Implant and fixing structure thereof

Abstract

According to the implant and the fixing structure thereof, the width of the cross section of a fixing column of the fixing structure in the circumferential direction is not uniform, and the width of the cross section of the fixing column in the specified direction is in positive correlation with the stress of the fixing column in the specified direction; the anti-bending section coefficient of the cross section of the fixing column in the specified direction is in positive correlation with the stress of the fixing column in the specified direction. The fixing structure can be guaranteed to have enough strength and rigidity, the fixing structure and an implant can be prevented from loosening, deforming and breaking, it can be guaranteed that the whole fixing structure has the small osteotomy amount, trauma is reduced, and recovery is facilitated.

Description

Technical Field

[0001] The present invention relates to the field of implants, and particularly to an implant and its fixation structure. Background Art

[0002] Orthopedic implants are usually used to replace damaged bone tissues in the human body, and the reliability and effectiveness of their fixation to bones are important prerequisites for the success of surgery. The magnitude and direction of the forces acting on orthopedic implants in the human body are complex and irregular. Clinically, aseptic loosening is one of the main reasons for revision of orthopedic implants. To ensure the short-term and long-term success of orthopedic implants, it is crucial that the orthopedic implants can be stably and firmly fixed in the patient's body, and the fixation post is an important part of it.

[0003] The strength and stiffness of the bioactive coating of the bioactive fixation post are often small. Therefore, the strength and stiffness of the bioactive fixation post depend on its internal solid part. Especially for bioactive fixation posts that require as little bone resection as possible, the cross-section of the fixation post is relatively small, and the bioactive coating also occupies some space. Therefore, the solid part of the fixation post will be even smaller. In some cases where the force is relatively large, the situation of insufficient strength and stiffness of the bioactive fixation post is likely to occur, which may lead to loosening, deformation or even fracture of the implant, affecting bone healing and the functional recovery of the patient.

[0004] The statements herein only provide background art related to the present invention and do not necessarily constitute prior art. Summary of the Invention

[0005] The purpose of the present invention is to provide an implant and its fixation structure, which can not only ensure that the fixation structure has sufficient strength and stiffness to prevent loosening, deformation and fracture of the fixation structure and the implant, but also ensure that the overall fixation structure has a relatively small bone resection amount, reduce trauma and is conducive to recovery.

[0006] To achieve the above purpose, the present invention provides a fixation structure of an implant. The implant includes a prosthesis body and a fixation structure connecting the prosthesis body. The fixation structure includes: at least one fixation post;

[0007] The width of the cross-section of the fixation post is uneven in the circumferential direction, and the width of the cross-section in a specified direction is positively correlated with the magnitude of the force applied to the fixation post in the specified direction, that is, the flexural section modulus of the cross-section in the specified direction is positively correlated with the magnitude of the force applied to the fixation post in the specified direction.

[0008] The cross-section of the fixing post has at least a first width and a second width. The first width corresponds to a first direction, and the second width corresponds to a second direction. The force on the fixing post in the first direction is greater than the force on the fixing post in the second direction. Then the first width is greater than the second width, and the flexural section modulus of the fixing post in the first direction is greater than the flexural section modulus of the fixing post in the second direction.

[0009] The ratio of the flexural section modulus of the fixing post in the first direction to the flexural section modulus of the fixing post in the second direction is 1.01 to 100.

[0010] The first direction is the main force-bearing direction of the fixing post, the main force-bearing direction is perpendicular to the coronal plane, the second direction is the secondary force-bearing direction of the fixing post, and the secondary force-bearing direction is perpendicular to the sagittal plane.

[0011] The fixing post is made of a metal material or a plastic material.

[0012] The width of the cross-section of the fixing post is 1 mm to 50 mm.

[0013] The outer surface of the fixing post is coated with a biological coating.

