Wrist joint prosthesis

Abstract

The present invention provides a wrist joint prosthesis, comprising: a radius component having an articular surface and a ball shaft provided on the articular surface; an articular liner movably connected to the radius component, the bottom of the articular liner being adapted to the articular surface, and a limiting groove being provided on the articular liner, the limiting groove including a first limiting groove and a second limiting groove communicating with each other, the first limiting groove extending along a first direction and the second limiting groove extending along a second direction; a plate body connected to the side of the articular liner away from the radius component, and a connecting hole being provided on the plate body; wherein, the ball shaft is located in the limiting groove, and the articular liner can move relative to the radius component along the first direction under the cooperation of the first limiting groove and the ball shaft, and the articular liner can move relative to the radius component along the second direction under the cooperation of the second limiting groove and the ball shaft. The technical solution of the present invention effectively solves the problem that the internal parts of the wrist joint prosthesis in the related art are prone to come apart, resulting in a short service life.

Description

Technical Field

[0001] The present invention relates to the field of artificial prostheses, and more particularly to a wrist joint prosthesis. Background Art

[0002] The wrist joint is composed of four interrelated joints: the radiocarpal joint, the distal radioulnar joint, the midcarpal joint, and the carpometacarpal joint. It is one of the joints with relatively complex functions in the human body. The perfect manifestation of the hand's function also depends on the orderly and normal activities of these four joints. However, the wrist joint is also a frequent site for many orthopedic diseases and traumas, such as rheumatoid arthritis, osteoarthritis, septic arthritis, traumatic arthritis, etc.

[0003] In the related art, the main treatment method for wrist joint orthopedic diseases is total wrist arthroplasty (TWA). Wrist joint replacement uses an artificial joint prosthesis to replace the radiocarpal and midcarpal joint parts on the affected side, and by replacing the diseased joint, it can relieve the patient's pain and partially restore the function of the patient's hand. However, due to the complexity and particularity of the wrist joint's anatomy and function, the service life and fixation problems of the prosthesis have not been well solved. Summary of the Invention

[0004] The present invention aims to provide a wrist joint prosthesis to solve the problem in the prior art that the interior of the wrist joint prosthesis is prone to come apart, resulting in a short service life.

[0005] To achieve the above object, the present invention provides a wrist joint prosthesis, comprising: a radius component having an articular surface and a ball shaft provided on the articular surface; an articular liner movably connected to the radius component, the bottom of the articular liner being adapted to the articular surface, and a limiting groove being provided on the articular liner, the limiting groove including a first limiting groove and a second limiting groove that communicate with each other, the first limiting groove extending along a first direction, and the second limiting groove extending along a second direction; a plate body connected to the side of the articular liner away from the radius component, and a connection hole being provided on the plate body; wherein, the ball shaft is located in the limiting groove, and the articular liner can move relative to the radius component along the first direction under the cooperation of the first limiting groove and the ball shaft, and the articular liner can move relative to the radius component along the second direction under the cooperation of the second limiting groove and the ball shaft.

[0006] Further, the ball shaft includes a ball body and a shaft portion disposed between the ball body and the joint surface. The radial dimension of the shaft portion is smaller than the maximum radial dimension of the ball body. The first limiting groove includes a first groove section that mates with the shaft portion and a second groove section that mates with the ball body. The groove width of the first groove section is smaller than that of the second groove section, and the notch of the first limiting groove is formed on the first groove section. The second limiting groove includes a third groove section that mates with the shaft portion and a fourth groove section that mates with the ball body. The groove width of the third groove section is smaller than that of the fourth groove section, and the notch of the second limiting groove is formed on the third groove section. The above-mentioned ball shaft is divided into a ball body and a shaft portion disposed at the bottom of the ball body. The ball body is spherical, and the diameter of the shaft portion 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 body of the ball shaft can be inserted into the second groove section, and the shaft portion can be inserted into the first groove section. Similarly, the cooperation between the third groove section and the fourth groove section and the ball shaft is similar to the cooperation between the first groove section, the second groove section and the ball shaft. The mutual cooperation of the first groove section, the second groove section, the third groove section and the fourth groove section enables the ball shaft to move within the four groove sections.

[0007] Further, the joint surface is in the shape of a concave spherical surface. The first direction is the first arc direction, and the center of the circle where the first arc direction is located coincides with the center of the spherical surface where the joint surface is located. The second direction is the second arc direction, and the center of the circle where the second arc direction is located coincides with the center of the spherical surface where the joint surface is located. The above-mentioned joint surface contacts the bottom surface of the joint pad. The joint surface is in the shape of a concave spherical surface, and the bottom surface of the pad is in the shape of a convex spherical surface.

