15° and 45°, preferably approximately 30°. The guide projection can be vertically oriented and have an angle of inclination of 0° to a vertical plane. In a further embodiment, the guide projection has no lateral inclination. The direction of extension of the guide projection can be arranged in a plane spanned by an axial and a vertical direction.

[0017] Preferably, the guide projections are each arranged in a corner region of the ramp body. In a further development, it is possible for all guide projections to be arranged in a corner region of the ramp bodies. In a further development of the invention, the two ramp bodies each have guide projections that can be arranged in the corner regions of the ramp bodies. The at least one guide projection can be spaced apart from the axially outer end face of the ramp body. This spacer can be at least 1 mm. The guide projection, and in particular all guide projections, can be formed integrally with the ramp body to which they are associated.

[0018] Preferably, the vertical guide surfaces of the ramp bodies engage at least partially in a form-fitting manner with the cam guides of the contact bodies to simplify the guidance of the ramp bodies along the cam guides. In a further development of the invention, it can be provided that the cam guide, as a vertical counter-surface to the vertical guide surface of the ramp body, has a recess associated with the guide projection of the ramp body, in which the guide projection can be movably arranged and / or which the guide projection can engage. This prevents horizontal expansion movement of the intervertebral implant during its vertical expansion movement, thus ensuring controlled expansion of the intervertebral implant.

[0019] Preferably, the cam guide of the contact body is designed to correspond to the vertical guide surface of the ramp body associated with the contact body. In this respect, the cam guide of the contact body can be associated with the vertical expansion movement of the intervertebral implant. With regard to the cam guide, the vertical guide surface can be designed as a sliding surface to increase the contact area between the ramp body and the associated contact body. This increases the frictional resistance, particularly during the expansion movement of the intervertebral implant, thus providing a self-locking effect that increases the reliability of the insertion, especially during the expansion movement of the intervertebral implant. The vertical guide surface can be in captive engagement with the cam guide.

[0020] Preferably, the cam guide of the contact body is arranged parallel to the vertical guide surface of the ramp body assigned to the contact body.

[0021] Preferably, each ramp body has at least one lateral guide surface for contact with a corresponding lateral counter surface of the contact body associated with the ramp body, wherein, in particular, the normal of the lateral guide surface is inclined relative to a lateral direction. The normal of the lateral guide surface can be oriented axially inwards and vertically outwards and / or have no vertical directional component. The normal of the lateral guide surface can be arranged perpendicular to a vertical axis. The lateral guide surface of the ramp body and the corresponding lateral counter surface of the contact body can be associated with and facilitate the lateral expansion movement of the intervertebral implant.The lateral guide surface of the ramp body can be arranged parallel to the lateral mating surface of the contact body and / or be movable relative to it. The lateral guide surface of the ramp body can be designed as its lateral side surface and / or be arranged axially offset inwards from the guide projection associated with the lateral guide surface. The angle between the normal of the lateral guide surface and a lateral direction can be at least 15° and / or at most 45°, in particular between 15° and 45°, preferably approximately 30°. Preferably, each ramp body has at least two lateral guide surfaces. The lateral guide surface of the ramp body can be in contact with the contact body associated with the ramp body, in particular with its lateral mating surface.The lateral guide surface of the ramp body can be movable relative to the corresponding lateral counter surface of the contact body. In a further development of the invention, each lateral guide surface of the ramp body can be associated with a lateral counter surface of two contact bodies assigned to the lateral side surface. The lateral guide surface of the ramp body can be designed to guide, in particular, the lateral expansion movement of the intervertebral implant. This enables the intervertebral implant to first perform a horizontal expansion movement and then a vertical expansion movement when the ramp bodies move axially towards each other. The expansion movement of the intervertebral implant can be structurally determined by the arrangement of the lateral guide surfaces of the ramp body relative to its vertical guide surfaces, in particular relative to the guide projections.

[0022] Preferably, the lateral mating surface of the contact body is spaced apart from its axial end face. In a further development of the invention, the lateral mating surface of the contact body can be arranged axially in the region of the vertical mating surface. The lateral mating surface can be arranged approximately in an axially outer end region of the vertical mating surface. The vertical mating surface of the contact body can be spaced apart from its axial end face.

[0023] Preferably, the actuator has a radially centered opening, which is designed to allow the passage of a guide wire during movement of the intervertebral implant, particularly during its implantation. This enables minimally invasive implantation of the intervertebral implant, especially when using a guide wire designed to correspond to the opening. This advanced implantation technique is also called "over-the-wire". The actuator may have at least one, and preferably two, laterally oriented openings to facilitate the easy insertion of bone substitute material into the intervertebral space via the radially centered opening, particularly in combination with the openings of the contact bodies. For this purpose, the opening may be designed to communicate with the axial recess.In a further development of the invention, the ramp bodies can each have a particularly radially centered opening through which the actuator passes, wherein the openings of the ramp bodies can each have an internal thread matched to the thread of the actuator associated with the ramp body.

