Hip joint femoral prosthesis

Abstract

The invention provides a hip joint thighbone prosthesis, and relates to the technical field of artificial joint prostheses, the hip joint thighbone prosthesis comprises a thighbone prosthesis main body, a plurality of anti-rotation keels are arranged on the inner surface of a spherical joint part, the plurality of anti-rotation keels are arranged along the circumferential direction of a connecting part, and the spherical joint part is connected with the thighbone prosthesis main body. The multiple anti-rotation keels divide the inner surface of the spherical joint part into multiple outer areas, and the pore diameters of the porous structures of the adjacent outer areas are different. According to the hip joint femoral prosthesis provided by the invention, the plurality of anti-rotation keels are arranged on the inner surface of the spherical joint part of the femoral prosthesis main body, and the anti-rotation keels can effectively improve the anti-rotation effect of the hip joint femoral prosthesis; the anti-rotation keel enables the inner surface to form a plurality of outer areas, and the pore diameters of the porous structures of the adjacent outer areas are different, that is, each outer area corresponds to different bone density areas of the femoral head, so that the problem of prosthesis looseness caused by biomechanical mismatching of the prosthesis and the host bone is solved.

Description

Technical Field

[0001] This invention relates to the technical field of artificial joint prostheses, and in particular to a hip joint femoral prosthesis. Background Technology

[0002] Hip resurfacing arthroplasty (HRA) is an effective surgical procedure for treating end-stage hip osteoarthritis, femoral head necrosis, and developmental dysplasia of the hip. Compared to total hip arthroplasty (THA), this procedure preserves the femoral head and neck, replacing only the damaged or diseased joint surface with a metal cup-shaped prosthesis, thereby achieving pain relief and restoration of hip function. Because HRA preserves bone mass to the maximum extent, it is particularly suitable for young, highly active patients.

[0003] Currently, most resurfacing hip replacement femoral components in clinical practice use bone cement for fixation. While bone cement provides good immediate stability post-surgery, it carries the risk of aging and fracture, potentially leading to prosthesis loosening and failure. Furthermore, bone cement releases a significant amount of heat during curing, easily causing thermal damage to local bone tissue. To overcome these limitations, bio-based resurfacing hip replacement femoral components that do not require bone cement fixation have emerged in recent years. These prostheses rely on bone tissue ingrowth into or onto a porous coating on their surface to achieve cross-locking fixation at the interface, theoretically offering a longer lifespan.

[0004] Existing biocompatible surface-mount hip arthroplasty (HRA) techniques often employ porous coatings, such as plasma-sprayed titanium coatings or hydroxyapatite coatings. However, these coatings still have several shortcomings. On the one hand, insufficient surface roughness of the coating reduces the initial stability of the prosthesis, thus affecting bone ingrowth. On the other hand, low porosity of the coating restricts bone tissue attachment and nutrient transport, hindering osseointegration. Furthermore, insufficient bonding between the coating and the metal substrate poses a risk of coating detachment. In addition to coating issues, stress shielding-induced bone resorption is also a significant cause of HRA failure, clinically manifesting as femoral head collapse and prosthesis loosening due to bone cavity formation. Traditional porous coatings are typically homogeneous, but studies have found that the trabeculae within the femoral head exhibit regional heterogeneous distribution: when the femoral head is divided into three equal layers (upper, middle, and lower) in cross-section, the bone density is higher in the central region of the upper layer, lower in the medial regions of the middle and lower layers, and intermediate in the anterior and posterior regions of the top and middle layers, exhibiting significant regional structural differences. The current uniform porous coatings are insufficient to meet the biomechanical requirements of different areas of bone tissue, that is, different areas require different levels of mechanical stimulation, which affects the long-term stability of the prosthesis.

