KR102608868B1 - Tibia Bearing component for a Knee Prosthesis With Reverse Slope - Google Patents

Abstract

The present invention relates to an artificial knee joint bearing element having a reverse inclination, and more specifically, to a bearing body having a curved shape and an articular surface that is recessed downward, so that the artificial knee joint femoral element can slide on the articular surface. It is provided to extend downward from the bearing body and is in contact with the tibial element, and includes an inclined portion formed to be inclined to at least one side, wherein the inclined portion extends downward from the bearing body from the front to the rear, so that the overall inclination of the artificial knee joint system is gentle. However, by cutting the tibia according to the patient's unique tibial slope to avoid excessive fracture, it has a reverse slope that can reduce complications and sequelae after artificial knee joint replacement surgery and improve the durability of artificial knee joint implants. This relates to artificial knee joint bearing elements. The present invention is a bearing element with a reverse slope, in contrast to the gentle rear slope of existing bearings, and when the lower surface is placed on the ground horizontally, the front is low and the rear is high, It has a reverse slope that is high at the front and low at the back in conventional bearing designs.

Description

Tibia Bearing component for a Knee Prosthesis With Reverse Slope}

The present invention relates to an artificial knee joint bearing element having a reverse inclination, and more specifically, to a bearing body having a curved shape and an articular surface that is recessed downward, so that the artificial knee joint femoral element can slide on the articular surface. It extends downward from the bearing body and is provided to contact the tibial element, and includes an inclined portion formed to be inclined to at least one side, wherein the inclined portion is formed to have a forward inclination rising from the rear to the front, so that the bearing body moves from the front to the rear. The overall slope of the artificial knee joint system is maintained gently, but the tibia is cut along the patient's unique tibial slope to avoid excessive fracture removal, thereby reducing complications and aftereffects after artificial knee joint replacement surgery. This relates to an artificial knee joint bearing element with a reverse slope that can improve the durability of the knee joint insert. The present invention is a bearing element with a reverse slope, in contrast to the gentle rear slope of existing bearings, and when the lower surface is placed on the ground horizontally, the front is low and the rear is high, It has a reverse slope that is high at the front and low at the back in conventional bearing designs. In addition, in the present invention, the lower surface of the bearing has a reverse slope as a mirror image of the tibial resection surface having a posterior slope.

The knee joint refers to a joint formed by the three bones surrounding the knee, the femur, tibia, and patella. It supports the weight of a person and is used for leg movements such as walking or running through joint movements. It corresponds to the key joints involved. When the knee joint does not function properly due to various causes such as degenerative arthritis of the knee or post-traumatic arthritis, knee joint replacement surgery, which involves inserting an implant that can replace the damaged knee joint into the patient's bone, is suggested as an orthopedic treatment method. It is being implemented.

Figure 1 is a diagram showing a conventional artificial knee joint, and the prior art is disclosed in Korean Patent Publication No. 10-1184905 (2012.09.20). Hereinafter, it will be described with reference to FIG. 1.

Total knee replacement surgery is a surgery in which part of the femur (F) and tibia (T) is incised when the knee joint is damaged and an artificial knee joint implant is replaced and inserted into the incised area. The femoral element (91) is placed in the distal portion of the femur (Distal Portion). Artificial knee joint implant transplantation surgery is performed by fixing the tibial element 93 to the proximal portion of the tibia and placing the bearing element 95 between the femoral element 91 and the tibial element 93. It will be performed.

The artificial knee joint bearing element used today is made of polyethylene and is combined with the tibial element 93, which is a replacement for the tibia, and is provided to come into contact with the femoral element 91, so that the femoral element 91 moves on the bearing element 95. At this time, in order to reduce friction between the femoral element 91 and the bearing element 95, maximize joint movement, and approximate the movement of the human knee, the upper surface of the bearing element 95 is concave in the shape of being indented to the lower or distal side. ) The articular surface is formed, and the lower surface is trimmed flat to be parallel to the ground or perpendicular to the mechanical axis of the tibia (T).

Meanwhile, in order to insert the tibial element 93 into the tibia, the tibia is cut flat. Generally, during artificial joint surgery, the cutting surface is made at an angle parallel to the ground or inclined posteriorly within about 5 degrees from the ground (average: about 5 degrees). It is being resected to have a posterior inclination of 3 degrees. Forming the cutting surface to achieve such a gentle posterior slope (high at the front and low at the rear) can reduce mechanical wear and increase the stability of the artificial knee joint.

In comparison, as can be seen in Figure 2, the tibial plateau (upper surface) of a person has a posterior slope that decreases from the front to the back at an angle greater than 5 degrees from the ground. Depending on the shape of the tibia, the relatively hard cortical bone (CoT) is located just below the joint surface, and the relatively soft cancellous bone (CaT) is located inside it. The average posterior tilt of the tibia before amputation in humans has been studied to be between about 7 and 20 degrees, with significant individual differences. For patients in the Asian region, the average is about 14 degrees. Therefore, when the tibia is cut to have a posterior inclination of about 3 degrees without considering the natural posterior inclination of the tibia, the amount of bone resected on the anterior side becomes excessively large compared to the posterior side, and the relatively hard cortical bone on the anterior side ( Removing all of the CoT) weakens bone strength and may cause postoperative sequelae or complications such as pain when walking and collapse of the artificial knee joint. However, there is still no solution to improve the problems that occur in patients with such a large posterior tilt.