[0024] Preferably, the upper surface and / or the lower surface of the ramp body, in particular their vertical guide surfaces, taper inwards in an axial direction, particularly linearly. In this respect, the upper surface and / or the lower surface of the ramp body can be designed as guide surfaces for the vertical expansion movement of the intervertebral implant. The angle of inclination of the upper surface and / or the lower surface of the ramp body relative to the horizontal plane can be at least 15° and / or at most 45°, in particular between 15° and 45°, preferably approximately 30°. The angle of inclination of the upper surface can be equal in magnitude to the angle of inclination of the lower surface. In a further embodiment of the invention, the angle of inclination of the upper surface of the ramp body relative to the horizontal plane can be equal to the angle of inclination of the guide projection associated with the upper surface of the ramp body relative to the horizontal plane.The same applies to the angle of inclination of the underside of the ramp body relative to the angle of inclination of the guide projection associated with the underside of the ramp body. Furthermore, it can be provided that the angle of inclination of the top of the ramp body corresponds to the angle of inclination of the cam guide of the contact body associated with the ramp body. The same applies to the angle of inclination of the underside of the ramp body in relation to the angle of inclination of the cam guide of the contact body associated with the ramp body. At least one lateral side surface of the ramp body, in particular its lateral guide surface, can be designed to taper inwards, at least partially, in the axial direction.The axially outer end face of the ramp body and / or the axially inner end face of the ramp body can be vertically oriented so that their normals are arranged in a horizontal plane, in particular parallel to an axial direction. The ramp bodies of the actuator can be arranged and / or designed to be point-symmetrical with respect to the axial center of the actuator.

[0025] Preferably, at least one contact body has a vertical guide body configured for sliding engagement in a vertical recess of the contact body vertically adjacent to the vertical guide body, and / or at least one contact body has a lateral guide body configured for sliding engagement in a lateral recess of the contact body laterally adjacent to the vertical guide body. In particular, it can be provided that each contact body has a lateral guide body, a lateral recess, a vertical guide body, and a vertical recess. This allows each contact body to be connected to both its vertically adjacent and its laterally adjacent contact body.With the aid of the guide bodies and the corresponding recesses, a particularly uniform guidance of the contact bodies relative to each other is achieved. Each contact body can have an outer surface designed for contact with a vortex body. The outer surfaces of the contact body, in particular of each contact body, can be closed. Two adjacent contact bodies can be captive connected to each other. In particular, each contact body can be captive connected to the contact bodies adjacent to it.

[0026] At least one contact body can have at least one vertically oriented recess, particularly on its laterally facing inward side, to facilitate the insertion of bone substitute material into the intervertebral space into which the intervertebral implant is inserted after implantation. The recess thus promotes the growth behavior of the bone substitute material. Preferably, each contact body has a vertically oriented recess, in particular two recesses arranged axially one behind the other. The recesses of two laterally adjacent contact bodies can interact in such a way that, in the case of a compressed intervertebral implant, the recesses form a common, in particular round, recess.

[0027] Preferably, at least one contact body has a locking mechanism for the axial movement of the ramp body associated with it. In particular, the locking mechanism is associated with the proximal ramp body. The locking mechanism can be designed as a threaded pin that can be screwed through a threaded recess in the contact body and is configured to limit the expansion movement of the intervertebral implant when screwed in. This prevents uncontrolled expansion of the intervertebral implant that could lead to accidental disassembly. The recess in the contact body can be vertically oriented.The recess of the contact body can be arranged axially offset inwards relative to the associated ramp body, in particular to its guide projection, and the locking mechanism can be designed to engage with the ramp body, in particular with its guide projection. The recess of the contact body can be arranged adjacent to the vertical counter surface, in particular between the vertical counter surface and the vertical recess or the vertical guide body. For example, a threaded pin screwed into the recess can prevent further movement of the ramp body by means of a positive locking engagement with the guide projection of the ramp body. The locking mechanism can also include a bolt that can be arranged in the recess.

[0028] The at least one contact body may have a taper at an outer, particularly distal, end region to facilitate the insertion of the intervertebral implant. At least two, and in particular all, contact bodies of the intervertebral implant may be designed symmetrically to each other, particularly with respect to the center point of the actuator and / or with respect to a plane of symmetry, which is in particular horizontally and / or vertically oriented.

[0029] The actuator can extend substantially in the axial direction and / or have an axial opening for the passage of a guide wire to implant the intervertebral implant during a minimally invasive procedure. The actuator can have a guide wheel that is fixedly, and in particular rotationally, connected to the actuator and can be manually actuated. The guide wheel can extend over a circumferential range of 360° and thus be designed as a ring. To achieve a compact design of the intervertebral implant, the contact body, and in particular all contact bodies, can have slots associated with the guide wheel, in particular transverse slots, into which the guide wheel can engage for axial guidance. In a further development of the invention, the threads of the actuator may not extend over its entire axial length.The guide wheel can be designed for axial locking, in particular for axial centering, of the contact body and / or the actuator.

[0030] Preferably, in the case of ramp bodies moving axially towards each other, the contact bodies are first movable laterally, in particular only laterally, and subsequently vertically, in particular only vertically.

[0031] The intervertebral implant can be manufactured using an additive manufacturing process, in particular a laser beam melting process. Most preferably, the intervertebral implant can be manufactured using selective laser melting, also known as "SLM" ("Selective Laser Melting"). In particular, the outer surfaces of the intervertebral implant, especially the outer surfaces of the contact bodies, can be manufactured using selective laser melting to improve bone fusion and thus overall implantation. Following the additive manufacturing process, the intervertebral implant can be post-processed by machining, in particular by milling.This post-processing refers to the leading surfaces of the components of the intervertebral implant, such that at least one of the following components of the intervertebral implant may be post-processed: guide surfaces, mating surfaces, threads, lateral side surfaces, proximal end face, and recess for the expansion instrument. In the compressed state of the intervertebral implant, the ramp bodies, with the exception of their axial openings, may be completely surrounded by the contact bodies. In application, the intervertebral implant may be implantable in the compressed state between two adjacent vertebral bodies. In this position, its expansion movement, particularly in the lateral and vertical directions, may be initiated. In the fully expanded state, the intervertebral implant may be in contact with the vertebral bodies.The vertebral bodies can then be braced against each other with the aid of the intervertebral implant. After implantation, the intervertebral implant can be positioned between two adjacent vertebral bodies. Therefore, the lateral expansion movement of the intervertebral implant is less dangerous for the vertebral bodies than its vertical expansion movement. Thus, by first a lateral expansion movement and only then a vertical expansion movement of the intervertebral implant, the risk of damage to the vertebral bodies is reduced.

