Femoral head prosthesis

Abstract

The application belongs to the technical field of femoral head repair, and discloses a femoral head prosthesis, which comprises a planting screw, a prosthesis body and a filling body. The planting screw is arranged in the femoral head and used for fixing the prosthesis body of the femoral head prosthesis. One side surface of the prosthesis body is used for repairing the bone cortex surface of the femoral head and contacting with the acetabulum. The other side of the prosthesis body is connected with the planting screw through a combined press-fit structure. The combined press-fit structure comprises a first plug-in part and a second plug-in part in interference fit. The first plug-in part is arranged on the side surface of the prosthesis body in contact with the planting screw, and the second plug-in part is arranged on the planting screw. The filling body is connected to the side of the prosthesis body away from the acetabulum and used for filling the cancellous bone part of the femoral head defect. The filling body is composed of a microporous structure. The femoral head prosthesis has the advantages of good fixing effect, long service life and convenient installation.

Description

Technical Field

[0001] This invention relates to the field of femoral head repair technology, and more particularly to a femoral head prosthesis. Background Technology

[0002] Avascular necrosis of the femoral head (ONFH) is a refractory and progressive osteoarthritis that severely affects the function of the affected limb and reduces the quality of life for patients.

[0003] Treatment for ONFH (avascular necrosis of the femoral head) is mainly divided into two categories: drug therapy and surgical treatment. These include core decompression, free fibular grafting, femoral head replacement, and total hip arthroplasty. In stages I and II of ONFH, core decompression or free fibular grafting is generally used. While these methods show significant short-term effects, long-term follow-up results are often unsatisfactory, and further necrosis and collapse of the femoral head are possible. Total hip arthroplasty is suitable for patients with advanced ONFH, offering ideal surgical outcomes. However, the lifespan of the prosthesis is generally only 15-20 years. Therefore, young patients undergoing total hip replacement prematurely may face revision surgery in old age. Compared to primary replacement, revision surgery is more difficult, longer, involves more bleeding, and carries a higher risk of infection. It also demands higher surgical skills, and often fails to achieve the same results as the primary replacement. It is prone to catastrophic complications such as infection and dislocation, requiring even more complex revision surgeries, severely impacting the patient's quality of life. The high costs place a heavy burden on both the individual patient and society.

[0004] Currently, prostheses made of biocompatible or metallic materials are commonly used to replace damaged or collapsed joint surfaces. This effectively relieves joint pain, restores hip joint function to the greatest extent possible, preserves as much hip bone as possible, and delays or avoids total hip replacement. However, existing prostheses have drawbacks such as poor fixation and inconvenient installation, and significantly increase the risk of secondary femoral head collapse. Once secondary femoral head collapse occurs early, total hip replacement surgery is required, causing more extensive damage to the patient. Summary of the Invention

[0005] The purpose of this invention is to provide a femoral head prosthesis that has good fixation, is not prone to loosening, is easy to install, and has a long service life.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] Femoral head prostheses, including:

[0008] The implant screw is configured to be inserted into the femoral head;

[0009] The prosthesis body has one side surface used to repair the cortical surface of the femoral head and to contact the acetabulum. The other side of the prosthesis body is connected to the implant screw through a combined press-fit structure. The combined press-fit structure includes an interference fit first insertion part and a second insertion part. The first insertion part is disposed on the side of the prosthesis body that contacts the implant screw, and the second insertion part is disposed on the implant screw.

[0010] A filler, connected to the side of the prosthesis body opposite to the acetabulum, is used to fill the cancellous bone portion of the defective femoral head, and the filler is composed of a microporous structure.

[0011] As an alternative to the femoral head prosthesis provided by the present invention, one of the first insertion part and the second insertion part is a boss and the other is a slot, and the boss is inserted into the slot.

[0012] As an alternative to the femoral head prosthesis provided by the present invention, the prosthesis body further includes an arcuate portion and a connecting portion. The outer surface of the arcuate portion contacts the acetabulum. The connecting portion is located at the inner center of the arcuate portion. The end of the connecting portion opposite to the arcuate portion is connected to the boss. The implant screw has the slot.

