CN112972073B

CN112972073B - Vertebral body prosthesis

Info

Publication number: CN112972073B
Application number: CN202110426997.7A
Authority: CN
Inventors: 王彩梅
Original assignee: Beijing AK Medical Co Ltd
Current assignee: Beijing AK Medical Co Ltd
Priority date: 2021-04-20
Filing date: 2021-04-20
Publication date: 2022-04-12
Anticipated expiration: 2041-04-20
Also published as: CN112972073A

Abstract

The invention provides a vertebral prosthesis, comprising: a first endplate; the first end of the connecting piece is connected with the first end plate in a swinging mode; a second end plate, which is connected to the second end of the connecting element in such a way that it can be displaced in the axial direction of the connecting element, so that the distance between the second end plate and the first end plate can be set in an adjustable manner. The technical scheme of the application effectively solves the problem that the matching of the end plate and the vertebral body of the human body in the related technology is poor, and then the implantation effect is influenced.

Description

Vertebral body prosthesis

Technical Field

The invention relates to the technical field of medical instruments, in particular to a vertebral body prosthesis.

Background

Patients with primary tumors of vertebral bodies of the spine, partial metastatic tumors, serious comminuted fractures of the vertebral bodies, serious explosive fissures of the spine and the like often need to perform vertebral body excision or secondary complete excision. The stability of the spine after removal of the vertebral body is undoubtedly impaired and reestablishing the structural function of the spine is a necessary condition for maintaining the normal biomechanical stability of the spine.

At present, the height-adjustable type can be divided into a fixed height type and an adjustable height type according to the structural difference.

The artificial vertebral body with the fixed height is the simplest and single type, only plays a certain supporting and fixing role in the operation, and is represented by a common titanium cage, a novel titanium cage, a 3D printing titanium cage and the like. The prosthesis of the type is lack of a height adjusting device, the height cannot be adjusted in time in the operation, most of self-stabilizing devices are conical spikes or sawtooth-shaped protrusions which are positioned on the end face of the prosthesis, sufficient stability is difficult to guarantee, and a titanium plate or a nail rod system is needed for assisting in fixing in the operation. The adjustable fixed artificial vertebral body is formed by adding a height adjusting device on a supporting fixed artificial vertebral body, and the device is mostly realized by relative sliding of an inner sleeve and an outer sleeve and takes a Synex artificial vertebral body, a novel expandable artificial vertebral body, a snake-brand hydro artificial vertebral body and the like as representatives.

However, the spine of a human body has physiological curvature, and the angle of the end plate of the existing product is always fixed, so that the end plate is poor in matching with the vertebral body of the human body, and the implantation effect is influenced.

Disclosure of Invention

The invention mainly aims to provide a vertebral body prosthesis, which aims to solve the problem that the matching of an end plate and a vertebral body of a human body in the related technology is poor, and the implantation effect is influenced.

In order to achieve the above object, the present invention provides a vertebral body prosthesis comprising: a first endplate; the first end of the connecting piece is connected with the first end plate in a swinging mode; a second end plate, which is connected to the second end of the connecting element in such a way that it can be displaced in the axial direction of the connecting element, so that the distance between the second end plate and the first end plate can be set in an adjustable manner.

Further, the connecting piece includes the pole body portion and sets up the spherical structure at the first end of pole body portion, spherical structure's diameter is greater than the diameter of pole body portion, first endplate includes first plate body and the first connecting portion of being connected with first plate body, be provided with on the first connecting portion and hold the chamber, spherical structure sets up in holding the intracavity, centrum prosthesis still includes first locking piece, first locking piece is connected on the pole body portion, first locking piece and the cooperation of first connecting portion butt, in order to lock the relative position between first connecting portion and the spherical structure.

Further, the lateral part of first connecting portion is provided with and supplies the spherical structure to get into to the mounting hole that holds the intracavity, all is provided with the breach of dodging the pole somatic part on the lateral part of first connecting portion and the bottom, and wherein, the mounting hole with dodge the breach all with hold the chamber intercommunication, the width of dodging the breach is less than the diameter of mounting hole.