[0008] Further, the ball body has a top surface, and the top surface is a plane. By setting the top surface as a plane, it can cooperate with the inner top surface of the limiting groove, and can further limit the rotation angle of the ball shaft.

[0009] Further, the plate body includes a base plate and a first side plate disposed on the outer side of the base plate. A first obtuse angle is formed between the first side plate and the base plate. The connecting hole includes a first connecting hole disposed on the first side plate. The above-mentioned first side plate can contact the pisiform bone, the triquetral bone and the hamate bone on the side away from the thumb. The first connecting hole penetrates the first side plate.

[0010] Further, the plate body further includes a second side plate disposed on the inner side of the base plate. A second obtuse angle is formed between the second side plate and the base plate. The connecting hole includes a second connecting hole disposed on the second side plate, and the angle of the second obtuse angle is greater than or equal to the angle of the first obtuse angle. The above-mentioned second side plate can contact the trapezium bone on the side close to the thumb. The second connecting hole penetrates the second side plate.

[0011] Further, the substrate includes a first porous metal layer, a first solid metal layer, and a second porous metal layer arranged in sequence from top to bottom, and the pore diameter of the first porous metal layer is smaller than that of the second porous metal layer. The above-mentioned substrate includes a three-layer structure, and the first solid metal layer is between the first porous metal layer and the second porous metal layer.

[0012] Further, the plate body further includes positioning spikes arranged on the substrate, and the bottom of the positioning spikes passes through the first porous metal layer and is connected to the first solid metal layer. The above-mentioned positioning spikes and the first solid metal layer are of an integral structure, that is, the positioning spikes are also solid metals.

[0013] Further, the first side plate and the second side plate include a third porous metal layer and a second solid metal layer arranged from top to bottom. The above-mentioned first side plate and second side plate are of a two-layer structure. The third porous metal layer of the first side plate can contact the pisiform bone, the triquetral bone, and the hamate bone, and the third porous metal layer of the second side plate can contact the trapezium bone. The second solid metal layer is inside the third porous metal layer.

[0014] Further, the wrist joint prosthesis further includes a first locking screw arranged in the first connection hole and a second locking screw arranged in the second connection hole, and the articular liner is made of a polymer material. The extension lines of the above-mentioned first locking screw and second locking screw are arranged crosswise.

[0015] Applying the technical solution of the present invention, the wrist joint prosthesis includes a radial component, an articular liner, and a plate body. The radial component is connected to the radius bone of the patient, and the plate body is connected to the bone retained after osteotomy of the patient. The radial component has an articular surface and a ball shaft arranged on the articular surface. The ball shaft cooperates with the limiting groove in the articular liner, and the articular surface contacts the bottom surface of the articular liner. The limiting groove includes a first limiting groove extending in a first direction and a second limiting groove extending in a second direction, and the first limiting groove communicates with the second limiting groove. Through the cooperation of the ball shaft with the first limiting groove and the second limiting groove, the articular liner can slide relative to the articular surface, that is, it can slide in the first direction and slide in the second direction. Due to the limiting effect between the first limiting groove and the second limiting groove and the ball shaft, the movement track of the articular liner relative to the articular surface is limited, and thus the effective limitation of the articular liner can be achieved. In this way, the radial component is not easily separated from the articular liner, making the structure of the wrist joint prosthesis more stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0017] Figure 1 A cross-sectional schematic view showing an embodiment of a wrist joint prosthesis according to the present invention is shown;

[0018] Figure 2 shows Figure 1 a cross-sectional schematic view of the radial component of the wrist joint prosthesis of

[0019] Figure 3 shows Figure 1 a cross-sectional schematic view of the articular liner and the plate body of the wrist joint prosthesis of

[0020] Figure 4 shows Figure 2 a three-dimensional schematic view of a partial structure of the radial component of

[0021] Figure 5 shows Figure 4 a three-dimensional schematic view of the mating structure of a partial structure of the radial component and the articular liner of

[0022] Figure 6 shows Figure 5 a side view schematic of a partial structure of the radial component and the articular liner of

[0023] Figure 7 shows Figure 6 a sectional view along line A-A of a partial structure of the radial component and the articular liner of

[0024] Figure 8 shows Figure 5 a top view schematic of a partial structure of the radial component and the articular liner of