[0014] The present invention also provides a unicompartmental joint implant, comprising:

[0015] A lateral femoral condyle prosthesis body or a medial femoral condyle prosthesis body, and the fixing structure is provided on the lateral femoral condyle prosthesis body or the medial femoral condyle prosthesis body;

[0016] A tibial prosthesis body, and the fixing structure is provided on the tibial prosthesis body.

[0017] The present invention also provides an implant, comprising: at least one prosthesis body, and the fixing structure is provided on the prosthesis body.

[0018] The implant at least includes: a knee joint implant, an ankle joint implant, and a dental implant.

[0019] The present invention sets the width of the cross-section of the fixing post on the implant in the direction of greater force to be larger, and sets the width of the cross-section of the fixing post in the direction of smaller force to be smaller. It can not only ensure that the fixing post has sufficient strength and stiffness, and can prevent the fixing post and the implant from loosening, deforming and breaking, but also ensure that the fixing post as a whole has a smaller osteotomy volume, reduce trauma and is conducive to recovery. Description of the Drawings

[0020] Figure 1 It is a schematic cross-sectional view of the fixing post of an existing orthopedic implant.

[0021] Figure 2a This is a schematic structural view of a unicondylar joint implant in an upright position in an embodiment of the present invention.

[0022] Figure 2b This is a schematic structural view of a unicondylar joint implant in a flexed position in an embodiment of the present invention.

[0023] Figure 3 is Figure 2a a cross-sectional view taken along line A-A of

[0024] Figure 4 is Figure 2a a cross-sectional view taken along line B-B of

[0025] Figure 5 a schematic view of the force on the fixing post.

[0026] Figures 6a to 6c a schematic cross-sectional view of the fixing post.

[0027] Figure 7 This is a schematic structural view of an implant in another embodiment of the present invention. Detailed implementation manners

[0028] The following specifically describes Figures 1 to 7 the preferred embodiments of the present invention.

[0029] The fixing post is an important component in orthopedic implants, mainly used to provide stable support to promote the healing and repair of bone tissue. The fixing post provides stable support through close connection with bone tissue, prevents displacement and misalignment of the joint part, and ensures the alignment and line of the joint. The fixing post can provide additional support and fixation to accelerate the healing process. By reducing the displacement and misalignment of the joint part, maintaining the stability of the joint end, promoting the proliferation and differentiation of bone cells, and accelerating the formation of new bone.

[0030] Biological orthopedic implants refer to those implants that can have a biological reaction with human bone tissue and promote the growth and repair of bone tissue. Such implants usually have good biocompatibility and bioactivity, and can be gradually replaced or integrated by new bone tissue in the body, thus realizing the regeneration and reconstruction of bone tissue. Biological orthopedic implants have significant advantages in terms of biocompatibility, bioactivity, mechanical properties, personalized customization, antibacterial properties, etc., making them an important choice for modern orthopedic treatment and providing a safer, more effective and comfortable treatment plan for patients.

[0031] Such as Figure 1As shown, the biological fixation post 1 includes a main post body 101 and a biological coating 102 coated on the outer surface of the main post body 101. The biological coating can promote the growth of bone cells and the ingrowth of bone tissue, improve the bonding strength between the implant and the bone tissue, achieve more stable fixation, reduce the immune response between the implant and the surrounding tissues, improve the biocompatibility of the implant, and accelerate the bone healing process by releasing bioactive components such as growth factors. The strength and stiffness of the biological coating 102 are often small, and the main post body 101 is usually made of metal or plastic, so the strength and stiffness of the biological fixation post depend on the main post body 101. Currently, the aspect ratio of the length to the width of the cross-section of the main post body 101 is usually set to be approximately equal to 1:1. This traditional design cannot take into account both the strength of the fixation post and the amount of bone resection. For the biological fixation post 1 that requires as little bone resection as possible, its overall cross-section is relatively small. Since the biological coating 102 also occupies part of the space, the cross-section of the main post body 101 will be even smaller. In some cases where the force is relatively large, especially when the forces in all directions are uneven, it will cause the implant to loosen, deform or even break, affecting bone healing and the functional recovery of the patient.

