WO2022127330A1 - Wrist joint radial prosthesis - Google Patents

Abstract

The wrist joint radial prosthesis provided in the present application comprises a handle part and a platform part. The platform part has a bottom surface. The handle part extends in a direction perpendicular to the bottom surface. The handle part is conical and has a large end and a small end which are opposite to each other. The large end is connected to the bottom surface. A first boundary line parallel to the bottom surface is provided between the large end and the small end. In a frontal projection, the width of the first boundary line is LA, the width of a junction of the large end and the bottom surface is LB, a vertical distance from the first boundary line to the bottom surface of the platform part is HC, a vertical distance from the small end of the handle part to the bottom surface of the platform part is HD, wherein 0.4≤LA/LB≤0.6 and 0.5≤HC/HD≤0.7.

Description

wrist radial prosthesis

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority of the Chinese patent application with application number 2020114852430 filed with the China Patent Office on December 16, 2020, the entire contents of which are incorporated herein by reference.

technical field

The present application relates to the technical field of medical devices, and in particular, to a wrist radial prosthesis.

Background technique

The wrist joint is one of the most flexible and important joints in the human body. For the treatment of traumatic, degenerative wrist arthritis, rheumatoid wrist arthritis and other severely damaged diseases, most of the wrist joint fusions were used before. With the development of medicine and technology and the urgent desire of patients to relieve pain while preserving the mobility of their wrist joints, total wrist arthroplasty is more and more used in the treatment of wrist joints.

However, the current wrist radial prosthesis has poor installation stability and is prone to dislocation.

SUMMARY OF THE INVENTION

According to various embodiments of the present application, a wrist joint radial prosthesis is provided, which effectively solves the technical problems of poor stability and easy dislocation.

The present application provides a radial prosthesis for a wrist joint, comprising: a handle part, which is tapered and has opposite big head ends and small head ends; and a platform part, the platform part has a bottom surface. The handle portion extends in a direction perpendicular to the bottom surface. The big end is connected with the bottom surface. A first boundary line parallel to the bottom surface is set between the large end and the small end. In the orthographic projection, the width of the first boundary line is LA, the width of the junction between the large end and the bottom surface is LB, and the vertical distance from the first boundary line to the bottom surface of the platform portion is HC , the maximum vertical distance from the small end to the bottom surface is HD, where 0.4≤LA/LB≤0.6 and 0.5≤HC/HD≤0.7 are satisfied.

In one of the embodiments, the outer surface of the portion of the handle portion between the large end and the first boundary line is provided with a porous coating.

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

In one of the embodiments, a side of the platform portion facing away from the bottom surface is formed with an ellipsoidal joint surface. The short-axis length of the plan projection of the ellipsoid articular surface is W, and the long-axis length of the plan projection of the ellipsoid articular surface is L, and 0.5≤W/L≤0.8 is satisfied.

In one embodiment, the angle A between the long axis of the top-view projection of the ellipsoid articular surface and the bottom surface ranges from 10° to 25°, and/or the top-view projection of the ellipsoid articular surface The value range of the included angle B between the short axis of and the bottom surface is 0° to 10°.

In one embodiment, in the frontal projection, the angle A1 between the lower section of the ellipsoid articular surface and the bottom surface ranges from 10° to 25°, and/or in the lateral projection, the The value range of the included angle B1 between the lower section of the ellipsoid joint surface and the bottom surface is 0°˜10°.

In one embodiment, the peripheral surface of the platform portion and the lateral projection surface intersect the first edge line and the second edge line. The value range of the included angle C between the first edge line and the second edge line is 5°˜15°.

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

In one of the embodiments, a portion of the platform portion that is close to the bottom surface extends to form a flange relative to the large end in the radial direction of the handle portion. Among any two points on the contour of the flange, the two points with the largest distance are the first point and the second point. The distance between the first take point and the second take point defines the length ML of the flange. In the vertical direction of the line connecting the first and second points, the distance between the two outermost points on the outline of the flange in the vertical direction defines the width AP of the flange , where 0.5≤AP/ML≤0.7 and 28mm≤ML≤45mm are satisfied.

