CN115844597A

CN115844597A - Elbow joint prosthesis

Info

Publication number: CN115844597A
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: 2023-03-28
Anticipated expiration: 2043-02-27
Also published as: CN115844597B

Abstract

The invention provides an elbow joint prosthesis, comprising: the upper surface of the connecting block is provided with a first concave part, and the lower surface of the connecting block is provided with a second concave part; the humerus prosthesis comprises a humerus handle and a humerus ball head arranged at the end part of the humerus handle, and the humerus ball head is rotatably arranged in the first concave part; 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; the ulna prosthesis is detachably arranged 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; wherein, the ulna prosthesis is arranged on the lower surface of the connecting block in a sliding way through the connecting structure. The technical scheme of this application has solved the humerus prosthesis among the relevant art effectively and has articulated together with ulna prosthesis, and then can't adjust the problem of humerus prosthesis or ulna prosthesis's position alone.

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 end of the ulna and the radius, and can do anteflexion and postextension movements and also participate in the pronation and supination movements of the forearm. When the elbow joint has the symptoms of rheumatoid arthritis affecting the elbow joint, elbow joint dysfunction caused by various arthropathy, elbow joint congenital malformation, old complex osteoporotic distal humeral fracture and elbow joint related bone tumor, the basic requirements of patients cannot be met by conservative treatment. Therefore, total elbow joint replacement has become the main diagnosis and treatment mode of the final stage elbow joint disease.

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

Disclosure of Invention

The invention mainly aims to provide an elbow joint prosthesis, which solves the problem that the position of a humerus prosthesis or an ulna prosthesis cannot be independently adjusted because a humerus prosthesis and the ulna prosthesis are hinged together in the related art.

In order to achieve the above object, the present invention provides an elbow joint prosthesis comprising: the upper surface of the connecting block is provided with a first concave part, and the lower surface of the connecting block is provided with a second concave part; the humerus prosthesis comprises a humerus handle and a humerus ball head arranged at the end part of the humerus handle, and the humerus ball head is rotatably arranged in the first concave part; 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; the ulna prosthesis is detachably arranged on the lower surface of the connecting block; the connecting structure is arranged between the ulnar prosthesis and the lower surface of the connecting block; wherein, the ulna prosthesis is arranged on the lower surface of the connecting block in a sliding way through the connecting structure.

Further, the lower surface of the connecting block comprises a first area and a second area, the connecting structure is arranged in the first area, a lower convex part is arranged at the second area, and a second concave part is arranged on the lower surface of the lower convex part.

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

Further, the connecting structure comprises a sliding groove and a sliding block, one of the sliding groove and the sliding block is arranged in the first area, the other of the sliding groove and the sliding block is arranged on the ulnar prosthesis, and the extending direction of the sliding groove is perpendicular to the direction from the first area to the second area.

Further, the sliding groove is arranged in the first area, the sliding block is arranged on the upper surface of the ulna prosthesis, the width of the sliding groove is gradually reduced in the direction from the humerus prosthesis to the ulna prosthesis, and the width of the sliding block is gradually reduced.

Further, the spout includes first groove section and second groove section, the lateral wall intercommunication of the first end of first groove section and connecting block, the second end of first groove section and the first end intercommunication of second groove section, the second end of second groove section is the blind end, the second groove section orientation is kept away from the direction extension of second concave part, the slider can enter into the second groove section from first groove section.

Furthermore, one side of the second groove section, which is far away from the first groove section, is provided with a backstop part.

Further, the elbow joint prosthesis further comprises an ejecting structure, and the ejecting structure is arranged in the accommodating space and matched with the platform portion in an ejecting mode.

Further, accommodation space's both ends are provided with first dog and second dog, and ejection structure includes the shell fragment, and the shell fragment is buckled and is extruded between first dog and second dog, and the shell fragment is convex towards platform portion.

Further, a first baffle is arranged on the humerus handle, a gap is formed between the first baffle and the humerus ball head, and/or a second baffle is arranged on the radius handle, a gap is formed between the second baffle and the radius ball 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, the third baffle and the platform part are arranged at intervals, and/or when the axis of the radius handle is parallel to the axis of the ulna handle, the third baffle and the second baffle are arranged in an aligning mode.

