Knee joint pad and knee joint prosthesis

Abstract

The present invention relates to a knee joint pad and a knee joint prosthesis, the knee joint pad comprising: a medial nest and a lateral nest, at least one of the medial nest and the lateral nest having a plurality of ellipsoidal concave surfaces therein, the outer peripheral contour of the concave surface being elliptical in a projection plane orthogonal to the thickness direction of the knee joint pad, and the concave surface having an outer peripheral contour of the ellipsoidal concave surface being elliptical in a projection plane orthogonal to the thickness direction of the knee joint pad; the long axis of the ellipse extends in the front-back direction of the knee joint pad, the short axis of the ellipse extends in the left-right direction of the knee joint pad, and the ellipse circle centers of the multiple concave faces are arranged at intervals in the front-back direction of the knee joint pad. According to the knee joint pad, the probability that joint movement is limited can be reduced, the stability of a knee joint prosthesis during movement can be improved, and the satisfaction degree of a patient is high.

Description

Technical Field

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

[0002] Knee replacement surgery uses an artificial knee prosthesis to replace diseased articular cartilage and meniscus while retaining normal joint ligaments and other tissues. It has the advantages of less trauma, faster recovery, reduced pain, and a more natural range of motion. Therefore, knee replacement surgery is widely used in knee joint treatment.

[0003] In the related art, the structural design of the knee pad of the knee prosthesis is unreasonable. When patients with the implanted knee prosthesis perform flexion, internal rotation and external rotation, there is a problem of joint restriction, and the stability of the knee prosthesis is poor, which reduces patient satisfaction. Summary of the invention

[0004] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0005] To this end, an embodiment of the present invention provides a knee joint pad, which has a reasonable structural design, can reduce the probability of joint movement restriction, is conducive to improving the stability of the knee joint prosthesis during movement, and has a high patient satisfaction.

[0006] An embodiment of the present invention provides a knee joint prosthesis.

[0007] A knee joint pad according to an embodiment of the present invention comprises: a medial fossa and a lateral fossa, at least one of the medial fossa and the lateral fossa having a plurality of ellipsoidal concave surfaces, and in a projection plane orthogonal to a thickness direction of the knee joint pad, an outer peripheral contour of the concave surfaces is an ellipse, the major axis of the ellipse extending along the anterior-posterior direction of the knee joint pad, the minor axis of the ellipse extending along the lateral direction of the knee joint pad, and the ellipse centers of the plurality of concave surfaces being arranged at intervals along the anterior-posterior direction of the knee joint pad.

[0008] According to the knee joint pad of the embodiment of the present invention, since the outer peripheral contour of the concave surface is an ellipse, and the ellipse centers of the multiple concave surfaces are arranged at intervals along the anterior-posterior direction of the knee joint pad, when the knee joint is in different flexion angles, the femoral prosthesis can contact the concave surfaces at different positions to simulate the movement of the natural knee joint. On the one hand, the contact area between the knee joint pad and the femoral prosthesis is increased, and on the other hand, the probability of joint movement restriction can be reduced, which is beneficial to improving the stability of the knee joint prosthesis during movement, and the patient satisfaction is high.

[0009] In some embodiments, in the medial fossa, the sizes of the minor axes of the ellipses of the outer peripheral contours of the plurality of concavities are the same, and / or, in the lateral fossa, the sizes of the minor axes of the ellipses of the outer peripheral contours of the plurality of concavities are the same.

[0010] In some embodiments, the outer peripheral contour of the concavity in the medial fossa is larger than the outer peripheral contour of the concavity in the lateral fossa.

[0011] In some embodiments, in the medial fossa, there are at least three concave surfaces, and the ellipse centers of the three concave surfaces are arranged at intervals along the anterior-posterior direction of the knee joint pad; and / or, in the lateral fossa, there are at least two concave surfaces, and the two concave surfaces are arranged at intervals along the anterior-posterior direction of the knee joint pad.

