Total knee joint prosthesis constraint degree testing tool

Abstract

The utility model relates to the technical field of pressure testing devices, in particular to a total knee joint prosthesis constraint degree testing tool which is fixed on a workbench of a tensile machine and comprises a fixing seat used for installing a tibia component and an adjusting seat used for installing a thighbone component, the fixing seat is arranged on the workbench, the adjusting seat is fixedly connected with a chuck of the tensile machine, and the adjusting seat is arranged on the workbench. The tibia assembly and the femur assembly are oppositely arranged, the workbench is further provided with a sliding rail for linear displacement of the fixing base, and one side of the fixing base is provided with a tension source used for driving the fixing base to move and enabling the tibia assembly on the fixing base to make contact with the femur assembly on the adjusting base. According to the total knee joint prosthesis constraint degree testing tool, through cooperation of the tensile machine for applying vertical pressure and the sliding seat for applying horizontal tensile force, two axial experiments are completed at a time, stress of load movement at different buckling angles is simulated, and the testing efficiency is effectively improved.

Description

Technical Field

[0001] This utility model relates to the field of pressure testing device technology, and in particular to a tooling for testing the constraint degree of a total knee joint prosthesis. Background Technology

[0002] A total knee prosthesis is a medical device used to treat serious knee joint diseases such as knee osteoarthritis. It replaces worn or damaged knee joint surfaces through surgery to relieve pain, improve knee joint function, and enhance patients' quality of life.

[0003] By testing the constraint performance of different prostheses using tooling, we provide surgeons with a detailed product performance database. This helps them select the most suitable total knee prosthesis for each patient based on their specific circumstances, such as bone structure, preoperative mobility, and expected postoperative activity, thereby improving surgical success rates and patient satisfaction. We can quantify the motion constraint performance of total knee prostheses under specific loading conditions, including tests on anterior-posterior knee movement, medial-lateral shear, rotational loosening, varus-valgus rotation, and joint dislocation constraint performance, providing a scientific basis for prosthesis design and improvement.

[0004] The People's Republic of China pharmaceutical industry standard YY / T 1765-2020 specifies the test method for the restraint of total knee arthroplasty. It outlines a method for quantifying the kinematic restraint of total knee arthroplasty by conducting in vitro tests on the inherent articular surface design profile under specific loading conditions. Specifically, this involves pressure testing at different flexion angles, applying a joint reaction force to a set value of 710N. However, some testing fixtures currently on the market have limitations and cannot fully meet the requirements of the aforementioned standard. This results in test results that cannot accurately reflect the restraint of total knee arthroplasty in actual use, thus affecting doctors' selection of prostheses and the direction of prosthesis design improvements. Utility Model Content

[0005] To address the lack of existing tooling in the market that meets industry standards for testing total knee joint prostheses, this invention provides a total knee joint prosthesis constraint testing tooling. By combining a tension machine that applies vertical pressure and a slide that applies horizontal tension, two axial tests can be completed in one go, simulating the force under load motion at different flexion angles, effectively improving testing efficiency.

[0006] This invention provides a total knee joint prosthesis constraint testing fixture, fixed to the worktable of a tension testing machine. It includes a fixed seat for mounting the tibial component and an adjustable seat for mounting the femoral component. The fixed seat is positioned on the worktable, and the adjustable seat is fixedly connected to the clamp of the tension testing machine. The tibial and femoral components are arranged opposite each other. A slide rail is also provided on the worktable for linear displacement of the fixed seat. A tension source is provided on one side of the fixed seat to drive its displacement, bringing the tibial component on the fixed seat into contact with the femoral component on the adjustable seat. Through the cooperation of the adjustable seat and the fixed seat, coupled with a constant 710N tension source, the force analysis of load motion under different flexion angles is simulated to meet the specific loading conditions of pharmaceutical industry standards.

