CN215019770U

CN215019770U - Wrist joint radius prosthesis

Info

Publication number: CN215019770U
Application number: CN202023029431.0U
Authority: CN
Inventors: 孙延东; 周思远; 黄有军
Original assignee: Suzhou Moving Funeng Medical Technology Co ltd
Current assignee: Suzhou Weichuang Touched Funeng Medical Technology Co ltd
Priority date: 2020-12-16
Filing date: 2020-12-16
Publication date: 2021-12-07
Anticipated expiration: 2030-12-16

Abstract

The utility model provides a wrist joint radius false body, including stalk portion and platform portion, platform portion has the bottom surface, the stalk portion extends along the direction of perpendicular to bottom surface, the stalk portion is the taper, relative big head end and microcephaly end have, big head end is connected with the bottom surface, be equipped with the first boundary line parallel with the bottom surface between big head end and the microcephaly end, in the normal position projection, the width of first boundary line is LA, big head end and bottom surface juncture's width is LB, the vertical distance of first boundary line to platform portion's bottom surface is HC, the microcephaly end of stalk portion is HD to platform portion's bottom surface's vertical distance, wherein, 0.4 is less than or equal to LA/LB less than or equal to 0.6, 0.5 is less than or equal to HC HD less than or equal to 0.7. The utility model provides a wrist joint radius false body, the adherence of stalk portion and radius medullary cavity is good, effectively improves the stability of being connected of wrist joint radius false body and radius to reduce the emergence of dislocation phenomenon.

Description

Wrist joint radius prosthesis

Technical Field

The utility model relates to the technical field of medical equipment, especially relate to a wrist joint radius false body.

Background

The wrist joint is one of the most flexible and important joints of the human body, most of the treatments for traumatic, degenerative and rheumatoid arthritis and other diseases are mainly performed by wrist joint fusion, and the total wrist joint replacement is increasingly applied to wrist joint treatment along with the development of medical science and technology and the urgent desire of patients to solve pain and retain the activity function of the wrist joint.

However, the existing wrist joint and radius prosthesis has poor installation stability and is easy to dislocate.

SUMMERY OF THE UTILITY MODEL

Based on this, the utility model provides a wrist joint radius false body effectively solves the technical problem of poor stability, easy dislocation.

The utility model provides a pair of wrist joint radius false body, including stalk portion and platform portion, platform portion has the bottom surface, the stalk portion is along the perpendicular to the direction of bottom surface extends, the stalk portion is the taper, has relative big head end and microcephaly end, big head end with the bottom surface is connected, big head end with be equipped with between the microcephaly end with the parallel first boundary line of bottom surface, in normal position projection, the width of first boundary line is LA, big head end with the width of bottom surface juncture is LB, first boundary line arrives the vertical distance of the bottom surface of platform portion is HC, the microcephaly end of stalk portion arrives the vertical distance of the bottom surface of platform portion is HD, wherein, 0.4 is less than or equal to LA/is less than or equal to LB 0.6, 0.5 is less than or equal to HC HD is less than or equal to 0.7.

In one embodiment, the outer surface of the shank between the big end and the first boundary line is provided with a porous coating.

In one embodiment, the diameter of the small end is greater than or equal to 2 mm.

In one embodiment, an ellipsoidal joint surface is formed on one side of the platform part, which faces away from the bottom surface, the length of a short axis of a top view projection of the ellipsoidal joint surface is W, the length of a long axis of the top view projection of the ellipsoidal joint surface is L, and W/L is more than or equal to 0.5 and less than or equal to 0.8.

In one embodiment, an included angle a between a major axis of the top view projection of the ellipsoidal joint surface and the bottom surface ranges from 10 ° to 25 °, and/or an included angle B between a minor axis of the top view projection of the ellipsoidal joint surface and the bottom surface ranges from 0 ° to 10 °.

