An auxiliary testing device for the mechanical properties of ligament grafts

Abstract

This invention discloses an auxiliary testing device for the mechanical properties of ligament grafts, comprising: a femoral bionic component and a tibial bionic component; the femoral bionic component includes a first connector, a femoral prosthesis, and a first fixator; the first fixator is located on one side of the femoral prosthesis and is used to press one end of the ligament graft against the ligament attachment side of the femoral prosthesis; the tibial bionic component includes a second connector, a tibial prosthesis, and a second fixator; the tibial prosthesis includes a plateau portion and a unicompartmental portion of the tibia; a groove is formed on the top surface of the plateau portion, and the groove is located on one side of the unicompartmental portion of the tibia; the second fixator is disposed in the groove, and the second fixator is used to press the other end of the ligament graft against the side wall of the groove; the unicompartmental portion of the tibia abuts against the bottom of the femoral prosthesis. This invention clamps the ligament graft onto a knee joint bionic testing platform to simulate the in vivo service conditions of the ligament graft and assist in the evaluation of the mechanical properties of the ligament graft.

Description

Technical Field

[0001] This invention relates to the field of ligament graft mechanical performance testing technology, and in particular to an auxiliary testing device for ligament graft mechanical performance. Background Technology

[0002] Ligament reconstruction is an important treatment for cruciate ligament ruptures, and the mechanical properties of ligament grafts determine their long-term performance within the body. Due to limitations in clinical trials, in vitro mechanical property evaluation tests of ligament grafts have become a crucial method for studying their performance.

[0003] Currently, there are no clear standards for the mechanical performance and fatigue testing of ligament grafts. Most mechanical and fatigue testing devices for ligament grafts are still at the stage of simply stretching and breaking the grafts or subjecting them to repeated friction. However, there are clear standards for evaluating the friction and wear performance of knee joint prostheses, allowing friction and wear testing devices to effectively simulate the complex movements of the human knee joint. Furthermore, existing knee joint bionic testing platforms can not only accurately simulate the complex multi-degree-of-freedom movements of the knee joint but also adjust the parameters of each degree of freedom according to different needs, simulating various knee joint movements. Therefore, using a knee joint bionic testing platform for evaluating the mechanical performance of ligament grafts can not only improve the bionic nature of the test but also allow for the evaluation of the mechanical performance of ligament grafts under different testing conditions, making the results of the mechanical performance evaluation and lifespan prediction of ligament grafts more accurate. However, the existing clamps on knee joint bionic testing platforms cannot properly clamp the ligament grafts. Summary of the Invention

[0004] This invention provides an auxiliary testing device for the mechanical properties of ligament grafts, which solves the problem of clamping ligament grafts onto a knee joint bionic testing platform to simulate the in vivo service conditions of ligament grafts and assist in the evaluation of the mechanical properties of ligament grafts.

[0005] The present invention provides an auxiliary testing device for the mechanical properties of ligament grafts, comprising: a femoral bionic component and a tibial bionic component located below the femoral bionic component;

[0006] The femoral bionic component includes a first connector, a femoral prosthesis, and a first fixation member; a first end of the first connector is used to connect with a femoral actuator, and a second end of the first connector is connected with the femoral prosthesis and the first fixation member; the first fixation member is located on one side of the femoral prosthesis and is used to press one end of a ligament graft onto the ligament attachment side of the femoral prosthesis.

[0007] The tibial bionic component includes a second connector, a tibial prosthesis, and a second fixation member; the first end of the second connector is used to connect with a tibial actuator; the tibial prosthesis includes a plateau portion and a unicompartment of the tibial bone, and the second end of the second connector is connected to the plateau portion; the unicompartment of the tibial bone is disposed on the surface of the plateau portion, and a groove is formed on the surface of the plateau portion, the groove being located on one side of the unicompartment of the tibial bone;

[0008] A second fixing member is provided in the groove, which is used to press the other end of the ligament graft against the side wall of the groove; the unicompartment of the tibia abuts against the end of the femoral prosthesis away from the first connector.

[0009] Furthermore, both the first and second fixing members include a threaded hole and a threaded fastener. The threaded fastener passes through the threaded hole and is threadedly engaged with it. The end of the threaded fastener is used to press and fix the ligament graft when the threaded fastener is inserted into the threaded hole and rotated so that the threaded fastener moves along the axial direction of the threaded hole toward the side of the femoral prosthesis ligament attachment or the side wall of the tibial prosthesis groove.

[0010] Furthermore, the first and second fixing members also include a slide rail, a slider, and a locking member. The threaded hole and threaded fastener are disposed on the slider. The slider is slidably connected to the slide rail for adjusting the fixing position of the ligament graft on the ligament attachment side of the femoral prosthesis or the side wall of the tibial prosthesis groove. The locking member is connected to the slider and the slide rail respectively for fixing the slider on the slide rail.

[0011] Furthermore, the locking component includes an auxiliary block, at least one limiting component, and at least one clamping component. The auxiliary block is provided with at least one first through hole, and the slider is provided with a second through hole corresponding to the first through hole. The slider is disposed on one side of the slide rail, and the auxiliary block is disposed on the other side of the slide rail. The limiting component is used to pass through the first through hole and the second through hole and then cooperate with the clamping component to fix the auxiliary block and the slider on the slide rail.

[0012] Furthermore, both the first and second fixators are disposed on the ligament attachment side near the femoral prosthesis. The sliding path of the first fixator is parallel to the axis of the femoral prosthesis, and is used to adjust the angle between the ligament graft and the ligament attachment side of the femoral prosthesis when the slider of the first fixator slides along the sliding path of the first fixator. The sliding path of the second fixator is parallel to the direction of the shortest line connecting the femoral prosthesis and the first fixator, and is used to adjust the angle between the ligament graft and the platform surface when the slider of the second fixator slides along the sliding path of the second fixator.

