Method and device for testing contact pressure between joint prosthesis components

Abstract

The invention belongs to the technical field of orthopedic implants, and discloses a method and a device for testing contact pressure between joint prosthesis assemblys.The technical scheme includes that S1, joint assemblies are aligned and mounted on a testing machine, and buckling angles of the joint assemblies on a sagittal plane are adjusted; s2, applying different axial loads; s3, adjusting test loading time; s4, temperature setting influence is adjusted, a pretreatment test device and a contact pressure test device need to be provided on the basis of innovation of the method, the pretreatment device can achieve buckling angle condition, internal rotation angle and displacement distance setting and achieve fixation of the joint prosthesis, and meanwhile a pretreated sample with the set angle and displacement condition is subjected to temperature setting and temperature setting to obtain a pre-treated sample; the device is installed on a material testing machine and then is connected with a contact pressure testing device so as to realize the testing of the contact pressure.

Description

Technical Field

[0001] The present invention belongs to the technical field of orthopedic implants, and particularly relates to a method and device for testing the contact pressure between joint prosthesis components. Background Art

[0002] One major concern in current arthroplasty is osteolysis caused by wear debris of joint prostheses. Early fatigue failure of the polyethylene material bearing surface used to make the liner is the main source of wear debris. There are many factors leading to wear, including stress (depending on the patient's body weight, activity, and prosthesis design), the number of cycles, and the properties of the polyethylene material. The movement between joint components is relatively complex because the movement of the joint surface includes both rolling and sliding. The rolling / sliding motion causes periodic tension and compression on the polyethylene surface of the joint and subsurface shear. Generally, the intensity of these stresses is directly affected by the surface contact pressure, and the contact stress is an important factor that greatly affects the implant design and surface wear. Bartel et al. gave suggestions that increasing the contact area and reducing the contact stress are very important. However, if the contact area is too large, resulting in low contact stress, it will limit the flexibility in the rotational fit of different components. If the contact area is reduced, it can avoid overconstraining the joint, but it may lead to loosening. Therefore, studying the magnitude of the contact pressure between joint components is an indicator for the success of clinical surgery and a key indicator for product design. Since the contact between the joint surfaces of each component of the joint prosthesis is a curved surface design, especially the contact surfaces of knee joint prostheses and ankle joint prostheses, which are irregular curved surfaces, the distribution of the contact pressure is non-uniform and discontinuous. There may be pressure points that are too concentrated in the entire contact surface area. These pressure concentration points are where wear is likely to occur. At the same time, considering that after the joint prosthesis is implanted into the human body, it is affected by the biomechanical properties of the human body and has different movement trajectories. For example, a knee joint prosthesis will be affected by some biomechanical factors such as flexion angle, internal and external rotation, anterior and posterior displacement, and bearing pressure load. Currently, there is no general method, equipment, or device at home and abroad to solve the above contact pressure testing problems. Summary of the Invention

[0003] In order to solve the above deficiencies in the prior art, the purpose of the present invention is to provide a method and device for testing the contact pressure between joint prosthesis components to solve the problems mentioned in the background art.

[0004] The technical solution adopted by the method and device for testing the contact pressure between joint prosthesis components to solve its technical problems is as follows: A method for testing the contact pressure between joint prosthesis components is provided, including: S1. Align and install the joint components on the testing machine and adjust the flexion angle in the sagittal plane; S2. Apply different axial loads; S3. Adjust the test loading time; S4. Regulate the influence of temperature setting; S5. Adjust different influencing factors according to different joints; S6. An evaluation scheme and indicators are given for the output of the results: Test of contact pressure: The entire joint surface of the joint prosthesis in the test area; Evaluation indicator: <21 MPa;.

[0005] Furthermore, among the flexion angles of the joint assembly, the preferred flexion angles of the knee joint prosthesis are 0°, 15°, 60° and 90°; the preferred flexion angles of the ankle joint prosthesis are 0°, 10°, 20°.

[0006] Furthermore, among the application of different axial loads, the loads that can be applied to the two joint prostheses are three times the body weight (2130 N), twice the body weight (1420 N) and the body weight (710 N).

[0007] Furthermore, the adjustment of the test loading time includes loading tests of 10 s, 30 s and 60 s under load.