[0005] Regarding prosthetic materials, the vast majority of femoral components for resurfacing hip joint replacements are still made of metal, commonly including cobalt-chromium-molybdenum alloys and titanium alloys, with ceramic materials used in a few cases. While cobalt-chromium-molybdenum alloys possess excellent mechanical properties, their wear resistance and biocompatibility are insufficient, posing risks such as aseptic loosening induced by wear particles, metal ion release, and related allergic reactions. On the other hand, while ceramic materials have good wear resistance and biocompatibility, they carry a risk of fracture, limiting their clinical application. Summary of the Invention

[0006] The purpose of this invention is to provide a femoral prosthesis for the hip joint to alleviate the technical problem that the trabeculae inside the femoral head are unevenly distributed in different regions, but the uniform porous coating on the surface of the hip joint is difficult to meet the biomechanical requirements of bone tissue in different regions, thus affecting the long-term stability of the prosthesis.

[0007] The present invention provides a femoral prosthesis for a hip joint, comprising a femoral prosthesis body, the femoral prosthesis body including a ball joint portion and a connecting portion, the ball joint portion having an opening, and the connecting portion being inserted through the opening and connected to the interior of the ball joint portion; The inner surface of the spherical joint is provided with a porous structure layer, and multiple anti-rotation keels are provided on the inner surface of the spherical joint. The multiple anti-rotation keels are arranged circumferentially along the connecting part, and the multiple anti-rotation keels divide the inner surface of the spherical joint into multiple outer regions. The pore size of the porous structure of adjacent outer regions is different.

[0008] In an optional embodiment, an inner region is formed around the connecting portion on the inner surface of the ball joint, and a plurality of outer regions are distributed around the inner region. In an optional embodiment, four anti-rotation keels are provided on the inner surface of the ball joint portion, and the anti-rotation keels are connected to the ball joint portion through the porous structure layer. The anti-rotation keel divides the inner surface of the ball joint into four outer regions, namely the first outer region, the second outer region, the third outer region, and the fourth outer region; The first outer region and the fourth outer region are disposed on both sides of the connecting part, and the second outer region and the third outer region are disposed on both sides of the connecting part.

[0009] In an optional embodiment, the pore size of the first outer region is between 0.18 mm and 0.28 mm, and the porosity is between 55% and 65%.

[0010] In an optional embodiment, the pore size of the second outer region and the third outer region is between 0.28 mm and 0.38 mm, and the porosity is between 66% and 75%. In an optional embodiment, the pore size of the fourth outer region and the inner region is between 0.36 mm and 0.65 mm, and the porosity is between 76% and 85%.

[0011] In an optional embodiment, the anti-spin keel protrudes 1mm-3mm from the surface of the porous structure layer 200; and the width of the anti-spin keel is between 1mm-4mm. In an optional implementation, the outer diameter of the inner region is between 12mm and 24mm. In an optional implementation, the outer region is fan-shaped, and the central angle of the outer region is between 80° and 110°.

[0012] In an optional embodiment, the porous structure can be one of the following cell structures: octahedron, body-centered cubic, rhombic dodecahedron, or three-period minimal surface.

[0013] The femoral prosthesis of the hip joint provided by the present invention has multiple anti-rotation keels on the inner surface of the ball joint portion of the femoral prosthesis body. The anti-rotation keels can effectively improve the anti-rotation effect of the femoral prosthesis of the hip joint. Moreover, the anti-rotation keels make the multiple outer regions formed on the inner surface have different pore sizes in the porous structure of adjacent outer regions. That is, each outer region corresponds to a different bone density region of the femoral head, which solves the problem of prosthesis loosening caused by biomechanical mismatch between the prosthesis and the host bone. Attached Figure Description

[0014] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the structure of the hip joint femoral prosthesis provided in an embodiment of the present invention; Figure 2 for Figure 1 A schematic diagram of the hip joint femoral prosthesis from another angle; Figure 3 for Figure 1 The diagram shows a cross-sectional view of the femoral prosthesis for the hip joint.