[0012] In some embodiments, in the medial fossa, the concave surface includes a first medial concave surface, a second medial concave surface, a third medial concave surface, a fourth medial concave surface and a fifth medial concave surface, the intersection of the median coronal plane of the knee joint liner and the sagittal plane passing through the lowest point of the medial fossa constitutes the ellipse center of the first medial concave surface, the ellipse centers of the second medial concave surface and the third medial concave surface are arranged in front of the ellipse center of the first medial concave surface, and the ellipse centers of the fourth medial concave surface and the fifth medial concave surface are arranged behind the ellipse center of the first medial concave surface; and / or, in the lateral fossa, the concave surface includes a first lateral concave surface, a second lateral concave surface and a third lateral concave surface, the intersection of the median coronal plane of the knee joint liner and the sagittal plane passing through the lowest point of the lateral fossa constitutes the ellipse center of the first lateral concave surface, the ellipse centers of the second lateral concave surface and the ellipse centers of the third lateral concave surface are respectively arranged on the front and back sides of the ellipse center of the first lateral concave surface.

[0013] In some embodiments, in the medial fossa, the dimension of the outer peripheral contour of the concave surface along the left-right direction of the knee joint pad is A1, wherein 20mm≤A1≤40mm; and / or, in the medial fossa, the dimension of the outer peripheral contour of the concave surface along the front-to-back direction of the knee joint pad is B1, wherein 38mm≤B1≤52mm; and / or, in the lateral fossa, the dimension of the outer peripheral contour of the concave surface along the left-right direction of the knee joint pad is A2, wherein 18mm≤A2≤38mm; and / or, in the lateral fossa, the dimension of the outer peripheral contour of the concave surface along the front-to-back direction of the knee joint pad is B2, wherein 35mm≤B2≤50mm.

[0014] In some embodiments, the distance between the median sagittal plane of the knee joint pad and the sagittal plane passing through the lowest point of the medial fossa is L1, wherein 20mm≤L1≤30mm; and / or, the distance between the median sagittal plane of the knee joint pad and the sagittal plane passing through the lowest point of the lateral fossa is L2, wherein 20mm≤L2≤30mm.

[0015] In some embodiments, in the medial fossa, the distance between the centers of the ellipses of each two adjacent concave surfaces along the anterior-posterior direction of the knee joint pad is equal; and / or, in the lateral fossa, the distance between the centers of the ellipses of each two adjacent concave surfaces along the anterior-posterior direction of the knee joint pad is equal.

[0016] In some embodiments, in the medial fossa, the spacing between the centers of the ellipses of two adjacent concave surfaces along the anterior-posterior direction of the knee joint pad is C1, wherein 1mm≤C1≤2mm; and / or, in the lateral fossa, the spacing between the centers of the ellipses of two adjacent concave surfaces along the anterior-posterior direction of the knee joint pad is C2, wherein 2mm≤C2≤4mm.

[0017] A knee joint prosthesis according to another embodiment of the present invention comprises: a femoral prosthesis, wherein the femoral prosthesis comprises a medial condyle and a lateral condyle; and a knee joint liner, wherein the knee joint liner is any one of the knee joint liner described in the embodiments of the present invention, wherein the medial condyle cooperates with the medial fossa, and the lateral condyle cooperates with the lateral fossa.

[0018] According to the knee prosthesis of the embodiment of the present invention, since the outer peripheral contour of the concave surface is an ellipse, and the ellipse centers of the multiple concave surfaces are arranged at intervals along the anterior-posterior direction of the knee joint pad, when the knee joint is in different flexion angles, the femoral prosthesis can contact the concave surfaces at different positions to simulate the movement of the natural knee joint. On the one hand, the contact area between the knee joint pad and the femoral prosthesis is increased, and on the other hand, the probability of joint movement restriction can be reduced, which is beneficial to improving the stability of the knee prosthesis during movement, and the patient satisfaction is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 4 is a top view of a knee joint pad according to an embodiment of the present invention.

[0020] Figure 2 4 is a cross-sectional view of the medial socket of a knee joint pad according to an embodiment of the present invention.

[0021] Figure 3 FIG. 1 is a simplified diagram of a top view of the medial socket of a knee liner according to an embodiment of the present invention.

[0022] Figure 4 4 is a cross-sectional view of the lateral socket of a knee joint pad according to an embodiment of the present invention.

[0023] Figure 5 FIG. 1 is a simplified diagram of a top view of a lateral socket of a knee liner according to an embodiment of the present invention.

