Knee prosthesis

Abstract

The present invention provides a knee joint prosthesis, comprising: a tibial plateau, the upper surface of which is provided with a first arc-shaped groove; a shim platform, the shim platform is rotatably mounted on the tibial plateau, the lower surface of which is provided with a second arc-shaped groove corresponding to the first arc-shaped groove; and a ball, which is mounted in the first arc-shaped groove and the second arc-shaped groove, and the tibial plateau supports the shim platform through the ball. The technical solution of the present application effectively solves the problem of poor flexibility of knee joint prostheses in the related art.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and in particular to a knee joint prosthesis. Background Art

[0002] The knee joint is the main joint of the lower limbs. Its structure and function are the most complex among all joints in the human body. At the same time, the knee joint is also one of the joints that is most susceptible to damage. Knee replacement surgery is an effective means to treat severe knee lesions and deformities. Successful knee replacement surgery can significantly relieve patients' knee pain and improve knee function over a long period of time, ensuring the stability of lower limb standing and the joint activity required for daily life.

[0003] In the related art, after the knee joint prosthesis is implanted in the human body, a torque is generated between the gasket platform and the tibial platform during the movement of the knee joint, and micro-motion occurs at the interface, causing wear of the gasket platform, debris, and complications such as bone dissolution and prosthesis sinking. In addition, after the knee joint prosthesis is implanted in the patient's body, the gasket platform and the femoral condyle prosthesis restrict relative rotational movement, which easily leads to poor flexibility of the prosthesis. Summary of the invention

[0004] The main purpose of the present invention is to provide a knee joint prosthesis to solve the problem of poor flexibility of the knee joint prosthesis in the related art.

[0005] In order to achieve the above-mentioned purpose, the present invention provides a knee joint prosthesis, including: a tibial plateau, the upper surface of which is provided with a first arc-shaped groove; a shim platform, the shim platform is rotatably mounted on the tibial plateau, and the lower surface of the shim platform is provided with a second arc-shaped groove corresponding to the first arc-shaped groove; and balls are installed in the first arc-shaped groove and the second arc-shaped groove, and the tibial plateau supports the shim platform through the balls.

[0006] Furthermore, the gasket platform includes a gasket body and a connecting platform, the connecting platform is located below the gasket body, the connecting platform is connected to the bottom of the gasket platform, and the second arc groove is arranged on the lower surface of the connecting platform.

[0007] Furthermore, there are multiple balls, and the multiple balls are installed in the first arc groove and the second arc groove. The sum of the diameters of the multiple balls is smaller than the length of the first arc groove, and the sum of the diameters of the multiple balls is smaller than the length of the second arc groove.

[0008] Furthermore, there are a plurality of first arcuate grooves and a plurality of second arcuate grooves, the plurality of first arcuate grooves are symmetrical with respect to the center of the tibial plateau, and the second arcuate grooves are symmetrical with respect to the center of the connecting platform.

[0009] Furthermore, a first positioning device is arranged between the gasket body and the connecting platform, and the first positioning device includes a first positioning hole and a first positioning column. One of the first positioning hole and the first positioning column is arranged on the gasket body, and the other is arranged on the connecting platform. The first positioning column and the first positioning hole are plugged in and transitionally matched.

[0010] Furthermore, a second positioning device is arranged between the tibial platform and the gasket platform, and the second positioning device is located at the center of the tibial platform and the gasket platform. The second positioning device includes a second positioning hole and a second positioning column. One of the second positioning column and the second positioning hole is arranged on the tibial platform, and the other is arranged on the gasket platform. The second positioning column and the second positioning hole are plugged in and transitionally matched.

[0011] Furthermore, a first mounting hole is arranged at the center position of the gasket body, a cylindrical portion is arranged on the connecting platform, a second mounting hole is arranged in the cylindrical portion, the cylindrical portion is inserted into the first mounting hole, and the second mounting hole forms a second positioning hole.

[0012] Furthermore, the surface roughness of the upper surface of the tibial plateau, the lower surface of the connecting platform, the outer surface of the second positioning column and the inner surface of the second positioning hole are all less than or equal to Ra0.16.

[0013] Furthermore, a positioning structure is provided on the lower surface of the tibial plateau.

[0014] Furthermore, the tibial platform, the connecting platform and the ball are made of metal or ceramic.

