Wrist joint prosthesis

Abstract

The wrist joint prosthesis comprises a carpal bone holder and a radius prosthesis, one of the carpal bone holder and the radius prosthesis is provided with a wrist joint convex, and the other is provided with a wrist joint concave, the wrist joint convex and the wrist joint concave are matched to make the carpal bone holder and the radius prosthesis movably abut together; wherein, the side of the carpal bone holder, which is opposite to the radius prosthesis, has an abutting surface, the abutting surface is used to abut against a carpal bone side bone cutting surface, the abutting surface comprises a platform surface and a first slope surface and a second slope surface connected to opposite edges of the platform surface, the included angle A between the first slope surface and the platform surface ranges from 15° to 35°, and the included angle B between the second slope surface and the platform surface ranges from 25° to 45°. The wrist joint prosthesis, the overall shape of the abutting surface of the carpal bone holder is similar to the shape of the bone surface at the place where the carpal bone is used to install the carpal bone holder, so that when the carpal bone is cut to form a bone cutting surface which is adapted to the abutting surface, the bone cutting amount of the carpal bone can be reduced as much as possible.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, in particular to a wrist joint prosthesis. BACKGROUND

[0002] The wrist joint is one of the most flexible and important joints in the human body. For the treatment of serious diseases such as traumatic, degenerative wrist arthritis, rheumatoid wrist arthritis, and severe damage, most of the previous treatments are mainly wrist fusion. With the development of medicine and technology and the urgent hope of patients to solve the pain while preserving the activity function of the wrist joint, total wrist arthroplasty is increasingly applied to the treatment of wrist joints.

[0003] The wrist joint prosthesis used in total wrist arthroplasty includes a carpal bone prosthesis and a radius prosthesis. In the current wrist joint prosthesis, the bionic property of the carpal bone prosthesis is poor, and a high bone cutting amount is required for the carpal bone, which easily affects the functional recovery effect of the wrist joint. SUMMARY

[0004] Therefore, the present application provides a wrist joint prosthesis, which effectively solves the technical problem of high bone cutting amount on the carpal side.

[0005] The wrist joint prosthesis provided by the present application includes a carpal bone holder and a radius prosthesis. One of the carpal bone holder and the radius prosthesis is provided with a wrist joint convex, and the other is provided with a wrist joint concave. The wrist joint convex and the wrist joint concave are matched to make the carpal bone holder and the radius prosthesis abut together. The side of the carpal bone holder opposite to the radius prosthesis has an abutting surface, which is used to abut against the carpal bone cutting surface. The abutting surface includes a platform surface and a first slope surface and a second slope surface connected to the opposite edges of the platform surface. The included angle A between the first slope surface and the platform surface is in the range of 15°-35°, and the included angle B between the second slope surface and the platform surface is in the range of 25°-45°.

[0006] In one embodiment, the wrist joint convex has a spherical surface or an ellipsoidal surface, and the wrist joint concave has a spherical surface or an ellipsoidal surface.

[0007] In one embodiment, the carpal bone holder is an integral structure.

[0008] In one embodiment, the included angle C between the first slope surface and the second slope surface is in the range of 120°-140°.

[0009] In one embodiment, the platform surface is provided with a fixing member for insertion into the capitulum.

[0010] In one embodiment, the surface of the abutting surface and / or the fixing member is provided with a porous coating.

[0011] In one of the embodiments, the carpal bone holder comprises a main body part, a platform surface on the main body part, a first slope surface on one of the side wings, a second slope surface on the other side wing, and a nail hole on each of the two side wings.

[0012] In one of the embodiments, the angle between the hole axis of at least one of the nail holes on the two side wings and the platform surface is an acute angle; and / or, the two side wings are in the form of a sheet and are integrally formed with the main body part.

[0013] In one of the embodiments, the radius of curvature of the wrist joint convex is smaller than the radius of curvature of the wrist joint concave.

[0014] In one of the embodiments, the side of the carpal bone holder facing away from the abutting surface is formed with an ellipsoidal concave surface, the ellipsoidal concave surface forms the wrist joint concave; the radius bone prosthesis comprises a fixedly connected ball head part and a handle part, the side surface of the ball head part facing away from the handle part is an ellipsoidal convex surface, and the ellipsoidal convex surface forms the wrist joint convex.