[0016] Icons: 100 - Ball joint; 200 - Porous structure layer; 300 - Connector; 400 - Anti-rotation keel; 500 - First outer zone; 600 - Second outer zone; 700 - Third outer zone; 800 - Fourth outer zone; 900 - Inner zone. Detailed Implementation

[0017] The terms “first,” “second,” “third,” etc., are used only for distinguishing descriptions and do not indicate a sequence number, nor should they be interpreted as indicating or implying relative importance.

[0018] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0019] In the description of this application, it should be noted that the terms "inner", "outer", "left", "right", "upper", "lower", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this application is in use. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0020] In the description of this application, unless otherwise expressly specified and limited, the terms “set up,” “install,” “connect,” and “link” shall be interpreted broadly, for example, as a fixed connection, a detachable connection, or an integral connection; as a mechanical connection or an electrical connection; as a direct connection or an indirect connection through an intermediate medium; or as a connection within two components.

[0021] The technical solution of this application will now be clearly and completely described with reference to the accompanying drawings.

[0022] Example Reference Figures 1-3 The present invention provides a hip joint femoral prosthesis, including a femoral prosthesis body, the femoral prosthesis body including a ball joint portion 100 and a connecting portion 300, the ball joint portion 100 having an opening, and the connecting portion 300 being inserted through the opening and connected to the interior of the ball joint portion 100. The inner surface of the spherical joint portion 100 is provided with a porous structure layer 200, and a plurality of anti-spin keels 400 are provided on the inner surface of the spherical joint portion 100. The plurality of anti-spin keels 400 are arranged along the circumference of the connecting portion 300, and the plurality of anti-spin keels 400 divide the inner surface of the spherical joint portion 100 into a plurality of outer regions, and the pore size of the porous structure of adjacent outer regions is different.

[0023] In some embodiments, the femoral prosthesis body of the hip joint femoral prosthesis includes a ball joint portion 100 and a connecting portion 300, one end of which is connected to the interior of the ball joint portion 100; a porous structure layer 200 is provided on the inner surface of the ball joint portion 100, and an anti-rotation keel 400 divides the inner surface of the ball joint portion 100 into multiple outer regions, the pore sizes of the porous structures in adjacent outer regions are different, that is, the pore sizes of non-adjacent outer regions may be the same.

[0024] The ball joint portion 100 is used to connect with the femur. Each outer region of the ball joint portion 100 corresponds to a different bone density region of the femoral head section. The pore size of the porous structure of each outer region corresponds to the bone density of the corresponding region of the femoral head section. This can meet the biomechanical needs of bone tissue in different regions and effectively reduce the risk of prosthesis loosening caused by postoperative stress shielding.

[0025] Hip joint femoral prostheses improve long-term survival and solve the problems of insufficient bone ingrowth and prosthesis loosening caused by biomechanical mismatch with the host bone in existing biological prostheses.

[0026] In an optional embodiment, an inner region 900 is formed around the connecting portion 300 on the inner surface of the ball joint portion 100, and a plurality of outer regions are distributed around the inner region 900. In an optional embodiment, four anti-rotation keels 400 are provided on the inner surface of the ball joint portion 100, and the anti-rotation keels 400 are connected to the ball joint portion 100 through the porous structure layer 200. The anti-rotation keel 400 divides the inner surface of the ball joint portion 100 into four outer regions, namely the first outer region 500, the second outer region 600, the third outer region 700 and the fourth outer region 800. The first outer region 500 and the fourth outer region 800 are disposed on both sides of the connecting portion 300, and the second outer region 600 and the third outer region 700 are disposed on both sides of the connecting portion 300.

