WO2018030716A1

WO2018030716A1 - Head for artificial joint and artificial joint including same

Info

Publication number: WO2018030716A1
Application number: PCT/KR2017/008441
Authority: WO
Inventors: 전인호; 홍한표
Original assignee: 재단법인 아산사회복지재단
Priority date: 2016-08-08
Filing date: 2017-08-04
Publication date: 2018-02-15
Also published as: KR20180016893A

Abstract

The present invention provides an artificial joint comprising: a stem fixed at one end thereof to a first bone of a human body and having a coupling part at the other end thereof; a head comprising an insertion part in which the coupling part is inserted; and an acetabular cup having a reception part formed therein to allow the head to be inserted and rotate and being fixed to a second bone corresponding to the first bone, wherein the head comprises a first concave part formed to be recessed by a predetermined depth toward the center of the head from the outer peripheral surface of the head.

Description

Head for artificial joint and artificial joint comprising same

The present invention relates to an artificial joint head and an artificial joint including the same.

The hip joint is a joint that connects between the femur of the human body and the acetabular pelvis, and is a joint that plays an important role in sitting or standing. The hip can be damaged by pathological causes such as arthritis and femoral head avascular necrosis and trauma. If the damage is large, the artificial hip can be inserted through surgery to replace it.

An artificial hip is a surgical implant that replaces an injured hip (hip) with an artificial joint. It consists of an acetabular cup, a head, and a stem. The acetabular cup, head and stem are made of materials such as titanium alloy, which are harmless to the human body. The acetabular cup is located in the acetabular pelvis, and the stem is inserted into the femur and fixed. In addition, a spherical head formed of a ceramic or metal material is fixed to the end of the stem, and the head is accommodated in the acetabular cup to rotate.

The head is rotated while being accommodated in the acetabular cup, where the acetabular cup and the head make point contact. Although the joint fluid is received between the acetabular cup and the head, continuous rotation of the head causes the joint fluid to be pushed out, reducing the cushioning function between the acetabular cup and the head, resulting in head wear.

In order to solve the above problems and / or limitations, the present invention has an object to provide an artificial joint head and an artificial joint including the same that can minimize the wear between the acetabular cup and the head of the artificial joint.

One embodiment of the present invention, one end is fixed to the first bone of the human body, the other end of the stem (stem) formed with a coupling portion, the head including an insertion portion is inserted into the coupling portion and the head is inserted can be rotated An accommodating cup formed to accommodate the second bone, wherein the second bone corresponds to the first bone, and the head is recessed to a predetermined depth from the outer circumferential surface of the head toward the center of the head. An artificial joint is provided, comprising a recess.

The artificial joint of the present invention may minimize the wear by maximizing the hydraulic lubricating action between the head and the acetabular cup through the head for artificial joint including the first recess. In addition, the artificial joint of the present invention allows the head and the acetabular cup to be in circular contact instead of point contact through the first concave having a smooth curved surface, so that the artificial joint can withstand external shocks. Can be improved.

1 is a perspective view schematically showing an artificial joint according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along the line II-II of FIG. 1.

FIG. 3 is a conceptual view schematically illustrating the artificial joint head of FIG. 1.

4 is a perspective view schematically showing an artificial joint according to another embodiment of the present invention.

The present invention has one end fixed to the first bone of the human body, a stem having a coupling portion formed at the other end, a head including an insertion portion into which the coupling portion is inserted, and a receiving portion formed so that the head can be inserted and rotated. And an acetabular cup fixed to a second bone, wherein the second bone corresponds to the first bone, and the head includes a first recess formed to be recessed to a certain depth from the outer circumferential surface of the head toward the center of the head. To provide artificial joints.

In one embodiment of the present invention, the first concave portion may be disposed on an extension line extending in the longitudinal direction of the insertion portion.

In one embodiment of the present invention, the first concave portion is a first curved surface disposed in the center of the first concave portion, the first curved surface and the outer peripheral surface of the head while circumferentially the edge of the first curved surface It may include a second curved surface connecting the.

In one embodiment of the present invention, the first curved surface may have a concave shape in the direction of the center of the head, and the second curved surface may have a convex shape toward the acetabular cup.

In one embodiment of the present invention, the first curved surface has a first radius of curvature centered on the outside of the head, the second curved surface has a second radius of curvature located in the center of the head Can have

In one embodiment of the present invention, the second radius of curvature may be equal to 1/2 of the radius of the head.

In one embodiment of the present invention, the head may be spaced apart from each other on the outer circumferential surface of the head, and may further include a plurality of second recesses formed in the same shape as the first recess.