[0008] Furthermore, the regulation of the influence of temperature setting is preferably 24 °C, 37 °C and 55 °C.

[0009] Furthermore, in S5, according to different joint prostheses, the adaptability adjustment of the knee joint prosthesis is the influencing factor of the internal rotation angle of 20°, while the adaptability adjustment of the ankle joint prosthesis is the influencing factor of the maximum anteroposterior displacement of 7 mm.

[0010] On the other hand, the present invention also provides a testing device for implementing the above testing method, including an upper joint prosthesis embedding fixture and a lower joint prosthesis embedding fixture. The upper joint prosthesis embedding fixture is driven by a flexion angle servo motor, and the flexion angle servo motor is fixedly installed on the testing machine. A flexion angle sensor is fixedly installed on the testing machine, and the flexion angle sensor is coaxially and fixedly connected to the upper joint prosthesis embedding fixture; the lower joint prosthesis embedding fixture is driven by a posterior tilt angle servo motor, and the posterior tilt angle servo motor is fixedly installed on the testing machine. A posterior tilt angle sensor is fixedly installed on the testing machine, and the posterior tilt angle sensor is coaxially and fixedly connected to the lower joint prosthesis embedding fixture. An internal rotation angle linear push rod is provided below the lower joint prosthesis embedding fixture. One end of the internal rotation angle linear push rod is fixedly connected to the bottom plate of the testing machine through a quick-release knot, and the other end is connected to the lower joint prosthesis embedding fixture through a quick-release knot. The lower joint prosthesis embedding fixture and the bottom plate of the testing machine are fixed together through a set of thrust bearings. When the internal rotation angle linear push rod is pushed out or retracted, it drives the lower joint prosthesis embedding fixture to rotate around the thrust bearing. An internal rotation angle visual monitoring system is fixedly installed on the testing machine, and several flexible resistive film pressure sensors are provided between the upper joint prosthesis embedding fixture and the lower joint prosthesis embedding fixture.

[0011] Further, it includes an upper joint prosthesis embedding fixture and a lower joint prosthesis embedding fixture. The upper joint prosthesis embedding fixture is driven by a flexion angle servo motor, and the flexion angle servo motor is fixedly installed on the testing machine. A flexion angle sensor is fixedly installed on the testing machine, and the flexion angle sensor is coaxially and fixedly connected to the upper joint prosthesis embedding fixture; the lower joint prosthesis embedding fixture is fixedly installed on the ball screw slider of the lead screw motion mechanism, and the lead screw motion mechanism is fixedly installed at the output end of the AP-direction displacement servo motor. The AP-direction displacement servo motor is fixedly installed on the internal rotation angle linear push rod connected through a quick-release knot, and the internal rotation angle linear push rod is fixedly installed on the bottom plate of the testing machine through a quick-release knot. The lower joint prosthesis embedding fixture is fixed on the bottom plate of the testing machine through a set of thrust bearings. An internal rotation angle visual monitoring system is fixedly installed on the testing machine, and several flexible resistive film pressure sensors are provided between the upper joint prosthesis embedding fixture and the lower joint prosthesis embedding fixture.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. For the method for testing the contact pressure between joint prosthesis components exemplified by the present invention, in this method, considering the above factors, since the flexion angle has the greatest influence on the joint contact area between components, the flexion angle is placed as the main influencing factor in the test method. At the same time, the flexion ranges of knee joint prostheses and ankle joint prostheses are investigated, and the flexion angle of the test is increased; Regarding the influencing factors of the loading load, it is considered that the joint prosthesis not only bears the influence of the human body's own weight, but also bears a weight exceeding the human body weight during movement and activities. Research has shown that when the contact stress exceeds the yield strength (21 MPa) of ultra-high molecular weight polyethylene (UHMWPE), which is approximately four times the load of the body weight, the incidence of pitting, delamination, and cracking is much higher. The latest research result by P. PROCTER gives the relationship between the axial load and the body weight in the literature, suggesting that the joint prosthesis needs to bear a load of 2.91 - 4.67 times the body weight. Therefore, we initially set three times the loading load (2130 N), twice the body weight (1420 N), and the body weight (710 N); The influence of temperature and time is also considered. For the influence of other factors such as angles and displacements, the internal rotation angle of 20° is generally considered for knee joint prostheses, and the maximum anteroposterior displacement of 7 mm is considered for ankle joint prostheses; We have given the setting of the above scheme parameters and also provided an evaluation scheme and indicators for the output of the results: Testing of contact pressure: The entire joint surface of the joint prosthesis in the test area; Evaluation indicator: < 21 MPa; Based on the innovation of the method, this patent needs to provide a pre-treatment test device and a contact pressure test device. The pre-treatment device can realize the setting of the flexion angle condition, internal rotation angle, and displacement distance, fix the joint prosthesis, and then install the pre-treated sample with the set angle and displacement conditions on the material testing machine and connect the contact pressure test device to achieve the testing of the contact pressure;