[0013] Furthermore, the femoral prosthesis has a unicompartment of the femur at one end away from the first connector. The surface of the unicompartment of the femur that abuts against the unicompartment of the tibia is a convex curved surface, and the surface of the unicompartment of the tibia that abuts against the unicompartment of the femur is a concave curved surface that abuts against the convex curved surface. This is to help the flexion axis of the unicompartment of the femur to be collinear with the motor output shaft of the femoral actuator when the unicompartment of the femur is flexed.

[0014] The femoral prosthesis is located on the central symmetry line of the first connector, and the projection line of the unicompartmental flexion axis of the femur on the first connector coincides with the central symmetry line;

[0015] The projection surface of the first connector onto the second connector coincides with the second connector;

[0016] The groove of the tibial prosthesis is divided by the slide into a fixation area for fixing the ligament graft and an operation area for manipulating the threaded fastener and the limiting member. The fixation area is located in the middle of the second connector, and the operation area is located near the edge of the second connector.

[0017] Furthermore, it also includes a sleeve and a fastening member. The sides of the first connector and the second connector are both provided with annular grooves. The sleeve is sleeved on the outside of the first connector and the second connector. The fastening member is used to press the sleeve into the annular groove so that the sleeve, the first connector and the second connector form a sealed space for filling with lubricant.

[0018] Furthermore, the first connector, the second connector, the first fixator, the second fixator, the femoral prosthesis, and the tibial prosthesis are all made of anti-corrosion materials.

[0019] Furthermore, both the first and second fasteners are made of hard, corrosion-resistant materials.

[0020] Furthermore, the first connector, the second connector, the femoral prosthesis, and the tibial prosthesis are all made of lightweight, corrosion-resistant materials.

[0021] As can be seen from the above technical solutions, the present invention has the following advantages:

[0022] This invention simulates the movement of the tibia and femur by placing a femoral bionic component above a tibial bionic component, with the unicompartment of the femur abutting against the unicompartment of the tibia. A first connector is connected to the femoral actuator, and a second connector is connected to the tibial actuator. A first fixation member is placed on one side of the tibial prosthesis, pressing one end of the ligament graft onto the ligament attachment side of the femoral prosthesis, thus fixing one end of the simulated ligament to the intercondylar fossa of the femur. A groove is provided on the platform of the tibial prosthesis, and a second fixation member is placed within the groove, fixing the other end of the ligament graft to the side wall of the groove, thus fixing the other end of the simulated ligament to the intercondylar eminence of the tibia. The ligament graft is fixed to the tibial and femoral prostheses by pressing, avoiding damage to the prostheses and ligament grafts by the fixation member, allowing the prostheses and ligament grafts to be reused for multiple experiments. Therefore, this embodiment solves the problem of clamping ligament grafts onto a knee joint bionic testing platform, realizing the simulation of the ligament grafts' service in the body, and assisting in the evaluation of the mechanical properties of ligament grafts. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 A schematic diagram of the overall structure of an auxiliary testing device for the mechanical properties of ligament grafts provided in an embodiment of the present invention;

[0025] Figure 2 A schematic diagram of the femoral bionic component in an auxiliary testing device for the mechanical properties of ligament grafts provided in an embodiment of the present invention. Figure 1 ;

[0026] Figure 3 A schematic diagram of the femoral bionic component in an auxiliary testing device for the mechanical properties of ligament grafts provided in an embodiment of the present invention. Figure 2 ;

[0027] Figure 4 A schematic diagram of the tibial biomimetic component in an auxiliary testing device for the mechanical properties of ligament grafts provided in an embodiment of the present invention. Figure 1 ;

[0028] Figure 5 A schematic diagram of the tibial biomimetic component in an auxiliary testing device for the mechanical properties of ligament grafts provided in an embodiment of the present invention. Figure 2 ;

[0029] Figure 6 A schematic diagram illustrating the movement of the unicompartment of the femur and the unicompartment of the tibia in an auxiliary testing device for the mechanical properties of ligament grafts provided in an embodiment of the present invention;

[0030] Figure 7 The setting of femoral unicompartment flexion motion parameters during an experiment using an auxiliary testing device for the mechanical properties of a ligament graft provided in an embodiment of the present invention;

[0031] Figure 8 The setting of anterior-posterior displacement motion parameters of the unicompartment of the tibia during an experiment using an auxiliary testing device for the mechanical properties of a ligament graft provided in an embodiment of the present invention;

[0032] Figure 9 The parameters for tibial unicompartmental rotational motion are set when conducting experiments with an auxiliary testing device for the mechanical properties of a ligament graft provided in an embodiment of the present invention.

[0033] Explanation of reference numerals in the attached drawings: 1. First connector; 2. Femoral prosthesis; 21. Unicompartment of femur; 3. First fixation member; 4. Second connector; 5. Tibial prosthesis; 51. Plateau portion; 52. Unicompartment of tibia; 53. Groove; 6. Second fixation member; 7. Screw; 8. Bolt; 9. Slide rail; 10. Slider; 11. Auxiliary block; 12. Nut; 14. Ligament graft; 15. Annular groove; 16. Slide rail fixation member. Detailed Implementation

[0034] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0035] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the present application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0036] Please see Figures 1-5 The present invention provides an auxiliary testing device for the mechanical properties of ligament grafts, comprising: a femoral bionic component and a tibial bionic component located below the femoral bionic component;

[0037] The femoral bionic component includes a first connector 1, a femoral prosthesis 2, and a first fixation member 3; the top of the first connector 1 is used to connect with the femoral actuator, and the bottom of the first connector 1 is connected with the femoral prosthesis 2 and the first fixation member 3; the first fixation member 3 is located on one side of the femoral prosthesis 2 and is used to press one end of the ligament graft 14 against the ligament attachment side of the femoral prosthesis 2.