In one embodiment, in the orthographic projection, an included angle a1 between a lower tangent plane of the ellipsoidal joint surface and the bottom surface ranges from 10 ° to 25 °, and/or in the lateral projection, an included angle B1 between the lower tangent plane of the ellipsoidal joint surface and the bottom surface ranges from 0 ° to 10 °.

In one embodiment, the peripheral surface of the platform part and the side projection plane intersect at a first sideline and a second sideline, and the included angle C between the first sideline and the second sideline ranges from 5 ° to 15 °.

In one embodiment, an included angle D between the first side line and the normal of the bottom surface ranges from 15 ° to 25 °.

In one embodiment, the part of the platform part close to the bottom surface extends along the shank part along the radial direction relative to the big head end to form a flange, the two points with the largest distance in any two points on the outline of the flange are a first point and a second point, the distance between the first point and the second point defines the length ML of the flange, and the distance between the two points which are positioned on the outermost side on the outline of the flange in the vertical direction defines the width AP of the flange in the vertical direction of the connecting line of the first point and the second point, wherein, the AP/ML is more than or equal to 0.7 and more than or equal to 0.5 mm and more than or equal to 45 mm.

In one embodiment, the contour of the flange comprises a first convex arc section, a second convex arc section, a third convex arc section, a fourth convex arc section and a fifth concave arc section which are smoothly and adjacently connected in sequence, wherein the curvature radius R1 of the first convex arc section ranges from 7mm to 15mm, the curvature radius R2 of the second convex arc section ranges from 15mm to 30mm, and the curvature radius R5 of the fifth concave arc section ranges from-30 mm to-20 mm.

In one embodiment, a straight line section is connected between the third convex arc section and the fourth convex arc section, and both the third convex arc section and the fourth convex arc section are tangent to the straight line section.

In one embodiment, the bottom surface of the platform portion is provided with a porous structure layer, and the porous structure layer is connected with the porous coating layer.

The utility model provides a wrist joint radius false body, including stalk portion and platform portion, the stalk portion extends along the direction of perpendicular to bottom surface, wherein, the stalk portion is the taper, relative big head end and microcephaly end have, big head end is connected with the bottom surface, be equipped with the first boundary line parallel with the bottom surface between big head end and the microcephaly end, in the normal position projection, the width of first boundary line is LA, big head end and bottom surface juncture's width is LB, the vertical distance of first boundary line to platform portion's bottom surface is HC, the vertical distance of the microcephaly end of stalk portion to platform portion's bottom surface is HD, wherein, 0.4 is no less than LA/LB is no less than 0.6, 0.5 is no less than HC/HD is no less than 0.7, so that stalk portion and radius pulp cavity's adherence is good, effectively improve the stability of being connected of wrist joint radius false body and radius, in order to reduce the emergence of dislocation phenomenon.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, drawings of other embodiments can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic diagram illustrating the construction of an embodiment of a wrist joint radius prosthesis;

FIG. 2 is a schematic structural view of another embodiment of a wrist joint radius prosthesis;

FIG. 3 is a schematic structural view of a wrist-joint radial prosthesis according to yet another embodiment;

FIG. 4(a) is a schematic view illustrating a state in which a wrist joint radial prosthesis according to an embodiment is implanted in a radius;

FIG. 4(b) is a schematic view illustrating a state in which another embodiment of a wrist joint radial prosthesis is implanted in a radius;

FIG. 5 is a schematic view of an embodiment of a wrist joint radial prosthesis implanted in a radius, as viewed from the direction of the osteotomy plane;

FIG. 6 is a schematic view of a plurality of wrist joint radius prostheses of different sizes as implanted in the radius, viewed from the direction of the osteotomy plane, wherein the peripheral contour of the flange of each size of wrist joint radius prosthesis is schematically represented in the osteotomy plane of the same radius;

FIG. 7 is a schematic edge profile of an ellipsoidal joint surface of an embodiment of a wrist-joint radial prosthesis;

FIG. 8 is a schematic view of the wrist joint radius prosthesis in the wrist joint positioning piece according to an embodiment;

FIG. 9 is a schematic view of the structure of an embodiment of a wrist-joint radial prosthesis in a lateral wrist-joint plate.

