CN115844597B

CN115844597B - Elbow joint prosthesis

Info

Publication number: CN115844597B
Application number: CN202310181341.2A
Authority: CN
Inventors: 蒋协远; 查晔军; 公茂琪; 王亚松; 张帅
Original assignee: Beijing Jishuitan Hospital
Current assignee: Beijing AK Medical Co Ltd
Priority date: 2023-02-27
Filing date: 2023-02-27
Publication date: 2023-07-14
Anticipated expiration: 2043-02-27
Also published as: CN115844597A

Abstract

The present invention provides an elbow joint prosthesis comprising: the connecting block is provided with a first concave part on the upper surface and a second concave part on the lower surface; a humeral prosthesis comprising a humeral stem and a humeral head disposed at an end of the humeral stem, the humeral head being rotatably disposed within the first recess; the radius prosthesis comprises a radius handle and a radius ball head arranged at the end part of the radius handle, and the radius ball head is rotatably arranged in the second concave part; an ulna prosthesis detachably mounted on the lower surface of the connection block; a connecting structure disposed between the ulna prosthesis and the lower surface of the connecting block; wherein the ulna prosthesis is slidably mounted on the lower surface of the connection block by a connection structure. The technical scheme of the utility model effectively solves the problem that the humerus prosthesis and the ulna prosthesis in the related technology are hinged together, and then the position of the humerus prosthesis or the ulna prosthesis can not be independently regulated.

Description

Elbow joint prosthesis

Technical Field

The invention relates to the technical field of medical instruments, in particular to an elbow joint prosthesis.

Background

The elbow joint is composed of the lower end of the humerus, the upper ends of the ulna and the radius, and can do forward flexion and backward extension movements, and also participate in the pronation and supination movements of the forearm. When rheumatoid arthritis occurs in elbow joints, the elbow joints are involved, various joint diseases cause elbow joint dysfunction, congenital malformation of the elbow joints, old complicated osteoporosis distal humerus fracture and elbow joint related bone tumors, the conservative treatment cannot meet the basic requirements of patients. Therefore, total elbow joint replacement has become a major diagnostic and treatment for end-stage elbow joint pathology.

In the prior art, the humeral prosthesis and the ulna prosthesis are hinged together, so that the position of the ulna prosthesis cannot be independently adjusted or the position of the humeral prosthesis cannot be independently adjusted during implantation, which would affect the effect of implantation.

Disclosure of Invention

The main object of the present invention is to provide an elbow joint prosthesis, which solves the problem that the humerus prosthesis and the ulna prosthesis are hinged together in the related art, and thus the position of the humerus prosthesis or the ulna prosthesis cannot be independently adjusted.

To achieve the above object, the present invention provides an elbow joint prosthesis comprising: the connecting block is provided with a first concave part on the upper surface and a second concave part on the lower surface; a humeral prosthesis comprising a humeral stem and a humeral head disposed at an end of the humeral stem, the humeral head being rotatably disposed within the first recess; the radius prosthesis comprises a radius handle and a radius ball head arranged at the end part of the radius handle, and the radius ball head is rotatably arranged in the second concave part; an ulna prosthesis detachably mounted on the lower surface of the connection block; a connecting structure disposed between the ulna prosthesis and the lower surface of the connecting block; wherein the ulna prosthesis is slidably mounted on the lower surface of the connection block by a connection structure.

Further, the lower surface of the connection block includes a first region where the connection structure is disposed and a second region where the lower convex portion is disposed, and the second concave portion is disposed on the lower surface of the lower convex portion.

Further, the connecting block further comprises a limiting convex part arranged on the side wall of the lower convex part facing the connecting structure, the limiting convex part is arranged towards the protrusion of the ulna prosthesis, an accommodating space is formed between the limiting convex part and the first area, the ulna prosthesis comprises a platform part, the connecting structure is arranged between the first area and the platform part, and part of the structure of the platform part is positioned in the accommodating space.

