Adjustable fatigue loading device for tibial plateau pad of knee joint

Abstract

The invention provides an adjustable knee joint tibial plateau pad fatigue loading device, and belongs to the technical field of knee joint prosthesis tibial plateau pad stand column fatigue damage tests. A tibial plateau pad clamping device; the tibia plateau pad clamp tool comprises a tibia plateau pad, a screw and a rectangular pressing plate, the tibia plateau pad is located at one side end of the tibia plateau pad clamping device, the device performs an experiment by adopting a real prosthesis, and a traditional oval pressing head tool is completely replaced; and the stress state of the knee joint prosthesis in actual use can be highly restored. An oval groove matched with a real femoral condyle is formed in an adjustable rectangular block in the femoral condyle clamp tool, and the effect that the force application angle and the contact area are consistent with those of clinical working conditions is ensured by being matched with a curing liquid fixing technology; meanwhile, the 3D printing customized tibial plateau pad clamping device perfectly reproduces a contact interface between the prosthesis and the bone.

Description

Technical Field

[0001] This invention belongs to the technical field of fatigue injury testing of tibial plateau pads for knee joint prostheses, and specifically relates to an adjustable fatigue loading device for tibial plateau pads of knee joints. Background Technology

[0002] Currently, experiments on the fatigue performance of the tibial plateau pad column mainly use a fatigue testing machine with an indenter to simulate the force applied to it by the transverse ligament of the femoral condyle.

[0003] Although the current method uses simple tooling, the indenter used differs significantly from the structure of the transverse femoral condyle, making it difficult to accurately reproduce the force exerted by the transverse femoral condyle on the tibial plateau pad column under actual working conditions, which can easily lead to experimental errors. Summary of the Invention

[0004] The purpose of this invention is to provide an adjustable tibial plateau pad fatigue loading device for the knee joint, which aims to solve the problem that the existing technology uses a pressure head with a large structural difference from the femoral condyle, making it difficult to accurately reproduce the force applied by the femoral condyle to the tibial plateau pad column under actual working conditions, and easily leading to experimental errors.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] An adjustable knee joint tibial plateau pad fatigue loading device, comprising:

[0007] Tibial plateau pad clamping device;

[0008] A tibial plateau pad clamping fixture includes a tibial plateau pad, screws, and a rectangular pressure plate. The tibial plateau pad is located at one end of a tibial plateau pad clamping device, and the rectangular pressure plate is located at one end of a tibial plateau pad. The screws are threadedly connected to the tibial plateau pad clamping device, the tibial plateau pad, and the rectangular pressure plate.

[0009] A femoral condyle clamping fixture includes a U-shaped clamp, connecting screws, a fixing block, locking screw A, a pressure plate, locking screw B, and an adjustable rectangular block. The U-shaped clamp is located at one end of the tibial plateau pad clamping device, the pressure plate is located at the lower end of the U-shaped clamp, the locking screw B is threadedly connected to the U-shaped clamp and the pressure plate, the fixing block is rotatably connected to the U-shaped clamp and the pressure plate via support rods on both sides, the locking screw A is threadedly connected to the fixing block, the adjustable rectangular block is located inside the fixing block, and the connecting screw is threadedly connected to the upper end of the U-shaped clamp.

[0010] An elliptical groove is formed at the upper end of the adjustable rectangular block;

[0011] The femoral condyle is installed in an elliptical groove, and its adjustment range is 31mm-53mm.

[0012] As a preferred embodiment of the present invention, the clamping device has a T-shaped structure, with a bottom plate for fixed connection to the experimental machine workbench, and a groove provided on the inner side of the vertical plate.

[0013] As a preferred embodiment of the present invention, the connecting screw has an M16 to M12 thread structure, which can be replaced according to the size of the testing machine.

[0014] As a preferred embodiment of the present invention, the length adjustment range of the adjustable rectangular block is 0-50mm.

[0015] As a preferred embodiment of the present invention, the tibial plateau pad clamping device is made of polyethylene material by 3D printing, and the groove size is customized according to the actual size of the tibial plateau pad.

[0016] In a preferred embodiment of the present invention, the femoral condyle is fixed in the elliptical groove of the adjustable rectangular block by a curing liquid.

