Acetabular prosthesis and hip surface replacement system

Abstract

The present invention relates to an acetabular prosthesis and a hip joint surface replacement system. The acetabular prosthesis comprises a porous matrix and an ultra-high molecular weight polyethylene matrix connected to the porous matrix, wherein the porous matrix is ​​hemispherical; the ultra-high molecular weight polyethylene matrix is ​​fixed in a space surrounded by the porous matrix by die casting.

Description

Technical Field

[0001] The present invention relates to the technical field of artificial prostheses, in particular to an acetabular prosthesis and a hip joint surface replacement system. Background Art

[0002] Compared with total hip replacement, hip resurfacing can preserve more bone mass and better restore biomechanics in patients, and has better therapeutic effects on young patients with high activity demands.

[0003] Most of the existing hip joint surface replacement systems on the market are matched with each other's acetabular prosthesis and femoral prosthesis; the existing acetabular prosthesis is usually formed by combining two materials to meet the biological properties of the acetabular prosthesis. However, the degree of integration between the two materials of the existing acetabular prosthesis is poor and cannot meet the strength requirements of normal hip movement of the human body. Summary of the invention

[0004] Based on this, it is necessary to provide an improved acetabular prosthesis and hip joint surface replacement system to address the above-mentioned problems.

[0005] An acetabular prosthesis comprises a porous matrix and an ultra-high molecular weight polyethylene matrix connected to the porous matrix; the ultra-high molecular weight polyethylene matrix is ​​fixed in a space surrounded by the porous matrix by die-casting.

[0006] Furthermore, the porous matrix includes a porous outer layer and a porous inner lining layer fixed to each other, and the porous outer layer is located on the outside of the porous matrix, the porous inner lining layer is located between the porous outer layer and the ultra-high molecular weight polyethylene matrix, and the ultra-high molecular weight polyethylene matrix penetrates into and is fixed to the porous inner lining layer.

[0007] Furthermore, the porosity of the porous outer layer is above 50%; and / or,

[0008] The porosity of the porous lining layer is above 20%.

[0009] Furthermore, the porous matrix further includes a dense layer, and the dense layer is formed between the porous outer layer and the porous inner lining layer.

[0010] Furthermore, the thickness t1 of the porous outer layer satisfies the following relationship: 0.5 mm ≤ t1 ≤ 2 mm; and / or,

[0011] The thickness t2 of the dense layer satisfies the following relationship: 0.1 mm ≤ t2 ≤ 2 mm; and / or,

[0012] The thickness t3 of the porous lining layer satisfies the following relationship: 0.2 mm ≤ t2 ≤ 3 mm.

[0013] Furthermore, the porous matrix is ​​a titanium alloy matrix.

[0014] Furthermore, the porous matrix is ​​integrally formed by 3D printing.

[0015] An embodiment of the present invention further provides a hip joint surface replacement system, comprising an acetabular prosthesis and a femoral prosthesis that cooperate with each other; the acetabular prosthesis is the acetabular prosthesis as described in any one of the above items.

[0016] Furthermore, the femoral prosthesis comprises a spherical joint portion and a connecting portion fixed to each other, the spherical joint portion is used to cooperate with the ultra-high molecular weight polyethylene matrix, and the connecting portion is used to be implanted in the femur corresponding to the acetabular prosthesis;

[0017] Furthermore, the femoral prosthesis further comprises a wear-resistant layer on the outer side of the spherical joint portion.

[0018] Furthermore, the wear-resistant layer includes at least one of TiN, TiNbN and DLC film.

