CN215019765U

CN215019765U - Acetabular cup

Info

Publication number: CN215019765U
Application number: CN202122495770.6U
Authority: CN
Inventors: 李新宇
Original assignee: Beijing AK Medical Co Ltd
Current assignee: Beijing AK Medical Co Ltd
Priority date: 2021-10-18
Filing date: 2021-10-18
Publication date: 2021-12-07
Anticipated expiration: 2031-10-18

Abstract

The utility model provides an acetabular cup. The acetabular cup includes: a cup body, the cup body includes an outer surface and an inner surface, the outer surface is a first spherical surface for connecting with the acetabular fossa, and the inner surface is a second spherical surface for connecting with the femoral head; Wherein, there is a distance between the center of the first spherical surface and the center of the second spherical surface, so that the thickness of the upper side of the outer surface cup body is greater than the thickness of the lower side of the cup body. The application of the technical solution of the utility model can solve the problem that the acetabular cup in the prior art is prone to fracture and failure due to stress concentration.

Description

Acetabular cup

Technical Field

The utility model relates to a prosthetic replacement technical field particularly, relates to an acetabular cup.

Background

The human skeleton is the main bearing structure of the human body and is very important for the human body. The acetabulum part is the core joint area of the physiological motion of the lower limbs of the human body. The defect or damage of the bone of the acetabulum part can cause serious influence on the normal life of people. Currently, a common way to treat hip joint problems caused by osteoarthritis or degenerative osteoarthritis is to perform a hip replacement surgery. The hip replacement surgery adopts ceramic acetabulum prosthesis to fill damaged acetabulum fossa to form an artificial joint interface with good friction performance.

Problems still exist in using ceramics as artificial acetabular prostheses. Although the toughness of the existing ceramic material is greatly improved compared with the existing ceramic product, the difference of the existing ceramic material from the bone of a human body is still large, and due to the physiological motion characteristics of the human body, the stress of the acetabulum is mainly concentrated on one side part of the upper edge of the acetabulum, and the stress of other parts is smaller. For a common acetabular cup, under the physiological condition, the stress distribution on the acetabular cup is extremely uneven, and when the stress of the acetabular cup is different, the stress on the cross section is in an uneven state. Under such a stress environment, the acetabular cup may deform locally. For conventional metal cup-polyethylene lined prostheses, this local deformation can result in severe regional wear and ultimately failure of the prosthesis. This uneven deformation is more severe for ceramic materials, which in turn can lead to fracture of the ceramic material and greater patient injury.

SUMMERY OF THE UTILITY MODEL

A primary object of the present invention is to provide an acetabular cup to solve the problem of failure of acetabular cup due to stress concentration.

In order to achieve the above object, the present invention provides an acetabular cup, including: the cup body comprises an outer surface and an inner surface, wherein the outer surface is a first spherical surface and is used for being connected with the acetabulum socket, and the inner surface is a second spherical surface and is used for being connected with a femoral head; and a distance is reserved between the spherical center of the first spherical surface and the spherical center of the second spherical surface, so that the thickness of the upper side of the outer surface cup body is larger than that of the lower side of the cup body.

Furthermore, the distance between the spherical center of the first spherical surface and the spherical center of the second spherical surface is D, wherein D is more than 0 and less than or equal to 2.5 mm.

Further, the center of the first spherical surface is located in a plane in which the end surface of the cup body is located.

Further, the center of the second spherical surface is located in the plane of the end surface of the cup body.

Further, the maximum thickness of the cup body is d1, the minimum thickness of the cup body is d2, wherein 1.2 < d1/d2 < 1.5.

Further, the bone integration layer is wrapped on the outer surface.

Further, the osseointegration layer is smaller than the cup thickness.

Further, the osseointegration layer is formed by spraying titanium and hydroxyapatite.

Furthermore, the cup body is made of ceramic materials and is formed in a cutting mode.

Furthermore, the junction chamfer setting of internal surface and surface, the border chamfer setting of osseointegration layer.

Use the technical scheme of the utility model acetabular cup, this acetabular cup has adopted the design of unbalanced thickness, in order to match the atress position of stress variation size respectively, it is concrete, the cup is the spherical body of lacking, an inside groove of processing on the plane of the spherical body of lacking, the inside groove is the spherical face of second, adopt the processing of rotary cutter to form, this spherical eccentric setting of second is on acetabular cup, it is thicker to make cup plane one side thickness thinner one side thickness like this, one side that thickness is thicker sets up in the top in order to bear great stress when using, one side that thickness is thinner sets up in the below in order to bear less stress relatively, the cup that sets up like this no matter is space or atress all more reasonable when the installation, the great one side of stress concentration fracture when having solved the unanimous cup of traditional thickness easily because of stress, cause the problem of cup damage.