Therefore, in the art, the cutting angle of the tibia is adjusted to the posterior inclination of the human tibia as much as possible to reduce the amount of bone cutting, and the slope is relatively parallel to the ground with the femoral element that contacts through the articular surface when combined with the tibial element. There is a demand for artificial knee joint bearing elements that are highly durable while reproducing natural joint movements.

Korean Patent Publication No. 10-1184905 (2012.09.20.)

The present invention was devised to solve the above problems,

The object of the present invention is to provide a bearing body that has a curved shape and an articular surface indented downward so that the femoral element of an artificial knee joint can slide on the articular surface, and is provided to extend downward from the bearing body to contact the tibial element. However, the overall slope of the artificial knee joint system, including the slope formed to slope to at least one side, is maintained gently, but the tibia is cut according to the patient's unique tibial slope to avoid excessive fracture preparation. Alternatively, an artificial knee joint bearing element with a reverse inclination is provided.

The purpose of the present invention is to provide a lower surface inclined portion that is formed to have an anterior inclination and extends downward from the bearing body from the front to the rear, thereby reducing complications and aftereffects after artificial knee joint replacement surgery and improving the durability of the artificial knee joint insert. The purpose is to provide an artificial knee joint bearing element with a reverse inclination.

The object of the present invention is that the inclined portion includes an inclined surface extending backward with a constant inclination, an outer circumferential surface extending up and down along the circumference of the bearing body, and a connection surface formed between the inclined surface to load the load transmitted from the femoral element. The aim is to provide an artificial knee joint bearing element with a reverse inclination that stably transmits the force to the obliquely cut tibia.

The purpose of the present invention is that it can be applied to artificial knee joint procedures that form a tibial cutting surface using the existing method, and provides an additional extension angle so that the knee can be better straightened after artificial joint surgery in patients with flexion contracture that does not fully straighten the knee. The purpose is to provide an artificial knee joint bearing element with a reverse inclination.

The purpose of the present invention is to provide an artificial knee joint bearing element in which the connecting surface extends along the outer peripheral surface at the same inclination as the outer peripheral surface and has a reverse inclination connected perpendicularly to the inclined surface.

The purpose of the present invention is that at least a portion of the connecting surface is bent and extended from one end of the outer peripheral surface toward the center, and at least a portion of the connecting surface extends at a different inclination from the outer peripheral surface, so that a bearing element of a relatively large size is provided even on a narrow tibial cutting surface. The purpose is to provide an artificial knee joint bearing element with a reverse inclination that can be seated.

The purpose of the present invention is that the outer peripheral surface includes a front outer peripheral surface that constitutes the perimeter of the bearing body at the front of the bearing body and a rear outer peripheral surface that constitutes the perimeter of the bearing body at the rear of the bearing body, and is connected to the rear outer peripheral surface at the rear end. An artificial knee joint bearing element with a reverse inclination is provided so that the vertical length along which the surface extends is longer than the vertical length over which the front outer peripheral surface extends at the front end.

The purpose of the present invention is that the articular surface is defined as the lowest point that is most indented downward on the anteroposterior cross section and the first low point where the vertical distance from the articular surface surface to the lower slope is shortest, and the first low point is anterior to the lowest point. To provide an artificial knee joint bearing element having a reverse slope formed on the side and improving durability from vertical load.

The purpose of the present invention is to provide a tibial cutting surface in which the front outer peripheral surface and the rear outer peripheral surface extend vertically from the lower surface of the bearing body, and the inclined surface extends backward and is inclined with a predetermined inclination with respect to the lower surface of the bearing body. The aim is to provide an artificial knee joint bearing element with a reverse slope that allows the bearing element to extend in the direction of the anatomical axis of the tibia.

The purpose of the present invention is to provide an artificial knee joint bearing element with a reverse inclination extending up and down while the front outer peripheral surface and the rear outer peripheral surface have a predetermined angle so as to be perpendicular to the inclined surface.

In order to achieve the above-described object, the present invention is implemented by an embodiment having the following configuration.

According to one embodiment of the present invention, the artificial knee joint bearing element with a reverse inclination according to the present invention has a curved shape and has a joint surface that is recessed downward, so that the artificial knee joint femoral element can slide on the joint surface. The body extends downward from the bearing body and is provided to contact the tibial element, and includes an inclined portion formed to be inclined to at least one side.

According to another embodiment of the present invention, the lower surface slope of the artificial knee joint bearing element with a reverse slope according to the present invention is formed to have a forward slope and extends downward from the bearing body from the front to the rear. .

According to another embodiment of the present invention, the inclined portion of the artificial knee joint bearing element with a reverse inclination according to the present invention includes an inclined surface extending backward with a constant inclination, an outer peripheral surface extending up and down along the circumference of the bearing body, and It is characterized by comprising a connecting surface formed between the inclined surfaces.

According to another embodiment of the present invention, the connecting surface of the artificial knee joint bearing element with a reverse inclination according to the present invention is characterized in that it extends along the outer peripheral surface at the same inclination as the outer peripheral surface.