[0025] Figure 9 shows Figure 8 a sectional view along line B-B of a partial structure of the radial component and the articular liner of

[0026] Figure 10 shows Figure 5 a three-dimensional perspective schematic of a partial structure of the radial component and the articular liner of

[0027] Figure 11 shows Figure 5 a three-dimensional schematic view of the articular liner of the wrist joint prosthesis of

[0028] Figure 12 shows Figure 11 a side view schematic of the articular liner of

[0029] Figure 13 shows Figure 12 a sectional view along line C-C of the articular liner of

[0030] Figure 14 shows Figure 11 a top view schematic of the articular liner of

[0031] Figure 15Shows Figure 14 A schematic D-D sectional view of the joint pad;

[0032] Figure 16 Shows Figure 4 A schematic side view of a partial structure of the radial component of the wrist joint prosthesis;

[0033] Figure 17 Shows Figure 16 A schematic E-E sectional view of a partial structure of the radial component;

[0034] Figure 18 Shows Figure 16 A schematic top view of a partial structure of the radial component; and

[0035] Figure 19 Shows Figure 18 A schematic F-F sectional view of a partial structure of the radial component.

[0036] Among them, the above-mentioned drawings include the following reference numerals:

[0037] 10. Radial component; 11. Articular surface; 12. Ball shaft; 121. Ball body; 1211. Plane; 122. Shaft portion; 20. Joint pad; 21. First limiting groove; 211. First groove section; 212. Second groove section; 22. Second limiting groove; 221. Third groove section; 222. Fourth groove section; 30. Plate body; 311. First connection hole; 312. Second connection hole; 32. Substrate; 321. First porous metal layer; 322. First solid metal layer; 323. Second porous metal layer; 33. First side plate; 331. Third porous metal layer; 332. Second solid metal layer; 34. Second side plate; 35. Positioning spike; 41. First locking screw; 42. Second locking screw. Detailed implementation manners

[0038] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way limits the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0039] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they specify the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0040] Unless otherwise specifically stated, the relative arrangements of the components and steps set forth in these embodiments, numerical expressions, and numerical values do not limit the scope of the present invention. At the same time, it should be understood that for the convenience of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the said technologies, methods, and devices should be regarded as part of the authorized specification. In all the examples shown and discussed here, any specific value should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0041] As Figure 1 、 Figure 2 、 Figure 4 、 Figure 13 and Figure 15 shown, in this embodiment, the wrist joint prosthesis includes: a radial component 10, an articular liner 20, and a plate body 30. The radial component 10 has an articular surface 11 and a ball shaft 12 provided on the articular surface 11. The articular liner 20 is movably connected to the radial component 10. The bottom of the articular liner 20 cooperates with the articular surface 11. The articular liner 20 is provided with a limiting groove, and the limiting groove includes a first limiting groove 21 and a second limiting groove 22 that communicate 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 the side of the articular liner 20 away from the radial component 10, and the plate body 30 is provided with a connection hole. Among them, the ball shaft 12 is located in the limiting groove. The articular liner 20 can move relative to the radial component 10 along the first direction under the cooperation of the first limiting groove 21 and the ball shaft 12, and the articular liner 20 can move relative to the radial component 10 along the second direction under the cooperation of the second limiting groove 22 and the ball shaft 12.

[0042] Applying the technical solution of this embodiment, the wrist joint prosthesis includes a radius component 10, an articular liner 20, and a plate body 30. The radius component 10 is connected to the radius bone of the patient, and the plate body 30 is connected to the bone intercepted between the metacarpal bone and the radius bone of the patient. The radius component 10 has an articular surface 11 and a ball shaft 12 provided on the articular surface 11. The ball shaft 12 cooperates with the limit groove in the articular liner 20, and the articular surface 11 contacts the bottom surface of the articular liner 20. The limit groove includes a first limit groove 21 extending in a first direction and a second limit groove 22 extending in a second direction, and the first limit groove 21 communicates with the second limit groove 22. Through the cooperation of the ball shaft 12 with the first limit groove 21 and the second limit groove 22, the articular liner 20 can slide relative to the articular surface 11, that is, it can slide along the first direction and slide along the second direction. Due to the limiting effect between the first limit groove 21 and the second limit groove 22 and the ball shaft 12, the movement trajectory of the articular liner 20 relative to the articular surface is limited, and thus the effective limitation of the articular liner 20 can be achieved. In this way, the radius component 10 is not easily separated from the articular liner 20, making the structure of the wrist joint prosthesis more stable. It should be noted that when replacing the wrist joint prosthesis, the bone between the metacarpal bone and the radius bone is osteotomized according to the thickness of the articular liner 20 so that the articular liner 20 can be docked with the osteotomized bone. Generally, before the hand bone is connected to the plate body 30, osteotomy can be performed on the scaphoid bone and the lunate bone.

