A low-wear knee joint replacement prosthesis

Abstract

This utility model relates to the field of knee joint prosthesis technology, and more particularly to a low-wear knee joint replacement prosthesis. The technical solution describes a replacement prosthesis comprising a femoral prosthesis body, a liner body, and a tibial support. The femoral prosthesis body includes an upper femoral prosthesis plate and a lower femoral prosthesis plate, with multiple sets of magnets disposed between the upper and lower femoral prosthesis plates. The liner body includes an upper liner plate and a lower liner plate, with upper and lower liner cavities respectively formed on their adjacent sides, and magnets are disposed within these cavities. The magnetic poles of the adjacent sides of magnets are the same. This utility model optimizes the materials used in the replacement prosthesis, avoiding wear-prone metal particles and thus preventing inflammation. Utilizing the principle of magnetic repulsion, magnetically levitated micro-gap is formed between the prosthesis components, thereby minimizing prosthesis wear and extending its service life.

Description

Technical Field

[0001] This utility model relates to the field of knee joint prosthesis technology, and in particular to a low-wear knee joint replacement prosthesis. Background Technology

[0002] Currently, knee prostheses used in clinical practice are mainly divided into five types: posterior cruciate ligament-preserving (CR), posterior stable (PS), high flexion type, unicompartmental prosthesis, and patellofemoral prosthesis, among which posterior stable type accounts for about 65% of the market share.

[0003] The prosthetic material system mostly adopts a "metal-polyethylene" composite structure: the femoral component is mainly made of cobalt-chromium-molybdenum alloy (CoCrMo), with some high-end products using ceramicized zirconia or titanium nitride surface treatment technology; the tibial support mostly uses titanium alloy (Ti6Al4V); the polyethylene liner is generally made of ultra-high molecular weight polyethylene (UHMWPE), and in recent years it has been gradually upgraded to antioxidant-treated highly cross-linked polyethylene (XLPE) and vitamin E-doped polyethylene (VEPE). The clinical lifespan of current prostheses shows significant differentiation: the 10-year survival rate of prostheses using ordinary polyethylene liners is 85%-90%, decreasing to 75%-80% after 15 years; while the 15-year survival rate of prostheses using highly cross-linked polyethylene can reach 92%-95%. However, the annual failure rate of prostheses in obese patients (BMI>30) is 2.3 times that of patients with normal weight. Wear and tear remains the core challenge limiting prosthetic lifespan, with 67% of joint replacement revision surgeries related to prosthesis wear. A single knee replacement prosthesis generates (0.5-1) × 10⁸ wear particles (0.2-10 μm in size) annually, including metal and polyethylene particles. Macrophages engulf these particles, releasing inflammatory factors such as TNF-α and IL-1β, leading to knee joint inflammation. Furthermore, these wear particles accelerate bone resorption, causing prosthesis loosening. While many studies have attempted to mitigate prosthesis wear through material improvements or prosthesis structural design—for example, using carbon fiber-reinforced polyetheretherketone (CFR-PEEK) can reduce wear by 40%-60%—and new-generation prostheses have reduced contact stress from 35 MPa to 22 MPa through optimized tibiofemoral joint surface matching (increasing contact area by 30%-50%) and restrictive design, these measures still cannot completely prevent wear particle generation. Therefore, this application proposes a structural optimization of replacement prostheses to design a low-wear knee replacement prosthesis with a long service life. Summary of the Invention

[0004] The purpose of this invention is to address the problems existing in the background technology by proposing a low-wear knee replacement prosthesis with a long service life and minimal wear.

[0005] The technical solution of this utility model is: a low-wear knee joint replacement prosthesis, the replacement prosthesis including a femoral prosthesis body, a padding body and a tibial support, the femoral prosthesis body including an upper femoral prosthesis plate and a lower femoral prosthesis plate, and multiple sets of magnets are arranged between the upper femoral prosthesis plate and the lower femoral prosthesis plate;

[0006] The pad body includes an upper pad plate and a lower pad plate. The upper pad plate and the lower pad plate are respectively provided with an upper pad cavity and a lower pad cavity on their sides that are close to each other, and a magnet is provided in the upper pad cavity and the lower pad cavity.

