Knee joint prosthesis
By designing a composite spherical concave surface on the meniscus pad of the knee prosthesis, simulating the shape of the natural meniscus in the human body, the problem of insufficient movement flexibility and stability in the prior art is solved, and a more natural and comfortable human activities are achieved.
Patent Information
- Application Number
- CN202510316982.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-18
- Publication Date
- 2025-06-27
AI Technical Summary
The meniscus pads in existing knee prostheses have poor motor flexibility and stability when simulating the human body's natural meniscus.
A knee prosthesis is designed, with the surface of the meniscus pad having a composite spherical concave surface, including a spherical concave surface and an ellipsoidal concave surface. These concave structures simulate the morphology of the human body's natural meniscus and improve the matching degree with the femoral condylar prosthesis.
Through the composite spherical concave structure, the movement flexibility and stability of the knee prosthesis are improved, making human activities more natural and comfortable.
Smart Images
Figure CN120203882A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of medical prostheses, and particularly relates to a knee joint prosthesis. Background Art
[0002] The meniscus liner (also known as the tibial spacer or polyethylene spacer) in a knee joint prosthesis is a very important component in knee joint replacement surgery. It is located between the femoral condyle and the tibial plateau, and its main functions are to provide cushioning and support, reduce friction, disperse pressure, and enhance the stability of the knee joint. In related technologies, the surface of the meniscus liner usually has grooves connected to the femoral condyle to enable relative movement between the tibia and the femur. However, the flexibility and stability of the relative movement between the tibia and the femur are poor. Summary of the Invention
[0003] The present invention aims to solve at least one of the technical problems in related technologies to some extent. For this purpose, an embodiment of the present invention provides a knee joint prosthesis, which is beneficial to ensuring the flexibility and stability of human activities.
[0004] The knee joint prosthesis according to the embodiment of the present invention includes a meniscus liner. The surface of the meniscus liner facing the femoral condyle includes an inner side surface and an outer side surface. The inner side surface is used to be matched and connected with the medial femoral condyle, and the outer side surface is used to be matched and connected with the lateral femoral condyle; both the inner side surface and the outer side surface have a composite spherical concave surface, which is formed by overlapping a spherical concave surface and an ellipsoidal concave surface. The composite spherical concave surface has a projection in its depth direction, and on the projection, the ellipsoidal concave surface is located within the outer contour of the spherical concave surface, and the depth of the ellipsoidal concave surface is greater than the depth of the spherical concave surface.
[0005] In the use state of the knee joint prosthesis in this embodiment, the hemispherical protrusion of the femoral condyle is arranged in the composite spherical concave surface of the meniscus liner. The composite spherical concave surface is formed by overlapping a spherical concave surface and an ellipsoidal concave surface. The femoral condyle first contacts the ellipsoidal concave surface. As the flexion amplitude of the human thigh and calf increases, the femoral condyle gradually contacts the spherical concave surface outside the ellipsoidal concave surface. Through the cooperation of the ellipsoidal concave surface and the spherical concave surface, the shape of the natural meniscus of the human body can be better simulated, the matching degree with the femoral condyle prosthesis can be improved, which will neither limit the normal movement of the human body, improve the flexibility of human movement, nor make human activities more stable.
[0006] In this embodiment, the transition region between the ellipsoidal concave surface and the spherical concave surface is smoothly connected.
[0007] In this embodiment, the composite spherical concave surface has a projection in its depth direction, and on the projection,
[0008] The center of the spherical concave surface of the composite spherical concave surface on the outer side is at the intersection of the position offset by a first preset distance outward from the center line in the inner and outer direction of the meniscus pad and the center line in the front and back direction of the meniscus pad;
[0009] And / or, the center of the spherical concave surface of the composite spherical concave surface on the inner side is at the intersection of the position offset by a first preset distance inward from the center line in the inner and outer direction of the meniscus pad and the center line in the front and back direction of the meniscus pad.
[0010] In this embodiment, the first preset distance is L1, and L1 is 15 mm to 25 mm.