[0015] In one of the embodiments, the carpal bone holder is a metal integrally formed structure, and the ball head part is made of plastic.

[0016] In one of the embodiments, the wrist joint prosthesis comprises at least two ball head parts with different thicknesses, and the ball head part is detachably connected with the handle part, wherein the thickness of the ball head part is the vertical distance from the apex of the ellipsoidal convex surface to the bottom surface of the ball head part.

[0017] In one of the embodiments, the wrist joint prosthesis comprises at least two carpal bone holders with different thicknesses, and the thickness of the carpal bone holder is the vertical distance from the apex of the ellipsoidal concave surface to the platform surface.

[0018] The wrist joint prosthesis provided by the present application comprises a carpal bone holder and a radius bone prosthesis, one of the carpal bone holder and the radius bone prosthesis is provided with a wrist joint convex, and the other is provided with a wrist joint concave, the wrist joint convex and the wrist joint concave are matched to enable the carpal bone holder and the radius bone prosthesis to abut and move relative to each other, thereby realizing the rotation function of the wrist joint prosthesis; the abutting surface of the carpal bone holder for abutting against the bone surface of the carpal bone is designed in a bionic manner similar to the bone surface of the carpal bone, i.e., the abutting surface comprises a platform surface and a first slope surface and a second slope surface connected to the opposite edges of the platform surface, the included angle A between the first slope surface and the platform surface is in the range of 15°-35°, and the included angle B between the second slope surface and the platform surface is in the range of 25°-45°, so that the overall shape of the abutting surface of the carpal bone holder is similar to the shape of the bone surface of the carpal bone at the position where the carpal bone holder is installed, thereby minimizing the amount of bone cutting of the carpal bone when the carpal bone is cut to form a bone surface suitable for the abutting surface. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the wrist joint prosthesis in one embodiment;

[0021] Figure 2 for Figure 1 The diagram shows the structure of the wrist bone support of the wrist joint prosthesis;

[0022] Figure 3 A schematic diagram of the cross-sectional structure of the wrist bone support in a wrist joint prosthesis according to one embodiment.

[0023] Figure 4 A schematic diagram of the wrist bone support of a wrist joint prosthesis according to another embodiment;

[0024] Figure 5 for Figure 4 A schematic diagram of the cross-sectional structure of the wrist bone support of the wrist joint prosthesis is shown.

[0025] Figure 6 for Figure 1 The diagram shows a cross-sectional view of the wrist joint prosthesis along line II.

[0026] Figure 7 for Figure 6 A magnified schematic diagram of the local structure within the frame lines;

[0027] Figure 8 Another cross-sectional structural diagram of a wrist joint prosthesis according to one embodiment;

[0028] Figure 9 for Figure 8 A magnified schematic diagram of the local structure within the frame lines;

[0029] Figure 10 A structural schematic diagram of a wrist joint prosthesis according to one embodiment;

[0030] Figure 11 A schematic diagram of the structure of the ball head of the radial prosthesis in one embodiment of a wrist joint prosthesis;

[0031] Figure 12 This is a schematic diagram of the radial prosthesis of a wrist joint prosthesis according to one embodiment. Detailed Implementation

[0032] In order to make the above objectives, features and advantages of the present application more clear and comprehensible, specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. It will be apparent, however, to one skilled in the art that the present application can be practiced without using these specific details. In other instances, well-known methods have not been described in detail in order to avoid unnecessarily obscuring the present application. Therefore, the specific embodiments described herein are not intended to limit the present application, but rather, the present application is to cover all modifications and alternatives falling within the scope of the present application.

[0033] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only used for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0034] In addition, the terms "first", "second", "third", etc. are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second", etc. can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise explicitly specified and limited.

[0035] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0036] In the present application, unless otherwise explicitly specified and limited, a first feature is "on" or "under" a second feature can mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature is "above", "over" and "on top of" the second feature can mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature. The first feature is "under", "below" and "underneath" the second feature can mean that the first feature is directly under or obliquely under the second feature, or simply means that the first feature is horizontally lower than the second feature.