[0032] As Figure 2a and Figure 2b shown, in an embodiment of the present invention, a unicondylar joint implant is provided, which includes a unicondylar joint prosthesis body 2 and a tibial prosthesis body 3. The unicondylar joint prosthesis body 2 can be a lateral femoral condyle prosthesis body or a medial femoral condyle prosthesis body. One or more fixation posts 1 are provided on both the unicondylar joint prosthesis body 2 and the tibial prosthesis body 3. In this embodiment, a main fixation post 1-1 and an auxiliary fixation post 1-2 are provided on the unicondylar joint prosthesis body 2. The structure of the main fixation post 1-1 is the same as that of the auxiliary fixation post 1-2, and both include a main post body 101 and a biological coating 102. The size of the main fixation post 1-1 is larger than that of the auxiliary fixation post 1-2.

[0033] After the unicondylar joint implant is implanted into the knee joint, the forces on the fixation post 1 in all circumferential directions are uneven. Taking the unicondylar joint prosthesis body 2 as an example, as Figure 2b shown, when the unicondylar joint prosthesis body 2 is in the flexion position, the main fixation post 1-1 on the unicondylar joint prosthesis body 2 is mainly subjected to body weight and sliding friction, and the main force direction D of the main fixation post 1-1 is perpendicular to the axis of the main fixation post 1-1. When the unicondylar joint prosthesis body 2 is in the upright position, the main force direction D of the main fixation post 1-1 on the unicondylar joint prosthesis body 2 is perpendicular to the coronal plane, as Figure 2a and Figure 3As shown, the secondary force direction d of the main fixing column 1-1 on the unicompartmental prosthesis body 2 is perpendicular to the sagittal plane, and the force F of the main fixing column 1-1 in the main force direction D is significantly greater than the force f of the main fixing column 1-1 in the secondary force direction d.

[0034] For such fixed columns with obvious main force direction, the present invention provides a new type of fixed column structure, such as Figure 4 As shown, the fixed column 1 comprises a main column 101 and a biological coating 102 coated on the outer surface of the main column 101. The cross section of the main column 101 has at least a first width a and a second width b, the direction of the first width a corresponds to the main force direction D, and the direction of the second width b corresponds to the secondary force direction d. If the force F of the fixed column 1 in the main force direction D is greater than the force f of the fixed column 1 in the secondary force direction d, the first width a is set to be greater than the second width b, so that the bending section modulus (Section Modulus) of the fixed column 1 in the main force direction D is greater than the bending section modulus of the fixed column 1 in the secondary force direction d.

[0035] The bending section coefficient is a physical quantity used to describe the influence of the cross-sectional shape or size of a part on the force, bending moment, torque, etc. of the part. It is used to calculate the bending strength and torsional strength of parts and components, or to calculate the maximum stress on the cross section under given bending moment or torque conditions. The bending section coefficient W is defined as the moment of inertia of the cross section I z The distance y from the point on the cross section farthest from the neutral axis max The ratio of It can be seen from this that the bending section coefficient of the fixing column 1 in different force directions is positively correlated with its cross-sectional width in different force directions. The larger the width of the cross-section of the fixing column 1 in a certain force direction, the larger the bending section coefficient of the fixing column 1 in this force direction.

[0036] The present invention sets the width of the cross section of the fixing column on the unicompartmental joint implant to be larger in the direction of greater force, and sets the width of the cross section of the fixing column in the direction of less force to be smaller, which can ensure that the fixing column has sufficient strength and rigidity and prevent the fixing column and the implant from loosening, deforming and breaking, and can also ensure that the fixing column as a whole has a smaller amount of bone resection, reduce trauma and facilitate recovery.

[0037] The ratio of the bending section coefficient of the fixing column 1 in the main force direction D to the bending section coefficient of the fixing column 1 in the secondary force direction d is 1.01-100. The width of the cross section of the fixing column in the direction of greater force is set to be larger, and the width of the cross section of the fixing column in the direction of less force is set to be smaller. This can ensure that the fixing column has sufficient strength and rigidity, prevent the fixing column and the implant from loosening, deformation and breakage, and ensure that the fixing column as a whole has a smaller bone resection amount, reduce trauma and facilitate recovery.