Detailed Description

In order to make the above objects, features and advantages of the present invention more comprehensible, embodiments of the present invention are 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 invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, as those skilled in the art will be able to make similar modifications without departing from the spirit and scope of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like, indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplicity of 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, should not be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In the present application, unless expressly stated or limited otherwise, the first feature may be directly on or directly under the second feature or indirectly via intermediate members. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a unique embodiment.

Referring to fig. 1, the present invention provides a wrist joint radius prosthesis comprising a handle portion 10 and a platform portion 20.

The platform portion 20 is detachably connected to the shank portion 10 so that it is possible to flexibly fit different models of platform portions 20 or shank portions 10. The detachable connection between the two can be realized by adopting a snap fit mode, and the mode is convenient to disassemble and assemble, so that the matching efficiency of the platform part 20 and the handle part 10 is improved. For example, the shank 10 is provided with a sliding projection, the platform 20 is provided with a sliding groove which is slidably fitted with the sliding projection, and the platform 20 is restricted to the shank 10 in a direction perpendicular to the bottom surface 20a (i.e., an extending direction of a normal line of the bottom surface 20 a) by the fitting of the sliding projection and the sliding groove, and in this configuration, after the sliding projection and the sliding groove are slidably fitted, the platform 20 is pushed against the shank 10 in a direction parallel to the bottom surface 20a, so that the platform 20 can be quickly assembled to the shank 10. Accordingly, when it is desired to remove the platform portion 20 from the shank portion 10, it is merely necessary to push the platform portion 20 away from the shank portion 10 along the slide tabs.

As shown in fig. 2, the platform portion 20 is integrally formed with the handle portion 10, and this integral structure reduces the number of components, thereby facilitating implantation into the radius and providing better stability. When the platform part 20 and the handle part 10 are integrally formed, the process has a large selection space, and the wrist joint and radius prosthesis can be obtained by cutting and grinding materials, or can be processed by 3D printing.

In some embodiments, the material of the wrist joint radial prosthesis can adopt cobalt chromium molybdenum material, which not only has good wear resistance and corrosion resistance, but also has good biocompatibility.

In other embodiments, the handle 10 of the wrist-joint radial prosthesis may be of a titanium alloy material to facilitate processing by 3D printing.

Fig. 3 shows a projection of a wrist joint radius prosthesis in an orthotopic position, the so-called orthotopic position, which for a human wrist is the front side of the wrist, i.e. the palm is laid flat on a table top looking down on the orientation of the palm; for the radial prosthesis, this is the position in which its projected area is the largest, i.e. parallel to the bottom surface 20a and the widest width of the prosthesis is observed. The orientation perpendicular to the true position in the direction parallel to the bottom surface 20a is the lateral position, i.e., the orientation in which the face of the prosthesis having the narrowest width is observed.

The handle 10 is tapered (i.e., gradually widening or gradually narrowing from one end to the other in orthographic projection), having opposite large 10a and small 10b head ends. The platform part 20 is provided with a bottom surface 20a, the bottom surface 20a is approximately vertical to the handle part 10 and is connected with the big end 10a, a first boundary line 11a is arranged between the big end 10a and the small end 10b, the first boundary line 11a is parallel to the bottom surface 20a, in the orthographic projection, the width of the first boundary line 11a is LA, the width of the junction of the big end 10a and the bottom surface 20a of the handle part 10 is LB, the vertical distance from the first boundary line 11a to the bottom surface 20a of the platform part 20 is HC, the vertical distance from the end point of the small end 10b of the handle part 10 to the bottom surface 20a of the platform part 20 is HD, wherein, LA/LB is more than or equal to 0.4 and less than or equal to 0.6, and HC/HD is more than or equal to 0.5 and less than or equal to 0.7, so that the adherence of the handle part 10 to the marrow cavity of the radius is good, the connection stability of the wrist joint radius prosthesis and the radius is effectively improved, and the dislocation phenomenon is reduced.