[0011] In this embodiment, the composite spherical concave surface has a projection in its depth direction. On the projection,
[0012] The center point of the ellipsoidal concave surface of the composite spherical concave surface on the outer side is at a position offset outward by a second preset distance from the center of the spherical concave surface of the outer composite spherical concave surface;
[0013] And / or, the center point of the ellipsoidal concave surface of the composite spherical concave surface on the inner side is at a position offset inward by a second preset distance from the center of the spherical concave surface of the inner composite spherical concave surface.
[0014] In this embodiment, the second preset distance is L2, and L2 is 0 mm to 10 mm.
[0015] In this embodiment, the composite spherical concave surface has a projection in its depth direction. On the projection,
[0016] The diameter of the spherical concave surface of the composite spherical concave surface on the outer side is D1, D1 is 20 mm to 60 mm, the length of the major axis of the ellipsoidal concave surface is A1, A1 is 20 mm to 60 mm, and the size of A1 matches the size of D1;
[0017] And / or, the diameter of the spherical concave surface of the composite spherical concave surface on the inner side is D2, D2 is 30 mm to 70 mm, the length of the major axis of the ellipsoidal concave surface is A3, A3 is 30 mm to 70 mm, and the size of A3 matches the size of D2.
[0018] In this embodiment, the composite spherical concave surface has a projection in its depth direction. On the projection,
[0019] The length of the minor axis of the ellipsoidal concave surface of the composite spherical concave surface on the outer side is A2, A2 is 10 mm to 30 mm;
[0020] And / or, the length of the minor axis of the ellipsoidal concave surface of the composite spherical concave surface on the inner side is A4, and A4 is 20 mm to 40 mm.
[0021] In this embodiment, the composite spherical concave surface has a projection in its depth direction. On this projection,
[0022] In the minor axis direction of the ellipsoidal concave surface, the distance between the contour of the ellipsoidal concave surface of the inner side close to the outer side and the contour of the adjacent spherical concave surface is 1 mm to 10 mm;
[0023] And / or, in the minor axis direction of the ellipsoidal concave surface, the distance between the contour of the ellipsoidal concave surface of the outer side close to the inner side and the contour of the adjacent spherical concave surface is 1 mm to 10 mm.
[0024] In this embodiment, the knee joint prosthesis further includes a femoral prosthesis and a tibial prosthesis. The femoral prosthesis includes a medial condyle and a lateral condyle. The medial condyle cooperates with the inner side, the lateral condyle cooperates with the outer side, and the side of the meniscus liner away from the femoral prosthesis is connected to the tibial prosthesis. Description of the Drawings
[0025] Figure 1 is a schematic structural view of the knee joint prosthesis according to an embodiment of the present invention Figure 1 .
[0026] Figure 2 is a schematic structural view of the knee joint prosthesis according to an embodiment of the present invention Figure 2 .
[0027] Figure 3 is a cross-sectional view of the knee joint prosthesis according to an embodiment of the present invention.
[0028] Figure 4 is an axonometric view of the knee joint prosthesis according to an embodiment of the present invention.
[0029] Reference Signs:
[0030] 1. Meniscus liner; 11a. Composite spherical concave surface on the outer side; 11b. Composite spherical concave surface on the inner side; 111. Spherical concave surface; 112. Ellipsoidal concave surface. Detailed Embodiments
[0031] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present invention and should not be construed as a limitation of the present invention.
[0032] In this embodiment, as Figures 1 to 4As shown, the knee joint prosthesis includes a meniscus liner 1. The surface of the meniscus liner 1 facing the femoral condyles (not shown in the figure) includes an inner side and an outer side. The inner side is used to be matched and connected with the medial femoral condyle, and the outer side is used to be matched and connected with the lateral femoral condyle. Both the inner side and the outer side have a compound spherical concave surface, which is formed by overlapping a spherical concave surface 111 and an ellipsoidal concave surface 112. The compound spherical concave surface has a projection in its depth direction. In the projection, the ellipsoidal concave surface 112 is located within the outer contour of the spherical concave surface 111, and the depth of the ellipsoidal concave surface 112 is greater than the depth of the spherical concave surface 111.