[0013] 2. The contact pressure testing device for the joint prosthesis components in the examples of the present invention can be applied to the pre-treatment of knee joint prostheses, can accurately adjust the internal rotation, flexion, and posterior tilt angles of the knee joint prosthesis, and a dynamic fatigue test under load is also required after the pre-treatment of the internal rotation, flexion, and posterior tilt angles. Among them, the posterior tilt angle of the tibial tray and the flexion angle of the femoral component are realized by two sets of servo motors + angle sensors; the internal rotation angle between the tibial tray and the femoral component is realized by a set of linear push rods + visual monitoring system, which can accurately adjust the internal rotation, flexion, and posterior tilt angles and provide real-time feedback for correction. Moreover, since the contact surface between the components of the joint prosthesis is a curved surface design and is irregular, in order to accurately measure the contact pressure at each point on the irregular curved surface without affecting the shape of the joint contact surface, a flexible resistive thin film pressure sensor is selected in this test method. The flexible resistive thin film pressure sensor can well meet the test requirements with its excellent flexibility, thinness, high sensitivity, etc. When in use, the flexible resistive thin film pressure sensor is pasted on different parts of the gasket of the sample to be tested, and tests are carried out according to the experimental factors such as the flexion angle, axial load, loading time, test temperature, etc. mentioned in the above test method to generate a force distribution diagram under different test factors. In addition, the test system has a function of importing pictures. Before the test, a schematic diagram of the size and shape of the sample to be tested can be imported into the test system, marked and numbered at the points to be tested, and then the thin film pressure sensor with the corresponding number is pasted on the corresponding points of the sample. Different test conditions are set for testing. After the test is completed, the force-bearing situation is output on the schematic diagram according to the monitored data, and the force distribution diagram on the surface of the sample can be intuitively seen.

[0014] 3. The contact pressure testing device for the joint prosthesis components in the examples of the present invention can be applied to the pretreatment of ankle joint prostheses, can accurately adjust the flexion angle, internal rotation angle and displacement of the ankle joint prosthesis, and a dynamic fatigue test under load should be carried out after the pretreatment of the flexion angle, internal rotation angle and displacement. Among them, the flexion angle of the tibial component is realized by a set of servo motors + encoders; the AP-direction displacement of the talus component is realized by a set of servo motors + lead screw motion mechanisms; the internal rotation angle between the tibial component and the talus component is realized by a set of linear push rods + visual monitoring systems, which can accurately adjust the flexion angle, internal rotation angle and displacement and give real-time feedback for correction. And because the joint surfaces in contact between the components of the joint prosthesis are designed as curved surfaces and are irregular, in order to accurately measure the contact pressure at each point on the irregular curved surface and not affect the shape of the joint contact surface, a flexible resistive film pressure sensor is selected in this test method. The flexible resistive film pressure sensor, with its excellent flexibility, thinness, high sensitivity and other characteristics, can well meet the test requirements. When in use, the flexible resistive film pressure sensor is pasted on different parts of the gasket of the sample to be measured, and tests are carried out according to the experimental factors such as the flexion angle, axial load, loading time, test temperature, etc. mentioned in the above test method to generate a force distribution diagram under different test factors. In addition, the test system has a function of importing pictures. Before the test, a schematic diagram of the size and shape of the sample to be measured can be imported into the test system, marked and numbered at the points to be tested, and then the film pressure sensor with the corresponding number is pasted on the corresponding points of the sample, different test conditions are set, and tests are carried out. After the test is completed, the force condition is output on the schematic diagram according to the monitored data, and the force distribution diagram on the surface of the sample can be intuitively seen. Description of the Drawings

[0015] By reading the detailed description of the non-restrictive embodiments with reference to the following drawings, other features, objects and advantages of the present application will become more obvious: Figure 1 It is a schematic diagram of the device in the first embodiment of the present invention; Figure 2 It is a schematic diagram of the device in the second embodiment of the present invention.