Drawings

The accompanying drawings, which form a part of the present application, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention and not to limit the invention. In the drawings:

figure 1 shows a schematic structural view of an embodiment of an acetabular cup according to the invention; and

figure 2 shows a cross-sectional view of an embodiment of the acetabular cup of the invention.

Wherein the figures include the following reference numerals:

10. a cup body; 11. an outer surface; 12. an inner surface; 20. and (4) a osseointegration layer.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

Referring to fig. 1 and 2, the acetabular cup of this embodiment includes a cup body 10, the cup body 10 including an outer surface 11 and an inner surface 12, the outer surface 11 being a first spherical surface for engaging an acetabular socket, the inner surface 12 being a second spherical surface for engaging a femoral head; wherein, the center of the first spherical surface and the center of the second spherical surface have a distance therebetween, so that the thickness of the upper side of the cup body 10 of the outer surface 11 is greater than the thickness of the lower side of the cup body 10.

The utility model provides an acetabulum cup with stronger adaptability and longer service life, which adopts unbalanced thickness design to respectively match stress parts with different stress sizes, in particular, the cup body 10 is a spherical body, an inner groove is processed on the plane of the spherical body to form a second spherical surface, and the second spherical surface is processed by a rotary cutter, and is eccentrically arranged on the cup body 10 of the acetabulum cup, so that one side of the cup body 10 is thinner and the other side is thicker, the thicker side is arranged above to bear larger stress when in use, the thinner side is arranged below to bear relatively smaller stress, the cup body 10 which is arranged in the way is more reasonable in space and stress when in installation, the whole acetabulum cup is close to an equal stress state, stress concentration points and regions are eliminated or reduced, and the risk of ceramic prosthesis breakage is reduced, the problem of traditional cup 10 that thickness is unanimous is stressed when using the great easy fracture failure in one side, causes the cup 10 to damage is solved.

On the traditional metal material acetabular cup, the metal material has good ductility and toughness and good elasticity, so that the acetabular cup has high recovery capability after certain deformation, and the design of the acetabular cup with equal thickness is mostly adopted.

However, as the material science is improved, the ceramic material is more applied to the human joint replacement. While the ceramic material has good wear resistance and biocompatibility, the ceramic material has high brittleness and low deformation resistance, so that the ceramic material cannot be widely used on the prosthesis. Ceramic components have been used previously as lining components in conjunction with metallic acetabular cups, and metallic materials have been used on the outside of the ceramic components to reduce the risk of fracture failure due to brittle deformation.

The acetabular cup related in the embodiment is an isostress ceramic acetabular cup, and due to the variable thickness design, a thicker material structure is arranged in a region with larger stress of the acetabulum of a human body, so that the material deformation under high load can be resisted at the position, the stress of the whole acetabular cup is evenly distributed, and an isostress state is achieved.

As shown in FIG. 1, in the present embodiment, the distance between the first spherical surface and the second spherical surface is D, where 0 < D.ltoreq.2.5 mm. The acetabular cup of the embodiment can be designed according to the actual conditions of different patients during processing, so that the requirements of different patients or different body conditions can be met by different eccentric sizes during processing, and the overall structural strength of the acetabular cup can meet the use requirements.

Preferably, the center of the first spherical surface lies in the plane of the end surface of the cup 10. In this embodiment, the cup body 10 is preferably a semi-spherical structure, i.e. the first spherical surface is a half of a sphere, so that the acetabular cup can be conveniently installed and connected with the bone below the acetabular cup, and the acetabular cup is not easy to fall out.

Further, the center of the second spherical surface is located in the plane of the end surface of the cup body 10.

In this embodiment, the second spherical surface is also processed into a semi-spherical shape, wherein the spherical center of the second spherical surface and the spherical shape of the first spherical surface are both located on the end surface of the cup body 10 and are not overlapped, and the semi-spherical shape of the second spherical surface can effectively prevent the femoral head above the cup connected to the acetabulum cup from coming off the second spherical surface.

The thickness variation of the cup body 10 in this embodiment is obtained by vertically moving the center of the second spherical surface with respect to the center of the first spherical surface on the end surface, so that the model of the acetabular cup is represented by the diameters or radii of the first spherical surface and the second spherical surface, and the center deviation degree is increased, thereby obtaining richer acetabular cup performance, and making the mechanical performance of the entire acetabular cup closer to the biomechanical state of the human body.

