Joint tension measuring device

Abstract

The present application discloses a joint tension measuring device, which is used to spread a first bone and a second bone to form a spread gap, and includes a spread component, a spread drive component, and an elastic potential energy component. The spread component is used to abut against the first bone and the second bone; the spread drive component is used to drive the spread component; the elastic potential energy component is arranged on the drive component, and the elastic potential energy component is used to receive and transmit external force to the spread drive component. When the elastic potential energy component receives the external force, it can deform or move a predetermined amount relative to the spread drive component. When the elastic potential energy component receives the external force, it deforms or moves a predetermined amount relative to the spread drive component. Through the predetermined amount of deformation or movement, the user is transmitted information about the size of the spread force on the first bone and the second bone or whether the spread force reaches a predetermined size.

Description

Technical Field

[0001] The present application relates to the field of medical devices, and in particular to a joint tension measuring device. Background Art

[0002] In total knee replacement surgery, good joint force alignment and soft tissue balance can ensure joint stability and achieve good flexion and extension function of patients after surgery. When clinically applied to knee surgery, doctors use a spreader to spread the distal femur and proximal tibia with a predetermined force, and obtain relevant parameters of the knee flexion and extension gap, such as gap value parameters or angle parameters that characterize the angle between the femur and tibia. The relevant parameters can assist doctors in evaluating the force alignment and soft tissue balance of the lower limbs, and ensure that these parameters are within the reference standard range under the predetermined force to obtain good lower limb force alignment and soft tissue balance.

[0003] At present, openers are generally divided into active and passive types. Among them, active openers measure the patient's joint gap and opening force (joint tension) through sensors and electrical signals. Although this can conveniently measure the opening force of the first bone and the second bone through sensors, it has high safety requirements and precision requirements for the sensor, which not only increases the cost of the opener but also increases the risk of electric shock to the patient; passive openers usually only have the opening function, or also have the function of measuring the gap and angle between the first bone and the second bone. Doctors can only rely on experience to open the first bone and the second bone with a certain amount of force, and cannot clearly know the state of the opening force on the joint. The state can be the current opening force size or whether the opening force reaches a certain predetermined size. In addition, different opening forces will correspond to different reference standards. Therefore, when the opening force size cannot be determined, it is impossible to effectively evaluate the relevant parameters, and it is impossible to ensure the normal joint force line and good soft tissue balance. Summary of the invention

[0004] Based on the above problems and defects, the present application provides a joint tension measurement device to facilitate doctors to open patients' joints.

[0005] The present application proposes a joint tension measuring device, which is used to spread a first bone and a second bone to form a spread gap, and includes a spread component, a spread drive component and an elastic potential energy component. The spread component is used to abut against the first bone and the second bone; the spread drive component is used to drive the spread component; the elastic potential energy component is arranged on the spread drive component, and the elastic potential energy component is used to receive and transmit external force to the spread drive component. When the elastic potential energy component receives the external force, it can undergo a predetermined amount of deformation or movement relative to the spread drive component.

[0006] In a first possible implementation, the elastic potential energy assembly includes an elastic member and a force-bearing member, the elastic member is disposed between the force-bearing member and the expansion drive assembly, and the force-bearing member is used to receive external force.

[0007] In combination with the above possible implementation manner, in a second possible implementation manner, the force-bearing member is hinged to the expansion drive assembly.

[0008] In combination with the above possible implementation methods, in a third possible implementation method, it also includes a stroke indicating mechanism arranged between the elastic potential energy component and the expansion drive component, and at least part of the structure of the stroke indicating mechanism can be displaced relative to the elastic potential energy component or the expansion drive component as deformation or movement occurs.

[0009] In combination with the above possible implementation modes, in a fourth possible implementation mode, the travel indicating mechanism includes a scale portion and a pointer portion, and the occurrence of deformation or movement causes relative displacement of the scale portion and the pointer portion.

[0010] In combination with the above possible implementation modes, in a fifth possible implementation mode, the scale portion is disposed on the expansion drive assembly, and the pointer portion is a sliding block that can slide along the scale portion.