In some embodiments, the LB ranges from 10mm to 30mm in length and the HD ranges from 35mm to 60mm in length. The first boundary line 11a is a virtual line (auxiliary line) provided for convenience in describing the form of the handle 10, and the actual first boundary line 11a is not necessarily visible on the handle 10.

The outer surface of the handle part 10 between the big head end 10a and the first boundary line 11a is provided with the porous coating 11, and the shape of the handle part 10 is limited to satisfy that LA/LB is more than or equal to 0.4 and less than or equal to 0.6 and HC/HD is more than or equal to 0.5 and less than or equal to 0.7, so that the porous coating 11 on the surface of the handle part 10 can be tightly attached to the marrow cavity of the radius, and the installation stability of the handle part 10 on the radius is improved. Meanwhile, as shown in fig. 4(a), the small head end 10 of the handle 10 does not go beyond the radial isthmus after implantation, i.e., the length HD of the handle 10 does not exceed the length from the osteotomy face to the radial isthmus, thereby preventing the handle 10 from being inserted too far and damaging the radius.

The porous coating 11 may be located at any position between the large head end 10a and the first boundary line 11a, preferably, may or may not be located between the boundary between the large head end 10a and the bottom surface 20a and the first boundary line 11a, and the porous coating 11 may or may not cross the first boundary line 11a, which is not limited herein.

The porous coating 11 is provided to facilitate the radial tissue growth embedding into the porous coating 11, further enhancing the stability of the installation of the handle 10 in the radial cavity. In particular, it is preferable that the porosity of the porous coating 11 is comparable to the porosity of the radial tissue, so that as the radial tissue grows, the radial tissue can grow better into the porous coating 11, thereby achieving a stable connection with the porous coating 11, thereby improving the stability of the handle portion 10 in the medullary cavity of the radius.

The porous coating 11 can be formed by sintering metal particles or ceramic particles, has simple process, convenient manufacture, high structural strength and good wear resistance, and effectively prolongs the service life of the wrist joint and radius prosthesis.

The bottom surface 20a of the stage part 20 is provided with a porous structure layer 22, and preferably the porous structure layer 22 is connected to the porous coating layer 11. After the wrist joint radius prosthesis is installed on the radius, the bottom surface 20a of the platform part 20 is attached to the osteotomy surface of the radius, so that the radius tissue grows and is embedded into the porous structure layer 22 on the bottom surface 20a of the platform part 20, the installation stability of the wrist joint radius prosthesis on the radius is improved, and the probability of dislocation of the wrist joint is reduced.

The structure of the porous structure layer 22 may be the same as that of the porous coating layer 11, so as to improve the overall coverage effect of the wrist joint radial prosthesis, so that after the wrist joint radial prosthesis is installed on a radius, positions in contact with the radius have porous structures to facilitate radial tissue growth, and improve the overall structural stability.

Different shanks 10 as shown in table 1 were used to simulate the filling state of the shank after implantation in the medullary radial cavity.

TABLE 1 LA/LB, HC/HD parameters for different handles

	LA/LB	HC/HD
			Sample 1	0.42	0.6
Sample 2	0.58	0.53
			Sample 3	0.52	0.7
Sample 4	0.6	0.62
			Sample 5	0.4	0.5
Sample 6	0.3	0.4

The stem parts 10 of the samples 1 to 5 all meet the conditions that LA/LB is more than or equal to 0.4 and less than or equal to 0.6 and HC/HD is more than or equal to 0.5 and less than or equal to 0.7, so that after the stem parts 10 are inserted into the medullary cavity of the radius, the adherence between the porous coating 11 on the surface of the stem parts and the medullary cavity of the radius is better (see figure 4 a), the connection between the stem parts 10 and the radius is stable, the stability of the wrist joint and radius prosthesis is improved, and the phenomenon that the wrist joint is dislocated due to the instability of the wrist joint and radius prosthesis is reduced.

