Femoral condyle prosthesis, tibia prosthesis and knee joint prosthesis

Abstract

The invention discloses a femoral condyle prosthesis, a tibia prosthesis and a knee joint prosthesis, and belongs to the technical field of medical instruments.The size parameters of the femoral condyle prosthesis are set to meet a relational expression, so that a proper relative position relation is formed between a rear cam and a condyle joint surface, and in the process that the femoral condyle prosthesis does knee joint flexion motion, the knee joint flexion motion is achieved. The rear cam and the condylar joint surface have a proper relative movement track, so that the height of the rear cam relative to the lowest point of the condylar joint surface can be always kept within a reasonable height range. Therefore, the pressure of the rear cam on the stand column can be always kept at a low level, abrasion of the rear cam and the stand column caused by overlarge pressure between the rear cam and the stand column is avoided, meanwhile, the fatigue strength of the stand column can be effectively kept, and risks of stand column breakage and rear cam dislocation are reduced. And the motion trail of the rear cam relative to the condylar joint surface enables the rear cam to be in contact with the stand column during moderate flexion, so that unstable moderate flexion of the knee joint can be avoided.

Description

Technical Field

[0001] The present application belongs to the technical field of orthopedic surgical implants, and specifically relates to a femoral condyle prosthesis, a tibial prosthesis and a knee joint prosthesis. Background Art

[0002] Total Knee Replacement (TKR) is used to treat diseases or trauma of the knee joint. TKR usually uses a femoral condyle prosthesis to replace the distal femoral joint surface, a tibial prosthesis to replace the proximal tibial joint surface, and in some cases a patellar component to replace the patellar joint surface. There are two main types of prostheses used in the knee joint: one is a posterior cruciate ligament retaining prosthesis, which does not require the removal of the posterior cruciate ligament and bone tissue; the other is a posterior stabilized prosthesis, which requires the removal of the posterior cruciate ligament and bone tissue.

[0003] The femoral condyle prosthesis of the posterior-stabilized knee prosthesis has a posterior cam, and the tibial prosthesis has a column that can contact the posterior cam. The posterior cam and the column contact to increase the stability of the knee flexion process. The flexion angle of the knee prosthesis is generally 115°-130°, and the extreme flexion angle can reach 150° in some cases. For the current knee prosthesis structure, as the flexion angle increases, the contact point between the posterior cam of the femoral condyle prosthesis and the column of the tibial prosthesis continues to move upward. Under the action of the ligaments and muscles around the knee joint, the force and torque of the column continue to increase. The larger contact stress will increase the friction and wear between the posterior cam and the column, reduce the fatigue strength of the column, and increase the risk of dislocation and column fracture. Summary of the invention

[0004] Purpose of the invention: An embodiment of the present application provides a femoral condyle prosthesis, aiming to solve the technical problem that the contact point between the posterior cam of the current femoral condyle prosthesis structure and the column of the tibial prosthesis will continue to move upward with the increase of the flexion angle, increasing the risk of dislocation and causing column fracture; another purpose of the embodiment of the present application is to provide a tibial prosthesis; another purpose of the embodiment of the present application is to provide a knee joint prosthesis.

[0005] Technical solution: A femoral condyle prosthesis described in an embodiment of the present application includes:

[0006] A first condyle and a second condyle arranged along a first direction, an intercondylar notch defined between the first condyle and the second condyle, at least one of the first condyle and the second condyle having a connection surface and a condylar articular surface facing away from the connection surface, the connection surface being used to connect to a distal end surface of a femoral osteotomy;

[0007] A rear cam, the rear cam is disposed in the intercondylar notch and connected to at least one of the first condyle and the second condyle; at least one cross-section of the rear cam perpendicular to the first direction has a contour curve, and the distance between the point on the contour curve closest to the first reference plane AA' and the first reference plane AA' is h 1 ; the first reference plane AA' is parallel to the connection surface and tangent to the condylar joint surface at the tangent point O;

[0008] The distance between the point on the contour curve farthest from the second reference plane BB' and the second reference plane BB' is l 1 ; the second reference plane BB' passes through the tangent point O, is parallel to the first direction, and is perpendicular to the connection surface;

[0009] The maximum dimension of the femoral condyle prosthesis along the second direction is L AP , the second direction is perpendicular to the second reference plane BB';

[0010] Satisfy:

[0011] L AP = a*h 1 + b, and, L AP = c*l 1 - d;

[0012] Wherein, a, b, c, and d are all constants, 2.0 ≤ a ≤ 2.9, 5.5 ≤ b ≤ 11.5, 2.3 ≤ c ≤ 3.3, 10.5 ≤ d ≤ 16.

[0013] In some embodiments, at least a part of the contour curve is an arc line, and the radius of curvature of the arc line is r 1 , satisfy: 1mm ≤ r 1 ≤ 20mm.

[0014] In some embodiments, the contour curve includes multiple segments of the arc line, the multiple segments of the arc line are connected in sequence, and adjacent two segments of the arc line are tangent, and the radii of curvature of at least two adjacent segments of the arc line are different.

[0015] In some embodiments, the femoral condyle prosthesis can rotate relative to the tibial prosthesis, and during the rotation, the condylar joint surface contacts the supporting joint surface of the tibial prosthesis;

[0016] The condylar joint surface has a condylar curve and a first contact point P and a second contact point Q located on the condylar curve in a reference plane perpendicular to the first direction;

[0017] When the femoral condyle prosthesis rotates by a first angle relative to the tibial prosthesis, the first contact point P contacts the supporting joint surface, and the posterior cam initially contacts the column of the tibial prosthesis;

[0018] When the femoral condyle prosthesis rotates by a second angle relative to the tibial prosthesis, the second contact point Q contacts the supporting joint surface, and the second angle is greater than the first angle;

[0019] The portion of the condyle curve between the first contact point P and the second contact point Q is a first curve segment, at least part of the first curve segment is an arc, and the radius of curvature of the arc of the first curve segment is R 1 , satisfying:

[0020] Rmin ≤ R 1 ≤ Rmax, and Rmin = e * L AP - f, Rmax = e' * L AP - f';

[0021] wherein, e, f, e', f' are all constants, 0.22 ≤ e ≤ 0.24, -2.5 ≤ f ≤ 3.5, 0.41 ≤ e' ≤ 0.45, 2.6 ≤ f' ≤ 8.6.

[0022] In some embodiments, it also satisfies: 6.4 mm ≤ R 1 ≤ 35.6 mm.

[0023] In some embodiments, the first curve segment includes multiple connected arcs, and from the first contact point P to the second contact point Q, the radius of curvature of the multiple arcs gradually decreases or remains the same.

[0024] In some embodiments, the first angle is 60 - 75°.

[0025] In some embodiments, the second angle is the maximum angle by which the femoral condyle prosthesis can rotate relative to the tibial prosthesis.

[0026] In some embodiments, it satisfies: 45 mm ≤ L AP ≤ 85 mm, 11.6 mm ≤ h 1 ≤ 39.8 mm, 16.8 mm ≤ l 1 ≤ 43.9 mm for at least one of them.

[0027] In some embodiments, it also satisfies: 48.5 mm ≤ L AP ≤ 75.3 mm, 12.8 mm ≤ h 1 ≤ 34.9 mm, 17.9 mm ≤ l 1 ≤ 39.7 mm for at least one of them.

[0028] In some embodiments, the constant a satisfies: 2.2 ≤ a ≤ 2.6, and / or, the constant c satisfies: 2.6 ≤ c ≤ 3.0.

[0029] In some embodiments, both the first condyle and the second condyle have the connecting surface and the condylar articular surface;

[0030] The posterior cam is respectively connected to the first condyle and the second condyle.

[0031] In some embodiments, all cross-sections of the posterior cam perpendicular to the first direction have the profile curve.

[0032] Correspondingly, a tibial prosthesis according to an embodiment of the present application includes:

[0033] A platform, the platform includes a supporting articular surface and a first end surface and a second end surface facing away from each other along a third direction, the supporting articular surface is located between the first end surface and the second end surface, and the supporting articular surface is used for movably connecting with the condylar articular surface of the femoral condyle prosthesis;

[0034] A column, connected to the platform and protruding along a fourth direction from the supporting articular surface, the third direction is perpendicular to the fourth direction;

[0035] The column has a cam contact surface, the cam contact surface faces away from the first end surface, and the cam contact surface is used for contacting with the posterior cam of the femoral condyle prosthesis;

[0036] The maximum dimension of the platform along the third direction is L AP’ , and the maximum dimension along the third direction between the cam contact surface and the second end surface is l 2 , satisfying: 0.3 ≤ l 2 / L AP’ ≤ 0.42.

[0037] In some embodiments, the cam contact surface has a first column curve, a second column curve, and a third column curve connected in the same reference plane, the first column curve, the second column curve, and the third column curve are arranged in sequence along the fourth direction, and the second column curve is tangent to the first column curve and the third column curve respectively and has different curvature radii;

[0038] Wherein, the reference plane is parallel to the third direction and the fourth direction.

[0039] In some embodiments, the first column curve has a curvature center O', and the maximum dimension along the third direction between the curvature center O' and the second end surface is l 3 , satisfying:

[0040] l 3 = i * l 2 -j;

[0041] Wherein, both i and j are constants, and 0.9 ≤ i ≤ 1, 3.8 ≤ j ≤ 9.8.

[0042] In some embodiments, the radius of curvature of the first column curve is r 2 , satisfying: 15 mm ≤ r 2 ≤ 37 mm; the radius of curvature of the second column curve is r 3 , satisfying: 3 mm ≤ r 3 ≤ 17 mm.

[0043] In some embodiments, the maximum dimension along the third direction of the points forming the second column curve and the points forming the third column curve is l 4 , satisfying: l 4 ≥ 0.5 mm.

