阅读说明：本技术 腕关节假体 (Wrist joint prosthesis ) 是由 王彩梅 于 2019-10-22 设计创作，主要内容包括：本发明提供了一种腕关节假体,包括：桡骨部件,具有关节面及设置在关节面上的球轴；关节衬垫,与桡骨部件活动连接,关节衬垫的底部与关节面配合,关节衬垫上设置有限位槽,限位槽包括相互连通的第一限位槽和第二限位槽,第一限位槽沿第一方向延伸,第二限位槽沿第二方向延伸；板体,连接在关节衬垫远离桡骨部件的一侧,板体上设置有连接孔；其中,球轴位于限位槽内,关节衬垫在第一限位槽和球轴的配合下能够相对于桡骨部件沿第一方向移动,关节衬垫在第二限位槽和球轴的配合下能够相对于桡骨部件沿第二方向移动。本发明的技术方案有效地解决了相关技术中的腕关节假体内部容易脱开,导致使用寿命短的问题。(The invention provides a wrist joint prosthesis comprising: a radius component having an articular surface and a ball axle disposed on the articular surface; the joint gasket is movably connected with the radius part, the bottom of the joint gasket is matched with the joint surface, the joint gasket is provided with a limiting groove, the limiting groove comprises a first limiting groove and a second limiting groove which are communicated with each other, the first limiting groove extends along a first direction, and the second limiting groove extends along a second direction; the plate body is connected to one side, away from the radius part, of the joint gasket, and a connecting hole is formed in the plate body; the ball shaft is located in the limiting groove, the joint gasket can move along a first direction relative to the radius component under the matching of the first limiting groove and the ball shaft, and the joint gasket can move along a second direction relative to the radius component under the matching of the second limiting groove and the ball shaft. The technical scheme of the invention effectively solves the problem of short service life caused by easy disengagement of the interior of the wrist joint prosthesis in the related technology.)

1. A wrist prosthesis, comprising:

a radial component (10) having an articular surface (11) and a ball axle (12) disposed on the articular surface (11);

the joint gasket (20) is movably connected with the radius component (10), the bottom of the joint gasket (20) is matched with the joint surface (11), a limiting groove is formed in the joint gasket (20), the limiting groove comprises a first limiting groove (21) and a second limiting groove (22) which are communicated with each other, the first limiting groove (21) extends along a first direction (S1), and the second limiting groove (22) extends along a second direction (S2);

the plate body (30) is connected to one side, away from the radius part (10), of the joint gasket (20), and a connecting hole is formed in the plate body (30);

wherein the ball axle (12) is located within the retaining groove, the joint spacer (20) is movable relative to the radius component (10) in the first direction (S1) in cooperation with the first retaining groove (21) and the ball axle (12), and the joint spacer (20) is movable relative to the radius component (10) in the second direction (S2) in cooperation with the second retaining groove (22) and the ball axle (12).

2. The wrist joint prosthesis according to claim 1,

the ball axle (12) comprises a ball body (121) and a shaft portion (122) arranged between the ball body (121) and the joint surface (11), the radial dimension of the shaft portion (122) being smaller than the maximum radial dimension of the ball body (121);

the first limit groove (21) comprises a first groove section (211) matched with the shaft part (122) and a second groove section (212) matched with the ball main body (121), the groove width of the first groove section (211) is smaller than that of the second groove section (212), and a notch of the first limit groove (21) is formed on the first groove section (211);

the second limit groove (22) includes a third groove section (221) engaged with the shaft portion (122) and a fourth groove section (222) engaged with the ball body (121), a groove width of the third groove section (221) is smaller than a groove width of the fourth groove section (222), and a notch of the second limit groove (22) is formed on the third groove section (221).

3. Wrist prosthesis according to claim 2, characterized in that the joint surface (11) is concave spherical, the first direction (S1) being a first arc direction in a circle with its center coinciding with the spherical center of the spherical surface in which the joint surface (11) is located, the second direction (S2) being a second arc direction in a circle with its center coinciding with the spherical center of the spherical surface in which the joint surface (11) is located.

4. The wrist joint prosthesis according to claim 2, characterized in that the ball body (121) has a top surface, which is a plane (1211).

5. The wrist joint prosthesis according to claim 1, characterized in that the plate body (30) comprises a base plate (32) and a first side plate (33) arranged outside the base plate (32), the first side plate (33) and the base plate (32) form a first obtuse included angle (a), and the connection hole comprises a first connection hole (311) arranged on the first side plate (33).