[0024] Figure 6 Schematic diagram of the structure of a knee joint pad according to an embodiment of the present invention.

[0025] Reference numerals: 100. Knee pads; 110, medial fossa; 120, lateral fossa; 101, concave surface; 1011, first inner concave surface; 1012, second inner concave surface; 1013, third inner concave surface; 1014, fourth inner concave surface; 1015, fifth inner concave surface; 1016, first outer concave surface; 1017, second outer concave surface; 1018, third outer concave surface. DETAILED DESCRIPTION

[0026] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0027] In order to better explain and illustrate the technical solution of the present invention, the directions and the like involved in the present invention are explained and illustrated in combination with the conventional description method in the art.

[0028] In the field of anatomy and medical devices, directions and planes such as inside, outside, anterior, posterior, distal, proximal, sagittal, coronal, and cross-sectional planes have specific meanings and are well known to technicians in this field. Unless otherwise specified, these terms refer to the meanings recognized by technicians in this field.

[0029] Usually, when describing the human body, joints or prostheses, the following three sections are usually involved: sagittal plane, coronal plane and cross-sectional plane. Among them, the sagittal plane refers to the longitudinal section that divides the human body or joint into left and right parts from the front-to-back direction. Among them, the sagittal plane passing through the center of the human body is the median sagittal plane, which divides the human body into two equal parts on the left and right. The coronal plane refers to the longitudinal section that divides the human body or joint into front and back parts from the left and right directions. The coronal plane is perpendicular to the sagittal plane. The cross-sectional plane is a plane parallel to the ground plane that divides the human body or joint into upper and lower parts. The cross-sectional plane is perpendicular to the coronal and sagittal planes.

[0030] It is understood that when describing the knee joint or the knee joint prosthesis, the sagittal plane, the coronal plane and the cross-section all refer to the section when a person is standing normally upright, at which time the knee joint has a flexion angle of 0°. The section may change when the knee joint or the knee joint prosthesis is extended or flexed, or when the posture of the human body is adjusted.

[0031] Usually, when describing the human body, joints or prostheses, the following three different directions are involved: near and far, inside and outside, and front and back. Among them, the distal end refers to the end of the human body or joint that is relatively far from the trunk. The proximal end refers to the side of the human body or joint that is relatively close to the trunk. The medial side refers to the side that is relatively close to the median sagittal plane of the human body. The lateral side refers to the side that is relatively far from the median sagittal plane of the human body. The anterior side refers to the end on the sagittal plane that is relatively close to the abdomen. The posterior side refers to the end on the sagittal plane that is relatively close to the back.

[0032] Please refer to the following Figures 1 to 6 A knee joint pad and a knee joint prosthesis according to embodiments of the present invention are described.

[0033] like Figures 1 to 5 As shown, the knee joint pad 100 of the embodiment of the present invention includes a medial fossa 110 and a lateral fossa 120, at least one of the medial fossa 110 and the lateral fossa 120 has a plurality of ellipsoidal concave surfaces 101, and in a projection plane orthogonal to the thickness direction of the knee joint pad 100, the outer peripheral contour of the concave surface 101 is an ellipse, the major axis of the ellipse extends along the front-to-back direction of the knee joint pad 100, and the minor axis of the ellipse extends along the left-to-right direction of the knee joint pad 100, and the ellipse centers of the plurality of concave surfaces 101 are arranged at intervals along the front-to-back direction of the knee joint pad 100.

[0034] It can be understood that the chamber enclosed by the medial fossa 110 and / or the lateral fossa 120 is generally an ellipsoidal cavity, and in the projection plane orthogonal to the thickness direction of the knee joint pad 100, the outer peripheral contour of the concave surface 101 of the medial fossa 110 and / or the concave surface 101 of the lateral fossa 120 is an ellipse.

[0035] For example, Figure 1 and Figure 3 As shown, the medial socket 110 has a plurality of ellipsoidal concave surfaces 101 , and the elliptical centers of the plurality of concave surfaces 101 are arranged at intervals along the front-back direction of the knee joint liner 100 .

[0036] For example, Figure 1 and Figure 5 As shown, the lateral socket 120 has a plurality of ellipsoidal concave surfaces 101 , and the elliptical centers of the plurality of concave surfaces 101 are arranged at intervals along the front-to-back direction of the knee joint liner 100 .