Further, the rod body portion comprises a threaded section, the second end plate comprises a second plate body and a second connecting portion connected with the second plate body, a first threaded hole is formed in the second connecting portion, and the threaded section is in threaded connection with the first threaded hole.

Further, the vertebral body prosthesis further comprises a second locking piece, the second locking piece is connected to the rod body portion, and the second connecting portion is in butt fit with the second locking piece.

Furthermore, the first locking piece is provided with a second threaded hole, the first locking piece is in threaded connection with the threaded section in a matched mode, the second locking piece is provided with a third threaded hole, the second threaded hole and the third threaded hole are in threaded connection with the threaded section in a matched mode, a plurality of first grooves are arranged on the side wall of the first locking piece at intervals, and a plurality of second grooves are arranged on the side wall of the second locking piece at intervals.

Furthermore, a concave part is arranged on the top of the first locking part, and an arc-shaped part is arranged at the bottom of the first connecting part and is installed in the concave part.

Further, be provided with first bone grafting cabin on the first plate body, first bone grafting cabin includes first big footpath section and first path section, the outside of first big footpath section of first path section intercommunication and first plate body.

Further, be provided with the second on the second plate body and plant the bone cabin, the second is planted the bone cabin and is included second major diameter section and second path section, and second path section intercommunication second major diameter section and the outside of second plate body, second major diameter section and first screw hole intercommunication.

Further, the rod body part further comprises a connecting section, the connecting section is connected with the threaded section and the spherical structure, and the diameter of the connecting section is smaller than that of the threaded section.

Furthermore, one side of the first plate body facing the second plate body is provided with a first boss, one side of the second plate body facing the first plate body is provided with a second boss, and the surface of the first plate body away from the second plate body and the surface of the second plate body away from the first plate body are both arc-shaped surfaces.

By applying the technical scheme of the invention, the connecting piece is connected between the first end plate and the second end plate. The first end and the first end plate of connecting piece can be swung and be connected, through the swing of first end plate and connecting piece, can adjust the relative angle between first end plate and the connecting piece, make the centrum prosthesis can accord with the physiological curvature of human backbone like this, consequently the centrum prosthesis of this application can be better with human centrum cooperation, can improve patient's postoperative effect like this. Therefore, the technical scheme of the application effectively solves the problem that the matching of the end plate and the vertebral body of the human body in the related technology is poor, and the implantation effect is influenced. And moreover, the first end plate and the second end plate can be adjusted under the action of the connecting piece, namely, the distance between the first end plate and the second end plate is variable, so that the vertebral body prosthesis can be adapted to vertebral bodies of patients with different sizes, and the universality of the vertebral body prosthesis is better.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 shows a schematic front view of an embodiment of a vertebral body prosthesis according to the invention;

FIG. 2 shows a schematic side view of the vertebral prosthesis of FIG. 1;

FIG. 3 shows a schematic cross-sectional view of the vertebral prosthesis of FIG. 2;

FIG. 4 shows a perspective view of the vertebral prosthesis of FIG. 1;

FIG. 5 shows a perspective view of a partial structure of the vertebral prosthesis of FIG. 4;

FIG. 6 is a perspective view of a second endplate of the vertebral prosthesis of FIG. 4;

FIG. 7 illustrates a schematic elevational view of a first endplate of the vertebral prosthesis of FIG. 4;

FIG. 8 illustrates a cross-sectional view of the first endplate of FIG. 7;

FIG. 9 illustrates a perspective view of a second endplate of the vertebral prosthesis of FIG. 4;

FIG. 10 shows a perspective view of the second locking element of the vertebral prosthesis of FIG. 4;

FIG. 11 shows a cross-sectional schematic view of the secondary lock of FIG. 10; and

fig. 12 shows a schematic cross-sectional view of a first locking element of the vertebral prosthesis of fig. 4.