[0043] Such as Figures 5 to 15As shown, in this embodiment, the ball shaft 12 includes a ball body 121 and a shaft portion 122 disposed between the ball body 121 and the joint surface 11. The radial dimension of the shaft portion 122 is smaller than the maximum radial dimension of the ball body 121. The first limiting groove 21 includes a first groove segment 211 that cooperates with the shaft portion 122 and a second groove segment 212 that cooperates with the ball body 121. The groove width of the first groove segment 211 is smaller than the groove width of the second groove segment 212. The notch of the first limiting groove 21 is formed on the first groove segment 211. The second limiting groove 22 includes a third groove segment 221 that cooperates with the shaft portion 122 and a fourth groove segment 222 that cooperates with the ball body 121. The groove width of the third groove segment 221 is smaller than the groove width of the fourth groove segment 222. The notch of the second limiting groove 22 is formed on the third groove segment 221. The ball shaft 12 is divided into a ball body 121 and a shaft portion 122 disposed 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 groove width of the first groove segment 211 is smaller than that of the second groove segment 212. The ball body 121 of the ball shaft 12 can be located in the second groove segment 212, and the shaft portion 122 can be located in the first groove segment 211. Similarly, the cooperation between the third groove segment 221 and the fourth groove segment 222 and the ball shaft 12 is similar to the cooperation between the first groove segment 211, the second groove segment 212 and the ball shaft 12. The mutual cooperation of the first groove segment 211, the second groove segment 212, the third groove segment 221 and the fourth groove segment 222 enables the ball shaft 12 to move within the four groove segments. The arrangement of the first groove segment 211 and the third groove segment 221 can effectively prevent the ball shaft 12 from detaching from the joint gasket 20.

[0044] As Figure 3 , Figure 4 , Figures 16 to 19 shown, in this embodiment, the joint surface 11 is in the shape of a concave spherical surface. The first direction is the first arc direction. The center of the circle where the first arc direction is located coincides with the center of the spherical surface where the joint surface 11 is located. The center of the circle where the second arc direction is located coincides with the center of the spherical surface where the joint surface 11 is located. The above structure enables the ball shaft 12 to move smoothly within the limiting groove.

[0045] As Figure 2 and Figure 4 shown, in this embodiment, the ball body 121 has a top surface, and this top surface is a flat surface 1211. Setting the top surface as the flat surface 1211 can cooperate with the inner top surface of the limiting groove, can further limit the rotation angle of the ball shaft 12, and play a dual limiting role. At the same time, setting the top surface of the ball body 121 as the flat surface 1211 can reduce the height of the entire wrist joint prosthesis while taking into account the structural strength.

[0046] As Figure 3As shown, the plate body 30 includes a base plate 32 and a first side plate 33 disposed outside the base plate 32. A first obtuse angle A is formed between the first side plate 33 and the base plate 32. The connecting hole includes 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 the bone retained after osteotomy. The first side plate 33 is in contact with the pisiform bone, the triquetral bone, and the lateral wall of the hamate bone. The first side plate 33 is in contact with the pisiform bone, the triquetral bone, and the hamate bone on the side away from the thumb. The first side plate 33 is longer than the second side plate 34. The first obtuse angle A can make the contact area between the first side plate 33 and the pisiform bone, the triquetral bone, and the hamate bone larger. The cooperation between the base plate 32 and the first side plate 33 can make the fixation of the wrist joint prosthesis more stable. At the same time, the above-mentioned first side plate 33 is inclined relative to the base plate 32, which can make the first locking screw 41 disposed in the first connecting hole 311 inclined. In this way, the first locking screw 41 is not easily driven into the metacarpal bone and will only be connected to the bone between the metacarpal bone and the radius, such as the trapezium bone.

[0047] As Figure 1 and Figure 3 shown, in this 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 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. The angle of the second obtuse angle B is greater than the angle of the first obtuse angle A. At the same time, the above-mentioned second side plate 34 is inclined relative to the base plate 32, which can make the second locking screw 42 disposed in the second connecting hole 312 inclined. In this way, the second locking screw 42 is not easily driven into the metacarpal bone and will only be connected to the bone between the metacarpal bone and the radius, such as the pisiform bone, the triquetral bone, or the hamate bone.

