Spacer for repairing bone defects in total knee revision surgery

Abstract

The present invention relates to a pad for repairing bone defects in total knee revision surgery, belonging to the technical field of orthopedic medical devices, and comprising a main body, wherein the main body is a porous structure, and the porosity of the main body along the length direction of the tibia increases gradually from the tibial tray to the bone bed, and the porosity of the main body along the radial direction of the tibia increases gradually from the cortical bone to the medullary cavity. The present invention arranges the main body in the bone defect area between the tibial tray and the tibial bone bed, so that the main body fills the bone defect and supports the tibial tray, and then utilizes the porosity of the main body to increase gradually from the tibial tray to the bone bed and from the cortical bone to the medullary cavity, so that the porosity of the pad changes in a bidirectional gradient, and the bidirectional gradient porosity realizes a porous structure with adaptive elastic modulus, so that the elastic modulus of different areas where the pad contacts the bone bed are matched, which satisfies the support for the prosthesis while effectively alleviating the stress shielding effect.

Description

Technical Field

[0001] The invention belongs to the technical field of orthopedic medical devices, and in particular relates to a pad for repairing bone defects in total knee arthroplasty. Background Art

[0002] In total knee revision surgery, there are often bone defects of varying degrees between the prosthesis and the bone bed. Different reconstruction schemes can be used for bone defects according to the pathological and physiological conditions of the bone defect (such as mechanical wear, bone dissolution caused by infection, etc.) and the degree of the bone defect. For those with a milder degree of defect, bone cement filling, bone cement combined with screws, bone grafting and other methods can be used. For those with a larger degree of defect, pads, conical patches, sleeves and the like are needed to fill the bone defect. Among them, when the degree of bone defect on the medial side of the tibia is large, metal pads are mostly used to fill the defect between the tibial tray and the tibial bone bed. The material of the metal pad is mostly titanium alloy or cobalt-chromium alloy, and the homogeneous metal pad can provide support for the prosthesis. However, the elastic modulus of the existing metal pad and the bone tissue at the implantation site is quite different, and stress shielding phenomenon will occur, leading to various complications such as bone absorption and collapse around the prosthesis, loosening and displacement of the prosthesis.

[0003] At present, in order to reduce the difference in elastic modulus between the pad and the bone tissue at the implantation site, the prior art mostly uses a pad with uniform porosity for filling, which can reduce the difference in elastic modulus and alleviate stress shielding. However, studies have found that the elastic modulus of normal tibia gradually decreases from the cortical bone to the medullary cavity, and gradually decreases from the proximal end of the tibia to the distal end. The elastic modulus of different areas where the pad with uniform porosity contacts the bone bed still differ, resulting in limited effect on stress shielding alleviation. Summary of the invention

[0004] In view of this, the present invention provides a pad for repairing bone defects in total knee revision surgery to address the deficiencies in the prior art. The present invention can achieve matching of the elastic moduli of different areas where the pad contacts the bone bed, thereby meeting the support for the prosthesis and effectively alleviating the stress shielding effect.

[0005] The technical solution of the present invention is: a pad for repairing bone defects in total knee revision surgery, including a main body, which is a porous structure, and the porosity of the main body along the length direction of the tibia increases gradually from the tibial tray to the bone bed, and the porosity of the main body along the radial direction of the tibia increases gradually from the cortical bone to the medullary cavity.

[0006] Preferably, the porosity of the main body is in the range of 30% to 85%.

[0007] Preferably, the longitudinal section of the main body is rectangular or wedge-shaped. When the longitudinal section of the main body is wedge-shaped, the angle range of the wedge is 16° to 26°, and the thickness of the main body gradually decreases from the cortical bone to the medullary cavity.

[0008] Preferably, the main body is a cancellous bone trabecular structure imitating a cancellous bone trabecular structure, and the cancellous bone trabecular structure is constructed into a porous structure by periodically arranging cubic unit cells.

[0009] Preferably, the material of the main body is titanium alloy or tantalum metal. When the material of the main body is titanium alloy, the pore size range is 0.1 mm to 0.4 mm. When the material of the main body is tantalum metal, the pore size range is 0.4 mm to 0.6 mm.