The maximum thickness of the cup body 10 is d1, the minimum thickness of the cup body 10 is d2, wherein, 1.2 < d1/d2 < 1.5.

In this embodiment, the thickness design principle of the cup body 10 is that on the basis of being capable of bearing the movement pressure of a normal person, the thinner the cup body is, the better the occupied volume is, the installation is more convenient, in addition, in order to ensure the stress of the whole cup body 10 to be uniformly changed, the cup body 10 adopts a thickness gradual change mode, the smooth thinning from the upper end to the lower end of the cup body 10 does not generate a position where stress is concentrated, and the ratio of the thickness of the thickest position to the thickness of the thinnest position is 1.2 to 1.5.

The acetabular cup further includes an osseointegration layer 20 wrapped around the outer surface 11. The osseointegration layer 20 is less than the thickness of the cup 10.

The osseointegration layer 20 is uniformly applied to the outer surface 11 of the cup body 10 to form an osseointegration connection between the cup body 10 and the acetabular socket, and the osseointegration layer 20 may be provided on the inner surface 12 of the cup body 10 to facilitate connection of the cup body 10 to the upper femoral head.

The osseointegration layer 20 was formed using titanium and Hydroxyapatite (HA) spray. The cup body 10 is made of ceramic materials, and the cup body 10 is formed in a cutting mode.

In order to make acetabular femoral component life longer after installation in this embodiment, the result of use is better, and cup 10 adopts ceramic material to make, can effectively prevent rubbing, and does not have the corrosion problem that adopts metal material, and further, titanium and HA mixed spraying form osseointegration layer at cup 10's surface 11, make whole false body have good initial stability and osseointegration ability.

Further, the cup body 10 in the present embodiment is formed by cutting, so that the processing method of the acetabular cup is simplified, the existing combination of the acetabular cup and the lining is eliminated, the characteristics of high strength and high wear resistance of ceramic are effectively utilized, and the reconstruction of the acetabular structure and the good joint cross section can be obtained by using only one integrally formed acetabular cup.

In this embodiment, the junction of the outer surface 11 and the inner surface 12 is chamfered and the edge of the osseointegration layer 20 is chamfered, as shown in figure 2.

The design of edges and corners is avoided in each position of cup 10 in this embodiment, and stress concentration is reduced in the mode of circular arc transition, so the chamfer design is carried out at the edge of osseointegration layer 20 and the connection position of inner surface 12 and outer surface 11, and the force is effectively dispersed.

The iso-stressed acetabular cup in this embodiment, unlike the common concentric ball design, has different wall thicknesses at different locations. Typically, when implanting the acetabular cup, the surgeon directly implants the acetabular cup in the direction of the pelvic acetabular fossa. According to the physiological movement characteristics of human body, the stress of the acetabulum is mainly concentrated on one side part of the upper edge of the acetabulum, and the stress of other parts is smaller. For a typical acetabular cup, the stress distribution on the acetabular cup is highly non-uniform under such physiological conditions. Because the stress is different in magnitude and the acetabular cup has uniform wall thickness, the stress on the cross section is in a non-uniform state. Under such a stress environment, the acetabular cup may deform locally. For conventional metal cup-polyethylene lined prostheses, this local deformation can result in severe regional wear and ultimately failure of the prosthesis. This uneven deformation is more severe for ceramic materials, which in turn can lead to fracture of the ceramic material and greater patient injury.

The acetabular cup of this embodiment is shown in figures 1 and 2. The whole acetabulum cup is made of ceramic materials, and the ceramic materials have low hardness and are easy to machine before being sintered. Therefore, when the inner spherical joint surface is machined, the center of the machining tool is moved up and down, so that the thickness of the machined acetabular cup is changed on the whole.

Under the action of macroscopic external force, the inner spherical surface of the acetabular cup receives a force which is approximately gradually reduced from top to bottom. Due to the gradually changing thickness of the acetabular cup, the overall force applied to the acetabular cup will still tend to be uniform under such non-uniform forces. Without obvious stress concentration and local over-high stress, a relatively ideal stress state is achieved.

Although ceramics have high hardness and wear resistance, they still suffer from the disadvantages of brittle materials. The acetabular cup design form in the embodiment can effectively reduce acetabular cup breakage caused by overhigh local stress, and reduces the risk of prosthesis failure. Meanwhile, the outer surface of the acetabular cup in the embodiment is coated with titanium and HA to form an osseointegration layer. The whole prosthesis has good initial stability (thickness variation, no local stress concentration) and osseointegration capability (osseointegration layer).