[0038] The tibial bionic component includes a second connector 4, a tibial prosthesis 5, and a second fixation member 6; the bottom of the second connector 4 is used to connect with the tibial actuator; the tibial prosthesis 5 includes a plateau portion 51 and a unicompartmental tibial portion 52, and the top of the second connector 4 is connected to the plateau portion 51; the unicompartmental tibial portion 52 is disposed on the top surface of the plateau portion 51, and a groove 53 is formed on the top surface of the plateau portion 51, the groove 53 being located on one side of the unicompartmental tibial portion 52;

[0039] A second fixing member 6 is provided in the groove 53. The second fixing member 6 is used to press the other end of the ligament graft 14 against the side wall of the groove 53.

[0040] The femoral prosthesis 2 has a femoral unicompartment 21 at its bottom, which is used to abut against the tibial unicompartment 52.

[0041] Understandably, in practice, the femoral bionic component is positioned above the tibial bionic component, with the femoral unicompartment 21 abutting against the tibial unicompartment 52. The first connector 1 is connected to the femoral actuator, and the second connector 4 is connected to the tibial actuator, thus simulating the movement process of the tibia and femur. By placing the first fixation member 3 on one side of the tibial prosthesis 5, the first fixation presses one end of the ligament graft 14 to the ligament attachment side of the femoral prosthesis 2, thus simulating the fixation of one end of the ligament graft 14 to the femur. The intercondylar fossa; by setting a groove 53 in the platform portion 51 of the tibial prosthesis 5, and setting a second fixation member 6 in the groove 53, the second fixation member 6 fixes the other end of the ligament graft 14 to the side wall of the groove 53, thereby simulating the other end of the ligament graft 14 being fixed to the intercondylar eminence of the tibia; by pressing, the ligament graft 14 is fixed to the tibial prosthesis 5 and the femoral prosthesis 2, avoiding damage to the prosthesis and ligament graft 14 by the fixation member, so that the prosthesis and ligament graft 14 can be reused for multiple tests. Therefore, this embodiment solves the problem of clamping the ligament graft 14 on the knee joint bionic test platform, so as to realize the simulation of the service of the ligament graft 14 in the body, and assist in the mechanical performance evaluation test of the ligament graft 14.

[0042] It needs to be further explained that:

[0043] First, in the human body, the femur is located above the tibia, and the lower end of the femur connects to the tibia. Since there are currently no clear standards for the mechanical performance evaluation test of ligament graft 14, in order to improve the biomimetic performance of the mechanical performance evaluation test of ligament graft 14 and to conduct mechanical performance testing of ligament graft 14 under conditions that simulate knee joint movement as much as possible, when the mechanical performance evaluation test of ligament graft 14 is conducted on the knee joint biomimetic test platform, the relevant parameters of each degree of freedom of the test platform refer to the relevant parameters of each degree of freedom of the knee joint friction and wear test machine in the People's Republic of China Pharmaceutical Industry Standard (YY / T 1426.3—2017 / ISO 14243-3:2014) "Part 3: Load and displacement parameters and related test environment conditions for displacement-controlled wear testing machines". Among them, the relevant industry standard provides relevant parameters for four degrees of freedom: anterior-posterior displacement, tibial rotation, femoral flexion and axial force. Since the mechanical performance evaluation test of ligament graft 14 does not involve the evaluation of the friction and wear performance of the knee joint prosthesis, the axial force degree of freedom, which mainly affects the friction and wear state of the knee joint, only needs to ensure that the unicompartment of the femur and the unicompartment of the tibia can maintain contact during the test. The other three degrees of freedom, such as Figure 6 As shown, the three main degrees of freedom affecting the movement trajectory of the knee joint prosthesis—anterior-posterior displacement, tibial rotation, and femoral flexion—are set with reference to the values ​​in relevant industry standards to ensure the biomimetic degree of simulation of human knee joint movement during the ligament graft biomechanical evaluation test.

[0044] In the device of this embodiment, the femoral bionic component is located above the tibial bionic component. Since the knee joint bionic test platform cannot form an effective knee joint movement trajectory when there is no contact between the femoral end and the tibial end, the bottom of the femoral prosthesis 2 is provided with a femoral unicompartment 21, which abuts against the tibial unicompartment 52. The bottom surface of the femoral unicompartment 21 is an arc-shaped convex surface, and the top surface of the tibial unicompartment 52 is an arc-shaped concave surface that matches the arc-shaped convex surface. The femoral unicompartment 21 and the tibial unicompartment 52 cooperate to abut against the actuator of the knee joint bionic test platform to realize the simulation of the movement process of the tibia and femur.

[0045] Second, the knee joint bionic testing platform is equipped with a femoral actuator and a tibial actuator. The femoral actuator is used to drive the femoral bionic component to simulate femoral flexion movement, and the tibial actuator is used to drive the tibial bionic component to simulate anteroposterior displacement and tibial rotation. Therefore, the femoral bionic component is equipped with a first connector 1, the top of which is used to connect with the femoral actuator, so that the femoral actuator drives the first connector 1 to rotate, thereby enabling the femoral prosthesis 2 and the first fixation 3 to perform flexion movements synchronously; the femoral-tibial bionic component is equipped with a second connector 4, the bottom of which is used to connect with the tibial actuator, so that the tibial actuator drives the tibial prosthesis 5 and the second fixation 6 to perform anteroposterior displacement and rotation movements synchronously.

[0046] Third, in the human body, ligaments connect the tibia and femur, such as the anterior cruciate ligament (ACL), which connects the intercondylar fossa of the femur to the intercondylar eminence of the tibia. These ligaments play an important role in maintaining the stability of the knee joint. The ACL extends from the medial aspect of the lateral femoral condyle to the anterior intercondylar region of the tibia, preventing excessive anterior sliding of the tibia (anterograde instability) and limiting hyperextension and rotation of the knee joint.