[0037] It should be noted that when an element is referred to as being "fixed to" or "set to" another element, it can be directly on the other element or there can be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there can be an intermediate element. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation.

[0038] Referring to Figure 1 and Figure 6 The present application provides a wrist joint prosthesis 100, which comprises a carpal bone holder 10 and a radius prosthesis 20.

[0039] One of the carpal bone holder 10 and the radius prosthesis 20 is provided with a wrist joint convex 21a, and the other is provided with a wrist joint concave 11e. The wrist joint convex 21a and the wrist joint concave 11e are matched to make the carpal bone holder 10 and the radius prosthesis 20 moveably abut together. Thus, after the carpal bone holder 10 is fixed to the carpal bone and the radius prosthesis 20 is fixed to the radius, the matching between the carpal bone holder 10 and the radius prosthesis 20 can replace the function of the wrist joint, so as to achieve the purpose of replacing the wrist joint. The wrist joint convex 21a and the wrist joint concave 11e can be spherical or ellipsoidal surfaces, or other surfaces that can slide relative to each other, such as arc-shaped curved surfaces, etc. However, from the perspective of multidirectional rotation, spherical or ellipsoidal surfaces are preferred, and ellipsoidal surfaces are more preferred, because ellipsoidal surfaces are more consistent with the anatomical shape of the wrist joint.

[0040] The side of the carpal bone holder 10 opposite to the radius prosthesis 20 is provided with an abutting surface 11, which is used to abut against a carpal bone side bone cutting surface. The carpal bone side bone cutting surface is a bone surface formed after a bone cutting operation is performed on the carpal bone to adapt to the installation of the carpal bone holder 10. In this embodiment, before the carpal bone holder 10 is installed on the carpal bone, a bone cutting operation is performed on the carpal bone to form a carpal bone side bone cutting surface that is adapted to the abutting surface 11, so that when the carpal bone holder 10 is installed on the carpal bone, the overall shape of the carpal bone side bone cutting surface is adapted to the abutting surface 11 of the carpal bone holder 10, so that the two are in contact with each other, and the carpal bone holder 10 is fixed to the carpal bone through the screw 100a (see Figure 1The connectors are firmly connected together.

[0041] As Figure 2 In this embodiment, the abutting surface 11 includes a platform surface 11a, a first slope surface 11b and a second slope surface 11c. The first slope surface 11b and the second slope surface 11c are connected at opposite edges of the platform surface 11a. The angle A between the first slope surface 11b and the platform surface 11a is in the range of 15° to 35°, and the angle B between the second slope surface 11c and the platform surface 11a is in the range of 25° to 45°. It should be noted that the angles between the first slope surface 11b and the platform surface 11a and between the second slope surface 11c and the platform surface 11a are actually obtuse angles, but for the convenience of description, the angle between the first slope surface 11b and the extension line of the platform surface 11a is taken as the angle A, and the angle between the second slope surface 11c and the extension line of the platform surface 11a is taken as the angle B. Figure 2 or Figure 5 as shown.

[0042] According to the inventors' research on the anatomical morphology of the wrist of Chinese patients, it is found that within the above numerical range, the abutting surface 11 composed of the first slope surface 11b, the platform surface 11a and the second slope surface 11c is similar to the bone surface of the carpal bone for mounting the carpal bone holder 10, so that when the carpal bone is cut to form a carpal bone side cut surface for mounting the carpal bone holder 10, the amount of bone cutting can be minimized.

[0043] Specifically, when the carpal bone holder 10 is mounted to the carpal bone side cut surface, the carpal bone side cut surface is adapted to the abutting surface 11 of the carpal bone holder 10. To be exact, the cut surface of the carpal bone for mounting the carpal bone holder 10 is adapted to the platform surface 11a, the first slope surface 11b and the second slope surface 11c of the abutting surface 11. Therefore, when the wrist joint replacement surgery is performed using the carpal bone holder 10 with a similar bone surface of the carpal bone, only three cut lines similar to the bone surface of the carpal bone are needed to cut the carpal bone to form a cut surface with a flat bottom surface and two inclined side surfaces, so that a cut surface adapted to the abutting surface 11 of the carpal bone holder 10 can be obtained. In this cutting operation, the trend of the cutting tool (i.e. the extension direction of the cut line) when cutting the carpal bone is similar to the shape of the bone surface of the carpal bone, which can minimize the amount of bone cutting.