[0019] An acetabular prosthesis is provided in one embodiment of the present invention. By directly die-casting an ultra-high molecular weight polyethylene matrix into a porous matrix, the connection strength between the ultra-high molecular weight polyethylene matrix and the porous matrix is ​​correspondingly improved, so that the acetabular prosthesis can meet the strength requirements of normal hip movement in the human body. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic structural diagram of a hip joint surface replacement system in one embodiment of the present invention;

[0021] Figure 2 for Figure 1 A schematic diagram of the structure of the acetabular prosthesis in the hip surface replacement system shown;

[0022] Figure 3 for Figure 2 The schematic diagram of the structure of the acetabular prosthesis at A is shown;

[0023] Figure 4 A schematic diagram of the partial structure of an acetabular prosthesis in a hip joint surface replacement system according to another embodiment of the present invention;

[0024] Figure 5 for Figure 1 Schematic diagram of the structure of the femoral prosthesis in the hip surface replacement system.

[0025] Component number description

[0026] 100. Hip joint surface replacement system; 10. Acetabular prosthesis; 11. Porous matrix; 111. Porous outer layer; 112. Porous lining layer; 113. Dense layer; 12. Ultra-high molecular weight polyethylene matrix; 20. Femoral prosthesis; 21. Spherical joint part; 22. Connecting part; 23. Wear-resistant layer.

[0027] The above description of the main component symbols is combined with the accompanying drawings and specific implementation methods to further illustrate the present invention in detail. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be understood that the specific implementation methods described herein are only used to explain the present invention and do not limit the scope of protection of the present invention.

[0029] It should be noted that when a component is referred to as being "mounted on" another component, it may be directly on the other component or there may also be a centered component. When a component is considered to be "set on" another component, it may be directly set on the other component or there may also be a centered component. When a component is considered to be "fixed to" another component, it may be directly fixed on the other component or there may also be a centered component. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "or / and" used herein includes any and all combinations of one or more related listed items.

[0031] One embodiment of the present invention provides a hip joint surface replacement system. The hip joint surface replacement system is used to replace the original damaged acetabulum joint and the corresponding femoral part in hip joint replacement surgery to maintain normal human activity requirements.

[0032] See also Figure 1 , Figure 1 FIG. 1 is a schematic structural diagram of a hip joint surface replacement system 100 according to an embodiment of the present invention.

[0033] The hip joint surface replacement system 100 includes an acetabular prosthesis 10 and a femoral prosthesis 20. The acetabular prosthesis 10 and the femoral prosthesis 20 are installed in the human body and cooperate with each other to replace the damaged part of the human hip joint to maintain the normal physiological function of the human acetabular joint. The acetabular prosthesis 10 is used to replace the damaged part of the hip bone in the human body and is fixed to the normal hip bone part by fasteners made of special materials; the femoral prosthesis 20 is fixed in the femur by fasteners and is aligned with the acetabular prosthesis 10.

[0034] See also Figure 2 , Figure 2 for Figure 1 The structure of the acetabular prosthesis 10 in the hip joint surface replacement system 100 is shown.

[0035] The acetabular prosthesis 10 includes a porous matrix 11 and an ultra-high molecular weight polyethylene matrix 12 connected to the porous matrix 11. The porous matrix 11 is used to face and be connected to the normal side of the human hip bone. The ultra-high molecular weight polyethylene matrix 12 is fixed to the porous matrix 11, and the ultra-high molecular weight polyethylene matrix 12 is used to face the femoral prosthesis 20 in the hip joint surface replacement system 100 and cooperate with the femoral prosthesis 20 to replace the original joint movement between the hip bone and the femur in the human body.

[0036] The porous matrix 11 is roughly hemispherical. The outer side of the porous matrix 11 can be connected to the normal side of the hip bone; the inner wall of the space formed by the porous matrix 11 can be fixed to the ultra-high molecular weight polyethylene matrix 12. The shape of the ultra-high molecular weight polyethylene matrix 12 is roughly the same as the inner wall shape of the porous matrix 11, and the space formed by the enclosed space can be used to wrap the femoral prosthesis 20, so that a normal joint connection is formed between the femoral prosthesis 20 and the ultra-high molecular weight polyethylene matrix 12.

[0037] It is understandable that in other embodiments, the outer contour of the acetabular prosthesis 10 may also be configured to be other structural shapes that match the normal side of the hip bone, as long as a fixed connection with the normal side of the hip bone can be achieved.