[0013] As an alternative to the femoral head prosthesis provided by the present invention, along the direction away from the connecting portion, the side of the boss gradually approaches the central axis of the boss, and the sidewall of the slot is set as an inclined surface corresponding to the boss.

[0014] As an alternative to the femoral head prosthesis provided by the present invention, the inclined angle of the inclined surface relative to the central axis of the slot is 1-10°.

[0015] As an alternative to the femoral head prosthesis provided by the present invention, the cross-section of the boss is a non-circular cross-section, and the sidewall of the slot is provided with an abutment surface corresponding to the side of the boss to restrict the rotation of the boss relative to the slot.

[0016] As an alternative embodiment of the femoral head prosthesis provided by the present invention, the boss includes multiple abutment segments. Along the direction away from the connecting portion, the cross-sectional area of ​​the multiple abutment segments decreases sequentially. The sidewall of the slot is provided with multiple abutment surfaces corresponding to the sides of the multiple abutment segments to restrict the boss from rotating relative to the slot.

[0017] As an alternative to the femoral head prosthesis provided by the present invention, at least one of the abutment segments has a non-circular cross-section.

[0018] As an alternative to the femoral head prosthesis provided by the present invention, the central angle opposite to the arc surface of the arc portion is 20-160°.

[0019] As an alternative to the femoral head prosthesis provided by the present invention, the microporous structure includes a plurality of interconnected micropores, the pore diameter of which is 300-800 μm.

[0020] The beneficial effects of this invention are:

[0021] The femoral head prosthesis provided by this invention includes an implant screw, a prosthesis body, and a filler. The femoral head prosthesis is stably fixed to the femoral head by the implant screw, preventing loosening and improving the fixation effect. The prosthesis body is connected to the implant screw via an interference-fit first and second insertion portion. The first insertion portion is located on the side of the prosthesis body that contacts the implant screw, and the second insertion portion is located on the implant screw, effectively improving the convenience of surgical installation. One surface of the prosthesis body contacts the acetabulum and is used to repair the cortical bone surface of the femoral head. The filler is connected to the side of the prosthesis body away from the acetabulum. The filler has a microporous structure and is used to fill the cancellous bone portion of the femoral head defect. In other words, the microporous structure of the filler simulates the porous structure of trabecular bone, inducing bone ingrowth, promoting effective integration of the femoral head prosthesis with the patient's femoral head, enhancing the reliability of the connection between the femoral head prosthesis and the femoral head, facilitating long-term biological fixation, and thus extending the service life of the femoral head prosthesis. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of the present invention and these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the femoral head prosthesis provided in Embodiment 1 of the present invention during use;

[0024] Figure 2 This is a schematic diagram of the femoral head prosthesis provided in Embodiment 1 of the present invention;

[0025] Figure 3 This is an exploded view of the femoral head prosthesis provided in Embodiment 1 of the present invention;

[0026] Figure 4 This is a schematic diagram of the structure of the prosthesis body and the filler provided in Embodiment 1 of the present invention;

[0027] Figure 5 yes Figure 4 Sectional view along the middle AA direction;

[0028] Figure 6This is an exploded view of the femoral head prosthesis provided in Embodiment 2 of the present invention;

[0029] Figure 7 This is a schematic diagram of the structure of the prosthesis body and the filler provided in Embodiment 2 of the present invention;

[0030] Figure 8 yes Figure 7 Sectional view along the BB direction;

[0031] Figure 9 This is an exploded view of the femoral head prosthesis provided in Embodiment 3 of the present invention;

[0032] Figure 10 This is a schematic diagram of the structure of the prosthesis body and the filler provided in Embodiment 3 of the present invention;

[0033] Figure 11 yes Figure 10 A cross-sectional view along the CC direction;

[0034] Figure 12 yes Figure 10 A sectional view along the DD direction.