[0038] like Figure 5 As shown, the forces on the fixing column 1 in various circumferential directions are uneven, and the forces in the main force direction D are significantly greater than those in other force directions d. 1 ~d 3 Therefore, in other embodiments of the present invention, according to the magnitude of the forces in various directions, the width of the cross section of the main column body 101 of the fixing column 1 in the circumferential direction is set to be non-uniformly distributed, so that the width of the cross section of the main column body 101 in any circumferential direction is positively correlated with the magnitude of the forces on the fixing column 1 in this direction, that is, if the force on the fixing column 1 in a certain direction is large, the width of the cross section of the main column body 101 in this direction is also large, so that the bending section coefficient of the fixing column 1 in this direction is also large, which can withstand large forces and prevent the fixing column and the implant from loosening, deforming and breaking. If the force on the fixing column 1 in a certain direction is small, the width of the cross section of the main column body 101 in this direction is also small, so that it can be ensured that the fixing column as a whole has a small amount of bone resection, reduce trauma, and facilitate recovery.

[0039] like Figures 6a to 6c As shown, according to the different magnitudes of the forces on the fixing column 1 in various circumferential directions, the width of the cross section of the main column 101 in any circumferential direction is positively correlated with the magnitude of the forces on the fixing column 1 in that direction. Finally, the cross section of the main column 101 can present various shapes, and the width of the cross section of the main column 101 in at least one direction is greater than the width in other directions. The force direction corresponding to the larger width is the main force direction of the fixing column 1. The larger width enables the fixing column 1 to have a larger bending section coefficient in the main force direction, so that it can withstand a larger force and prevent the fixing column 1 from loosening, deforming and breaking. Accordingly, the cross section of the fixing column 1 after being coated with the biological coating 102 can also present various shapes.

[0040] In one embodiment, Figure 6a As shown, the first direction D is the main force direction of the fixing column 1, and the second direction d 1 is the secondary force direction of the fixing column 1, and the forces in other directions can be ignored. The force on the fixing column 1 in the first direction D is greater than that in the second direction d1 The force on it. In this embodiment, first, the width of the cross-section of the main column 101 along the first direction D is set to be relatively large, so that the flexural section modulus of the fixing column 1 along the first direction D is relatively large, thereby bearing a relatively large force in the first direction D and preventing the fixing column 1 from loosening, deforming and breaking. Secondly, the width of the cross-section of the main column 101 along the second direction d 1 is set to be relatively small, and the width of the cross-section of the main column 101 along the second direction d 1 is set to be less than the width of the cross-section of the main column 101 along the first direction D, so that the flexural section modulus of the fixing column 1 along the second direction d 1 can bear the force in the second direction d 1 That's all. Further, the width of the cross-section of the main column 101 along other directions can be reduced to reduce the overall area of the cross-section of the main column 101, so as to ensure that the fixing column 1 as a whole has a relatively small osteotomy amount. Finally, the cross-section of the main column 101 presents a cross shape to ensure that the main column 101 has sufficient stiffness and strength in the first direction D, while the cross-section of the fixing column 1 after being coated with the biological coating 102 presents an elliptical shape to match the cross-section shape of the main column 101 as much as possible, so as to ensure that the fixing column 1 as a whole has a relatively small osteotomy amount, reduce trauma and facilitate recovery.