[0038] The hip bone and the femur have a large range of joint motion and are one of the joints in the human body that bear the greatest force. Therefore, the acetabular prosthesis 10 or the femoral prosthesis 20 in the hip joint surface replacement system 100 of the present application has high requirements for the strength of the force, and also needs to have certain biocompatibility and good wear resistance.

[0039] In the present application, the acetabular prosthesis 10 is fixed by the porous matrix 11 and the ultra-high molecular weight polyethylene matrix 12 so that the acetabular prosthesis 10 meets the above requirements. Due to the presence of pores in the porous matrix 11, the porous matrix 11 and the normal side of the hip bone can fuse with each other after hip replacement surgery and grow stably to ensure the bone growth of the acetabular prosthesis 10. Due to the inherent properties of the ultra-high molecular weight polyethylene material, the ultra-high molecular weight polyethylene matrix 12 makes the acetabular prosthesis 10 facing the femoral prosthesis 20 have super wear resistance and self-lubrication, while also having high strength, stable chemical properties and extremely strong anti-aging properties. All of the above characteristics show the unique performance advantages of the ultra-high molecular weight polyethylene matrix 12.

[0040] It should be explained that the ultra-high molecular weight polyethylene matrix 12 is made of ultra-high molecular weight polyethylene material. The ultra-high molecular weight polyethylene material is a polyethylene material with a molecular weight of more than 1.5 million and a high degree of cross-linking. Since ultra-high molecular weight polyethylene (UHMW-PE) has extremely poor fluidity in a molten state and its melt index is almost zero, it is difficult to process it using general mechanical processing methods.

[0041] Due to the material properties of the ultra-high molecular weight polyethylene, such as high surface finish, the bonding between the ultra-high molecular weight polyethylene matrix 12 and the porous matrix 11 is not high, and the interface between the two is relatively obvious. Even by spraying, it is difficult to make the ultra-high molecular weight polyethylene matrix and the porous matrix fuse well. If the bonding between the two is not high, the dorsal side of the acetabular prosthesis will be worn out after long-term use, which will seriously affect the movement of the patient's joint; if the dorsal side of the acetabular prosthesis is severely worn, the acetabular prosthesis needs to be re-repaired, which will cause the patient to undergo a second surgery.

[0042] Please also read Figure 3 and Figure 4 , Figure 3 for Figure 2 The schematic diagram of the structure of the acetabular prosthesis 10 shown is at A;

[0043] Figure 4 It is a schematic diagram of the partial structure of the acetabular prosthesis 10 in the hip joint surface replacement system 100 according to another embodiment of the present invention.

[0044] Based on the above problems, the porous matrix 11 and the ultra-high molecular weight polyethylene matrix 12 in the present application are fixed by die-casting, so that the ultra-high molecular weight polyethylene matrix 12 can be better combined with the porous matrix 11. Die-casting is to quickly form the ultra-high molecular weight polyethylene matrix 12 in the space enclosed by the porous matrix 11 under a certain high pressure and hot melting, and form a good connection force with the porous matrix 11. The ultra-high molecular weight polyethylene quickly extends into the porous matrix 11. The porous matrix 11 and the ultra-high molecular weight polyethylene matrix 12 are combined into an integrated structure by die-casting, and there is no dorsal wear problem of conventional modular prostheses, which can correspondingly increase the service life of the acetabular prosthesis.

[0045] In the above-mentioned die-casting process, by controlling the pressure and speed of the die-casting tool during die-casting, the porous matrix 11 can form a porous outer layer 111 and a porous inner lining layer 112 correspondingly during the die-casting process. The porous outer layer 111 is located on the outside of the porous matrix 11 and is used to be fixed to the normal side of the hip bone so that the two can be fused with each other; the pores on the porous outer side can serve as a growth matrix for bone cells on the normal side of the hip bone. The porous inner lining layer 112 is located between the porous outer layer 111 and the ultra-high molecular weight polyethylene matrix 12; the porous inner lining layer 112 is used for the ultra-high molecular weight polyethylene matrix 12 to penetrate and fix. The ultra-high molecular weight polyethylene is die-casted and combined with the porous layer in a molten state. When the ultra-high molecular weight polyethylene matrix 12 penetrates into the porous inner lining layer 112, the material of the ultra-high molecular weight polyethylene matrix 12 penetrates into the pores of the porous inner lining layer 112, so that the bonding strength between the two is increased.