[0044] Correspondingly, a knee joint prosthesis according to an embodiment of the present application includes:

[0045] A femoral condyle prosthesis, which includes a first condyle, a second condyle and a posterior cam. The first condyle and the second condyle are arranged along a first direction, and an intercondylar notch is defined between the first condyle and the second condyle. At least one of the first condyle and the second condyle has a condylar joint surface; the posterior cam is disposed in the intercondylar notch and is connected to at least one of the first condyle and the second condyle;

[0046] A tibial prosthesis, which includes a platform and a column. The platform includes a bearing joint surface, and the column is connected to the platform and protrudes along a fourth direction relative to the bearing joint surface;

[0047] The femoral condyle prosthesis can rotate relative to the tibial prosthesis. During the rotation, the condylar joint surface is in contact with the bearing joint surface; the maximum dimension of the tibial prosthesis along the third direction is L AP’ , and the maximum dimension of the femoral condyle prosthesis along the third direction is L AP , and the third direction is perpendicular to the first direction and the fourth direction;

[0048] The condylar joint surface has a condylar curve and a first contact point P and a second contact point Q located on the condylar curve in a reference plane perpendicular to the first direction. The bearing joint surface has a bearing curve in the same reference plane, and the bearing curve is opposite to the condylar curve;

[0049] When the femoral condyle prosthesis rotates by a first angle relative to the tibial prosthesis, the first contact point P contacts the support curve, and the posterior cam initially contacts the column; when the femoral condyle prosthesis rotates by a second angle relative to the tibial prosthesis, the second contact point Q contacts the support curve, and the second angle is greater than the first angle.

[0050] The portion of the condyle curve between the first contact point P and the second contact point Q is a first curve segment, at least part of the first curve segment is an arc, and the radius of curvature of the arc of the first curve segment is R 1 ; The support curve includes a second curve segment opposite to the first curve segment, at least part of the second curve segment is an arc, and the radius of curvature of the arc of the second curve segment is R 2 , satisfying: Rmin ≤ R 1 ≤ Rmax < R 2 ;

[0051] Wherein, Rmin = e * L AP - f, Rmax = e' * L AP - f', R 2 = g * L AP’ - m;

[0052] e, f, e', f', g, m are all constants, 0.22 ≤ e ≤ 0.24, -2.5 ≤ f ≤ 3.5, 0.41 ≤ e' ≤ 0.45, 2.6 ≤ f' ≤ 8.6, 1.72 ≤ g ≤ 1.74, 8 ≤ m ≤ 13.

[0053] In some embodiments, it satisfies: 45mm ≤ L AP ≤ 85mm, 36mm ≤ L AP’ ≤ 57mm.

[0054] In some embodiments, it satisfies: 2.4 ≤ R 2 / R 1 ≤ 6.5.

[0055] In some embodiments, it also satisfies: 2.9 ≤ R 2 / R 1 ≤ 4.8.

[0056] In some embodiments, the second curve segment includes a plurality of connected arcs, and the radius of curvature of the plurality of arcs gradually changes or remains the same.

[0057] In some embodiments, the column has a cam contact surface for contacting the posterior cam;

[0058] The rear cam has a contour curve in a reference plane perpendicular to the first direction, at least part of the contour curve being an arc line. The cam contact surface has a first upright curve, a second upright curve, and a third upright curve connected in the same reference plane. The first upright curve, the second upright curve, and the third upright curve are arranged in sequence along the fourth direction. The second upright curve is tangent to the first upright curve and the third upright curve respectively and has different radii of curvature;

[0059] wherein, the radius of curvature of the arc line is r 1 , and the radius of curvature of the first upright curve is r 2 , satisfying: r 2 > r 1 .

[0060] In some embodiments, it also satisfies: 1.5 ≤ r 2 / r 1 ≤ 4.5.

[0061] Correspondingly, a knee joint prosthesis provided by an embodiment of the present application includes:

[0062] The femoral condyle prosthesis as described above; and / or, the tibial prosthesis as described above.

[0063] Beneficial effects: In the embodiment of the present application, by setting the L AP , h 1 , l 1 dimension parameters of the femoral condyle prosthesis to satisfy the above relational expressions, a suitable relative positional relationship is obtained between its rear cam and the condylar joint surface. During the knee flexion movement of the femoral condyle prosthesis, a suitable relative movement trajectory exists between the rear cam and the condylar joint surface, such that the height of the rear cam relative to the lowest point of the condylar joint surface can always be maintained within a reasonable height range. Thus, on the one hand, during the process of the femoral condyle prosthesis cooperating with the matching tibial prosthesis to rotate to flex the knee joint, the contact point of the rear cam of the femoral condyle prosthesis on the upright of the tibial prosthesis can always be maintained at a lower position, and thus the pressure of the rear cam on the upright can always be maintained at a lower level, avoiding wear of the rear cam and the upright due to excessive pressure between the two, and at the same time effectively maintaining the fatigue strength of the upright and reducing the risk of upright fracture and rear cam dislocation; on the other hand, during the knee flexion process, the movement trajectory of the rear cam relative to the condylar joint surface enables it to contact the upright at medium flexion, such that the femoral condyle prosthesis can be restricted by the upright to avoid forward movement relative to the tibial prosthesis, helping to avoid the occurrence of knee joint instability during medium flexion and improving stability.

[0064] In the embodiment of the present application, by setting the L AP’ , l 2The dimensional parameters satisfy the above relationship, such that the cam contact surface of the column is located at a proper position on the platform. Thus, on one hand, during the process of the matched femoral condyle prosthesis rotating relative to the tibial prosthesis to flex the knee joint, at a relatively small rotation angle, the posterior cam of the femoral condyle prosthesis can contact the column, and maintain the contact during moderate flexion and subsequent flexion, avoiding the anterior movement of the femoral condyle prosthesis relative to the tibial prosthesis and preventing instability during moderate flexion; on the other hand, it can help control the contact point of the posterior cam of the femoral condyle prosthesis on the column to remain at a lower position, reduce the force and moment on the column, enhance the fatigue strength of the column, and reduce the risks of column fracture and posterior cam dislocation.

[0065] In the embodiment of the present application, by setting in the same reference plane, the circular arc curvature radius R of the first curve segment of the femoral condyle prosthesis 1 and the circular arc curvature radius R of the second curve segment of the tibial prosthesis 2 satisfy the above relationship, such that during the flexion of the knee joint prosthesis, when the femoral condyle prosthesis rotates relative to the tibial prosthesis until the posterior cam contacts the column and then continues to rotate, since the supporting joint surface corresponding to the second curve segment has a larger curvature radius, it will not cause interference in the rotation space of the condylar joint surface corresponding to the first curve segment, and can avoid lifting the rotating femoral condyle prosthesis. Thus, it is beneficial to control the contact point of the posterior cam on the column to remain at a lower position, and further enable the pressure of the posterior cam on the column to always remain at a lower level, avoiding wear of the posterior cam and the column due to excessive pressure between the two, and at the same time, effectively maintaining the fatigue strength of the column and reducing the risks of column fracture and posterior cam dislocation. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following-described drawings are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0067] Figure 1 is an exploded structural schematic diagram of parts of a knee joint prosthesis provided by an embodiment of the present application;

[0068] Figure 2 is a three-dimensional structural schematic diagram of a femoral condyle prosthesis provided by an embodiment of the present application;

[0069] Figure 3 is a side view structural schematic diagram of a femoral condyle prosthesis along a first direction provided by an embodiment of the present application;

[0070] Figure 4 Viewed along the first directionFigure 3 Schematic structural diagram of the femoral condyle prosthesis connected to the femur;

[0071] Figure 5 is Figure 2 Schematic cross-sectional structural diagram of the femoral condyle prosthesis perpendicular to the first direction;

[0072] Figure 6 is Figure 5 Schematic diagram of the cross-sectional structure in [[ ]] rotated to another angle;

[0073] Figure 7 is Figure 5 Enlarged partial structural diagram at the posterior cam of the femoral condyle prosthesis in [[ ]];

[0074] Figure 8 Cross-sectional structural diagram of the femoral condyle prosthesis of the embodiment of the present application rotated to the first angle relative to the tibial prosthesis;

[0075] Figure 9 Exploded structural diagram of the parts of the tibial prosthesis provided by the embodiment of the present application;

[0076] Figure 10 Cross-sectional structural diagram of the platform and the column of the tibial prosthesis of the embodiment of the present application;

[0077] Figure 11 Cross-sectional structural diagram of the platform and the column of the tibial prosthesis of the embodiment of the present application;

[0078] Figure 12 Partial cross-sectional structural diagram of the knee joint prosthesis in the un-flexed state of some embodiments of the present application;

[0079] Figure 13 Partial cross-sectional structural diagram of the knee joint prosthesis in the first flexed state of some embodiments of the present application;

[0080] Figure 14 Partial cross-sectional structural diagram of the knee joint prosthesis in the second flexed state of some embodiments of the present application;

[0081] Figure 15 Partial cross-sectional structural diagram of the knee joint prosthesis in the third flexed state of some embodiments of the present application;

[0082] Figure 16 Partial cross-sectional structural diagram of the knee joint prosthesis in the fourth flexed state of some embodiments of the present application;

[0083] Figure 17 Partial cross-sectional structural diagram of the knee joint prosthesis in the fifth flexed state of some embodiments of the present application;

[0084] Figure 18Schematic diagram of the partial cross-section structure of the knee joint prosthesis in the sixth flexion state of some embodiments of the present application;

[0085] Figure 19 Schematic diagram of the partial cross-section structure of the knee joint prosthesis in the seventh flexion state of some embodiments of the present application;

[0086] Figure 20 Schematic diagram when the contact point between the posterior cam and the column is at the highest position;

[0087] Reference numerals: 100 - femoral condyle prosthesis; 110a - first condyle; 110b - second condyle; 111 - connecting surface; 112 - condylar articular surface; 1121 - condylar curve; 1122 - first curve segment; 113 - intercondylar notch; 120 - posterior cam; 121 - contour curve; 1211 - circular arc line; 200 - tibial prosthesis; 210 - platform; 211 - supporting articular surface; 2111 - supporting curve; 2112 - second curve segment; 212 - first end face; 213 - second end face; 220 - column; 221 - cam contact surface; 2211 - first column curve; 2212 - second column curve; 2213 - third column curve; 230 - tibial tray; 300 - femur; 310 - distal osteotomy end face. Detailed implementation manners

[0088] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0089] In the description of the present application, it should be understood that the term "distal end" refers to the end far from the head in anatomy, and the term "proximal end" refers to the end close to the head in anatomy. Terms such as "upper", "lower", "inner", "outer", "front", "rear", etc., which represent anatomical references, have well-known meanings in the field of bone research and orthopedics. The use of such anatomical reference terms in the specification and claims is intended to be consistent with their well-known meanings, unless otherwise specified. In the description of the present application, the meaning of "a plurality" is two or more, and at least one means one, two or more, unless otherwise clearly and specifically defined.