Wherein the figures include the following reference numerals:

10. a first endplate; 11. a first plate body; 111. a first bone grafting cabin; 112. a first boss; 1111. a first major diameter section; 1112. a first small diameter section; 12. a first connection portion; 121. an accommodating chamber; 122. mounting holes; 123. avoiding the notch; 124. an arc-shaped portion; 20. a connecting member; 21. a lever portion; 211. a threaded segment; 212. a connecting section; 22. a spherical structure; 30. a second endplate; 31. a second plate body; 311. a second bone grafting cabin; 312. a second boss; 3111. a second major diameter section; 3112. a second minor diameter section; 32. a second connecting portion; 321. a first threaded hole; 40. a first locking member; 41. a second threaded hole; 42. a first groove; 43. a recess; 50. a second locking member; 51. a third threaded hole; 52. a second groove.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

The relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail, but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

In the related art, the angle of the end plate of the vertebral prosthesis is fixed, but the spine of the human body has physiological curvature, in order to adapt to the physiological curvature of the spine of the human body, the bone of the end plate is scraped by a surgical file to change the cambered surface of the end plate to adapt to the vertebral prosthesis, so that the end plate is damaged, and the vertebral prosthesis sinks.

In order to solve the above-mentioned problems, as shown in fig. 1 to 5, in the present embodiment, the vertebral body prosthesis comprises: a first endplate 10, a connector 20, and a second endplate 30. The first end of the connecting element 20 is connected to the first closure plate 10 in a pivoting manner. The second end plate 30 is connected to the second end of the connecting element 20 so as to be displaceable in the axial direction of the connecting element 20, so that the distance between the second end plate 30 and the first end plate 10 can be set adjustably.

With the solution according to the present exemplary embodiment, the connecting element 20 is connected between the first end plate 10 and the second end plate 30. The first end of the connecting piece 20 is connected with the first end plate 10 in a swinging mode, and the relative angle between the first end plate 10 and the connecting piece 20 can be adjusted through the swinging of the first end plate 10 and the connecting piece 20, so that the vertebral body prosthesis can accord with the physiological curvature of the spine of a human body, and therefore the vertebral body prosthesis can be better matched with the vertebral body of the human body, and the postoperative effect of a patient can be improved. Therefore, the technical scheme of the embodiment effectively solves the problem that the matching of the end plate and the vertebral body of the human body in the related technology is poor, and the implantation effect is influenced. Moreover, the first end plate 10 and the second end plate 30 can be adjusted under the action of the connecting piece 20, namely, the distance between the first end plate 10 and the second end plate 30 can be adjusted, so that the vertebral body prosthesis of the embodiment can be adapted to the vertebral bodies of patients with different sizes. Thereby making the vertebral body prosthesis of the embodiment more versatile.

In an embodiment not shown in the figures, the first connecting portion is a split structure, the spherical structure is mounted in the accommodating cavity, and the split structures are connected together.

In order to effectively realize the swinging between the connecting member and the first end plate, as shown in fig. 1 to 5 and 9, in this embodiment, the connecting member 20 includes a rod body portion 21 and a spherical structure 22 disposed at a first end of the rod body portion 21, a diameter of the spherical structure 22 is greater than a diameter of the rod body portion 21, the first end plate 10 includes a first plate body 11 and a first connecting portion 12 connected to the first plate body 11, a receiving cavity 121 is disposed on the first connecting portion 12, the spherical structure 22 is disposed in the receiving cavity 121, the vertebral prosthesis further includes a first locking member 40, the first locking member 40 is connected to the rod body portion 21, the first locking member 40 is in abutting fit with the first connecting portion 12 to lock a relative position between the first connecting portion 12 and the spherical structure 22. The spherical structure 22 is simple in structure and easy to machine, the spherical structure 22 is mounted in the receiving cavity 121, and the spherical structure 22 can rotate in the receiving cavity 121, i.e., the connecting element 20 can swing relative to the first endplate 10, so that the vertebral body prosthesis can adapt to the physiological curvature of the spine of the human body. The first locking member 40 can lock the position of the first end plate 10, and the position of the first end plate 10, that is, the angle between the first end plate 10 and the connecting member 20 can be ensured by the first locking member 40.