The present invention, in a state in which one end is coupled to the other end of the stem (stem) fixed to the first bone of the human body, is accommodated in the acetabular cup fixed to the second bone corresponding to the first bone in the rotatable head (head) The head may include an insertion part into which a coupling part formed at the other end of the stem is inserted; And a first recess formed to be recessed to a predetermined depth from the outer circumferential surface of the head toward the center of the head.

In one embodiment of the present invention, the first concave portion may be disposed on an extension line extending along the longitudinal direction of the insertion hole.

Other aspects, features, and advantages other than those described above will become apparent from the following drawings, claims, and detailed description of the invention.

Hereinafter, the following embodiments will be described in detail with reference to the accompanying drawings, and the same or corresponding components will be denoted by the same reference numerals, and redundant description thereof will be omitted.

The embodiments are capable of various transformations, and specific embodiments will be illustrated in the drawings and described in detail in the written description. Effects and features of the embodiments and a method of achieving them will be apparent with reference to the following description in detail in conjunction with the drawings. However, the present embodiments are not limited to the embodiments disclosed below but may be implemented in various forms.

In the following embodiments, the terms "first" and "second" are used for the purpose of distinguishing one component from other components rather than a restrictive meaning.

In the following examples, the singular forms “a”, “an” and “the” include plural forms unless the context clearly indicates otherwise.

In the following embodiments, the term "include" or "having" means that a feature or component described in the specification is present and does not preclude the possibility of adding one or more other features or components.

In the following embodiments, when a part such as a unit, an area, a component, or the like is located on or on another part, as well as being directly above another part, other units, areas, components, etc. are interposed therebetween. It also includes the case.

In the following embodiments, the terms connect or combine, and the like, do not necessarily mean direct and / or fixed connection or coupling of two members, unless the context clearly indicates otherwise. It is not excluded.

It means that there is a feature or component described in the specification and does not preclude the possibility of adding one or more other features or components.

In the drawings, components may be exaggerated or reduced in size for convenience of description. For example, the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of description, and therefore the following embodiments are not necessarily limited to those shown.

Hereinafter, an artificial joint 10 according to an embodiment of the present invention will be described with reference to the drawings.

1 is a perspective view schematically showing the artificial joint 10 according to an embodiment of the present invention, Figure 2 is a cross-sectional view taken along the line II-II of Figure 1, Figure 3 for the artificial joint of Figure 1 A conceptual diagram schematically illustrated for describing the head 200.

Referring to FIG. 1, an artificial joint 10 according to an embodiment of the present invention may include a stem 100, a head 200, and an acetabular cup 300.

One end of the stem 100 is inserted into and fixed to the first bone of the human body, and a coupling part 110 may be formed at the other end. Specifically, although not shown, the first bone may be the femur. The stem 100 has a front end portion 130 inserted into the femur, a seating portion 120 extending from the front end portion 130, and a coupling portion 110 which can be coupled to the head 200 which is extended from the seating portion 120 and described later. ) May be included. The distal end 130 and the seating part 120 are inserted into the femur and fixed to the femur by the bone marrow secreted from the femur. The tip portion 130 may have a circular cross-section in the longitudinal direction and may have a long rod shape, and may have a smaller diameter than the seating portion 120. The seating part 120 may be formed in an elliptical shape with respect to the longitudinal direction, and may be formed such that the area of the cross section is increased toward the coupling part 110. The coupling part 110 may form a predetermined angle with the seating part 120, and may be formed at an obtuse angle corresponding to the physical characteristics of the user.

The acetabular cup 300 is provided with a receiving portion 310 (see FIG. 2) so that the head 200 is inserted and rotated, and may be fixed to a second bone corresponding to the first bone. The second bone may be the pubic bone of the user connected to the femur, which is the first bone. The receiving part 310 may be formed in the shape of a hemispherical cup to accommodate the head 200 having a ball shape. Acetabular cup 300 may be coupled to the pubis through a protruding outer surface. The outer surface of the acetabular cup 300 may be made of a metal having biocompatibility, for example, titanium alloy. The accommodating part 310 of the acetabular cup 300 may be made of a material different from that of the outer surface, for example, made of a ceramic material. On the other hand, the acetabular cup 300 is not shown, the outer surface may be formed to be porous to promote bone fusion with the pubic bone. As another example, the acetabular cup 300 may be coupled to the pubis using a coupling means such as a screw.

On the other hand, the head 200 may be mounted to the stem 100 including an insertion portion 230 into which the coupling portion 110 of the stem 100 may be inserted. The head 200 has a first concave portion formed to be embedded in a predetermined depth from the outer circumferential surface of the head 200 toward the center O of the head 200 on an extension line A extending along the longitudinal direction of the insertion portion 230. And may include 210.