[0090] It should also be noted that in the drawings of the embodiments of the present application, arrows marked with Z, X, X', Y', and Y respectively represent the first direction Z, the second direction X, the third direction X', the fourth direction Y', and the fifth direction Y. The description of the present application introduces the first direction Z, the second direction X, the third direction X', the fourth direction Y', and the fifth direction Y to more clearly describe the structures and relative positional relationships of the components in the femoral condyle prosthesis 100, the tibial prosthesis 200, and the knee joint prosthesis.

[0091] In the related art, as the knee joint flexes, the posterior cam of the femoral condyle prosthesis contacts the post of the tibial prosthesis, and as the flexion angle increases, the contact point continuously moves upward, the force and moment on the post continuously increase, inevitably reducing the fatigue strength of the post and increasing the risk of posterior cam dislocation and post fracture. In addition, when the traditional knee joint is in moderate flexion, there is a situation of moderate flexion instability, that is, the femoral condyle prosthesis slides forward relative to the tibial prosthesis, which will cause wear problems of the knee joint prosthesis and reduce the service life of the knee joint prosthesis.

[0092] In view of this, please refer to Figure 1 , the embodiments of the present application provide a femoral condyle prosthesis 100, a tibial prosthesis 200, and a knee joint prosthesis to overcome at least one of the above technical problems.

[0093] The femoral condyle prosthesis 100 provided by the embodiments of the present application is used to be fixed to the distal end of the patient's femur 300 to replace the distal joint surface of the femur 300. The femoral condyle prosthesis 100 can be made of materials such as cobalt-chromium-molybdenum metal, titanium-based metal, ceramic, and bioengineering materials.

[0094] Please refer to Figures 2 to 5 together. The femoral condyle prosthesis 100 of the embodiments of the present application can be a posterior-stabilized femoral condyle prosthesis, which includes a first condyle 110a, a second condyle 110b, and a posterior cam 120.

[0095] The first condyle 110a and the second condyle 110b can respectively correspond to the medial condyle and the lateral condyle of the femur 300. The first condyle 110a and the second condyle 110b are arranged along the first direction Z, and an intercondylar notch 113 is defined between the two. It should be noted that the first direction Z refers to the arrangement direction of the first condyle 110a and the second condyle 110b. According to the actual state of the femoral condyle prosthesis 100 in space, the first direction Z can be any direction in space; when the femoral condyle prosthesis 100 is installed in the human body, the first direction Z is the direction from the inside to the outside or from the outside to the inside of the knee joint. Generally speaking, the first direction Z is perpendicular to the anatomical sagittal plane of the human body.

[0096] Wherein, at least one of the first condyle 110a and the second condyle 110b has a connecting surface 111 and a condylar articular surface 112 facing away from the connecting surface 111, and the connecting surface 111 is used to connect the osteotomy distal end surface 310 of the femur 300. Please refer specifically to Figure 4 , in a knee joint replacement surgery, the original articular surface of the femur 300 will be resected to form a cut surface, and the osteotomy distal end surface 310 is the most distal surface in the cut surface of the femur 300. Generally speaking, the osteotomy distal end surface 310 is parallel to the horizontal plane (cross-section) in anatomy. During the surgery, the doctor fits the connecting surface 111 with the osteotomy distal end surface 310 to realize the connection between the femoral condyle prosthesis 100 and the femur 300. The condylar articular surface 112 faces away from the connecting surface 111 and is used to replace the original articular surface of the femur 300. Preferably, both the first condyle 110a and the second condyle 110b have a connecting surface 111 and a condylar articular surface 112.

[0097] The posterior cam 120 is disposed in the intercondylar notch 113 and is connected to at least one of the first condyle 110a and the second condyle 110b. During the flexion of the knee joint, the femoral condyle prosthesis 100 rotates and slides relative to the tibial prosthesis 200. The posterior cam 120 is used to contact the column 220 of the tibial prosthesis 200 in a moderately flexed state of the knee joint to abut against the column 220, so as to prevent the femoral condyle prosthesis 100 from continuing to slide forward relative to the tibial prosthesis 200 and ensure the stability of the knee joint flexion. Wherein, the front corresponds to Figure 2 the reverse direction of the second direction X indicated by the X arrow in

[0098] Please also refer to Figure 3 and Figure 5, for the convenience of clearly describing the femoral condyle prosthesis 100 of the embodiments of the present application, the first reference plane AA' and the second reference plane BB' are introduced here. It should be noted that in the actual femoral condyle prosthesis 100 product, the first reference plane AA' and the second reference plane BB' are not physical planes that can be directly observed, but virtual planes that can be fitted on the femoral condyle prosthesis 100 through their specific definitions. Specifically, the first reference plane AA' is parallel to the connection surface 111 and tangent to the condylar joint surface 112 at the tangent point O. Geometrically, among all the planes parallel to the connection surface 111, the plane that is tangent to the condylar joint surface 112 can be found, which is the first reference plane AA', and the tangent position is the tangent point O. After the femoral condyle prosthesis 100 is installed in the human body and the knee joint is not flexed, the tangent point O is located at the distal end of the femoral condyle prosthesis 100. The second reference plane BB' passes through the tangent point O, is parallel to the first direction Z, and is perpendicular to the connection surface 111. Thus, geometrically, among all the planes passing through the tangent point O and perpendicular to the connection surface 111, the plane that is parallel to the first direction Z can be found, which is the second reference plane BB'.

[0099] Please refer to Figure 6 together. Since the first reference plane AA' and the second reference plane BB' satisfy the above limiting conditions, their positions relative to the femoral condyle prosthesis 100 are determined. As the femoral condyle prosthesis 100 rotates and moves, the first reference plane AA' and the second reference plane BB' also rotate and move together and always maintain their relationship with the femoral condyle prosthesis 100.

[0100] Please refer to again Figure 5 , among all the cross-sections of the posterior cam 120 perpendicular to the first direction Z, at least one cross-section has a contour curve 121. Among all the points that form the contour curve 121, the distance from the point closest to the first reference plane AA' to the first reference plane AA' is h 1 ; among all the points that form the contour curve 121, the distance from the point farthest from the second reference plane BB' to the second reference plane BB' is l 1 . The maximum dimension of the femoral condyle prosthesis 100 along the second direction X is L AP , and the second direction X is perpendicular to the second reference plane BB'.

[0101] The femoral condyle prosthesis 100 of the embodiments of the present application satisfies:

[0102] L AP = a * h 1 + b, and, L AP = c * l 1 - d;

[0103] Among them, a, b, c, and d are all constants, where 2.0 ≤ a ≤ 2.9, 5.5 ≤ b ≤ 11.5, 2.3 ≤ c ≤ 3.3, and 10.5 ≤ d ≤ 16.

[0104] In practical applications, femoral condyle prostheses 100 of different sizes and models are selected according to the needs of different patients, so that the specific size of L can be determined. AP Based on the specific size of L AP and the above relationships, the required h 1 and l 1 can be obtained respectively, and then the shape and size of the femoral condyle prosthesis 100 that meet the requirements of this application can be determined. Of course, h 1 and l 1 can also be set first, and then based on their specific sizes and the above relationships, the size of L AP that meets the requirements can be obtained, and then the shape and size of the femoral condyle prosthesis 100 that meet the requirements of this application can also be determined.

[0105] The constants a, b, c, and d only need to satisfy the above ranges. For example, the constant a can be any value among 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9 or the range value between any two values. Preferably, the constant a satisfies: 2.2 ≤ a ≤ 2.6. Within this range, the h AP obtained through the specific size of L 1 and the above relationships is more accurate; and when the specific size of h 1 is determined first, c in the above relationship is controlled within a smaller range of 2.6 ≤ c ≤ 3.0, and the L 1 obtained through h AP is also more accurate. As a further preference, a can be 2.37. For example, the constant b can be any value among 5.5, 6.5, 7.5, 8.5, 9.5, 10.5, 11.5 or the range value between any two values. Preferably, b can be 9.5. For example, the constant c can be any value among 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3 or the range value between any two values. Preferably, the constant c satisfies: 2.6 ≤ c ≤ 3.0. Within this range, the l AP obtained through the specific size of L 1 and the above relationships is more accurate; and when the specific size of l 1 is determined first, c in the above relationship is controlled within a smaller range of 2.6 ≤ c ≤ 3.0, and the L 1 obtained through l APIt is also more accurate. As a further preference, c can be 2.8. For example, the constant d can be any value among 10.5, 12.5, 13.0, 13.5, 14, 16 or the range value between any two values. As a preference, d can be 13.46.

[0106] For the actual femoral condyle prosthesis 100 product, L AP can be directly measured by a measuring tool. h 1 and l 1 can be modeled one-to-one for the product through three-dimensional scanning, CAD modeling, object reconstruction, 3D printing, etc. Then, the first reference plane AA' and the second reference plane BB' are fitted based on the model geometrically. Then, h 1 and l 1 are obtained respectively. Or directly cut the cross-section of the posterior cam 120 on the actual product. After fixing the product, the corresponding first reference plane AA' and the second reference plane BB' of the product are fitted in space, and the values of the contour curve 121 of the cross-section and the corresponding dimensions between the first reference plane AA' and the second reference plane BB' are directly measured.