It should be noted that the above-mentioned swinging means that the first end plate 10 swings in a plane relative to the connecting member 20 when the first locking member 40 is installed. When the first locking member 40 is not installed, the first endplate 10 is capable of 360 rotation relative to the first plane.

In order to facilitate the installation of the spherical structure, as shown in fig. 1 to 8, in the present embodiment, the side portion of the first connecting portion 12 is provided with an installation hole 122 for the spherical structure 22 to enter into the accommodating cavity 121, and the side portion and the bottom portion of the first connecting portion 12 are provided with an avoiding notch 123 for avoiding the rod body portion 21, wherein the installation hole 122 and the avoiding notch 123 are both communicated with the accommodating cavity 121, and the width of the avoiding notch 123 is smaller than the diameter of the installation hole 122. The mounting hole 122 is provided to facilitate mounting of the ball 22, and the relief 123 allows the connector 20 to be swung under the first endplate 10. To avoid the spherical structure 22 from falling out, the relief notch 123 is sized smaller than the bore diameter of the mounting hole 122.

In order to adjust the distance between the first end plate and the second end plate, as shown in fig. 1 to 5 and 9, in the present embodiment, the rod body portion 21 includes a threaded section 211, the second end plate 30 includes a second plate body 31 and a second connection portion 32 connected to the second plate body 31, a first threaded hole 321 is provided on the second connection portion 32, and the threaded section 211 and the first threaded hole 321 are in threaded connection. The threaded connection mode is simple, the rod body part 21 and the second end plate 30 can be effectively connected through the threaded structure, and the second end plate 30 can move up and down relative to the connecting piece 20 under the action of the threaded section 211 and the first threaded hole 321, so that the whole height of the vertebral body prosthesis can be changed.

In view of the problem of fixing the position of the second end plate, as shown in fig. 1 to 5 and fig. 10 and 11, in this embodiment, the vertebral body prosthesis further comprises a second locking member 50, the second locking member 50 is connected to the rod body portion 21, and the second connecting portion 32 and the second locking member 50 are in abutting engagement. The provision of the second locking element 50 effectively locks the position of the second connection 32, i.e. the position of the second end plate 30. The second locking member 50 prevents the threaded structure from disengaging due to the threaded connection between the second end plate 30 and the connector 20.

In order to fix the first end plate, as shown in fig. 1 to 4 and 12, in the present embodiment, the first locking member 40 has a second threaded hole 41, the first locking member 40 is threadedly engaged with the threaded section 211, the second locking member 50 has a third threaded hole 51, both the second threaded hole 41 and the third threaded hole 51 are threadedly engaged with the threaded section 211, a plurality of first grooves 42 are provided at intervals on a sidewall of the first locking member 40, and a plurality of second grooves 52 are provided at intervals on a sidewall of the second locking member 50. The threaded engagement of the first locking member 40 and the threaded section 211 and the threaded engagement of the second locking member 50 and the threaded section 211 are simple and easy to implement. The first and

second grooves

42 and 52 are provided to facilitate the application of force to the first and

second locking members

40 and 50, which results in better locking of the first and

second locking members

40 and 50.

In an embodiment not shown in the figures, the first and second locking members may also effect locking of the first and second end plates by means of a latch-type structure. Or the first locking piece and the second locking piece are fixed on the rod body part in an adhesive way.

In order to improve the fixing effect of the first endplate, as shown in fig. 1 to 4 and 12, in the present embodiment, a concave portion 43 is disposed on the top of the first locking member 40, the bottom of the first connecting portion 12 has an arc-shaped portion 124, and the arc-shaped portion 124 is installed in the concave portion 43. The arcuate portion 124 is adapted to fit into the recess 43, which stabilizes the position of the first endplate 10.