In the handle 10 of the sample 6, the LA/LB value is 0.3, the HC/HD value is 0.4, and the range is larger than the constraint range of the condition that LA/LB is larger than or equal to 0.4 and smaller than or equal to 0.6, and HC/HD is larger than or equal to 0.5 and smaller than or equal to 0.7. As shown in fig. 4(b), after the handle 10 is inserted into the medullary radial cavity, the porous coating 11 on the surface of the handle has poor adherence with the medullary radial cavity, and a significant gap exists between the outer surface of the handle 10 and the inner wall of the medullary radial cavity, so that the handle 10 is easy to loosen, and the wrist joint is easy to dislocate.

It should be noted that the wrist joint radius prosthesis can be used for total wrist replacement as well as for semi-wrist replacement.

For example, in the total wrist replacement, after the radial side osteotomy is completed to form a corresponding osteotomy surface, the radial medullary cavity is filed with a tool such as a radial medullary cavity file, and then the stem portion 10 is inserted into the filed radial medullary cavity, so that the platform portion 20 is kept in conformity with the osteotomy surface of the radius under fixation of the stem portion 10, thereby completing the implantation operation of the wrist joint radial prosthesis. Accordingly, the wrist bone side is implanted with the carpal bone prosthesis, and finally the joint surface of the carpal bone prosthesis is matched with the joint surface formed on the platform part 20, thereby completing the implantation of the wrist joint prosthesis.

In embodiments where the platform portion 20 is removably connected to the shank portion 10, the platform portion 20 may be a polyethylene material or a cobalt chromium molybdenum material.

Wherein, when the platform part 20 made of polyethylene material is adopted, the wrist joint radius prosthesis can be used for half wrist replacement, so that under the condition of keeping the carpal bones, the carpal bones are contacted with the joint surfaces formed on the platform part 20, and then the good wrist joint function can be realized.

In this embodiment, in the semi-wrist replacement, after the radial side osteotomy is completed to form a corresponding osteotomy surface, the radial medullary cavity is filed with a tool such as a radial medullary cavity file, and then the stem portion 10 is inserted into the filed radial medullary cavity, so that the platform portion 20 is kept in contact with the osteotomy surface of the radius under the fixation of the stem portion 10, thereby completing the implantation operation of the wrist joint radial prosthesis. The carpal bone is then placed in contact with the articular surface formed on the platform 20 to complete the semi-carpal prosthesis implantation.

In some embodiments, the small tip 10b has a diameter greater than or equal to 2mm to avoid the small tip 10b from being too sharp and scratching the inner wall of the medullary canal of the radius.

Referring again to fig. 1, a part of the platform 20 near the bottom surface 20a extends radially relative to the larger end 10a to form a flange 21 along the shank 10. referring to fig. 4a, the flange 21 is a planar sheet, and after the shank 10 is inserted into the medullary cavity of the radius, the flange 21 abuts against the osteotomy surface of the radius, thereby improving the stability of the connection between the shank 10 and the radius.

As shown in fig. 5 and 6, the top projection of the flange 21 is irregular and is close to the anatomical form to a greater extent, so as to fit the osteotomy surface of the radius in a larger area and improve the installation stability of the wrist joint and radius prosthesis.

For ease of understanding, the two points on the contour of the flange 21 that define the maximum distance are chosen to define the length of the flange 21, and the corresponding maximum vertical dimension corresponding to the length of the flange 21 defines the width of the flange 21. Referring to FIG. 5, two points of the maximum distance between any two points on the contour of the flange 21 are the first and second points, the distance between the first and second points defines the length ML of the flange 21 (i.e., the width of the flange 21 in orthographic projection), and the distance between two points on the outermost side of the contour of the flange 21 in the vertical direction defines the width AP of the flange 21 (i.e., the width of the flange 21 in lateral projection) in the vertical direction, wherein AP/ML is greater than or equal to 0.5 and less than or equal to 0.7, and ML is greater than or equal to 28mm and less than or equal to 45 mm. Such a dimensional ratio of the flange 21 is adapted to the aspect ratio of the osteotomy surface of the radius, so as to cover the osteotomy surface of the radius as much as possible while maintaining the total area of the flange 21, thereby improving the coverage of the flange 21 to the osteotomy surface of the radius (the ratio of the effective area of the flange 21 covering the osteotomy surface to the total area of the osteotomy surface), so as to enhance the stability of connection with the radius. Through the structure, the wrist joint radius prosthesis can furthest improve the installation stability with the radius while maintaining the miniaturization of the whole size.