[0015] By applying the technical solution of the present invention, the shim platform is installed on the tibial platform, the upper surface of the tibial platform is provided with a first arc groove, and the lower surface of the shim platform is provided with a second arc groove, and the first arc groove and the second arc groove are provided correspondingly. The ball is installed in the first arc groove and the second arc groove. The ball can reduce the friction between the tibial platform and the shim platform, and at the same time, the ball can limit the rotation angle of the shim platform relative to the tibial platform while sliding in the first arc groove and the second arc groove. Therefore, the technical solution of the present application effectively solves the problem of poor flexibility of knee joint prosthesis in the related art. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0017] Figure 1 A schematic diagram of the exploded structure of an embodiment of a knee joint prosthesis according to the present invention is shown;

[0018] Figure 2 Shows Figure 1Schematic cross-sectional view of a knee prosthesis;

[0019] Figure 3 Shows Figure 1 A schematic diagram of the three-dimensional structure of a connection platform of a knee joint prosthesis;

[0020] Figure 4 Shows Figure 3 A bottom-up schematic diagram of a connection platform;

[0021] Figure 5 Shows Figure 3 A schematic front view of a connection platform;

[0022] Figure 6 Shows Figure 3 A top view schematic diagram of a connection platform;

[0023] Figure 7 Shows Figure 1 Schematic diagram of the three-dimensional structure of the tibial plateau of the knee joint prosthesis;

[0024] Figure 8 Shows Figure 7 A bottom view of the tibial plateau;

[0025] Fig. 9 Shows Figure 7 A schematic top view of the tibial plateau;

[0026] Fig.10 Shows Figure 1 A schematic diagram of the three-dimensional structure of a gasket body of a knee joint prosthesis; and

[0027] Fig.11 Shows Fig.10 A schematic cross-sectional view of a gasket body.

[0028] The above drawings include the following reference numerals:

[0029] 10. Tibial plateau; 11. First arc-shaped groove; 20. Gasket platform; 21. Second arc-shaped groove; 22. Gasket body; 221. First mounting hole; 23. Connecting platform; 231. Cylinder body; 30. Ball bearing; 40. First positioning device; 41. First positioning hole; 42. First positioning column; 50. Second positioning device; 51. Second positioning hole; 52. Second positioning column; 60. Positioning structure. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0032] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0033] In order to increase the smoothness and flexibility of the rotation of the tibial plateau and the spacer platform, such as Figures 1 to 4 As shown, in this embodiment, the knee joint prosthesis includes: a tibial plateau 10, a shim platform 20 and a ball 30. The upper surface of the tibial plateau 10 is provided with a first arc groove 11. The shim platform 20 is rotatably mounted on the tibial plateau 10, and the lower surface of the shim platform 20 is provided with a second arc groove 21 corresponding to the first arc groove 11. The ball 30 is installed in the first arc groove 11 and the second arc groove 21, and the tibial plateau 10 supports the shim platform 20 through the ball 30.

[0034] By applying the technical solution of this embodiment, the shim platform 20 is installed on the tibial plateau 10, the upper surface of the tibial plateau 10 is provided with a first arc groove 11, and the lower surface of the shim platform 20 is provided with a second arc groove 21, and the first arc groove 11 and the second arc groove 21 are provided correspondingly. The ball 30 is installed in the first arc groove 11 and the second arc groove 21. The ball 30 can be one or more, and the ball 30 does not fill the first arc groove 11 and the second arc groove 21. The ball 30 can slide in the first arc groove 11 and the second arc groove 21. The ball 30 can reduce the friction between the tibial plateau 10 and the shim platform 20, and at the same time, the ball 30 can limit the rotation angle of the shim platform 20 relative to the tibial plateau 10 while sliding in the first arc groove 11 and the second arc groove 21. Therefore, the technical solution of this embodiment effectively solves the problem of poor flexibility of knee joint prosthesis in the related art.

[0035] Considering that the gasket body 22 is easy to wear, a connecting platform 23 is provided. Figure 1 and Figure 2 As shown, in this embodiment, the gasket platform 20 includes a gasket body 22 and a connecting platform 23, the connecting platform 23 is located below the gasket body 22, the connecting platform 23 is connected to the bottom of the gasket platform 20, and the second arc groove 21 is arranged on the lower surface of the connecting platform 23. The arrangement of the connecting platform 23 effectively increases the structural strength of the gasket platform 20, and under the action of the connecting platform 23, the wear of the gasket body 22 is effectively avoided. The connecting platform 23 can effectively support the gasket body 22. The gasket body 22 is made of ultra-high molecular weight polyethylene or highly cross-linked polyethylene, the bottom surface of the gasket body 22 is provided with a hole for assembly with the connecting platform 23, and the upper surface of the gasket body 22 is an articular surface that cooperates with the femoral condyle.