[0107] It can be understood that the L AP 、h 1 、l 1 dimension parameters of the femoral condyle prosthesis 100 satisfy the above relational expressions. The dimension parameter relationship defines the structure and dimensions of the femoral condyle prosthesis 100, and also indirectly defines the relative position relationship between the posterior cam 120 and the condylar joint surface 112. Please also combine with Figures 12 to 15, during the process of the femoral condyle prosthesis 100 performing knee flexion movement, the relative movement trajectory of the posterior cam 120 and the condylar joint surface 112 is also limited by the above-mentioned dimensional parameter relationship. As the rotation angle of the femoral condyle prosthesis 100 increases, the movement trajectory of the posterior cam 120 is mainly downward and forward (downward is the opposite direction of the Y' arrow in the figure, and forward is the opposite direction of the X' arrow in the figure, which also respectively correspond to the lower and front directions of the human body), so that the height of the posterior cam 120 relative to the lowest point of the condylar joint surface 112 can always be maintained within a reasonable height range and will not be too high. Thus, during the process of the femoral condyle prosthesis 100 cooperating with the matching (structurally and dimensionally) tibial prosthesis 200 to rotate to flex the knee joint, the contact point of the posterior cam 120 of the femoral condyle prosthesis 100 on the column 220 of the tibial prosthesis 200 can always be maintained at a lower position. Furthermore, the pressure of the posterior cam 120 on the column 220 can always be maintained at a lower level, avoiding wear of the posterior cam 120 and the column 220 due to excessive pressure between the two. At the same time, it can also effectively control the torque of the column 220 from being too large, maintain the fatigue strength of the column 220, reduce the risk of fracture of the column 220 and dislocation of the posterior cam 120, and ensure the service life of the femoral condyle prosthesis 100 and the corresponding knee joint prosthesis. On the other hand, during the knee flexion process, the movement trajectory of the posterior cam 120 relative to the condylar joint surface 112 enables it to contact the column 220 at a relatively small medium flexion angle, so that the femoral condyle prosthesis 100 can be restricted by the column 220 to avoid moving forward relative to the tibial prosthesis 200, which helps to avoid the occurrence of knee joint medium flexion instability and improve stability.

[0108] It can be understood that the contour curve 121 is actually a part of the cam surface of the posterior cam 120. The posterior cam 120 contacts the column 220 of the tibial prosthesis 200. Correspondingly, the contour curve 121 will contact the column 220. Since the femoral condyle prosthesis 100 needs to rotate relative to the tibial prosthesis 200 to achieve knee flexion, generally speaking, the contour curves 121 of the condylar joint surface 112 and the posterior cam 120 are at least partially arc-shaped so as not to affect their relative rotation. That is to say, in some embodiments, the contour curve 121 is correspondingly located at the position of the posterior cam 120 for contacting the column 220 of the tibial prosthesis 200.

[0109] Preferably, in some embodiments, all cross-sections of the rear cam 120 perpendicular to the first direction Z have a contour curve 121. That is to say, the contour curves 121 of all cross-sections of the rear cam 120 perpendicular to the first direction Z all conform to the above-mentioned dimensional relationship formula. Thus, for different tibial prostheses 200, any position of the rear cam 120 contacts the column 220 of the tibial prosthesis 200, and the position of the contact point between the two can always be controlled, further improving the adaptability to the tibial prosthesis 200 and enabling it to adapt to more tibial prostheses 200.

[0110] Please refer to again Figure 5 and Figure 6 , in some embodiments, at least part of the contour curve 121 is an arc line 1211. Among them, the arc line 1211 is a curve with a determined radian, which has a degree of curvature and a curvature. The radius of curvature of the arc line 1211 is r 1 , satisfying: 1 mm ≤ r 1 ≤ 20 mm. For example, r 1 can be any value among 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm or a range value between any two values. By controlling the radius of curvature r 1 of the arc line 1211 within the above range, the position where the rear cam 120 contacts the column 220 has an appropriate curvature, which is beneficial to controlling the position of the contact point between the two.

[0111] For the actual femoral condyle prosthesis 100 product, r 1 can be modeled one-to-one for the product through three-dimensional scanning, CAD modeling, object reconstruction, 3D printing, etc., and then the specific value of r 1 is determined geometrically in the model.

[0112] Furthermore, please refer to Figure 7 , in some embodiments, the contour curve 121 includes multiple arc lines 1211. The multiple arc lines 1211 are connected in sequence, and adjacent two arc lines 1211 are tangent to each other, and the radii of curvature of at least two adjacent arc lines 1211 are different. As the knee joint flexion angle is different, the radius of curvature also changes dynamically, which can further accurately control the contact point between the rear cam 120 and the column 220.

[0113] In practical applications, the femoral condyle prosthesis 100 can rotate relative to the tibial prosthesis 200. During the rotation process, the condylar joint surface 112 contacts the supporting joint surface 211 of the tibial prosthesis 200, thereby simulating the flexion movement of the knee joint and replacing the original knee joint of the human body. Please refer to Figure 8In some embodiments, the condylar articular surface 112 has a condylar curve 1121 and a first contact point P and a second contact point Q located on the condylar curve 1121 in a reference plane perpendicular to the first direction Z. The reference plane is a virtual plane, which is introduced to clearly and briefly describe the relevant structure of the femoral condylar prosthesis 100. The reference plane is perpendicular to the first direction Z, and when the femoral condylar prosthesis 100 is installed in a human body, the reference plane is parallel to the sagittal plane of the human body in anatomy. It can be seen that there are actually countless planes perpendicular to the first direction Z. The femoral condylar prosthesis 100 is cut through any plane perpendicular to the first direction Z and intersecting with the condylar articular surface 112. On the cross section, the edge contour line corresponding to the condylar articular surface 112 is the condylar curve 1121, and the first contact point P and the second contact point Q are two points on the condylar curve 1121.

[0114] Please combine Figure 14 , when the femoral condyle prosthesis 100 rotates a first angle relative to the tibial prosthesis 200, the first contact point P contacts the support joint surface 211, and the posterior cam 120 initially contacts the column 220 of the tibial prosthesis 200. That is, during the flexion of the knee joint, at the moment when the posterior cam 120 of the femoral condyle prosthesis 100 contacts the column 220 of the tibial prosthesis 200, the first contact point P contacts the support joint surface 211, and the flexion angle of the knee joint is the first angle. When the femoral condyle prosthesis 100 rotates a second angle relative to the tibial prosthesis 200, the second contact point Q contacts the support joint surface 211, and the second angle is greater than the first angle. That is, during the continued flexion of the knee joint, the second contact point Q can contact the support joint surface 211, and the second contact point Q is a point of the femoral condyle prosthesis 100 that is more posterior (relative to the human body position) than the first contact point P.

[0115] The portion of the condylar curve 1121 between the first contact point P and the second contact point Q is a first curve segment 1122. At least a portion of the first curve segment 1122 is a circular arc, and the radius of curvature of the circular arc of the first curve segment 1122 is R. 1 ,satisfy:

[0116] Rmin≤R 1 ≤Rmax, and Rmin=e*L AP -f, Rmax = e'*L AP -f';

[0117] Among them, e, f, e', f' are all constants, 0.22≤e≤0.24, -2.5≤f≤3.5, 0.41≤e'≤0.45, 2.6≤f'≤8.6.

[0118] That is, e*L AP -f≤R 1 ≤e'*L AP-f'. In practical applications, femoral condyle prostheses 100 of different sizes and models are selected according to the needs of different patients, so that L AP can be determined. Based on the specific size of L AP and the above relationship, R 1 can be controlled. By controlling R 1 within the above range, the movement trajectory of the condylar joint surface 112 during knee flexion can be further controlled, especially the movement trajectory of the condylar joint surface 112 after the posterior cam 120 initially contacts the column 220 of the tibial prosthesis 200, thereby further optimizing the relative movement trajectory between the posterior cam 120 and the condylar joint surface 112, reducing the height of the posterior cam 120 relative to the lowest point of the condylar joint surface 112, and facilitating further reduction of the contact point position between the posterior cam 120 and the column 220 of the tibial prosthesis 200.

[0119] The constants e, f, e', and f' only need to satisfy the above range. For example, the constant e can be any value among 0.22, 0.23, 0.24 or the range value between any two values. Preferably, e can be 0.23. For example, the constant f can be any value among -2.5, -1.5, -0.5, 0.5, 1.5, 2.5, 3.5 or the range value between any two values. Preferably, f can be 0.5. For example, the constant e' can be any value among 0.41, 0.42, 0.43, 0.44, 0.45 or the range value between any two values. Preferably, the constant e' can be 0.43. For example, the constant f' can be any value among 2.6, 3.6, 4.6, 5.6, 6.6, 7.6, 8.6 or the range value between any two values. Preferably, f' can be 6.6.

[0120] Specifically, in some embodiments, the femoral condyle prosthesis further satisfies: 6.4 mm ≤ R 1 ≤ 35.6 mm. R 1 can be any value among 6.4 mm, 7 mm, 8 mm, 9 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 31 mm, 32 mm, 33 mm, 34 mm, 35 mm, 35.6 mm or the range value between any two values.

[0121] For the actual femoral condyle prosthesis 100 product, R 1 can be modeled one-to-one for the product through three-dimensional scanning, CAD modeling, object reconstruction, 3D printing, etc., and then the specific value of R 1 can be determined geometrically in the model.

[0122] Further, in some embodiments, the first curve segment 1122 includes a plurality of connected circular arcs. From the first contact point P to the second contact point Q, the radius of curvature of the plurality of circular arcs gradually decreases or remains the same. That is to say, the first curve segment 1122 can be a gradually changing curve, that is, the first curve segment 1122 is completely composed of a plurality of circular arcs, and the radius of curvature of the plurality of circular arcs gradually decreases. Or the first curve segment 1122 can be a curve with a single radius of curvature, that is, the first curve segment 1122 is completely composed of a plurality of circular arcs, and the radius of curvature of the plurality of circular arcs is the same. Or, the radius of curvature of the first curve segment 1122 can also be combined, that is to say, part of it has a gradually changing curvature and the other part has a consistent curvature.