[0044] Since the platform surface 11a between the first slope surface 11b and the second slope surface 11c of the abutting surface 11 of the carpal bone holder 10 is relatively low, the position of the cut surface of the carpal bone corresponding to the platform surface 11a is relatively close to the radius, that is, the corresponding cut height is relatively small, so as to minimize the amount of bone cutting, and the first slope surface 11b and the second slope surface 11c are fixed with the corresponding cut surface of the carpal bone, which can improve the mounting stability of the carpal bone holder 10 on the carpal bone.

[0045] It should be noted that the angle A between the first slope surface 11b and the platform surface 11a is in the range of 15°-35°, for example, it can be 15°, 20°, 25°, 30° or 35°, preferably 25°-35°. The angle B between the second slope surface 11c and the platform surface 11a is in the range of 25°-45°, for example, 25°, 30°, 35°, 40° or 45°, preferably 30°-45°. The wrist bone holder 10 of this structure, because the overall shape of the abutting surface 11 formed thereby is adapted to the shape of the bone surface at the position where the wrist bone needs to be cut, thus in the operation of cutting the wrist bone to form a cut surface adapted to the abutting surface 11, the amount of cutting can be reduced as much as possible.

[0046] In combination Figure 2 As shown, preferably the sum of the angle A and the angle B is in the range of 40°-60°, that is, it satisfies 40°≤∠A+∠B≤60°, that is, the angle C between the first slope surface 11b and the second slope surface 11c is in the range of 120°-140° (the angle C is complementary to the angle A+angle B). Under this angle range, the overall angle design of the first slope surface 11b and the second slope surface 11c is closer to the anatomical shape of the wrist bone at the wrist joint, thus it is beneficial to reduce the amount of cutting in the cutting operation to adapt to the installation of the wrist bone holder 10. At the same time, through this structural arrangement, the contact surface with the cut wrist bone can be effectively increased by using the first slope surface 11b and the second slope surface 11c, thus the connection stability of the wrist bone holder 10 and the wrist bone is improved.

[0047] For the convenience of understanding, the structure of the wrist joint prosthesis 100 will be further described below by taking the example that the wrist joint convex 21a is formed on the radius prosthesis 20 and the wrist joint socket 11e is formed on the wrist bone holder 10. The inventor has found through a large number of researches that compared with the case that the wrist joint convex 21a is formed on the wrist bone holder 10, the structure that the wrist joint convex 21a is formed on the radius prosthesis 20 is more beneficial to the stability of the wrist joint, which is presumably due to the fact that the wrist bone side is the moving side and the radius side is the relatively stationary side, and the concave wrist bone side moves more stably on the convex radius side.

[0048] In combination Figure 5 As shown, the side of the wrist bone holder 10 away from the abutting surface 11 is formed with an ellipsoidal concave surface, and the ellipsoidal concave surface forms the wrist joint socket 11e. In combination Figure 6 And Figure 7 As shown, the radius prosthesis 20 includes a fixedly connected ball head part 21 and a handle part 22, and the surface of the ball head part 21 away from the handle part 22 is an ellipsoidal convex surface, and the ellipsoidal convex surface forms the wrist joint convex 21a. Thus, by using the contact cooperation of the ellipsoidal convex surface and the ellipsoidal concave surface, the rotation requirement of the wrist bone holder 10 and the radius prosthesis 20 with each other is met.

[0049] In some embodiments, the carpal bone tray 10 is a metal one-piece structure, and the ball head 21 is made of plastic. In this way, a relatively smooth friction interface can be formed between the ball head and the carpal bone tray 10 at the contact position therebetween. The friction between different materials is quiet, and the problem of metal debris caused by the metal-metal interface is avoided, thereby improving the use experience and safety of the wrist joint prosthesis 100. In this structure, the carpal bone tray 10 is a one-piece structure, thereby reducing the risk of assembly failure, effectively improving the functional recovery effect of the wrist joint, and reducing the overall cost of the wrist joint prosthesis.