Further, the connecting structure includes a runner and a slider, one of the runner and the slider being disposed in the first region, the other of the runner and the slider being disposed on the ulna prosthesis, an extending direction of the runner being perpendicular to a direction from the first region to the second region.

Further, a runner is provided in the first region, a slider is provided on an upper surface of the ulna prosthesis, a width of the runner gradually decreases in a direction from the humerus prosthesis to the ulna prosthesis, and a width of the slider gradually decreases.

Further, the spout includes first slot segment and second slot segment, and the lateral wall intercommunication of first slot segment first end and connecting block, the second end of first slot segment and the first end intercommunication of second slot segment, the second end of second slot segment are the blind end, and the second slot segment extends towards the direction of keeping away from the second concave part, and the slider can get into to the second slot segment from first slot segment.

Further, a retaining portion is disposed on a side of the second groove section away from the first groove section.

Further, the elbow joint prosthesis also comprises a pushing structure, wherein the pushing structure is arranged in the accommodating space and is matched with the platform part in a pushing way.

Further, the two ends of the accommodating space are provided with a first stop block and a second stop block, the push structure comprises a spring plate, the spring plate is bent and extruded between the first stop block and the second stop block, and the spring plate protrudes towards the platform part.

Further, a first baffle is arranged on the humerus handle, a space is reserved between the first baffle and the humerus head, and/or a second baffle is arranged on the radius handle, a space is reserved between the second baffle and the radius head, and/or the ulna prosthesis further comprises an ulna handle, the ulna handle is connected with the platform part, a third baffle is arranged on the ulna handle and is arranged at a space with the platform part, and/or when the axis of the radius handle is parallel to the axis of the ulna handle, the third baffle is arranged flush with the second baffle.

By applying the technical scheme of the invention, the connecting block is provided with the first concave part and the second concave part which are respectively arranged on the upper surface and the lower surface of the connecting block. The humeral prosthesis comprises a humeral stem and a humeral ball, the humeral ball is rotatably arranged in the first recess, the radius prosthesis comprises a radius stem and a radius ball, the radius ball is rotatably arranged in the second recess, the ulna prosthesis is detachably mounted on the lower surface of the connecting block, the connecting structure is arranged between the ulna prosthesis and the lower surface of the connecting block, and in particular, the ulna prosthesis can be slidably mounted on the lower surface of the connecting block through the connecting structure. Through the arrangement described above, the humeral prosthesis, the ulna prosthesis, the radius prosthesis and the connection block are divided into four separate parts and are all detachably connected, i.e. the humeral ball is detachably mounted in the first recess and the radius ball is detachably mounted in the second recess. Specifically, when the implantation is performed, the humerus stem is implanted into the humerus, the ulna prosthesis is implanted into the ulna, the radius stem is implanted into the radius, then the positions of the humerus prosthesis, the ulna prosthesis and the radius prosthesis are adjusted so that the positions meet the use requirements of patients, and finally the connecting block is installed among the humerus prosthesis, the ulna prosthesis and the radius prosthesis, so that the implantation is completed. Thus, the implantation effect can be ensured, and the assembly difficulty is low. Therefore, the technical scheme effectively solves the problem that the humerus prosthesis and the ulna prosthesis in the related technology are hinged together, and the position of the humerus prosthesis or the ulna prosthesis cannot be independently adjusted.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention. In the drawings:

fig. 1 shows a schematic perspective view of an embodiment of an elbow joint prosthesis according to the invention;

FIG. 2 shows a schematic exploded view of the elbow joint prosthesis of FIG. 1;

FIG. 3 shows a schematic cross-sectional view of the elbow joint prosthesis of FIG. 1;

fig. 4 shows a schematic perspective view of the humeral prosthesis of the elbow joint prosthesis of fig. 1;

FIG. 5 shows a schematic perspective view of the radius prosthesis of the elbow joint prosthesis of FIG. 1;

FIG. 6 shows a schematic perspective view of an ulna prosthesis of the elbow joint prosthesis of FIG. 1;

FIG. 7 shows a schematic perspective view of a connection block of the elbow joint prosthesis of FIG. 1;

FIG. 8 shows a schematic bottom view of the connection block of FIG. 7;

fig. 9 shows a schematic side view of the connection block of fig. 7.