[0123] In some embodiments, the first angle is 60 - 75°, for example Figure 14 In the illustrated embodiment, the first angle is 67°. When the first angle is within this range, for the knee joint prosthesis with the femoral condyle prosthesis 100, the posterior cam 120 can maintain contact with the column 220 of the tibial prosthesis 200 during medium flexion, avoiding the femoral condyle prosthesis 100 from slipping relative to the tibial prosthesis 200 during medium flexion, and further improving the stability of the knee joint prosthesis during medium flexion.

[0124] In some embodiments, the second angle is the maximum angle at which the femoral condyle prosthesis 100 can rotate relative to the tibial prosthesis 200. The second angle can generally be 115° - 130°. Please refer to Figure 19 As shown, in some cases, the extreme flexion angle can reach 150°. That is to say, the first curve segment 1122 continuously extends on the condylar joint surface 112 after the posterior cam 120 initially contacts the column 220 of the tibial prosthesis 200, and all parts of this part satisfy the above R 1 relationship formula, further improving the control effect of the contact point position.

[0125] In some embodiments, the L AP , h 1 , l 1 dimension parameters of the femoral condyle prosthesis 100 satisfy at least one of 45mm ≤ L AP ≤ 85mm, 11.6mm ≤ h 1 ≤ 39.8mm, 16.8mm ≤ l 1 ≤ 43.9mm. To meet the needs of most patients for the model of the femoral condyle prosthesis 100. Preferably, the L AP , h 1 , l 1 dimension parameters also satisfy: 48.5mm ≤ L AP ≤ 75.3mm, 12.8mm ≤ h 1 ≤ 34.9mm, 17.9mm ≤ l 1At least one of ≤ 39.7 mm.

[0126] Specifically, the following provides multiple sets of embodiments to illustrate that the femoral condyle prosthesis 100 of the embodiments of the present application can control the contact point between the posterior cam 120 and the column 220 of the tibial prosthesis 200 at a lower position. Among them, as Figure 20 shown, the highest position of the contact point generally appears in the high flexion state during the flexion of the knee joint, usually around 130°. Figure 20 In L 5 When the contact point between the posterior cam 120 and the column 220 of the tibial prosthesis 200 reaches the highest position, the dimension along the fourth direction Y' defined in the embodiments of the present application between the contact point of the two and the lowest contact point of the condylar joint surface 112 and the supporting joint surface 211 of the tibial prosthesis 200. The larger the dimension, the higher the contact point.

[0127] It should also be noted that in the following embodiments, each model of the femoral condyle prosthesis 100 is matched with the tibial prosthesis 200 of a general design corresponding to its own model to complete the experiment. It can be understood that in the embodiments, since the tibial prosthesis 200 of a general design is used, the main influencing factor of the experimental results is each femoral condyle prosthesis 100. For details, please refer to Table 1 below:

[0128]

[0129]

[0130] Please refer to Figure 9 , the tibial prosthesis 200 provided by the embodiments of the present application is used to be fixed to the proximal end of the patient's tibia to replace the proximal tibial joint surface. The tibial prosthesis 200 can be made of materials such as cobalt-chromium-molybdenum metal, titanium-based metal, ceramic, and bioengineering materials to form a tibial tray 230 for connecting the tibia; and made of materials such as ultra-high molecular weight polyethylene, metal materials, ceramic, and bioengineering materials to make a platform 210 and a column 220 for replacing the meniscus function. The tibial prosthesis 200 can be made into an integral structure, that is, the platform 210, the column 220, and the tibial tray 230 can be an integral structure. It can also be that the platform 210 and the column 220 are an integral structure, and the tibial tray 230 is made into a split structure with the other two. Please combine Figure 1 , the tibial prosthesis 200 can cooperate with a compatible femoral condyle prosthesis 100 to form a knee joint prosthesis for replacing the entire knee joint of the patient.

[0131] Specifically, the tibial prosthesis 200 of the embodiments of the present application includes a platform 210 and a column 220, and the platform 210 and the column 220 are used to replace the meniscus of the knee joint. Please combine Figure 10, the platform 210 includes a supporting joint surface 211 and a first end surface 212 and a second end surface 213 that face away from each other along a third direction X'. The supporting joint surface 211 is located between the first end surface 212 and the second end surface 213. The supporting joint surface 211 is used for movably connecting with the condylar joint surface 112 of the femoral condyle prosthesis 100 to support the femoral condyle prosthesis 100 and allow the femoral condyle prosthesis 100 to rotate and move thereon. The column 220 is connected to the platform 210, and the column 220 protrudes from the supporting joint surface 211 along a fourth direction Y'.

[0132] The third direction X' is perpendicular to the fourth direction Y'. When the tibial prosthesis 200 is implanted into the human body, the third direction X' is the direction from the front to the back of the knee joint, and the fourth direction Y' is the direction from the bottom to the top of the human body. Generally speaking, the third direction X' is perpendicular to the human coronal plane in anatomy, and the fourth direction Y' is perpendicular to the human horizontal plane in anatomy.

[0133] Wherein, the column 220 has a cam contact surface 221. The cam contact surface 221 faces away from the first end surface 212. The cam contact surface 221 is used for contacting with the rear cam 120 of the femoral condyle prosthesis 100. That is to say, the first end surface 212 is the front end surface of the platform 210. Correspondingly, the second end surface 213 is the rear end surface of the platform 210.

[0134] Please refer to again Figure 10 , the maximum dimension of the platform 210 along the third direction X' is L AP’ , that is to say, among all the points forming the first end surface 212 and all the points forming the second end surface 213, the distance between the points with the largest distance along the third direction X' is L AP’ . The maximum dimension of the cam contact surface 221 and the second end surface 213 along the third direction X' is l 2 , satisfying: 0.3 ≤ l 2 / L AP’ ≤ 0.42.

[0135] In practical applications, according to the needs of different patients, different sizes and models of the tibial prosthesis 200 are selected, so that the specific dimension of L AP’ can be determined. Based on the specific dimension of L AP’ and the above relationship, the l 2 that meets the requirements can be obtained, and then the shape and dimension of the tibial prosthesis 200 that meets the requirements of this application can be determined. Of course, the specific dimension of l 2 can also be set first, and then based on the specific dimension of l 2 and the above relationship, the L AP’ that meets the requirements can be obtained, and then the shape and dimension of the tibial prosthesis 200 that meets the requirements of this application can be determined.

[0136] For the actual tibial prosthesis 200 product, L AP’ and l 2 can be directly measured by a measuring tool. It is also possible to perform a one-to-one modeling of the tibial prosthesis 200 product through 3D scanning, CAD modeling, object reconstruction, 3D printing, etc., and then geometrically obtain L AP’ and l 2 .

[0137] It can be understood that by setting the L AP’ , l 2 dimension parameters of the tibial prosthesis 200 to satisfy the above relationship, the cam contact surface 221 of its column 220 is located at a suitable position along the third direction X' of the platform 210. Thus, on the one hand, it is possible to control the initial contact angle (i.e., the flexion angle at the initial contact of the two) between the posterior cam 120 of the femoral condyle prosthesis 100 and the cam contact surface 221 during the flexion process of the knee joint. By controlling l 2 / L AP’ within the above range, when the matching femoral condyle prosthesis 100 rotates relative to the tibial prosthesis 200 to flex the knee joint, at a relatively small rotation angle, the posterior cam 120 of the femoral condyle prosthesis 100 can come into contact with the column 220, and keep in contact during moderate flexion and subsequent flexion, avoiding the anterior movement of the femoral condyle prosthesis 100 relative to the tibial prosthesis 200 and preventing instability during moderate flexion; on the other hand, it can help control the contact point of the posterior cam 120 of the femoral condyle prosthesis 100 on the column 220 to remain at a lower position, reduce the force and moment on the column 220, improve the fatigue strength of the column 220, and reduce the risk of fracture of the column 220 and dislocation of the posterior cam 120.

[0138] Please refer to Figure 11 together. In some embodiments, the cam contact surface 221 has a first column curve 2211, a second column curve 2212, and a third column curve 2213 connected in the same reference plane. The first column curve 2211, the second column curve 2212, and the third column curve 2213 are arranged in sequence along the fourth direction Y'. The second column curve 2212 is tangent to the first column curve 2211 and the third column curve 2213 respectively and has different radii of curvature; wherein, the reference plane is parallel to the third direction X' and the fourth direction Y'.

[0139] Among them, the reference plane is a virtual plane. The introduction of the reference plane is to clearly and briefly describe the relevant structure of the tibial prosthesis 200. The reference plane is parallel to the third direction X' and the fourth direction Y', that is, parallel to Figure 9The reference plane is perpendicular to the first direction Z in the tibial prosthesis 200, and when the tibial prosthesis 200 is installed in a human body, the reference plane is parallel to the sagittal plane of the human body in anatomy. It can be known that there are actually countless planes parallel to the third direction X' and the fourth direction Y'. The tibial prosthesis 200 is cut through any plane parallel to the third direction X' and the fourth direction Y' and intersecting with the cam contact surface 221. On the cross section, the edge contour line corresponding to the cam contact surface 221 includes three continuous curves, namely, the first column curve 2211, the second column curve 2212 and the third column curve 2213. The first column curve 2211, the second column curve 2212 and the third column curve 2213 can each be an arc with a curvature radius, and the second column curve 2212 is located between the first column curve 2211 and the third column curve 2213, and the curvature radius of the second column curve 2212 is different from that of the first column curve 2211 and the third column curve 2213.

[0140] Furthermore, in some embodiments, the first column curve 2211 has a curvature center O', and the maximum dimension between the curvature center O' and the second end surface 213 along the third direction X' is l 3 ,satisfy:

[0141] l 3 =i*l 2 -j;

[0142] Among them, i and j are both constants, 0.9≤i≤1, 3.8≤j≤9.8.