[0032] Preferably, only a single actuator is provided for the lateral expansion of the contact body and for the vertical expansion of the contact body.

[0033] Preferably, the proximal end face of the actuator has a recess for an expansion element to initiate the axial movement of the ramp bodies towards each other and thereby cause the expansion movement of the contact bodies. The recess can be designed for positive engagement with the expansion element and / or as an internal hexagon or internal hexagonal profile. The recess can be equipped with an anti-rotation device, which can be designed, for example, as at least one lateral recess, and in particular as two lateral recesses. In a further embodiment of the invention, the proximal end faces of the contact bodies each have a lateral recess, in particular a pocket-shaped one, into which the expansion element can engage positively to prevent rotation of the contact bodies when the expansion element is actuated. The recess thus serves as an anti-rotation device.

[0034] Preferably, in the expanded state of the intervertebral implant, two vertically adjacent contact bodies on one lateral side have a distance from each other that is greater than the distance between the two vertically adjacent contact bodies on the other lateral side.

[0035] Preferably, in the expanded position of the intervertebral implant, at least one of the contact bodies is tilted relative to the compressed position of the intervertebral implant. This can apply to two contact bodies, particularly horizontally adjacent ones, or, in a further development of the invention, to all contact bodies. The tilting can occur about an axially and / or vertically oriented axis. In particular, in the preferably laterally implanted state of the intervertebral implant, a greater, particularly symmetrical, ventral expansion of the intervertebral implant can occur than dorsally. In a further development of the invention, a lateral and / or dorsal and / or dorsolateral expansion of the intervertebral implant can occur in the implanted state.

[0036] Further advantages and features of the invention will become apparent from the claims and the following description, in which an embodiment of the invention is explained in detail with reference to the drawing. The drawing shows:

[0037] Fig. 1 shows an intervertebral implant according to the invention in a schematic exploded view.

[0038] Fig. 2 shows an actuator of the intervertebral implant according to Fig. 1 with expanded ramp bodies in a perspective view from an oblique angle above,

[0039] Fig. 3 shows the actuator according to Fig. 2 in a side view,

[0040] Fig. 4 shows the actuator according to Fig. 2 with compressed

[0041] Ramp bodies in a perspective view from a slanted top,

[0042] Fig. 5 shows the actuator according to Fig. 4 in a side view,

[0043] Fig. 6 shows a ramp body in a perspective view

[0044] View from a slightly elevated angle,

[0045] Fig. 7 of the ramp body according to Fig. 6 in a top view,

[0046] Fig. 8 of the ramp body according to Fig. 6 in a side view,

[0047] Fig. 9 of the ramp body according to Fig. 6 in a view from a rear oblique angle,

[0048] Fig. 10 shows a contact body of the intervertebral implant according to Fig. 1 in a perspective view, Fig. 11 shows the contact body according to Fig. 10 in a perspective view from an oblique front view,

[0049] Fig. 12 shows a contact body with threaded pin in a side view,

[0050] Fig. 13 shows the contact body according to Fig. 12 in a longitudinal section,

[0051] Fig. 14 shows the intervertebral implant according to Fig. 1 in a compressed state,

[0052] Fig. 15 shows a partial section of the intervertebral implant according to Fig. 14,

[0053] Fig. 16 shows a cross-section through the intervertebral implant according to Fig. 14 in a perspective view,

[0054] Fig. 17 shows the intervertebral implant according to Fig. 14 in a sectional view at the level of the ramp bodies,

[0055] Fig. 18 shows a contact body with a ramp body of the intervertebral implant according to Fig. 14 in a partial section,

[0056] Fig. 19 shows the intervertebral implant according to Fig. 14 in a horizontally expanded state,

[0057] Fig. 20 shows the intervertebral implant according to Fig. 19 in a partial section, Fig. 21 shows a cross-section through the intervertebral implant according to Fig. 19 in a perspective view,

[0058] Fig. 22 shows a cross-section of the intervertebral implant according to Fig. 19 in a distal view,

[0059] Fig. 23 shows a cross-section of the intervertebral implant according to Fig. 19 in a proximal view,

[0060] Fig. 24 shows the intervertebral implant according to Fig. 19 in a vertically expanded state,

[0061] Fig. 25 shows the intervertebral implant according to Fig. 24 in a partial section,

[0062] Fig. 26 shows a cross-section through the intervertebral implant according to Fig. 24 in a distal view.

[0063] Fig. 27 shows a cross-section through the intervertebral implant according to Fig. 24 in a proximal view,

[0064] Fig. 28 shows the intervertebral implant according to Fig. 1 in a compressed state,

[0065] Fig. 29 shows the intervertebral implant according to Fig. 28 in a horizontally expanded state and

[0066] Fig. 30 shows the intervertebral implant according to Fig. 29 in a vertically expanded state.

[0067] Fig. 1 shows an exploded view of an intervertebral implant 1 according to the invention. The intervertebral implant 1 has a centrally arranged actuator 2 or drive mechanism with a central threaded body 3, which has two opposing threads 4, 5 arranged axially one behind the other on the actuator 2. Two wedge-shaped ramp bodies 6, 7, which are axially movable relative to the actuator 2, are arranged on the actuator 2 in the region of the threads 4, 5. The ramp bodies 6, 7 engage the threads 4, 5 such that the ramp bodies 6, 7 rotate when the actuator rotates.