In order to improve the overall fixation effect of the vertebral body prosthesis, as shown in fig. 3, 4 and 8, in the present embodiment, the first plate body 11 is provided with the first bone grafting compartment 111, the first bone grafting compartment 111 includes a first large-diameter section 1111 and a first small-diameter section 1112, and the first small-diameter section 1112 is communicated with the first large-diameter section 1111 and the outside of the first plate body 11. Human bone or bone allograft is placed in the first bone grafting compartment 111, so that biological fixation can be effectively realized. And because first major diameter section 1111 is located the below of first minor diameter section 1112, like this when autologous bone structure grow into first bone grafting cabin 111 in, can enter into first major diameter section 1111 by first minor diameter section 1112, can improve fixed effect like this effectively.

As shown in fig. 3, 4 and 8, in the present embodiment, the second plate 31 is provided with a second bone grafting compartment 311, the second bone grafting compartment 311 includes a second major diameter section 3111 and a second minor diameter section 3112, the second minor diameter section 3112 communicates with the second major diameter section 3111 and the outside of the second plate 31, and the second major diameter section 3111 communicates with the first threaded hole 321. The effect that the bone cabin 311 was planted to the second is similar with the effect that first bone cabin 111 was planted, and the difference is that second major diameter section 3111 communicates with first screw hole 321, and is good at the long back of going into to second bone cabin 311 of planting of autologous bone structure like this, can with body of rod portion 21 butt, can further guarantee body of rod portion 21's position like this, avoid body of rod portion 21 atress too big and lead to its dropout, influence patient's implantation effect.

To facilitate the installation of the first end plate and the connecting member, as shown in fig. 1 to 5 and 9, in this embodiment, the rod portion 21 further includes a connecting section 212, the connecting section 212 connects the threaded section 211 and the spherical structure 22, and the diameter of the connecting section 212 is smaller than that of the threaded section 211. The connecting segment 212 can effectively pass through the relief opening 123, which can facilitate the swinging of the shaft portion 21 under the first end plate 10.

In order to improve the structural strength of the first connecting portion and the second connecting portion, as shown in fig. 1 to 8, in this embodiment, a first boss 112 is disposed on one side of the first plate 11 facing the second plate 31, a second boss 312 is disposed on one side of the second plate 31 facing the first plate 11, and both a surface of the first plate 11 away from the second plate 31 and a surface of the second plate 31 away from the first plate 11 are arc surfaces. The arrangement of the first bosses 112 and the second bosses 312 can effectively improve the structural strength of the first connecting portion 12 and the second connecting portion 32, and prevent the first connecting portion and the second connecting portion from being damaged. The arc-shaped surface can be effectively matched with the vertebral body of a human body.

In the description of the present invention, it is to be understood that the orientation or positional relationship indicated by the orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal" and "top, bottom", etc. are usually based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplicity of description, and in the case of not making a reverse description, these orientation words do not indicate and imply that the device or element being referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore, should not be considered as limiting the scope of the present invention; the terms "inner and outer" refer to the inner and outer relative to the profile of the respective component itself.

Spatially relative terms, such as "above … …," "above … …," "above … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial relationship to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, devices described as "above" or "on" other devices or configurations would then be oriented "below" or "under" the other devices or configurations. Thus, the exemplary term "above … …" can include both an orientation of "above … …" and "below … …". The device may be otherwise variously oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