[0143] In practical applications, we can first 2 / L AP’ Determine the relationship 2 , and then determine l based on the above relationship 3 , and then determine the position of the curvature center O' of the first column curve 2211, and then combine l 2 The relationship between the first column curve 2211, the second column curve 2212 and the third column curve 2213 of the cam contact surface 221 is obtained to obtain a tibial prosthesis 200 product that meets the requirements of the above relationship. The constants i and j can meet the above ranges. For example, the constant i can be any value among 0.9, 0.92, 0.95, 0.97, 1, or a range between any two values. Preferably, i can be 0.95. For example, the constant f can be any value among 3.8, 4.8, 5.8, 6.8, 7.8, 8.8, 9.8, or a range between any two values. Preferably, f can be 6.8.

[0144] Please refer again Figure 11 In some embodiments, the center of curvature O′ of the first column curve 2211 is located on the side of the second end surface 213 away from the first end surface 212 along the third direction X′.

[0145] In some embodiments, the second column curve 2212 has a center of curvature O 1 ’. In the state of being inserted into the human body, the center of curvature O 1 ’ of the second column curve 2212 and the center of curvature O’ of the first column curve 2211 are arranged in sequence along the third direction X’ in the same plane parallel to the horizontal plane of the human body in anatomy.

[0146] Please refer to again Figure 11 . Specifically, the radius of curvature of the first column curve 2211 is r 2 , satisfying: 15 mm ≤ r 2 ≤ 37 mm. For example, r 2 can be any value among 15 mm, 20 mm, 23 mm, 25 mm, 30 mm, 31 mm, 32 mm, 33 mm, 34 mm, 35 mm, 36 mm, 37 mm or the range value between any two values. The radius of curvature of the second column curve 2212 is r 3 , satisfying: 3 mm ≤ r 3 ≤ 17 mm. For example, r 3 can be any value among 3 mm, 4 mm, 6 mm, 8 mm, 9 mm, 10 mm, 11 mm, 13 mm, 15 mm, 17 mm or the range value between any two values. The radius of curvature of the first column curve 2211 being r 2 and the radius of curvature of the second column curve 2212 being r 3 respectively satisfying the above relationships is beneficial to optimizing the contact point position between the posterior cam 120 and the column 220 of the femoral condyle prosthesis 100, beneficial to controlling the change of the contact point height within a lower range, thereby reducing the force and moment on the column 220, reducing the wear of the column 220, and avoiding the risk of fracture.

[0147] Please refer to again Figure 11 . The maximum dimension l along the third direction X’ of the points forming the second column curve 2212 and the points forming the third column curve 2213 is 4 , satisfying: l 4 ≥ 0.5 mm. Further, the second column curve 2212 is recessed in the opposite direction of the third direction X’ with respect to the third column curve 2213. This reduces the risk of the posterior cam 120 of the femoral condyle prosthesis 100 disengaging from the cam contact surface 221.

[0148] For the actual tibial prosthesis 200 product, the tibial prosthesis 200 product can be modeled one-to-one through three-dimensional scanning, CAD modeling, object reconstruction, 3D printing, etc., and then the above-mentioned r 2 , r 3 , l can be obtained geometrically respectively.3 and l 4 。

[0149] Specifically, multiple groups of embodiments are provided below to illustrate that the tibial prosthesis 200 of the embodiments of the present application can control the initial contact angle between the posterior cam 120 of the femoral condyle prosthesis 100 and the cam contact surface 221 within a small range. Among them, please also refer to Figures 12 to 19 , as the knee joint flexes, the posterior cam 120 goes from never contacting the cam contact surface 221 to Figure 14 the initial contact state, and then continuously contacts until the maximum flexion angle. Among them, each model of femoral condyle prosthesis 100 uses a matching universal tibial prosthesis 200.

[0150] It should also be noted that in the following embodiments, each model of tibial prosthesis 200 cooperates with a femoral condyle prosthesis 100 with a universal design that matches its respective model to complete the experiment. It can be understood that in the embodiments and the comparative examples, since the femoral condyle prosthesis 100 with a universal design is used, the main influencing factor of the experimental results is each tibial prosthesis 200. For details, please refer to Table 2 below:

[0151] Serial number <![CDATA[L AP’ / mm]]> <![CDATA[l 2 / mm]]> <![CDATA[l 2 / L AP’ > Initial contact angle Example 21 36 15 0.42 75° Example 22 38.5 13 0.34 65° Example 23 42.6 17 0.40 75° Example 24 46.9 15 0.32 63° Example 25 49.1 17 0.35 67° Example 26 52.6 15.8 0.30 60° Example 27 57 21.8 0.38 69°

[0152] Please refer again to Figure 1 , the knee joint prosthesis of the embodiments of the present application includes a femoral condyle prosthesis 100 and a tibial prosthesis 200. The femoral condyle prosthesis 100 is used to be fixed to the distal end of the patient's femur 300 to replace the distal joint surface of the femur 300. The femoral condyle prosthesis 100 can be made of materials such as cobalt-chromium-molybdenum metal, titanium-based metal, ceramic, and bioengineering materials. The tibial prosthesis 200 is used to be fixed to the proximal end of the patient's tibia to replace the proximal tibial joint surface. The tibial prosthesis 200 can be made of cobalt-chromium-molybdenum metal, titanium-based metal, ceramic, and bioengineering materials to make a tibial tray 230 for connecting the tibia; it is made of ultra-high molecular weight polyethylene, metal materials, ceramic, and bioengineering materials to make a platform 210 and columns 220 for replacing the meniscus function. The tibial prosthesis 200 can be made into an integral structure, that is, the platform 210, the columns 220, and the tibial tray 230 can be an integral structure. It is also possible to make the platform 210 and the columns 220 into an integral structure, and the tibial tray 230 is made into a split structure with the other two. The tibial prosthesis 200 cooperates with the femoral condyle prosthesis 100 to form a knee joint prosthesis for replacing the entire knee joint of the patient.

[0153] The femoral condyle prosthesis 100 includes a first condyle 110a, a second condyle 110b, and a posterior cam 120. The first condyle 110a and the second condyle 110b can respectively correspond to the medial condyle and the lateral condyle of the femur 300. The first condyle 110a and the second condyle 110b are arranged along a first direction Z, and an intercondylar notch 113 is defined between them. It should be noted that the first direction Z refers to the arrangement direction of the first condyle 110a and the second condyle 110b. According to the actual state of the femoral condyle prosthesis 100 in space, the first direction Z can be any direction in space; when the femoral condyle prosthesis 100 is implanted into the human body, the first direction Z is the direction from the inside to the outside or from the outside to the inside of the knee joint. Generally speaking, the first direction Z is perpendicular to the sagittal plane of the human body in anatomy.

[0154] Wherein, at least one of the first condyle 110a and the second condyle 110b has a condylar joint surface 112. Please refer to Figure 4 , and the condylar joint surface 112 is used to replace the original joint surface of the femur 300. Preferably, both the first condyle 110a and the second condyle 110b have a condylar joint surface 112.

[0155] The posterior cam 120 is disposed in the intercondylar notch 113 and is connected to at least one of the first condyle 110a and the second condyle 110b. During the flexion of the knee joint, the femoral condyle prosthesis 100 rotates and slides relative to the tibial prosthesis 200. The posterior cam 120 is used to contact the column 220 of the tibial prosthesis 200 to achieve mutual support and ensure the stability of the knee joint flexion. Preferably, the posterior cam 120 is respectively connected to the first condyle 110a and the second condyle 110b.

[0156] The tibial prosthesis 200 includes a platform 210 and a column 220. The platform 210 and the column 220 are used to replace the meniscus of the knee joint. Please refer to Figure 10 , the platform 210 includes a supporting joint surface 211. The column 220 is connected to the platform 210 and protrudes relative to the supporting joint surface 211 along a fourth direction Y'. The femoral condyle prosthesis 100 can rotate relative to the tibial prosthesis 200. During the rotation process, the condylar joint surface 112 contacts the supporting joint surface 211. The maximum dimension of the tibial prosthesis 200 along a third direction X' is L AP’ , and the maximum dimension of the femoral condyle prosthesis 100 along the third direction X' is L AP , the third direction X' is perpendicular to the first direction Z and the fourth direction Y'. When the knee joint prosthesis is implanted into the human body, the third direction X' is the direction from the front to the back of the knee joint, the fourth direction Y' is the direction from the bottom to the top of the human body, and the first direction Z is the direction from the inside to the outside or from the outside to the inside of the knee joint. Generally speaking, the third direction X' is perpendicular to the coronal plane of the human body in anatomy, the fourth direction Y' is perpendicular to the horizontal plane of the human body in anatomy, and the first direction Z is perpendicular to the sagittal plane of the human body in anatomy.

[0157] See also Figure 8 and Figure 14 The condylar joint surface 112 has a condylar curve 1121 and a first contact point P and a second contact point Q located on the condylar curve 1121 in a reference plane perpendicular to the first direction Z, and the supporting joint surface 211 has a supporting curve 2111 in the same reference plane, and the supporting curve 2111 is opposite to the condylar curve 1121.

[0158] The reference plane is a virtual plane. The reference plane is introduced to clearly and briefly describe the relevant structure of the knee joint prosthesis. The reference plane is perpendicular to the first direction Z. When the knee joint prosthesis is installed in the human body, the reference plane is parallel to the sagittal plane of the human body in anatomy. It can be seen that there are actually countless planes perpendicular to the first direction Z. The knee joint prosthesis is cut through any plane perpendicular to the first direction Z and intersecting with the condylar joint surface 112. On the cross section, the edge contour line corresponding to the condylar joint surface 112 is the condylar curve 1121, and the first contact point P and the second contact point Q are two points on the condylar curve 1121; on the cross section, the edge contour line corresponding to the support joint surface 211 is the support curve 2111. The support curve 2111 is opposite to the condylar curve 1121, and the two can contact during the knee joint flexion process.