In one embodiment, the contour of the flange includes 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 that are smoothly adjacent in sequence. Wherein, the value range of the curvature radius R1 of the first convex arc segment is 7mm～15mm, the value range of the curvature radius R2 of the second convex arc segment is 15mm～30mm, and the fifth concave arc segment has a value range of 15mm～30mm. The value range of the radius of curvature R5 is -30mm to -20mm.

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

In one of the embodiments, the bottom surface of the platform portion is provided with a porous structure layer.

In one embodiment, the porous structure layer is connected to the porous coating.

In one of the embodiments, the platform portion and the handle portion are detachably connected.

In one embodiment, the platform portion and the handle portion are integrally formed.

The wrist radial prosthesis provided by the present application includes a handle portion and a platform portion. The handle portion extends in a direction perpendicular to the bottom surface, wherein the handle portion is tapered and has opposite large head ends and small head ends, and the large head end is connected to the bottom surface. , there is a first boundary line parallel to the bottom surface between the big end and the small end. In the orthographic projection, the width of the first boundary line is LA, the width of the junction between the big end and the bottom surface is LB, and the first boundary line The vertical distance to the bottom of the platform is HC, and the vertical distance from the small end of the handle to the bottom of the platform is HD, where 0.4≤LA/LB≤0.6, 0.5≤HC/HD≤0.7, so that the handle It has good adherence to the radial medullary cavity, which can effectively improve the connection stability of the wrist radial prosthesis and the radius, and reduce the occurrence of dislocation.

Description of drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the accompanying drawings that are used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only These are some embodiments of the present application. For those of ordinary skill in the art, the drawings of other embodiments can also be obtained according to these drawings without creative efforts.

1 is a schematic structural diagram of a wrist radial prosthesis according to an embodiment;

2 is a schematic structural diagram of a wrist radial prosthesis according to another embodiment;

3 is a schematic structural diagram of a wrist radial prosthesis according to another embodiment;

Fig. 4(a) is a schematic diagram of the state of the wrist radial prosthesis implanted into the radius according to one embodiment;

Figure 4(b) is a schematic diagram of the state of the wrist radial prosthesis of another embodiment when implanted into the radius;

5 is a schematic view of an embodiment of the wrist radial prosthesis after implantation of the radius from the direction of the osteotomy surface;

Fig. 6 is a schematic view from the direction of the osteotomy surface after various sizes of wrist radial prostheses are implanted into the radius, wherein the peripheral contours of the flanges of the wrist radial prostheses of various sizes are schematically shown on the same radius osteotomy surface;

7 is a schematic diagram of an edge profile of an ellipsoid articular surface of a wrist radial prosthesis according to an embodiment;

8 is a schematic diagram of the structure and morphology of a wrist radial prosthesis in an orthotopic wrist film according to an embodiment;

FIG. 9 is a schematic diagram of the structure of the radial prosthesis of the wrist joint in the lateral view of the wrist joint according to an embodiment.

Detailed ways

In order to make the above objects, features and advantages of the present application more clearly understood, the 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. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

In the description of this 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 other indicated orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the application and simplifying the description, rather than indicating or implying the indicated device or Elements must have a particular orientation, be constructed and operate in a particular orientation and are therefore not to be construed as limitations on this application.

In addition, the terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature delimited with "first", "second" may expressly or implicitly include at least one of that feature. In the description of the present application, "plurality" means at least two, such as two, three, etc., unless expressly and specifically defined otherwise.

In this application, unless otherwise expressly specified and limited, the terms "installed", "connected", "connected", "fixed" and other terms should be understood in a broad sense, for example, it may be a fixed connection or a detachable connection , or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between the two elements, unless otherwise specified limit. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific situations.