Wherein the above figures include the following reference numerals:

10. a connecting block; 11. a first concave portion; 12. a second concave portion; 13. a first region; 14. a second region; 141. a lower protruding part; 15. a limit protrusion; 16. an accommodation space; 161. a first stopper; 162. a second stopper; 20. a humeral prosthesis; 21. humeral stem; 211. a first baffle; 22. humeral head; 30. a radius prosthesis; 31. radius handle; 311. a second baffle; 32. radius bulb; 40. an ulna prosthesis; 41. a platform part; 42. ulna stem; 421. a third baffle; 50. a connection structure; 51. a chute; 511. a first trough section; 512. a second trough section; 5121. a stopping portion; 52. a slide block; 60. a push structure; 61. a spring plate; 71. the first anti-rotation rib; 72. and a second anti-rotation rib.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the 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 in accordance with the present application. As used herein, the singular is also intended to include the plural unless the context clearly indicates otherwise, and furthermore, it is to be understood that the terms "comprises" and/or "comprising" when used in this specification are taken to specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof.

The relative arrangement of the components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless it is specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective parts shown in the drawings are not drawn in actual scale for convenience of description. Techniques, methods, and apparatus known to one of ordinary skill in the relevant art may not be discussed in detail.

As shown in fig. 1 to 3, in the present embodiment, the elbow joint prosthesis includes: the connecting block 10, the humeral prosthesis 20, the radial prosthesis 30, the ulna prosthesis 40, and the connecting structure 50. The connection block 10 is provided with a first recess 11 on an upper surface and a second recess 12 on a lower surface of the connection block 10. The humeral prosthesis 20 includes a humeral stem 21 and a humeral head 22 disposed at an end of the humeral stem 21, the humeral head 22 being rotatably disposed within the first recess 11. The radius prosthesis 30 includes a radius stem 31 and a radius ball 32 disposed at an end of the radius stem 31, the radius ball 32 being rotatably disposed in the second recess 12. Ulna prosthesis 40 an ulna prosthesis 40 is removably mounted on the lower surface of the connection block 10. The attachment structure 50 is disposed between the ulna prosthesis 40 and the inferior surface of the attachment block 10. Wherein the ulna prosthesis 40 is slidably mounted on the lower surface of the connection block 10 by means of a connection structure 50.

By applying the technical solution of the present embodiment, the connection block 10 is provided with a first recess 11 and a second recess 12, and the first recess 11 and the second recess 12 are respectively provided on the upper and lower surfaces of the connection block 10. The humeral prosthesis 20 includes a humeral stem 21 and a humeral head 22, the humeral head 22 is rotatably disposed within the first recess 11, the radius prosthesis 30 includes a radius stem 31 and a radius head 32, the radius head 32 is rotatably disposed within the second recess 12, the ulna prosthesis 40 is detachably mounted on the lower surface of the connection block 10, the connection structure 50 is disposed between the ulna prosthesis 40 and the lower surface of the connection block 10, and in particular, the ulna prosthesis 40 can be slidably mounted on the lower surface of the connection block 10 through the connection structure 50. With the above arrangement, the humeral prosthesis 20, the ulna prosthesis 40, the radius prosthesis 30 and the connection block 10 are divided into four separate parts and are all detachably connected, i.e., the humeral head 22 is detachably mounted in the first recess 11 and the radius head 32 is detachably mounted in the second recess 12. Specifically, at the time of implantation, the humerus stem 21 is implanted into the humerus, the ulna prosthesis 40 is implanted into the ulna, the radius stem 31 is implanted into the radius, then the positions of the humerus prosthesis 20, the ulna prosthesis 40 and the radius prosthesis 30 are adjusted so that they meet the use requirements of the patient, and finally the connection block 10 is installed between the humerus prosthesis 20, the ulna prosthesis 40 and the radius prosthesis 30, thereby completing the implantation. Thus, the implantation effect can be ensured, and the assembly difficulty is low. Therefore, the technical scheme of the embodiment effectively solves the problem that the humerus prosthesis and the ulna prosthesis in the related technology are hinged together, and the position of the humerus prosthesis or the ulna prosthesis cannot be independently adjusted.