[0159] When the femoral condyle prosthesis 100 rotates a first angle relative to the tibial prosthesis 200, the first contact point P contacts the support curve 2111, and the posterior cam 120 initially contacts the column 220; when the femoral condyle prosthesis 100 rotates a second angle relative to the tibial prosthesis 200, the second contact point Q contacts the support curve 2111, and the second angle is greater than the first angle. In other words, during the flexion of the knee joint, at the moment when the posterior cam 120 of the femoral condyle prosthesis 100 contacts the column 220 of the tibial prosthesis 200, the first contact point P contacts the support joint surface 211, and the flexion angle of the knee joint is the first angle. During the continued flexion of the knee joint, the second contact point Q can contact the support joint surface 211, and the second contact point Q is a point of the femoral condyle prosthesis 100 that is more posterior (relative to the human body position) than the first contact point P.

[0160] Please refer again Figure 8 The portion of the condylar curve 1121 between the first contact point P and the second contact point Q is a first curve segment 1122. At least a portion of the first curve segment 1122 is a circular arc, and the radius of curvature of the circular arc of the first curve segment 1122 is R. 1 The supporting curve 2111 includes a second curved segment 2112 opposite to the first curved segment 1122, at least part of the second curved segment 2112 is a circular arc, and the radius of curvature of the circular arc of the second curved segment 2112 is R 2 , satisfying: Rmin≤R 1 ≤Rmax <R 2 ;

[0161] wherein, Rmin = e * L AP - f, Rmax = e' * L AP - f', R 2 = g * L AP’ - m;

[0162] e, f, e', f', g, and m are all constants, 0.22 ≤ e ≤ 0.24, -2.5 ≤ f ≤ 3.5, 0.41 ≤ e' ≤ 0.45, 2.6 ≤ f' ≤ 8.6, 1.72 ≤ g ≤ 1.74, 8 ≤ m ≤ 13.

[0163] That is to say, e * L AP - f ≤ R 1 ≤ e' * L AP - f' < R 2 = g * L AP’ - m. In practical applications, according to the needs of different patients, femoral condyle prostheses 100 of different sizes and models are selected, so that the specific size of L AP can be determined. Based on the specific size of L AP and the above relationships, R 1 can be controlled. According to the specific size of L AP of the femoral condyle prosthesis 100 and the needs of different patients, the specific size of L AP’ can be determined. Based on the specific size of L AP’ and the above relationships, R 2 can be controlled.

[0164] The constants e, f, e', f', g, and m only need to satisfy the above ranges. For example, the constant e can be any value among 0.22, 0.23, 0.24 or the range value between any two values. Preferably, e can be 0.23. For example, the constant f can be any value among -2.5, -1.5, -0.5, 0.5, 1.5, 2.5, 3.5 or the range value between any two values. Preferably, f can be 0.5. For example, the constant e' can be any value among 0.41, 0.42, 0.43, 0.44, 0.45 or the range value between any two values. Preferably, the constant e' can be 0.43. For example, the constant f' can be any value among 2.6, 3.6, 4.6, 5.6, 6.6, 7.6, 8.6 or the range value between any two values. Preferably, f' can be 6.6. For example, the constant g can be any value among 1.72, 1.73, 1.74 or the range value between any two values. Preferably, g can be 1.73. For example, the constant m can be any value among 8, 9, 10, 11, 12, 13 or the range value between any two values. Preferably, m can be 11.1.

[0165] By controlling R 1 within the above range, the movement trajectory of the condylar joint surface 112 during knee flexion can be controlled, especially the movement trajectory of the condylar joint surface 112 after the posterior cam 120 initially contacts the column 220 of the tibial prosthesis 200, thereby optimizing the relative movement trajectory between the posterior cam 120 and the condylar joint surface 112, reducing the height of the posterior cam 120 relative to the lowest point of the condylar joint surface 112, and facilitating the reduction of the contact point position between the posterior cam 120 and the column 220 of the tibial prosthesis 200. At the same time, by controlling R 2 within the above range, making R 2 greater than R 1 , during the flexion of the knee prosthesis, when the femoral condyle prosthesis 100 rotates relative to the tibial prosthesis 200 until the posterior cam 120 contacts the column 220 and then the femoral condyle prosthesis 100 continues to rotate relative to the tibial prosthesis 200, the supporting joint surface 211 corresponding to the second curve segment 2112 has a larger radius of curvature, so it will not cause interference in the rotation space of the condylar joint surface 112 corresponding to the first curve segment 1122, and can prevent the rotating femoral condyle prosthesis 100 from being lifted, thus facilitating the control of the contact point of the posterior cam 120 on the column 220 to remain at a lower position. Furthermore, the pressure of the posterior cam 120 on the column 220 can always be maintained at a lower level, avoiding wear of the posterior cam 120 and the column 220 due to excessive pressure between the two, and at the same time, effectively maintaining the fatigue strength of the column 220 and reducing the risk of fracture of the column 220 and dislocation of the posterior cam 120.

[0166] Specifically, please refer to Figure 12 , in some embodiments, the knee prosthesis satisfies: 45 mm ≤ L AP ≤ 85 mm, 36 mm ≤ L AP’ ≤ 57 mm. For example, L AP can be any value among 45 mm, 55 mm, 65 mm, 75 mm, 85 mm or the range value between any two numerical values. For example, L AP’ can be any value among 36 mm, 40 mm, 45 mm, 50 mm, 55 mm, 57 mm or the range value between any two numerical values.

[0167] Furthermore, it satisfies: 2.4 ≤ R 2 / R 1 ≤ 6.5. For example, R 2 / R 1 can be any value among 2.4, 3, 4, 5, 6, 6.5 or the range value between any two numerical values. Preferably, 2.9 ≤ R 2 / R 1 ≤ 4.8.

[0168] In some embodiments, the second curve segment 2112 includes a plurality of connected circular arcs, and the curvature radii of the plurality of circular arcs are gradually changed or remain the same. That is to say, the second curve segment 2112 can be a gradually changing curve, that is, the second curve segment 2112 is completely composed of a plurality of circular arcs, and the curvature radii of the plurality of circular arcs gradually decrease or gradually increase. Or the second curve segment 2112 can be a curve with a single curvature radius, that is, the second curve segment 2112 is completely composed of a plurality of circular arcs, and the curvature radii of the plurality of circular arcs are the same. Or, the curvature radius of the second curve segment 2112 can also be combined, that is to say, part of it has a gradually changing curvature and the other part has a consistent curvature.

[0169] Please also combine Figure 5 and Figure 11 , in some embodiments, the column 220 has a cam contact surface 221, and the cam contact surface 221 is used to contact the rear cam 120. The rear cam 120 has a contour curve 121 in a reference plane perpendicular to the first direction Z, at least part of the contour curve 121 is an arc line 1211, and the cam contact surface 221 has a first column curve 2211, a second column curve 2212 and a third column curve 2213 connected in the same reference plane. The first column curve 2211, the second column curve 2212 and the third column curve 2213 are arranged in sequence along the fourth direction Y', and the second column curve 2212 is tangent to the first column curve 2211 and the third column curve 2213 respectively and has different curvature radii; wherein, the curvature radius of the arc line 1211 is r 1 , the curvature radius of the first column curve 2211 is r 2 , satisfying: r 2 > r 1 . The curvature radius of the first column curve 2211 is r 2 greater than the curvature radius of the arc line 1211 which is r 1 , which is beneficial to controlling the position of the contact point after the rear cam 120 contacts the column 220 and making the position height of the contact point lower.

[0170] Furthermore, it also satisfies: 1.5 ≤ r 2 / r 1 ≤ 4.5. For example, r 2 / r 1 can be any value among 1.5, 2, 3, 4, 4.5 or a range value between any two numerical values.

[0171] For an actual knee joint prosthesis product, the knee joint prosthesis product can be modeled one-to-one through three-dimensional scanning, CAD modeling, object reconstruction, 3D printing, etc., and then L can be obtained geometrically respectively AP , L AP’, R 1 , R 2 , r 1 and r 2 .

[0172] Specifically, the following provides multiple sets of embodiments to illustrate that the knee joint prosthesis of the embodiments of the present application has a good effect on controlling the contact point position between the posterior cam 120 and the column 220. Among them, as Figure 20 shown, the highest position of the contact point generally appears in the high flexion state during the flexion process of the knee joint, usually around 130°, Figure 20 where L 5 is the dimension along the fourth direction Y' defined in the embodiments of the present application between the contact point of the posterior cam 120 and the column 220 of the tibial prosthesis 200 when the contact point reaches the highest position and the lowest contact point between the condylar joint surface 112 and the supporting joint surface 211 of the tibial prosthesis 200. The larger the dimension, the higher the contact point. For details, please refer to Table 3 below:

[0173]

[0174] The embodiments of the present application also provide a knee joint prosthesis, which includes the femoral condyle prosthesis 100 in the above embodiments; and / or, the tibial prosthesis 200 in the above embodiments. It can be understood that this knee joint prosthesis can have all the technical features and beneficial effects of the above femoral condyle prosthesis 100 and / or tibial prosthesis 200, and the femoral condyle prosthesis 100 and the tibial prosthesis 200 have been described in detail above and will not be elaborated here.

[0175] In the above embodiments, the descriptions of each embodiment have their own emphases. For the parts not detailed in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0176] The above has introduced in detail the femoral condyle prosthesis, the tibial prosthesis and the knee joint prosthesis provided by the embodiments of the present application, and specific examples have been used to elaborate the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the technical solution and its core idea of the present application; those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A femoral condyle prosthesis, characterized in that, comprising: a first condyle and a second condyle arranged along a first direction, an intercondylar notch being defined between the first condyle and the second condyle, at least one of the first condyle and the second condyle having a connecting surface and a condylar articular surface facing away from the connecting surface, the connecting surface being for connecting the osteotomy distal end surface of the femur; A rear cam, the rear cam is disposed in the intercondylar notch and connected to at least one of the first condyle and the second condyle; at least one cross-section of the rear cam perpendicular to the first direction has a contour curve, and the distance between the point on the contour curve closest to the first reference plane AA' and the first reference plane AA' is h 1 ; the first reference plane AA' is parallel to the connecting surface and tangent to the condylar joint surface at the tangent point O; The distance between the point on the contour curve that is farthest from the second reference plane BB' and the second reference plane BB' is l 1 ; The second reference plane BB' passes through the tangent point O, is parallel to the first direction, and is perpendicular to the connecting surface; The maximum dimension of the femoral condyle prosthesis along the second direction is L AP , and the second direction is perpendicular to the second reference plane BB'; satisfying: L AP = a * h 1 + b, and, L AP = c * l 1 - d; wherein a, b, c, and d are all constants, 2.0 ≤ a ≤ 2.9, 5.5 ≤ b ≤ 11.5, 2.3 ≤ c ≤ 3.3, 10.5 ≤ d ≤ 16.