[0050] Specifically, in the prior art wrist joint prosthesis, the ball head and the stem of the radius prosthesis are both made of metal. In order to ensure the bonding strength, the part of the carpal bone tray that is combined with the carpal bone is also made of metal. Therefore, in order to form a metal-plastic friction interface, the part of the carpal bone tray that contacts the radius prosthesis can only be made of plastic. However, due to the structural characteristics of the carpal bone tray and the fact that the carpal bone tray is the moving side, the risk of assembly failure of the metal and plastic parts is high, and the manufacturing process is complex and costly. In the wrist joint prosthesis of the present application, the carpal bone tray 10 is a one-piece metal structure, the ball head 21 of the radius prosthesis 20 is made of plastic, and the stem 22 is made of metal. This not only ensures the metal-plastic friction interface, but also ensures the bonding strength of the wrist joint prosthesis and the autologous bone, and avoids the assembly failure problem of the metal and plastic parts of the carpal bone tray. The inventors have found through extensive research that the assembly failure problem of the ball head 21 and the stem 22 of the radius prosthesis 20 is much smaller than that of the carpal bone tray, because the radius side is the stationary side. Therefore, this design improves the reliability of the wrist joint prosthesis as a whole, while controlling the production cost.

[0051] Again referring to Figure 2 As shown, the platform surface 11a is provided with a fixing member 104 for insertion into the head bone to fix the carpal bone tray 10 to the carpal bone. The fixing member 104 can be a columnar, pin-shaped or tapered rod structure, etc., as long as it can be fixed to the carpal bone.

[0052] The abutting surface 11 is provided with a porous coating 11d, and the porosity and elastic modulus of the porous coating 11d are preferably consistent with those of the carpal bone. In this way, when the abutting surface 11 contacts the carpal bone side osteotomy surface, the bone tissue of the carpal bone can better grow in, thereby more stably fixing the carpal bone tray 10.

[0053] In some embodiments, in combination Figure 3 As shown, the abutting surface 11 and the surface of the fixing member 104 are both provided with a porous coating 11d, and the porosity and elastic modulus of the porous coating 11d are preferably consistent with those of the carpal bone. This is conducive to the better growth of the bone tissue of the carpal bone, thereby more stably fixing the carpal bone tray 10.

[0054] The porous coating 11d is sintered from metal particles or ceramic particles, and the process is simple and easy to manufacture.

[0055] After the carpal bone holder 10 is installed to the carpal bone by the fixing member 104, the platform surface 11a corresponds to the bottom plane of the cut bone of the carpal bone, and the first slope surface 11b and the second slope surface 11c correspond to the two side slopes of the cut bone of the carpal bone, respectively, so as to further strengthen the connection stability of the carpal bone holder 10 and the carpal bone by the connecting member passing through the first slope surface 11b and the second slope surface 11c.

[0056] For example, as shown in Figures 3 to 5 The carpal bone holder 10 includes a main body part 101 and two side wing parts 102, the platform surface 11a is located on the main body part 101, the first slope surface 11b is located on one of the two side wing parts 102, the second slope surface 11c is located on the other side wing part 102, and the two side wing parts 102 are both provided with screw holes 103. As shown in Figure 8 and Figure 10 The screw holes 103 are adapted to the passing of the screws 100a, so that the screws 100a can fix the two side wing parts 102 to the carpal bone, and strengthen the installation stability of the carpal bone holder 10. The screw holes 103 can be cancellous bone screw holes 103, that is, the screws 100a are directly threadedly locked to the carpal bone without generating thread locking force between the screws 100a and the screw holes 103. The screw holes 103 can also be locking screw holes 103, so that the screws 100a not only have the thread locking force between the screws 100a and the carpal bone, but also threadedly cooperate with the screw holes 103, thereby strengthening the connection stability of the corresponding side wing part 102 and the carpal bone.