[0033] Specifically, the major axis direction of the ellipsoidal concave surface 112 extends along the front-back direction of the meniscus liner 1, which can make the movement amplitude in the front-back direction of the human body larger and better meet the movement needs of the human body.
[0034] In the use state of the knee joint prosthesis in this embodiment, the hemispherical protrusion of the femoral condyle is arranged in the compound spherical concave surface of the meniscus liner 1. The compound spherical concave surface is formed by overlapping a spherical concave surface 111 and an ellipsoidal concave surface 112. The femoral condyle first contacts the ellipsoidal concave surface 112. As the flexion amplitude of the human thigh and calf increases, the femoral condyle gradually contacts the spherical concave surface 111 outside the ellipsoidal concave surface 112. Through the cooperation of the ellipsoidal concave surface 112 and the spherical concave surface 111, it can better simulate the shape of the natural meniscus of the human body, improve the matching degree with the femoral condyle prosthesis, neither limit the normal movement of the human knee joint, improve the flexibility of the human knee joint movement, nor make the human activities more stable.
[0035] In this embodiment, the transition region between the ellipsoidal concave surface 112 and the spherical concave surface 111 is smoothly connected.
[0036] By making the transition region between the ellipsoidal concave surface 112 and the spherical concave surface 111 smoothly connected, it can ensure continuous curvature change, which is beneficial to make the femoral condyle rotate more smoothly in the compound spherical concave surface, thereby improving the stability of the prosthesis and enhancing the user experience.
[0037] In this embodiment, as Figure 1 and Figure 3 shown, the knee joint prosthesis further includes a femoral prosthesis (not shown in the figure) and a tibial prosthesis (not shown in the figure). The femoral prosthesis includes a medial condyle and a lateral condyle. The medial condyle cooperates with the inner side, and the lateral condyle cooperates with the outer side. The side of the meniscus liner away from the femoral prosthesis is connected to the tibial prosthesis.
[0038] It can be understood that the femoral prosthesis includes a lateral condyle and a medial condyle. By providing an outer side and an inner side on the meniscus liner 1, the outer side corresponds to the lateral condyle, and the inner side corresponds to the medial condyle, so as to ensure the range of motion of the knee joint through the synergistic effect of the two-by-two cooperation.
[0039] In this embodiment, as Figure 1 shown, the composite spherical concave surface has a projection in its depth direction. On the projection, the center of the spherical concave surface 111 of the composite spherical concave surface 11a on the outer side is at the intersection of the position offset by a first preset distance outward from the center line in the inner and outer directions of the meniscus pad 1 and the center line in the front and back directions of the meniscus pad 1.
[0040] In this embodiment, the first preset distance is L1, and L1 is 15 mm to 25 mm. For example, the first preset distance L1 can be 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 21 mm, 22 mm, 23 mm, 24 mm, or 25 mm, etc. The specific value of the first preset distance L1 varies due to individual knee joint morphology differences. Therefore, the value of the first preset distance L1 can be correspondingly set according to the actual needs of the individual knee joint, and no limitation is made here.
[0041] It can be understood that based on the center line in the inner and outer directions of the meniscus pad 1 and the center line in the front and back directions of the meniscus pad 1, and by setting the center of the spherical concave surface 111 of the composite spherical concave surface 11a on the outer side according to individual knee joint differences, the position of the spherical concave surface 111 can be precisely controlled by precisely controlling the center position, thereby improving the matching degree between the prosthesis and the human body, and further improving the comfort of the prosthesis.
[0042] In this embodiment, as Figure 1 shown, the composite spherical concave surface has a projection in its depth direction. On the projection, the center of the spherical concave surface 111 of the composite spherical concave surface 11b on the inner side is at the intersection of the position offset by the first preset distance inward from the center line in the inner and outer directions of the meniscus pad 1 and the center line in the front and back directions of the meniscus pad 1.
[0043] In this embodiment, as Figure 1 shown, the first preset distance is L1, and L1 is 15 mm to 25 mm. For example, the first preset distance L1 can be 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 21 mm, 22 mm, 23 mm, 24 mm, or 25 mm, etc. The specific value of the first preset distance L1 varies due to individual knee joint morphology differences. Therefore, the value of the first preset distance L1 can be correspondingly set according to the actual needs of the individual knee joint, and no limitation is made here.