[0010] Preferably, an extension rod is fixedly provided on one side of the tibial tray close to the tibial bone bed and is perpendicular to the tibial tray. The extension rod is inserted into the tibial bone bed and fixedly connected thereto. An arc-shaped groove is provided on one side of the main body close to the extension rod, and the arc-shaped groove abuts against the extension rod.

[0011] Preferably, a plurality of wing plates are fixedly provided on the outer side of the extension rod and are respectively parallel to the center line of the extension rod. The main body is provided with a rectangular groove on the arc-shaped groove, and the wing plates are embedded in the groove and are cooperatively connected therewith.

[0012] Preferably, two through holes are provided on the main body, the center lines of the through holes are parallel to the center line of the extension rod, the two through holes are respectively located on both sides of the rectangular groove, and threads are provided on the inner walls of the through holes so that the threaded fasteners can be matched and connected with the threads in the through holes, and the threaded fasteners pass through the through holes and are fixedly connected with the threads of the tibial tray.

[0013] Preferably, it also includes a support body, which is a solid structure. The support body is fixed around the outer side of the main body along the contour of the main body. The support body is fixed around the inner wall of each through hole and is flush with both sides of the main body. The thread is arranged on the inner side of the support body in the through hole.

[0014] Preferably, the surface of the main body in contact with the tibial bone bed 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 pad for repairing bone defects in total knee revision surgery. By arranging the main body in the bone defect area between the tibial tray and the tibial bone bed, the main body fills the bone defect, thereby supporting the tibial tray. The porosity of the main body increases gradually from the tibial tray to the bone bed and from the cortical bone to the medullary cavity, so that the porosity of the pad changes in a bidirectional gradient. The bidirectional gradient porosity realizes a porous structure with adaptive elastic modulus, which makes the elastic modulus of different areas of the pad in contact with the bone bed fit together, thereby meeting the support for the prosthesis and effectively alleviating the stress shielding effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the installation of the first embodiment of the bone defect repair pad of the present invention;

[0017] Figure 2 This is a schematic diagram of the installation of a second embodiment of a bone defect repairing pad of the present invention;

[0018] Figure 3 This is a front view of the bone defect repair pad of the present invention;

[0019] Figure 4 is a side view of the bone defect repair pad of the present invention;

[0020] Figure 5 It is a stereoscopic diagram of a first embodiment of a bone defect repairing pad of the present invention;

[0021] Figure 6 It is a stereoscopic diagram of a second embodiment of a bone defect repairing pad of the present invention. DETAILED DESCRIPTION

[0022] The present invention provides a pad for repairing bone defects in total knee arthroplasty. Figures 1 to 6 The present invention is described with reference to the structural schematic diagram of FIG.

[0023] 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.

[0024] Total knee revision surgery is a surgery that is performed after knee replacement surgery when the knee joint has symptoms such as looseness, infection, pain, and limited flexion and extension function. The knee joint needs to be re-repaired. That is, the prosthesis implanted in the knee replacement surgery is removed and a new prosthesis is reinstalled. The prosthesis is provided with an extension rod, which is inserted into the medullary cavity to fix the prosthesis to restore normal knee joint function. In total knee revision surgery, there are often bone defects of varying degrees between the prosthesis and the bone bed. The main causes of bone defects are: mechanical bone loss caused by prosthesis loosening, osteolysis caused by chronic infection, and improper medical operation. According to the pathological and physiological conditions of the bone defect (such as mechanical wear, osteolysis caused by infection, etc.) and the degree of bone defect, different reconstruction plans can be used for bone defects. For those with a milder degree of defect, bone cement filling, bone cement combined with screws, bone grafting, etc. can be used. For those with a larger degree of defect, pads, conical patches, sleeves, etc. are needed to fill the bone defect. When the degree of bone defect on the inner side of the tibia is large, metal pads are mostly used to fill the defect between the tibial tray and the tibial bone bed. The metal pads are mostly made of titanium alloy or cobalt-chromium alloy, and the homogeneous metal pads can provide support for the prosthesis. However, the elastic modulus of the existing metal pads and the bone tissue at the implant site is quite different, which will cause stress shielding, leading to various complications such as bone absorption and collapse around the prosthesis, loosening and displacement of the prosthesis.