[0035] In the picture:

[0036] 100. Femoral head;

[0037] 1. Planting screw; 11. Slot;

[0038] 2. Prosthesis body; 21. Protrusion; 22. Curved surface; 23. Connecting part;

[0039] 3. Filler. Detailed Implementation

[0040] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0042] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0043] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0044] In the description of this invention, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," 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 invention is in use. They are used only for the convenience of describing the invention and for 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 the invention. Furthermore, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0045] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set" and "connection" 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. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0046] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0047] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0048] Example 1

[0049] This embodiment provides a femoral head prosthesis that, by replacing the damaged and collapsed joint surface, alleviates joint pain and restores hip joint function to the greatest extent possible. Specifically, as shown... Figure 1 and Figure 2 As shown, the femoral head prosthesis includes an implant screw 1, a prosthesis body 2, and a filler 3.

[0050] The implant screw 1 is configured to be inserted into the femoral head 100 to fix the prosthesis body 2 of the femoral head prosthesis. It is understood that the outer surface of the implant screw 1 is threaded; by screwing the implant screw 1 into the cancellous bone, the femoral head prosthesis can be firmly fixed to the patient's femoral head 100, preventing loosening and improving fixation effectiveness. One side surface of the prosthesis body 2 contacts the acetabulum to repair the cortical bone surface of the femoral head. The filler 3 is connected to the side of the prosthesis body 2 away from the acetabulum. The filler 3 is composed of a microporous structure and is used to fill the cancellous bone defect of the femoral head. In other words, the microporous structure of the filler 3 simulates the porous structure of trabecular bone, which can induce bone ingrowth, promote effective integration of the femoral head prosthesis with the patient's femoral head 100, enhance the connection reliability between the femoral head prosthesis and the femoral head 100, facilitate long-term biological fixation, and thus extend the service life of the femoral head prosthesis. The other side of the prosthesis body 2 is connected to the implant screw 1 via a combined press-fit structure. The combined press-fit structure includes a first insertion part and a second insertion part that are interference-fitted. The first insertion part is located on the side of the prosthesis body 2 that contacts the implant screw 1, and the second insertion part is located on the implant screw 1. The prosthesis body 2 and the implant screw 1 are connected by an interference fit, which simplifies the installation process and effectively improves the convenience of surgical installation.

[0051] Optionally, one of the first and second insertion parts is a boss 21, and the other is a slot 11, with the boss 21 inserted into the slot 11. The boss 21 and the slot 11 enable a detachable connection between the prosthesis body 2 and the implant screw 1, simplifying the installation process.

[0052] Specifically, such as Figure 1 As shown, in this embodiment, the prosthesis body 2 further includes an arcuate surface 22 and a connecting portion 23. The outer surface of the arcuate surface 22 contacts the acetabulum. The outer surface of the arcuate surface 22 can be a spherical arcuate surface or other arcuate surface that matches the shape of the femoral head 100 at the affected site. Preferably, the central angle subtended by the arcuate surface 22 is 20-160°. The outer surface of the arcuate surface 22 is polished smooth to reduce friction and wear, improve comfort and service life. The connecting portion 23 is located at the inner center of the arcuate surface 22. The connecting portion 23 is cylindrical, and the end of the connecting portion 23 opposite to the arcuate surface 22 is connected to the aforementioned boss 21. The slot 11 is formed on the implant screw 1.

[0053] More specifically, along the direction away from the connecting part 23, the side of the boss 21 gradually approaches the central axis of the boss 21, and the side wall of the slot 11 is set as an inclined surface corresponding to the boss 21. Further, the inclination angle of this inclined surface relative to the central axis of the slot 11 is 1-10°. That is to say, in this embodiment, both the boss 21 and the slot 11 are made with a Morse taper. The taper is small and has a self-locking characteristic. The boss 21 and the implant screw 1 can generate a large friction force to help fix it. The side of the boss 21 and the side wall of the slot 11 fit tightly and there is no relative displacement between them, so the prosthesis body 2 will not fall out of the implant screw 1.