[0068] The ramp bodies 6 and 7 are symmetrical to each other. The actuator 2 has a guide wheel 8, which is rotationally fixed to it, acting as an axial detent for the components of the intervertebral implant 1. The actuator 2 has an axially oriented longitudinal section and an axially centered opening 9 extending over the entire length of the actuator 2 to allow implantation of the intervertebral implant 1 using a guide wire (not shown in Fig. 1) in a minimally invasive procedure, also known as "over-the-wire".

[0069] In accordance with the invention, an axial direction A, shown as a dashed line in Fig. 1, is parallel to the extension direction of the actuator 2 and thus to the extension direction of the intervertebral implant 1. A lateral direction is perpendicular to the axial direction A, but is also horizontally oriented. A horizontal plane is defined by an axial direction and a lateral direction. A vertical direction is perpendicular to the horizontal plane. The axial center point corresponds to the center point of the actuator 2, which corresponds to the axial height of the guide wheel 8. An axial inward direction is therefore oriented toward the guide wheel 8, while an axial outward direction points away from it. An axial direction toward the insertion site points distally, and an axial direction toward the surgeon points proximally. In this respect, the front ramp body 6 in Fig. 1 is arranged distally, and the rear ramp body 7 is arranged proximally.

[0070] The actuator 2 is surrounded by four contact bodies 10, 11, 12, 13: two upper contact bodies 10, 11 and two lower contact bodies 12, 13. The two upper contact bodies 10, 11 are arranged in a common horizontal plane, which differs from the common horizontal plane of the two lower contact bodies 12, 13. Similarly, the two left contact bodies 10, 12 are arranged in a common vertical plane, which differs from the vertical plane of the two right contact bodies 11, 13. The contact bodies 10, 11, 12, 13 completely surround the actuator 2. In the implanted state, the intervertebral implant 1 is positioned between two adjacent vertebral bodies (not shown in Fig. 1), with the contact bodies 10, 11, 12, 13 in contact with the vertebral bodies.

[0071] Fig. 2 shows the actuator 2 with the ramp bodies 6, 7, which are movable relative to it and axially and are in an expanded position corresponding to the compressed position of the intervertebral implant 1. The actuator 2 has two lateral openings 2a, 2b, with the first opening 2a being located between the thread 4 and the guide wheel 8 and the second opening 2b being located between the thread 5 and the guide wheel 8. The openings 2a, 2b serve to introduce bone substitute material inserted via the axial opening 9. As already described, the ramp bodies 6, 7 are symmetrical to each other and therefore have identical features. Their features are therefore described below essentially in relation to the anterior, distal ramp body 6 in Fig. 2. The ramp body 6 has an axially outwardly pointing, vertical end face 14, the normal of which is aligned parallel to an axial direction.The ramp body 6 has a first lateral surface 15, which serves as a sliding surface with respect to the lateral expansion movement of the intervertebral implant 1, as described below. The normal of the first lateral surface 15 is oriented parallel to a lateral direction, so that the first lateral surface 15 is perpendicular to the outer end face 14 of the ramp body 6. The first lateral surface 15 transitions axially inwards to a second lateral surface 16, the normal of which is inclined relative to the normal of the first lateral surface 15, and thus relative to a lateral direction, so that the second lateral surface 16 tapers axially inwards.The second lateral surface 16 is aligned parallel to a lateral counter-surface 28 of the contact body 13 associated with the ramp body 6 and transitions axially inwards into a third lateral surface 17, which is oriented laterally, and thus parallel to, the first lateral surface 15. Finally, the third lateral surface 17 transitions axially inwards into an inner end face 18 of the ramp body 6, which is aligned parallel to its outer end face 14.

[0072] The ramp body 6 has a top surface 19 that tapers inwards in the axial direction and a bottom surface 20 that also tapers inwards in the axial direction. The top surface 19 and the bottom surface 20 each have two vertical guide surfaces 23, which are assigned to the cam guides 27 as vertical counter surfaces 29 of the contact bodies 10, 11, 12, 13 associated with the ramp body 6 and movably engage with them. The features of the vertical guide surfaces 23 are described with reference to the vertical guide surface 23 of the front ramp body 6 located in the upper left of Fig. 2; the remaining vertical guide surfaces of the ramp body 6, as well as the vertical guide surfaces 23 of the rear ramp body 7 in Fig. 2, are designed accordingly.The vertical guide surface 23 has two laterally adjacent projections 21, each of which has the basic shape of a right-angled trapezoid in profile, since the laterally inner leg 21a is vertically oriented, while the laterally outer leg 21b is vertically outward and laterally inward. The projections 21 are therefore inclined laterally inward. A recess 22 is arranged between each projection 21. The projections 21 are arranged laterally offset from the actuator 2 and are aligned parallel to the surface of the upper surface 19, thus inclined relative to the horizontal plane. A horizontal intermediate section 23b is arranged between two laterally adjacent vertical guide surfaces 23.The vertical guide surfaces 23, which have projections 21, are associated with the vertical expansion movement of the intervertebral implant 21 and movably engage with vertical counter-surfaces 29 of the contact bodies 10, 11, 12, 13. The projections 21, together with the recesses 22 and the lateral side surfaces 15, 16, 17, serve as sliding surfaces to increase the friction with the contact bodies 10, 11, 12, 13 that are in contact with them. The ramp body 6 has a beam-shaped guide projection 23a in each of its four corner regions. The four guide projections 23a are arranged parallel to the surface of the upper surface 19 associated with the guide projection 23 and to the lower surface 20 of the ramp body 6, and are each designed to engage with the contact bodies 10, 11, 12, 13 associated with the ramp body 6, as described below. The same applies to the rear, proximal ramp body 7 in Fig. 2.The ramp bodies 6, 7 each have an opening 24 provided with an internal thread 24a (not shown in Fig. 1), the internal thread 24a corresponding to the threads 4, 5 of the actuator 2. The internal thread 24a of the opening 24 is shown in Fig. 6. This allows the ramp bodies 6, 7 to move in opposite axial directions during a rotational movement of the actuator 2, i.e., towards or away from each other. In Fig. 2, the ramp parts 6, 7 are shown in an axially expanded position on the actuator 2. This position corresponds to the compressed position of the intervertebral implant 1. Fig. 3 shows the actuator 2 with the ramp parts 6, 7 expanded according to Fig.2 in a side view, in which in particular the positions of the ramp parts 6, 7 relative to the guide wheel 8 as well as the orientation of the end faces 14, 18, the side surfaces 15, 16, 17, the top 19 and the bottom 20 of the ramp bodies 6,7 are shown.