[0047] On the one hand, in this embodiment, the bottom of the first connector 1 is connected to the femoral prosthesis 2 and the first fixation member 3. The first fixation member 3 is located on one side of the femoral prosthesis 2 and is used to press the ligament graft 14 onto the ligament attachment side of the femoral prosthesis 2, so as to fix one end of the simulated ligament to the intercondylar fossa of the femur.

[0048] On the other hand, in this embodiment, the tibial prosthesis 5 includes a platform portion 51 and a unicompartmental tibial portion 52. The top of the second connector 4 is connected to the platform portion 51. The unicompartmental tibial portion 52 is disposed on the top surface of the platform portion 51. A groove 53 is provided on the top surface of the platform portion 51. The groove 53 is located on one side of the unicompartmental tibial portion 52 to simulate the tibial structure. A second fixation member 6 is provided in the groove 53. The second fixation member 6 is used to press the other end of the ligament graft 14 against the side wall of the groove 53 of the tibial prosthesis 5 to fix the other end of the simulated ligament to the intercondylar eminence of the tibia.

[0049] Therefore, in this embodiment, the ligament graft 14 is pressed onto the ligament attachment side of the femoral prosthesis 2, and the other end of the ligament graft 14 is pressed onto the side wall of the groove 53 of the tibial prosthesis 5. The tibial actuator and femoral actuator of the knee joint bionic test platform control the anterior and posterior displacement, rotation and flexion movement of the tibia respectively. By conducting experiments on the ligaments through the device of this embodiment, the simulation of the anterior cruciate ligament's service in the body can be achieved.

[0050] Fourth, by pressing, the ligament graft 14 is fixed to the tibial prosthesis 5 and the femoral prosthesis 2. On the one hand, this avoids damage to the prosthesis by the fixation device, allowing the prosthesis to be reused for multiple tests. On the other hand, it ensures that the attachment point of the ligament graft 14 is fixed on the prosthesis and maintains the tension of the ligament graft 14, allowing the ligament graft 14 to be reused for multiple tests.

[0051] In a more specific embodiment, both the first fixing member 3 and the second fixing member 6 include a threaded hole and a threaded fastener. In this embodiment, the threaded fastener is a screw 7. The middle part of the screw 7 passes through the threaded hole and is threadedly engaged with the threaded hole. The bottom of the screw 7 is used to press the ligament graft 14 when the screw 7 is inserted into the threaded hole and rotated so that the screw 7 moves along the axial direction of the threaded hole closer to the side of the femoral prosthesis 2 or the side wall of the groove 53 of the tibial prosthesis 5.

[0052] Understandably, in practice, the screw 7 and the threaded hole tighten and loosen through the interaction of the helical structure of the thread and friction, converting the rotational motion between the screw 7 and the threaded hole into axial linear motion. When the screw 7 is inserted into the threaded hole and rotates, it moves along the axial direction of the threaded hole and gradually locks, thereby pressing and fixing the ligament graft 14 to the ligament attachment side of the femoral prosthesis 2 or the sidewall of the groove 53 of the tibial prosthesis 5. On one hand, in ligament transplantation surgery, the interface screw 7 fixes the ligament graft 14 to the femur and tibia. This scheme uses screw 7 for fixation, which can fully simulate the fixation method of the ligament graft 14 in the human body. On the other hand, the threaded transmission is converted into pressure that fixes the ligament graft 14 to the surface of the prosthesis. During the rotation of the screw 7, the axial displacement distance of the screw 7 can be precisely controlled, thereby precisely controlling the pressure of the screw 7 on the ligament attachment side of the femoral prosthesis 2 or the sidewall of the groove 53 of the tibial prosthesis 5, avoiding damage to the femoral prosthesis 2 and the tibial prosthesis 5.

[0053] It should be noted that in the human body, the base of the femur connects to two femoral condyles, forming an intercondylar fossa, within which one end of the cruciate ligament is positioned. Similarly, the top of the tibia connects to two tibial condyles, forming an intercondylar fossa, with the anterior cruciate ligament positioned anterior to the intercondylar eminence. Since the dimensions of the femur and tibia, the width of the intercondylar fossa, and the intercondylar fossa itself vary from individual to individual, in cases of narrow intercondylar fossae, one end of the ligament graft 14 needs to be positioned high on the femoral side, near the upper part of the intercondylar fossa, to reduce the angle between the ligament graft 14 and the connected femoral side, preventing collision and wear between the ligament graft 14 and the other femoral condyle. Similarly, in cases of narrow tibial intercondylar fossae, the other end of the ligament graft 14 needs to be fixed near the tibial condyle on the same side as the connected femur. Therefore, this implementation device achieves the adjustment of the attachment point position of the ligament graft 14 through the following embodiments.

[0054] In a more specific embodiment, the first fixing member 3 and the second fixing member 6 further include a slide rail 9, a slider 10 and a locking member. Threaded holes and screws 7 are disposed on the slider 10. The slider 10 is slidably connected to the slide rail 9 to adjust the fixing position of the ligament graft 14 on the ligament attachment side of the femoral prosthesis 2 or the side wall of the groove 53 of the tibial prosthesis 5. The locking member is connected to the slider 10 and the slide rail 9 respectively to fix the slider 10 on the slide rail 9.

[0055] Understandably, in practice, by manipulating the slider 10 to move along the slide rail 9, and after the slider 10 reaches the target position, the locking device re-fixes the slider 10 onto the slide rail 9. Because the position of the slider 10 changes, the positions of the threaded holes and screws 7 on the slider 10 also change, thereby altering the position of pressing and fixing the ligament graft 14. In this way, the fixing position of the ligament graft 14 on the ligament attachment side of the femoral prosthesis 2 or on the side wall of the groove 53 of the tibial prosthesis 5 is adjusted, making the attachment point position of the ligament graft 14 on the femoral prosthesis 2 and the tibial prosthesis 5 adjustable. In simulation experiments, this device can adjust the position of the ligament graft 14 on the femoral prosthesis 2 and the tibial prosthesis 5 based on individual bone size and structural differences, making the simulated movement of the ligament graft 14 more closely resemble real-world conditions. The movement of the slider 10 along the slide rail 9 provides relatively precise position adjustment, accurately fixing the ligament graft 14 in the desired position.