According to another embodiment of the present invention, at least a portion of the connecting surface of the artificial knee joint bearing element with a reverse inclination according to the present invention is bent and extended from one end of the outer peripheral surface toward the center, and at least a portion of the connecting surface has an inclination different from the outer peripheral surface. It is characterized by extending to .

According to another embodiment of the present invention, the inclination of the lower slope of the artificial knee joint bearing element with a reverse inclination according to the present invention is characterized in that it is 3 degrees or more and 7 degrees or less.

According to another embodiment of the present invention, the outer circumferential surface of the artificial knee joint bearing element with a reverse inclination according to the present invention is the front outer circumferential surface constituting the circumference of the bearing body at the front of the bearing body and the outer circumferential surface of the bearing body at the rear of the bearing body. It includes a rear outer peripheral surface constituting the perimeter, and is characterized in that the vertical length extending between the rear outer peripheral surface and the connecting surface at the rear end is longer than the vertical length extending the front outer peripheral surface at the front end.

According to another embodiment of the present invention, the articular surface of the artificial knee joint bearing element with a reverse inclination according to the present invention has the lowest point that is most depressed downward on the anteroposterior cross section, and the vertical distance from the articular surface surface to the lower inclined surface is the most. A short first low point is defined, and the first low point is formed ahead of the lowest point.

According to another embodiment of the present invention, the front outer peripheral surface and the rear outer peripheral surface of the artificial knee joint bearing element with a reverse inclination according to the present invention are characterized in that they extend up and down at a predetermined angle so as to be perpendicular to the inclined surface.

According to another embodiment of the present invention, the bearing body and the inclined portion of the artificial knee joint bearing element with a reverse inclination according to the present invention are formed integrally.

The present invention can achieve the following effects by combining the above-mentioned embodiment with the configuration, combination, and use relationship described below.

The present invention relates to a bearing body having a curved shape and an articular surface indented downward so that the femoral element of an artificial knee joint can slide on the articular surface, the bearing body extending downward from the bearing body to contact the tibial element, The overall slope of the artificial knee joint system, including the inclined portion formed to slope to at least one side, is maintained gently, but the tibia is cut along the patient's unique tibial slope to avoid excessive fracture removal. It has the effect of providing bearing elements for artificial knee joints.

In the present invention, the inclined portion extends downward from the bearing body from the front to the rear, thereby reducing complications such as subsiding the replacement after artificial knee joint replacement surgery and pain while walking and improving the durability of the artificial knee joint insert.

In the present invention, the inclined portion includes an inclined surface extending backward with a constant inclination, an outer circumferential surface extending up and down along the circumference of the bearing body, and a connection surface formed between the inclined surface to tilt the load transmitted from the femoral element. It has the effect of stably delivering to the cut tibia.

The present invention provides an additional extension angle so that the knee can be better straightened after artificial joint surgery for patients with flexion contractures in which the knee cannot be fully straightened even in artificial knee joint procedures that form a tibial cutting surface using the existing method. It can have the effect of providing an artificial knee joint bearing element with an inclination.

In the present invention, at least a portion of the connecting surface is bent and extended from one end of the outer peripheral surface toward the center, and at least a portion of the connecting surface extends at a different inclination from the outer peripheral surface, so that a bearing element of a relatively large size can be seated even on a narrow tibial cutting surface. You can.

In the present invention, the outer peripheral surface includes a front outer peripheral surface forming the perimeter of the bearing body at the front of the bearing body and a rear outer peripheral surface forming the perimeter of the bearing body at the rear of the bearing body, and a connection surface with the rear outer peripheral surface at the rear end. It is possible to provide an artificial knee joint bearing element with a reverse inclination, wherein the extended vertical length is longer than the vertical length along which the front outer circumferential surface extends at the front end.

In the present invention, the articular surface is defined as the lowest point that is most depressed downward on the anteroposterior cross section, and the first low point with the shortest vertical distance from the articular surface surface to the lower slope, and the first low point is located anterior to the lowest point. This has the effect of improving durability from loads in the vertical direction.

In the present invention, the front outer peripheral surface and the rear outer peripheral surface extend vertically from the lower surface of the bearing body, and the inclined surface extends rearward with a predetermined inclination with respect to the lower surface of the bearing body, so that the tibial cutting surface is formed as a bearing element. The effect can be achieved by extending in the direction of the anatomical axis of the tibia.

According to the present invention, when the tibia is excised between 0 and 5 degrees in the conventional manner and the knee is not completely straightened (if flexion contracture remains) when the existing bearing is inserted, an additional extension angle can be obtained by using this bearing. . This is an effect due to the design of the bearing element being relatively thicker at the rear than at the front.

