Metaphyseal patch for tibia bone defect repair

Abstract

The invention relates to a metaphyseal patch for tibia bone defect repair, which belongs to the technical field of orthopedic medical instruments, is configured and connected to a metaphyseal of a tibia, is used for supporting and fixing a prosthesis on the metaphyseal and comprises a base body, a counter bore is formed in the metaphyseal in the length direction of the tibia, and the base body is inserted into the counter bore and abuts against the inner wall of the counter bore. The basal body is embedded in the metaphysis of the tibia, the basal body is flush with the end face of the metaphysis, the basal body is of a porous structure, the porosity of the basal body in the length direction of the tibia is gradually increased in a gradient mode from the near end of the tibia to the far end of the tibia, and the porosity of the basal body in the radial direction of the tibia is gradually increased in a gradient mode from the bone cortex to the marrow cavity. And meanwhile, the matrix adopts a porous structure with bidirectional gradient porosity change, and a porous structure with self-adaptive elastic modulus is realized, so that the patch fits the elastic modulus of sclerotin in a host bone area, and stress shielding is effectively avoided while the support strength of the prosthesis structure is met.

Description

Technical Field

[0001] The invention belongs to the technical field of orthopedic medical devices, and in particular relates to a metaphyseal patch for repairing tibial bone defects. Background Art

[0002] At present, revision knee arthroplasty is often accompanied by varying degrees of metaphyseal bone defects or insufficient bone mass, which makes it difficult for the prosthesis to obtain effective support during knee joint repair. In order to solve the problem of difficult fixation of the prosthesis during revision, patches are often used to fill the bone defects of the femoral and tibial metaphyseal ends of the knee joint. The patches can form an effective match with the host bone and provide effective support and fixation for the prosthesis structure. It is an effective treatment for knee revision. The pore size range of existing patches is 410-600μm, and its elastic modulus is between cortical bone and cancellous bone.

[0003] However, studies have found that the elastic modulus of the tibia gradually decreases from the cortical bone to the medullary cavity and from the proximal end to the distal end of the tibia, and the bone density also gradually decreases from the cortical bone to the medullary cavity and from the proximal end to the distal end of the tibia. However, the currently used patches all have a uniform elastic modulus and density, which is quite different from the elastic modulus of the host bone region. It is not only difficult to meet the strength of the support prosthesis structure, but also easy to cause stress shielding. Summary of the invention

[0004] In view of this, the present invention provides a metaphyseal patch for repairing tibial bone defects to address the deficiencies in the prior art. The present invention satisfies the support strength of the prosthesis structure while effectively avoiding stress shielding.

[0005] The technical solution of the present invention is: a metaphysis patch for repairing tibial bone defects, which is configured and connected to the metaphysis of the tibia, and is used to support and fix the prosthesis on the metaphysis, including a base, a countersunk hole is opened on the metaphysis along the length direction of the tibia, the base is inserted into the countersunk hole and abuts against the inner wall thereof, the base is flush with the end face of the metaphysis, the prosthesis is fixedly connected to the base, the base is a porous structure, the porosity of the base along the length direction of the tibia increases gradually from the proximal end to the distal end of the tibia, and the porosity of the base along the radial direction of the tibia increases gradually from the bone cortex to the medullary cavity.

[0006] Preferably, the porosity of the matrix ranges from 30% to 85%.

[0007] Preferably, the porous structure of the matrix is ​​a cancellous bone trabecular structure, and the pore size range of the porous structure is 0.4 to 0.6 mm. 。

[0008] Preferably, the cancellous bone trabecular structure adopts a periodic arrangement of cubic unit cells to construct a porous structure.

[0009] Preferably, the substrate is made of tantalum metal.

[0010] Preferably, the cross section of the base is an elliptical ring, and the area of ​​the cross section gradually decreases from one end close to the prosthesis to the other end.

[0011] Preferably, it also includes: a support body, the support body is embedded in the base and fixedly connected thereto, the prosthesis abuts against the support body, an extension rod is fixedly provided on one side of the prosthesis close to the base and is parallel to the length direction of the tibia, the extension rod passes through the support body and is fixedly connected to the tibia.

[0012] Preferably, the longitudinal cross-section of the substrate includes: a stepped type, a symmetrical type and an asymmetrical type.

[0013] Preferably, when the patch is used to fill a non-inclusive metaphyseal bone defect, the outer contour of the matrix is ​​smoothly connected to the natural bone surface of the human body.