[0036] In order to improve the smoothness of rotation between the tibial plateau 10 and the shim platform 20. Figure 1As shown, in this embodiment, there are multiple balls 30, and the multiple balls 30 are installed in the first arc groove 11 and the second arc groove 21. The sum of the diameters of the multiple balls 30 is less than the length of the first arc groove 11, and the sum of the diameters of the multiple balls 30 is less than the length of the second arc groove 21. The balls 30 roll in the first arc groove 11 and the second arc groove 21. After the balls 30 are installed in the first arc groove 11 and the second arc groove 21, there is a gap between the first arc groove 11 and the second arc groove 21, and the gap allows the balls 30 to roll. Under the action of the balls 30, the first arc groove 11 can be offset from the second arc groove 21, so that the connecting platform 23 and the tibial platform 10 can rotate relative to each other. After the balls 30 are misaligned in the first arc groove 11 and the second arc groove 21, multiple balls 30 can gather at one end of the first arc groove 11 and the second arc groove 21. In this way, due to the action of the balls 30, the first arc groove 11 and the second arc groove 21 can be limited to prevent the connecting platform 23 and the tibial platform 10 from rotating excessively.

[0037] The first arc groove 11 and the second arc groove 21 are both concentric grooves, and the grooves are non-through structures, consisting of no less than two sections of grooves. The ball 30 in this embodiment is a ball bearing, and of course it can also be a tapered roller bearing.

[0038] like Figures 1 to 9 As shown, in this embodiment, there are two first arc grooves 11 and two second arc grooves 21, the two first arc grooves 11 are symmetrical with respect to the center of the tibial plateau 10, and the two second arc grooves 21 are symmetrical with respect to the center of the connecting platform 23. The symmetrical arrangement of the two first arc grooves 11 and the second arc grooves 21 can make the support of the shim platform 20 by the ball 30 more stable, and prevent the shim platform 20 from tilting.

[0039] Of course, in an embodiment not shown in the figure, the number of the first arc-shaped grooves can also be set to three, four or more, and the second arc-shaped grooves are set corresponding to the first arc-shaped grooves.

[0040] In an embodiment not shown in the figure, the groove widths of the plurality of first arc grooves are different, and the second arc grooves are arranged corresponding to the first arc grooves. With the difference in the groove widths, balls of different diameters are arranged in the first arc grooves and the second arc grooves of different groove widths. The balls of large diameter mainly play the role of limiting the excessive rotation of the connecting platform and the tibial plateau, and the balls of small diameter mainly play the role of supporting the connecting platform. The number of balls of small diameter is greater than the number of balls of large diameter, so that the number of balls in the first arc groove and the second arc groove is large, which can effectively improve the smoothness of the rotation between the connecting platform and the tibial plateau.

[0041] Specifically, there are two first arcuate grooves, namely a first arcuate groove segment and a second arcuate groove segment. The width and depth of the first arcuate groove segment are greater than the width and depth of the second arcuate groove segment, and the diameter of the balls in the first arcuate groove segment is greater than the diameter of the balls in the second arcuate groove segment.

[0042] In order to connect the gasket body 22 and the connecting platform 23, the gasket body 22 and the connecting platform 23 are prevented from being separated. Figure 1 , Figure 3 , Figure 5 , Figure 6 as well as Fig.10 As shown, in the present embodiment, a first positioning device 40 is provided between the gasket body 22 and the connecting platform 23, and the first positioning device 40 includes a first positioning hole 41 and a first positioning column 42, the first positioning hole 41 is provided on the gasket body 22, the first positioning column 42 is provided on the connecting platform 23, and the first positioning column 42 and the first positioning hole 41 are plugged and transitionally matched. The transitional fit can make the connection between the gasket body 22 and the connecting platform 23 more stable. After the knee joint prosthesis is implanted into the human body, the gasket platform 20 and the tibial platform 10 will be squeezed by the human bone structure, therefore, the gasket body 22 and the connecting platform 23 do not need to use fasteners. In this way, only the connection method of transitional fit is used, which can reduce the processing difficulty and improve the processing efficiency.