As shown in fig. 1 to 3 and fig. 7 to 9, in the present embodiment, the lower surface of the connection block 10 includes a first region 13 and a second region 14, the connection structure 50 is provided at the first region 13, the second region 14 is provided with a lower convex portion 141, and the second concave portion 12 is provided on the lower surface of the lower convex portion 141. The above-mentioned division of the first region 13 and the second region 14 can avoid the interference or influence of the connection structure 50 and the second concave portion 12, and meanwhile, in order to further reduce the risk, a lower convex portion 141 is disposed at the second region 14, and the second concave portion 12 is disposed at the lower convex portion 141, so that a gap can be formed between the radius ball head 32 and the end portion of the ulna prosthesis 40, and further, the rotation of the radius ball head 32 is smoother, and meanwhile, interference with the ulna prosthesis 40 can be avoided.

Meanwhile, the thickness of the connecting block 10 can be increased by the arrangement of the lower protruding portion 141, so that the structural strength of the connecting block 10 is better.

As shown in fig. 1 to 3 and fig. 7 to 9, in the present embodiment, the connection block 10 further includes a limit protrusion 15 provided on a side wall of the lower protrusion 141 facing the connection structure 50, the limit protrusion 15 is convexly provided toward the ulna prosthesis 40, an accommodating space 16 is formed between the limit protrusion 15 and the first region 13, the ulna prosthesis 40 includes a platform portion 41, the connection structure 50 is provided between the first region 13 and the platform portion 41, and a part of the structure of the platform portion 41 is located in the accommodating space 16. The spacing convex part 15 has a simple structure, an accommodating space 16 is formed between the spacing convex part 15 and the first area 13, and a part of the structure of the platform part 41 can be inserted into the accommodating space 16 and clamped in the accommodating space 16, so that the separation of the ulna prosthesis 40 and the connecting block 10 can be avoided, and the stability of the ulna prosthesis 40 and the connecting block 10 after connection is better.

Preferably, the platform portion 41 is rectangular, so that the contact area between the side wall of the platform portion 41 and the side wall of the lower protrusion 141 is larger, and further, the stability of the platform portion 41 is better, and at the same time, the rotation stopping function can be achieved.

Specifically, in order to improve the structural strength of the limit projection 15, in the present embodiment, the limit projection 15 is of a plate-like structure, and of course, in an embodiment not shown in the drawings, limit projection positions are provided at intervals in a plurality of block-like structures.

Preferably, the length a of the limit projection 15 extending towards the first region 13 is equal to the minimum distance b between the limit projection 15 and the plane in which the first region 13 lies. In this way, the limiting effect on the platform 41 can be ensured, interference between the limiting convex part 15 and other structures is avoided, and meanwhile, the structural strength of the limiting convex part 15 can be improved.

Of course, the above advantages can be achieved as long as a and b satisfy the following relationship: a/b is more than or equal to 0.8 and less than or equal to 1.3.

As shown in fig. 1 to 3 and fig. 6 to 9, in the present embodiment, the connection structure 50 includes a runner 51 and a slider 52, one of the runner 51 and the slider 52 is provided in the first region 13, and the other of the runner 51 and the slider 52 is provided on the ulna prosthesis 40, and an extending direction of the runner 51 is perpendicular to a direction from the first region 13 to the second region 14. The sliding groove 51 and the sliding block 52 have simple structures, are convenient to set, and can effectively realize sliding connection. In particular, the direction of extension of the runner 51 is perpendicular to the direction from the first region 13 to the second region 14, which can avoid collision or interference between the ulna prosthesis 40 and the radius prosthesis 30 or affect the connection of the connection block 10 with the ulna prosthesis 40 and the radius prosthesis 30 when the ulna prosthesis 40 is assembled.