In this application, unless otherwise expressly stated and defined, a first feature "on" or "under" a second feature may be in direct contact with the first and second features, or the first and second features indirectly through an intermediary touch. Also, the first feature being "above", "over" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is level higher than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature has a lower level than the second feature.

It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or an intervening element 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 similar expressions used herein are for the purpose of illustration only and do not represent the only embodiment.

Referring to FIG. 1 , a wrist joint radial prosthesis provided by the present application includes a handle portion 10 and a platform portion 20 .

In one embodiment, the platform part 20 is detachably connected with the handle part 10 , so that the handle part 10 and the platform part 20 can flexibly cooperate with different models of the platform part 20 and the handle part 10 respectively. The two can be detachably connected by snap fit, which is convenient for disassembly and assembly, and is beneficial to improve the matching efficiency between the platform portion 20 and the handle portion 10 . For example, the handle portion 10 is provided with a sliding protrusion, and the platform portion 20 is provided with a sliding groove slidably matched with the sliding protrusion. The platform portion 20 is limited to the handle portion 10 in the direction perpendicular to the bottom surface 20a of the platform portion 20 (ie, the extending direction of the normal line of the bottom surface 20a ) by the cooperation between the sliding protrusion and the sliding groove. In this structure, after the sliding protrusion and the sliding groove are slidably matched, the platform portion 20 can be quickly assembled to the handle portion 10 by pushing the platform portion 20 relative to the handle portion 10 in a direction parallel to the bottom surface 20a. Correspondingly, when it needs to be removed from the handle portion 10, it is only necessary to push the platform portion 20 away from the handle portion 10 along the sliding protrusion.

In one embodiment, as shown in FIG. 2 , the platform portion 20 and the handle portion 10 are integrally formed. This integrated structure reduces the number of components, thereby facilitating implantation into the radius, and has better stability. When the platform portion 20 and the handle portion 10 are integrally formed, there is a large space for process selection. The wrist radial prosthesis can be obtained by cutting and grinding the material, or it can be processed by 3D printing.

In some embodiments, the material of the wrist radial prosthesis can be made of 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 radial prosthesis can be made of titanium alloy material, so as to facilitate processing by 3D printing.

Figure 3 shows a frontal projection of a wrist radial prosthesis. The so-called upright position, for the human wrist, is the front of the wrist, that is, the position looking down on the palm when the palm is placed flat on the table; for the radial prosthesis, it is the position with the largest projected area, that is, parallel to the bottom surface 20a and The orientation where the width of the prosthesis is widest is observed. The orientation perpendicular to the orthotopic in the direction parallel to the bottom surface 20a is the lateral orientation, that is, the orientation of the surface where the width of the prosthesis is the narrowest.

The shank 10 is tapered (ie, in an orthographic projection, gradually widening or narrowing from one end to the other), with opposing large and small ends 10a and 10b. The platform portion 20 has a bottom surface 20a, and the bottom surface 20a is substantially perpendicular to the handle portion 10 and is connected to the large end 10a. There is a first boundary line 11a between the large end 10a and the small end 10b, and 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 between the large end 10a of the handle portion 10 and the bottom surface 20a is LB, and the vertical distance from the first boundary line 11a to the bottom surface 20a of the platform portion 20 is HC , the vertical distance from the end point of the small end 10b of the handle portion 10 to the bottom surface 20a of the platform portion 20 is HD, where 0.4≤LA/LB≤0.6 and 0.5≤HC/HD≤0.7 are satisfied, the handle 10 and The radial medullary cavity has good adherence, which can effectively improve the connection stability of the wrist radial prosthesis and the radius to reduce the occurrence of dislocation.

In some embodiments, the length of the LB is in the range of 10mm-30mm and the length of the HD is in the range of 35mm-60mm. It should be noted that the first boundary line 11a is a virtual line (auxiliary line) provided for the convenience of describing the shape of the handle portion 10 , and the real first boundary line 11a may not necessarily be visible on the handle portion 10 .