6. The wrist joint prosthesis according to claim 5, characterized in that the plate body (30) further comprises a second side plate (34) disposed inside the base plate (32), a second obtuse included angle (B) is formed between the second side plate (34) and the base plate (32), the connecting hole further comprises a second connecting hole (312) disposed on the second side plate (34), and the angle of the second obtuse included angle (B) is greater than or equal to the angle of the first obtuse included angle (A).

7. The wrist joint prosthesis according to claim 5, characterized in that the substrate (32) comprises a first porous metal layer (321), a first solid metal layer (322) and a second porous metal layer (323) arranged in sequence from top to bottom, and the pore size of the first porous metal layer (321) is smaller than that of the second porous metal layer (323).

8. The wrist joint prosthesis according to claim 7, characterized in that the plate body (30) further comprises positioning spikes (35) provided on the base plate (32), the bottom of the positioning spikes (35) passing through the first porous metal layer (321) and being connected with the first solid metal layer (322).

9. The wrist joint prosthesis according to claim 6, characterized in that the first side plate (33) and the second side plate (34) comprise a third porous metal layer (331) and a second solid metal layer (332) arranged from top to bottom.

10. The wrist joint prosthesis according to claim 6, further comprising a first locking screw (41) disposed in the first connection hole (311) and a second locking screw (42) disposed in the second connection hole (312), the joint spacer (20) being made of a polymer material.

Technical Field

The invention relates to the field of artificial prostheses, in particular to a wrist joint prosthesis.

Background

The wrist joint is composed of 4 mutually-related joints, namely a radial wrist joint, a distal radioulnar joint, a wrist middle joint and a carpometacarpal joint, is one of joints with complex functions of a human body, perfectly reflects the functions of hands and depends on orderly normal activities of the 4 joints, but the wrist joint is also a frequently-occurring part of various orthopedic diseases and traumas, such as rheumatoid arthritis, osteoarthritis, suppurative arthritis, traumatic arthritis and the like.

In the related art, the treatment means for orthopedic disorders of wrist joint is mainly wrist joint replacement (Total Wristarthreshold TWA), which is to replace the affected radial wrist and the middle wrist joint part with artificial joint prosthesis, relieve pain of the patient by replacing the affected joint and partially restore the function of the hand of the patient. However, due to the complexity and specificity of the anatomy and function of the wrist joint, the problems of prosthesis life and fixation have not been well solved.

Disclosure of Invention

The invention aims to provide a wrist joint prosthesis, which aims to solve the problem that the inside of the wrist joint prosthesis in the prior art is easy to disengage, so that the service life is short.

In order to achieve the above object, the present invention provides a wrist joint prosthesis comprising: a radius component having an articular surface and a ball axle disposed on the articular surface; the joint gasket is movably connected with the radius part, the bottom of the joint gasket is matched with the joint surface, the joint gasket is provided with a limiting groove, the limiting groove comprises a first limiting groove and a second limiting groove which are communicated with each other, the first limiting groove extends along a first direction, and the second limiting groove extends along a second direction; the plate body is connected to one side, away from the radius part, of the joint gasket, and a connecting hole is formed in the plate body; the ball shaft is located in the limiting groove, the joint gasket can move along a first direction relative to the radius component under the matching of the first limiting groove and the ball shaft, and the joint gasket can move along a second direction relative to the radius component under the matching of the second limiting groove and the ball shaft.

Further, the ball axle includes a ball body and an axle portion disposed between the ball body and the articular surface, the axle portion having a radial dimension less than a maximum radial dimension of the ball body; the first limiting groove comprises a first groove section matched with the shaft part and a second groove section matched with the ball main body, the groove width of the first groove section is smaller than that of the second groove section, and a notch of the first limiting groove is formed in the first groove section; the second spacing groove includes with axial region complex third groove segment and with ball main part complex fourth groove segment, the groove width of third groove segment is less than the groove width of fourth groove segment, the notch of second spacing groove forms on the third groove segment. The ball shaft is divided into a ball body and a shaft part arranged at the bottom of the ball body, the ball body is spherical, and the diameter of the shaft part is smaller than the maximum diameter of the ball body. The groove width of the first groove section is smaller than that of the second groove section, the ball main body of the ball shaft can be arranged in the second groove section, and the shaft part can be arranged in the first groove section; similarly, the matching of the third groove section and the fourth groove section with the ball shaft is similar to the matching of the first groove section and the ball shaft of the first groove section. The mutual cooperation of first groove section, second groove section, third groove section and fourth groove section can make the ball axle move in four groove sections.