Figure 1 is a diagram showing a conventional artificial knee joint.
Figure 2 is a schematic view of the femur and tibia of a patient before artificial knee replacement surgery.
Figure 3 is a perspective view of an artificial knee joint bearing element 1 with a reverse slope according to a preferred embodiment of the present invention.
Figure 4 is a cross-sectional view taken along AA' of the artificial knee joint bearing element 1 with a reverse inclination according to an embodiment of the present invention.
Figure 5 is a front view of the artificial knee joint bearing element 1 having a reverse inclination and the femoral element 91 provided on the upper side of the bearing element according to an embodiment of the present invention.
Figure 6 is a view showing that the artificial knee joint bearing element 1 with a reverse inclination is seated on the tibia T together with the tibial element 93 according to an embodiment of the present invention.
Figure 7 is a cross-sectional view of an artificial knee joint bearing element 1 with a reverse slope according to another embodiment of the present invention.
Figure 8 is a diagram expressing the cutting angle of the tibia when the artificial knee joint bearing element 1 with a reverse inclination according to a preferred embodiment of the present invention is applied.
Figure 9 is a cross-sectional view of an artificial knee joint bearing element 1 with a reverse inclination according to another embodiment of the present invention.

Hereinafter, preferred embodiments of the artificial knee joint bearing element with a reverse inclination according to the present invention will be described in detail with reference to the attached drawings. In the following description of the present invention, if a detailed description of a known function or configuration is judged to unnecessarily obscure the gist of the present invention, the detailed description will be omitted. Unless otherwise specified, all terms in this specification have the same general meaning as understood by a person skilled in the art to which the present invention pertains, and if there is a conflict with the meaning of the terms used in this specification, this specification Follow the definitions used in the specification.

Throughout the specification, when a part "includes" a certain component, this does not mean excluding other components unless specifically stated to the contrary, but also means that other components may also be included. Terms such as “~unit” described mean a unit that processes at least one function or operation. In addition, when certain components are said to be "connected," this is not limited to the components being directly contacted and fastened to each other, but also includes being connected through other components, and even if not connected, a certain amount of force or energy can be transmitted. It may mean that it is arranged so that Hereinafter, the present invention will be described in detail by explaining preferred embodiments of the present invention with reference to the accompanying drawings.

Since the present invention is inserted into a human knee joint and is provided to reproduce the movement of the knee joint, the anterior, posterior, medial, lateral, and proximal as shown in FIG. 3 , the distal direction is defined, and with reference to this, the artificial knee joint bearing element (1) with a reverse inclination according to the present invention will be described. The proximal and distal sides can be described as superior and inferior.

Figure 3 is a perspective view of an artificial knee joint bearing element 1 with a reverse inclination according to a preferred embodiment of the present invention. The artificial knee joint bearing element (1) with the reverse slope maintains the slope of the overall joint surface of the artificial knee joint system gently as in the conventional invention, but cuts the tibia according to the patient's unique tibial slope to prevent excessive fracture. It is characterized by reducing complications and aftereffects after artificial knee joint replacement surgery and improving the durability of artificial knee joint implants by avoiding them. The artificial knee joint bearing element 1 may be seated or fixed on the tibia by combining with a tibial element 93, which will be described later, inserted into the tibia. The artificial knee joint bearing element 1 with a reverse inclination includes a bearing body 10, a post 30, and an inclined portion 50.

Figure 4 is a cross-sectional view taken along line A-A' of the inner portion of the artificial knee joint bearing element 1 with a reverse inclination according to an embodiment of the present invention. Referring to Figures 3 and 4, the bearing body 10 is provided so that the artificial knee joint femoral element can slide on the bearing body 10. The bending movement of the knee joint can be reproduced as the condyle of the femoral element moves in contact with the bearing body 10. As can be seen in FIG. 4, the bearing body 10 can be distinguished from the inclined portion 50, which will be described later, by using a horizontal surface H extending front and rear, that is, a surface parallel to the ground, as a boundary. The bearing body 10 may have a planar shape similar to that of the tibia and may be formed to have different heights for each section. The front portion of the bearing body 10 may be formed to be higher than the rear portion, which will be described later. The bearing body 10 includes an articulating surface 11 and an outer peripheral surface 13.

The articular surface 11 is configured to contact the femoral element and the condyle on the upper surface, that is, the proximal side, of the bearing body 10 so that the femoral element can reproduce the joint movement on the articular surface 11. The articular surface 11 may have a curved shape and be recessed downward to have a concave shape. As can be seen in Figure 5, the femoral element 91 is divided into medial and lateral parts and has a condyle 911 that protrudes convexly in the downward direction. It is in contact with the articular surface 11 to enable joint movement, so that the femoral element 91 can rotate and slide on the articular surface 11. The sliding movement refers to the sliding of the femoral element 91 toward the anterior or posterior direction on the articular surface 11. The meaning of sliding is not to be interpreted as limited to the translational movement of the femoral element 91, and the translational movement and It is desirable to interpret it also including that a certain rotational movement may be accompanied. In addition, in order to vary the rate at which rotation and sliding movements occur, the shape of the articular surface 11, which will be described later, may be formed asymmetrically on the inside and outside.

The curvature of the articular surface 11 may be formed not to correspond to the curvature of the condyle 911 of the femoral element, which controls the rate at which the femoral element 91 rotates and slides on the articular surface 11. This is to reproduce the actual knee bending and extension.