[0027] In some embodiments, the inner surface of the ball joint portion 100 is divided into a first outer region 500, a second outer region 600, a third outer region 700, a fourth outer region 800, and an inner region 900; while the femoral head is divided into three equal layers: upper, middle, and lower. The bone density of the upper central region is higher, while the bone density of the medial region of the middle layer and the lower medial region is lower. The bone density of the anterior and posterior regions of the top and middle layers is between the two, showing obvious regional structural differences. The first outer region 500 corresponds to the upper central region of the femur, the second outer region 600 and the third outer region 700 correspond to the anterior and posterior regions of the middle layer of the femur, and the fourth region and the inner region 900 correspond to the medial region of the middle layer and the lower medial region of the femur.

[0028] The osseointegration interface is designed according to the distribution pattern of trabecular bone in the human femoral head, enabling targeted matching of the mechanical adaptation needs of bone tissue in different areas. Based on the position of the prosthesis after implantation, and viewed from a perspective perpendicular to the prosthesis's equatorial plane, the osseointegration interface is divided into five regions. The first outer region (500), second outer region (600), third outer region (700), and fourth outer region (800) are fan-shaped, with angular curvatures between 80° and 110°. The inner region (900) is annular, with its center point and the prosthesis surface apex traversed by the axis of the solid connecting portion (300).

[0029] In an optional embodiment, the pore size of the first outer region 500 is between 0.18 mm and 0.28 mm, and the porosity is between 55% and 65%.

[0030] In an optional embodiment, the pore size of the second outer region 600 and the third outer region 700 is between 0.28 mm and 0.38 mm, and the porosity is between 66% and 75%. In an optional embodiment, the pore size of the fourth outer region 800 and the inner region 900 is between 0.36 mm and 0.65 mm, and the porosity is between 76% and 85%.

[0031] In some embodiments, the pore size of the porous structure in the first outer region 500 is smaller than that in the second outer region 600 and the third outer region 700, and the pore size of the porous structure in the second outer region 600 and the third outer region 700 is smaller than that in the fourth outer region 800 and the inner region 900; and the porosity of the porous structure is 100%.

[0032] Reference Figure 1 In an optional embodiment, the anti-spin keel 400 protrudes 1mm-3mm from the surface of the porous structure layer 200; and the width of the anti-spin keel 400 is between 1mm-4mm. In some embodiments, the anti-spin keel 400 is directly connected to the inner surface of the ball joint portion 100, that is, the anti-spin keel 400 is not disposed on the porous structure layer 200; the edge of the porous structure layer 200 is connected to the side of the anti-spin keel 400.

[0033] The anti-rotation keel 400 protrudes 1mm-3mm from the surface of the porous structure layer 200, with a width of 1mm-4mm, and typically has a rectangular cross-section. By incorporating the anti-rotation keel 400, the initial stability of the hip joint femoral prosthesis after implantation can be significantly improved, avoiding bone ingrowth failure caused by excessive micromovement at the bone-prosthesis interface. Simultaneously, the anti-rotation keel 400 also enhances the bonding strength between the porous structure and the matrix, significantly reducing the risk of porous structure detachment.

[0034] In an optional embodiment, the outer diameter of the inner region 900 is between 12 mm and 24 mm. In an optional implementation, the outer region is fan-shaped, and the central angle of the outer region is between 80° and 110°.

[0035] In an optional embodiment, the porous structure can be one of the following cell structures: octahedron, body-centered cubic, rhombic dodecahedron, or three-period minimal surface.

[0036] The femoral prosthesis of the hip joint is made of zirconium-niobium alloy as raw material and is integrally formed by electron beam melting (EBM) 3D printing technology.

[0037] The prosthesis parts formed by EBM are subjected to high-temperature oxidation technology to form a zirconia ceramic layer on the surface of the prosthesis, which gives it excellent wear resistance and friction reduction properties, while further improving the biocompatibility of the prosthesis.