[0073] Fig. 4 shows the actuator 2 in a perspective view, similar to Fig. 2, but here with compressed ramp bodies 6, 7, which are therefore moved axially towards each other and have a smaller axial distance to the guide wheel 8. In this position, the intervertebral implant 1 associated with the actuator 2 is expanded. The illustration in Fig. 4 also shows that the proximal end face 42 of the actuator 2 has an internal hexagonal recess 41 for an expansion instrument (not shown) with an external hexagonal shape, with which the actuator 2 can be actuated to initiate the expansion movement of the intervertebral implant 1. For clarity, the recess 41 of the actuator 2 is not shown in Fig. 2. Fig. 5 shows the actuator 2 according to Fig. 4 in a side view, from which in particular the ramp bodies 6, 7 of the actuator 2 which move axially towards each other can be seen.Regarding the other features of actuator 2, reference is made to the descriptions of Fig. 2 and Fig. 3 to avoid repetition.

[0074] The ramp body 6 is shown individually in Fig. 6 in a perspective view, in Fig. 7 in a top view, in Fig. 8 in a side view, and in Fig. 9 in a perspective view from an oblique inside. In particular, Fig. 6 shows the opening 24 of the ramp body 6, which is provided with the internal thread 24a and is arranged laterally and vertically centered.

[0075] The contact bodies 10, 11, 12, 13 are arranged around the actuator 2 as shown in Fig. 1. Each contact body 10, 11, 12, 13 has essentially the same features, so their features are described below with reference to contact body 11, located in the upper right of Fig. 1, which is shown individually in Figs. 10 and 11. Contact body 11 has a tapered section 26 at a front, distal end 25 to facilitate the insertion of the intervertebral implant 1 between the vertebral bodies. At a distance from its axial, here proximal, end face 28a, the contact body 11 has a cam guide 27 associated with the ramp body 6, in particular its vertical guide surface 23 on its upper surface 19, into which the vertical guide surface 23, in particular its projections 21 and its guide projection 23a, movably engages.The vertical guide surface 23 engages in a corresponding vertical counter-surface 29 of the cam guide 27 of the contact body 11 and is movable therein, with an undercut 29a of the cam guide 27 forming for engagement by the guide projection 23a of the ramp body 6. The cam guide 27 together with its vertical counter-surface 29 is associated with the vertical expansion movement of the intervertebral implant 1. In the region of the proximal end face 28a, the contact body 11 has a pocket-shaped lateral recess 40 into which the expansion instrument can be positively engaged.

[0076] Axially, approximately at the level of the guide rail 27, the contact body 11 has a lateral counter-surface 28 corresponding to the lateral side surface 16 of the ramp body 6, which is assigned to the horizontal expansion movement of the intervertebral implant 1. The lateral side surfaces 16 of the ramp body 6 thus serve as lateral guide surfaces for the lateral expansion movement of the intervertebral implant 1 and are in contact with the correspondingly designed lateral counter-surfaces 28 of the contact body 11 assigned to the ramp body 6. The same applies to the other lateral side surfaces 16 of the ramp bodies 6, 7 and the correspondingly designed lateral counter-surfaces 28 of the contact bodies 10, 11, 12, 13.

[0077] Due to the vertical orientation of the cam guide 27 with its vertical counter-surface 29, the expansion movement of the intervertebral implant 1 is vertically oriented, so that the contact body 11 moves vertically away from the actuator 2 and from the vertically adjacent contact body 10. The vertical counter-surface 29 of the contact body 11, which corresponds to the vertical guide surface 23 of the ramp body 6, provides a comparatively large contact area between the ramp body 6 and the contact body 11, thus enabling targeted control of the vertical expansion movement of the intervertebral implant 1. The engagement of the vertical guide surface 23 of the ramp body 6 with the vertical counter-surface 29 of the contact body 11 ensures that horizontal expansion movement of the intervertebral implant 1 is prevented during its vertical expansion movement.Due to the arrangement of the cam track 27 of the contact body 11 relative to its lateral counter surface 28, the intervertebral implant 1 is designed to initiate a lateral expansion movement first and only then a vertical expansion movement.

[0078] According to Figures 10 and 11, the contact body 11 has a laterally oriented guide body 30 arranged axially behind the cam guide 27, the base of which approximately corresponds to a rectangle with rounded corners. The length of the lateral guide body 30 projecting from the contact body 11 is greater than the expansion path in the lateral direction. The lateral guide body 30 of the contact body 11 is formed corresponding to a lateral recess 31 of the contact body 10 laterally adjacent to the contact body 11, so that the lateral guide body 30 engages positively in the recess 31 in the compressed state of the intervertebral implant 1 and gradually moves out of the lateral recess 31 during the expansion movement of the intervertebral implant 1, particularly during its lateral expansion movement. The lateral recess 31 of the laterally adjacent contact body 10 is shown in Fig.1 shown and designed accordingly to the recess 31 of the contact body 11 according to Figs. 10 and 11.