[0014] Preferably, the surface of the substrate in contact with the tibia is provided with an osteoinductive growth factor coating, an antibacterial coating and a vascular growth factor coating.

[0015] Compared with the prior art, the present invention provides a metaphysis patch for repairing tibial bone defects, which fixes the prosthesis by burying a matrix in the metaphysis of the tibia. At the same time, the matrix adopts a porous structure with a bidirectional gradient porosity change. The porosity changes gradually along the proximal-distal direction of the tibia and changes gradually along the cortical-marrow cavity direction, thereby realizing a porous structure with adaptive elastic modulus, so that the patch fits the elastic modulus of the bone in the host bone area, meeting the support strength of the prosthesis structure while effectively avoiding stress shielding. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of the symmetrical metaphyseal patch of the present invention;

[0017] Figure 2 It is a schematic diagram of the structure of the stepped epiphyseal patch of the present invention;

[0018] Figure 3 It is a schematic diagram of the installation of the symmetrical metaphyseal patch of the present invention;

[0019] Figure 4 It is a schematic diagram of the installation of the stepped metaphyseal patch of the present invention;

[0020] Figure 5 It is a schematic diagram of the installation of the symmetrical metaphyseal patch of the present invention for non-contained bone defects;

[0021] Figure 6It is a front view of the symmetrical metaphyseal patch of the present invention;

[0022] Figure 7 is a side view of the symmetrical metaphyseal patch of the present invention;

[0023] Figure 8 is a cross-sectional view of the symmetrical metaphyseal patch of the present invention;

[0024] Fig. 9 It is a front view of the stepped metaphyseal patch of the present invention;

[0025] Fig.10 is a side view of the stepped metaphyseal patch of the present invention;

[0026] Fig.11 is a cross-sectional view of the stepped metaphyseal patch of the present invention;

[0027] Fig.12 It is a schematic diagram of the porosity change of the symmetrical metaphyseal patch of the present invention along the direction of the bone cortex-marrow cavity;

[0028] Fig.13 It is a schematic diagram of the porosity change of the symmetrical metaphyseal patch of the present invention along the proximal-distal direction of the tibia;

[0029] Fig.14 It is a schematic diagram of the porosity change of the stepped metaphyseal patch along the bone cortex-marrow cavity direction of the present invention;

[0030] Fig.15 It is a schematic diagram of the porosity change of the stepped metaphyseal patch of the present invention along the proximal-distal direction of the tibia. DETAILED DESCRIPTION

[0031] The present invention provides a metaphyseal patch for repairing tibial bone defects. Figures 1 to 15 The present invention is described with reference to the structural schematic diagram of FIG.

[0032] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the technical solutions of the present invention and simplifying the description, and do not indicate or imply 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 on the present invention.

[0033] At present, revision knee arthroplasty is often accompanied by varying degrees of metaphyseal bone defects or insufficient bone mass, which makes it difficult for the prosthesis to obtain effective support during knee joint repair. In order to solve the problem of difficult fixation of the prosthesis during revision, patches are often used to fill the bone defects of the femoral and tibial metaphyseal ends of the knee joint. The patches can form an effective match with the host bone and provide effective support and fixation for the prosthesis structure. It is an effective treatment for knee revision. The pore size range of existing patches is 410-600μm, and its elastic modulus is between cortical bone and cancellous bone.

[0034] However, studies have found that the elastic modulus of the tibia gradually decreases from the cortical bone to the medullary cavity and from the proximal end to the distal end of the tibia, and the bone density also gradually decreases from the cortical bone to the medullary cavity and from the proximal end to the distal end of the tibia. However, the currently used patches all have a uniform elastic modulus and density, which is quite different from the elastic modulus of the host bone region. It is not only difficult to meet the strength of the support prosthesis structure, but also easy to cause stress shielding.

[0035] Based on the above problems, an embodiment of the present invention provides an epiphyseal patch for repairing tibial bone defects. The prosthesis is fixed by burying a matrix in the epiphyseal end of the tibia. At the same time, the matrix adopts a porous structure with a bidirectional gradient porosity change. The porosity changes gradually along the proximal-distal direction of the tibia and changes gradually along the cortical-marrow cavity direction. A porous structure with adaptive elastic modulus is achieved, so that the patch fits the elastic modulus of the bone in the host bone area, thereby meeting the support strength of the prosthesis structure and effectively avoiding stress shielding.