Referring again to FIG. 4, in order to reproduce natural knee movement and prevent dislocation, the bearing body 10 is formed so that the anterior portion of the joint surface 11 is higher than the posterior portion to a certain degree when moving from the front to the rear. It may have a posterior slope that slopes downward. However, as the articular surface 11 is formed to have a concave shape, it may have a shape that rises from the front to the rear in a certain section. In detail, the articular surface may be formed in a form that rises backwards from the lowest point 111, which will be described later, to the rear end of the articular surface 11. In FIG. 3, the articular surface 11 is formed to have a concave shape on the inner and outer sides, but in another embodiment of the present invention, sliding movement occurs predominantly in the lateral portion of the knee joint, and the medial portion In this case, a medial pivot can be implemented by allowing rotational movement to dominate, and in this case, the outer articular surface can be formed to be relatively flat compared to the inner side. The articular surface 11 includes a lowest point 111 and a first low point 113.

Referring to FIG. 6, the lowest point 111 refers to the lowest point among the joint surfaces when the articular surface 11 of the bearing body 10 is cut into a cross section extending anteriorly and posteriorly, and in the articular surface 11 It is used to refer to the lowest point among the parts indented to the bottom. The lowest point is a point defined on a cross section extending front and rear, and when the bearing element is viewed from a cross section other than the A-A' cross section, the position of the lowest point may vary to a certain extent forward or backward. As shown in FIG. 3, the degree of indentation and curvature of the articular surface 11 are different from the inner to the outer side of the bearing element 1, so the lowest point is the innermost or most distal part of the entire articular surface 11. It may mean a specific point on the outside, but it is preferable to view it as the lowest point on a cross-section that extends anteriorly and posteriorly, such as the A-A' cross-section. The lowest point 111 may have a first length t1, which is the vertical distance or vertical distance from the proximal side to the distal side of the inclined surface 51, which will be described later, that is, the distance along the mechanical and/or anatomical axis of the tibia. . Details regarding this will be described later in comparison with the first low point (113).

The first low point 113 may be defined as the point where the vertical distance from the articular surface to the lower inclined surface is the shortest. The first low point 113 is a point defined on a cross section extending front and rear, and when the bearing element is viewed from a cross section other than the A-A' cross section, the position of the first low point may vary to a certain extent forward or backward. there is.

As the bearing element 1 replaces a person's knee joint, a load is applied, and wear or breakage may occur as a result. The Korea Food and Drug Safety Evaluation Institute and others measure the durability of implants through wear tests and define the minimum thickness of artificial knee joints. As shown in FIG. 6, the first low point 113 is defined as the point where the vertical distance to the lower slope is the shortest, and is formed to have a thickness greater than a predetermined standard. The first low point 113 has a second distance t2, which is the vertical distance or vertical distance from the proximal side to the distal side with the inclined surface 51 described later, that is, the distance along the mechanical axis and/or anatomical axis of the tibia. You can.

The first low point 113 may be formed ahead of the lowest point 111. The lowest point 111 on the articular surface 11 is the most indented, but as the inclined surface 51 has a constant inclination and extends distally or downward from the front to the rear, the slope of the articular surface 11 becomes gentler. The point with the shortest vertical distance to the slope can be defined. At this time, in a loading environment where the load acts in the vertical direction, that is, in the anatomical axis direction of the tibia, the load due to the load is applied most to the lowest point (111). In the present invention, the first low point 113 is located ahead of the lowest point 111, so that the first distance t1 from the lowest point 111 to the lower and/or distal slope 51 is the first low point 113. ) by making it larger than the second distance (t2), which is the vertical distance from the inclined surface 51, so that the thickness of the part where wear occurs the most is the same as that of a conventional implant, while the thickness of the front part can be made thinner than before. Even with a thinner thickness, safety and durability against load can be maintained.

The outer peripheral surface 13 is provided to extend up and down along the circumference of the bearing body 10. As shown in FIGS. 3 to 6, the outer peripheral surface 13 has a curved shape and surrounds the side surface of the bearing body 10. The outer peripheral surface 13 may be formed to extend in a streamlined manner around the front, side, and rear portions of the bearing body 10. The length along which the outer peripheral surface 13 extends vertically may vary to a certain extent for each part. When looking at the bearing element 1 shown in FIG. 5 from the front side, the front end of the bearing body 10 may protrude convexly upward, so the outer peripheral surface 13 on the front side may extend higher than other parts. . In addition, as shown in FIG. 4, when the bearing body 10 has an overall shape in which the front side is higher than the rear side, the outer peripheral surface of the rear side may extend lower than the outer peripheral surface of the front side. The outer peripheral surface 13 includes a front outer peripheral surface 131, a side outer peripheral surface 133, and a rear outer peripheral surface 135. In a preferred embodiment of the present invention, the outer peripheral surface 13 may extend vertically along the anatomical axis of the tibia, but as in other embodiments of the present invention, it may extend at a predetermined angle with the anatomical axis of the tibia. It is not excluded from the scope.

The front outer peripheral surface 131 is a part that constitutes the circumference of the bearing body at the front of the bearing body and extends up and down with a predetermined length. The front outer peripheral surface 131 may extend vertically parallel to the anatomical axis of the tibia (T), as in the preferred embodiment of the present invention shown in FIG. 6, and in another embodiment of the present invention shown in FIG. 7. As in the example, it may extend up and down at a predetermined angle with the anatomical axis of the tibia (T). With respect to the front outer peripheral surface 131, a first vertical length h1 of the front outer peripheral surface 131 along the anatomical axis direction of the tibia may be defined. The length in which the front outer peripheral surface 131 extends vertically changes as it goes from the inside to the outside of the bearing element 1, and the first vertical length h1 is the position of the front and rear cross sections of the bearing element 1. It may vary depending on.