[0016] In the figure: 1. Flexion angle servo motor; 2. Flexion angle sensor; 3. Posterior tilt angle servo motor; 4. Posterior tilt angle sensor; 5. Internal rotation angle linear push rod; 6. Internal rotation angle visual monitoring system; 7. Upper joint prosthesis embedding fixture; 8. Lower joint prosthesis embedding fixture; 9. Flexible resistive film pressure sensor; 10. AP-direction displacement servo motor. Detailed Embodiment

[0017] The present application will be further described in detail below in conjunction with the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the relevant invention and are not intended to limit the invention. Additionally, it should be noted that for ease of description, only the parts related to the invention are shown in the drawings.

[0018] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present application will be described in detail below with reference to the drawings and embodiments.

[0019] Embodiment 1: As Figure 1 shown, this embodiment provides a method for testing the contact pressure between joint prosthesis components, including: S1. Align and install the joint components on the testing machine to adjust the flexion angle in the sagittal plane; S2. Apply different axial loads; S3. Adjust the test loading time; S4. Adjust the influence of temperature setting; S5. Adjust different influencing factors according to different joints; S6. An evaluation scheme and indicators are given for the output of the results: Testing of contact pressure: The entire joint surface of the joint prosthesis in the test area; Evaluation indicator: < 21 MPa.

[0020] In this embodiment, among the flexion angles of the joint components, the preferred flexion angles of the knee joint prosthesis are 0°, 15°, 60°, and 90°; the preferred flexion angles of the ankle joint prosthesis are 0°, 10°, and 20°.

[0021] In this embodiment, among the application of different axial loads, the loads that can be applied to the two types of joint prostheses are three times the body weight (2130 N), two times the body weight (1420 N), and the body weight (710 N).

[0022] In this embodiment, the adjustment of the test loading time includes performing loading tests for 10 s, 30 s, and 60 s under load.

[0023] In this embodiment, the adjustment of the influence of temperature setting is preferably 24 °C, 37 °C, and 55 °C.

[0024] In this embodiment, in S5, adjustment is performed according to different joint prostheses. The adaptability adjustment of the knee joint prosthesis is the influencing factor of an internal rotation angle of 20°, while the adaptability adjustment of the ankle joint prosthesis is the influencing factor of a maximum anteroposterior displacement of 7 mm.

[0025] On the other hand, this embodiment also provides a test device for implementing the above test method, which is characterized by including an upper joint prosthesis embedding fixture 7 and a lower joint prosthesis embedding fixture 8. The upper joint prosthesis embedding fixture 7 is driven by a flexion angle servo motor 1, and the flexion angle servo motor 1 is fixedly installed on the testing machine. A flexion angle sensor 2 is fixedly installed on the testing machine, and the flexion angle sensor 2 is coaxially and fixedly connected to the upper joint prosthesis embedding fixture 7. The lower joint prosthesis embedding fixture 8 is driven by a posterior tilt angle servo motor 3, and the posterior tilt angle servo motor 3 is fixedly installed on the testing machine. A posterior tilt angle sensor 4 is fixedly installed on the testing machine, and the posterior tilt angle sensor 4 is coaxially and fixedly connected to the lower joint prosthesis embedding fixture 8. An internal rotation angle linear push rod 5 is provided below the lower joint prosthesis embedding fixture 8. One end of the internal rotation angle linear push rod 5 is fixed to the bottom plate of the testing machine through a slip knot, and the other end is connected to the lower joint prosthesis embedding fixture 8 through a slip knot. The lower joint prosthesis embedding fixture 8 and the bottom plate of the testing machine are fixed together through a set of thrust bearings. When the internal rotation angle linear push rod 5 is pushed out or retracted, it drives the lower joint prosthesis embedding fixture 8 to rotate around the thrust bearing. An internal rotation angle visual monitoring system 6 is fixedly installed on the testing machine. Several flexible resistive film pressure sensors 9 are provided between the upper joint prosthesis embedding fixture 7 and the lower joint prosthesis embedding fixture 8. Specifically, in this embodiment, the number of flexible resistive film pressure sensors 9 is preferably 10.