[0054] Optionally, such as Figures 3-5 As shown, the cross-section of the boss 21 is a non-circular cross-section, and the sidewall of the slot 11 is provided with an abutment surface corresponding to the side of the boss 21 to restrict the rotation of the boss 21 relative to the slot 11. It is understood that after the cylindrical or frustum-shaped boss 21 is inserted into the slot 11, it may rotate relative to the slot 11 as the patient moves, which may lead to the failure of the femoral head prosthesis. In this embodiment, the cross-section of the boss 21 is a non-circular cross-section, that is, the cross-section of the boss 21 can be, but is not limited to, elliptical, triangular, square, or other polygonal shapes, or other cross-sectional shapes composed of curves and straight lines. These cross-sectional shapes of the boss 21, and the slot 11 that matches the cross-sectional shape of the boss 21, can all play an anti-rotation and anti-rotation role, thereby preventing relative rotation between the prosthesis body 2 and the implant screw 1, which would affect the use effect and service life of the femoral head prosthesis.

[0055] Specifically, see Figure 4 and Figure 5 In this embodiment, the cross-section of the boss 21 is a closed plane formed by an arc greater than a semicircle and a straight line. The shape of the slot 11 is adapted to the cross-section of the boss 21. The arc surface of the boss 21 has low frictional resistance when inserted into the slot 11. The plane of the boss 21 can serve as a positioning plane to prevent relative rotation between the prosthesis body 2 and the implant screw 1, thereby further improving the reliability and stability of the connection between the prosthesis body 2 and the implant screw 1.

[0056] Optionally, see [link to relevant documentation] Figure 1 The length of the boss 21 is less than the depth of the slot 11, and the distance between the bottom of the boss 21 and the bottom of the slot 11 is 0.5-2mm. When the boss 21 is inserted into the slot 11, there is a press-fit gap between the bottom of the boss 21 and the bottom of the slot 11. When the femoral head prosthesis is installed on the patient's femoral head 100, this press-fit gap can provide space for the axial micro-deformation of the boss 21 as the patient moves.

[0057] Optionally, such as Figure 1As shown, the microporous structure of the filler 3 includes multiple interconnected micropores with a pore size of 300-800 μm. In this embodiment, the filler 3 is connected to the inner side of the curved surface 22 of the prosthesis body 2 and is arranged around the outside of the connecting portion 23. Along the direction away from the curved surface 22, the side of the filler 3 gradually approaches the central axis of the connecting portion 23 until it fits against the side of the connecting portion 23. That is, the axial section of the filler 3 is an inverted conical structure. With the above arrangement, the femoral head 100 prosthesis can be more easily installed on the patient's head. At the same time, the micropores of the filler 3 can simulate the porous structure of bone trabeculae. After the femoral head 100 prosthesis is implanted in the body, blood vessels and new bone can grow into these micropores after a certain period of time, ensuring the long-term stability of the femoral head 100 prosthesis and improving its service life.

[0058] Optionally, the prosthesis body 1 and the filler 3 are integrally molded structures, ensuring the integrity of the prosthesis body 1 and the filler 3, and possessing high structural strength. For example, they can be manufactured using 3D printing technology, which not only offers high production efficiency but also guarantees processing precision.

[0059] Example 2

[0060] like Figures 6-8 As shown, this embodiment provides a femoral head prosthesis, which is basically the same as the femoral head prosthesis provided in Embodiment 1. The difference between this embodiment and Embodiment 1 is that in this embodiment, the cross-section of the boss 21 is a regular hexagon. Correspondingly, the cross-section of the slot 11 is the same as the cross-section of the boss 21. The six sides of the regular hexagon can all play a role in preventing relative rotation between the prosthesis body 2 and the implant screw 1.