As shown in fig. 1 to 3 and fig. 6 to 9, in the present embodiment, the runner 51 is provided in the first region 13, the slider 52 is provided on the upper surface of the ulna prosthesis 40, the width of the runner 51 is gradually reduced in the direction from the humerus prosthesis 20 to the ulna prosthesis 40, and the width of the slider 52 is gradually reduced. The above arrangement can prevent the slide 52 from coming out of the slide groove 51, i.e., can further improve the stability of the connection of the ulna prosthesis 40 and the connection block 10. Specifically, in the present embodiment, the slider 52 has a tapered structure.

As shown in fig. 1 to 3 and fig. 6 to 9, in the present embodiment, the chute 51 includes a first slot section 511 and a second slot section 512, the first end of the first slot section 511 is communicated with the side wall of the connection block 10, the second end of the first slot section 511 is communicated with the first end of the second slot section 512, the second end of the second slot section 512 is a closed end, the second slot section 512 extends in a direction away from the second recess 12, and the slider 52 can enter the second slot section 512 from the first slot section 511. The first groove section 511 and the second groove section 512 are simple in structure and convenient to set, and particularly, the center line of the first groove section 511 is perpendicular to the center line of the second groove section 512. The slide 52 needs to slide from the first groove section 511 into the second groove section 512 with a turn, and when the slide 52 needs to be disengaged from the slide groove 51, the same needs to be turned. In an unmanned steering operation, it is difficult for the slider 52 to slide from the second groove section 512 into the first groove section 511. This ensures the stability of the connection.

As shown in fig. 1 to 3 and fig. 6 to 9, in the present embodiment, a retaining portion 5121 is disposed on a side of the second groove section 512 away from the first groove section 511. The provision of the stopper 5121 can further prevent the slide block 52 from being separated from the second slide groove 512, and further can further improve the stability of the position of the slide block 2. Specifically, the retaining portion 5121 includes a spaced rack structure with teeth that are inclined toward the second end of the second slot segment 512, which allows the slider 52 to slide easily into the second slot segment 512, but with greater difficulty from sliding out of the second slot segment 512. I.e. the tips of the teeth abut the slider 52.

As shown in fig. 1 to 3 and fig. 6 to 9, in the present embodiment, the elbow joint prosthesis further includes an ejector structure 60, and the ejector structure 60 is disposed in the accommodating space 16 and is in ejector-fit with the platform portion 41. The provision of the ejector structure 60 further ensures the position of the ulna prosthesis 40, i.e., the slider 52 is stably positioned in the second channel segment 512 and is not easily removed by the ejector structure 60.

As shown in fig. 1 to 3 and fig. 6 to 9, in the present embodiment, the two ends of the accommodating space 16 are provided with a first stop 161 and a second stop 162, the ejector structure 60 includes a spring 61, the spring 61 is bent and pressed between the first stop 161 and the second stop 162, and the spring 61 protrudes toward the platform 41. The above-mentioned elastic piece 61 has a simple structure, and the first stop block 161 and the second stop block 162 can limit the elastic piece, so that the elastic piece 61 is in a bent state, that is, the distance between the middle part of the elastic piece 61 and the side wall of the lower protruding part 141 is the largest. When the sliding block 52 on the platform part 41 slides into the first groove section 511, the extrusion force exerted by the elastic sheet 61 on the platform part 41 gradually increases, and when the sliding block 52 enters into the second end of the second groove section 512, the middle part of the elastic sheet 61 is abutted against the side wall of the platform part 41, so that the platform part 41 is difficult to move, namely, the sliding block 52 is difficult to move from the second groove section 512 into the first groove section 511, and the stability of the ulna prosthesis 40 is further ensured.

As shown in fig. 4, in this embodiment, the humerus stem 21 is provided with the first baffle 211, and an interval is provided between the first baffle 211 and the humerus head 22, so that the above arrangement can play a certain role in buffering, that is, avoid the humerus head 22 from contacting with the osteotomy surface of the humerus, and the first baffle 211 can be in abutting fit with the osteotomy surface of the humerus to prevent subsidence, so that the position of the humerus stem 21 is more stable.