Furthermore, the joint surface is a concave spherical surface, the first direction is a first arc direction, the center of a circle where the first arc direction is located coincides with the center of a sphere where the joint surface is located, the second direction is a second arc direction, and the center of a circle where the second arc direction is located coincides with the center of a sphere where the joint surface is located. The joint surface is contacted with the bottom surface of the joint gasket, the joint surface is in a concave spherical surface shape, and the bottom surface of the gasket is in a convex spherical surface shape.

Further, the ball body has a top surface that is planar. The top surface is set to be a plane and can be matched with the inner top surface of the limiting groove, so that the rotation angle of the ball shaft can be further limited.

Further, the plate body comprises a substrate and a first side plate arranged on the outer side of the substrate, a first obtuse included angle is formed between the first side plate and the substrate, and the connecting hole comprises a first connecting hole arranged on the first side plate. The first side plate can be in contact with the pisiform bone, the triquetrum bone and the hamate bone on the side far away from the thumb. The first connecting hole penetrates through the first side plate.

Further, the plate body further comprises a second side plate arranged on the inner side of the base plate, a second obtuse included angle is formed between the second side plate and the base plate, the connecting hole comprises a second connecting hole arranged on the second side plate, and the angle of the second obtuse included angle is larger than or equal to that of the first obtuse included angle. The second side plate may be in contact with a trapezium bone on a side close to the thumb. The second connecting hole penetrates through the second side plate.

Further, the substrate comprises a first porous metal layer, a first solid metal layer and a second porous metal layer which are sequentially arranged from top to bottom, and the aperture of the first porous metal layer is smaller than that of the second porous metal layer. The substrate comprises a three-layer structure, wherein the first solid metal layer is arranged between the first porous metal layer and the second porous metal layer.

Furthermore, the plate body also comprises a positioning spike arranged on the substrate, and the bottom of the positioning spike penetrates through the first porous metal layer and is connected with the first solid metal layer. The positioning spikes and the first solid metal layer are of an integral structure, namely the positioning spikes are also of solid metal.

Further, the first side plate and the second side plate comprise a third porous metal layer and a second solid metal layer which are arranged from top to bottom. The first side plate and the second side plate are of a two-layer structure, the third porous metal layer of the first side plate can be in contact with the pisiform bone, the triquetrum bone and the hamate bone, the third porous metal layer of the second side plate can be in contact with the trapezium bone, and the second solid metal layer is arranged on the inner side of the third porous metal layer.

Further, the wrist joint prosthesis further comprises a first locking screw disposed in the first coupling hole and a second locking screw disposed in the second coupling hole, and the joint spacer is made of a polymer material. Extension lines of the first locking screw and the second locking screw are arranged in a crossed mode.

By applying the technical scheme of the invention, the wrist joint prosthesis comprises a radius component, a joint gasket and a plate body. The radius component is connected to the radius of the patient and the plate is connected to the bone of the patient remaining after the osteotomy. The radius part is provided with a joint surface and a ball shaft arranged on the joint surface, the ball shaft is matched with a limiting groove in the joint gasket, and the joint surface is contacted with the bottom surface of the joint gasket. The limiting groove comprises a first limiting groove extending along the first direction and a second limiting groove extending along the second direction, and the first limiting groove is communicated with the second limiting groove. Through the cooperation of ball axle and first spacing groove and second spacing groove, the joint pad can slide for the articular surface, can slide along first direction and slide along the second direction. Due to the limiting effect between the first limiting groove and the spherical shaft and between the second limiting groove and the spherical shaft, the motion track of the joint gasket relative to the joint surface is limited, and further effective limitation on the joint gasket can be realized, so that the radius part is not easy to separate from the joint gasket, and the structure of the wrist joint prosthesis is more stable.