Referring to FIG. 2, the first recess 210 may include a first curved surface 211 and a second curved surface 213 having a curved shape. The first curved surface 211 is disposed in the center of the first concave portion 210 and may have a concave shape in the center direction of the head 200. The second curved surface 213 may connect the outer circumferential surface of the first curved surface 211 and the head 200 while circumscribing the edge of the first curved surface 211. The second curved surface 213 may have a convex shape toward the acetabular cup 300. In other words, the first concave portion 210 may be a recess recessed from the outer circumferential surface of the head 200 and may be close to the groove shape near the top of the apple, for example.

The first concave portion 210 may perform a substantial reservoir function of the joint fluid in a state where the head 200 is accommodated in the acetabular cup 300. The head according to the comparative example is formed into a perfect sphere. The joint fluid performs a lubrication function that reduces the friction between the head and the acetabular cup between the head and the acetabular cup. The spherical head according to the comparative example is accommodated in the acetabular cup and rotated while the joint fluid is pushed into the space between the head and the acetabular cup by rotation, and the friction between the acetabular cup and the head cannot be sufficiently reduced. In addition, since the spherical head is in point contact with the acetabular cup, there is a high risk of the head breaking when an impact is applied.

However, unlike this, the artificial head 200 according to the embodiment of the present invention includes a first recess 210 which is a reservoir of a joint fluid, and the joint fluid is always accumulated in the first recess 210. The hydrodynamic lubrication between the head 200 and the acetabular cup 300 may be continuously performed. Lubrication refers to a phenomenon in which a material such as a liquid or a solid is inserted between friction surfaces to reduce the interaction between the two surfaces. Hydraulic lubrication in artificial joints means using joint fluids to reduce friction between friction surfaces. In the comparative example, hydraulic lubrication through the joint fluid occurs, but as described above, sufficient fluid flow cannot be maintained. The head 200 for an artificial joint according to an embodiment of the present invention can sufficiently maintain the flow of the joint fluid by using the first concave portion 210, and has less friction between the head 200 and the acetabular cup 300. It is possible to reduce the wear of the head 200 or the acetabular cup 300. In addition, the first concave portion 210 allows the head 200 to induce a circular contact rather than a point contact with the acetabular cup 300, so that the impact structure is more robust than that of the comparative example. Can be formed. On the other hand, since the first concave portion 210 is disposed on an extension line in the longitudinal direction of the insertion portion 230 of the head 200, the first concave portion 210 also moves together by the rotation of the head 200. Can perform the function of.

Referring to FIG. 3, the first concave portion 210 may include the first curved surface 211 and the second curved surface 213 as described above. In this case, the first curved surface 211 has a first radius of curvature R1 at which the center O1 is located outside the head 200, and the second curved surface 213 is centered inside the head 200. It may have a second radius of curvature R2 where (O2) is located. In other words, the first curved surface 211 may have a concave shape toward the center of the head 200, and the second curved surface 213 may have a convex shape toward the acetabular cup 300. The first radius of curvature R1 and the second radius of curvature R2 may be the same, but the present invention is not limited thereto. In another embodiment, the first radius of curvature R1 may be smaller than the second radius of curvature R2. Meanwhile, the second radius of curvature R2 may be equal to 1/2 of the radius r of the head 200. The second radius of curvature R2 has a value of 1/2 of the radius r of the head 200, thereby forming a convex second curved surface 213 having a gentle slope from the outer circumferential surface of the head 200. Can be. Through this, the stored joint fluid of the first concave portion 210 can easily flow out on the second curved surface 213, and may further maximize the hydraulic lubrication effect.

Meanwhile, the size of the first concave portion 210 may correspond to the size D1 of the insertion portion 230 on the outer circumferential surface of the head 200. The size of the first concave portion 210 means the size at both ends that are embedded due to the circles having the second radius of curvature R2, which is substantially the same as the size D1 of the insert 230. can do. There is no limitation on the size of the first concave portion 210, but when the size of the first concave portion 210 is larger than the size (D1) of the insertion portion 230, the depth of the first concave portion 210 as well As it becomes larger, it may be weak to external shocks. In addition, when the size of the first concave portion 210 is smaller than the size (D1) of the insertion portion 230, it may not be sufficient to perform the joint fluid reservoir function between the head 200 and the acetabular cup (300).