[0011] In combination with the above possible implementation modes, in a sixth possible implementation mode, the expansion drive assembly includes a first handle and a second handle hingedly connected to each other, the scale portion is arranged on the first handle, the slider is slidably arranged on the first handle, and the slider is also connected to the elastic potential energy assembly to be driven by the elastic potential energy assembly.

[0012] In combination with the above possible implementation modes, in a seventh possible implementation mode, the scale portion is a scale rod, which is arranged at one of the expansion drive assembly and the elastic potential energy assembly, and the portion of the other of the expansion drive assembly and the elastic potential energy assembly adjacent to the scale rod forms a pointer portion.

[0013] In combination with the above possible implementation methods, in an eighth possible implementation method, the elastic potential energy component includes a force-bearing member and an elastic member, the force-bearing member is movably connected to the expansion drive assembly, the scale rod is fixed to the expansion drive assembly and cross-arranged with the force-bearing member, and the part adjacent to the force-bearing member and the scale rod forms a pointer part.

[0014] In combination with the above possible implementation modes, in a ninth possible implementation mode, the expansion drive assembly includes a first handle and a second handle hinged to each other, and a reset member is arranged between the first handle and the second handle, and the reset member is used to reset the expansion drive assembly, and the reset member is a spring or a reed.

[0015] In combination with the above possible implementation modes, in a tenth possible implementation mode, a switch component is provided between the elastic potential energy component and the expansion drive component, and the switch component is used to determine whether the elastic potential energy component undergoes a predetermined amount of deformation or movement relative to the expansion drive component when receiving external force.

[0016] In combination with the above possible implementation modes, in an eleventh possible implementation mode, the switch element is a switching paddle, and when the switching paddle is actuated, the elastic potential energy component and the expansion drive component form a rigid connection.

[0017] In combination with the possible implementation modes described above, in a twelfth possible implementation manner, the distraction drive assembly is provided with a distraction retaining member, and the distraction retaining member is used to maintain the distraction state of the first bone and the second bone when the distraction drive assembly is not subjected to external force.

[0018] In combination with the above possible implementation modes, in a thirteenth possible implementation manner, the expansion retaining member includes a rack and a movable limit block, and the movable limit block maintains the expansion state when it abuts against the rack.

[0019] In combination with the above possible implementation modes, in a fourteenth possible implementation mode, the expansion assembly includes a first expansion plate and a second expansion plate, and the joint tension measuring device also includes a gap conversion mechanism, the gap conversion mechanism includes a movable part, and the movable part is driven by the first expansion plate to amplify and / or convert the moving motion of the first expansion plate relative to the second expansion plate into a rotational motion.

[0020] In combination with the above possible implementation modes, in a fifteenth possible implementation mode, the gap conversion mechanism further includes a guide member, and the first spreading plate drives the movable member to move and rotate along the guide member.

[0021] In combination with the above possible implementation modes, in a sixteenth possible implementation mode, when the movable member rotates, a circumferential rotation distance of a predetermined position on the movable member is greater than a movement distance of the movable member along the guide member.

[0022] In combination with the above possible implementation modes, in a seventeenth possible implementation mode, the guide member and the movable member are non-self-locking screw nut structures.

[0023] In combination with the above possible implementation modes, in an eighteenth possible implementation mode, the guide member is a guide column, a spiral guide groove is arranged on the guide column, the movable member is a scale wheel, the inner ring of the scale wheel is provided with a guide portion, and the guide portion can slide along the guide groove.

[0024] In combination with the possible implementation modes described above, in a nineteenth possible implementation mode, the guide portion is a hemispherical protrusion or a ball.

[0025] In combination with the above possible implementation modes, in a twentieth possible implementation mode, a guide block is provided between the scale wheel and the first support plate, and the first support plate drives the guide block to move along the guide column to cause the scale wheel to move along the guide column.