[0043] like Figures 1 to 9 As shown, in this embodiment, a second positioning device 50 is provided between the tibial plateau 10 and the gasket platform 20. The second positioning device 50 is located at the center of the tibial plateau 10 and the gasket platform 20. The second positioning device 50 includes a second positioning hole 51 and a second positioning column 52. The second positioning column 52 is provided on the tibial plateau 10, and the second positioning hole 51 is provided on the gasket platform 20. The second positioning column 52 and the second positioning hole 51 are plugged and transitionally matched. The plug-in matching structure is simple and has a good matching effect. At the same time, it can play a limiting role to prevent the connecting platform 23 from being separated from the tibial plateau 10. The second positioning column 52 is the axis of rotation of the connecting platform 23.

[0044] like Fig.10 and Fig.11 As shown, in this embodiment, a first mounting hole 221 is provided at the center of the gasket body 22, a barrel portion 231 is provided on the connecting platform 23, a second mounting hole is provided in the barrel portion 231, the barrel portion 231 is inserted into the first mounting hole 221, and the second mounting hole forms a second positioning hole 51. The arrangement of the barrel portion 231 can improve the structural strength of the connecting platform 23, and at the same time, the barrel portion 231 can play a guiding role in the process of inserting the barrel portion 231 into the first mounting hole 221. The second positioning column 52 is inserted into the interior of the barrel portion 231, and the barrel portion 231 can protect the gasket body and prevent the gasket body from being worn and generating debris.

[0045] To avoid friction, Figures 1 to 7 As shown, in this embodiment, the surface roughness of the upper surface of the tibial plateau 10, the lower surface of the connecting platform 23, the outer surface of the second positioning column 52, and the inner surface of the second positioning hole 51 are all less than Ra0.16. The upper surface of the tibial plateau 10, the lower surface of the connecting platform 23, the outer surface of the second positioning column 52, and the inner surface of the second positioning hole 51 are all mirror-polished, which can improve the smoothness of rotation and reduce friction.

[0046] In order to avoid relative rotation between the tibial plateau and the human bone structure after implantation, Figure 7 and Figure 8 As shown, in this embodiment, a positioning structure 60 is provided on the lower surface of the tibial plateau 10. The positioning structure 60 includes a plurality of positioning rods, which are inserted into the human bone structure after the knee joint prosthesis is implanted in the human body. A column is also provided on the lower surface of the tibial plateau 10, and the column is also inserted into the human bone structure. The provision of a plurality of positioning rods can prevent the tibial plateau from rotating relative to the human bone structure, thereby making the structure of the tibial plateau more stable. In this embodiment, the lower surface of the tibial plateau, the outer surface of the positioning rods, and the outer surface of the columns are all provided with bioactive substances, so that the human bone structure can be better fixed to the tibial plateau.

[0047] Of course, in order to improve the fixation effect of the tibial plateau, a plurality of through holes are provided on the column. The provision of the through holes can allow the human bone structure to grow in better and can effectively achieve biological fixation.

[0048] like Figures 1 to 9 As shown, in this embodiment, the material of the tibial platform 10, the connecting platform 23 and the ball 30 is metal. Metal material is not easy to be damaged and has good structural strength. Of course, it can also be ceramic. The effect of ceramic is the same as that of the above-mentioned metal material.

[0049] There is a relative rotation between the tibial plateau 10 and the gasket platform 20, and the relative rotation range of the tibial plateau 10 and the gasket platform 20 is determined by the length of the first arc groove 11, the length of the second arc groove 21 and the number of balls 30. After implantation into the human body, the muscles drive the knee joint to produce internal and external rotation movements similar to the natural knee joint accompanied by knee flexion movements, thereby enhancing the patient's proprioception. In addition, since a ball bearing structure is added between the tibial plateau 10 and the gasket platform 20, the friction rate between the interfaces is reduced, thereby extending the service life of the prosthesis.