[0038] The prosthesis is made of zirconium-niobium alloy, a material with excellent biocompatibility and mechanical properties, ensuring long-term safety and reliability. The prosthesis is manufactured using electron beam melting additive manufacturing to achieve integrated forming of the porous and solid structures, followed by a high-temperature oxidation process to form a uniform and dense zirconium oxide ceramic layer on the surface. This ceramic layer possesses excellent wear resistance and friction-reducing properties, significantly reducing joint friction and wear, extending prosthesis lifespan, and minimizing loosening and failure due to wear.

[0039] The femoral prosthesis of the hip joint provided by the present invention has multiple anti-rotation keels 400 on the inner surface of the ball joint portion 100 of the femoral prosthesis body. The anti-rotation keels 400 can effectively improve the anti-rotation effect of the femoral prosthesis. Moreover, the anti-rotation keels 400 make the porous structure of the multiple outer regions formed on the inner surface have different pore sizes, that is, each outer region corresponds to a different bone density region of the femoral head section, which solves the problem of prosthesis loosening caused by biomechanical mismatch between the prosthesis and the host bone.

[0040] Hip joint femoral prostheses have excellent osseointegration, biomechanical adaptability, and wear resistance, as well as good biocompatibility, which can significantly extend the service life of the prosthesis and have high clinical application value.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A hip femoral prosthesis, characterized in that, The femoral prosthesis body comprises a spherical joint part (100) and a connecting part (300), the spherical joint part (100) has an opening, the connecting part (300) is inserted from the opening and connected inside the spherical joint part (100); The inner surface of the spherical joint part (100) is provided with a porous structure layer (200), a plurality of anti-rotation keels (400) are arranged on the inner surface of the spherical joint part (100), the plurality of anti-rotation keels (400) are arranged along the circumference of the connecting part (300), and the plurality of anti-rotation keels (400) divide the inner surface of the spherical joint part (100) into a plurality of outer regions, and the pore diameters of the porous structures of adjacent outer regions are different.

2. The hip femoral prosthesis according to claim 1, characterized in that, An inner region (900) is formed on the circumferential side of the connecting part (300) of the inner surface of the spherical joint part (100), and the plurality of outer regions are distributed on the circumferential side of the inner region (900).

3. The hip femoral prosthesis according to claim 2, characterized in that, The inner surface of the spherical joint part (100) is provided with four anti-rotation keels (400), and the anti-rotation keels (400) are connected with the spherical joint part (100) through the porous structure layer (200); The anti-rotation keels (400) divide the inner surface of the spherical joint part (100) into four outer regions, and the four outer regions are respectively a first outer region (500), a second outer region (600), a third outer region (700) and a fourth outer region (800); The first outer region (500) and the fourth outer region (800) are arranged on both sides of the connecting part (300), and the second outer region (600) and the third outer region (700) are arranged on both sides of the connecting part (300).

4. The hip femoral prosthesis according to claim 3, characterized in that, The pore diameter of the first outer region (500) is 0.18mm-0.28mm, and the porosity is 55%-65%.

5. The hip femoral prosthesis according to claim 3, characterized in that, The pore diameter of the second outer region (600) and the third outer region (700) is 0.28mm-0.38mm, and the porosity is 66%-75%.

6. The hip femoral prosthesis according to claim 3, characterized in that, The pore diameter of the fourth outer region (800) and the inner region (900) is 0.36mm-0.65mm, and the porosity is 76%-85%.

7. The hip femoral prosthesis according to claim 6, characterized in that, The anti-rotation keel (400) protrudes 1mm-3mm from the surface of the porous structure layer (200), and the width of the anti-rotation keel (400) is 1mm-4mm.

8. The hip femoral prosthesis of claim 2, wherein, The outer diameter of the inner region (900) is 12mm-24mm.

9. The hip femoral prosthesis according to claim 1, characterized in that, The outer region is a sector, and the central angle of the outer region is 80°-110°.

10. The hip femoral prosthesis of claim 1 wherein, The porous structure is one of a cubic cell structure of an octahedron, a body-centered cubic, a rhombic dodecahedron, and a three-period minimal surface.

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