[0037] According to the knee joint pad 100 of the embodiment of the present invention, since the outer peripheral contour of the concave surface 101 is elliptical, and the elliptical centers of the multiple concave surfaces 101 are arranged at intervals along the front-to-back direction of the knee joint pad 100, when the knee joint is in different flexion angles, the femoral prosthesis can contact the concave surfaces 101 at different positions to simulate the movement of the natural knee joint. On the one hand, the contact area between the knee joint pad 100 and the femoral prosthesis is increased, and on the other hand, the probability of joint movement restriction can be reduced, which is beneficial to improving the stability of the knee joint prosthesis during movement, and the patient satisfaction is high.

[0038] like Figure 2 and Figure 3 As shown, the medial fossa 110 is taken as an example. The centers of the elliptical outlines of the multiple concave surfaces 101 in the medial fossa 110 are arranged at intervals along the front-to-back direction of the knee joint pad 100, the major axis of the elliptical outline extends along the front-to-back direction of the knee joint pad 100, and the minor axis of the elliptical outline extends along the left-right direction of the knee joint pad 100, so that the contact area between the medial condyle of the femoral prosthesis and the medial fossa 110 of the knee joint pad 100 is large. When the femoral prosthesis flexes with the movement of the knee joint, the medial condyle can be displaced in the front-to-back direction to cooperate with the concave surfaces 101 at different positions of the medial fossa 110, thereby imitating the movement characteristics of the natural knee joint, allowing the patient to forget joint replacement.

[0039] The knee joint pad 100 of the embodiment of the present invention adopts the above-mentioned structural design for the medial fossa 110 to realize the concept of quasi-medial axis. The structure is consistent with the kinematics of the human knee joint. The medial axis motion design imitates the motion characteristics of the natural knee joint, especially the motion mode with the medial fossa 110 as the axis during flexion. This design not only improves the stability of the knee joint, but also enhances the patient's satisfaction.

[0040] Alternatively, if Figure 1 As shown, the outer peripheral contour of the concave surface 101 in the medial fossa 110 is larger than the outer peripheral contour of the concave surface 101 in the lateral fossa 120. It can be understood that the contact area between the concave surface 101 of the medial fossa 110 and the medial condyle is larger than the contact area between the concave surface 101 of the lateral fossa 120 and the lateral condyle, thereby providing a larger displacement amount for the articular surface of the medial condyle. When the articular surface of the medial condyle is displaced forward and backward, it can contact with different concave surfaces 101 of the medial fossa 110 to avoid stress concentration. The knee joint liner 100 of the embodiment of the present invention can provide a high contact area, simulate natural knee joint movement, retain more bone and reduce the incidence of joint instability, significantly improving the effect of knee replacement and patient satisfaction.

[0041] According to the anatomical feature of the human meniscus that the inner side is larger than the outer side, the contact surface of the concave cavity in the medial fossa 110 of the present invention is larger than the contact surface of the concave cavity in the lateral fossa 120, thereby providing a larger displacement for the articular surface of the medial condyle. The articular surface of the medial condyle is appropriately displaced so as to contact the concave surface 101 at different positions of the medial fossa 110.

[0042] Alternatively, if Figure 2 and Figure 3As shown, in the medial fossa 110, the elliptical minor axes of the outer peripheral contours of the plurality of concave surfaces 101 are of the same size. Thus, when the articular surface of the medial condyle displaces forward and backward and contacts different concave surfaces 101 of the medial fossa 110, the stability of the contact between the medial condyle and the medial fossa 110 can be ensured, so that the patient can forget about joint replacement, thereby improving the patient's satisfaction.

[0043] like Figure 4 and Figure 5 As shown, in the lateral fossa 120, the elliptical minor axes of the outer peripheral contours of the plurality of concave surfaces 101 are of the same size. Thus, when the articular surface of the lateral condyle displaces forward and backward and contacts different concave surfaces 101 of the lateral fossa 120, the stability of the contact between the lateral condyle and the lateral fossa 120 can be ensured, so that the patient can forget about joint replacement, thereby improving the patient's satisfaction.