[0044] Similarly, taking the center line in the inner-outer direction and the center line in the front-back direction of the meniscus pad 1 as a reference, and setting the center of the spherical concave surface 111 of the compound spherical concave surface 11b on the inner side according to the differences of individual knee joints. By precisely controlling the position of the center, the position of the spherical concave surface 111 can be precisely controlled, thereby improving the matching degree between the prosthesis and the human body, and further improving the comfort of the prosthesis.
[0045] In this embodiment, the compound spherical concave surface has a projection in its depth direction. On the projection, the center point of the ellipsoidal concave surface 112 of the compound spherical concave surface 11a on the outer side is at a position where it is offset by a second preset distance outward from the center of the spherical concave surface 111 of the compound spherical concave surface 11a on the outer side.
[0046] In this embodiment, as Figure 1 shown, the second preset distance is L2, and L2 is 0 mm to 10 mm. It should be noted that when L2 is 0, the center points of the spherical concave surface 111 and the ellipsoidal concave surface 112 coincide. For example, the second preset distance L2 can be 0 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm or 10 mm, etc. The specific value of the second preset distance L2 can be selected according to the actual needs of individual knee joint movement and is not limited herein.
[0047] It can be understood that by offsetting the center point of the ellipsoidal concave surface 112 of the compound spherical concave surface 11a on the outer side relative to the center of the spherical concave surface 111 of the compound spherical concave surface 11a on the outer side by the second preset distance, and the specific value of the second preset distance can be set according to actual needs. By precisely controlling the position of the knee joint, it is beneficial to optimize the matching degree between the femoral condyle and the meniscus pad 1 and reduce friction and wear.
[0048] In this embodiment, as Figure 3 shown, the compound spherical concave surface has a projection in its depth direction. On the projection, the center point of the ellipsoidal concave surface 112 of the compound spherical concave surface 11b on the inner side is at a position where it is offset by a second preset distance inward from the center of the spherical concave surface 111 of the compound spherical concave surface 11b on the inner side.
[0049] In this embodiment, as Figure 3 shown, the second preset distance is L2, and L2 is 0 mm to 10 mm. It should be noted that when L2 is 0, the center points of the spherical concave surface 111 and the ellipsoidal concave surface 112 coincide. For example, the second preset distance L2 can be 0 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm or 10 mm, etc. The specific value of the second preset distance L2 can be selected according to the actual needs of individual knee joint movement and is not limited herein.
[0050] Similarly, by shifting the center point of the ellipsoidal concave surface 112 of the composite spherical concave surface 11b on the inner side relative to the center of the spherical concave surface 111 of the composite spherical concave surface 11b on the inner side by a second preset distance, the specific value of the second preset distance can be set according to actual requirements. By precisely controlling the position of the knee joint, it is beneficial to optimize the matching degree between the femoral condyle and the meniscus pad 1 and reduce friction and wear.
[0051] In this embodiment, as Figure 1 shown, the composite spherical concave surface has a projection in its depth direction. On the projection, the diameter of the spherical concave surface 111 of the composite spherical concave surface 11a on the outer side is D1, D1 is 20 mm to 60 mm, the length of the major axis of the ellipsoidal concave surface 112 is A1, A1 is 20 mm to 60 mm, and the size of A1 matches the size of D1.
[0052] For example, D1 can be 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, 55 mm or 60 mm. If the value of D1 is too large or too small, it does not match the natural shape of the human knee joint and is not conducive to meeting the actual movement needs of the human body. A1 can be 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, 55 mm or 60 mm. The size of A1 matches the size of D1, that is, the size of A1 increases with the increase of D1 and decreases with the decrease of D1. Those skilled in the art can set the size of A1 according to the size of D1, and the specific values of D1 and A1 are not limited here.
[0053] It should be noted that the range of the diameter D1 of the spherical concave surface 111 of the composite spherical concave surface 11a on the outer side is set to 20 mm to 60 mm, and the specific value of D1 can be selected within this range according to the natural shape of the human knee joint. At the same time, the size of A1 matches the size of D1, and the value of A1 can be selected according to the size of D1, which is beneficial to improve the adaptability.