[0057] Among the screw holes 103 on the two side wing parts 102, the included angle between the hole axis of at least one screw hole 103 and the platform surface 11a is an acute angle. For example, the included angle between the hole axis of the screw hole 103 on one of the two side wing parts 102 and the platform surface 11a is 45°-85°. The included angle between the hole axis of the screw hole 103 on the other side wing part 102 and the platform surface 11a is 90°.

[0058] In some embodiments, as shown in Figure 5 The hole axes of the screw holes 103 on the two side wing parts 102 are both acute angles with the platform surface 11a. As shown in Figure 8 With this structure, after the corresponding screw hole 103 penetrates the screw 100a, the screws 100a on the two side wing parts 102 cross each other, forming a cross-locked structure, that is, the screws 100a on the two side wing parts 102 converge inward relative to the platform surface 11a, at this time, the screws 100a on the two side wing parts 102 are not parallel to each other, and the carpal bone holder 10 is more stably installed to the carpal bone.

[0059] It should be noted that the hole axes of the two holes 103 on the two side wings 102 can be coplanar or not coplanar, that is, the extension direction of the screw 100a passing through the two holes 103 on the two side wings 102 can be in the same plane or not in the same plane.

[0060] In some embodiments, the two side wings 102 are in the form of a sheet and are integrally formed with the main body 101. Through this structural arrangement, when the side wings 102 are stably connected with the carpal bone by passing the screw 100a through the holes 103 on the side wings 102, the sheet-shaped side wings 102 can as much as possible leave an operation space on the side close to the radius to form a good avoiding position, so as to perform a locking operation on the screw 100a, or when it is necessary to change the locking position of the screw 100a on the carpal bone, the screw 100a can be conveniently disassembled.

[0061] It should be noted that the number of holes 103 on each side wing 102 can be multiple, for example, as shown in Figure 4 and Figure 5 , each side wing 102 is provided with two holes 103, that is, two screws 100a can be passed through the two holes 103 of the side wing 102 respectively, so as to improve the connection stability of the side wing 102 with the carpal bone. In other embodiments, the number of holes 103 on each side wing 102 can also be more than two, so as to further adapt to the fastening and installation needs of more screws 100a on the carpal bone holder 10, and the number of holes 103 is not limited here.

[0062] As shown in Figures 6 to 9 , the radius of curvature of the wrist joint convexity 21a is smaller than the radius of curvature of the wrist joint socket 11e, so that the wrist bone holder 10 and the radius prosthesis 20 can be flexibly rotated, so that the wrist joint prosthesis 100 can realize the rotation movement at the wrist joint.

[0063] In some embodiments, the wrist joint prosthesis 100 includes at least two ball head portions 21 with different thicknesses. As shown in Figure 11 and Figure 12 , the ball head portion 21 is detachably connected with the handle portion 22, so as to adapt to the implantation needs of the wrist joint prosthesis 100 when the bone cutting thickness is different. Among them, the thickness of the ball head portion 21 is the vertical distance L from the vertex of the ellipsoidal convex surface (the point on the ellipsoidal convex surface with the farthest vertical distance from the bottom surface) to the bottom surface of the ball head portion (the plane on the side of the ball head portion 21 away from the ellipsoidal convex surface, that is, the plane contacting the handle portion 22).

[0064] Correspondingly, the model of the carpal bone holder 10 can also have multiple possibilities to meet the replacement needs of different wrist joints. Specifically, as shown in Figure 3 and Figure 5The vertical distance H from the top point of the ellipsoid concave surface to the platform surface 11a is the thickness of the carpal bone holder 10, and the thickness of the carpal bone holder 10 is used to represent the model of the carpal bone holder 10, that is, the carpal bone holders 10 of different models have different thicknesses. When the carpal bone holders 10 with different thicknesses are used, the eccentricity of the relative movement of the radius and the carpal bone holder 10 in the wrist joint prosthesis 100 is different, and then the structure meets the needs of wrist joint replacement of different patients.