[0044] In some embodiments, Figure 2 and Figure 3 As shown, in the medial fossa 110, there are at least three concave surfaces 101, and the ellipse centers of the three concave surfaces 101 are arranged at intervals along the front-back direction of the knee joint liner 100. For example, in the medial fossa 110, there may be three, four, five or six concave surfaces 101.

[0045] Preferably, in the medial fossa 110 , there are at least six concave surfaces 101 .

[0046] Specifically, Figure 2 and Figure 3 As shown, in the medial fossa 110, the concave surface 101 includes a first medial concave surface 1011, a second medial concave surface 1012, a third medial concave surface 1013, a fourth medial concave surface 1014 and a fifth medial concave surface 1015, the intersection of the median coronal plane of the knee joint liner 100 and the sagittal plane passing through the lowest point of the medial fossa 110 constitutes the ellipse center O1 of the first medial concave surface 1011, the ellipse center O2 of the second medial concave surface 1012 and the ellipse center O3 of the third medial concave surface 1013 are arranged on the front side of the ellipse center O1 of the first medial concave surface 1011, and the ellipse center O4 of the fourth medial concave surface 1014 and the ellipse center O5 of the fifth medial concave surface 1015 are arranged on the rear side of the ellipse center O1 of the first medial concave surface 1011.

[0047] In other words, the ellipse center O3 of the third inner concave surface 1013, the ellipse center O2 of the second inner concave surface 1012, the ellipse center O1 of the first inner concave surface 1011, the ellipse center O4 of the fourth inner concave surface 1014 and the ellipse center O5 of the fifth inner concave surface 1015 are arranged in sequence from front to back.

[0048] The inventors of the present application have discovered through experimental research that when the concave surfaces 101 in the medial fossa 110 are of the above-mentioned number and arrangement, the stability of the contact between the medial condyle and the medial fossa 110 can be ensured, and it is closer to the movement principle of the natural knee joint, which is conducive to enhancing patient satisfaction.

[0049] Alternatively, if Figure 4 and Figure 5 As shown, in the lateral fossa 120, there are at least two concave surfaces 101, and the two concave surfaces 101 are arranged at intervals along the front-back direction of the knee joint liner 100. For example, in the lateral fossa 120, there can be two, three, four, five or six concave surfaces 101.

[0050] Specifically, Figure 4 and Figure 5 As shown, in the lateral fossa 120, the concave surface 101 includes a first lateral concave surface 1016, a second lateral concave surface 1017 and a third lateral concave surface 1018, the intersection of the median coronal plane of the knee joint liner 100 and the sagittal plane passing through the lowest point of the lateral fossa 120 constitutes the ellipse center P1 of the first lateral concave surface 1016, the ellipse center P2 of the second lateral concave surface 1017 and the ellipse center P3 of the third lateral concave surface 1018 are respectively arranged on the front and rear sides of the ellipse center P1 of the first lateral concave surface 1016.

[0051] In other words, the ellipse center P2 of the second outer concave surface 1017, the ellipse center P1 of the first outer concave surface 1016, and the ellipse center P3 of the third outer concave surface 1018 are arranged in sequence from front to back.

[0052] The inventors of the present application have discovered through experimental research that when the concave surfaces 101 in the lateral fossa 120 are of the above-mentioned number and arrangement, the stability of the contact between the lateral condyle and the lateral fossa 120 can be ensured, and it is closer to the movement principle of the natural knee joint, which is conducive to enhancing patient satisfaction.

[0053] It is understandable that the knee joint liner 100 adopts the above structural arrangement to ensure that the contact area between the femoral condyle and the liner in the sagittal plane and the coronal plane is maximized. Specifically, the contact area between the medial condyle and the medial fossa 110 can reach more than 97%, and the contact area between the lateral condyle and the lateral fossa 120 is more than 89%. In addition, the above design method can reduce the wear of the polyethylene prosthesis, avoid point contact or stress concentration, thereby significantly enhancing the service life of the prosthesis, reducing the incidence of joint instability, and helping to improve the stability of the knee joint prosthesis during movement.

[0054] Alternatively, if Figure 3As shown, in the medial socket 110, the outer peripheral contour of the concave surface 101 has a dimension A1 along the left-right direction of the knee joint liner 100, wherein 20 mm ≤ A1 ≤ 40 mm. For example, A1 may be 20 mm, 25 mm, 30 mm, 35 mm, or 40 mm.