[0007] Furthermore, the mounting base slides along a slide rail via a slider at its bottom, and the displacement direction of the mounting base along the slide rail is perpendicular to the action direction of the tension testing machine's chuck. Through the cooperation of the slider and the slide rail, the mounting base achieves smooth, linear movement on the worktable, ensuring precise horizontal displacement of the tibia assembly. This allows for accurate contact between the tibia and femoral components, improving the accuracy and stability of force transmission during testing.

[0008] Furthermore, the fixation base is L-shaped, with a slider located at the bottom of the horizontal plate of the fixation base, and the tibial component fixedly mounted on the vertical plate of the fixation base. This makes the installation of the tibial component more stable and facilitates adjustment of its alignment with the femoral component in space.

[0009] Furthermore, the adjustment seat includes a U-shaped bracket and an adjustment plate. The U-shaped bracket is adapted to the clamp of the tension testing machine via a mounting shaft. The adjustment plate is fixed inside the U-shaped bracket by bolts at both ends, and the femoral component is fixed to the side of the adjustment plate near the tibial component. The adjustment plate is stably set inside the U-shaped bracket by the bolts at both ends to simulate different knee flexion angles, providing load movement conditions at various angles for testing.

[0010] Furthermore, the adjustment plate is provided with several positioning holes for fixing the femoral component, and several angle holes for adjusting the angle of the adjustment plate are correspondingly opened on both sides of the U-shaped bracket. Scales are provided next to the angle holes, allowing operators to fix the adjustment plate by passing bolts through the appropriate angle holes according to the scale indications, thereby achieving precise simulation of the knee flexion angle.

[0011] Furthermore, a base plate is provided at the bottom of the slide rail. The base plate is adapted to the worktable through the mounting plate on it, so that the entire test fixture can be stably installed on the worktable. The adaptation between the mounting plate and the worktable enhances the stability of the fixture, reduces shaking and displacement during the test, and ensures the accuracy of the test results.

[0012] Furthermore, a bracket is provided on the outside of the workbench to fix the tension source. One end of the tension source is fixed to the bracket, and the other end is fixed to the fixing seat. The tension source transmits the tension to the tibial component, so that the tibial component is always subjected to a force that is close to the femoral component, thereby simulating the contact state and force situation between the tibia and femur during the movement of the human knee joint.

[0013] Furthermore, the tension source includes a pull rope and a counterweight. A guide wheel is installed on the top of the support, and a pull ring is installed on the fixed base. One end of the pull rope is fixed to the pull ring, and the other end is connected to the counterweight via the guide wheel. The arrangement of the pull rope and counterweight makes the application of tension more stable and adjustable.

[0014] The beneficial effects of this utility model are as follows:

[0015] This invention provides a constraint testing fixture for total knee joint prostheses. Through the cooperation of a tension testing machine and a tension source, the vertical pressure applied by the tension testing machine clamp and the horizontal displacement of the fixed seat act independently yet synergistically. This can more realistically simulate the complex stress conditions of the human knee joint under load at different flexion angles, providing more reliable data support for constraint testing of total knee joint prostheses and better meeting the stringent requirements of pharmaceutical industry standards for testing fixtures. Attached Figure Description

[0016] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the test fixture;

[0018] Figure 2 This is a schematic diagram of the fixed seat and the adjustable seat;

[0019] Figure 3 This is a first-angle exploded view;

[0020] Figure 4 This is a second-angle exploded view;

[0021] Figure 5 This is a schematic diagram showing the connection between the femoral and tibial components;

[0022] In the diagram: 1. Tibial assembly, 2. Fixation seat, 21. Slider, 22. Pull ring, 3. Femoral assembly, 4. Adjustment seat, 41. Adjustment plate, 42. Mounting shaft, 43. Bolt, 44. Positioning hole, 45. Angle hole, 5. Slide rail, 51. Base plate, 52. Mounting plate, 6. Bracket, 61. Pull rope, 62. Guide wheel. Detailed Implementation

[0023] The technical solution of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this utility model, but not all embodiments.