[0046] The mechanical properties of the acetabular prosthesis 10 formed by die casting are greatly improved. Compared with the conventional polyethylene surface coating, the mechanical properties of the acetabular prosthesis 10 are improved in that the bonding strength between the porous liner layer 112 and the ultra-high molecular weight polyethylene matrix 12 is better; and after bonding, there is no micro-motion wear between the polyethylene and the porous matrix 11 that exists in the conventional assembly type.

[0047] Those skilled in the art often combine the porous matrix 11 and the ultra-high molecular weight polyethylene matrix 12 by spraying or the like, and since the thickness of the sprayed ultra-high molecular weight polyethylene is relatively small, those skilled in the art usually do not think of combining the two by die-casting.

[0048] In this embodiment, the porous matrix 11 is a titanium alloy matrix. Titanium alloy has high mechanical strength and metal memory characteristics, so that titanium alloy can act as a good matrix in the prosthesis and the acetabular prosthesis 10 formed by it can better adapt to human bones.

[0049] In one embodiment, the porous matrix 11 is integrally formed by 3D printing. The porous matrix 11 formed by 3D printing not only ensures the connection strength between the porous outer side and the porous inner lining layer 112, but also can independently control the porosity of the porous outer side and the porous inner lining layer 112 through the parameter setting of 3D printing. Such a setting makes the porous matrix 11 easy to produce and form, and the corresponding porosity can be independently set to a more ideal porosity, so that the ultra-high molecular weight polyethylene matrix 12 can be better integrated into the porous matrix 11 through die casting.

[0050] In one embodiment, the porosity of the porous outer layer 111 is above 50%; and / or the porosity of the porous lining layer 112 is above 20%. The porosity of the porous outer layer 111 is set to be above 50% to provide a better growth space for the normal side of the hip bone; the porosity of the porous lining layer 112 is above 20% to ensure that the porous lining layer 112 has sufficient pores for the ultra-high molecular weight polyethylene matrix 12 to penetrate, so as to ensure the bonding strength between the ultra-high molecular weight polyethylene matrix 12 and the porous matrix 11.

[0051] In one embodiment, the porous matrix 11 further includes a dense layer 113. The dense layer 113 is formed between the porous outer layer 111 and the porous inner lining layer 112; and the dense layer 113 is used to prevent the ultra-high molecular weight polyethylene matrix 12 from penetrating into the porous outer layer 111, so as to ensure the porosity of the porous outer layer 111, and enable the pores of the porous inner lining layer 112 to be better filled with the ultra-high molecular weight polyethylene matrix 12. Due to the presence of the porous outer layer 111 and the porous inner lining layer 112, the ultra-high molecular weight polyethylene matrix 12 is easy to penetrate the porous matrix 11 when being pressed against the porous matrix 11, so that the pores of the porous outer layer 111 are also filled with the ultra-high molecular weight polyethylene material, which affects the connection performance of the acetabular prosthesis 10 with the normal side of the hip bone. In order to avoid the above problems, a dense layer 113 is provided between the porous outer layer 111 and the porous inner lining layer 112. In this way, the porous matrix 11 and the ultra-high molecular weight polyethylene matrix 12 can be better combined. The acetabular prosthesis 10 formed by the combination of the two has greatly improved overall mechanical properties and bone compatibility with the human body, and can better adapt to the human body.