While the first concave portion 210 stores the joint fluid in the first curved surface 211 concave through the above-described shape, the joint fluid is easily out of the first concave portion 210 through the second convex curved surface 213. Can be discharged. Therefore, the artificial joint 10 according to the embodiment of the present invention can induce continuous storage and flow of the joint fluid, and can maximize the hydraulic lubricating action to reduce wear.

4 is a perspective view schematically showing an artificial joint 10 according to another embodiment of the present invention.

Referring to FIG. 4, the artificial joint head 200 may include a first recess 210 and may further include a plurality of second recesses 250. The plurality of second recesses 250 may be spaced apart from each other on the outer circumferential surface of the head 200, and may be formed in the same shape as the first recesses 210. The size of the second recess 250 may be the same as or smaller than the first recess 210. The second recess 250 may be disposed at a position different from that of the first recess 210 to serve as a reservoir of joint fluid having the same function as the first recess 210. Although the second recess 250 is regularly arranged in the drawing, as another embodiment, the second recess 250 may be irregularly arranged. The position and number of the second recesses 250 may be designed so as not to affect the durability of the head 200.

As described above, the artificial joint 10 according to the embodiments of the present invention is provided between the head 200 and the acetabular cup 300 through the artificial joint head 200 including the first concave portion 210. Minimize wear by maximizing hydraulic lubrication. In addition, in the artificial joint 10 according to the embodiments of the present invention, the head 200 and the acetabular cup 300 are circular contact instead of point contact through the first concave having a smooth curved surface. By doing so, it is possible to improve the durability that the artificial joint 10 can withstand external shocks.

In the present specification, although the artificial joint has been described as an artificial joint disposed between the femur and the pubis, the present invention is not limited thereto and may be applied to artificial joints at other positions.

As described above, the present invention has been described with reference to one embodiment shown in the drawings, which is merely exemplary, and it will be understood by those skilled in the art that various modifications and embodiments may be made therefrom. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

According to the present invention, an artificial joint head and an artificial joint including the same are provided. In addition, embodiments of the present invention can be applied to artificial joint surgery used in the industry.

Claims

A stem, one end of which is fixed to the first bone of the human body and having a coupling part formed at the other end thereof;

A head including an insertion portion into which the coupling portion is inserted; And

Includes a receiving portion is formed so that the head can be rotated, the acetabular cup is fixed to the second bone;

The second bone corresponds to the first bone,

The head includes a first concave portion formed to be recessed to a certain depth from the outer peripheral surface of the head toward the center of the head.
According to claim 1,

The first recessed part is disposed on an extension line extending in the longitudinal direction of the insert, artificial joint.
According to claim 1,

The first recess includes a first curved surface disposed in the center of the first recessed portion, and a second curved surface connecting the first curved surface and the outer circumferential surface of the head while circumscribing an edge of the first curved surface. , Artificial joints.
The method of claim 3, wherein

The first curved surface is concave in the direction of the center of the head (concave),

And the second curved surface is convex in shape toward the acetabular cup.
The method of claim 3, wherein

The first curved surface has a first radius of curvature, the center of which is located outside the head,

And the second curved surface has a second radius of curvature centered within the head.
The method of claim 5,

And the second radius of curvature is equal to one half of the radius of the head.
According to claim 1,

The head is spaced apart from each other on the outer circumferential surface of the head, and further comprising a plurality of second recessed portion formed in the same shape as the first recessed portion, artificial joint.
In a state in which one end is coupled to the other end of the stem (stem) fixed to the first bone of the human body, in the rotatable head accommodated in the acetabular cup fixed to the second bone corresponding to the first bone,

The head is

An insertion portion into which a coupling portion formed at the other end of the stem is inserted; And

And a first recess formed in a predetermined depth from the outer circumferential surface of the head toward the center of the head.
The method of claim 8,

The first concave portion is disposed on the extension line extending in the longitudinal direction of the insertion portion, the artificial joint head.
The method of claim 8,

The first recess includes a first curved surface disposed in the center of the first recessed portion, and a second curved surface connecting the first curved surface and the outer circumferential surface of the head while circumscribing an edge of the first curved surface. Head for artificial joint.
The method of claim 10,

The first curved surface is concave in the direction of the center of the head (concave),

Wherein the second curved surface is convex toward the acetabular cup.
The method of claim 10,

The first curved surface has a first radius of curvature, the center of which is located outside the head,

And the second curved surface has a second radius of curvature centered within the head.
The method of claim 12,

And said second radius of curvature is equal to one-half of the radius of said head.
The method of claim 8,

The head is disposed on the outer circumferential surface of the head spaced apart from each other, further comprising a plurality of second recessed portion formed in the same shape as the first recessed portion, artificial head.