[0079] According to Figures 10 and 11, the contact body 11 has a vertically oriented guide body 32 axially behind the cam guide 27. Similar to the lateral guide body 30, the guide body 32 has a rectangular base with rounded corners; however, the base of the vertical guide body 32 is wider than that of the lateral guide body 30. The vertical guide body 32 is provided with a vertical recess 33 for engagement with the contact body 13, which is vertically adjacent to the contact body 11. The vertical guide body 32 of the contact body 11 is itself surrounded by a vertical recess 33, which is designed for engagement with the vertical guide body 32 of the vertically adjacent contact body 10.The vertical guide body 32 and the associated vertical recess 33, similar to the lateral guide body 30 and the associated recess 31, serve to guide the contact bodies 10, 11, 12, 13 relative to each other during the vertical expansion movement of the intervertebral implant 1. In the embodiment shown in Fig. 1, each contact body 10, 11, 12, 13 has a vertical guide body 32 and an associated vertical recess 33. The vertical guide bodies 32 of the upper contact bodies 10, 11 are longer than the expansion path in the vertical direction. Axially between the lateral guide body 30 and the lateral recess 31, the contact body 11, as shown in Fig. 1, has a vertical guide body 32. 1 a transverse slot 34 for the guide wheel 8 of the actuator 2 in order to accommodate it without hindering its rotational movement. Fig. 12 shows the one in Fig.Figure 12 shows a perspective side view of the contact body 12, located at the bottom left, which reveals that the contact body 12 has a vertically oriented threaded bore 35 through which a threaded pin 36, shown separately from the contact body 12 in Figures 1 and 12, can be screwed. Figure 13 shows the contact body 12 with the threaded pin 36 screwed in, the threaded pin 36 being arranged proximal to the vertical guide body 32. The threaded pin 36 screwed into the threaded bore 35 serves as a locking device 36 for the expansion movement of the intervertebral implant 1, since in the embodiment of Fig. 1 the rear, i.e. proximal, ramp body 7, which moves axially inwards towards the guide wheel 8 during the expansion movement of the intervertebral implant 1, comes into contact with the threaded pin 36, in particular the guide projection 23a of its vertical guide surface 23. This state is shown in Fig. 13.Further axial movement of the ramp body 7 inwards, and thus also further expansion of the intervertebral implant 1, is blocked there. Since an unhindered expansion movement would result in the disintegration of the intervertebral implant 1, the threaded pin 36 serves as a disassembly protection device.

[0080] Fig. 14 shows an intervertebral implant 1 according to the invention in a compressed perspective view, and Fig. 15 shows this state according to Fig. 14 in a partial section in which the upper left contact body 10 (viewed from distally) has been removed to reveal the actuator 2. In this state, the ramp bodies 6, 7 are axially as far apart as possible, but still surrounded by the contact bodies 10, 11, 12, 13. With the exception of an axial recess 37 for the guide wire and two vertical recesses 38, 39, which are provided for introducing bone substitute material supplied by the cannulated actuator 2 into the intervertebral space and are visible on the upper surfaces of the upper contact bodies 10, 11 according to Fig. 14, the surface of the intervertebral implant 1, and thus in particular the surfaces of the contact bodies 10, 11, 12, 13, is closed.Further expansion of the ramp bodies 6, 7 on the actuator 2 is prevented by the engagement of the ramp bodies 6, 7 with the associated contact bodies 10, 11, 12, 13. The lateral and vertical guide bodies 30, 33 of the contact bodies 10, 11, 12, 13 are each in full engagement with the corresponding lateral and vertical recesses 31, 32.

[0081] Fig. 16 shows a cross-section through the intervertebral implant 1 according to Fig. 14 with the upper contact bodies 10, 11 removed, at the axial height of the posterior ramp body 7, in a perspective view. This view particularly reveals the profile of the vertical guide surfaces 23 with their projections 21 and guide projections 23a, as well as the profile of the corresponding cam guides 27 of the contact bodies 12, 13 with the vertical counter-surfaces 29 and the undercuts 29a. The compressed state of the intervertebral implant 1 is also evident from the fact that the lower contact bodies 12, 13, as well as the upper contact bodies 10, 11 (not shown), are in contact with one another. Fig. 17 shows a cross-section through the intervertebral implant 1 through the proximal ramp body 7 with inset contact bodies 10, 11, 12, 13 from a proximal view.Figure 18 shows a partial section through the intervertebral implant 1 in a perspective view, from which the engagement of the guide projections 23a of the ramp body 7 with the undercuts 29a of the vertical mating surfaces 29 of the contact body is particularly evident. Figure 16 also shows the internal thread 24a of the ramp body 7, which has already been explained in connection with the ramp body 6 shown in Figure 6, and the threaded pin 36 of the contact body 12, which has also already been explained.

[0082] In the transition from Fig. 14 to Fig. 19, the actuator 2 was actuated by an expansion tool (not shown), for example, an external hexagon, which engages in the recess 42 shown in Fig. 4 on the proximal end face 41 in the form of an internal hexagon and is then rotated about its longitudinal axis, in order to trigger the expansion movement of the intervertebral implant 1. Fig. 20 shows a partial section of Fig. 19 with the contact body 10 removed at the top left. Actuation of the actuator 2 causes it to rotate about the axial direction, so that the ramp bodies 6, 7 move axially towards each other. Due to the interaction of the lateral side surfaces 16 of the ramp bodies 6, 7 as lateral guide surfaces with the lateral counter surfaces 28 of the contact bodies 10, 11, 12, 13, a lateral expansion movement of the intervertebral implant 1 initially takes place.The contact bodies 10, 11, 12, 13 initially move laterally, each moving away from the actuator 2. The lateral guide bodies 30 move out of their associated lateral recesses 31, while the vertical guide bodies 33 remain fully engaged with their associated vertical recesses 32. No vertical expansion movement of the contact bodies 10, 11, 12, 13 yet takes place.