[0048] The setting of the second obtuse angle B can make the contact area between the second side plate 34 and the pisiform bone, the triquetral bone, and the hamate bone larger. The cooperation between the base plate 32 and the second side plate 34 can make the fixation of the wrist joint prosthesis more stable.

[0049] In the embodiment not shown in the figure, the second obtuse angle is equal to the first obtuse angle, as long as the contact area between the first side plate and the trapezium bone, and the second side plate and the pisiform bone, the triquetral bone, and the hamate bone reaches the maximum. At this time, the connection between the wrist joint prosthesis between the metacarpal bone and the radius can be made more stable.

[0050] The first obtuse angle A is between 100° and 130°, and the second obtuse angle B is between 125° and 155°. Preferably, the first obtuse angle A is 115°, and the second obtuse angle B is 145°.

[0051] As Figure 3As shown, in this embodiment, the substrate 32 includes a first porous metal layer 321, a first solid metal layer 322, and a second porous metal layer 323 that are sequentially arranged from top to bottom. The pore size of the first porous metal layer 321 is smaller than that of the second porous metal layer 323. The first porous metal layer 321 is in direct contact with the bone retained after osteotomy. The first porous metal layer 321 is a porous metal structure, which makes the effect better. The first solid metal layer 322 can increase the overall structural strength and make the structure of the wrist joint prosthesis stable. The second porous metal layer 323 is a porous metal structure with a larger pore size, which can be more firmly fixed to the joint liner 20 and is not easily detached.

[0052] As Figure 3 shown, in this embodiment, the plate body 30 further includes positioning spikes 35 arranged on the substrate 32. The bottom of the positioning spikes 35 passes through the first porous metal layer 321 and is connected to the first solid metal layer 322. The positioning spikes 35 can provide positioning during the installation of the wrist joint prosthesis, and can prevent the movement between the interphalangeal joints during drilling from causing instability. At the same time, it can reduce the positioning effect of the side plates and enable the side plates to play a greater fixing role. The positioning spikes 35 are convenient for implantation and positioning, and can prevent the movement between the interphalangeal joints during drilling from causing instability. The positioning spikes 35 and the first solid metal layer 322 are an integral body, that is, the structural strength of the positioning spikes 35 is better.

[0053] As Figure 3 shown, in this 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 that are arranged from top to bottom. The third porous metal layer 331 is in contact with the bone retained after 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 play a certain supporting role in the wrist joint prosthesis.

[0054] As Figure 1 and Figure 3As shown, in this embodiment, the wrist joint prosthesis further includes 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 articular liner 20 is made of a polymer material. The first locking screw 41 and the second locking screw 42 function to fix the wrist joint prosthesis. The first locking screw 41 and the second locking screw 42 are non-parallel structures, that is, the extension lines where the first locking screw 41 and the second locking screw 42 are located intersect, which can make the connection between the upper part (the articular liner 20, the plate body 30) of the wrist joint prosthesis and the bone retained after osteotomy stable and not easy to fall off, and can prevent the first locking screw 41 and the second locking screw 42 from being driven into the metacarpal bone. The polymer selected for the articular liner 20 is a material with approximate hardness and elasticity to natural physiological cartilage of the human body, preferably polyurethane TPU material, polyvinyl alcohol gel, polylactic acid, etc. This polymer has good ductility, fracture strength, wear resistance, and biocompatibility, so it can achieve good bonding with the porous trabecular metal layer to ensure the overall performance of the long-term implantation of the prosthesis.

[0055] As Figure 1 shown, in this embodiment, the main connection between the substrate and the patient's hand bone is the first locking screw 41 and the second locking screw 42, and the positioning spikes 35 mainly play a positioning role. Therefore, the positioning spikes 35 can be set relatively short and should not be driven into the metacarpal bone as much as possible. Since both the first locking screw 41 and the second locking screw 42 are inclined, they will not be driven into the metacarpal bone either. Compared with the wrist joint prosthesis in the prior art that is driven into the metacarpal bone, the solution of this embodiment is safer and less harmful to the patient.

[0056] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by orientation words such as "front, back, up, down, left, right", "horizontal, vertical, perpendicular, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description. Without contrary explanation, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, so it cannot be understood as a limitation on the protection scope of the present invention; the orientation words "inside, outside" refer to the inside and outside relative to the contour of each component itself.