[0061] Example 3

[0062] like Figures 9-12As shown, this embodiment provides a femoral head prosthesis, which is basically the same as the femoral head prosthesis provided in Embodiment 1. The difference between this embodiment and Embodiment 1 is that in this embodiment, the boss 21 includes multiple abutment sections. Along the direction away from the connecting portion 23, the cross-sectional area of ​​the multiple abutment sections decreases sequentially to facilitate the smooth assembly of the boss 21 and the slot 11. The sidewall of the slot 11 is provided with multiple abutment surfaces corresponding to the sides of the multiple abutment sections to restrict the rotation of the boss 21 relative to the slot 11. Specifically, at least one abutment section has a non-circular cross-section. Exemplarily, the boss 21 in this embodiment includes two abutment sections, which are the first abutment section and the second abutment section, respectively, along the direction away from the connecting portion 23. The cross-section of the first abutment section is circular, and the cross-section of the second abutment section is regular hexagonal, with the regular hexagon at the top of the second abutment section inscribed in the circle at the bottom of the first abutment section. The first abutment section can enhance the connection strength between the prosthesis body 2 and the implant screw 1, and the six sides of the second abutment section are used to prevent relative rotation between the prosthesis body 2 and the implant screw 1.

[0063] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A femoral head prosthesis, characterized in that, include: An implant screw (1) is configured to be inserted into the femoral head (100); The prosthesis body (2) has one side surface used to repair the cortical surface of the femoral head and to contact the acetabulum. The other side of the prosthesis body (2) is connected to the implant screw (1) through a combined press-fit structure. The combined press-fit structure includes an interference fit first insertion part and a second insertion part. The first insertion part is located on the side of the prosthesis body (2) that contacts the implant screw (1), and the second insertion part is located on the implant screw (1). The filler (3) is connected to the side of the prosthesis body (2) away from the acetabulum and is used to fill the cancellous bone portion of the defect in the femoral head. The filler (3) is composed of a microporous structure. One of the first and second plug-in parts is a boss (21), and the other is a slot (11). The boss (21) is inserted into the slot (11). Both the boss (21) and the slot (11) are made with Morse taper. The prosthesis body (2) also includes an arc-shaped part (22) and a connecting part (23). The outer surface of the arc-shaped part (22) contacts the acetabulum. The connecting part (23) is located at the inner center of the arc-shaped part (22). The end of the connecting part (23) away from the arc-shaped part (22) is connected to the boss (21). The implant screw (1) is provided with the slot (11). The filler (3) is connected to the inner side of the arcuate part (22) of the prosthesis body (2) and is arranged around the outside of the connecting part (23); along the direction away from the arcuate part (22), the side of the filler (3) gradually approaches the central axis of the connecting part (23) until it fits against the side of the connecting part (23).

2. The femoral head prosthesis according to claim 1, characterized in that, Along the direction away from the connecting part (23), the side of the boss (21) gradually approaches the central axis of the boss (21), and the side wall of the slot (11) is set as an inclined surface corresponding to the boss (21).

3. The femoral head prosthesis according to claim 2, characterized in that, The angle of inclination of the inclined surface relative to the central axis of the slot (11) is 1-10°.

4. The femoral head prosthesis according to claim 1, characterized in that, The cross-section of the boss (21) is a non-circular cross-section, and the sidewall of the slot (11) is provided with an abutment surface corresponding to the side of the boss (21) to restrict the boss (21) from rotating relative to the slot (11).

5. The femoral head prosthesis according to claim 1, characterized in that, The boss (21) includes multiple abutment sections. Along the direction away from the connecting part (23), the cross-sectional area of ​​the multiple abutment sections decreases sequentially. The sidewall of the slot (11) is provided with multiple abutment surfaces corresponding to the sides of the multiple abutment sections to restrict the boss (21) from rotating relative to the slot (11).

6. The femoral head prosthesis according to claim 5, characterized in that, At least one of the abutment sections has a non-circular cross section.

7. The femoral head prosthesis according to claim 1, characterized in that, The central angle subtended by the arc surface of the arc surface (22) is 20-160°.

8. The femoral head prosthesis according to any one of claims 1-7, characterized in that, The microporous structure comprises multiple interconnected micropores, the pore size of which is 300-800 μm.

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