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 humerus prosthesis comprises a humerus handle and a humerus ball head, the humerus ball head is rotatably arranged in the first concave portion, the radius prosthesis comprises a radius handle and a radius ball head, the radius ball head is rotatably arranged in the second concave portion, 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 specifically, the ulna prosthesis can be slidably mounted on the lower surface of the connecting block through the connecting structure. Through foretell setting, humerus prosthesis, ulna prosthesis, radius prosthesis and connecting block divide into four solitary parts, and are detachably connected, and humerus bulb detachably installs in first concave part promptly, and radius bulb detachably installs in the second concave part. Specifically, when the humerus prosthesis, the ulna prosthesis and the radius prosthesis are implanted into the humerus, the ulna prosthesis and the radius handle are implanted into the radius, the positions of the humerus prosthesis, the ulna prosthesis and the radius prosthesis are adjusted to meet the use requirements of a patient, and finally the connecting block is installed among the humerus prosthesis, the ulna prosthesis and the radius prosthesis, so that the implantation is completed. Therefore, the implantation effect can be ensured, and the assembly difficulty is lower. Therefore, the technical scheme of the application 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 cannot be independently adjusted.

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:

figure 1 shows a perspective view of an embodiment of an elbow prosthesis according to the invention;

figure 2 shows an exploded schematic view of the elbow prosthesis of figure 1;

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

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

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

FIG. 6 shows a perspective view of an ulnar prosthesis of the elbow prosthesis of FIG. 1;

figure 7 shows a schematic perspective view of a connection block of the elbow prosthesis of figure 1;

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

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

Wherein the figures include the following reference numerals:

10. connecting blocks; 11. a first recess; 12. a second recess; 13. a first region; 14. a second region; 141. a lower convex portion; 15. a limiting convex part; 16. an accommodating space; 161. a first stopper; 162. a second stopper; 20. a humerus prosthesis; 21. a humeral stem; 211. a first baffle plate; 22. a humeral head; 30. a radius prosthesis; 31. a radius stem; 311. a second baffle; 32. the head of the radius; 40. an ulna prosthesis; 41. a platform part; 42. a ulna stem; 421. a third baffle plate; 50. a connecting structure; 51. a chute; 511. a first groove section; 512. a second groove section; 5121. a backstop section; 52. a slider; 60. a pushing structure; 61. a spring plate; 71. a first anti-rotation rib; 72. the second prevents changeing the muscle.

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 exemplary 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.

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

With the solution of the present embodiment, the connecting block 10 is provided with a first concave portion 11 and a second concave portion 12, and the first concave portion 11 and the second concave portion 12 are respectively disposed on the upper surface and the lower surface of the connecting block 10. The humeral prosthesis 20 includes a humeral stem 21 and a humeral ball head 22, the humeral ball head 22 is rotatably disposed in the first recess 11, the radius prosthesis 30 includes a radius stem 31 and a radius ball head 32, the radius ball head 32 is rotatably disposed in the second recess 12, the ulnar prosthesis 40 is detachably mounted on the lower surface of the connection block 10, a connection structure 50 is disposed between the ulnar prosthesis 40 and the lower surface of the connection block 10, and specifically, the ulnar 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 ulnar prosthesis 40, the radial prosthesis 30, and the attachment block 10 are divided into four separate parts, and are all detachably attached, i.e., the humeral ball head 22 is detachably mounted in the first recess 11, and the radius ball head 32 is detachably mounted in the second recess 12. Specifically, when the humerus stem 21, the ulna prosthesis 40, and the radius stem 31 are implanted into humerus and radius respectively, the positions of the humerus prosthesis 20, the ulna prosthesis 40, and the radius prosthesis 30 are adjusted so as to 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. Therefore, the implantation effect can be ensured, and the assembly difficulty is lower. Therefore, the technical scheme of the embodiment effectively solves the problem that the humerus prosthesis and the ulna prosthesis in the related art 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 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 disposed at the first region 13, the second region 14 is provided with a lower convex portion 141, and the second concave portion 12 is disposed on the lower surface of the lower convex portion 141. The division of the first region 13 and the second region 14 can avoid the interference or influence of the connecting structure 50 and the second concave portion 12, and meanwhile, in order to further reduce the risk, the lower convex portion 141 is arranged at the second region 14, and the second concave portion 12 is arranged at the lower convex portion 141, so that a gap can be formed between the radius ball head 32 and the end of the ulnar prosthesis 40, the rotation of the radius ball head 32 is smoother, and the interference with the ulnar prosthesis 40 can be avoided.

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

As shown in fig. 1 to 3 and 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 provided to protrude toward the ulnar prosthesis 40, an accommodating space 16 is formed between the limit protrusion 15 and the first region 13, the ulnar prosthesis 40 includes a platform 41, the connection structure 50 is provided between the first region 13 and the platform 41, and a part of the platform 41 is located in the accommodating space 16. The limiting convex part 15 is simple in structure, the accommodating space 16 is formed between the limiting convex part 15 and the first area 13, 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 ulnar prosthesis 40 and the connecting block 10 can be prevented from being separated, and the stability of the ulnar prosthesis 40 and the connecting block 10 after connection is better.