[0054] In this embodiment, the composite spherical concave surface has a projection in its depth direction. On the projection, both ends of the major axis of the ellipsoidal concave surface 112 of the composite spherical concave surface 11a on the outer side are located on the contour of the spherical concave surface 111 of the composite spherical concave surface 11a on the outer side.
[0055] It should be noted that the major axis direction of the ellipsoidal concave surface 112 of the composite spherical concave surface 11a on the outer side extends along the front - rear direction of the meniscus pad 1. By locating both ends of the major axis of the ellipsoidal concave surface 112 on the contour of the spherical concave surface 111 of the composite spherical concave surface 11a on the outer side, while meeting the normal movement requirements of the human knee joint in the front - rear direction, the overall structure of the composite spherical concave surface is made more concise.
[0056] In this embodiment, as Figure 1 shown, in the projection of the composite spherical concave surface in its depth direction, the length of the minor axis of the ellipsoidal concave surface 112 of the composite spherical concave surface 11a on the outer side is A2, and A2 is 10 mm to 30 mm.
[0057] For example, A2 can be 10 mm, 15 mm, 20 mm, 25 mm, or 30 mm, etc. If the value of A2 is too large or too small, it is not conducive to meeting the needs of human activities. Those skilled in the art can select the value of A2 according to the natural shape of the human knee joint, and no limitation is imposed here.
[0058] It can be understood that by setting the length A2 of the minor axis of the ellipsoidal concave surface 112 of the composite spherical concave surface 11a on the outer side to 10 mm to 30 mm, the needs of human activities can be met, and at the same time, by selecting a matching value within this range according to the natural shape of the human body, it is beneficial to improve the adaptability.
[0059] In this embodiment, the composite spherical concave surface has a projection in its depth direction. In the projection, in the minor axis direction of the ellipsoidal concave surface 112, the distance between the contour of the ellipsoidal concave surface 112 on the outer side close to the inner side and the contour of the adjacent spherical concave surface is 1 mm to 10 mm.
[0060] Specifically, by setting the distance between the contour of the ellipsoidal concave surface 112 on the outer side close to the inner side and the contour of the adjacent spherical concave surface to 1 mm to 10 mm, a certain first contact space can be left for the spherical concave surface 111 of the composite spherical concave surface 11a on the outer side in the inner and outer directions of the meniscus pad 1, that is, the length of the first contact space is AA1, and AA1 is 1 mm to 10 mm. For example, AA1 can be 1 mm, 3 mm, 5 mm, 8 mm, or 10 mm, etc. If the value of AA1 is too small, the installation requirements of the lateral femoral condyle cannot be met. If the value of AA1 is too large, the rotational stability of the lateral femoral condyle will be affected. In this embodiment, by setting AA1 to 1 mm to 10 mm, while meeting the installation requirements of the lateral femoral condyle, when the lateral femoral condyle rotates inward or outward, it contacts the first contact space, which is beneficial to making the femoral condyle rotate more stably, thereby improving the stability of knee joint movement.
[0061] In this embodiment, as Figure 3 shown, in the projection of the composite spherical concave surface in its depth direction, the diameter of the spherical concave surface 111 of the composite spherical concave surface 11b on the inner side is D2, D2 is 30 mm to 70 mm, the length of the major axis of the ellipsoidal concave surface 112 is A3, A3 is 30 mm to 70 mm, and the size of A3 matches that of D2.
[0062] For example, D2 can be 30mm, 35mm, 40mm, 45mm, 50mm, 55mm or 60mm. If the value of D1 is too large or too small, it does not match the natural shape of the human knee joint and is not conducive to meeting the actual movement needs of the human body. A2 can be 30mm, 35mm, 40mm, 45mm, 50mm, 55mm or 60mm. The size of A2 matches the size of D2, and the size of A3 increases with the increase of D2 and decreases with the decrease of D2. Those skilled in the art can set the size of A3 according to the size of D2, and the specific values of D2 and A3 are not limited herein.