[0065] When the wrist joint prosthesis 100 is used for wrist joint replacement, first, the carpal bone side is cut to form a carpal bone side cut surface that matches the abutting surface 11 of the carpal bone holder 10, that is, the shape of the carpal bone side cut surface corresponds to the shape of the abutting surface 11 of the carpal bone holder 10. After the carpal bone side cutting is completed, the carpal bone holder 10 is installed on the carpal bone, so that the fixing member 104 on the platform surface 11a of the carpal bone holder 10 is inserted into the capitate bone or the capitate bone and the third metacarpal bone. In the embodiment in which the surface of the platform surface 11a of the carpal bone holder 10 has a porous coating 11d, after the carpal bone holder 10 is fixed to the carpal bone, the porous coating 11d on the platform surface 11a of the carpal bone holder 10 contacts the carpal bone cut surface. The carpal bone holder 10 is fixed to the carpal bone by screwing the screws 100a from the nail holes 103 on the two sides 102, and since the nail holes 103 are at an acute angle relative to the platform surface 11a, the directions in which the two screws 100a are driven are interlocked, so as to improve the fixing effect of the carpal bone holder 10. Then, the radius side is processed, and the ball head 21 and the handle 22 of the radius prosthesis 20 are installed. During this process, different thicknesses of the ball head 21 can be selected according to the amount of cutting.

[0066] It should be noted that during the matching process of the wrist joint prosthesis 100, different thicknesses of the carpal bone holder 10 can also be selected to adjust the eccentricity of the carpal joint. Finally, the ball head 21 is assembled into the ellipsoid concave surface on the carpal bone holder 10, that is, the cooperation of the wrist joint convex 21a and the wrist joint socket 11e is completed, and the wrist joint prosthesis 100 is implanted.

[0067] The technical features of the above-described embodiments can be combined in any manner. To make the description concise, all possible combinations of the technical features in the above-described embodiments are not described, but as long as the combinations of the technical features do not exist, they should be considered as within the scope of the present disclosure.

[0068] The above-described embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it should not be understood as limiting the scope of the patent. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A wrist prosthesis, characterized in that The wrist bone holder and the radius prosthesis are integrally formed, one of the wrist bone holder and the radius prosthesis is provided with a wrist joint convex, and the other is provided with a wrist joint concave, the wrist joint convex and the wrist joint concave are matched, so that the wrist bone holder and the radius prosthesis are movably connected together, the radius prosthesis includes a detachable ball head and a handle, the surface of the side of the ball head away from the handle is an ellipsoidal convex, the ellipsoidal convex forms the wrist joint convex, the wrist joint prosthesis includes at least two ball heads with different thicknesses and at least two wrist bone holders with different thicknesses, the thickness of the ball head is the vertical distance from the top of the ellipsoidal convex to the bottom of the ball head, the thickness of the wrist bone holder is the vertical distance from the top of the ellipsoidal concave to the platform, different thicknesses of the ball head are selected according to the amount of bone cutting, and different thicknesses of the wrist bone holder are selected according to requirements to adjust the eccentricity when the radius prosthesis and the wrist bone holder in the wrist joint prosthesis relatively move.

2. The wrist prosthesis of claim 1, wherein, The angle A between the first slope surface and the platform is 15° or 20°.

3. The wrist prosthesis of claim 1, wherein, The angle B between the second slope surface and the platform is 30°-45°.

4. The wrist prosthesis of claim 1, wherein, The fixing member is columnar or rod-shaped with a taper.

5. The wrist prosthesis of claim 1, wherein, The abutting surface is provided with a porous coating.

6. The wrist prosthesis of claim 1, wherein, The angle between the hole axis of at least one of the screw holes in the two side wings and the platform is an acute angle.

7. The wrist prosthesis of claim 1 or 6, wherein, The two side wings are sheet-shaped and integrally formed with the main body.

8. The wrist prosthesis of claim 1, wherein, The wrist bone holder is integrally formed of metal, and the ball head is made of plastic.

9. The wrist prosthesis of claim 6, wherein, The angle between the hole axis of the screw hole in one of the side wings and the platform is 45°-85°, and the angle between the hole axis of the screw hole in the other side wing and the platform is 90°.

10. The wrist prosthesis of claim 6, wherein, The hole axes of the screw holes in the two side wings are coplanar.

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