[0056] In a more specific embodiment, the locking component includes an auxiliary block 11, at least one limiting component, and at least one clamping component. In this embodiment, the limiting component is a bolt 8, and the clamping component is a nut 12. The auxiliary block 11 is provided with at least one first through hole, and the slider 10 is provided with a second through hole corresponding to the first through hole. The slider 10 is provided on one side of the slide rail 9, and the auxiliary block 11 is provided on the other side of the slide rail 9. The bolt 8 is used to pass through the first through hole and the second through hole and then cooperate with the nut 12 to fix the auxiliary block 11 and the slider 10 on the slide rail 9.

[0057] Understandably, in practice, on the one hand, when it is necessary to change the fixation point of the ligament graft 14 to another fixation point, by slightly loosening the nut 12, the auxiliary block 11 and the slider 10 will loosen at the slide rail 9, allowing the auxiliary block 11 and the slider 10 to be moved together as a whole, without having to completely remove the slider 10 from the slide rail 9, thus achieving convenient replacement of the fixation point of the ligament graft 14. On the other hand, the slider 10 and the slide rail 9 can be separated, so when the threads of the threaded hole on the slider 10 are worn, the slider 10 can be replaced, effectively improving replacement efficiency and reducing maintenance costs.

[0058] In a more specific embodiment, the auxiliary block 11 is provided with a first through hole, the slider 10 is provided with a second through hole, the slide rail 9 is a rectangular hollow track, the slider 10 is located on one side of the hollow track, and the auxiliary block 11 is located on the other side of the hollow track. The first through hole and the second through hole are coaxially arranged. The bolt 8 is used to pass through the first through hole, the middle of the rectangular track, and the second through hole, and then cooperates with the nut 12 to fix the auxiliary block 11 and the slider 10 on the hollow track. It can be understood that in a specific implementation, the bolt 8 is set inside the hollow track, and only one first through hole, one bolt 8, and one nut 12 are needed to fix the slider 10 and the auxiliary block 11, effectively simplifying the locking structure.

[0059] In a more specific embodiment, the slider 10 includes a first embedding part and a first abutting part, which are connected to each other. The auxiliary block 11 includes a second embedding part and a second abutting part, which are connected to each other. The first embedding part and the second embedding part are disposed within the hollow track. The two sides of the second embedding part and the second abutting part respectively contact the two sides of the track, so as to realize the slider 10 and the auxiliary block 11 sliding stably along the hollow track. When the first embedding part and the second embedding part are disposed within the hollow track, a gap is provided between them to provide space for the bolt 8 and the nut 12 to press the auxiliary block 11 and the slider 10. The first abutting part and the second abutting part respectively abut against the outer frame edge of the hollow track. When the bolt 8 and the nut 12 are tightened, the first abutting part and the second abutting part press against the outer frame edge of the hollow track from both sides, thereby fixing the slider 10 on the hollow track.

[0060] In a more specific embodiment, the auxiliary block 11 is provided with a third through hole corresponding to the threaded hole. The third through hole is used to pass through the screw 7, which is located in the hollow track, which is beneficial for supporting the screw 7 and improving the stability of the screw 7.

[0061] In a more specific embodiment, the bolt 8 of the first fixation member 3 is located on the side close to the first connector 1, and the screw 7 of the first fixation member 3 is located on the side away from the first connector, that is, the screw 7 is located below the bolt 8; the bolt 8 of the first fixation member 3 is located on the side close to the unicompartment 52 of the tibia, and the screw 7 of the first fixation member 3 is located on the side away from the unicompartment 52 of the tibia. It can be understood that the aforementioned arrangement of the screw 7 and bolt 8 provides sufficient positioning space for the ligament graft 14.

[0062] It should be noted that the slider 10 and auxiliary block 11 of the first fixation component 3 slide in a rectangular hole inside a rectangular hollow track, perpendicular to the bottom surface of the first connection. The slider 10 and auxiliary block 11, sliding within the rectangular hole of the hollow track, can adjust the fixation position of the ligament graft 14 on the femoral prosthesis 2 according to experimental needs. After determining the fixation position of the ligament graft 14 at the femoral end, tighten the bolt 8 on the slider 10 to clamp the slider 10 and auxiliary block 11 into the hollow track, thus fixing the slider 10 and auxiliary block 11 on the hollow track. Then, tighten the screw 7 below the slider 10 to fix the ligament graft 14 to the ligament attachment side of the femoral prosthesis 2. The fixation method of the ligament graft 14 on the tibial prosthesis 5 is the same as that on the femoral prosthesis 2, and will not be described in detail here.

[0063] In a more specific embodiment, both the first fixation member 3 and the second fixation member 6 are disposed on the ligament attachment side near the femoral prosthesis 2. The slide path 9 of the first fixation member 3 is parallel to the axis of the femoral prosthesis 2, and is used to adjust the angle between the ligament graft 14 and the ligament attachment side of the femoral prosthesis 2 when the slider 10 of the first fixation member 3 slides along the slide path 9 of the first fixation member 3. The slide path 9 of the second fixation member 6 is parallel to the direction of the shortest line connecting the femoral prosthesis 2 and the first fixation member 3, and is used to adjust the angle between the ligament graft 14 and the plane of the platform portion 51 when the slider 10 of the second fixation member 6 slides along the slide path 9 of the second fixation member 6.