[0041] In another embodiment, as Figure 6b shown, the first direction D is the main force direction of the fixing column 1, and the second direction d 1 is the secondary force direction of the fixing column 1. The force on the fixing column 1 in the second direction d 1 is less than the force on it in the first direction D. The forces on the fixing column 1 in the third direction d 2 and in the fourth direction d 3 are both less than the force on it in the second direction d 1 That's all. In this embodiment, first, the width of the cross-section of the main column 101 along the first direction D is set to be relatively large, so that the flexural section modulus of the fixing column 1 along the first direction D is relatively large, thereby bearing a relatively large force in the first direction D and preventing the fixing column 1 from loosening, deforming and breaking. Secondly, the width of the cross-section of the main column 101 along the second direction d 1 is set to be relatively small, and the width of the cross-section of the main column 101 along the second direction d 1 is set to be less than the width of the cross-section of the main column 101 along the first direction D, so that the flexural section modulus of the fixing column 1 along the second direction d 1 can bear the force in the second direction d 1 That's all. Finally, the width of the cross-section of the main column 101 along the third direction d 2 and the width along the fourth direction d 3The width is set to be smaller than the cross-section of the main column 101 along the second direction d 1 so that the fixing column 1 along the third direction d 2 has a flexural section modulus that can withstand the force in the third direction d 2 and the fixing column 1 along the fourth direction d 3 has a flexural section modulus that can withstand the force in the fourth direction d 3 That's all. Finally, the cross-section of the main column 101 presents a hexagonal shape with two inscribed circles, ensuring that the main column 101 has sufficient stiffness and strength in the first direction D. After the biological coating 102 is applied, the cross-section of the fixing column 1 presents a rectangular shape to match the cross-section shape of the main column 101 as much as possible, so as to ensure that the fixing column 1 as a whole has a small osteotomy volume, reduces trauma, and is conducive to recovery.

[0042] In yet another embodiment, as Figure 6c shown, the first direction D is the main force direction of the fixing column 1, and the second direction d 1 is the secondary force direction of the fixing column 1. The force on the fixing column 1 in the second direction d 1 is less than the force in the first direction D. The force on the fixing column 1 in other directions linearly decreases from the first direction D to the second direction d 1 In this embodiment, first, the width of the cross-section of the main column 101 along the first direction D is set to be larger, so that the flexural section modulus of the fixing column 1 along the first direction D is larger, thereby withstanding the larger force in the first direction D and preventing the fixing column 1 from loosening, deforming, and breaking. Secondly, the width of the cross-section of the main column 101 along the second direction d 1 is set to be smaller, and the width of the cross-section of the main column 101 along the second direction d 1 is set to be smaller than the width of the cross-section of the main column 101 along the first direction D, so that the flexural section modulus of the fixing column 1 along the second direction d 1 can withstand the force in the second direction d 1 That's all. Finally, the width of the cross-section of the main column 101 linearly decreases from the first direction D to the second direction d 1 Finally, the cross-section of the main column 101 presents an elliptical shape, ensuring that the main column 101 has sufficient stiffness and strength in the first direction D. After the biological coating 102 is applied, the cross-section of the fixing column 1 presents a circular shape to match the cross-section shape of the main column 101 as much as possible. Even some outer surfaces of the main column 101 can be not coated with the biological coating 102 to reduce the overall cross-sectional area of the fixing column 1, so as to ensure that the fixing column 1 as a whole has a small osteotomy volume, reduces trauma, and is conducive to recovery.

[0043] In another embodiment of the present invention, as Figure 7As shown, an implant is provided, which includes at least one prosthesis body 4, and at least one fixing post 1 is arranged on the prosthesis body 4. The implant can be a knee implant, an ankle implant, a dental implant, etc. The common point of these implants is that there is an obvious main force direction after the fixing posts are implanted into the human body. For example, the main force direction of the fixing posts on the tibial tray in a knee implant is perpendicular to the coronal plane, and the main force direction of the fixing posts of the tibial component and the talar component in an ankle implant is also perpendicular to the coronal plane. Therefore, for orthopedic implants with an obvious main force direction, the fixing post structure provided by the present invention can also be adopted. The specific fixing post structure is as shown in Figure 4 and Figures 6a to 6c shown, which will not be elaborated here again.