Continuing with FIG. 5, the condition of 0.5. ltoreq. AP/ML. ltoreq.0.7, 28 mm. ltoreq. ML. ltoreq.45 mm is satisfied. The contour of the flange 21 includes a first convex arc segment 21a, a second convex arc segment 21b, a third convex arc segment 21c, a fourth convex arc segment 21e and a fifth concave arc segment 21f which are smoothly adjoined in sequence, wherein the radius of curvature R1 of the first convex arc segment 21a (corresponding to the dorsal outer edge of the radius and close to the ulna) has a value ranging from 7mm to 15mm, such as 7mm, 10mm, 12mm, 13mm or 15 mm. The radius of curvature R2 of the second convex arc segment 21b (corresponding to the dorsal radius) ranges from 15mm to 30mm, such as 15mm, 17mm, 20mm, 23mm, 26mm or 30 mm. The radius of curvature R5 of the fifth concave arc segment 21f (corresponding to the radius volar-side contour concave curve) ranges from-30 mm to-20 mm, such as-30 mm, -29.5mm, -25mm or-20 mm. The flange 21 with the structure has the outline similar to the outline of the osteotomy surface of the radius so as to cover the osteotomy surface of the radius to a greater extent and improve the connection stability of the wrist joint radius prosthesis and the radius.

It should be noted that the radius of curvature R5 of the fifth concave arc segment 21f takes a negative value, indicating that the portion of the contour of the flange 21 corresponding to the fifth concave arc segment 21f is a concave arc, and the actual radius has a value equal to the absolute value of the radius of curvature R5. For example, when the radius of curvature R5 is-25 mm, the radius of the fifth concave arc segment 21f has a value of 25mm, and the curve direction is opposite to that of the fourth convex arc segment 21 e.

In some embodiments, a straight line segment 21d is connected between the third convex arc segment 21c and the fourth convex arc segment 21e, and both the third convex arc segment 21c and the fourth convex arc segment 21e are tangent to the straight line segment 21 d. The length H of the straight line segment 21d ranges from 0mm to 10mm, preferably from 0mm to 5mm, for example, the length H of the straight line segment 21d is 1mm, 2mm, 3mm, 4mm and 5 mm. By controlling the straight line segment 21d to be a proper length, the overall shape of the flange 21 can be similar to the shape of the osteotomy surface of the radius, so that the contact area of the flange and the osteotomy surface of the radius is increased, and the installation firmness of the wrist joint radius prosthesis is improved.

It should be noted that, when the contour of the flange 21 satisfies the conditions that AP/ML is greater than or equal to 0.5 and less than or equal to 0.7 and ML is greater than or equal to 28mm and less than or equal to 45mm, the coverage of the contour of the flange 21 will be different when the first convex arc section 21a, the second convex arc section 21b and the fifth concave arc section 21f select different radii of curvature within the respective ranges, specifically, within the parameter ranges, the contour of the flange 21 and the shape of the osteotomy surface of the radius have a higher fitting degree all the time, and for a patient, the shape of the osteotomy surface of the radius is similar and only different in size, so that a plurality of flanges 21 with similar contours can be formed within the parameter ranges to be adapted to the osteotomy surfaces of radii with different sizes. For example, referring to fig. 6, the flange 21 configured according to the above parameter ranges has a contour that does not greatly change as a whole, has a high degree of similarity, and only changes in size, and the flange 21 with various specifications provided by the structure can meet the replacement requirements of radius prostheses with different osteotomy face sizes.