The lateral outer peripheral surface 133 extends upward and downward on the side of the bearing body 10, constituting the circumference of the bearing body. The lateral peripheral surface 133 extends while forming a curved surface on the inside and outside of the bearing body, and its extension length may vary depending on the location. The side outer peripheral surface 133 may be provided on the side of the bearing body 10 to connect the front outer peripheral surface 131 and the rear outer peripheral surface 135, which will be described later.

The rear outer peripheral surface 135 extends up and down at the rear of the bearing body 10 and forms the circumference of the bearing body. The rear outer peripheral surface 135 may extend vertically parallel to the anatomical axis of the tibia (T), and may be aligned with the anatomical axis of the tibia (T) as in another embodiment of the present invention shown in FIG. 7. It can extend up and down with an angle of . Since the rear height of the bearing body 10 may vary as it moves from the inside to the outside of the bearing element 1, the length that the rear outer peripheral surface 135 extends vertically is determined by the position of the front and rear cross sections of the bearing element 1. It may vary depending on

The lower surface 15 is a part that constitutes the distal plane of the bearing body 10 along the horizontal surface H extending forward and backward, and is a surface that serves as a reference for the direction in which the outer peripheral surface 13 extends. In a preferred embodiment of the present invention, the outer peripheral surface 13 may extend vertically up and down from the lower surface 15. The lower surface may be provided or defined to be substantially parallel to the horizontal surface (H). It may be substantially the same as the upper surface of the inclined portion 50. As the bearing body 10 and the inclined portion 50 are provided as one body, the lower surface 15 may not be exposed to the outside or may be omitted.

In another embodiment of the present invention shown in Figure 7, the front outer peripheral surface 131 and/or the rear outer peripheral surface 135 extends up and down at a predetermined angle with the anatomical axis of the tibia (T) in a horizontal plane. It can also be defined as extending from (H) at a predetermined angle rather than a right angle. At this time, the inclined surface 51, which will be described later, has a predetermined inclination α with respect to the horizontal surface (H), and the front outer peripheral surface 131 and/or the rear outer peripheral surface 135 may extend while preferably forming a right angle to the inclined surface. . At this time, the joint surface 111 and the post 30 may be positioned relatively rearward.

Referring again to FIGS. 3 to 6, the post 30 replaces the posterior cruciate ligament to prevent posterior dislocation when the artificial knee joint is bent, and can be provided for natural knee movement (femoral roll back phenomenon). The post 30 protrudes upward or proximally from the bearing body 10 and engages with the femoral element 91 to reproduce knee movement through post-cam movement. Similarly, in types such as AS (anterior stabilized) or UC (ultra congruence), which do not have a post while removing the posterior cruciate ligament, in another embodiment of the present invention, the bearing body (10) is provided without the post (30). ) and an inclined portion 50 to be described later may be provided to reproduce the knee movement of the artificial knee joint.

The inclined portion 50 is configured to extend downward from the bearing body 10 and be in contact with the tibial element, and is formed to extend downward from the bearing body on at least one side, preferably from the front to the rear. The slope corresponding to may have a forward slope. The inclined portion 50 may be distinguished from the bearing body 10 by a horizontal surface H extending forward and backward, that is, a plane parallel to the ground, but preferably extends integrally from the bearing body 10. can be formed. As the inclined portion 50 is provided with a predetermined inclination on the lower side of the bearing body 10, the surgeon can cut the patient's tibia in a direction parallel to the ground or close to perpendicular to the anatomical axis of the tibia. The cutting surface of the tibia can be resected to have an inclination close to the posterior inclination of the patient's tibia, allowing less cutting of the anterior portion. In addition, it is possible to form a tibial cutting surface by cutting relatively less of the anterior cortical bone (CoT) portion, which was excessively cut, thereby improving the stability and durability of the knee joint after surgery. In particular, in the case of the Asian population with a posterior tilt of more than 10 degrees, preferably about 14 degrees, it is possible to reproduce the patient's unique knee joint. The inclined portion 50 includes an inclined surface 51 and a connecting surface 53.

)를 가지면서 연장될 수 있다. 본 발명의 바람직한 일 실시예에서는 상기 경사면(51)이 일정한 경사도를 가지면서 전방으로 경사져 형성될 수 있고, 상기 경사도()는 3도 내지 7도일 수 있다. 여기서, '전방경사'란 상기 경사면(51)이 전방으로 갈수록 상측 또는 근위측으로 올라오는 형상으로 정의되는 것으로, 경골의 절삭면이 후방으로 갈수록 하측 또는 원위측으로 내려가는 형상을 가지는 '후방경사'와 대응되는 개념으로 사용될 수 있다. 상기 경사도()는 바람직하게는 전단에서의 전방외주면(131)이 연장되는 수직길이(h1)보다 베어링요소 후단에서의 후방외주면(135)과 연결면(53)이 연장되는 수직길이(h2)가 더 길도록 그 수치가 제한될 수 있다(h2>h1). 그러나, 하면의 경사도()가 작게 형성되어 후술하는 연결면(53)의 길이가 작은 경우, 따라 전단에서의 수직길이(h1)가 후단에서의 수직길이(h2)보다 길도록 형성될 수도 있다(h1>h2). 도 5를 참고하면, 상기 경사면(51)은 상기 경사면을 전후방으로 연장되는 수평면(H)에 대해 정사영하는 경우 베어링바디(10)와 같은 평면을 가질 수 있다. The inclined surface 51 may have an anterior inclination and extend to contact the tibial element. As can be seen in Figures 4 and 6, the inclined surface has a predetermined slope (