[0044] The fixing post structure of the implant provided by the present invention is particularly suitable for slender fixing posts with a cross-sectional width of 1 mm to 50 mm. By setting the cross-sectional width of the fixing post in the direction of greater force to be larger and the cross-sectional width of the fixing post in the direction of smaller force to be smaller, it can not only ensure that the slender fixing post has sufficient strength and stiffness, and can prevent the fixing post and the implant from loosening, deforming and breaking, but also ensure that the overall fixing post has a smaller osteotomy volume, reduce trauma and facilitate recovery.

[0045] It should be noted that in the embodiments of the present invention, the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0046] In the present invention, unless otherwise clearly defined and limited, the terms "install", "connect", "connect", "fix", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0047] It should be understood that, as used in this specification and the appended claims, the term "comprising" indicates the presence of the described features, integers, steps, operations, elements, and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0048] It should also be understood that the terminology used in this specification of the present application is for the purpose of describing particular embodiments only and is not intended to limit the present application. As used in this specification of the present application and the appended claims, unless the context clearly dictates otherwise, the singular forms "a", "an", and "the" are intended to include the plural forms.

[0049] It should be further understood that the term "and / or" used in this specification of the present application and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0050] As used in this specification and the appended claims, the term "if" may be construed, depending on the context, as "when", "once", "in response to determining", or "in response to detecting". Similarly, the phrase "if determined" or "if [the described condition or event] is detected" may be construed, depending on the context, as meaning "once determined", "in response to determining", "once [the described condition or event] is detected", or "in response to detecting [the described condition or event]".

[0051] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be recognized that the above description should not be considered as a limitation of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention. After those skilled in the art have read the above content, various modifications and substitutions to the present invention will be obvious. Therefore, the scope of protection of the present invention shall be defined by the appended claims.

Claims

1. A fixing structure of an implant, the implant comprising a prosthesis body and a fixing structure connected to the prosthesis body, characterized in that: The fixing structure comprises: at least one fixing column; The width of the cross section of the fixing column in the circumferential direction is uneven, and the width of the cross section in a specified direction is positively correlated with the magnitude of the force applied to the fixing column in the specified direction, that is, the bending section coefficient of the cross section in the specified direction is positively correlated with the magnitude of the force applied to the fixing column in the specified direction.

2. The fixing structure according to claim 1, characterized in that: The cross-section of the fixing column has at least a first width and a second width, the first width corresponds to a first direction, the second width corresponds to a second direction, the force applied to the fixing column in the first direction is greater than the force applied to the fixing column in the second direction, then the first width is greater than the second width, and the bending section coefficient of the fixing column in the first direction is greater than the bending section coefficient of the fixing column in the second direction.

3. The fixing structure according to claim 2, characterized in that: A ratio of a bending resistance section coefficient of the fixing column in the first direction to a bending resistance section coefficient of the fixing column in the second direction is 1.01-100.

4. The fixing structure according to claim 2, characterized in that: The first direction is the main force direction of the fixing column, and the main force direction is perpendicular to the coronal plane. The second direction is the secondary force direction of the fixing column, and the secondary force direction is perpendicular to the sagittal plane.

5. The fixing structure according to claim 1, characterized in that: The fixing column is made of metal or plastic.

6. The fixing structure according to claim 1, characterized in that: The width of the cross section of the fixing column is 1 mm to 50 mm.

7. The fixing structure according to any one of claims 1 to 6, characterized in that: The outer surface of the fixing post is coated with a biological coating.

8. A unicompartmental implant, characterized in that: Include: A lateral femoral condyle prosthesis body or a medial femoral condyle prosthesis body, wherein the lateral femoral condyle prosthesis body or the medial femoral condyle prosthesis body has a fixing structure as described in any one of claims 1 to 7; A tibial prosthesis body having a fixing structure as claimed in any one of claims 1 to 7.

9. An implant, characterized in that It comprises: at least one prosthesis body, on which the fixing structure as described in any one of claims 1-7 is provided.

10. The implant according to claim 9, characterized in that The implants at least include: knee joint implants, ankle joint implants, and dental implants.

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