[0055] In the medial socket 110 , the outer peripheral contour of the concave surface 101 has a dimension B1 along the anterior-posterior direction of the knee joint liner 100 , wherein 38 mm ≤ B1 ≤ 52 mm. For example, B1 may be 38 mm, 42 mm, 45 mm, 48 mm, 50 mm, or 52 mm.

[0056] The inventors of the present application have discovered through experimental research that when the contour of the concave surface 101 in the medial fossa 110 adopts the above-mentioned parameter range, it can ensure that the contact area between the medial condyle and the medial fossa 110 is larger during movement, and the stability during movement is higher, which is closer to the movement principle of the natural knee joint and is conducive to enhancing patient satisfaction.

[0057] Alternatively, if Figure 5 As shown, in the lateral socket 120, the outer peripheral contour of the concave surface 101 along the left-right direction of the knee joint liner 100 has a dimension A2, wherein 18 mm ≤ A2 ≤ 38 mm. For example, A2 may be 18 mm, 20 mm, 25 mm, 30 mm, 35 mm, or 38 mm.

[0058] In the lateral socket 120, the outer peripheral contour of the concave surface 101 has a dimension B2 along the anterior-posterior direction of the knee joint liner 100, wherein 35 mm ≤ B2 ≤ 50 mm. For example, B2 may be 35 mm, 38 mm, 42 mm, 45 mm, 48 mm, or 50 mm.

[0059] The inventors of the present application have discovered through experimental research that when the contour of the concave surface 101 in the lateral fossa 120 adopts the above-mentioned parameter range, it can ensure that the contact between the lateral condyle and the lateral fossa 120 is more stable during movement, and the matching degree between the lateral condyle and the lateral fossa 120 is better, which is closer to the movement principle of the natural knee joint, and is conducive to enhancing patient satisfaction.

[0060] Alternatively, if Figure 1 As shown, the distance between the median sagittal plane of the knee joint liner 100 and the sagittal plane passing through the lowest point of the medial fossa 110 is L1, wherein 20 mm ≤ L1 ≤ 30 mm. For example, L1 may be 20 mm, 22 mm, 24 mm, 26 mm, 28 mm, or 30 mm.

[0061] like Figure 1As shown, the distance between the median sagittal plane of the knee joint liner 100 and the sagittal plane passing through the lowest point of the lateral fossa 120 is L2, wherein 20 mm ≤ L2 ≤ 30 mm. For example, L2 can be 20 mm, 22 mm, 24 mm, 26 mm, 28 mm, or 30 mm.

[0062] The inventors of the present application have discovered through experimental research that when the medial fossa 110 and the lateral fossa 120 of the knee liner 100 are arranged in the above manner, the wear of the knee liner 100 and the femoral prosthesis can be slowed down, and the probability of restricted joint movement is reduced, which is beneficial to improving the stability of the knee prosthesis during movement, and the patient satisfaction is high.

[0063] Alternatively, if Figure 3 As shown, in the medial fossa 110, the distances between the ellipse centers of each two adjacent concave surfaces 101 along the front-back direction of the knee joint pad 100 are equal. For example, the distance between the ellipse center O3 of the third medial concave surface 1013 and the ellipse center O2 of the second medial concave surface 1012 is equal to the distance between the ellipse center O1 of the first medial concave surface 1011 and the ellipse center O2 of the second medial concave surface 1012. The distance between the ellipse center O5 of the fifth medial concave surface 1015 and the ellipse center O4 of the fourth medial concave surface 1014 is equal to the distance between the ellipse center O1 of the first medial concave surface 1011 and the ellipse center O4 of the fourth medial concave surface 1014. In this way, the medial condyle can be more stably contacted with the medial fossa 110 during movement, and the matching degree between the medial condyle and the medial fossa 110 is better, which is closer to the movement principle of the natural knee joint, and is conducive to enhancing patient satisfaction.