[0083] Accordingly, in Fig. 21, which, similar to Fig. 16, shows a section through the intervertebral implant 1 with the upper contact bodies 10, 11 obscured at the axial level of the posterior ramp body 7 from a proximal view, the lower contact bodies 12, 13 are laterally spaced apart. The vertical guide surfaces 23 of the proximal ramp body 7 engage with the vertical counter-surfaces 29 of the contact bodies 12, 13. The same applies to the distal ramp body 6 (not shown in Fig. 21) and to the upper contact bodies (not shown in Fig. 21).

[0084] 10, 11. In addition, the lateral counter surfaces 28 of the contact bodies 12, 13 associated with the lateral side surfaces 16 of the ramp body 6 (not shown) are visible in Fig. 21.

[0085] Fig. 22 shows the intervertebral implant 1 according to Fig. 21 with the upper contact bodies 10, 11 hidden but with the actuator 2 shown, in a perspective view from the distal side. Fig. 23 shows a cross-section through the intervertebral implant 1 with all contact bodies 10,

[0086] 11, 12, 13 in a proximal view. Since the intervertebral implant 1 has initially expanded only horizontally but not yet vertically, the contact bodies 11, 13 arranged on the left in Fig. 23 are laterally spaced from the contact bodies 10, 12 on the right, while the upper contact bodies 10, 11 are in contact with their respective vertically adjacent, here lower, contact bodies 12, 13. The vertical guide surfaces 23 of the proximal ramp body 7, as well as the vertical guide surfaces 23 of the distal ramp body 6, engage positively with the vertical counter-surfaces 29 of the contact bodies 10, 11, 12, 13; this prevents further horizontal expansion of the intervertebral implant 1.

[0087] In the transition from Fig. 19 to Fig. 24, the actuator 2 was further actuated. Fig. 25 shows the intervertebral implant 1 of Fig. 24 in a partial section. The ramp bodies 6, 7 are moved axially further towards each other. The vertical guide surfaces 23 of the ramp bodies 6, 7 are arranged in the cam guides 27, so that, in the course of the continued expansion movement, the contact bodies 10, 11, 12, 13 move vertically apart from each other. During this process, the vertical guide bodies 33 of the contact bodies 10, 11, 12, 13 move out of their associated vertical recesses 32. In this phase of the expansion movement, no lateral expansion of the intervertebral implant 1 takes place. As soon as the ramp bodies 6, 7 have moved axially towards each other to their maximum extent, the implant 1 is moved to its final position in Fig. 24.The 25 indicated threaded pin 36 of the contact body 12 is in contact with the associated proximal ramp body 7, so that further expansion movement of the intervertebral implant 1 is prevented. The intervertebral implant 1 has now assumed its maximally expanded position.

[0088] Figure 26 shows the vertically expanded intervertebral implant 1 in a cross-section at the level of the ramp body 7 in a perspective view from the distal side, similar to Figure 22. Due to the corresponding offset of the cross-sectional plane in the lower part of Figure 26 caused by the axial movement of the distal ramp body 6, the lateral guide body 30, which has partially moved out of the lateral recess 31, can be seen. This creates captive connections between the contact bodies 10, 11, 12, 13, irrevocable despite the expansion movement of the intervertebral implant 1. Figure 27 shows a cross-section through the intervertebral implant 1 at the level of the proximal ramp section 7 in a proximal view, with all contact bodies 10, 11, 12, 13 visible, so that the partial engagement of the upper lateral guide body 30 in the associated lateral recess 31 is also shown.Figures 28 to 31 show the expansion movement of the intervertebral implant 1 already explained, starting with the maximally compressed position of the intervertebral implant 1 in Fig. 28, through the exclusively lateral expansion movement of the contact bodies 10, 11, 12, 13 in Fig.

[0089] 29 up to the vertical expansion movement of the contact bodies 10, 11, 12, 13 in Fig. 30.

Claims

Patent claims 1. Intervertebral implant (1) with two upper contact bodies (10, 11) and with two lower contact bodies (12, 13), wherein the contact bodies (10, 11, 12, 13) each have at least one contact surface for contact with a vertebral body, wherein the intervertebral implant (1) has an actuator (2) with a threaded body (3) which is provided with two opposing threads (4, 5) arranged axially one behind the other, wherein the actuator (2) has two ramp bodies (6, 7) which are axially movable relative to the actuator (2) by a rotation of the actuator (2) about its longitudinal axis, wherein surfaces of the ramp bodies (6, 7) are in contact with surfaces of the contact bodies (10, 11, 12, 13), characterized in that the contact bodies (10, 11, 12, 13) are moved by an axial movement of the Ramp bodies (6, 7) can be expanded towards each other.

2. Intervertebral implant (1) according to claim 1, characterized in that the ramp bodies (6, 7) each have at least one vertical guide surface (23), wherein for each vertical guide surface (23) the contact body (10, 11, 12, 13) associated with the vertical guide surface (23) has a corresponding vertical counter surface (29) as a cam guide (27) into which the vertical guide surface (23) engages, wherein the vertical guide surfaces (23) of the ramp bodies (6, 7) during an axial movement of the The ramp bodies (6, 7) are movable in the scenery guides (27).

3. Intervertebral implant (1) according to claim 2, characterized in that at least one ramp body (6, 7) , in particular both ramp bodies (6, 7) , each have four vertical guide surfaces (23) which engage in the cam guides (27) of the four contact bodies (10, 11, 12, 13).