The acetabular cup in the embodiment directly realizes two functions of acetabular position osseointegration and hip joint surface, and greatly reduces the complexity of prosthesis structure and surgical operation. Reducing the number of prosthesis components reduces the thickness of the prosthesis, substantially reducing the amount of bone removed, and the amount of bone remaining may provide a good basis for subsequent rehabilitation of the patient.

From the above description, it can be seen that the above-mentioned embodiments of the present invention achieve the following technical effects:

the utility model discloses well designed acetabular cup is the isostress structure, and the acetabular cup wholly adopts ceramic material. Before the ceramic material is sintered, the material has low hardness and is easier to machine. Therefore, when the inner spherical joint surface is machined, the center of the machining tool is translated left and right along the direction parallel to the plane of the cup body, so that the machined acetabular cup generates thickness change on the whole. Under the action of macroscopic external force, the inner spherical surface of the acetabular cup is subjected to a force which is approximately gradually reduced from top to bottom. Because the thickness of the acetabular cup changes gradually, the whole stress of the acetabular cup tends to be uniform under the action of the non-uniform force, and a relatively ideal stress state is achieved under the conditions of no obvious stress concentration and over-high local stress.

Although ceramics have high hardness and wear resistance, they still suffer from the disadvantages of brittle materials. The utility model provides an acetabular cup design form, the acetabular cup that can effectual reduction leads to because of local stress is too high is broken, has reduced the risk that the false body became invalid. Simultaneously, the utility model provides an acetabular cup is in the form of the outer surface applys titanium and HA spraying, forms osseointegration layer 20. The whole prosthesis has good initial stability and osseointegration capability. One prosthesis directly realizes two functions of acetabulum position osseointegration and hip joint surface, and greatly reduces the complexity of prosthesis structure and operation. Reducing the number of prosthesis components reduces the thickness of the prosthesis, substantially reducing the amount of bone removed, and the amount of bone remaining may provide a good basis for subsequent rehabilitation of the patient.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

Unless specifically stated otherwise, the relative arrangement of the components and steps, the numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present invention. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the orientation words such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" etc. are usually based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplification of description, and in the case of not making a contrary explanation, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore, should not be interpreted as limiting the scope of the present invention; the terms "inner and outer" refer to the inner and outer relative to the profile of the respective component itself.

Spatially relative terms, such as "above … …," "above … …," "above … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial relationship to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, devices described as "above" or "on" other devices or configurations would then be oriented "below" or "under" the other devices or configurations. Thus, the exemplary term "above … …" can include both an orientation of "above … …" and "below … …". The device may be otherwise variously oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

It should be noted that the terms "first", "second", and the like are used to define the components, and are only used for convenience of distinguishing the corresponding components, and if not stated otherwise, the terms have no special meaning, and therefore, the scope of the present invention should not be construed as being limited.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An acetabular cup, comprising:

a cup (10), said cup (10) including an outer surface (11) and an inner surface (12), said outer surface (11) being a first spherical surface for engaging with an acetabular socket and said inner surface (12) being a second spherical surface for engaging with a femoral head;

the distance is reserved between the spherical center of the first spherical surface and the spherical center of the second spherical surface, so that the thickness of the upper side of the cup body (10) is larger than that of the lower side of the cup body (10), the distance between the spherical center of the first spherical surface and the spherical center of the second spherical surface is D, and D is larger than 0 and smaller than or equal to 2.5 mm.

2. The acetabular cup of claim 1, wherein a center of the first spherical surface is in a plane of the end surface of the cup body.

3. The acetabular cup of claim 1, wherein a spherical center of the second spherical surface is located in a plane of the end surface of the cup body.

4. The acetabular cup of claim 1, wherein the maximum thickness of the cup body (10) is d1 and the minimum thickness of the cup body (10) is d2, wherein 1.2 < d1/d2 < 1.5.

5. The acetabular cup of claim 1, further comprising an osseointegration layer (20) wrapped around the outer surface.

6. The acetabular cup of claim 5, wherein the osseointegration layer (20) is less than the cup body (10) thickness.

7. The acetabular cup according to claim 5, wherein the osseointegration layer (20) is spray-formed using titanium and hydroxyapatite.

8. The acetabular cup of claim 1, wherein the cup body (10) is formed of a ceramic material and the cup body (10) is formed by cutting.

9. The acetabular cup according to claim 5, wherein the junction of the outer surface (11) and the inner surface (12) is chamfered, and the edge of the osseointegration layer (20) is chamfered.