[0052] The dense layer 113 is provided to prevent the ultra-high molecular weight polyethylene matrix 12 from penetrating into the porous outer layer 111 during die casting, and at the same time, the rigidity of the overall porous matrix 11 can be improved. Due to the presence of the dense layer 113, the overall hardness of the porous matrix 11 is greatly improved, so that the overall rigidity of the porous matrix 11 is increased, and the corresponding overall thickness of the porous matrix 11 can be correspondingly thinned. In the present application, the connection strength between the ultra-high molecular weight polyethylene matrix 12 and the porous matrix 11 is greatly improved by the provision of the dense layer 113; therefore, the overall thickness of the porous matrix 11 can be reduced accordingly, and the overall rigidity of the porous matrix 11 is significantly improved. In the field of prostheses, thinning the overall thickness of the prosthesis requires consideration of various factors, such as whether it can have sufficient bonding strength with the normal side of the human bone or whether the strength of the prosthetic joint itself is sufficient, so it is not a problem that can be solved by only thinning the thickness of the prosthesis by those skilled in the art.

[0053] The porous outer layer 111, the dense layer 113 and the porous lining layer 112 of the porous substrate 11 are integrally formed by 3D printing, so that the connection strength between the layers of the porous substrate 11 can be ensured.

[0054] It is understood that in other embodiments, if the penetration of the ultra-high molecular weight polyethylene matrix 12 is not considered, the corresponding dense layer 113 can be omitted accordingly. Figure 4 As shown, the porous matrix is ​​a porous structure as a whole, with a thickness between 1.2 mm and 5 mm and a porosity between 20% and 90%. The ultra-high molecular weight polyethylene matrix 12 penetrates into the porous lining layer 112 area to achieve complete locking and fixation between the two components, and the porous outer layer 111 area still has enough thickness for bone growth.

[0055] Further, the thickness t1 of the porous outer layer 111 satisfies the following relationship: 0.5 mm ≤ t1 ≤ 2 mm; and / or, the thickness t2 of the dense layer 113 satisfies the following relationship: 0.1 mm ≤ t2 ≤ 2 mm; and / or, the thickness t3 of the porous lining layer 112 satisfies the following relationship: 0.2 mm ≤ t3 ≤ 1.5 mm. In this way, the thickness of the porous outer layer 111 is set so that the normal side of the hip bone can have enough growth space, so that the normal side of the hip bone and the acetabular prosthesis have sufficient connection strength. The thickness of the porous lining layer 112 is set to have sufficient bonding strength with the ultra-high molecular weight polyethylene matrix 12 after die-casting, and the thickness will not increase the burden on the patient; in addition, under the premise that the total thickness of the porous lining layer 112 and the ultra-high molecular weight polyethylene matrix 12 remains unchanged, and under the condition of ensuring the bonding strength between the porous lining layer 112 and the ultra-high molecular weight polyethylene matrix 12, the thickness of the ultra-high molecular weight polyethylene matrix 12 can be as thick as possible to increase the wear resistance of the acetabular prosthesis 10 during operation. Due to the limitation of the process, the thickness of the dense layer 113 is controlled to be 0.1mm≤t2≤2mm. Too thick will increase the overall thickness of the acetabular prosthesis 10 and increase the burden on the patient.

[0056] See also Figure 5 , Figure 5 for Figure 1 FIG. 1 is a schematic structural diagram of a femoral prosthesis 20 in a hip joint surface replacement system 100 .

[0057] The femoral prosthesis 20 includes a spherical joint portion 21 and a connecting portion 22 fixed to each other. The spherical joint portion 21 is used to cooperate with the ultra-high molecular weight polyethylene matrix 12; the connecting portion 22 is used to be implanted in the femur corresponding to the acetabular prosthesis 10. The surface of the spherical joint portion 21 facing the normal side of the femur is provided with a 3D printed porous structure (unnumbered). The thickness of the porous structure is between 0.5 mm and 2 mm, and the average porosity is above 50%. The porous structure can achieve biological fixation through its good bone ingrowth. Compared with traditional bone cement, the femoral prosthesis 20 has better long-term stability.