) can be extended by having. In a preferred embodiment of the present invention, the inclined surface 51 may be formed to be inclined forward with a constant inclination, and the inclination ( ) may be 3 to 7 degrees. Here, the 'anterior slope' is defined as a shape in which the inclined surface 51 rises toward the upper or proximal side as it moves forward, and corresponds to the 'posterior slope' in which the cutting surface of the tibia has a shape that goes downward or distally toward the rear. It can be used as a concept. The slope ( ) is preferably such that the vertical length (h2) over which the rear outer peripheral surface 135 and the connecting surface 53 at the rear end of the bearing element extend is longer than the vertical length h1 over which the front outer peripheral surface 131 at the front end extends. That number may be limited (h2>h1). However, the slope of the bottom ( ) is formed small and the length of the connection surface 53 described later is small, the vertical length (h1) at the front end may be formed to be longer than the vertical length (h2) at the rear end (h1>h2). Referring to FIG. 5, the inclined surface 51 may have the same plane as the bearing body 10 when the inclined surface 51 is orthogonally projected on a horizontal surface H extending forward and backward.

Referring to Figure 8, when applying the bearing element according to an embodiment of the present invention, the inclined surface 51 is provided so that when cutting the tibia, the cutting surface descends toward the distal side toward the rear, that is, has a posterior inclination. can be formed. Unlike the conventional cutting surface that is cut to form an angle parallel to the ground or a posterior inclination of less than about 3 degrees from the ground, the cutting angle (β) of the tibia cutting surface is increased by the inclination (α) of the inclined surface (51) to the horizontal plane (H). ) can be 3 to 12 degrees. Furthermore, C shown as a dotted line in FIG. 8 corresponds to the cutting surface of the tibia when using the existing bearing element, and it can be seen that as the inclined surface 51 is provided, less of the front part of the tibia is cut. Accordingly, when the inclined surface 51 is placed parallel to the ground, the joint surface 11 is formed due to the overall shape of the artificial knee joint bearing element with a reverse slope according to the present invention in which the front part is thin and the rear part is relatively thick. The upper surface may have a forward slope.

In addition, the inclination of the inclined surface 51 ( ) has an anterior tilt of 3 to 7 degrees, providing additional extension interval so that patients with flexion contractures that do not fully straighten their knees can straighten their knees better after artificial joint replacement. Because the bearing element according to the present invention has a shape in which the front part is relatively thinner than the rear part, the extension gap is widened when the knee is straightened, and this additionally provides space for the knee to spread further, enabling normal knee movement. do.

The connection surface 53 is formed between the outer peripheral surface 13 extending up and down along the circumference of the bearing body 10 and the inclined surface 51, and may be provided to connect the outer peripheral surface 13 and the inclined surface 51. . The connection surface 53 may preferably be formed between the lateral connection surface 133 and/or the rear connection surface 135 and the inclined surface 51. In a preferred embodiment of the present invention, the connection surface 53 may extend along the outer peripheral surface at the same inclination as the outer peripheral surface. As shown in FIG. 6, when the rear outer peripheral surface 135 extends substantially vertically while forming a right angle to the horizontal surface (H), the connection surface 53 is tilted from the rear outer peripheral surface 135 at the same inclination as the rear outer peripheral surface 135. It may be extended and connected to the inclined surface 51. In another embodiment of the present invention, as shown in FIG. 9, at least a portion of the connecting surface 53 is bent and extended from one end of the outer peripheral surface toward the center, thereby extending at a different inclination from the outer peripheral surface 13 and connected to the inclined surface 51. . In this case, a relatively large bearing element can be brought into contact with the narrow tibial cutting surface and the tibial element, making it possible to perform artificial knee joint replacement surgery suitable for patients who require a bearing element (1) larger than the tibial cutting surface.

As can be seen in Figure 6, the rear outer peripheral surface 135 and the connection surface 53 may have a second vertical length (h2) defined according to the anatomical axis direction of the tibia. The length in which the rear outer peripheral surface 135 and the connecting surface 53 extend vertically varies from the inside to the outside of the bearing element 1, and the second vertical length h2 is the bearing element 1. ) may vary depending on the location of the anteroposterior cross section.