[0036] As shown in the figure, Figure 3 The symmetrical metaphysis patch of this embodiment is an installation diagram of a metaphysis patch for repairing tibial bone defects, which is configured to be connected to the metaphysis of the tibia 5 and is used to support and fix the prosthesis 3 on the metaphysis. It includes a base 1, a countersunk hole is opened on the metaphysis along the length direction of the tibia 5, the base 1 is inserted into the countersunk hole and abuts against the inner wall thereof, the base 1 is flush with the end surface of the metaphysis, the prosthesis 3 is fixedly connected to the base 1, and the base 1 is a porous structure, such as Fig.13 FIG. 1 is a schematic diagram of the porosity variation of the symmetrical metaphyseal patch along the proximal-distal direction of the tibia. The porosity of the matrix 1 along the length direction of the tibia 5 increases gradually from the proximal end to the distal end of the tibia 5 (the porosity increases from 13 to 14). Fig.12 Schematic diagram of the porosity variation of the symmetrical metaphyseal patch along the direction of the bone cortex-marrow cavity. The porosity of the matrix 1 along the radial direction of the tibia 5 increases gradually from the bone cortex to the marrow cavity (the porosity increases from 11 to 12).

[0037] The porosity of the matrix 1 disclosed in this embodiment can be designed according to the bone density distribution law of the filling part to conform to the porosity distribution of the cortical bone and cancellous bone of normal bone tissue, thereby realizing a porous structure with adaptive elastic modulus, effectively avoiding stress shielding and providing reliable support for the prosthesis 3.

[0038] The base 1 in this embodiment is press-fitted and fixed to the bone bed. Before the press-fitting and fixation, a conical hammer is used to cut and form a countersink on the epiphyseal end of the tibia 5. The type of the conical hammer is continuously changed to make the countersink larger, and finally the base 1 is fixed with the countersink. The base 1 supports the prosthesis 3 of the tibia and is connected and fixed to the prosthesis 3 through bone cement.

[0039] As a further optimization solution, in this embodiment, the porosity of the substrate 1 ranges from 30% to 85%.

[0040] In the present embodiment, the porosity of the porous structure of the matrix 1 changes in a bidirectional gradient, showing a gradual and increasing gradient change along the proximal-distal direction of the tibia, with a porosity range of 30% to 85%, and a gradual and increasing gradient change along the bone cortex-marrow cavity direction, with a porosity range of 30% to 85%. The elastic modulus changes in the range of approximately 0.337 GPa to 6 GPa, which is between cancellous bone (0.1 to 0.5 GPa) and cortical bone (12 to 18 GPa). The specific porosity change needs to be designed according to the bone density distribution law of the filling part to conform to the porosity distribution of cortical bone and cancellous bone of normal bone tissue, to achieve a porous structure with adaptive elastic modulus, and to further effectively avoid stress shielding.

[0041] As a further optimization solution, in this embodiment, the porous structure of the matrix 1 is a cancellous bone trabecular structure, and the pore size range of the porous structure is 0.4-0.6 mm.

[0042] The patch matrix 1 in this embodiment is a cancellous bone trabecular structure, which can promote the growth of bone tissue and fibrous tissue and provide a structural support for bone ingrowth.

[0043] In this embodiment, the maximum pore size of the porous structure of the patch matrix 1 is 0.4-0.6 mm, which is a reasonable size for bone tissue ingrowth.

[0044] As a further optimization scheme, in this embodiment, the cancellous bone trabecula structure adopts a periodic arrangement of cubic unit cells to construct a porous structure.

[0045] As a further optimization solution, in this embodiment, the material of the substrate 1 is tantalum metal.

[0046] The material of the substrate 1 in this embodiment is tantalum metal, and porous tantalum has good biocompatibility.

[0047] like Figure 6FIG. 1 is a front view of the symmetrical metaphyseal patch of this embodiment. Figure 7 is a side view of the symmetrical metaphyseal patch of this embodiment, Figure 8 This is a cross-sectional view of the symmetrical metaphyseal patch of this embodiment. As a further optimization solution, in this embodiment, the cross section of the base 1 is an elliptical ring, and the area of ​​the cross section gradually decreases from one end close to the prosthesis 3 to the other end.

[0048] In this embodiment, the cross-section of the base 1 is designed to be an elliptical ring, so that when the base 1 is fixed to the autologous bone (medullary cavity) by press-fitting, the elliptical ring cross-section helps to achieve initial stability, and stability is achieved by bone ingrowth in the later stage. The cross-sectional area gradually decreases from the proximal end to the distal end of the tibia (similar to a cone), so that the base 1 can fit the normal bone shape.