[0025] At present, in order to reduce the difference in elastic modulus between the pad and the bone tissue at the implantation site, the prior art mostly uses a pad with uniform porosity for filling, which can reduce the difference in elastic modulus and alleviate stress shielding. However, studies have found that the elastic modulus of normal tibia gradually decreases from the cortical bone to the medullary cavity, and gradually decreases from the proximal end of the tibia to the distal end. The elastic modulus of different areas where the pad with uniform porosity contacts the bone bed still differ, resulting in limited effect on stress shielding alleviation.

[0026] Based on the above problems, an embodiment of the present invention provides a pad for repairing bone defects in total knee revision surgery. The main body is arranged in the bone defect area between the tibial tray and the tibial bone bed, so that the main body fills the bone defect, thereby supporting the tibial tray. The porosity of the main body of the porous structure changes in a bidirectional gradient. The porosity of the main body near the tibial tray is relatively small to ensure the strength of the connection with the tibial tray. The porosity of the main body near the bone bed is relatively large to promote bone integration. The porosity of the part of the cortical bone area filled by the main body is relatively small, which can further support the tibial tray. The porosity of the main body near the medullary cavity is relatively large to promote the growth of surrounding bones. The bidirectional gradient porosity realizes a porous structure with adaptive elastic modulus, which realizes the matching of the elastic modulus of different areas in contact with the bone bed. While meeting the support for the prosthesis, it effectively reduces the stress shielding effect and can also promote bone growth.

[0027] A spacer for repairing bone defects in total knee arthroplasty. Figure 1 The installation diagram of the first embodiment of the bone defect repair pad is a rectangular pad installation diagram, including a main body 11, the longitudinal section of the main body 11 is rectangular, the tibial tray 3 is fixed on the bone bed of the tibia 4 and abuts against it, the main body 11 is arranged in the bone defect area between the tibial tray 3 and the bone bed of the tibia 4, the main body 11 abuts against the bone beds of the tibial tray 3 and the tibia 4 respectively, the main body 11 is fixedly connected to the tibial tray 3, and is used to support the tibial tray 3 to restore the normal function of the knee joint. The main body 11 is a porous structure, such as Figure 4 FIG. 1 is a side view of the bone defect repair pad of this embodiment. The porosity of the main body 11 along the length direction of the tibia increases gradually from the tibial tray 3 to the bone bed direction. Figure 3 The figure shows a front view of the bone defect repair pad of the present embodiment, wherein the porosity of the main body 11 along the radial direction of the tibia increases gradually from the cortical bone to the medullary cavity (direction 15 to 14).

[0028] The pad block for repairing bone defects in total knee revision surgery disclosed in this embodiment has a main body 11 disposed in the bone defect area between the tibial tray 3 and the tibial bone bed 4, so that the main body 11 supports the tibial tray 3. At the same time, the porosity of the main body 11 increases gradually from the tibial tray 3 to the bone bed (16 to 17 direction) and from the cortical bone to the medullary cavity (15 to 14 direction), so that the porosity of the main body 11 changes in a bidirectional gradient, thereby reducing the difference in elastic modulus between different areas where the pad block contacts the bone bed, and effectively mitigating the stress shielding effect as much as possible.

[0029] In this embodiment, the porosity of the main body 11 changes in a bidirectional gradient. The porous structure with adaptive elastic modulus can be designed according to the bone density distribution law of the filling part of the lower limb of the human body. During the operation, the pad is selected according to the patient's bone density and bone defect condition to make the elastic modulus of the pad close to that of normal bone tissue, thereby realizing a porous structure with adaptive elastic modulus to improve the mechanical properties and effectively reduce the stress shielding effect.

[0030] After the main body 11 in this embodiment is fixed to the tibial tray 3, the extension rod on the tibial tray 3 is pressed into the bone bed by means of press-fitting. After the side of the main body 11 away from the tibial tray 3 abuts against the bone bed, the tibial tray 3 and the main body 11 are fixed.