The outer surface of the portion of the shank 10 between the large end 10a and the first boundary line 11a is provided with a porous coating 11 . By defining the shape of the handle 10 to satisfy 0.4≤LA/LB≤0.6 and 0.5≤HC/HD≤0.7, the porous coating 11 on the surface of the handle 10 can be closely attached to the radial medullary cavity, thereby improving the position of the handle 10 in the radial bone. installation stability. At the same time, as shown in FIG. 4(a), the small head end 10 of the stem 10 will not cross the radial isthmus after implantation, that is, the length HD of the stem 10 does not exceed the osteotomy surface of the radius (the bottom surface 20a will fit on the radial isthmus). Osteotomy surface) to the length of the radial isthmus, to prevent the stem 10 from being inserted too deep to damage the radius.

The porous coating 11 can be located anywhere between the big end 10a and the first boundary line 11a, for example, it can be covered between the junction of the big head 10a and the bottom surface 20a and the first boundary line 11a, or not. The porous coating 11 may or may not cross the first boundary line 11a, which is not limited here.

The porous coating 11 is provided to facilitate the growth of the radial bone tissue into the porous coating 11, which further enhances the installation stability of the handle 10 in the radial medullary cavity. Specifically, in one of the embodiments, the porosity of the porous coating 11 is comparable to the porosity of the radial bone tissue, so that with the growth of the radial bone tissue, the radial bone tissue can better grow into the porous coating 11, so as to achieve the same The stable connection of the porous coating 11 improves the stability of the handle 10 in the radial medullary cavity.

The porous coating 11 can be formed by sintering metal particles or ceramic particles, and the process is simple, easy to manufacture, and has high structural strength and good wear resistance, which effectively improves the service life of the wrist radial prosthesis.

The bottom surface 20 a of the platform portion 20 is provided with a porous structure layer 22 . In one of the embodiments, the porous structure layer 22 is connected to the porous coating layer 11 . After the wrist radial prosthesis is installed on the radius, the bottom surface 20a of the platform portion 20 is in contact with the osteotomy surface of the radius, so that the radial bone tissue grows and embeds the porous structure layer 22 on the bottom surface 20a of the platform portion 20, so as to improve the radial bone of the wrist joint. The installation stability of the prosthesis on the radius reduces the chance of dislocation at the wrist joint.

The structure of the porous structure layer 22 can be the same as the structure of the porous coating 11, so as to improve the overall covering effect of the radial prosthesis of the wrist joint, so that after the radial prosthesis of the wrist joint is installed on the radius, the positions in contact with the radius are porous. The structure facilitates the growth of radial tissue into the wrist radial prosthesis and improves the overall structural stability. In other embodiments, the structure of the porous structure layer 22 may also adopt a structure or material different from that of the porous coating layer 11 , which is not limited herein.

The filling state of different stems 10 after being implanted into the radial medullary cavity was simulated by software, and the results are shown in Table 1.

Table 1 LA/LB, HC/HD parameters of different shanks

	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 stems 10 of samples 1 to 5 all meet the conditions of 0.4≤LA/LB≤0.6, 0.5≤HC/HD≤0.7, so that after the stem 10 is inserted into the radial medullary cavity, the porous coating 11 on its surface is in contact with the radial cavity. The bone marrow cavity has better adherence (see Figure 4a), so that the connection between the handle 10 and the radius is stable, which improves the stability of the wrist radial prosthesis and reduces the instability of the wrist joint radial prosthesis. Dislocation of the joint occurs.

For the handle 10 of the sample 6, the LA/LB value is 0.3, and the HC/HD value is 0.4, which is beyond the range constrained by the conditions of 0.4≤LA/LB≤0.6 and 0.5≤HC/HD≤0.7. As shown in Figure 4(b), after the handle 10 is inserted into the radial medullary cavity, the porous coating 11 on its surface has poor adherence to the radial medullary cavity, and there is a clear gap between the outer surface of the handle 10 and the inner wall of the radial medullary cavity. Therefore, the handle 10 is prone to loosening, which may easily lead to dislocation at the wrist joint.