[0049] As a further optimization scheme, the present embodiment also includes: a support body, the support body is embedded in the base body 1 and fixedly connected thereto, the prosthesis 3 abuts against the support body, an extension rod 4 is fixedly provided on the side of the prosthesis 3 close to the base body 1 and is parallel to the length direction of the tibia 5, and the extension rod 4 passes through the support body and is fixedly connected to the tibia 5.

[0050] In this embodiment, the support body is arranged along the inner surface of the substrate 1 and adapted to its shape, and can provide support for the substrate 1. The overall structure of the epiphyseal patch composed of the substrate 1 and the support body can be printed in an integrated manner using 3D printing technology, which is convenient for realizing bidirectional gradient pores and complex geometric surfaces. A through hole is provided on the support body, and the extension rod 4 passes through the through hole and abuts against its inner wall.

[0051] In this embodiment, the extension rod 4 extends into the medullary cavity and is fixedly connected to the tibia 5.

[0052] In addition, the structural parameters of the support body depend on the strength of the inner side of the substrate 1, and are intended to provide necessary support for the substrate 1. When the inner side of the substrate 1 has sufficient strength, the inner side of the substrate 1 may not include a support body. When the inner side of the substrate 1 does not use a support body, the substrate 1 itself has a through hole, and the extension rod 4 passes through the through hole on the substrate 1.

[0053] The support body in this embodiment is a low-porosity porous structure, so that the support body provides necessary support for the matrix 1 and the prosthesis 3 .

[0054] As shown in the figure, Figure 1 is a schematic diagram of the symmetrical metaphyseal patch structure of this embodiment, Figure 2 Schematic diagram of the stepped metaphyseal patch structure of this embodiment. As a further optimization solution, in this embodiment, the longitudinal cross-section of the base 1 includes: stepped type, symmetrical type and asymmetrical type.

[0055] The base 1 disclosed in this embodiment can be used in various structural types such as stepped, symmetrical, and asymmetrical according to the scope and characteristics of the bone defect. Figure 4 , which is a schematic diagram of the installation of the stepped metaphyseal patch of this embodiment. The metaphyseal patch can be designed into a series of products of different specifications and models according to the scope and characteristics of the bone defect.

[0056] When the metaphyseal patch is stepped, Fig. 9 FIG. 2 is a front view of the stepped metaphyseal patch of this embodiment. Fig.10 is a side view of the stepped metaphyseal patch of this embodiment, Fig.11 4 is a cross-sectional view of the stepped metaphyseal patch of this embodiment.

[0057] When the metaphyseal patch is stepped, Fig.14 FIG. 1 is a schematic diagram showing the porosity variation of the stepped metaphyseal patch in the present embodiment along the direction of the bone cortex-marrow cavity (the porosity increases from 11 to 12). Fig.15 Schematic diagram of the porosity variation of the stepped metaphyseal patch along the proximal-distal direction of the tibia in this embodiment (the porosity increases from 13 to 14).

[0058] The metaphyseal patch disclosed in the aforementioned embodiment is used for inclusive bone defects, and its side profile is simplified to a cone. When used for non-inclusive metaphyseal bone defects, the metaphyseal patch needs to provide a good environment for the soft tissue.

[0059] like Figure 5 This is a schematic diagram of the installation of the symmetrical epiphyseal patch of this embodiment for non-inclusive bone defects. Based on this, this embodiment proposes a solution. When the patch is used to fill the non-inclusive epiphyseal bone defect, the outer contour of the base 1 is smoothly connected to the natural bone surface of the human body.

[0060] The base 1 in this embodiment is designed based on the anatomical shape near the natural tibial metaphysis and adopts a ligament-friendly bionic curve, so that the base 1 is smoothly connected to the natural bone surface of the human body, providing a more friendly environment for soft tissue.

[0061] As a further optimization solution, in this embodiment, the surface of the base 1 that contacts the tibia 5 is provided with a bone-inducing growth factor coating, an antibacterial coating and a blood vessel growth factor coating.

[0062] In this embodiment, the BMP-2 component contained in the bone induction growth factor coating can stimulate the activity of osteoblasts and accelerate the bone conduction process. The silver nanoparticle antibacterial substance in the antibacterial coating can inhibit the attachment and aggregation of bacteria on the implant surface and reduce the risk of infection. The angiogenic growth factor coating can promote the formation of new blood vessels and provide sufficient nutrition for bone tissue regeneration.