[0017] In a preferred embodiment of the present invention, the U-shaped clamp is used in conjunction with the pressure plate.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] 1. This device, using a real prosthesis for testing, completely replaces the traditional elliptical indenter fixture, highly replicating the stress state of the knee joint prosthesis in actual use. Specifically, the adjustable rectangular block in the femoral condyle clamp fixture has an elliptical groove matching the real femoral condyle, and with the curing fluid fixation technology, ensures that the force application angle and contact area are consistent with clinical conditions. Simultaneously, the 3D-printed customized tibial plateau pad clamping device perfectly replicates the contact interface between the prosthesis and the bone. This highly realistic design allows experimental data to accurately reflect the fatigue performance of the prosthesis in the human body, significantly improving the accuracy of test results and their clinical reference value.

[0020] 2. On the one hand, the split-type femoral condyle clamp fixture and tibial plateau pad clamp fixture can be adjusted independently or work together. The clever combination of the U-shaped clamp and the pressure block enables rapid assembly and disassembly of the fixation block. On the other hand, the adjustable rectangular block provides a length adjustment range of 0-50mm and a groove adjustment range of 31-53mm. Combined with interchangeable M16 to M12 connecting screws, a single device can be adapted to different specifications of prostheses and various testing machines. This design not only solves the problem of cumbersome fixture changes in traditional testing but also reduces the investment cost of experimental equipment in the fatigue damage test of the tibial plateau pad column of the knee joint prosthesis.

[0021] 3. The tibial plateau pad clamping device, which is 3D printed with polyethylene, combines structural precision with moderate elasticity. It can ensure the stable clamping of the prosthesis and avoid abnormal damage caused by stress concentration. The curing fluid fixation method of the femoral condyle effectively eliminates the micro-motion wear caused by traditional mechanical clamping. Attached Figure Description

[0022] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0023] Figure 1 This is a front perspective view of the present invention;

[0024] Figure 2 This is a disassembled diagram of the femoral clamp in this invention;

[0025] Figure 3 This is a diagram of the tibial plateau pad clamping fixture in this invention.

[0026] In the figure: 1. Tibial plateau pad clamping device; 2. Tibial plateau pad; 3. Screw; 4. Rectangular pressure plate; 5. U-shaped clamp; 6. Connecting screw; 7. Fixing block; 8. Locking screw A; 9. Pressure plate; 10. Femoral condyle; 11. Locking screw B; 12. Adjustable rectangular block. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Example 1

[0029] Please see Figures 1-3 The present invention provides the following technical solutions:

[0030] An adjustable knee joint tibial plateau pad fatigue loading device, comprising:

[0031] Tibial plateau pad clamping device 1;

[0032] The tibial plateau pad clamping fixture includes a tibial plateau pad 2, a screw 3 and a rectangular pressure plate 4. The tibial plateau pad 2 is located at one side of the tibial plateau pad clamping device 1, the rectangular pressure plate 4 is located at one side of the tibial plateau pad 2, and the screw 3 is threadedly connected to the tibial plateau pad clamping device 1, the tibial plateau pad 2 and the rectangular pressure plate 4.

[0033] The femoral condyle clamp fixture includes a U-shaped clamp 5, a connecting screw 6, a fixing block 7, a locking screw A8, a pressure plate 9, a locking screw B11, and an adjustable rectangular block 12. The U-shaped clamp 5 is located at one end of the tibial plateau pad clamping device 1, the pressure plate 9 is located at the lower end of the U-shaped clamp 5, the locking screw B11 is threaded into the U-shaped clamp 5 and the pressure plate 9, the fixing block 7 is rotatably connected to the U-shaped clamp 5 and the pressure plate 9 through the support rods on both sides, the locking screw A8 is threaded into the fixing block 7, the adjustable rectangular block 12 is located in the fixing block 7, and the connecting screw 6 is threaded into the upper end of the U-shaped clamp 5.

[0034] An elliptical groove is provided at the upper end of the adjustable rectangular block 12;

[0035] The femoral condyle 10 is installed in an oval groove, and its adjustment range is 31mm-53mm.