[0064] Alternatively, if Figure 5 As shown, in the lateral fossa 120, the distances between the ellipse centers of each two adjacent concave surfaces 101 along the front-back direction of the knee joint pad 100 are equal. In other words, the distance between the ellipse center P2 of the second lateral concave surface 1017 and the ellipse center P1 of the first lateral concave surface 1016 is equal to the distance between the ellipse center P3 of the third lateral concave surface 1018 and the ellipse center P1 of the first lateral concave surface 1016. This can make the contact between the lateral condyle and the lateral fossa 120 more stable during movement, and the matching degree between the lateral condyle and the lateral fossa 120 is better, which is closer to the movement principle of the natural knee joint, and is conducive to enhancing patient satisfaction.

[0065] Alternatively, if Figure 3 As shown, in the medial fossa 110, the distance between the ellipse centers of two adjacent concave surfaces 101 along the front-back direction of the knee joint pad 100 is C1, wherein 1mm≤C1≤2mm. For example, C1 can be 1mm, 1.5mm, or 2mm.

[0066] like Figure 4As shown, in the lateral socket 120, the distance between the centers of the ellipses of two adjacent concave surfaces 101 along the front-back direction of the knee joint pad 100 is C2, wherein 2mm≤C2≤4mm. For example, C2 can be 2mm, 2.5mm, 3mm, or 4mm.

[0067] During normal human activities, flexion is accompanied by appropriate internal and external rotation. When the knee joint is in initial internal rotation, the articular surface of the lateral condyle initially contacts the first lateral concave surface 1016, and then the articular surface of the lateral condyle moves forward, and the articular surface of the lateral condyle gradually contacts the second lateral concave surface 1017, at which time the articular surface of the lateral condyle moves forward slowly by about 2-4 mm. At the same time, when the knee joint is in initial internal rotation, the articular surface of the medial condyle initially contacts the first medial concave surface 1011, and then the articular surface of the medial condyle moves backward, and the articular surface of the medial condyle gradually contacts the fourth medial concave surface 1014, at which time the articular surface of the medial condyle moves backward slowly by about 1 mm.

[0068] The movement of the above-mentioned femoral prosthesis can easily make patients forget about joint replacement, in order to realize the concept of quasi-medial axis. This structure is consistent with the kinematics of the human knee joint. The medial axis motion design imitates the movement characteristics of the natural knee joint, which not only improves the stability of the knee joint, but also enhances the patient's satisfaction.

[0069] A knee joint prosthesis according to another embodiment of the present invention comprises: a femoral prosthesis and a knee joint liner 100 . The femoral prosthesis comprises a medial condyle and a lateral condyle. The knee joint liner 100 is the knee joint liner 100 of the present invention. The medial condyle cooperates with a medial fossa 110 , and the lateral condyle cooperates with a lateral fossa 120 .

[0070] According to the knee prosthesis of the embodiment of the present invention, since the outer peripheral contour of the concave surface 101 is elliptical, and the elliptical centers of the multiple concave surfaces 101 are arranged at intervals along the anterior-posterior direction of the knee joint pad 100, when the knee joint is in different flexion angles, the femoral prosthesis can contact the concave surfaces 101 at different positions to simulate the movement of the natural knee joint. On the one hand, the contact area between the knee joint pad 100 and the femoral prosthesis is increased, and on the other hand, the probability of joint movement restriction can be reduced, which is beneficial to improving the stability of the knee prosthesis during movement, and the patient satisfaction is high.

[0071] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0072] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0073] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, 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 specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a 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 higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0075] In the present invention, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0076] Although the above embodiments have been shown and described, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. Changes, modifications, substitutions and variations of the above embodiments by those of ordinary skill in the art are all within the scope of protection of the present invention.

Claims

1. A knee joint pad, characterized in that: The knee pad comprises a medial fossa and a lateral fossa, wherein at least one of the medial fossa and the lateral fossa has a plurality of ellipsoidal concave surfaces, wherein in a projection plane orthogonal to the thickness direction of the knee joint pad, the outer peripheral contour of the concave surfaces is an ellipse, wherein the major axis of the ellipse extends along the front-to-back direction of the knee joint pad, and the minor axis of the ellipse extends along the left-to-right direction of the knee joint pad, and the ellipse centers of the plurality of concave surfaces are arranged at intervals along the front-to-back direction of the knee joint pad.