[0031] As a further optimization solution, the porosity of the main body 11 in this embodiment ranges from 30% to 85%.

[0032] The porosity range of the main body 11 disclosed in the present embodiment is 30% to 85%, and the porosity of the porous structure of the main body has a bidirectional gradient change, which changes gradually along the tibial prosthesis-bone bed direction. The porosity of the main body 11 near the tibial tray is relatively small to ensure the strength of the connection with the tibial tray, and the porosity near the bone bed is relatively large to promote bone integration; it changes gradually along the bone cortex-marrow cavity direction, and the porosity of the area filled with cortical bone is relatively small to play a supporting role, and the porosity of the area near the medullary cavity is relatively large to promote the growth of surrounding bones.

[0033] The porosity adjustment range of the porous structure of the main body 11 disclosed in this embodiment is 30% to 85%, and the elastic modulus variation range is 0.337GPa to 6GPa, which is between cancellous bone (0.1GPa to 0.5GPa) and cortical bone (12GPa to 18GPa), further making the elastic modulus of the pad close to that of normal bone tissue, thereby alleviating the stress shielding effect.

[0034] As shown in the figure, Figure 5 This is a stereoscopic diagram of a first embodiment of a bone defect repair pad. Figure 6 A stereoscopic diagram of the second embodiment of the bone defect repair pad. As a further optimization scheme, the longitudinal section of the main body 11 in this embodiment is rectangular or wedge-shaped. When the longitudinal section of the main body 11 is wedge-shaped, the angle range of the wedge is 16° to 26°, and the thickness of the main body 11 gradually decreases from the cortical bone to the medullary cavity.

[0035] In this embodiment, the longitudinal section of the main body 11 includes a rectangular shape and a wedge shape. The bidirectional gradient porosity characteristics of the pad are suitable for different categories and models such as rectangular pads and wedge-shaped pads. The appropriate category and model of the product can be selected according to the bone defect of the filling part to minimize the amount of surgical osteotomy and retain the patient's own bone. Figure 2 This is a schematic diagram of the installation of a second embodiment of a bone defect repair pad. The longitudinal section of the main body 11 is wedge-shaped, which further improves the ease of use of the pad.

[0036] In this embodiment, the thickness of the main body 11 ranges from 5 mm to 15 mm. At the same time, the cross-sectional profile of the main body 11 matches the shape of the tibial tray prosthesis. The edge contour of the main body 11 is flush with or slightly smaller than the edge contour of the tibial tray 3, and the edge transition is smooth to avoid soft tissue damage.

[0037] As a further optimization solution, the main body 11 in this embodiment is a cancellous bone trabecular structure, and the cancellous bone trabecular structure is constructed into a porous structure by periodically arranging cubic unit cells.

[0038] The main body 11 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.

[0039] As a further optimization solution, in this embodiment, the material of the main body 11 is titanium alloy or tantalum metal. When the material of the main body 11 is titanium alloy, the aperture range is 0.1mm~0.4mm, and when the material is tantalum metal, the aperture range is 0.4mm~0.6mm.

[0040] The main body 11 in this embodiment is made of titanium alloy or tantalum metal. The porous tantalum has good biocompatibility and the porous structure imitates the trabecular structure. The pore size range is 0.1mm to 0.4mm for titanium alloy and 0.4mm to 0.6mm for tantalum metal. The pore size is within the reasonable range for bone tissue growth.

[0041] As a further optimization scheme, in this embodiment, an extension rod is fixedly provided on the side of the tibial tray 3 close to the tibial 4 bone bed, and is perpendicular to the tibial tray 3. The extension rod is inserted into the tibial 4 bone bed and fixedly connected thereto, and an arc-shaped groove is provided on the side of the main body 11 close to the extension rod, and the arc-shaped groove abuts against the extension rod.

[0042] In this embodiment, an extension rod is used to fix the tibial tray 3 on the tibial 4 bone bed. At the same time, the arc groove on the main body 11 abuts against the extension rod, further improving the stability of the pad block, so that the pad block can stably support the tibial tray 3.