[0058] It should be explained that the femur corresponding to the hip osteotomy site also needs to be replaced with a femoral prosthesis 20 that matches the acetabulum prosthesis 10; the normal side of the femur refers to the position used to install the femoral prosthesis 20 and in contact with the femoral prosthesis 20 after the femoral osteotomy.

[0059] In one embodiment, in order to increase the wear resistance of the spherical joint portion 21 of the femoral prosthesis 20 and the ultra-high molecular weight polyethylene matrix 12, the femoral prosthesis 20 further includes a wear-resistant layer 23. The wear-resistant layer 23 is disposed at a position of the spherical joint portion 21 away from the normal side of the femur. The wear-resistant layer 23 is used to increase the wear resistance between the spherical joint portion 21 and the ultra-high molecular weight polyethylene matrix 12, so as to extend the service life of the femoral prosthesis 20.

[0060] In one embodiment, the wear-resistant layer 23 includes at least one of TiN, TiNbN and DLC (Diamond Like Carbon) films. TiN, TiNbN and DLC film materials can effectively increase the wear resistance of the spherical joint part 21, thereby extending the service life of the hip joint surface replacement system 100.

[0061] It can be understood that in other embodiments, the wear-resistant layer 23 can also be made of other materials with good wear resistance.

[0062] An embodiment of the present invention provides an acetabular prosthesis, which combines a porous matrix with an ultra-high molecular weight polyethylene matrix by die-casting, thereby avoiding the back wear problem of the conventional modular prosthesis and improving the life of the prosthesis.

[0063] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0064] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An acetabular prosthesis, characterized in that: The acetabular prosthesis includes a porous matrix and an ultra-high molecular weight polyethylene matrix connected to the porous matrix; the ultra-high molecular weight polyethylene matrix is ​​fixed in the space formed by the porous matrix by die-casting, and the porous matrix and the ultra-high molecular weight polyethylene matrix are combined into an integrated structure; the porous matrix includes a porous outer layer and a porous lining layer fixed to each other, and the porous outer layer is located on the outside of the porous matrix, the porous lining layer is located between the porous outer layer and the ultra-high molecular weight polyethylene matrix, and the ultra-high molecular weight polyethylene matrix penetrates into and is fixed to the porous lining layer; the porous matrix also includes a dense layer, and the dense layer is formed between the porous outer layer and the porous lining layer; The porosity of the porous outer layer is above 50%; and / or the porosity of the porous inner lining layer is above 20%.

2. The acetabular prosthesis according to claim 1, characterized in that: The thickness t1 of the porous outer layer satisfies the following relationship: 0.5 mm ≤ t1 ≤ 2 mm; and / or, The thickness t2 of the dense layer satisfies the following relationship: 0.1 mm ≤ t2 ≤ 2 mm; and / or, The thickness t3 of the porous lining layer satisfies the following relationship: 0.2 mm ≤ t2 ≤ 3 mm.

3. The acetabular prosthesis according to claim 1, characterized in that: The porous matrix is ​​a titanium alloy matrix.

4. The acetabular prosthesis according to claim 1, characterized in that: The porous matrix is ​​integrally formed by 3D printing.

5. A hip joint surface replacement system, comprising an acetabular prosthesis and a femoral prosthesis that cooperate with each other; characterized in that: The acetabular prosthesis is the acetabular prosthesis according to any one of claims 1 to 4.

6. The hip joint surface replacement system according to claim 5, characterized in that: The femoral prosthesis comprises a spherical joint portion and a connecting portion fixed to each other, the spherical joint portion is used to cooperate with the ultra-high molecular weight polyethylene matrix, and the connecting portion is used to be implanted in the femur corresponding to the acetabular prosthesis; Furthermore, the femoral prosthesis further comprises a wear-resistant layer on the outer side of the spherical joint portion.

7. The hip joint surface replacement system according to claim 6, characterized in that: The wear-resistant layer includes at least one of TiN, TiNbN and DLC film.

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