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 cross-sectional schematic view of an embodiment of a wrist joint prosthesis according to the invention;

FIG. 2 shows a cross-sectional schematic view of the radial assembly of the wrist prosthesis of FIG. 1;

figure 3 shows a cross-sectional view of the joint spacer and plate body of the wrist prosthesis of figure 1;

FIG. 4 illustrates a perspective view of a partial structure of the radius assembly of FIG. 2;

FIG. 5 is a perspective view of a portion of the radial assembly of FIG. 4 in a configuration for mating with a joint spacer;

FIG. 6 illustrates a side view of a portion of the radial assembly of FIG. 5 with a joint spacer;

FIG. 7 is a schematic cross-sectional view taken along line A-A of the radial assembly of FIG. 6 and a joint spacer;

FIG. 8 illustrates a top view of a portion of the radial assembly of FIG. 5 with a joint spacer;

FIG. 9 is a schematic cross-sectional view taken along line B-B of the radial assembly of FIG. 8 and a joint spacer;

FIG. 10 is a perspective view of a partial structure of the radius assembly of FIG. 5 with a joint spacer;

figure 11 shows a perspective view of a joint spacer of the wrist prosthesis of figure 5;

FIG. 12 shows a side schematic view of the joint spacer of FIG. 11;

FIG. 13 shows a schematic cross-sectional view of the joint spacer of FIG. 12 in the direction C-C;

FIG. 14 shows a top schematic view of the joint spacer of FIG. 11;

FIG. 15 shows a schematic cross-sectional view of the joint spacer of FIG. 14 taken along line D-D;

FIG. 16 shows a schematic side view of a partial structure of the radial component of the wrist prosthesis of FIG. 4;

FIG. 17 is a schematic cross-sectional view taken along line E-E of the radial assembly of FIG. 16;

FIG. 18 illustrates a schematic top view of a portion of the radial assembly of FIG. 16; and

fig. 19 shows a schematic sectional view of a portion of the radial assembly of fig. 18 in the direction F-F.

Wherein the figures include the following reference numerals:

10. a radial component; 11. a joint surface; 12. a ball shaft; 121. a ball body; 1211. a plane; 122. a shaft portion; 20. a joint spacer; 21. a first limit groove; 211. a first groove section; 212. a second groove section; 22. a second limit groove; 221. a third groove section; 222. a fourth groove section; 30. a plate body; 311. a first connection hole; 312. a second connection hole; 32. a substrate; 321. a first porous metal layer; 322. a first solid metal layer; 323. a second porous metal layer; 33. a first side plate; 331. a third porous metal layer; 332. a second solid metal layer; 34. a second side plate; 35. positioning the spine; 41. a first locking screw; 42. a second locking screw.

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.

As shown in fig. 1, 2, 4, 13 and 15, in the present embodiment, the wrist joint prosthesis includes: a radius component 10, a joint spacer 20, and a plate body 30. The radial component 10 has an articular surface 11 and a ball axle 12 disposed on the articular surface 11. The joint gasket 20 is movably connected with the radius part 10, the bottom of the joint gasket 20 is matched with the joint surface 11, a limiting groove is formed in the joint gasket 20 and comprises a first limiting groove 21 and a second limiting groove 22 which are communicated with each other, the first limiting groove 21 extends along a first direction S1, and the second limiting groove 22 extends along a second direction S2. The plate body 30 is attached to the side of the joint spacer 20 away from the radius component 10, and the plate body 30 is provided with an attachment hole. Wherein, the ball axle 12 is located in the limiting groove, the joint gasket 20 can move along a first direction relative to the radius part 10 under the matching of the first limiting groove 21 and the ball axle 12, and the joint gasket 20 can move along a second direction relative to the radius part 10 under the matching of the second limiting groove 22 and the ball axle 12.

With the technical solution of the present embodiment, the wrist joint prosthesis includes a radius part 10, a joint spacer 20, and a plate body 30. The radius part 10 is coupled to the radius of the patient, and the plate body 30 is coupled to the cut bone between the metacarpal bone and the radius of the patient. The radial component 10 has an articular surface 11 and a ball 12 disposed on the articular surface 11, the ball 12 engaging a limiting groove in the joint spacer 20, the articular surface 11 contacting the bottom surface of the joint spacer 20. The limiting groove comprises a first limiting groove 21 extending along the first direction and a second limiting groove 22 extending along the second direction, and the first limiting groove 21 and the second limiting groove 22 are communicated with each other. By the cooperation of the ball axle 12 and the first and second limiting grooves 21 and 22, the joint spacer 20 can slide relative to the joint surface 11, i.e., can slide in the first direction and in the second direction. Due to the limiting effect between the first limiting groove 21 and the second limiting groove 22 and the ball shaft 12, the motion track of the joint gasket 20 relative to the joint surface is limited, and further the effective limiting of the joint gasket 20 can be realized, so that the radius part 10 is not easy to separate from the joint gasket 20, and the structure of the wrist joint prosthesis is more stable. In the case of replacement of the wrist joint prosthesis, the bone between the metacarpal bone and the radius bone is cut according to the thickness of the joint spacer 20, so that the joint spacer 20 can be butted against the cut bone. Generally, before the hand bones are coupled to the plate body 30, scaphoid bones and lunate bones may be osteotomized.