As shown in fig. 7, an ellipsoidal joint surface 20b is formed on a side of the platform 20 facing away from the bottom surface 20a, a short axis length of an ellipse O in a plan view projection (a projection in a direction in which an elliptical area in the projection is the largest) of the ellipsoidal joint surface 20b is W, a long axis length is L, and W/L is 0.5 or more and 0.8 or less, so that the ellipsoidal joint surface 20b is very similar to a normal radial joint surface in shape, and a wrist joint function recovery effect is good.

As shown in fig. 8, the included angle a between the major axis and the bottom surface 20a of the platform 20 is in the range of 10 ° to 25 °, for example, the included angle a is 10 °, 15 °, 20 °, or 25 °. With this configuration, the opening plane (the plane where the edge profile of the ellipse O is located) of the ellipsoidal joint surface 20b is inclined with respect to the platform 20 as a whole to be close to the ulnar deviation angle of the radius, thereby achieving a better wrist function. In the orthopedics clinic, the radius ulnar deviation angle refers to an included angle between a perpendicular line of a longitudinal axis of a radius and a connecting line of a farthest point on the radial side of a distal ulna of the radius, and particularly refers to an included angle between a distal joint surface of the radius and a perpendicular line of a longitudinal axis of the radius in a wrist joint positioning sheet.

In the orthographic projection, the included angle a1 between the undercut surface of the ellipsoidal joint surface 20b and the bottom surface 20a of the platform 20 is in the range of 10 ° to 25 °, and the undercut surface is a tangent plane parallel to the major axis of the ellipsoid where the ellipsoidal joint surface 20b is located and having the lowest tangent point. Thereby maintaining a sufficient depth of the socket joint while ensuring the entire inclination of the ellipsoidal joint surface 20 b.

As shown in fig. 9, the included angle B between the minor axis of the ellipse O and the bottom surface 20a of the platform 20 is in the range of 0 ° to 15 °, for example, the included angle B is in the range of 5 °, 7 °, 10 ° or 15 °, and in this range, the inclination angle of the ellipsoidal joint surface 20B relative to the bottom surface 20a of the platform 20 is close to the radius palm inclination angle, so as to better realize the wrist joint function. In the orthopedics clinic, the inclination angle of the palm of the radius refers to the included angle between the far-end joint surface of the radius and the perpendicular line of the longitudinal axis of the radius in the wrist joint lateral plate.

In the lateral projection, the included angle B1 between the undercut surface of the ellipsoidal joint surface 20B and the bottom surface 20a of the platform 20 is in the range of 0 ° to 15 °, for example, the included angle B is 5 °, 7 °, 10 ° or 15 °. Within this range, the ellipsoidal joint surface 20b can be entirely inclined, and a sufficient depth of the acetabular joint can be maintained.

In some embodiments, the peripheral surface of the platform portion 20 intersects the lateral projection plane at the first side line 20C and the second side line 20d, and the included angle C between the first side line 20C and the second side line 20d ranges from 5 ° to 15 °, for example, the included angle C ranges from 5 °, 8 °, 10 °, or 15 °. Through this kind of structural setting for be the horn mouth form on the platform portion 20, the one side that is close to stalk portion 10 is the ministoma side, and the one side of keeping away from stalk portion 10 is the ministoma side, makes then platform portion 20 towards the direction of keeping away from stalk portion 10, and the opening subassembly expands to the articular surface of the carpal bone side rather than the complex wrist joint of bearing better, thereby improves the stability of wrist joint function.