[0050] The ball bearing is different from the industrial ring structure. Instead, it embeds a plurality of discrete balls into the first arc groove 11 and the second arc groove 21 on the tibial plateau 10 and the spacer plateau 20. In addition, the balls only fill part of the space of the first arc groove 11 and the second arc groove 21 of the tibial plateau, so that the first arc groove 11 and the second arc groove 21 have a certain rotation angle range, which plays a role in reducing the wear of the prosthesis during the rotation movement of the knee joint and limiting the relative rotation angle of the tibial plateau 10 and the spacer plateau 20.

[0051] The technical solution of the present application can effectively improve the flexibility of the knee joint prosthesis, reduce the wear of the knee joint prosthesis, and improve the patient's proprioception by providing the first arc groove 11, the second arc groove 21 and the ball 30.

[0052] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0053] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0054] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0055] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A knee joint prosthesis, characterized in that: include: A tibial plateau (10), wherein the upper surface of the tibial plateau (10) is provided with a first arc-shaped groove (11); A shim platform (20), the shim platform (20) being rotatably mounted on the tibial platform (10), and a second arc-shaped groove (21) corresponding to the first arc-shaped groove (11) being provided on the lower surface of the shim platform (20); A ball (30) is installed in the first arc-shaped groove (11) and the second arc-shaped groove (21), and the tibial platform (10) supports the shim platform (20) through the ball (30); The gasket platform (20) comprises a gasket body (22) and a connecting platform (23), wherein the connecting platform (23) is located below the gasket body (22), the connecting platform (23) is connected to the bottom of the gasket platform (20), and the second arc groove (21) is arranged on the lower surface of the connecting platform (23); There are a plurality of the first arc-shaped grooves (11), and a plurality of the second arc-shaped grooves (21); The first arcuate groove (11) comprises a first arcuate groove segment and a second arcuate groove segment, the width and depth of the first arcuate groove segment are greater than the width and depth of the second arcuate groove segment, and the diameter of the ball (30) located in the first arcuate groove segment is greater than the diameter of the ball (30) in the second arcuate groove segment.

2. The knee joint prosthesis according to claim 1, characterized in that: There are a plurality of balls (30), and the plurality of balls (30) are installed in the first arc-shaped groove (11) and the second arc-shaped groove (21). The sum of the diameters of the plurality of balls (30) is smaller than the length of the first arc-shaped groove (11), and the sum of the diameters of the plurality of balls (30) is smaller than the length of the second arc-shaped groove (21).

3. The knee joint prosthesis according to claim 1, characterized in that: The plurality of first arc-shaped grooves (11) are symmetrical relative to the center of the tibial platform (10), and the second arc-shaped grooves (21) are symmetrical relative to the center of the connecting platform (23).

4. The knee joint prosthesis according to claim 1, characterized in that: A first positioning device (40) is arranged between the gasket body (22) and the connecting platform (23), and the first positioning device (40) includes a first positioning hole (41) and a first positioning column (42). One of the first positioning hole (41) and the first positioning column (42) is arranged on the gasket body (22), and the other is arranged on the connecting platform (23). The first positioning column (42) and the first positioning hole (41) are plugged in and transitionally matched.

5. The knee joint prosthesis according to claim 1, characterized in that: A second positioning device (50) is provided between the tibial platform (10) and the gasket platform (20), and the second positioning device (50) is located at the center of the tibial platform (10) and the gasket platform (20). The second positioning device (50) includes a second positioning hole (51) and a second positioning column (52). One of the second positioning column (52) and the second positioning hole (51) is provided on the tibial platform (10), and the other is provided on the gasket platform (20). The second positioning column (52) and the second positioning hole (51) are plugged in and transitionally matched.

6. The knee joint prosthesis according to claim 5, characterized in that: A first mounting hole (221) is provided at the center of the gasket body (22); a barrel portion (231) is provided on the connection platform (23); a second mounting hole is provided in the barrel portion (231); the barrel portion (231) is inserted into the first mounting hole (221); and the second mounting hole forms the second positioning hole (51).

7. The knee joint prosthesis according to claim 5, characterized in that: The surface roughness of the upper surface of the tibial platform (10), the lower surface of the connecting platform (23), the outer surface of the second positioning column (52) and the inner surface of the second positioning hole (51) are all less than or equal to Ra0.

16.

8. The knee joint prosthesis according to claim 1, characterized in that: The lower surface of the tibial plateau (10) is provided with a positioning structure (60).

9. The knee joint prosthesis according to claim 1, characterized in that: The tibial platform (10), the connecting platform (23) and the ball (30) are made of metal or ceramic.

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