2. The knee joint pad according to claim 1, characterized in that In the medial fossa, the minor axes of the ellipses of the outer peripheral contours of the plurality of concave surfaces are the same in size; And / or, in the lateral fossa, the sizes of the minor axes of the ellipses of the outer peripheral contours of the plurality of concave surfaces are the same.

3. The knee joint pad according to claim 1, characterized in that The outer peripheral contour of the concave surface in the medial fossa is larger than the outer peripheral contour of the concave surface in the lateral fossa.

4. The knee joint pad according to claim 1, characterized in that In the medial fossa, there are at least three concave surfaces, and the ellipse centers of the three concave surfaces are arranged at intervals along the front-back direction of the knee joint pad; And / or, in the lateral socket, there are at least two concave surfaces, and the two concave surfaces are arranged at intervals along the front-back direction of the knee joint pad.

5. The knee joint pad according to claim 1, characterized in that In the medial fossa, the concave surface includes a first medial concave surface, a second medial concave surface, a third medial concave surface, a fourth medial concave surface and a fifth medial concave surface, the intersection of the median coronal plane of the knee joint liner and the sagittal plane passing through the lowest point of the medial fossa constitutes the ellipse center of the first medial concave surface, the ellipse centers of the second medial concave surface and the third medial concave surface are arranged in front of the ellipse center of the first medial concave surface, and the ellipse centers of the fourth medial concave surface and the fifth medial concave surface are arranged in back of the ellipse center of the first medial concave surface; And / or, in the lateral fossa, the concave surface includes a first lateral concave surface, a second lateral concave surface and a third lateral concave surface, the intersection of the median coronal plane of the knee joint pad and the sagittal plane passing through the lowest point of the lateral fossa constitutes the ellipse center of the first lateral concave surface, and the ellipse center of the second lateral concave surface and the ellipse center of the third lateral concave surface are respectively arranged on the front and rear sides of the ellipse center of the first lateral concave surface.

6. The knee joint pad according to claim 1, characterized in that In the medial fossa, the dimension of the outer peripheral contour of the concave surface along the left-right direction of the knee joint pad is A1, wherein 20 mm ≤ A1 ≤ 40 mm; and / or, in the medial fossa, the dimension of the outer peripheral contour of the concave surface along the anterior-posterior direction of the knee joint pad is B1, wherein 38 mm ≤ B1 ≤ 52 mm; and / or, in the lateral socket, the outer peripheral contour of the concave surface has a dimension A2 along the left-right direction of the knee joint pad, wherein 18 mm ≤ A2 ≤ 38 mm; And / or, in the lateral socket, a dimension of an outer peripheral contour of the concave surface along the anterior-posterior direction of the knee joint pad is B2, wherein 35 mm ≤ B2 ≤ 50 mm.

7. The knee joint pad according to claim 1, characterized in that The distance between the median sagittal plane of the knee joint pad and the sagittal plane passing through the lowest point of the medial fossa is L1, wherein 20 mm ≤ L1 ≤ 30 mm; And / or, a distance between a median sagittal plane of the knee joint pad and a sagittal plane passing through the lowest point of the lateral fossa is L2, wherein 20 mm ≤ L2 ≤ 30 mm.

8. The knee joint pad according to claim 1, characterized in that In the medial fossa, the distances between the centers of the ellipses of each of the two adjacent concave surfaces along the front-back direction of the knee joint pad are equal; And / or, in the lateral socket, the distances between the centers of the ellipses of each two adjacent concave surfaces along the front-back direction of the knee joint pad are equal.

9. The knee joint pad according to claim 1, characterized in that In the medial fossa, the distance between the centers of the ellipses of two adjacent concave surfaces along the anterior-posterior direction of the knee joint pad is C1, wherein 1 mm ≤ C1 ≤ 2 mm; And / or, in the lateral socket, the distance between the centers of the ellipses of two adjacent concave surfaces along the anterior-posterior direction of the knee joint pad is C2, wherein 2mm≤C2≤4mm.

10. A knee joint prosthesis, characterized in that: include: A femoral prosthesis, the femoral prosthesis comprising a medial condyle and a lateral condyle; A knee joint pad, wherein the knee joint pad is the knee joint pad according to any one of claims 1 to 9, wherein the medial condyle cooperates with the medial fossa, and the lateral condyle cooperates with the lateral fossa.

Images