[0007] The magnetic poles of magnet one and magnet two are the same on the side that are close to each other.

[0008] Optionally, a snap-fit ​​assembly for connecting the upper femoral prosthesis plate and the lower femoral prosthesis plate is provided between them, and the upper liner plate and the lower liner plate are assembled and connected using the same snap-fit ​​assembly.

[0009] Optionally, the buckle assembly includes a first fixing rod and a second fixing rod. Multiple sets of the first fixing rods are respectively fixedly connected to the lower femoral prosthesis plate and the lower liner plate, and the upper femoral prosthesis plate and the upper liner plate are respectively fixedly connected to the ends of the second fixing rods.

[0010] The sides of the second fixed connecting rod and the first fixed connecting rod are respectively provided with sealing gaskets for sealing the connection between the femoral prosthesis body and the liner body.

[0011] Optionally, the lower surface of the upper femoral prosthesis plate is provided with three sets of upper mounting cavities, and a lower mounting cavity is provided on the upper surface of the lower femoral prosthesis plate at the position corresponding to the upper mounting cavity, and the magnet is fixedly installed in the lower mounting cavity.

[0012] Optionally, the upper liner plate and the lower liner plate have a mounting groove on one side of the lower liner cavity on their contact surfaces, and the maximum inner diameter of the mounting groove is greater than the maximum diameter of the second magnet.

[0013] Optionally, a sealing strip is provided within the mounting groove for sealing connection.

[0014] Optionally, the upper femoral prosthesis plate has five curved surfaces on its upper surface.

[0015] Optionally, a pad block is fixedly connected to the upper surface of the upper pad plate.

[0016] Compared with the prior art, the present invention has the following beneficial technical effects:

[0017] This invention avoids the metal particles generated by the wear of traditional metal materials by injection molding the femoral prosthesis body, the pad body, and the tibial support, thereby reducing the risk of postoperative osteolysis. Furthermore, the hardness of the polymer material is closer to that of natural articular cartilage, which is more in line with the bionic concept.

[0018] This invention utilizes the principle of "like poles repel" of magnets to create a magnetically levitated micro-gap between the femoral prosthesis body and the liner body. During joint bending, the repulsion of the magnets prevents direct contact between the prosthesis components, minimizing prosthesis wear and extending the prosthesis's lifespan.

[0019] In summary, the replacement prosthesis of this invention is optimized in terms of materials to avoid wear and tear on metal particles, thereby preventing inflammation. By utilizing the principle of magnetic repulsion between like poles, magnetic levitation micro-gap is formed between the prosthesis components, thereby minimizing prosthesis wear and extending the prosthesis's service life. Attached Figure Description

[0020] Figure 1 A three-dimensional structural schematic diagram of this utility model is provided;

[0021] Figure 2 An exploded structural diagram of this utility model is provided;

[0022] Figure 3 This is a schematic diagram of the exploded structure of the padding body;

[0023] Figure 4 This is a schematic diagram of the exploded structure of the femoral prosthesis.

[0024] Figure 5 A cross-sectional front view of the main body and the liner of the femoral prosthesis;

[0025] Figure 6 This is a schematic diagram of the buckle assembly in this utility model;

[0026] Figure 7 This is a schematic diagram illustrating the magnetic levitation principle of the femoral prosthesis body and the liner body bending at different angles.

[0027] Figure label:

[0028] 1. Femoral prosthesis body; 11. Upper femoral prosthesis plate; 110. Upper mounting cavity; 12. Lower femoral prosthesis plate; 120. Lower mounting cavity; 13. Magnet one;

[0029] 2. Gasket body; 21. Upper gasket plate; 210. Upper gasket cavity; 22. Lower gasket plate; 220. Lower gasket cavity; 221. Mounting groove; 23. Gasket stop block; 24. Magnet two; 25. Sealing strip;

[0030] 3. Tibial support;

[0031] 4. Buckle assembly; 41. Fixed connecting rod one; 42. Fixed connecting rod two; 43. Sealing gasket. Detailed Implementation

[0032] The technical solutions of this disclosure will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments.

[0033] The components of the embodiments of this disclosure, which are typically described and shown in the accompanying drawings, can be arranged and designed in a variety of different configurations. Therefore, the following detailed description of embodiments of this disclosure provided in the drawings is not intended to limit the scope of the claimed disclosure, but merely to illustrate selected embodiments of the disclosure.