[0064] Understandably, in specific implementation, the sliding path of the slide 9 of the first fixation member 3 is parallel to the axis of the femoral prosthesis 2, so that the attachment point of the ligament graft 14 is adjusted along the height direction of the ligament attachment side of the femoral prosthesis 2, thereby adjusting the angle between the ligament graft 14 and the ligament attachment side of the femoral prosthesis 2. When the slider 10 of the first fixation member 3 moves towards the direction of the first connector 1, the angle between the ligament graft 14 and the ligament attachment side of the femoral prosthesis 2 becomes smaller. When the slider 10 of the first fixation member 3 moves towards the direction of the second connector 4, the angle between the ligament graft 14 and the ligament attachment side of the femoral prosthesis 2 becomes larger. On the other hand, the slide 9 of the second fixation member 6 is set along the shortest line connecting the first fixation member 3 and the femoral prosthesis 2. By adjusting the position of the slider 10 of the second fixation member 6 in the slide 9, the attachment point of the ligament graft 14 at the tibial end can be closer to or further away from the unicompartment 52 of the tibia. Thus, when the slider 10 of the second fixation member 6 slides along the slide 9 of the second fixation member 6, the angle between the ligament graft 14 and the plane of the plateau portion 51 can be adjusted. When the slider 10 of the second fixation member 6 moves closer to the unicompartment 52 of the tibia, the angle between the ligament graft 14 and the ligament attachment side of the femoral prosthesis 2 becomes larger. When the slider 10 of the second fixation member 6 moves further away from the unicompartment 52 of the tibia, the angle between the ligament graft 14 and the ligament attachment side of the femoral prosthesis 2 becomes smaller. The aforementioned angle adjustment method allows for targeted adjustments to the position of the ligament graft 14 on the femoral prosthesis 2 and tibial prosthesis 5, taking into account individual differences in bone size and structure and avoiding collision and wear between the ligament graft 14 and the femoral condyle on the other side. Through this personalized adjustment, the performance of the ligament graft 14 in simulated movement can more closely resemble actual conditions.

[0065] In addition, by setting both the first fixation member 3 and the second fixation member 6 on the ligament attachment side near the femoral prosthesis 2, the first fixation member 3 is positioned above the second fixation member 6, so that the entire ligament graft 14 is located on the same side of the femoral prosthesis 2, thereby simulating the anterior cruciate ligament located in front of the intercondylar fossa of the femur and the intercondylar eminence of the tibia.

[0066] In a more specific embodiment, the hollow track is a rectangular track, and the slider 10 moves parallel to the length of the rectangular track. This parallel movement helps to precisely adjust the angle between the ligament graft 14 and the ligament attachment surface of the femoral prosthesis 2, as well as the plane of the platform portion 51 of the tibial prosthesis 5.

[0067] In a more specific embodiment, the first fixation member 3 further includes a slide fixation member 16, the side of the slide 9 of the first fixation member 3 is connected to the side of the slide fixation member 16, and the first connector 1 is connected to the femoral prosthesis 2 and the slide fixation member 16 by countersunk screws.

[0068] In a more specific embodiment, the bottom surface of the femoral unicompartment 21 is a convex curved surface, and the top surface of the tibial unicompartment 52 is a concave curved surface corresponding to the convex curved surface, which is used to assist the femoral unicompartment 21 in having its flexion axis collinear with the motor output shaft of the femoral actuator during flexion movement.

[0069] It should be noted that in the knee joint bionic test platform, the motors of the femoral actuator are located on both sides of the unicompartment 21 of the femur. The motors are connected to the top of the first connector 1 in sequence through a vertical drive rod and a horizontal drive rod. When the motor rotates, it drives the vertical drive rod, which in turn drives the horizontal drive rod to swing. The first connector 1 is connected to the horizontal drive rod, thereby causing the first connector 1 to rotate around the motor output shaft and the flexion axis of the unicompartment 21 of the femur. This allows the unicompartment 21 of the femur to rotate around the flexion axis without the motor output shaft being directly connected to the unicompartment 21 of the femur, thus accurately simulating the flexion and rotation process of the femur.

[0070] In a more specific embodiment, the projection line of the flexion axis of the unicompartment 21 of the femur coincides with the symmetry line of the bottom surface of the first connector 1. The femoral prosthesis 2 and the unicompartment 21 of the femur are symmetrically distributed along the symmetry line of the bottom surface of the first connector 1, that is, the femoral prosthesis 2 is located on the symmetry line at the middle of the bottom surface of the first connector 1, and the projection line of the flexion axis of the unicompartment 21 of the femur coincides with the symmetry line at the middle of the bottom surface of the first connector 1. It can be understood that when the first connector 1 is connected to the horizontal drive rod, it is sufficient to ensure that the symmetry line of the first connector 1 is aligned with the horizontal centerline of the horizontal drive rod, thereby improving the positioning efficiency of the unicompartment 21 of the femur and the motor output shaft.

[0071] In a more specific embodiment, the projection surface of the first connector 1 onto the second connector 4 coincides with the top surface of the second connector 4.

[0072] Understandably, in specific implementation, the femoral prosthesis 2 and the femoral unicompartment 21 are fixed on the first connection based on the fact that the projection plane of the first connector 1 onto the second connector 4 coincides with the top surface of the second connector 4, and the position of the tibial unicompartment 52 is fixed on the second connection. When reused, the positioning of the femoral unicompartment 21 and the tibial unicompartment 52 can be completed by judging whether the first connector 1 and the second connector 4 coincide on the projection plane, which significantly improves the positioning efficiency.

[0073] In a more specific embodiment, the groove 53 of the tibial prosthesis 5 includes a fixation area for fixing the displacement of the ligament graft and an operation area for rotating the screws 7 and bolts 8. The fixation area and the operation area are separated by a slide 9. The fixation area is located in the middle of the second connector 4, and the operation area is located near the edge of the second connector 4.