[0043] As a further optimization solution, in this embodiment, a plurality of wing plates are fixedly provided on the outer side of the extension rod, and are respectively parallel to the center line of the extension rod. The main body 11 is located on the arc-shaped groove and has a rectangular groove, and the wing plates are embedded in the groove and are connected therewith.

[0044] In this embodiment, the wing plate on the outside of the extension rod is embedded in the bone bed of the tibia 4, which can improve the fixation of the extension rod and the bone bed of the tibia 4. At the same time, the rectangular groove on the main body 11 is used in conjunction with one of the wing plates to further improve the stability of the fixation of the main body 11 with the extension rod and the tibial tray 3.

[0045] As a further optimization scheme, in the present embodiment, two through holes 12 are provided on the main body 11, and the center lines of the through holes 12 are parallel to the center lines of the extension rods. The two through holes 12 are respectively located on both sides of the rectangular groove, and threads are provided on the inner walls of the through holes 12 so that the threaded fasteners can be matched and connected with the threads in the through holes 12, and the threaded fasteners pass through the through holes 12 and are fixedly connected with the tibial tray 3 by threads.

[0046] The two through holes 12 in this embodiment utilize the threads set on the inner sides thereof so that the threaded fasteners pass through the through holes 12 and are fixedly connected to the main body 11 by threads. After passing through the main body 11, the threaded fasteners are threadedly matched with the tibial tray 3 and are fixedly connected. The threaded fasteners are utilized to prevent the main body 11 from rotating, thereby improving the stability of the fixation of the main body 11. The threaded structure is utilized to position and fix the main body 11, thereby ensuring that the main body 11 and the tibial tray are correctly positioned and reliably connected, thereby preventing relative rotation.

[0047] In this embodiment, the two through holes 12 are respectively located at the front and rear sides near the central axis between the inner and outer sides (14, 15) of the cushion block.

[0048] In this embodiment, the thread size inside the through hole 12 is the same as the thread size on the tibial tray.

[0049] In this embodiment, the distance between the center line of the through hole 12 and the edge of the main body 11 ranges from 8 mm to 15 mm.

[0050] In this embodiment, when the strength around the through hole 12 is insufficient, a solid structure or a porous structure with low porosity, a screw sleeve, etc. can be used around the through hole 12 to provide necessary strength support, so that the main body 11 can provide sufficient support for the tibial tray 3.

[0051] As a further optimization scheme, the present embodiment also includes a support body 13, which is a solid structure. The support body 13 is fixed around the outer side of the main body 11 along the contour of the main body 11. The support body 13 is fixed around the inner wall of each through hole 12 respectively and is flush with the two sides of the main body 11. The thread is arranged on the inner side of the support body 13 in the through hole 12.

[0052] In this embodiment, a solid support body 13 is used, which is fixed around the outer contour of the main body 11 and fixed on the inner wall of the through hole 12 in a form similar to a circular tube. It can further provide necessary support for the pad, ensure the strength of the bone defect pad, and meet the support of the main body 11 for the tibial tray 3.

[0053] In this embodiment, the thickness of the support body 13 ranges from 3 mm to 5 mm, and the thickness of the support body depends on the required support strength. The porous structure of the main body 11 and the solid structure of the support body 13 are integrally formed using 3D printing technology, and the material is titanium alloy or tantalum metal, and the thread is formed by mechanical processing.

[0054] In this embodiment, when the strength of the main body 11 is sufficient, the support body 13 may not be included.

[0055] As a further optimization solution, in this embodiment, the surface of the main body 11 that contacts the bone bed of the tibia 4 is provided with a bone induction growth factor coating, an antibacterial coating and a vascular growth factor coating.

[0056] In this embodiment, the surface of the main body 11 is treated. 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 adhesion 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.

[0057] The present invention provides a pad for repairing bone defects in total knee arthroplasty. The pad has a bidirectional gradient pore structure design that makes the elastic modulus of the pad closer to the elastic modulus range and distribution law of normal bone tissue, reduces stress shielding, and improves the mechanical environment. At the same time, tantalum metal has good biocompatibility, the trabecular structure provides a structural support for bone growth, and the pore size range is conducive to bone growth. The pad for repairing bone defects of the present invention is designed as a serialized product, and the appropriate model of the product can be selected according to the patient's bone defect and bone density, thereby reducing application costs and improving product quality.