It should be noted that the wrist radial prosthesis can be used for total wrist replacement or half wrist replacement.

For example, in total wrist replacement, after the radial side osteotomy is completed to form the corresponding osteotomy surface, the radial medullary canal is ripped with a tool such as a radial medullary canal rasp, and then the handle 10 is inserted into the reamed radial medullary medullary canal, so that the Under the fixation of the handle portion 10, the platform portion 20 remains in contact with the osteotomy surface of the radius, thereby completing the implantation operation of the radial prosthesis of the wrist joint. Correspondingly, the operation of implanting the carpal prosthesis is performed on the carpal side, and finally the articular surface of the carpal prosthesis is matched with the articular surface formed on the platform portion 20, and the implantation of the wrist prosthesis is completed.

In the embodiment in which the platform portion 20 is detachably connected to the handle portion 10, the platform portion 20 may be a polyethylene material or a cobalt chromium molybdenum material.

Among them, when the platform part 20 made of polyethylene material is used, the wrist radial prosthesis can be used for hemi-carpal replacement, so that a good wrist can be achieved by contacting the carpal bone with the articular surface formed on the platform part 20 under the condition of retaining the carpal bone. joint function.

In this embodiment, in the hemicarpal arthroplasty, after the radial side osteotomy is completed to form the corresponding osteotomy surface, the radial medullary canal is ripped with a tool such as a radial medullary canal file, and then the handle 10 is inserted into the reamed radial medullary canal Therefore, under the fixation of the handle portion 10, the platform portion 20 remains in contact with the osteotomy surface of the radius, thereby completing the implantation operation of the radial prosthesis of the wrist joint. Then, the carpal bone is brought into contact with the articular surface formed on the platform portion 20 to complete the implantation of the hemi-carpal joint prosthesis.

In some embodiments, the diameter of the small tip 10b is greater than or equal to 2 mm, which can prevent the small tip 10b from being too sharp to scratch the inner wall of the radial medullary cavity.

Referring again to FIG. 1 , a portion of the platform portion 20 close to the bottom surface 20 a extends along the radial direction of the handle portion 10 to form a flange 21 relative to the big end 10 a. 4a, the flange 21 is in the shape of a flat sheet. After the handle 10 is inserted into the radial medullary cavity, the flange 21 abuts on the osteotomy surface of the radius, thereby improving the connection stability between the handle 10 and the radius.

As shown in FIGS. 5 and 6 , the top projection of the flange 21 can be in an irregular shape, so as to be closer to the anatomical shape to a greater extent, so that the flange 21 fits with the osteotomy surface of the radius in a larger area and improves the wrist joint. Installation stability of radial prosthesis.

For ease of understanding, two points on the contour of the flange 21 that form the largest distance are selected to define the length of the flange 21 , and the corresponding maximum vertical dimension corresponding to the length of the flange 21 is selected to define the width of the flange 21 . 5, in any two points on the outline of the flange 21, the two points with the maximum distance are the first point and the second point, and the distance between the first point and the second point defines the flange. Length ML of 21 (ie width of flange 21 in orthographic projection). In the vertical direction of the line connecting the first and second points, the distance between the two outermost points on the outline of the flange 21 in the vertical direction defines the width AP of the flange 21 (that is, the lateral projection width of the middle flange 21 ), wherein 0.5≤AP/ML≤0.7, 28mm≤ML≤45mm is satisfied. The size ratio of the flange 21 is adapted to the aspect ratio of the osteotomy surface of the radius, so that the flange 21 can cover the osteotomy of the radius as much as possible while maintaining the total area of the flange 21 unchanged. Therefore, the coverage ratio 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) is increased, so as to enhance the connection stability with the radius. Through this structural arrangement, the wrist radial prosthesis can maximize the installation stability with the radius while maintaining the overall size miniaturization.