As shown in fig. 5, in the present embodiment, a second baffle 311 is provided on the radius handle 31, with a space between the second baffle 311 and the radius ball 32, and the function of the second baffle 311 is the same as that of the first baffle 211.

As shown in fig. 6, in the present embodiment, the ulna prosthesis 40 further includes an ulna stem 42, the ulna stem 42 is connected to the platform 41, a third baffle 421 is provided on the ulna stem 42, the third baffle 421 and the platform 41 are provided at intervals, and the third baffle 421 and the second baffle 311 are provided flush when the axis of the radial stem 31 and the axis of the ulna stem 42 are parallel. The third shutter 421 functions the same as the first shutter 211. Meanwhile, when the axis of the radial stem 31 and the axis of the ulnar stem 42 are parallel, the third baffle 421 and the second baffle 311 are flush, so that the stability of the implantation position can be ensured, and the radial stem 31 and the ulnar stem 42 can be prevented from colliding.

The first baffle 211, the second baffle 311, and the third baffle 421 are all elliptical.

Specifically, as shown in fig. 4, in the present embodiment, the humerus stem 21 is a rectangular column with radian, is manufactured by using 3D printing technology, has a porous structure, and has a taper with the first baffle 211 as a starting position. The rectangular column can make the position of the humeral stem 21 more stable and not easily rotate.

As shown in fig. 4, in the present embodiment, the humeral head 22 is provided with a first connecting hole, and the humeral stem 21 includes a first connecting rod inserted into the first connecting hole, and the first connecting rod and the first connecting hole are adapted, specifically, the first connecting rod has a taper in a range of 5 ° 40'±5'.

As shown in fig. 5, in the present embodiment, the radius ball 32 is provided with a second connection hole, and the radius shank 31 includes a second connection rod inserted into the second connection hole, and the second connection rod and the second connection hole are adapted, specifically, the second connection rod has a taper in a range of 5 ° 40'±5'.

As shown in fig. 5 and 6, in the present embodiment, a plurality of first anti-rotation ribs 71 are provided on the ulnar stem 42. The radius shank 31 is provided with a plurality of second anti-rotation bars 72.

The technical scheme of the embodiment can completely replace the lower end of the humerus and the upper ends of the ulna and the radius, has the original motion function of the elbow joint, and realizes the purpose of repairing the elbow joint injury.

In the description of the present invention, it should be understood that the azimuth or positional relationships indicated by the azimuth terms such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal", and "top, bottom", etc., are generally based on the azimuth or positional relationships shown in the drawings, merely to facilitate description of the present invention and simplify the description, and these azimuth terms do not indicate and imply that the apparatus or elements referred to must have a specific azimuth or be constructed and operated in a specific azimuth, and thus should not be construed as limiting the scope of protection of the present invention; the orientation word "inner and outer" refers to inner and outer relative to the contour of the respective component itself.

Spatially relative terms, such as "above … …," "above … …," "upper surface at … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial location relative 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 in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "above" or "over" other devices or structures would then be oriented "below" or "beneath" the other devices or structures. Thus, the exemplary term "above … …" may include both orientations of "above … …" and "below … …". The device may also be positioned in other different ways (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

In addition, the terms "first", "second", etc. are used to define the components, and are only for convenience of distinguishing the corresponding components, and the terms have no special meaning unless otherwise stated, and therefore should not be construed as limiting the scope of the present invention.

The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An elbow joint prosthesis comprising:

a connecting block (10), wherein a first concave part (11) is arranged on the upper surface of the connecting block (10), and a second concave part (12) is arranged on the lower surface of the connecting block (10);

a humeral prosthesis (20) comprising a humeral stem (21) and a humeral head (22) provided at the end of the humeral stem (21), the humeral head (22) being rotatably provided within the first recess (11);

a radius prosthesis (30) comprising a radius shank (31) and a radius ball head (32) arranged at the end of the radius shank (31), wherein the radius ball head (32) is rotatably arranged in the second concave part (12);

an ulna prosthesis (40), the ulna prosthesis (40) being detachably mounted on a lower surface of the connection block (10);

a connecting structure (50) disposed between the ulna prosthesis (40) and the lower surface of the connecting block (10);

wherein the ulna prosthesis (40) is slidingly mounted on the lower surface of the connection block (10) by the connection structure (50).