As shown in fig. 5 to 15, in the present embodiment, the ball axle 12 includes a ball body 121 and a shaft portion 122 disposed between the ball body 121 and the joint surface 11, and a radial dimension of the shaft portion 122 is smaller than a maximum radial dimension of the ball body 121; the first stopper groove 21 includes a first groove section 211 engaged with the shaft portion 122 and a second groove section 212 engaged with the ball body 121, the groove width of the first groove section 211 is smaller than that of the second groove section 212, and a notch of the first stopper groove 21 is formed on the first groove section 211; the second stopper groove 22 includes a third groove section 221 engaged with the shaft portion 122 and a fourth groove section 222 engaged with the ball body 121, the groove width of the third groove section 221 is smaller than that of the fourth groove section 222, and a notch of the second stopper groove 22 is formed on the third groove section 221. The ball shaft 12 is divided into a ball body 121 and a shaft portion 122 provided at the bottom of the ball body 121, the ball body 121 is spherical, and the diameter of the shaft portion 122 is smaller than the maximum diameter of the ball body 121. The first groove section 211 has a smaller groove width than the second groove section 212, the ball body 121 of the ball axle 12 may be located in the second groove section 212, and the shaft portion 122 may be located in the first groove section 211; similarly, the third groove section 221 and the fourth groove section 222 are matched with the ball axle 12 similarly to the first groove section 211 and the second groove section 212 are matched with the ball axle 12. The cooperation of the first slot segment 211, the second slot segment 212, the third slot segment 221 and the fourth slot segment 222 can enable the ball axle 12 to move in the four slot segments. The arrangement of the first groove section 211 and the third groove section 221 can effectively prevent the ball axle 12 from being separated from the joint spacer 20.

As shown in fig. 3, 4, 16 to 19, in the present embodiment, the joint surface 11 is a concave spherical surface, the first direction is a first arc direction, a center of a circle of the first arc direction coincides with a center of a sphere of the spherical surface where the joint surface 11 is located, and a center of a circle of the second arc direction coincides with a center of a sphere of the spherical surface where the joint surface 11 is located. The structure can ensure that the ball shaft 12 can stably move in the limit groove.

As shown in fig. 2 and 4, in the present embodiment, the ball body 121 has a top surface, which is a plane 1211. The top surface is a plane 1211, which can cooperate with the inner top surface of the limiting groove to further limit the rotation angle of the ball axle 12, thereby achieving the dual limiting function. Meanwhile, the plane 1211 formed on the top surface of the ball body 121 may reduce the height of the entire wrist prosthesis while considering the structural strength.

As shown in fig. 3, the plate body 30 includes a base plate 32 and a first side plate 33 disposed outside the base plate 32, a first obtuse included angle a is formed between the first side plate 33 and the base plate 32, and the connecting holes include a first connecting hole 311 disposed on the first side plate 33. The base plate 32 and the first side plate 33 are in contact with bones remaining after osteotomy, the first side plate 33 is in contact with the pisiform, the triquetrum and the hamate side wall, the first side plate 33 is in contact with the pisiform, the triquetrum and the hamate on the side far away from the thumb, and the first side plate 33 is longer than the second side plate 34 by a first obtuse included angle A so that the contact area of the first side plate 33 with the pisiform, the triquetrum and the hamate is larger. The base plate 32 and the first side plate 33 cooperate with each other to stabilize the fixation of the wrist prosthesis. Meanwhile, the first side plate 33 is disposed obliquely with respect to the base plate 32 such that the first locking screw 41 disposed in the first coupling hole 311 is disposed obliquely. Thus, the first locking screw 41 is not easily driven into the metacarpal bone, and is only connected to a bone between the metacarpal bone and the radius bone, such as the trapezium bone.

As shown in fig. 1 and fig. 3, in the present embodiment, the plate body 30 further includes a second side plate 34 disposed on the inner side of the base plate 32, a second obtuse included angle B is formed between the second side plate 34 and the base plate 32, the connecting hole includes a second connecting hole 312 disposed on the second side plate 34, and an angle of the second obtuse included angle B is greater than an angle of the first obtuse included angle a. Meanwhile, the second side plate 34 is disposed to be inclined with respect to the base plate 32 such that the second locking screw 42 disposed in the second coupling hole 312 is disposed to be inclined. Thus, the second locking screw 42 is not easily driven into the metacarpal bone and only engages the bone between the metacarpal bone and the radius, such as the pisiform bone, the triquetrum bone, or the hamate bone.