4. Intervertebral implant (1) according to one of claims 2 or 3, characterized in that the vertical guide surface (23) has an inclination about a lateral axis relative to the horizontal of non-zero°.

5. Intervertebral implant (1) according to one of claims 2 to 4, characterized in that the vertical guide surface (23) has at least one projection (21) which is trapezoidal in profile, in particular being provided that at least one recess (22) is arranged laterally adjacent to the projection.

6. Intervertebral implant (1) according to claim 5, characterized in that the projection (21) forms a right-angled trapezoid in profile, wherein in particular it is provided that its lateral inner leg (21a) is vertically oriented and / or wherein its lateral outer leg (21b) is vertically oriented outwards and laterally inwards.

7. Intervertebral implant (1) according to one of claims 5 or 6, characterized in that each vertical 37 The guide surface (23) has two laterally adjacent, trapezoidal projections (21) in profile, which are in particular identical to each other.

8. Intervertebral implant (1) according to one of claims 2 to 7, characterized in that the vertical guide surfaces (23) are arranged on the top (19) and on the bottom (20) of the ramp bodies (6, 7), in particular only on the top (19) and on the bottom (20) of the ramp bodies (6, 7).

9. Intervertebral implant (1) according to one of claims 2 to 8, characterized in that the vertical guide surface (23) has a guide projection (23a) arranged in particular in a corner region of the ramp body (6, 7), wherein it is particularly provided that all vertical guide surfaces (23) have a guide projection (23a) in each corner region of the ramp body (6, 7).

10. Intervertebral implant (1) according to one of claims 2 to 9, characterized in that the vertical guide surfaces (23) of the ramp bodies (6, 7) engage at least partially in a form-fitting manner in the cam guides (27) of the contact bodies (10, 11, 12, 13).

11. Intervertebral implant (1) according to one of claims 2 to 9, characterized in that the cam guide (27) of the contact body (10, 11, 12, 13) are arranged parallel to the vertical guide surface (23) of the ramp body (6, 7) associated with the contact body.

12. Intervertebral implant (1) according to one of claims 1 to 11, characterized in that the ramp bodies (6, 7) each have at least one lateral guide surface (15, 16, 17) for contact with a lateral counter surface (28) of the contact body (10, 11, 12, 13) associated with the ramp body (6, 7) which is designed corresponding to the lateral guide surface (15, 16, 17), wherein in particular the normal of the lateral guide surface (15, 16, 17) is arranged inclined relative to a lateral direction.

13. Intervertebral implant (1) according to claim 12, characterized in that the lateral counter surface (28) of the contact body (10, 11, 12, 13) is spaced apart from its axial end face and / or arranged axially in the region of the vertical counter surface (29).

14. Intervertebral implant (1) according to one of claims 1 to 13, characterized in that the actuator (2) has a particularly radially centered opening (9) which is designed in particular for the passage of a guide wire during movement of the intervertebral implant (1).

15. Intervertebral implant (1) according to one of claims 1 to 14, characterized in that the upper surface (19) and / or the lower surface (20) of the ramp body (6, 7), in particular its vertical guide surfaces (23), taper inwards in an axial direction, in particular linearly.

16. Intervertebral implant (1) according to one of claims 1 to 15, characterized in that at least one contact body (10, 11, 12, 13) has a vertical guide- a guide body (32) which is designed for a particularly sliding engagement in a vertical recess (33) of the contact body (10, 11, 12, 13) vertically adjacent to the contact body (10, 11, 12, 13) corresponding to the vertical guide body (32), and / or that at least one contact body (10, 11, 12, 13) has a lateral guide body (30) features a lateral recess designed to engage in a sliding manner, in particular, corresponding to the lateral guide body (30). (31) of the contact body (10, 11, 12, 13) which is laterally adjacent to the contact body (10, 11, 12, 13).

17. Intervertebral implant (1) according to one of claims 1 to 16, characterized in that at least one contact body (10, 11, 12, 13) has a locking mechanism (36) for the axial movement of the ramp body (6, 7) associated with the contact body (10, 11, 12, 13), wherein the locking mechanism (36) is in particular designed as a threaded pin (36) which can be screwed through a threaded recess (35) of the contact body (10, 11, 12, 13) and which is designed to limit the expansion movement of the intervertebral implant (1) when screwed in.

18. Intervertebral implant (1) according to one of claims 1 to 17, characterized in that the contact bodies (10, 11, 12, 13) are movable first laterally, in particular only laterally, and subsequently vertically, in particular only vertically, when the ramp bodies (6, 7) move axially towards each other.

19. Intervertebral implant (1) according to one of claims 1 to 18, characterized in that only a single actuator (2) is provided for the lateral expansion of the contact bodies (10, 11, 12, 13) and for the vertical expansion of the contact bodies (10, 11, 12, 13).

20. Intervertebral implant (1) according to one of claims 1 to 19, characterized in that the proximal end face (41) of the actuator (2) has a recess (42) for an expansion instrument in order to cause the axial movement of the ramp bodies (6, 7) towards each other and thereby cause the expansion movement of the contact bodies (10, 11, 12, 13).

21. Intervertebral implant (1) according to one of claims 1 to 20, characterized in that in the expanded state of the intervertebral implant (1) two vertically adjacent contact bodies (10, 11, 12, 13) on one lateral side have a distance to each other which is greater than the distance between the two vertically adjacent contact bodies (10, 11, 12, 13) on the other lateral side.

22. Intervertebral implant (1) according to one of claims 1 to 21, characterized in that in the expanded position of the intervertebral implant (1) at least one of the contact bodies (10, 11, 12, 13) is tilted relative to the compressed position of the intervertebral implant (1). 41

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