2. The femoral condyle prosthesis according to claim 1, characterized in that, At least part of the contour curve is an arc line, and the radius of curvature of the arc line is r 1 , satisfying: 1 mm ≤ r 1 ≤ 20 mm.

3. The femoral condyle prosthesis according to claim 2, characterized in that, the contour curve comprises a plurality of the arc lines, the plurality of arc lines being connected in sequence, and two adjacent arc lines being tangent to each other, and the curvature radii of at least two adjacent arc lines being different.

4. The femoral condyle prosthesis according to any one of claims 1 to 3, characterized in that, the femoral condyle prosthesis is capable of rotating relative to the tibial prosthesis, and during the rotation, the condylar articular surface contacts the supporting articular surface of the tibial prosthesis; the condylar articular surface has a condylar curve and a first contact point P and a second contact point Q located on the condylar curve in a reference plane perpendicular to the first direction; when the femoral condyle prosthesis rotates relative to the tibial prosthesis by a first angle, the first contact point P contacts the supporting articular surface, and the posterior cam initially contacts the column of the tibial prosthesis; when the femoral condyle prosthesis rotates relative to the tibial prosthesis by a second angle, the second contact point Q contacts the supporting articular surface, the second angle being greater than the first angle; The portion of the condylar curve between the first contact point P and the second contact point Q is a first curve segment, at least part of the first curve segment is an arc, and the radius of curvature of the arc of the first curve segment is R 1 , satisfying: Rmin≤R 1 ≤Rmax, and Rmin = e*L AP -f, Rmax = e’*L AP -f’; wherein e, f, e', and f' are all constants, 0.22 ≤ e ≤ 0.24, -2.5 ≤ f ≤ 3.5, 0.41 ≤ e' ≤ 0.45, 2.6 ≤ f' ≤ 8.

6.

5. The femoral condyle prosthesis according to claim 4, characterized in that, It also satisfies: 6.4 mm ≤ R 1 ≤ 35.6 mm.

6. The femoral condyle prosthesis according to claim 4, characterized in that, the first curve segment comprises a plurality of connected arcs, and from the first contact point P to the second contact point Q, the curvature radii of the plurality of arcs gradually decrease or remain the same.

7. The femoral condyle prosthesis according to claim 4, characterized in that, the first angle is 60 - 75°.

8. The femoral condyle prosthesis according to claim 4, characterized in that, the second angle is the maximum angle by which the femoral condyle prosthesis can rotate relative to the tibial prosthesis.

9. The femoral condyle prosthesis according to claim 1, characterized in that, Satisfy: 45mm ≤ L AP ≤ 85mm, 11.6mm ≤ h 1 ≤ 39.8mm, 16.8mm ≤ l 1 ≤ at least one of 43.9mm.

10. The femoral condyle prosthesis according to claim 9, characterized in that, It also satisfies: 48.5 mm ≤ L AP ≤ 75.3 mm, 12.8 mm ≤ h 1 ≤ 34.9 mm, 17.9 mm ≤ l 1 ≤ at least one of 39.7 mm.

11. The femoral condyle prosthesis according to claim 1, characterized in that, the constant a satisfies: 2.2 ≤ a ≤ 2.6, and / or, the constant c satisfies: 2.6 ≤ c ≤ 3.

0.

12. The femoral condyle prosthesis according to claim 1, characterized in that, both the first condyle and the second condyle have the connecting surface and the condylar articular surface; the posterior cam is respectively connected to the first condyle and the second condyle.

13. The femoral condyle prosthesis according to claim 1, characterized in that, all cross-sections of the rear cam perpendicular to the first direction have the profile curve.

14. A tibial prosthesis, characterized in that, comprising: a platform, the platform includes a bearing joint surface and a first end surface and a second end surface that face away from each other along a third direction, the bearing joint surface is located between the first end surface and the second end surface, and the bearing joint surface is used for movably connecting with the condylar joint surface of the femoral condyle prosthesis; a column, connected to the platform and protruding along a fourth direction from the bearing joint surface, the third direction being perpendicular to the fourth direction; the column has a cam contact surface, the cam contact surface faces away from the first end surface, and the cam contact surface is used for contacting the rear cam of the femoral condyle prosthesis; The maximum dimension of the platform along the third direction is L AP’ , and the maximum dimension between the cam contact surface and the second end face along the third direction is l 2 , satisfying: 0.3 ≤ l 2 / L AP’ ≤ 0.42 15. The tibial prosthesis according to claim 14, characterized in that, the cam contact surface has a first column curve, a second column curve and a third column curve connected in the same reference plane, the first column curve, the second column curve and the third column curve are arranged in sequence along the fourth direction, and the second column curve is tangent to the first column curve and the third column curve respectively and has different curvature radii; wherein, the reference plane is parallel to the third direction and the fourth direction.

16. The tibial prosthesis according to claim 15, characterized in that, The first column curve has a curvature center O', and the maximum dimension along the third direction between the curvature center O' and the second end face is l 3 , satisfying: l 3 = i * l 2 -j; wherein, both i and j are constants, 0.9 ≤ i ≤ 1, 3.8 ≤ j ≤ 9.

8.

17. The tibial prosthesis according to claim 15 or 16, characterized in that, The radius of curvature of the first column curve is r 2 , satisfying: 15 mm ≤ r 2 ≤ 37 mm; the radius of curvature of the second column curve is r 3 , satisfying: 3 mm ≤ r 3 ≤ 17 mm.

18. The tibial prosthesis according to claim 15, characterized in that, The maximum dimension in the third direction between the point forming the second column curve and the point forming the third column curve is l 4 , satisfying: l 4 ≥0.5 mm.

19. A knee joint prosthesis, characterized in that, comprising: a femoral condyle prosthesis, the femoral condyle prosthesis includes a first condyle, a second condyle and a rear cam, the first condyle and the second condyle are arranged along a first direction, an intercondylar notch is defined between the first condyle and the second condyle, and at least one of the first condyle and the second condyle has a condylar joint surface; the rear cam is arranged in the intercondylar notch and is connected to at least one of the first condyle and the second condyle; a tibial prosthesis, the tibial prosthesis includes a platform and a column, the platform includes a bearing joint surface, and the column is connected to the platform and protrudes along a fourth direction relative to the bearing joint surface; The femoral condyle prosthesis can rotate relative to the tibial prosthesis. During the rotation, the condylar joint surface contacts the supporting joint surface; the maximum dimension of the tibial prosthesis along the third direction is L AP’ , and the maximum dimension of the femoral condyle prosthesis along the third direction is L AP , and the third direction is perpendicular to the first direction and the fourth direction; the condylar joint surface has a condylar curve and a first contact point P and a second contact point Q located on the condylar curve in a reference plane perpendicular to the first direction, the bearing joint surface has a bearing curve in the same reference plane, and the bearing curve is opposite to the condylar curve; when the femoral condyle prosthesis rotates relative to the tibial prosthesis by a first angle, the first contact point P contacts the bearing curve, and the rear cam initially contacts the column; when the femoral condyle prosthesis rotates relative to the tibial prosthesis by a second angle, the second contact point Q contacts the bearing curve, and the second angle is greater than the first angle; The portion of the condylar curve between the first contact point P and the second contact point Q is a first curve segment, at least part of the first curve segment is an arc, and the radius of curvature of the arc of the first curve segment is R 1 ; The support curve includes a second curve segment opposite to the first curve segment, at least part of the second curve segment is an arc, and the radius of curvature of the arc of the second curve segment is R 2 , satisfying: Rmin≤R 1 ≤Rmax<R 2 ; wherein, Rmin = e * L AP - f, Rmax = e' * L AP - f', R 2 = g * L AP’ - m; e, f, e’, f’, g, and m are all constants, where 0.22 ≤ e ≤ 0.24, -2.5 ≤ f ≤ 3.5, 0.41 ≤ e’ ≤ 0.45, 2.6 ≤ f’ ≤ 8.6, 1.72 ≤ g ≤ 1.74, and 8 ≤ m ≤ 13.

20. The knee joint prosthesis according to claim 19, wherein, Satisfy: 45mm ≤ L AP ≤ 85mm, 36mm ≤ L AP’ ≤ 57mm.

21. The knee joint prosthesis according to claim 19, wherein, Satisfy: 2.4 ≤ R 2 / R 1 ≤ 6.

5.

22. The knee joint prosthesis according to claim 21, wherein, It also satisfies: 2.9 ≤ R 2 / R 1 ≤ 4.

8.

23. The knee joint prosthesis according to claim 19, wherein, the second curve segment includes multiple connected circular arcs, and the curvature radii of the multiple circular arcs change gradually or remain the same.

24. The knee joint prosthesis according to any one of claims 19 to 23, wherein, the column has a cam contact surface for contacting the rear cam; the rear cam has a contour curve in a reference plane perpendicular to the first direction, at least part of the contour curve being an arc line, and the cam contact surface has a first column curve, a second column curve, and a third column curve connected in the same reference plane, the first column curve, the second column curve, and the third column curve being arranged in sequence along the fourth direction, and the second column curve being tangent to the first column curve and the third column curve respectively and having different curvature radii; Among them, the radius of curvature of the arc line is r 1 , and the radius of curvature of the first column curve is r 2 , satisfying: r 2 > r 1 .

25. The knee joint prosthesis according to claim 24, wherein, It also satisfies: 1.5 ≤ r 2 / r 1 ≤ 4.

5.

26. A knee joint prosthesis, wherein, comprising: a femoral condyle prosthesis according to any one of claims 1 to 13; and / or, a tibial prosthesis according to any one of claims 14 to 18.

Images