Continuing to refer to FIG. 5 , under the conditions of 0.5≤AP/ML≤0.7, 28mm≤ML≤45mm, the outline of the flange 21 includes the first convex arc segment 21a and the second convex arc segment 21b which are smoothly adjacent to each other in sequence , a third convex arc segment 21c, a fourth convex arc segment 21e and a fifth concave arc segment 21f. The radius of curvature R1 of the first convex arc segment 21a (corresponding to the dorsal lateral edge of the radius and close to the ulna) ranges from 7mm to 15mm, such as 7mm, 10mm, 12mm, 13mm or 15mm. The radius of curvature R2 of the second convex arc segment 21b (corresponding to the dorsal edge of the radius) ranges from 15mm to 30mm, such as 15mm, 17mm, 20mm, 23mm, 26mm or 30mm. The value range of the curvature radius R5 of the fifth concave arc segment 21f (corresponding to the concave curve of the volar radial contour) is -30mm to -20mm, for example, -30mm, -29.5mm, -25mm or -20mm. The contour of the flange 21 of this structure is similar to the contour of the osteotomy surface of the radius, so that it can cover the osteotomy surface of the radius to a greater extent and improve the connection stability between the radial prosthesis of the wrist and the radius.

It should be pointed out that the curvature radius R5 of the fifth concave arc segment 21f takes a negative value, indicating that the part of the contour of the flange 21 corresponding to the fifth concave arc segment 21f is a concave arc, and the actual value of its radius is the curvature radius The absolute value of R5. For example, when the radius of curvature R5 is -25mm, the value of the radius of the fifth concave arc segment 21f is 25mm, and its bending direction is opposite to that of the fourth convex arc segment 21e.

In some embodiments, a straight line segment 21d is connected between the third convex arc segment 21c and the fourth convex arc segment 21e. Both the third convex arc segment 21c and the fourth convex arc segment 21e are tangent to the straight line segment 21d. The value range of the length H of the straight section 21d is 0mm-10mm, preferably 0mm˜5mm, for example, the length H of the straight section 21d is 1mm, 2mm, 3mm, 4mm and 5mm. By controlling the straight segment 21d to an appropriate length, the overall shape of the flange 21 can be similar to the shape of the osteotomy surface of the radius, so as to increase the contact area between the flange 21 and the osteotomy surface of the radius, thereby improving the radius of the wrist joint The installation firmness of the prosthesis.

It should be noted that, under the condition that the profile of the above-mentioned flange 21 satisfies the conditions of 0.5≤AP/ML≤0.7 and 28mm≤ML≤45mm, the first convex arc segment 21a, the second convex arc segment 21b and the fifth concave arc When the segments 21f are selected with different curvature radii within their respective ranges, the coverage of the contour of the flange 21 will be different. To be precise, under the above parameter range, the contour of the flange 21 always has a high degree of fit with the shape of the osteotomy surface of the radius, and for the patient, the shape of the osteotomy surface of the radius is similar, only the size Therefore, within the range of the above parameters, a plurality of flanges 21 with similar contours can be formed to adapt to the osteotomy surfaces of different sizes of the radius. For example, as shown in FIG. 6 , the outline of the flange 21 configured according to the above parameter range will not change greatly on the whole, the similarity is very high, and only the size changes. Various specifications under this structure are set. The flange 21 can meet the replacement needs of radial prostheses with different osteotomy surfaces.

As shown in FIG. 7 , an ellipsoidal joint surface 20b is formed on the side of the platform portion 20 that is away from the bottom surface 20a. The short-axis length of the ellipse O of the top-view projection of the ellipsoid joint surface 20b (the projection of the direction with the largest ellipse area in the projection) is W, and the long-axis length is L, and satisfies 0.5≤W/L≤0.8, so that The shape of the ellipsoid articular surface 20b is close to that of the normal radial articular surface, so that after the replacement of the radial prosthesis, the wrist joint function can be recovered well.