[0058] The present invention provides a pad installation implementation process for repairing bone defects in total knee arthroplasty, which includes:

[0059] S1. Collect imaging data of the patient's lower limbs to determine the location, size and bone density of the tibial bone defect;

[0060] S2. Select an appropriate bidirectional gradient porosity body according to the location, size and bone density of the bone defect;

[0061] S3. The upper surface of the main body 11 contacts the tibial tray and is fixed to the tibial tray with screws, and the lower surface of the main body 11 is press-fitted and fixed to the bone bed.

[0062] 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 spacer for repairing bone defects in total knee arthroplasty, characterized in that: include: A main body (11), wherein the main body (11) is a porous structure, wherein the porosity of the main body (11) along the length direction of the tibia increases gradually from the tibial tray (3) to the bone bed, and the porosity of the main body (11) along the radial direction of the tibia increases gradually from the cortical bone to the medullary cavity; An extension rod is fixedly provided on one side of the tibial tray (3) close to the tibial (4) bone bed and is perpendicular to the tibial tray (3). The extension rod is inserted into the tibial (4) bone bed and is fixedly connected thereto. An arc-shaped groove is provided on one side of the main body (11) close to the extension rod, and the arc-shaped groove abuts against the extension rod. A plurality of wing plates are fixedly arranged on the outer side of the extension rod and are respectively parallel to the center line of the extension rod. The main body (11) is provided with a rectangular groove on the arc-shaped groove, and the wing plates are embedded in the groove and are matched and connected therewith.

2. The spacer for repairing bone defects in total knee arthroplasty according to claim 1, characterized in that: The porosity of the main body (11) ranges from 30% to 85%.

3. The spacer for repairing bone defects in total knee arthroplasty according to claim 1, characterized in that: The longitudinal section of the main body (11) is rectangular or wedge-shaped. When the longitudinal section of the main body (11) is wedge-shaped, the angle range of the wedge is 16° to 26°, and the thickness of the main body (11) gradually decreases from the cortical bone to the medullary cavity.

4. The spacer for repairing bone defects in total knee arthroplasty according to claim 1, characterized in that: The main body (11) is a cancellous bone trabecular structure imitating a cancellous bone trabecular structure, and the cancellous bone trabecular structure is constructed by periodically arranging cubic unit cells to form a porous structure.

5. The spacer for repairing bone defects in total knee arthroplasty according to claim 1, characterized in that: The material of the main body (11) is titanium alloy or tantalum metal. When the material of the main body (11) is titanium alloy, the aperture range is 0.1 mm to 0.4 mm. When the material of the main body (11) is tantalum metal, the aperture range is 0.4 mm to 0.6 mm.

6. The spacer for repairing bone defects in total knee arthroplasty according to claim 1, characterized in that: The main body (11) is provided with two through holes (12), the center lines of the through holes (12) are parallel to the center lines of the extension rod, the two through holes (12) are respectively located on both sides of the rectangular groove, and the inner walls of the through holes (12) are provided with threads so that the threaded fasteners can be matched and connected with the threads in the through holes (12), and the threaded fasteners pass through the through holes (12) and are fixedly connected with the threads of the tibial tray (3).

7. The spacer for repairing bone defects in total knee arthroplasty according to claim 6, characterized in that: Also includes: A support body (13), the support body (13) is a solid structure, the support body (13) is fixed around the outer side of the main body (11) along the contour thereof, the support body (13) is fixed around the inner wall of each through hole (12) and is flush with both sides of the main body (11), and the thread is arranged on the inner side of the support body (13) in the through hole (12).

8. The spacer for repairing bone defects in total knee arthroplasty according to claim 1, characterized in that: The surface of the main body (11) in contact with the tibia (4) bone bed is provided with a bone induction growth factor coating, an antibacterial coating and a blood vessel growth factor coating.

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