The second obtuse included angle B is provided to provide a greater contact area of the second side panel 34 with the pisiform, triquetrum, and hamate bones. The base plate 32 and the second side plate 34 cooperate to provide more stable fixation of the wrist prosthesis.

In embodiments not shown, the second obtuse included angle is equal to the first obtuse included angle, as long as the contact area between the first side plate and the trapezium, and between the second side plate and the pisiform, triquetrum and hamate is maximized. The connection of the wrist joint prosthesis between the metacarpal bone and the radius bone can be more stable.

The first obtuse included angle A is between 100 and 130 degrees, and the second obtuse included angle B is between 125 and 155 degrees. Preferably, the first obtuse included angle a is 115 ° and the second obtuse included angle B is 145 °.

As shown in fig. 3, in the present embodiment, the substrate 32 includes a first porous metal layer 321, a first solid metal layer 322, and a second porous metal layer 323 sequentially disposed from top to bottom, and the pore diameter of the first porous metal layer 321 is smaller than that of the second porous metal layer 323. The first porous metal layer 321 directly contacts with the bone remained after the osteotomy, and the first porous metal layer 321 is of a porous metal structure, so that the effect is better. The first solid metal layer 322 can increase the overall structural strength and stabilize the structure of the wrist prosthesis. The second porous metal layer 323 is a porous metal structure with a larger aperture, and can be fixed more stably with the joint spacer 20, and is not easy to fall off.

As shown in fig. 3, in the present embodiment, the plate body 30 further includes a positioning spike 35 disposed on the substrate 32, and a bottom portion of the positioning spike 35 penetrates through the first porous metal layer 321 and is connected to the first solid metal layer 322. The location spine 35 can provide the effect of location when the wrist joint prosthesis is installed to motion between the metacarpal joint when can preventing to drill causes the unstability, can alleviate the positioning action of curb plate simultaneously, makes the curb plate play more fixed action, and the location spine 35 conveniently implants, fixes a position, and motion between the metacarpal joint when preventing to drill causes the unstability. The positioning spike 35 is integrated with the first solid metal layer 322, i.e. the structural strength of the positioning spike 35 is better.

As shown in fig. 3, in the present embodiment, the first side plate 33 and the second side plate 34 include a third porous metal layer 331 and a second solid metal layer 332 arranged from top to bottom. The third porous metal layer 331 is in contact with the bone remaining after the osteotomy. The second solid metal layer 332 can improve the structural strength of the first side plate 33 and the second side plate 34, so that the first side plate 33 and the second side plate 34 can play a certain supporting role in the wrist joint prosthesis.

As shown in fig. 1 and 3, in the present embodiment, the wrist joint prosthesis further includes a first locking screw 41 disposed in the first coupling hole 311 and a second locking screw 42 disposed in the second coupling hole 312, and the joint spacer 20 is made of a polymer material. The first locking screw 41 and the second locking screw 42 play a role in fixing the wrist joint prosthesis, the first locking screw 41 and the second locking screw 42 are of a non-parallel structure, namely extension lines where the first locking screw 41 and the second locking screw 42 are located are intersected, so that the connection between the upper part (the joint gasket 20 and the plate body 30) of the wrist joint prosthesis and a bone reserved after osteotomy is stable, the wrist joint prosthesis is not easy to fall off, and the first locking screw 41 and the second locking screw 42 can be prevented from being driven into a metacarpal bone. The polymer selected for the joint spacer 20 is a material having hardness and elasticity similar to those of natural human cartilage, preferably polyurethane TPU material, polyvinyl alcohol gel, polylactic acid, etc. The polymer has good ductility, breaking strength, wear resistance and biocompatibility, so that the polymer can be well combined with the porous trabecular metal layer to ensure the overall performance of the long-term implantation of the prosthesis.

As shown in fig. 1, in the present embodiment, the primary connection between the base plate and the patient's hand bone is the first locking screw 41 and the second locking screw 42, and the positioning spike 35 primarily serves as the positioning. The positioning spikes 35 can therefore be provided relatively short, as far as possible without striking the metacarpal bone. Since the first locking screw 41 and the second locking screw 42 are both obliquely arranged, they are not driven into the metacarpal bone. Compared with the wrist joint prosthesis driven into the metacarpal bone in the prior art, the scheme of the embodiment is safe for patients and has less harm.

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.