8 , the angle A between the long axis and the bottom surface 20a of the platform portion 20 ranges from 10° to 25°, for example, the angle A is 10°, 15°, 20° or 25°. Under this structural arrangement, the opening plane of the ellipsoid articular surface 20b (the plane where the edge contour of the ellipse O is located) will be inclined relative to the platform portion 20 as a whole, so as to be close to the radial and ulnar declination, so as to better realize the wrist joint. Function. Among them, in orthopaedic clinics, the radius-ulnar declination refers to the angle between the vertical line of the longitudinal axis of the radius and the line connecting the farthest point on the distal ulnar side of the radius, specifically in the wrist anteroposterior radiograph , the angle between the distal articular surface of the radius and the perpendicular to the longitudinal axis of the radius.

In the orthographic projection, the value range of the angle A1 between the lower section of the ellipsoid joint surface 20b and the bottom surface 20a of the platform portion 20 is 10°˜25°. The lower cut plane refers to a cut plane that is parallel to the long axis of the ellipsoid where the ellipsoid joint surface 20b is located and has the lowest tangent point. This ensures that the ellipsoid articular surface 20b is inclined as a whole while maintaining a sufficient depth of the acetabular joint.

9, the value range of the included angle B between the short axis of the ellipse O and the bottom surface 20a of the platform portion 20 is 0°～15°, for example, the included angle B is 5°, 7°, 10° or 15°. Within this angle range, the inclination of the ellipsoid articular surface 20b relative to the bottom surface 20a of the platform portion 20 is close to the inclination of the radial palm, so that the wrist joint function can be better achieved. Among them, in the orthopedic clinic, the radial palmar inclination angle refers to the angle between the distal articular surface of the radius and the vertical line of the longitudinal axis of the radius in the lateral radiograph of the wrist joint.

In the lateral projection, the angle B1 between the lower section of the ellipsoid joint surface 20b and the bottom surface 20a of the platform portion 20 ranges from 0° to 15°, for example, the angle B is 5°, 7°, 10° ° or 15°. Within this value range, the ellipsoid articular surface 20b can be tilted as a whole while maintaining a sufficient depth of the acetabular joint.

In some embodiments, the peripheral surface of the platform portion 20 and the lateral projection surface intersect the first edge line 20c and the second edge line 20d. The value range of the included angle C between the first side line 20c and the second side line 20d is 5°˜15°, for example, the value of the included angle C is 5°, 8°, 10° or 15°. Through this structural arrangement, the platform portion 20 has a bell mouth shape, the side of the platform portion 20 close to the handle portion 10 is the small mouth side, and the side away from the handle portion 10 is the large mouth side. In the direction of the handle portion 10, the opening gradually expands, so as to better support the articular surface of the carpal bone side of the wrist joint to be matched with it, thereby improving the stability of the function of the wrist joint.

In some embodiments, the value range of the included angle D between the first edge line 20c and the normal line of the bottom surface 20a of the platform portion 20 is 15°˜25°, for example, the value of the included angle D may be 15°, 20° ° or 25°.

The wrist joint radial prosthesis according to various embodiments of the present application can effectively solve the technical problems of poor stability and easy dislocation.

The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity, all possible combinations of the technical features in the above-described embodiments are not described. However, as long as there is no contradiction between the combinations of these technical features, All should be regarded as the scope described in this specification.

The above-mentioned embodiments only represent several embodiments of the present application, and the descriptions thereof are relatively specific and detailed, but should not be construed as a limitation on the scope of the patent application. It should be pointed out that for those skilled in the art, without departing from the concept of the present application, several modifications and improvements can be made, which all belong to the protection scope of the present application. Therefore, the scope of protection of the patent of the present application shall be subject to the appended claims.