[0024] To more realistically simulate the complex stress conditions of the human knee joint under load at different flexion angles, a full knee joint prosthesis constraint testing fixture was designed and fixed to the worktable of a tensile testing machine, such as... Figure 1 and 5 As shown, the device includes a fixation seat 2 for mounting the tibial component 1 and an adjustment seat 4 for mounting the femoral component 3. The fixation seat 2 is mounted on a worktable, and the adjustment seat 4 is fixedly connected to the clamp of the tension testing machine. The tibial component 1 and the femoral component 3 are positioned opposite each other. The worktable also has a slide rail 5 for linear displacement of the fixation seat 2. A base plate 51 is mounted at the bottom of the slide rail 5, and the base plate 51 is adapted to the worktable via a mounting plate 52. A tension source is provided on one side of the fixation seat 2 to drive its displacement, bringing the tibial component 1 on the fixation seat 2 into contact with the femoral component 3 on the adjustment seat 4. During the test, the tension testing machine drives the adjustment seat 4 and the femoral component 3 to reciprocate up and down. Simultaneously, the tension source drives the fixation seat 2 and the tibial component 1 to linearly displace on the slide rail 5, bringing the tibial component 1 into contact with the femoral component 3 and applying a certain pressure. This simulates the complex stress conditions of the human knee joint under load at different flexion angles, thereby testing the constraint degree of the total knee joint prosthesis.

[0025] Preferably, the tension source includes a pull rope 61 and a counterweight. A guide wheel 62 is provided on the top of the support 6, and a pull ring 22 is provided on the fixed seat 2. One end of the pull rope 61 is fixed to the pull ring 22, and the other end is connected to the counterweight via the guide wheel 62. A support 6 for fixing the guide wheel 62 is provided outside the workbench. One end of the pull rope 61 is connected to the pull ring 22 on the fixed seat 2, and the other end passes around the guide wheel 62 and is connected to the counterweight. By pulling the pull rope 61 with the counterweight, the fixed seat 2 is moved linearly along the slide rail 5, thereby making the tibia component 1 on the fixed seat 2 and the femoral component 3 on the adjusting seat 4 in close contact. An adjusting plate 41 is provided on the adjusting seat 4. The adjusting seat 4 is fixedly connected to the clamp of the tension machine via a mounting shaft 42, so that the tension machine can stably apply axial pressure to the femoral component 3 on the adjusting seat 4, thereby generating friction between the closely contacting tibia component 1 and femoral component 3, simulating the force situation of the human knee joint in actual movement. When it is necessary to change the test angle, loosen bolt 43, adjust the adjusting plate 41 to the appropriate angle, and then tighten bolt 43 to fix it.

[0026] like Figure 2 As shown, specifically, the fixing seat 2 is L-shaped, with the slider 21 positioned at the bottom of the horizontal plate of the fixing seat 2. The tibia assembly 1 is fixedly mounted on the vertical plate of the fixing seat 2, i.e., the tibia assembly 1 is positioned on the side closest to the femoral assembly 3. The fixing seat 2 slides against the slide rail 5 via the slider 21 at its bottom. The displacement direction of the fixing seat 2 along the slide rail 5 is perpendicular to the action direction of the tension testing machine chuck. The slider 21 on the fixing seat 2 cooperates with the slide rail 5 to ensure that the fixing seat 2 can move smoothly and linearly, guaranteeing the accuracy and stability of the testing process.

[0027] like Figure 3 and 4 As shown, the adjustment seat 4 includes a U-shaped bracket and an adjustment plate 41. The U-shaped bracket is adapted to the clamp of the tension machine through the mounting shaft 42 on it, so that the tension machine can drive the adjustment seat 4 to move up and down stably. The adjustment plate 41 is fixed in the U-shaped bracket by bolts 43 at both ends. The femoral component 3 is fixed to the side of the adjustment plate 41 near the tibia component 1 by bolts, so that the tibia component 1 and the femoral component 3 are in close contact and generate force, simulating the force situation of the human knee joint under load movement at different flexion angles.