[0026] In this method, considering the above factors, since the flexion angle has the greatest impact on the joint contact area between components, the flexion angle is placed as the main influencing factor in the test method. At the same time, the flexion range of motion of knee joint prostheses and ankle joint prostheses was investigated, and the flexion angle of the test was increased. Regarding the influencing factors of the applied load, it is considered that the joint prosthesis not only bears the influence of the human body's own weight, but also bears a weight exceeding the human body weight during movement and activity. Research has shown that when the contact stress exceeds the yield strength (21 MPa) of ultra-high molecular weight polyethylene (UHMWPE), which is approximately four times the load of the body weight, the incidence of pitting, delamination, and cracking is much higher. And the latest research result by P. PROCTER in the literature gives the relationship between the axial load and the body weight, believing that the joint prosthesis needs to bear a load of 2.91 - 4.67 times the body weight. Therefore, we initially set the applied load to three times (2130 N), two times (1420 N) of the body weight, and the body weight (710 N). The influence of temperature and time is also considered. For the influence of other angle and displacement factors, generally, the factor of an internal rotation angle of 20° is considered for knee joint prostheses, and the factor of a maximum anterior-posterior displacement of 7 mm is considered for ankle joint prostheses. We have given the setting of the above scheme parameters, and at the same time, an evaluation scheme and indicators are given for the output of the results: Test of contact pressure: The entire joint surface of the joint prosthesis in the test area Evaluation index: < 21 MPa; Based on the innovation of the method, this patent needs to provide a pre-treatment test device and a contact pressure test device. The pre-treatment device can realize the setting of the flexion angle condition, internal rotation angle and displacement distance, and fix the joint prosthesis. At the same time, the pre-treated sample with the set angle and displacement conditions is installed on the material testing machine, and then the contact pressure test device is connected to realize the test of the contact pressure; Based on the innovation of the method, this patent needs to provide a pre-treatment test device and a contact pressure test device. The pre-treatment device can realize the setting of the flexion angle condition, internal rotation angle and displacement distance, and fix the joint prosthesis. At the same time, the pre-treated sample with the set angle and displacement conditions is installed on the material testing machine, and then the contact pressure test device is connected to realize the test of the contact pressure; The test device of this embodiment can be applied to the pre-treatment of knee joint prostheses, can accurately adjust the internal rotation, flexion, and posterior tilt angles of the knee joint prostheses, and a dynamic fatigue test under load is also required after the pre-treatment of the internal rotation, flexion, and posterior tilt angles. Among them, the posterior tilt angle of the tibial tray and the flexion angle of the femoral component are realized by two sets of servo motors + angle sensors; the internal rotation angle between the tibial tray and the femoral component is realized by a set of linear push rods + visual monitoring system, which can accurately adjust the internal rotation, flexion, and posterior tilt angles and provide real-time feedback for correction. And because the contact surface of the joint between the components of the joint prosthesis is a curved surface design and is irregular, in order to accurately measure the contact pressure at each point of the irregular curved surface and not affect the shape of the joint contact surface, a flexible resistive film pressure sensor is selected in this test method. The flexible resistive film pressure sensor can well meet the test requirements with its excellent flexibility, thinness, high sensitivity, etc. When in use, the flexible resistive film pressure sensor 9 is pasted on different parts of the gasket of the sample to be tested, and tests are carried out according to the experimental factors such as the flexion angle, axial load, loading time, test temperature, etc. mentioned in the above test method to generate a force distribution diagram under different test factors. In addition, the test system has a function of importing pictures. Before the test, the size and shape schematic diagram of the sample to be tested can be imported into the test system, marked and numbered at the points to be tested, and then the film pressure sensor with the corresponding number is pasted on the corresponding points of the sample, different test conditions are set, and tests are carried out. After the test is completed, the force condition is output on the schematic diagram according to the monitored data, and the force distribution diagram on the surface of the sample can be intuitively seen.