[0034] Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this disclosure.

[0035] In the description of this disclosure, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this disclosure 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 disclosure.

[0036] In the description of this disclosure, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linkage" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure based on the specific circumstances.

[0037] Example

[0038] like Figures 1-5As shown, this utility model proposes a low-wear knee replacement prosthesis, which includes a femoral prosthesis body 1, a padding body 2, and a tibial support 3. The padding body 2 is located between the femoral prosthesis body 1 and the tibial support 3, and assumes the function of a natural meniscus, serving as a mechanical buffer structure. Furthermore, the parts of the padding body 2 that mate with the medial and lateral condyles of the femoral prosthesis body 1 are arc-shaped concave surfaces. Because the medial and lateral condyles of the femoral prosthesis are convex structures, the arc-shaped concave surfaces of the padding body 2 can match the convex surfaces of the femoral prosthesis condyle structure. This structure is designed to mimic the matching of the femoral condyle and meniscus structure in a normal knee joint. The femoral prosthesis body 1, the padding body 2, and the tibial support 3 are all manufactured by injection molding. The femoral prosthesis body 1 includes an upper femoral prosthesis plate 11 and a lower femoral prosthesis plate 12. The upper surface of the upper femoral prosthesis plate 11 is provided with five curved surfaces. Multiple sets of magnets 13, which are neodymium magnets, are provided between the upper femoral prosthesis plate 11 and the lower femoral prosthesis plate 12. Three sets of upper mounting cavities 110 are formed on the lower surface of the upper femoral prosthesis plate 11, and a lower mounting cavity 120 is formed on the upper surface of the lower femoral prosthesis plate 12 at the corresponding position of the upper mounting cavity 110. The magnets 13 are fixedly set in the lower mounting cavity 120. In order to maximize the magnetic field conduction, the femoral prosthesis body 1 is made of a polymer material, such as any one of polyurethane, polyetheretherketone, or ultra-high molecular weight polyethylene. In this embodiment, polyurethane injection molding is used. The femoral prosthesis body 1 is designed to mimic the structure of the femoral condyle of a normal knee joint and is an important structure for buffering the lateral stress of the femur. The medial and lateral condyle structures of the femoral prosthesis slide relative to the medial and lateral surfaces of the tibial pad, thereby realizing the bending function of the knee joint at different angles.

[0039] like Figure 6 As shown, a snap-fit ​​assembly 4 for connecting the upper femoral prosthesis plate 11 and the lower femoral prosthesis plate 12 is provided between them. The snap-fit ​​assembly 4 includes a first fixing connecting rod 41 and a second fixing connecting rod 42. Multiple sets of first fixing connecting rods 41 are fixedly connected to the lower femoral prosthesis plate 12 and the lower liner plate 22 respectively. The upper femoral prosthesis plate 11 and the upper liner plate 21 are fixedly connected to the ends of the second fixing connecting rods 42 respectively. The sides of the second fixing connecting rods 42 and the sides of the first fixing connecting rods 41 are respectively provided with sealing gaskets 43 for sealing the femoral prosthesis body 1 and the liner body 2.

[0040] like Figure 3 and Figure 5As shown, the pad body 2 includes an upper pad plate 21 and a lower pad plate 22. The upper pad plate 21 and the lower pad plate 22 are assembled with a snap-fit ​​assembly 4 to prevent the infiltration of body fluid and synovial fluid into the knee joint. A pad block 23 is fixedly connected to the upper surface of the upper pad plate 21. The side of the upper pad plate 21 that contacts the lower pad plate 22 has an installation groove 221 located on one side of the lower pad cavity 220. A sealing strip 25 is sealed inside the installation groove 221 to prevent liquid leakage. The upper pad 21 and the lower pad 22 are assembled and connected using the same snap-fit ​​assembly 4. The upper pad 21 and the lower pad 22 are respectively provided with an upper pad cavity 210 and a lower pad cavity 220 on their adjacent sides. Magnet 24 is provided in the upper pad cavity 210 and the lower pad cavity 220. Magnet 24 is a neodymium magnet. The maximum inner diameter of the mounting groove 221 is larger than the maximum diameter of magnet 24. The magnetic poles of magnet 13 and magnet 24 are the same on their adjacent sides.