It should be noted that the terms "first", "second", and the like are used to define the components, and are only used for convenience of distinguishing the corresponding components, and the terms have no special meanings unless otherwise stated, and therefore, the scope of the present invention should not be construed as being limited.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A vertebral prosthesis, comprising:

a first endplate (10);

a connecting element (20), a first end of the connecting element (20) being connected to the first closure plate (10) in a pivoting manner;

a second end plate (30) which is connected to the second end of the connecting piece (20) so as to be movable in the axial direction of the connecting piece (20) such that the distance between the second end plate (30) and the first end plate (10) can be set in an adjustable manner;

the connecting piece (20) comprises a rod body part (21) and a spherical structure (22) arranged at the first end of the rod body part (21), the diameter of the spherical structure (22) is larger than that of the rod body part (21), the first end plate (10) comprises a first plate body (11) and a first connecting part (12) connected with the first plate body (11), a containing cavity (121) is arranged on the first connecting part (12), and the spherical structure (22) is arranged in the containing cavity (121); the shank portion (21) comprises a threaded section (211);

the vertebral body prosthesis further comprises a first locking piece (40), the first locking piece (40) is connected to the rod body portion (21), the first locking piece (40) is in butt fit with the first connecting portion (12) to lock the relative position between the first connecting portion (12) and the spherical structure (22), the first locking piece (40) is provided with a second threaded hole (41), and the first locking piece (40) is in threaded fit with the threaded section (211).

2. Vertebral body prosthesis according to claim 1, characterized in that the side of the first connection portion (12) is provided with a mounting hole (122) for the spherical structure (22) to enter into the accommodation cavity (121), and the side and the bottom of the first connection portion (12) are provided with an avoidance notch (123) for avoiding the rod portion (21), wherein the mounting hole (122) and the avoidance notch (123) are both communicated with the accommodation cavity (121), and the width of the avoidance notch (123) is smaller than the diameter of the mounting hole (122).

3. Vertebral prosthesis according to claim 1, characterized in that said second endplate (30) comprises a second plate (31) and a second connection portion (32) connected to said second plate (31), said second connection portion (32) being provided with a first threaded hole (321), said threaded section (211) being in threaded connection with said first threaded hole (321).

4. Vertebral prosthesis according to claim 3, characterized in that it further comprises a second locking element (50), said second locking element (50) being connected to said stem portion (21), said second connection portion (32) and said second locking element (50) being in abutting engagement.

5. The vertebral prosthesis according to claim 4, characterized in that said second locking element (50) has a third threaded hole (51), said second threaded hole (41) and said third threaded hole (51) are both threadedly engaged with said threaded section (211), said first locking element (40) has a plurality of first grooves (42) spaced apart from each other on a side wall thereof, and said second locking element (50) has a plurality of second grooves (52) spaced apart from each other on a side wall thereof.

6. Vertebral body prosthesis according to claim 3, characterized in that a recess (43) is provided on the top of the first locking element (40), and in that the bottom of the first connection portion (12) has an arc-shaped portion (124), the arc-shaped portion (124) fitting into the recess (43).

7. The vertebral prosthesis according to claim 1, characterized in that a first bone graft compartment (111) is provided on said first plate body (11), said first bone graft compartment (111) comprising a first large diameter section (1111) and a first small diameter section (1112), said first small diameter section (1112) communicating said first large diameter section (1111) and the exterior of said first plate body (11).

8. The vertebral prosthesis according to claim 3, characterized in that a second bone graft compartment (311) is provided on said second plate (31), said second bone graft compartment (311) comprising a second large diameter section (3111) and a second small diameter section (3112), said second small diameter section (3112) communicating said second large diameter section (3111) with the outside of said second plate (31), said second large diameter section (3111) communicating with said first threaded hole (321).

9. The vertebral body prosthesis according to claim 3, wherein the stem portion (21) further comprises a connecting section (212), the connecting section (212) connecting the threaded section (211) and the spherical structure (22), the connecting section (212) having a diameter smaller than the diameter of the threaded section (211).

10. Vertebral prosthesis according to claim 3, characterized in that the side of the first plate (11) facing the second plate (31) is provided with a first boss (112), the side of the second plate (31) facing the first plate (11) is provided with a second boss (312), the surface of the first plate (11) facing away from the second plate (31) and the surface of the second plate (31) facing away from the first plate (11) are both arc-shaped surfaces.