Claims (15)

1. A wrist radial prosthesis, comprising:

   a shank; it is tapered and has opposing large and small ends; and

   a platform portion, which has a bottom surface,

   The handle portion extends in a direction perpendicular to the bottom surface, the large end is connected to the bottom surface, and a first edge parallel to the bottom surface is arranged between the large end and the small end. The boundary line, in the orthographic projection, the width of the first boundary line is LA, the width of the junction between the large end and the bottom surface is LB, and the vertical distance from the first boundary line to the bottom surface of the platform portion is HC, and the maximum vertical distance from the small end to the bottom surface is HD, where 0.4≤LA/LB≤0.6 and 0.5≤HC/HD≤0.7 are satisfied.
2. The radial prosthesis of the wrist joint according to claim 1, wherein a porous coating is provided on the outer surface of the portion of the handle between the large head end and the first boundary line.
3. The radial prosthesis of the wrist joint according to claim 1, wherein the diameter of the small head end is greater than or equal to 2 mm.
4. The wrist radial prosthesis according to claim 1, wherein an ellipsoid articular surface is formed on a side of the platform portion facing away from the bottom surface, and a short axis length of a plan projection of the ellipsoid articular surface is is W, and the length of the long axis of the top-view projection of the ellipsoid articular surface is L, and satisfies 0.5≤W/L≤0.8.
5. The radial prosthesis for wrist joint according to claim 4, wherein the angle A between the long axis of the top-view projection of the ellipsoid articular surface and the bottom surface ranges from 10° to 25°, and/ Or the value range of the included angle B between the short axis of the top-view projection of the ellipsoid joint surface and the bottom surface is 0° to 10°.
6. The wrist radial prosthesis according to claim 4, wherein, in the frontal projection, the angle A1 between the lower section of the ellipsoid articular surface and the bottom surface ranges from 10° to 25°, And/or in the lateral projection, the value range of the included angle B1 between the lower section of the ellipsoid articular surface and the bottom surface is 0° to 10°.
7. The radial prosthesis for wrist joint according to claim 1, wherein the peripheral surface of the platform portion and the lateral projection surface intersect with a first edge line and a second edge line, and the first edge line and the first edge line The value range of the included angle C between the two sides is 5° to 15°.
8. The radial prosthesis for wrist joint according to claim 7, wherein the included angle D between the first edge line and the normal line of the bottom surface ranges from 15° to 25°.
9. The radial prosthesis for wrist joint according to claim 1, wherein a portion of the platform portion close to the bottom surface forms a flange extending in the radial direction of the stem portion relative to the big head end, and a flange is formed on the convex portion. In any two points on the outline of the edge, the two points with the largest distance are the first and second points, and the distance between the first and second points defines the length ML of the flange, In the vertical direction to the line connecting the first and second points, the distance in the vertical direction between the two outermost points on the outline of the flange defines the width of the flange AP, wherein, 0.5≤AP/ML≤0.7, and 28mm≤ML≤45mm.
10. The radial prosthesis for wrist joint according to claim 9, wherein the outline of the flange comprises a first convex arc segment, a second convex arc segment, a third convex arc segment, and a fourth convex arc segment that are smoothly adjacent to each other in sequence segment and the fifth concave arc segment, wherein the value range of the curvature radius R1 of the first convex arc segment is 7mm～15mm, and the value range of the curvature radius R2 of the second convex arc segment is 15mm～30mm, The value range of the curvature radius R5 of the fifth concave arc segment is -30mm～-20mm.
11. The radial prosthesis for wrist joint according to claim 10, wherein a straight line 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 connected with a straight line segment. The four convex arc segments are all tangent to the straight line segment.
12. The radial prosthesis for wrist joint according to claim 2, wherein the bottom surface of the platform portion is provided with a porous structure layer.
13. The radial wrist prosthesis of claim 12, wherein the porous structure layer is connected to the porous coating.
14. The wrist radial prosthesis according to claim 1, wherein the platform portion and the handle portion are detachably connected.
15. The wrist radial prosthesis according to claim 1, wherein the platform portion and the handle portion are integrally formed.

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