[0063] Similarly, the diameter D2 of the spherical concave surface 111 of the compound spherical concave surface 11b on the inner side is set in the range of 30mm to 60mm. The specific value of D2 can be selected within this range according to the natural shape of the human knee joint, which is beneficial to improving the adaptability. At the same time, the size of A3 matches the size of D2, and the value of A3 can be selected according to the size of D2, which is beneficial to improving the adaptability.
[0064] In this embodiment, as Figure 3 shown, the compound spherical concave surface has a projection in its depth direction. On the projection, both ends of the long axis of the ellipsoidal concave surface 112 of the compound spherical concave surface 11b on the inner side are located on the contour of the spherical concave surface 111 of the compound spherical concave surface 11b on the inner side.
[0065] It should be noted that the long axis direction of the ellipsoidal concave surface 112 of the compound spherical concave surface 11b on the inner side extends along the front-back direction of the meniscus liner 1. Both ends of the long axis of the ellipsoidal concave surface 112 are located on the contour of the spherical concave surface 111 of the compound spherical concave surface 11b on the inner side, while meeting the normal movement requirements of the human knee joint in the front-back direction, making the overall structure of the compound spherical concave surface simpler.
[0066] In this embodiment, as Figure 3 shown, in the projection of the compound spherical concave surface in its depth direction, the length of the short axis of the ellipsoidal concave surface 112 of the compound spherical concave surface 11b on the inner side is A4, and A4 is 20mm to 40mm.
[0067] For example, the length of the short axis A4 of the ellipsoidal concave surface 112 of the compound spherical concave surface 11b on the inner side can be 20mm, 22mm, 25mm, 27mm, 30mm, 33mm, 35mm, 37mm or 40mm, etc., and A4 increases with the increase of A3 and decreases with the decrease of A3. If the length of the short axis A4 of the ellipsoidal concave surface 112 of the compound spherical concave surface 11b on the inner side is too large or too small, it will affect the movement of the femoral condyle. Those skilled in the art can select the value of A4 according to the natural shape of the human knee joint, which is not limited herein.
[0068] It is understandable that by setting the length A4 of the minor axis of the ellipsoidal concave surface 112 of the composite spherical concave surface 11b on the inner side to be 20 mm to 40 mm, the activity requirements of the human body can be met, and at the same time, by selecting a matching value within this range according to the natural form of the human body, it is beneficial to improve the adaptability.
[0069] In this embodiment, in the minor axis direction of the ellipsoidal concave surface 112, the distance between the contour of the ellipsoidal concave surface 112 on the inner side close to the outer side and the contour of the adjacent spherical concave surface 111 is 1 mm to 10 mm.
[0070] Specifically, the distance between the contour of the ellipsoidal concave surface 112 on the inner side close to the outer side and the contour of the adjacent spherical concave surface 111 is 1 mm to 10 mm, so that a certain second contact space is left for the spherical concave surface 111 of the composite spherical concave surface 11b on the inner side, that is, the length of the second contact space is AA2, and AA2 is 1 mm to 10 mm. For example, AA2 can be 1 mm, 3 mm, 5 mm, 8 mm, or 10 mm, etc. If the value of AA2 is too small, the installation requirements of the lateral condyle of the femur cannot be met; if the value of AA2 is too large, the rotational stability of the medial condyle of the femur will be affected. In this embodiment, by setting AA2 to 1 mm to 10 mm, while meeting the installation requirements of the medial condyle of the femur, when the medial condyle of the femur rotates medially or laterally, it contacts with the second contact space, which is beneficial to making the femoral condyle rotate more stably, thereby improving the stability of knee joint movement.
[0071] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention.
[0072] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.
[0073] In the present invention, unless otherwise clearly defined or limited, terms such as "installed", "connected", "joined", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, or communicable with each other; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0074] In the present invention, unless otherwise clearly defined or limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "below" and "beneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.
[0075] In the present invention, terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.
[0076] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.