2. Elbow joint prosthesis according to claim 1, wherein the lower surface of the connection block (10) comprises a first region (13) and a second region (14), the connection structure (50) being provided at the first region (13), the second region (14) being provided with a lower protrusion (141), the second recess (12) being provided on the lower surface of the lower protrusion (141).

3. Elbow joint prosthesis according to claim 2, wherein the connection block (10) further comprises a limit protrusion (15) provided on a side wall of the lower protrusion (141) facing the connection structure (50), the limit protrusion (15) protruding towards the ulna prosthesis (40), an accommodation space (16) is formed between the limit protrusion (15) and the first region (13), the ulna prosthesis (40) comprises a platform (41), the connection structure (50) is provided between the first region (13) and the platform (41), and a part of the structure of the platform (41) is located in the accommodation space (16).

4. Elbow prosthesis according to claim 2, wherein the connecting structure (50) comprises a runner (51) and a slider (52), one of the runner (51) and the slider (52) being arranged in the first region (13), the other of the runner (51) and the slider (52) being arranged on the ulnar prosthesis (40), the direction of extension of the runner (51) being perpendicular to the direction from the first region (13) to the second region (14).

5. Elbow joint prosthesis according to claim 4, wherein said runner (51) is provided in said first region (13), said slider (52) being provided on the upper surface of said ulna prosthesis (40), the width of said runner (51) gradually decreasing in the direction from said humeral prosthesis (20) to said ulna prosthesis (40), the width of said slider (52) gradually decreasing.

6. The elbow joint prosthesis according to claim 5, wherein the runner (51) comprises a first groove section (511) and a second groove section (512), the first end of the first groove section (511) is in communication with the side wall of the connecting block (10), the second end of the first groove section (511) is in communication with the first end of the second groove section (512), the second end of the second groove section (512) is a closed end, the second groove section (512) extends in a direction away from the second recess (12), and the slider (52) is capable of entering the second groove section (512) from the first groove section (511).

7. Elbow prosthesis according to claim 6, characterized in that the side of the second groove section (512) remote from the first groove section (511) is provided with a stop (5121).

8. An elbow joint prosthesis according to claim 3, further comprising an ejector structure (60), said ejector structure (60) being disposed within said receiving space (16) and being in ejector engagement with said platform portion (41).

9. The elbow joint prosthesis according to claim 8, wherein the accommodating space (16) is provided with a first stopper (161) and a second stopper (162) at both ends, the pushing structure (60) comprises a spring piece (61), the spring piece (61) is bent and pressed between the first stopper (161) and the second stopper (162), and the spring piece (61) protrudes toward the platform portion (41).

10. An elbow joint prosthesis according to claim 3, wherein a first baffle (211) is provided on the humeral stem (21), a space is provided between the first baffle (211) and the humeral head (22), and/or a second baffle (311) is provided on the radius stem (31), a space is provided between the second baffle (311) and the radius head (32), and/or the ulna prosthesis (40) further comprises an ulna stem (42), the ulna stem (42) is connected with the platform (41), a third baffle (421) is provided on the ulna stem (42), and the third baffle (421) is provided at a space from the platform (41).

11. An elbow joint prosthesis according to claim 3, wherein a second baffle (311) is provided on the radius stem (31), a space is provided between the second baffle (311) and the radius ball head (32), the ulna prosthesis (40) further comprises an ulna stem (42), the ulna stem (42) is connected with the platform (41), a third baffle (421) is provided on the ulna stem (42), the third baffle (421) is provided with the platform (41) at a distance, and when the axis of the radius stem (31) is parallel to the axis of the ulna stem (42), the third baffle (421) is provided with the second baffle (311) at a parallel.