[0057] For ease of description, spatial relative terms, such as "above", "over", "on the upper surface", "upper", etc., may be used herein to describe the spatial positional relationship of one device or feature to other devices or features as shown in the figures. It should be understood that the spatial 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 inverted, a device described as "above" or "over" other devices or structures will then be positioned "below" or "under" the other devices or structures. Thus, the exemplary term "above" can include both the orientations of "above" and "below". The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding interpretations of the spatial relative descriptions used herein will be made.

[0058] In addition, it should be noted that the use of terms such as "first" and "second" to define components is only for the convenience of differentiating the corresponding components. Without additional statements, the above terms have no special meanings, and thus should not be construed as limiting the scope of protection of the present invention.

[0059] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A wrist joint prosthesis, characterized in that, it includes: a radius component (10) having an articular surface (11) and a ball shaft (12) provided on the articular surface (11); an articular liner (20) movably connected to the radius component (10), the bottom of the articular liner (20) cooperating with the articular surface (11), a limiting groove being provided on the articular liner (20), the limiting groove including a first limiting groove (21) and a second limiting groove (22) that communicate with each other, the first limiting groove (21) extending along a first direction (S1), and the second limiting groove (22) extending along a second direction (S2); a plate body (30) connected to a side of the articular liner (20) away from the radius component (10), a connection hole being provided on the plate body (30); wherein, the ball shaft (12) is located in the limiting groove, and the articular liner (20) can move relative to the radius component (10) along the first direction (S1) under the cooperation of the first limiting groove (21) and the ball shaft (12), and the articular liner (20) can move relative to the radius component (10) along the second direction (S2) under the cooperation of the second limiting groove (22) and the ball shaft (12); the ball shaft (12) includes a ball body (121) and a shaft portion (122) provided between the ball body (121) and the articular 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 limiting groove (21) includes a first groove section (211) that cooperates with the shaft portion (122) and a second groove section (212) that cooperates with the ball body (121), a groove width of the first groove section (211) is smaller than a groove width of the second groove section (212), and an opening of the first limiting groove (21) is formed on the first groove section (211); the second limiting groove (22) includes a third groove section (221) that cooperates with the shaft portion (122) and a fourth groove section (222) that cooperates 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 an opening of the second limiting groove (22) is formed on the third groove section (221); the ball body (121) has a top surface, and the top surface is a flat surface (1211).

2. The wrist joint prosthesis according to claim 1, characterized in that, the articular surface (11) is in a concave spherical shape, the first direction (S1) is a first arc direction, a center of a circle where the first arc direction is located coincides with a center of a sphere of the spherical surface where the articular surface (11) is located, the second direction (S2) is a second arc direction, and a center of a circle where the second arc direction is located coincides with the center of the sphere of the spherical surface where the articular surface (11) is located.

3. The wrist joint prosthesis according to claim 1, characterized in that, The plate body (30) includes a base plate (32) and a first side plate (33) disposed outside the base plate (32). A first obtuse angle (A) is formed between the first side plate (33) and the base plate (32). The connecting hole includes a first connecting hole (311) disposed on the first side plate (33).

4. The wrist joint prosthesis according to claim 3, wherein, the plate body (30) further includes a second side plate (34) disposed inside the base plate (32). A second obtuse angle (B) is formed between the second side plate (34) and the base plate (32). The connecting hole further includes a second connecting hole (312) disposed on the second side plate (34). The angle of the second obtuse angle (B) is greater than or equal to the angle of the first obtuse angle (A).

5. The wrist joint prosthesis according to claim 3, wherein, the base plate (32) includes a first porous metal layer (321), a first solid metal layer (322), and a second porous metal layer (323) sequentially arranged from top to bottom. The pore diameter of the first porous metal layer (321) is smaller than the pore diameter of the second porous metal layer (323).

6. The wrist joint prosthesis according to claim 5, wherein, the plate body (30) further includes a positioning spike (35) disposed on the base plate (32). The bottom of the positioning spike (35) passes through the first porous metal layer (321) and is connected to the first solid metal layer (322).

7. The wrist joint prosthesis according to claim 4, wherein, 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.

8. The wrist joint prosthesis according to claim 4, wherein, the wrist joint prosthesis further includes a first locking screw (41) disposed in the first connecting hole (311) and a second locking screw (42) disposed in the second connecting hole (312). The joint liner (20) is made of a polymer material.

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