[0074] Understandably, in practice, by setting the fixation area in the middle of the second connector 4, corresponding to the attachment point of the ligament graft 14 of the femoral prosthesis 2, and considering the small projected distance between the attachment point of the ligament graft 14 on the femoral prosthesis 2 and the attachment point on the tibial prosthesis 5 in the second connector 4, the fixation area is set in the middle of the connector. By setting the operating area near the edge of the second connector 4, it is convenient to operate the screws 7 and helices on the slider 10.

[0075] In a more specific embodiment, since the anterior cruciate ligament is located anterior to the tibial intercondylar eminence, the anteroposterior width of the groove 53 is greater than the anteroposterior width of the tibial unicompartmental prosthesis. The ligament graft 14 can be fixed to the sidewall surface of the fixation area of ​​the groove 53.

[0076] In a more specific embodiment, the sides of the first connector 1 and the second connector 4 are provided with an annular groove 15. The annular groove 15 is used to press the sleeve into the annular groove 15 by the tightening member when the sleeve is sequentially fitted onto the first connector 1 and the second connector 4, so that the sleeve, the first connector 1 and the second connector 4 form a sealed space for filling with lubricant.

[0077] In a more specific embodiment, the sleeve is a telescopic flexible hose, and the fastening element is a sealing buckle.

[0078] In a more specific embodiment, both the first connector 1 and the second connector 4 are discs, and the outer diameters of the first connector 1 and the second connector 4 are equal. After a telescopic hose is provided on the outside of the first connector 1 and the second connector 4, it is sealed by a sealing buckle. Lubricating fluid is added inside the telescopic hose to simulate the body fluid environment inside the human body for mechanical performance evaluation tests of the ligament graft 14.

[0079] It should be noted that, in specific implementation, the telescopic hose is sequentially fitted onto the outside of the first connector 1 and the second connector 4. First, one end of the telescopic hose is pressed into the annular groove 15 of the second connector 4 through the sealing buckle to achieve a seal. Lubricant is added into the telescopic hose from the other end. Then, the other end of the telescopic hose is pressed into the annular groove 15 of the first connector 1 through the sealing buckle to achieve a seal. This ensures that the femoral prosthesis 2, tibial prosthesis 5, and ligament graft 14 are all in a simulated human body fluid environment.

[0080] In a more specific embodiment, the first connector 1, the second connector 4, the first fixation member 3, the second fixation member 6, the femoral prosthesis 2, and the tibial prosthesis 5 are all made of corrosion-resistant materials. This allows the device to better withstand the corrosive effects of the simulated body fluid environment during the test, making the simulation of the human body fluid environment in the mechanical performance evaluation test of the ligament graft 14 closer to the body fluid environment inside the human body.

[0081] In a more specific embodiment, the first fastener 3 and the second fastener 6 are made of hard, corrosion-resistant materials.

[0082] In a more specific embodiment, the rigid anti-corrosion material is 316 stainless steel, which has better mechanical properties and excellent corrosion resistance, to meet the mechanical performance requirements of the main load-bearing components.

[0083] In a more specific embodiment, the first connector 1, the second connector 4, the femoral prosthesis 2, and the tibial prosthesis 5 are all made of lightweight, corrosion-resistant materials.

[0084] In a more specific embodiment, the lightweight corrosion-resistant material is polytetrafluoroethylene (PTFE), which has a low density and excellent corrosion resistance, meeting the weight requirements of the device and possessing corrosion resistance.

[0085] This invention provides an auxiliary testing device for the mechanical properties of ligament grafts, including parameter settings for femoral flexion, anterior-posterior displacement, and tibial rotation. Figures 7 to 8 As shown:

[0086] like Figure 7 The image shows the parameter settings for simulating femoral flexion movement. Femoral flexion degree of freedom refers to the relative angular movement of the tibial component of the femur around the flexion / extension axis in an artificial knee joint prosthesis, i.e., flexion / extension movement. Figure 7 The data represents the gait data corresponding to the femoral flexion gait movement. The horizontal axis X represents the percentage (%) of one cycle, and the vertical axis Y represents the femoral flexion angle (°).

[0087] like Figure 8 The image shows the parameter settings for simulating the anterior-posterior displacement motion of the tibia. The anterior-posterior displacement degree of freedom refers to the anterior-posterior displacement motion of the tibial component in the artificial knee joint prosthesis along a direction perpendicular to the tibial axis and the flexion / extension axis, and passing through the vertical load axis. Figure 8 The data represents the gait data corresponding to forward and backward displacement gait movements. The horizontal axis X indicates the percentage (%) of a cycle, and the vertical axis Y represents the forward and backward displacement (mm).

[0088] like Figure 9 The image shows the parameter settings for simulating tibial rotation. Tibial rotation is the angle of rotation of the tibia relative to an axis parallel to the tibial axis. Figure 9 The data represents the gait data corresponding to the tibial rotation gait movement. The horizontal axis X represents the percentage (%) of one cycle, and the vertical axis Y represents the tibial rotation angle (°).

[0089] It should be noted that when the knee joint bionic test platform operates according to the above-mentioned parameters, it can drive the femoral bionic component and the tibial bionic component to achieve the corresponding trajectory, thereby simulating the movement of the ligament graft 14 inside the human knee joint and improving the accuracy of the mechanical performance evaluation and life prediction results of the ligament graft 14.

[0090] In summary, the auxiliary testing device for the mechanical properties of ligament grafts provided by this invention can adjust the fixation positions of the tibial and femoral ends of different ligament grafts 14 according to experimental requirements, achieving different fixation angles for the ligament grafts 14. It can also be used for ligament graft mechanical property evaluation tests on a knee joint biomimetic testing platform, thereby improving the accuracy of mechanical property evaluation and lifespan prediction results. Simultaneously, it can simulate ligament grafts in different working states to obtain the mechanical properties of the ligament grafts 14 under different experimental conditions. Furthermore, the device is primarily constructed from materials with excellent corrosion resistance, such as polytetrafluoroethylene (PTFE) and 316 stainless steel, allowing it to better withstand the corrosive effects of the simulated body fluid environment during testing. This makes the simulation of the human body fluid environment in the ligament graft mechanical property evaluation test closer to the actual body fluid environment. Moreover, because it can perform mechanical property evaluation tests on different ligament grafts using a knee joint biomimetic testing platform, the degree of biomimicry in the tests is high, resulting in more accurate ligament graft mechanical property evaluation and lifespan analysis results.