[0028] To simulate different flexion angles, the adjustment plate 41 is provided with several positioning holes 44 for fixing the femoral component 3. The U-shaped bracket has several angle holes 45 on both sides for adjusting the angle of the adjustment plate 41. By changing the installation angle of the adjustment plate 41 in the angle holes 45 of the U-shaped bracket, different flexion angles can be precisely set, which can simulate the flexion state of the human knee joint in various actual sports scenarios, obtain more comprehensive and accurate test data, and provide strong support for the performance evaluation of the total knee joint prosthesis. At the same time, the scale marked at the angle holes 45 makes the adjustment process more convenient and efficient for the operator, improving the efficiency and accuracy of the test work.

[0029] The above description is illustrative only and not restrictive of this utility model. Those skilled in the art will understand that many modifications, variations or equivalents can be made without departing from the spirit and scope defined by the appended claims, and all such modifications, variations or equivalents will fall within the protection scope of this utility model.

Claims

1. A fixture for testing the constraint degree of a total knee joint prosthesis, fixed on the worktable of a tensile testing machine, characterized in that: It includes a fixed seat (2) for mounting the tibial component (1) and an adjusting seat (4) for mounting the femoral component (3). The fixed seat (2) is set on the worktable, and the adjusting seat (4) is fixedly connected to the clamp of the tensioning machine. The tibial component (1) and the femoral component (3) are set opposite to each other. The worktable is also provided with a slide rail (5) for linear displacement of the fixed seat (2). A tension source is provided on one side of the fixed seat (2) for driving the fixed seat (2) to move so that the tibial component (1) on the fixed seat (2) and the femoral component (3) on the adjusting seat (4) come into contact.

2. The constraint test fixture for a total knee prosthesis of claim 1, wherein: The fixed seat (2) slides with the slide rail (5) through the slider (21) at its bottom. The displacement direction of the fixed seat (2) along the slide rail (5) is perpendicular to the action direction of the tension machine chuck.

3. The constraint test fixture for a total knee prosthesis of claim 2, wherein: The fixing seat (2) is L-shaped, the slider (21) is set at the bottom of the horizontal plate of the fixing seat (2), and the tibia assembly (1) is fixedly set on the vertical plate of the fixing seat (2).

4. The constraint test fixture for a total knee prosthesis of claim 1, wherein: The adjustment seat (4) includes a U-shaped bracket and an adjustment plate (41). The U-shaped bracket is adapted to the clamp of the tensioning machine via the mounting shaft (42) on it. The adjustment plate (41) is fixed in the U-shaped bracket by bolts (43) at both ends. The femoral component (3) is fixed on the side of the adjustment plate (41) near the tibial component (1).

5. The constraint test fixture for a total knee prosthesis of claim 4, wherein: The adjustment plate (41) is provided with several positioning holes (44) for fixing the femoral component (3), and several angle holes (45) for adjusting the angle of the adjustment plate (41) are provided on both sides of the U-shaped bracket.

6. The constraint test fixture for a total knee prosthesis of claim 1, wherein: The bottom of the slide rail (5) is provided with a base plate (51), which is adapted to the worktable through the mounting plate (52) on it.

7. The constraint test fixture of claim 1, wherein: The workbench is equipped with a bracket (6) for fixing the tension source. One end of the tension source is fixed to the bracket (6), and the other end is fixed to the fixed seat (2).

8. The constraint test fixture of claim 7, wherein: The pulling source includes a pull rope (61) and a counterweight. A guide wheel (62) is provided on the top of the bracket (6), and a pull ring (22) is provided on the fixed seat (2). One end of the pull rope (61) is fixed to the pull ring (22), and the other end is connected to the counterweight via the guide wheel (62).

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