[0036] In a specific embodiment of the present invention, when conducting a fatigue loading test on the tibial plateau pad of the knee joint, the tibial plateau pad 2 is first placed in the groove of the tibial plateau pad clamping device 1, then pressed with a rectangular pressure plate 4 and fixed with screws 3; this ensures that the tibial plateau pad 2 remains stable during the test. When installing the femoral condyle clamping fixture, the U-shaped clamp 5 is first connected to the testing machine through connecting screws 6, then the pressure plate 9 is installed at the lower end of the U-shaped clamp 5 and fixed with locking screws B11; then the fixing block 7 is connected to the U-shaped clamp 5 and pressure plate 9 through the two side support rods, and the position of the adjustable rectangular block 12 is adjusted by locking screws A8; this can accommodate femoral condyles 10 of different sizes. When installing the femoral condyle 10, it is placed in the elliptical groove of the adjustable rectangular block 12 and fixed with curing liquid; this ensures that the femoral condyle 10 remains stable during the test. To ensure the femoral condyle 10 does not shift during loading, the femoral condyle 10 applies a periodic load to the tibial plateau pad 2 during machine operation, simulating actual knee joint movement. This accurately reproduces the actual stress state of the product, improving the accuracy of experimental data. A split-type fixture design is adopted, with the femoral condyle clamping fixture and the tibial plateau pad clamping fixture installed independently for easy adjustment and maintenance. The adjustable rectangular block 12 and connecting screw 6 can adapt to different sizes of femoral condyles 10 and testing machines, improving the device's versatility. The tibial plateau pad clamping device 1 is custom-made using 3D printing to ensure a tight fit with the tibial plateau pad 2, reducing experimental errors. The femoral condyle 10 is fixed with a curing liquid to prevent displacement during loading, improving experimental stability. The overall structure is simple, reliable, and easy to operate, suitable for fatigue performance testing of various knee joint prostheses.

[0037] Please refer to the details. Figures 1-3 The clamping device 1 has a T-shaped structure, with a bottom plate for fixed connection to the experimental machine workbench, and a groove on the inner side of the vertical plate.

[0038] In this embodiment: the T-shaped structure design provides a stable support base for the clamping device 1, and the bottom plate is firmly connected to the experimental machine workbench by bolts or other fixing methods to ensure that no displacement occurs during the experiment; the groove shape on the inner side of the vertical plate matches the outer contour of the tibial platform pad 2, so that the specimen can be accurately positioned and maintain a stable clamping state, thereby improving the reliability of the experimental data.

[0039] Please refer to the details. Figures 1-3 The connecting screw 6 has an M16 to M12 thread structure, which can be replaced according to the size of the testing machine.

[0040] In this embodiment, the connecting screw 6 adopts a variable diameter thread design of M16 to M12. One end of it is M16 and connects to the U-shaped clamp 5, while the other end is M12 and matches the interface of different models of testing machines. This modular design enables the device to be quickly adapted to various testing machine equipment. Only the corresponding specification of the connecting screw 6 needs to be replaced to complete the equipment docking, which significantly improves the versatility of the device and the experimental efficiency.

[0041] Please refer to the details. Figures 1-3 The length of the adjustable rectangular block 12 can be adjusted from 0 to 50 mm.

[0042] In this embodiment, the adjustable rectangular block 12 slides with the fixed block 7 through a groove, and its adjustment range covers 0-50mm, which can adapt to the installation requirements of different sizes of femoral condyles 10. After adjustment, it is fixed by locking screw A8 to ensure that no displacement occurs during loading. This design allows the same set of devices to meet the testing requirements of multiple sizes of prostheses, reducing experimental costs.

[0043] Please refer to the details. Figures 1-3 The tibial plateau pad clamping device 1 is made of polyethylene material by 3D printing, and its groove size is customized according to the actual size of the tibial plateau pad 2.

[0044] In this embodiment, the polyethylene clamping device 1 manufactured using 3D printing technology has the advantages of being lightweight, highly precise, and customizable. Its inner groove can be customized according to the specific tibial plateau pad 2 size parameters to achieve a perfect fit with the specimen. The elastic properties of polyethylene material can ensure clamping force while avoiding damage to the specimen surface, making it particularly suitable for fatigue testing of precision medical devices.

[0045] Please refer to the details. Figures 1-3 The femoral condyle 10 is fixed in the elliptical groove of the adjustable rectangular block 12 by a curing liquid.

[0046] In this embodiment: a special curing liquid is injected into the elliptical groove, and after the femoral condyle 10 is positioned, it is cured to form a stable connection; this fixation method can not only eliminate the assembly gap, but also completely reproduce the actual contact state between the femoral condyle 10 and the tibial plateau pad 2. Compared with mechanical clamping, it is closer to the physiological stress environment, making the fatigue test results more clinically valuable.

[0047] Please refer to the details. Figures 1-3 The U-shaped clamp 5 is used in conjunction with the pressure plate 9.

[0048] In this embodiment: the open end of the U-shaped clamp 5 and the pressure plate 9 form an openable clamping space, and the tightness is controlled by the locking screw B11; this design allows the fixing block 7 to be quickly disassembled and assembled, which is convenient for adjusting the position of the adjustable rectangular block 12 and for replacing different models of femoral condyle 10 components. The fatigue damage test of the tibial plateau pad column of the knee joint prosthesis improves the experimental preparation efficiency, while ensuring that the overall rigidity of the loading system meets the requirements of high frequency fatigue testing.