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

Specifically, in order to improve the structural strength of the convex stopper portion 15, the convex stopper portion 15 is a plate-like structure in the present embodiment, but of course, in an embodiment not shown in the drawings, the convex stopper portion is provided at intervals in a plurality of block-like structures.

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

Of course, both a and b can achieve the above-described advantages as long as they satisfy the following relationships: 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 6 to 9, in the present embodiment, the connecting structure 50 includes a slide groove 51 and a slider 52, one of the slide groove 51 and the slider 52 is disposed in the first region 13, the other of the slide groove 51 and the slider 52 is disposed on the ulnar prosthesis 40, and the extending direction of the slide groove 51 is perpendicular to the direction from the first region 13 to the second region 14. The sliding grooves 51 and the sliding blocks 52 have simple structures, are convenient to arrange, and can effectively realize sliding connection. Specifically, the sliding groove 51 extends in a direction perpendicular to the direction from the first region 13 to the second region 14, so that it is possible to avoid collision or interference between the ulnar prosthesis 40 and the radial prosthesis 30 or interference with the connection block 10 connected to the ulnar prosthesis 40 and the radial prosthesis 30 when the ulnar prosthesis 40 is assembled.

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

As shown in fig. 1 to 3 and 6 to 9, in the present embodiment, the sliding groove 51 includes a first groove section 511 and a second groove section 512, a first end of the first groove section 511 communicates with a side wall of the connecting block 10, a second end of the first groove section 511 communicates with a first end of the second groove section 512, a 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 can enter from the first groove section 511 to the second groove section 512. The first slot segment 511 and the second slot segment 512 are simple in structure and easy to set, and particularly, the center line of the first slot segment 511 is perpendicular to the center line of the second slot segment 512. The slide 52 needs to slide from the first slot segment 511 into the second slot segment 512 via a turn, which is also needed when the slide 52 needs to be disengaged from the slide slot 51. In the absence of a manual steering operation, the slider 52 is difficult to slide from the second slot segment 512 into the first slot segment 511. This ensures the stability of the connection.

As shown in fig. 1 to 3 and 6 to 9, in the present embodiment, a retaining portion 5121 is disposed on a side of the second slot segment 512 away from the first slot segment 511. The provision of the retaining portion 5121 can further prevent the slider 52 from being disengaged from the second chute 512, and further improve the positional stability of the slider 2. Specifically, the backstop 5121 includes a spaced rack structure, and the teeth of the rack structure are inclined toward the second end of the second slot segment 512, so that the slider 52 can easily slide into the second slot segment 512, but the difficulty of sliding out of the second slot segment 512 is greater. I.e. the tip of the lobe abuts 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 60, and the ejector 60 is disposed in the receiving space 16 and is in ejector engagement with the platform 41. The arrangement of the pushing structure 60 can further ensure the position of the ulnar prosthesis 40, that is, the sliding block 52 can be stably positioned in the second groove section 512 and is not easy to fall out under the action of the pushing structure 60.

As shown in fig. 1 to 3 and fig. 6 to 9, in the present embodiment, a first stopper 161 and a second stopper 162 are disposed at two ends of the accommodating space 16, the pushing structure 60 includes 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. The elastic sheet 61 is simple in structure, the first stopper 161 and the second stopper 162 can limit the elastic sheet, and the elastic sheet 61 is in a bent state, namely, the distance between the middle of the elastic sheet 61 and the side wall of the lower convex portion 141 is the largest. When the sliding block 52 on the platform part 41 slides to the first groove section 511, the force of the pressing applied to the platform part 41 by the elastic sheet 61 is gradually increased, and when the sliding block 52 enters the second end of the second groove section 512, the middle part of the elastic sheet 61 is abutted to 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 to the first groove section 511, and the stability of the ulnar prosthesis 40 is further ensured.

As shown in fig. 4, in the present embodiment, the first baffle 211 is disposed on the humeral stem 21, and a space is provided between the first baffle 211 and the humeral head 22, the above arrangement can play a certain buffering role, i.e. the humeral head 22 and the humeral osteotomy surface are prevented from contacting each other, and the first baffle 211 can be abutted and matched with the osteotomy surface on the humeral to prevent subsidence, so as to further stabilize the position of the humeral stem 21.

As shown in fig. 5, in the present embodiment, a second baffle 311 is provided on the radius shaft 31, a space is provided between the second baffle 311 and the radius bulb 32, and the second baffle 311 has the same function as the first baffle 211.