[0027] Embodiment 2: The same features as those in Embodiment 1 will not be described in detail. The features different from those in Embodiment 1 in this embodiment are as follows Figure 2As shown in the figure, the test device of this embodiment includes an upper joint prosthesis embedding fixture 7 and a lower joint prosthesis embedding fixture 8. The upper joint prosthesis embedding fixture 7 is driven by a flexion angle servo motor 1. The flexion angle servo motor 1 is fixedly installed on the testing machine. A flexion angle sensor 2 is fixedly installed on the testing machine. The flexion angle sensor 2 is coaxially and fixedly connected to the upper joint prosthesis embedding fixture 7. The lower joint prosthesis embedding fixture 8 is fixedly installed on the ball screw slider of the screw motion mechanism. The screw motion mechanism is fixedly installed at the output end of the AP-direction displacement servo motor 10. The AP-direction displacement servo motor 10 is fixedly installed on the in-rotation angle linear push rod 5 connected by a slip knot. The in-rotation angle linear push rod 5 is fixedly installed on the testing machine base plate through a slip knot. The lower joint prosthesis embedding fixture 8 is fixed on the testing machine base plate through a set of thrust bearings. An in-rotation angle visual monitoring system 6 is fixedly installed on the testing machine. A plurality of flexible resistive film pressure sensors 9 are arranged between the upper joint prosthesis embedding fixture 7 and the lower joint prosthesis embedding fixture 8. Specifically, in this embodiment, the number of flexible resistive film pressure sensors 9 is preferably 10.

[0028] The test device of this embodiment can be applied to the pre-treatment of ankle joint prostheses, and can accurately adjust the flexion angle, in-rotation angle and displacement of the ankle joint prostheses. Moreover, after the pre-treatment of the flexion angle, in-rotation angle and displacement, a loading dynamic fatigue test is to be carried out. Among them, the flexion angle of the tibial component is realized by a set of servo motor + encoder; the AP-direction displacement of the talus component is realized by a set of servo motor + screw motion mechanism; the in-rotation angle between the tibial component and the talus component is realized by a set of linear push rod + visual monitoring system, which can accurately adjust the flexion angle, in-rotation angle and displacement and give real-time feedback for correction. And because the contact surface of the joints between the components of the joint prosthesis is a curved surface design and is irregular, in order to accurately measure the contact pressure at each point of the irregular curved surface and not affect the shape of the joint contact surface, flexible resistive film pressure sensors are selected in this test method. Flexible resistive film pressure sensors, with their excellent flexibility, thinness, high sensitivity and other characteristics, can well meet the test requirements. When in use, the flexible resistive film pressure sensors 9 are pasted on different parts of the pad of the sample to be tested, and tests are carried out according to the experimental factors such as the flexion angle, axial load, loading time, test temperature, etc. mentioned in the above test method to generate a force distribution diagram under different test factors. In addition, the test system has a function of importing pictures. Before the test, the schematic diagram of the size and shape of the sample to be tested can be imported into the test system, marked and numbered at the points to be tested, and then the film pressure sensors with corresponding numbers are pasted on the corresponding points of the sample. Different test conditions are set for testing. After the test is completed, the force condition is output on the schematic diagram according to the monitored data, and the force distribution diagram on the surface of the sample can be intuitively seen.

[0029] The above description is only a preferred embodiment of the present application and an explanation of the applied technical principles. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solutions formed by the specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the technical solutions formed by mutually replacing the above features with the technical features (but not limited to) having similar functions disclosed in the present application.

[0030] Except for the technical features described in the specification, the remaining technical features are known to those skilled in the art. To highlight the innovative features of the present invention, the remaining technical features are not described herein again.

Claims

1. A method for testing contact pressure between joint prosthesis components, characterized in that: include: S1. Align and install the joint assembly on the testing machine to adjust the flexion angle in the sagittal plane; S2, applying different axial loads; S3, adjust the test loading time; S4, adjust the temperature setting effect; S5. Adjust different influencing factors according to different joints; S6. Evaluation schemes and indicators are given for the output of results: Contact pressure test: the entire joint surface of the joint prosthesis in the test area; evaluation index: <21MPa.

2. The method for testing contact pressure between joint prosthesis components according to claim 1, characterized in that: Among the flexion angles of the joint components, the preferred flexion angles of the knee joint prosthesis are 0°, 15°, 60° and 90°; the preferred flexion angles of the ankle joint prosthesis are: 0°, 10°, 20°.