[0049] The working principle and usage process of this invention are as follows: The bottom plate of the T-shaped tibial plateau pad clamping device 1 is fixed to the testing machine's worktable. The tibial plateau pad 2 is placed into the customized groove of the clamping device 1. A rectangular pressure plate 4 is placed on the tibial plateau pad 2 and locked in place with screws 3. The U-shaped clamp 5 is connected to the testing machine via connecting screws 6M16 to M12. A pressure plate 9 is installed at the bottom of the U-shaped clamp 5 and fixed with locking screws B11. A fixing block 7 is inserted between the U-shaped clamp 5 and the pressure plate 9. After adjusting the position, it is locked. The adjustable rectangular block 12 is slid to the desired position and fixed with locking screws A8. The femoral condyle 10 is placed into the elliptical groove of the adjustable rectangular block 12, and a curing liquid is injected to fix it. The entire testing machine precisely aligns the contact surfaces of the femoral condyle 10 and the tibial plateau pad 2 to simulate the stress state of a real knee joint. The testing machine applies periodic loads to the femoral condyle 10 according to set parameters to simulate knee joint movement. It monitors the stress distribution, deformation, and fatigue damage of the tibial plateau pad 2 in real time. Experimental data is collected through sensors to analyze the fatigue performance of the tibial plateau pad 2 and evaluate its service life and reliability. The fixation method of the femoral condyle 10 and the tibial plateau pad 2 simulates real knee joint movement, improving experimental accuracy. The 3D-printed custom fixtures, adjustable mechanisms, and quick-connect design shorten the experimental preparation time. Stable clamping and precise loading control ensure that the fatigue test data are true and valid.

[0050] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An adjustable knee joint tibial plateau pad fatigue loading device, characterized in that: include: Tibial plateau pad clamping device (1); Tibial plateau pad clamping fixture, the tibial plateau pad clamping fixture includes a tibial plateau pad (2), a screw (3) and a rectangular pressure plate (4), the tibial plateau pad (2) is located at one side of the tibial plateau pad clamping device (1), the rectangular pressure plate (4) is located at one side of the tibial plateau pad (2), and the screw (3) is threadedly connected to the tibial plateau pad clamping device (1), the tibial plateau pad (2) and the rectangular pressure plate (4); The femoral condyle clamp fixture includes a U-shaped clamp (5), a connecting screw (6), a fixing block (7), a locking screw A (8), a pressure plate (9), a locking screw B (11), and an adjustable rectangular block (12). The U-shaped clamp (5) is located at one side of the tibial plateau pad clamping device (1). The pressure plate (9) is located at the lower end of the U-shaped clamp (5). The locking screw B (11) is threaded into the U-shaped clamp (5) and the pressure plate (9). The fixing block (7) is rotatably connected to the U-shaped clamp (5) and the pressure plate (9) through the support rods on both sides. The locking screw A (8) is threaded into the fixing block (7). The adjustable rectangular block (12) is located in the fixing block (7). The connecting screw (6) is threaded into the upper end of the U-shaped clamp (5). An elliptical groove is provided at the upper end of the adjustable rectangular block (12); Femoral condyle (10), which is installed in an elliptical groove and has an adjustment range of 31mm-53mm.

2. The adjustable knee joint tibial plateau pad fatigue loading device according to claim 1, characterized in that: The clamping device (1) has a T-shaped structure, with a bottom plate for fixed connection to the experimental machine workbench and a groove on the inner side of the vertical plate.

3. The adjustable knee joint tibial plateau pad fatigue loading device according to claim 2, characterized in that: The connecting screw (6) has an M16 to M12 thread structure and can be replaced according to the size of the testing machine.

4. The adjustable knee joint tibial plateau pad fatigue loading device according to claim 3, characterized in that: The length of the adjustable rectangular block (12) can be adjusted from 0 to 50 mm.

5. The adjustable knee joint tibial plateau pad fatigue loading device according to claim 4, characterized in that: The tibial plateau pad clamping device (1) is made of polyethylene material by 3D printing, and its groove size is customized according to the actual size of the tibial plateau pad (2).

6. The adjustable knee joint tibial plateau pad fatigue loading device according to claim 5, characterized in that: The femoral condyle (10) is fixed in the elliptical groove of the adjustable rectangular block (12) by a curing liquid.

7. The adjustable knee joint tibial plateau pad fatigue loading device according to claim 6, characterized in that: The U-shaped clamp (5) is used in conjunction with the pressure plate (9).

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