At this time, the second vertical length (h2) may be longer than the first vertical length (h1). In the bearing element 1 according to the present invention, the bearing body 10 has an overall shape in which the front is higher than the rear, but as the connection surface 53 extends from the rear, a connection surface 53 is formed on the lower side of the rear outer peripheral surface 135. ) is provided so that the second vertical length (h2) extending vertically between the rear outer peripheral surface 135 and the connecting surface 53 is longer than the first vertical length (h1) extending vertically of the front outer peripheral surface 131. . In Figure 6, the vertical length (h2) extending between the rear outer circumferential surface and the connection surface with respect to the A-A' cross section on the medial side of the front outer circumferential surface is provided to be longer than the vertical length (h1) through which the front outer circumferential surface extends. This is preferably the case not only on the inside but also on the outside of the bearing element 1. In another embodiment of the present invention, when the inclination of the inclined surface 51 is small and the extending length of the connecting surface 53 is short, the front outer peripheral surface 131 is formed due to a shape in which the front of the bearing body 10 is higher than the rear as a whole. The first vertical length h1 extending up and down may be formed to be longer than the second vertical length h2 extending up and down between the rear outer peripheral surface 135 and the connection surface 53.

The artificial knee joint bearing element 1 of the present invention can be combined with a tibial element 93 that is inserted into the tibia after cutting the tibia. Preferably, the inclined surface 51 of the artificial knee joint bearing element 1 is coupled to the tibial element 93. As the inclined surface 51 is formed with a forward slope, the tibial element also moves downward from the front to the rear, that is, It can be formed with a slope going down to the distal side. The tibial element 93 may have an inner wall with a predetermined thickness extending from the outer peripheral surface to the upper or proximal side, and the inner wall and the lower surface of the inclined portion 50 may be coupled through a taper coupling, interference fit coupling, etc. At this time, the inner wall extending proximally from the tibial element 93 may be formed to extend at a shape and angle corresponding to the shape of the outer peripheral surface 13 and the connection surface 53 of the artificial knee joint bearing element 1.

The above detailed description is illustrative of the present invention. Additionally, the foregoing is intended to illustrate preferred embodiments of the present invention, and the present invention can be used in various other combinations, modifications, and environments. That is, changes or modifications can be made within the scope of the inventive concept disclosed in this specification, a scope equivalent to the written disclosure, and/or within the scope of technology or knowledge in the art. The written examples illustrate the best state for implementing the technical idea of the present invention, and various changes required for specific application fields and uses of the present invention are also possible. Accordingly, the detailed description of the invention above is not intended to limit the invention to the disclosed embodiments. Additionally, the appended claims should be construed to include other embodiments as well.

1: Artificial knee joint bearing element with reverse inclination
10: bearing body 11: joint surface
111: Lowest point 113: First low point
13: outer peripheral surface 131: front outer peripheral surface
133: Lateral outer peripheral surface 135: Rear outer peripheral surface
15: If you do
30: Post 50: Inclined portion
51: slope 53: connection surface

Claims (11)

In artificial knee joint implants,
A bearing body having a curved shape on the inside and outside and an articular surface indented downward so that the artificial knee joint femoral element can slide on the articular surface, extending downward from the bearing body to contact the tibial element, It includes an inclined portion extending downward from the bearing body from the front to the rear,
The inclined portion includes an inclined surface extending with a constant inclination relative to a horizontal plane extending front and rear from the bearing body,
The inclined surface is an artificial knee joint bearing element with a reverse inclination, characterized in that it forms an incline that rises toward the upper or proximal side as it moves forward. delete The method of claim 1, wherein the inclined portion is:
An artificial knee joint bearing element with a reverse inclination, further comprising a connection surface formed between the inclined surface and an outer peripheral surface extending up and down along the circumference of the bearing body. The artificial knee joint bearing element according to claim 3, wherein the connection surface extends along the outer peripheral surface at the same inclination as the outer peripheral surface. The artificial knee joint bearing element according to claim 3, wherein at least a portion of the connection surface is bent and extended from one end of the outer peripheral surface toward the center, so that at least a portion of the connecting surface extends at an inclination different from that of the outer peripheral surface. The artificial knee joint bearing element according to claim 1, wherein the inclination of the inclined surface is 3 degrees or more and 7 degrees or less. The method according to any one of claims 3 to 6, wherein the outer peripheral surface includes a front outer peripheral surface forming the perimeter of the bearing body at the front of the bearing body and a rear outer peripheral surface forming the perimeter of the bearing body at the rear of the bearing body. ,
An artificial knee joint bearing element with a reverse inclination, characterized in that the vertical length over which the rear outer peripheral surface and the connecting surface extend at the rear end are longer than the vertical length over which the anterior outer peripheral surface extends at the front end. The method of claim 7, wherein the articular surface is defined as the lowest point that is most indented downward on the anteroposterior cross section, and the first low point where the vertical distance from the articular surface surface to the lower slope is the shortest,
The first low point is an artificial knee joint bearing element with a reverse slope, characterized in that it is formed on a front side of the lowest point. The method of claim 7, wherein the front outer peripheral surface and the rear outer peripheral surface extend vertically from the lower surface of the bearing body, and the inclined surface extends rearward with a predetermined inclination with respect to the lower surface of the bearing body. Artificial knee joint bearing elements. The artificial knee joint bearing element according to claim 7, wherein the front outer peripheral surface and the rear outer peripheral surface extend upward and downward at a predetermined angle so as to be perpendicular to the inclined surface. The artificial knee joint bearing element according to claim 1, wherein the bearing body and the inclined portion are formed integrally.

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