In some embodiments, the angle D between the first side line 20c and the normal line of the bottom surface 20a of the platform 20 ranges from 15 ° to 25 °, such as 15 °, 20 °, or 25 °.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only represent some embodiments of the present invention, and the description thereof is specific and detailed, but not to be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the spirit of the present invention, several variations and modifications can be made, which are within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims

1. The wrist joint radius prosthesis is characterized by comprising a handle part and a platform part, wherein the platform part is provided with a bottom surface, the handle part extends along a direction vertical to the bottom surface, the handle part is conical and is provided with a large head end and a small head end which are opposite, the large head end is connected with the bottom surface, a first boundary line parallel to the bottom surface is arranged between the large head end and the small head end, in orthographic projection, the width of the first boundary line is LA, the width of the junction of the large head end and the bottom surface is LB, the vertical distance from the first boundary line to the bottom surface of the platform part is HC, the vertical distance from the small head end of the handle part to the bottom surface of the platform part is HD, LA/LB is more than or equal to 0.4, and HC/HD is more than or equal to 0.5 and less than or equal to 0.7.

2. The wrist joint radius prosthesis of claim 1, wherein an outer surface of the stem between the big tip and the first boundary line is provided with a porous coating.

3. The wrist joint radius prosthesis of claim 1, wherein the tip end has a diameter greater than or equal to 2 mm.

4. The wrist joint radius prosthesis of claim 1, wherein the platform portion is formed with an ellipsoidal joint surface on a side facing away from the bottom surface, the ellipsoidal joint surface has a minor axis length W in a top view projection, and the ellipsoidal joint surface has a major axis length L in a top view projection, wherein W/L is 0.5-0.8.

5. The wrist joint radius prosthesis of claim 4, wherein the included angle A between the major axis of the top view projection of the ellipsoidal joint plane and the bottom plane ranges from 10 ° to 25 °, and/or the included angle B between the minor axis of the top view projection of the ellipsoidal joint plane and the bottom plane ranges from 0 ° to 10 °.

6. The wrist joint radius prosthesis of claim 4, wherein in orthographic projection, an included angle A1 between a lower tangent plane of the ellipsoidal joint surface and the bottom surface ranges from 10 ° to 25 °, and/or in lateral projection, an included angle B1 between a lower tangent plane of the ellipsoidal joint surface and the bottom surface ranges from 0 ° to 10 °.

7. The wrist joint radius prosthesis of claim 1, wherein the circumferential surface of the platform portion intersects the lateral projection plane at a first side line and a second side line, and an included angle C between the first side line and the second side line ranges from 5 ° to 15 °.

8. The wrist joint radius prosthesis of claim 7, wherein an angle D between the first side line and a normal to the bottom surface ranges from 15 ° to 25 °.

9. The wrist joint radius prosthesis of claim 1, wherein the portion of the platform portion adjacent to the bottom surface extends radially relative to the big head end along the stem portion to form a flange, the two points of the largest distance between any two points on the contour of the flange are a first point and a second point, the distance between the first point and the second point defines a length ML of the flange, and the distance between the two points on the outermost side of the contour of the flange in the vertical direction defines a width AP of the flange, wherein the distance between the two points on the outermost side of the contour of the flange in the vertical direction is 0.5-0.7, and the distance between the two points on the outermost side of the contour of the flange is 28 mm-45 mm.

10. The wrist joint radius prosthesis of claim 9, wherein the contour of the flange comprises a first convex arc segment, a second convex arc segment, a third convex arc segment, a fourth convex arc segment and a fifth concave arc segment which are smoothly adjoined in sequence, wherein the radius of curvature R1 of the first convex arc segment ranges from 7mm to 15mm, the radius of curvature R2 of the second convex arc segment ranges from 15mm to 30mm, and the radius of curvature R5 of the fifth concave arc segment ranges from-30 mm to-20 mm.

11. The wrist joint radius prosthesis of claim 10, wherein a straight segment is connected between the third convex arc segment and the fourth convex arc segment, and the third convex arc segment and the fourth convex arc segment are both tangent to the straight segment.

12. The wrist joint radius prosthesis of claim 2, wherein the bottom surface of the platform portion is provided with a porous structural layer, the porous structural layer being connected to the porous coating layer.