[0063] The metaphyseal patch for repairing tibial bone defects disclosed in the present invention has the advantages of elastic modulus distribution that is more consistent with normal bone tissue, firm support for prosthesis, stable near- and long-term fixation, stress relief shielding, smooth transition with the natural bone surface of the human body, and ligament-friendly. The patch can be designed into various types and specifications, and the bidirectional gradient porosity is also applicable to symmetrical, asymmetrical and stepped patches, patches with or without a support body, and patches for repairing inclusive and non-inclusive metaphyseal bone defects.

[0064] The matrix disclosed in the present invention adopts a porous structure with a bidirectional gradient porosity change, and the porosity changes gradually along the proximal-distal direction of the tibia, and the porosity changes in the range of 30% to 85%. It changes gradually along the cortical bone-marrow cavity direction, and the porosity range is 30% to 85%. The matrix close to the cortical bone plays a major supporting role, is connected and fixed with the prosthesis close to the proximal side of the tibia, and is connected with the bone bed close to the distal side of the tibia. The bone density decreases along the cortical bone to the medullary cavity, and the bidirectional gradient distribution of porosity can achieve elastic modulus self-adaptation, effectively avoiding stress shielding.

[0065] The metaphyseal patch for repairing tibial bone defects includes the following steps:

[0066] S1. Collect imaging data of the patient's lower limbs to determine the size and shape of the tibial metaphysis bone defect;

[0067] S2. Select a metaphyseal patch of appropriate type, structure and specification according to the size, shape and bone density distribution of the tibial metaphyseal bone defect 1;

[0068] S3, during surgical installation, the base 1 is press-fitted and fixed to the bone bed of the tibia 5;

[0069] S4. The matrix 1 is filled with bone cement and connected to the prosthesis 3.

[0070] The above disclosure is only a preferred specific embodiment of the present invention, but the embodiments of the present invention are not limited thereto, and any changes that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A metaphysis patch for repairing tibial bone defects, configured to be connected to the metaphysis of a tibia (5) and used to support and fix a prosthesis (3) on the metaphysis, characterized in that: include: A base (1) is provided with a countersunk hole on the epiphysis along the length direction of the tibia (5), the base (1) is inserted into the countersunk hole and abuts against the inner wall thereof, the base (1) is flush with the end surface of the epiphysis, the prosthesis (3) is fixedly connected to the base (1), the base (1) is a porous structure, the porosity of the base (1) along the length direction of the tibia (5) increases gradually from the proximal end to the distal end of the tibia (5), and the porosity of the base (1) along the radial direction of the tibia (5) increases gradually from the bone cortex to the bone marrow cavity.

2. The metaphyseal patch for repairing tibial bone defects according to claim 1, characterized in that: The porosity of the matrix (1) ranges from 30% to 85%.

3. The metaphyseal patch for repairing tibial bone defects according to claim 1, characterized in that: The porous structure of the matrix (1) is a cancellous bone trabecular structure, and the pore size range of the porous structure is 0.4 to 0.6 mm. 。 4. The metaphyseal patch for repairing tibial bone defects according to claim 1, characterized in that: The cancellous bone trabecular structure adopts a periodic arrangement of cubic unit cells to construct a porous structure.

5. The metaphyseal patch for repairing tibial bone defects according to claim 1, characterized in that: The material of the substrate (1) is tantalum metal.

6. The metaphysis patch for repairing tibial bone defects according to claim 1, characterized in that: The cross section of the base (1) is an elliptical ring, and the area of ​​the cross section gradually decreases from one end close to the prosthesis (3) to the other end.

7. The metaphysis patch for repairing tibial bone defects according to claim 6, characterized in that: Also includes: A support body, the support body is embedded in a base body (1) and fixedly connected thereto, the prosthesis (3) abuts against the support body, an extension rod (4) is fixedly provided on a side of the prosthesis (3) close to the base body (1) and is parallel to the length direction of the tibia (5), and the extension rod (4) passes through the support body and is fixedly connected to the tibia (5).

8. The metaphysis patch for repairing tibial bone defects according to claim 1, characterized in that: The longitudinal cross-section of the base (1) includes: a stepped type and a symmetrical type.

9. The metaphysis patch for repairing tibial bone defects according to claim 1, characterized in that: When the patch is used to fill a non-inclusive metaphyseal bone defect, the outer contour of the matrix (1) smoothly connects with the natural bone surface of the human body.

10. The metaphysis patch for repairing tibial bone defects according to claim 1, characterized in that: The surface of the base (1) in contact with the tibia (5) is provided with a bone induction growth factor coating, an antibacterial coating and a blood vessel growth factor coating.

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