[0091] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An auxiliary testing device for the mechanical properties of ligament grafts, characterized in that, include: A femoral bionic component and a tibial bionic component located below the femoral bionic component; The femoral bionic component includes a first connector, a femoral prosthesis, and a first fixation member; a first end of the first connector is used to connect with a femoral actuator, and a second end of the first connector is connected with the femoral prosthesis and the first fixation member; the first fixation member is located on one side of the femoral prosthesis and is used to press one end of a ligament graft onto the ligament attachment side of the femoral prosthesis. The tibial bionic component includes a second connector, a tibial prosthesis, and a second fixation member; the first end of the second connector is used to connect with a tibial actuator; the tibial prosthesis includes a plateau portion and a unicompartment of the tibial bone, and the second end of the second connector is connected to the plateau portion; the unicompartment of the tibial bone is disposed on the surface of the plateau portion, and a groove is formed on the surface of the plateau portion, the groove being located on one side of the unicompartment of the tibial bone; A second fixing member is provided in the groove, which is used to press the other end of the ligament graft against the side wall of the groove; the unicompartment of the tibia abuts against the end of the femoral prosthesis away from the first connector.

2. The auxiliary testing device for the mechanical properties of ligament grafts according to claim 1, characterized in that, Both the first and second fixing members include a threaded hole and a threaded fastener. The threaded fastener passes through the threaded hole and is threadedly engaged with it. The end of the threaded fastener is used to press and fix the ligament graft when the threaded fastener is inserted into the threaded hole and rotated so that the threaded fastener moves along the axial direction of the threaded hole toward the side of the femoral prosthesis ligament attachment or the side wall of the tibial prosthesis groove.

3. The auxiliary testing device for the mechanical properties of ligament grafts according to claim 2, characterized in that, The first and second fixing components further include a slide rail, a slider, and a locking component. The threaded hole and threaded fastener are disposed on the slider. The slider is slidably connected to the slide rail for adjusting the fixing position of the ligament graft on the ligament attachment side of the femoral prosthesis or the side wall of the tibial prosthesis groove. The locking component is connected to the slider and the slide rail respectively for fixing the slider on the slide rail.

4. The auxiliary testing device for the mechanical properties of ligament grafts according to claim 3, characterized in that, The locking component includes an auxiliary block, at least one limiting component, and at least one clamping component. The auxiliary block is provided with at least one first through hole, and the slider is provided with a second through hole corresponding to the first through hole. The slider is located on one side of the slide rail, and the auxiliary block is located on the other side of the slide rail. The limiting component is used to pass through the first through hole and the second through hole and then cooperate with the clamping component to fix the auxiliary block and the slider on the slide rail.

5. An auxiliary testing device for the mechanical properties of ligament grafts according to claim 3 or 4, characterized in that, Both the first and second fixators are disposed on the ligament attachment side near the femoral prosthesis. The sliding path of the first fixator is parallel to the axis of the femoral prosthesis, and is used to adjust the angle between the ligament graft and the ligament attachment side of the femoral prosthesis when the slider of the first fixator slides along the sliding path of the first fixator. The sliding path of the second fixator is parallel to the direction of the shortest line connecting the femoral prosthesis and the first fixator, and is used to adjust the angle between the ligament graft and the plateau surface when the slider of the second fixator slides along the sliding path of the second fixator.

6. The auxiliary testing device for the mechanical properties of ligament grafts according to claim 5, characterized in that, The femoral prosthesis has a unicompartment of the femur at one end away from the first connector. The surface of the unicompartment of the femur that abuts against the unicompartment of the tibia is a convex curved surface, and the surface of the unicompartment of the tibia that abuts against the unicompartment of the femur is a concave curved surface that abuts against the convex curved surface. This is to help the unicompartment of the femur to have its flexion axis collinear with the motor output shaft of the femoral actuator when it performs flexion movements. The femoral prosthesis is located on the central symmetry line of the first connector, and the projection line of the unicompartmental flexion axis of the femur on the first connector coincides with the central symmetry line; The projection surface of the first connector onto the second connector coincides with the second connector; The groove of the tibial prosthesis is divided by the slide into a fixation area for fixing the ligament graft and an operation area for manipulating the threaded fastener and the limiting member. The fixation area is located in the middle of the second connector, and the operation area is located near the edge of the second connector.

7. The auxiliary testing device for the mechanical properties of ligament grafts according to claim 6, characterized in that, It also includes a sleeve and a fastening member. The sides of the first connector and the second connector are provided with annular grooves. The sleeve is sleeved on the outside of the first connector and the second connector. The fastening member is used to press the sleeve into the annular groove so that the sleeve, the first connector and the second connector form a sealed space for filling with lubricant.

8. The auxiliary testing device for the mechanical properties of ligament grafts according to claim 7, characterized in that, The first connector, the second connector, the first fixation member, the second fixation member, the femoral prosthesis, and the tibial prosthesis are all made of anti-corrosion materials.

9. The auxiliary testing device for the mechanical properties of ligament grafts according to claim 8, characterized in that, Both the first and second fasteners are made of hard, corrosion-resistant materials.

10. An auxiliary testing device for the mechanical properties of ligament grafts according to claim 9, characterized in that, The first connector, the second connector, the femoral prosthesis, and the tibial prosthesis are all made of lightweight, corrosion-resistant materials.

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