[0041] In this embodiment, combined with Figure 5 As shown, after magnet 13 is installed inside the upper mounting cavity 110 and the lower mounting cavity 120, the upper femoral prosthesis plate 11 and the lower femoral prosthesis plate 12 are sealed by the snap-fit ​​assembly 4. The upper liner plate 21 and the lower liner plate 22 are sealed by installing magnet 24 in the upper liner cavity 210 and the lower liner cavity 220 and then using the snap-fit ​​assembly 4. At the same time, the sealing strip 25 can fill the magnet 24 from its hole, and then seal the filling hole with the sealing strip 25. Figure 7 As shown, when the femoral prosthesis body 1 is bent at 0 degrees, 45 degrees and 90 degrees, the magnetic poles of the side of magnet 13 and magnet 24 that are close to each other are the same, thus generating a repulsive force. As a result, the femoral prosthesis body 1 and the pad body 2 will have a levitation effect, thereby reducing contact wear.

[0042] The above specific embodiments are merely optional embodiments of this utility model. Based on the technical solution of this utility model and the relevant teachings of the above embodiments, those skilled in the art can make various alternative improvements and combinations to the above specific embodiments.

Claims

1. A low wear knee replacement prosthesis comprising a femoral prosthesis body (1), a liner body (2) and a tibial tray (3), characterized in that, The femoral prosthesis body (1) includes an upper femoral prosthesis plate (11) and a lower femoral prosthesis plate (12), and multiple sets of magnets (13) are provided between the upper femoral prosthesis plate (11) and the lower femoral prosthesis plate (12); The pad body (2) includes an upper pad plate (21) and a lower pad plate (22). The upper pad plate (21) and the lower pad plate (22) are respectively provided with an upper pad cavity (210) and a lower pad cavity (220) on their sides that are close to each other. Magnets (24) are provided in the upper pad cavity (210) and the lower pad cavity (220). The magnetic poles on the sides of magnet one (13) and magnet two (24) that are close to each other are the same.

2. A low wear knee replacement prosthesis according to claim 1, wherein, A snap-fit ​​assembly (4) for connecting the upper femoral prosthesis plate (11) and the lower femoral prosthesis plate (12) is provided between them, and the upper pad plate (21) and the lower pad plate (22) are assembled and connected using the same snap-fit ​​assembly (4).

3. A low wear knee replacement prosthesis according to claim 2, wherein, The buckle assembly (4) includes a first fixed connecting rod (41) and a second fixed connecting rod (42). Multiple sets of the first fixed connecting rods (41) are fixedly connected to the lower femoral prosthesis plate (12) and the lower pad plate (22) respectively. The upper femoral prosthesis plate (11) and the upper pad plate (21) are fixedly connected to the ends of the second fixed connecting rods (42) respectively. The sides of the second fixed connecting rod (42) and the first fixed connecting rod (41) are respectively provided with sealing gaskets (43) for sealing connection between the femoral prosthesis body (1) and the liner body (2).

4. The low wear knee replacement prosthesis of claim 1, wherein, The lower surface of the upper femoral prosthesis plate (11) is provided with three sets of upper mounting cavities (110), and a lower mounting cavity (120) is provided on the upper surface of the lower femoral prosthesis plate (12) corresponding to the position of the upper mounting cavity (110). The magnet (13) is fixedly installed in the lower mounting cavity (120).

5. The low wear knee replacement prosthesis of claim 1, wherein, The upper liner plate (21) and the lower liner plate (22) have an installation groove (221) on one side of the lower liner cavity (220) that is in contact with each other. The maximum inner diameter of the installation groove (221) is greater than the maximum diameter of the magnet (24).

6. A low wear knee replacement prosthesis according to claim 5, wherein, A sealing strip (25) is sealed inside the mounting groove (221).

7. The low wear knee replacement prosthesis of claim 1, wherein, The upper surface of the femoral prosthesis plate (11) is provided with multiple curved surfaces.

8. The low wear knee replacement prosthesis of claim 1, wherein, A pad block (23) is fixedly connected to the upper surface of the upper pad plate (21).

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