Claims
1. A knee joint prosthesis, characterized in that: It includes a meniscus pad, the surface of the meniscus pad facing the femoral condyle includes an inner side and an outer side, the inner side is used to match and connect with the medial femoral condyle, and the outer side is used to match and connect with the lateral femoral condyle; the inner side and the outer side both have a composite spherical concave surface, the composite spherical concave surface is formed by overlapping a spherical concave surface and an ellipsoidal concave surface, the composite spherical concave surface has a projection in its depth direction, on the projection, the ellipsoidal concave surface is located within the outer contour of the spherical concave surface, and the depth of the ellipsoidal concave surface is greater than the depth of the spherical concave surface.
2. The knee joint prosthesis according to claim 1, characterized in that: The transition area between the ellipsoidal concave surface and the spherical concave surface is smoothly connected.
3. The knee joint prosthesis according to claim 1, characterized in that: The composite spherical concave surface has a projection in its depth direction, on which, The center of the spherical concave surface of the composite spherical concave surface of the outer side surface is at the intersection of a position offset outward by a first preset distance based on the center line of the meniscus pad in the inner and outer directions and the center line of the meniscus pad in the front-back direction; And / or, the center of the spherical concave surface of the composite spherical concave surface of the inner side surface is at the intersection of a position offset inwardly by a first preset distance based on the center line of the meniscus pad in the inner and outer directions and the center line of the meniscus pad in the front-back direction.
4. The knee joint prosthesis according to claim 3, characterized in that: The first preset distance is L1, and L1 is 15 mm to 25 mm.
5. The knee joint prosthesis according to claim 3, characterized in that: The composite spherical concave surface has a projection in its depth direction, on which, The center point of the ellipsoidal concave surface of the composite spherical concave surface of the outer side surface is located at a position offset outwardly by a second preset distance from the center point of the spherical concave surface of the composite spherical concave surface of the outer side surface; And / or, the center point of the ellipsoidal concave surface of the compound spherical concave surface of the inner side surface is offset inwardly by a second preset distance from the center point of the spherical concave surface of the compound spherical concave surface of the inner side surface.
6. The knee joint prosthesis according to claim 5, characterized in that: The second preset distance is L2, and L2 is 0 mm to 10 mm.
7. The knee joint prosthesis according to claim 3, characterized in that: The composite spherical concave surface has a projection in its depth direction, on which, The diameter of the spherical concave surface of the composite spherical concave surface of the outer side surface is D1, D1 is 20 mm to 60 mm, the length of the major axis of the ellipsoidal concave surface is A1, A1 is 20 mm to 60 mm, and the size of A1 matches the size of D1; And / or, the diameter of the spherical concave surface of the composite spherical concave surface of the inner side surface is D2, D2 is 30mm-70mm, the length of the major axis of the ellipsoidal concave surface is A3, A3 is 30mm-70mm, and the size of A3 matches the size of D2.
8. The knee joint prosthesis according to claim 3, characterized in that: The composite spherical concave surface has a projection in its depth direction, on which, The length of the minor axis of the ellipsoidal concave surface of the composite spherical concave surface of the outer side surface is A2, and A2 is 10 mm to 30 mm; And / or, the length of the minor axis of the ellipsoidal concave surface of the composite spherical concave surface of the inner side surface is A4, and A4 is 20 mm to 40 mm.
9. The knee joint prosthesis according to claim 3, characterized in that: The composite spherical concave surface has a projection in its depth direction, on which, In the direction of the short axis of the ellipsoidal concave surface, the distance between the contour of the ellipsoidal concave surface of the inner side surface close to the outer side surface and the contour of the spherical concave surface adjacent thereto is 1 mm to 10 mm; And / or, in the short axis direction of the ellipsoidal concave surface, the distance between the contour of the ellipsoidal concave surface of the outer side surface close to the inner side surface and the contour of the spherical concave surface adjacent thereto is 1 mm to 10 mm.
10. The knee joint prosthesis according to any one of claims 1 to 9, characterized in that: It also includes a femoral prosthesis and a tibial prosthesis. The femoral prosthesis includes a medial condyle and a lateral condyle. The medial condyle cooperates with the medial surface, and the lateral condyle cooperates with the lateral surface. The side of the meniscus pad away from the femoral prosthesis is connected to the tibial prosthesis.