As shown in fig. 6, in the present embodiment, the ulnar prosthesis 40 further includes an ulnar stem 42, the ulnar stem 42 is connected to the platform portion 41, a third baffle 421 is provided on the ulnar stem 42, the third baffle 421 is spaced from the platform portion 41, and when the axis of the radius stem 31 is parallel to the axis of the ulnar stem 42, the third baffle 421 and the second baffle 311 are flush with each other. The third shutter 421 has the same function as the first shutter 211. Meanwhile, when the axis of the radius shaft 31 and the axis of the ulna shaft 42 are parallel, the third baffle 421 and the second baffle 311 are arranged in parallel, so that the stability of implantation to the position can be ensured, and the collision between the radius shaft 31 and the ulna shaft 42 can be avoided.

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

Specifically, as shown in fig. 4, in the present embodiment, the humeral stem 21 is a rectangular cylinder with a curvature, is manufactured by a 3D printing technique, has a porous structure, and is tapered with the first baffle 211 as a starting position. The rectangular columnar body can make the position of the humeral stem 21 more stable and less prone to rotation.

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

As shown in fig. 5, in the present embodiment, a second connection hole is formed on the radius bulb 32, and the radius shaft 31 includes a second connection rod inserted into the second connection hole, and the second connection rod is fitted into the second connection hole, and specifically, the second connection rod has a taper angle in the range of 5 ° 40'± 5'.

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

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

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.

For ease of description, spatially relative terms such as "over … …", "over … …", "over … …", "over", and the like may be used herein to describe the spatial relationship of one device or feature to another device or feature as shown 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 … …" may include both orientations 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. An elbow joint prosthesis, comprising:

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

a humeral prosthesis (20) comprising 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);

a radius prosthesis (30) comprising a radius stem (31) and a radius bulb (32) disposed at an end of the radius stem (31), the radius bulb (32) being rotatably disposed within the second recess (12);

an ulna prosthesis (40), wherein the ulna prosthesis (40) is detachably mounted on the lower surface of the connecting block (10);

a connection structure (50) provided between the ulnar prosthesis (40) and a lower surface of the connection block (10);

wherein the ulnar prosthesis (40) is slidably mounted on the lower surface of the connecting block (10) by the connecting structure (50).

2. The 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) 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).

3. The elbow joint prosthesis according to claim 2, wherein the connecting block (10) further comprises a limit protrusion (15) provided on a side wall of the lower protrusion (141) facing the connecting structure (50), the limit protrusion (15) being provided to protrude toward the ulnar prosthesis (40), a receiving space (16) being formed between the limit protrusion (15) and the first region (13), the ulnar prosthesis (40) comprising a platform (41), the connecting structure (50) being provided between the first region (13) and the platform (41), a part of the structure of the platform (41) being located in the receiving space (16).

4. The elbow joint prosthesis according to claim 2, characterized in that the connecting structure (50) comprises a sliding slot (51) and a sliding block (52), one of the sliding slot (51) and the sliding block (52) being arranged in the first region (13) and the other of the sliding slot (51) and the sliding block (52) being arranged on the ulnar prosthesis (40), the sliding slot (51) extending in a direction perpendicular to the direction from the first region (13) to the second region (14).

5. The elbow joint prosthesis according to claim 4, characterized in that the sliding slot (51) is provided in the first region (13), the slider (52) is provided on the upper surface of the ulnar prosthesis (40), and the width of the sliding slot (51) is gradually reduced and the width of the slider (52) is gradually reduced in a direction from the humeral prosthesis (20) to the ulnar prosthesis (40).

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

7. The elbow joint 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 backstop (5121).

8. The elbow 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 (41).

9. The elbow joint prosthesis according to claim 8, wherein a first stopper (161) and a second stopper (162) are provided at both ends of the receiving space (16), the pushing structure (60) comprises a resilient piece (61), the resilient piece (61) is folded and pressed between the first stopper (161) and the second stopper (162), and the resilient piece (61) protrudes toward the platform part (41).

10. The elbow prosthesis according to claim 3, wherein the humeral stem (21) is provided with a first baffle (211), the first baffle (211) and the humeral ball (22) are spaced apart from each other, and/or the radius stem (31) is provided with a second baffle (311), the second baffle (311) and the radius ball (32) are spaced apart from each other, and/or the ulnar prosthesis (40) further comprises an ulnar stem (42), the ulnar stem (42) is connected to the platform (41), the ulnar stem (42) is provided with a third baffle (421), the third baffle (421) and the platform (41) are spaced apart from each other, and/or the third baffle (421) and the second baffle (311) are flush with each other when the axis of the radius stem (31) and the axis of the ulnar stem (42) are parallel.