3. The method for testing contact pressure between joint prosthesis components according to claim 1, characterized in that: In the aforementioned application of different axial loads, the two joint prostheses can apply loads of three times the body weight (2130 N), twice the body weight (1420 N) and the body weight (710 N).

4. The method for testing contact pressure between joint prosthesis components according to claim 1, characterized in that: The adjustment test loading time includes loading tests under load for 10 s, 30 s and 60 s.

5. The method for testing contact pressure between joint prosthesis components according to claim 1, characterized in that: The preferred temperature settings for adjustment are 24°C, 37°C and 55°C.

6. The method for testing contact pressure between joint prosthesis components according to claim 1, characterized in that: In the above-mentioned S5, the adjustment is performed according to different joint prostheses. The adaptability of the knee joint prosthesis is adjusted to the influencing factor of the internal rotation angle of 20°, while the adaptability of the ankle joint prosthesis is adjusted to the influencing factor of the maximum anterior-posterior displacement of 7 mm.

7. A testing device for implementing the testing method according to any one of claims 1 to 6, characterized in that: It comprises an upper joint prosthesis embedding fixture 7 and a lower joint prosthesis embedding fixture 8, wherein the upper joint prosthesis embedding fixture 7 is driven by a flexion angle servo motor 1, which is fixedly mounted on a testing machine, on which a flexion angle sensor 2 is fixedly mounted, and the flexion angle sensor 2 is coaxially fixedly connected to the upper joint prosthesis embedding fixture 7; the lower joint prosthesis embedding fixture 8 is driven by a castor angle servo motor 3, which is fixedly mounted on a testing machine, on which a castor angle sensor 4 is fixedly mounted, and the castor angle sensor 4 is coaxially fixedly connected to the lower joint prosthesis embedding fixture 8, and the lower joint prosthesis embedding fixture 8 is driven by a castor angle servo motor 3, which is fixedly mounted on a testing machine, on which a castor angle sensor 4 is fixedly mounted, and the castor angle sensor 4 is coaxially fixedly connected to the lower joint prosthesis embedding fixture 8. An internal rotation angle linear push rod 5 is provided below the joint prosthesis embedding fixture 8, one end of the internal rotation angle linear push rod 5 is fixed to the bottom plate of the testing machine through a slipknot, and the other end is connected to the lower joint prosthesis embedding fixture 8 through a slipknot. The lower joint prosthesis embedding fixture 8 is fixed to the bottom plate of the testing machine through a set of thrust bearings. When the internal rotation angle linear push rod 5 is pushed out or retracted, the lower joint prosthesis embedding fixture 8 is driven to rotate around the thrust bearing. An internal rotation angle visual monitoring system 6 is fixedly installed on the testing machine, and several flexible resistive film pressure sensors 9 are provided between the upper joint prosthesis embedding fixture 7 and the lower joint prosthesis embedding fixture 8.

8. A testing device for implementing the testing method according to any one of claims 1 to 6, characterized in that: It includes an upper joint prosthesis embedding fixture 7 and a lower joint prosthesis embedding fixture 8. The upper joint prosthesis embedding fixture 7 is driven by a flexion angle servo motor 1, and the flexion angle servo motor 1 is fixedly installed on a testing machine. A flexion angle sensor 2 is fixedly installed on the testing machine, and the flexion angle sensor 2 is coaxially fixedly connected to the upper joint prosthesis embedding fixture 7; the lower joint prosthesis embedding fixture 8 is fixedly installed on a ball screw slider of a screw motion mechanism, and the screw motion mechanism is fixedly installed on the output end of an AP displacement servo motor 10, and the AP displacement servo motor 10 is fixedly installed on a linear push rod 5 connected to an internal rotation angle through a slipknot, and the internal rotation angle linear push rod 5 is fixedly installed on the bottom plate of the testing machine through a slipknot, and the lower joint prosthesis embedding fixture 8 is fixed on the bottom plate of the testing machine through a set of thrust bearings, and an internal rotation angle visual monitoring system 6 is fixedly installed on the testing machine, and a number of flexible resistive film pressure sensors 9 are arranged between the upper joint prosthesis embedding fixture 7 and the lower joint prosthesis embedding fixture 8.

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