[0026] In combination with the above possible implementation modes, in a twenty-first possible implementation mode, a notch is provided in the guide block, and the scale wheel is at the same height as the notch and is embedded in the notch.

[0027] In combination with the foregoing possible implementation modes, in a twenty-second possible implementation mode, the movable member and the guide member are a gear rack structure.

[0028] In combination with the above possible implementation modes, in a twenty-third possible implementation mode, the movable member includes a coaxial gear and a second scale wheel, the guide member is a rack, and the gear is meshed with the rack.

[0029] In combination with the foregoing possible implementations, in a twenty-fourth possible implementation manner, the radius of the second scale wheel is greater than the radius of the gear.

[0030] In combination with the above possible implementation methods, in the twenty-fifth possible implementation method, it also includes an angle conversion mechanism, the angle conversion mechanism includes an input end and an output end, the input end is driven by the first support plate, and the output end is used to amplify and / or convert the rotation of the first support plate along its own axis into circular motion or linear motion.

[0031] In combination with the foregoing possible implementation manners, in a twenty-sixth possible implementation manner, the angular velocity of the circular motion is greater than the angular velocity of the first support plate rotating along its own axis.

[0032] In combination with the above possible implementation modes, in a twenty-seventh possible implementation mode, the output end is provided with an indicator and an angle scale, and the indicator follows the output end to perform circular motion or linear motion relative to the angle scale to represent the rotation angle of the first support plate.

[0033] In combination with the above possible implementation modes, in a twenty-eighth possible implementation mode, the angle conversion mechanism is a speed increasing mechanism.

[0034] In combination with the above possible implementation methods, in a twenty-ninth possible implementation method, the reverse reducer structure includes an input shaft, a first gear, a second gear and an output shaft, the input shaft, the first support plate and the first gear rotate coaxially, the output shaft rotates coaxially with the second gear, and the first gear is meshed with the second gear.

[0035] In combination with the foregoing possible implementations, in a 30th possible implementation, the number of teeth of the second gear is less than the number of teeth of the first gear.

[0036] In combination with the above possible implementation modes, in a thirty-first possible implementation mode, the indicator is a pointer, and the angle scale is a dial; or, the indicator is a dial, and the angle scale is a scale circle with indicator marks.

[0037] In combination with the foregoing possible implementations, in a thirty-second possible implementation, the angle conversion mechanism is a gear rack structure.

[0038] In combination with the above possible implementation modes, in a thirty-third possible implementation mode, the rack and pinion structure includes a transmission shaft, a third gear and a rack, and the transmission shaft, the first support plate and the third gear rotate coaxially.

[0039] In combination with the above possible implementation modes, in a thirty-fourth possible implementation mode, the indicator is a rack, and the angle scale is a linear scale.

[0040] When the joint tension measuring device proposed in the present application is used, the elastic potential energy component transmits the external force applied by the user to the distraction driving component, and the distraction driving device drives the distraction component to distract the first bone and the second bone. When the elastic potential energy component receives the external force, it undergoes a predetermined amount of deformation or movement relative to the distraction driving component, and through the predetermined amount of deformation or movement, it transmits to the user the information of the magnitude of the distraction force on the first bone and the second bone or whether the distraction force reaches a predetermined magnitude. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a schematic diagram of the structure of the joint tension measurement device of the present application;

[0042] Figure 2 This is a schematic diagram of the elastic potential energy component structure of the present application;

[0043] Figure 3 This is a structural schematic diagram of another implementation of the elastic potential energy component of the present application;

[0044] Figure 4 This is a structural schematic diagram of another embodiment of the elastic potential energy component of the present application;

[0045] Figure 5 This is a schematic diagram of the structure of the gap conversion mechanism of the present application;

[0046] Figure 6 This is a schematic diagram of the structure of the movable parts of the gap conversion mechanism of the present application;

[0047] Figure 7 This is a structural schematic diagram of another implementation of the gap conversion mechanism of the present application;

[0048] Figure 8 This is a structural schematic diagram of another implementation mode of the gap conversion mechanism of the present application;

[0049] Fig. 9 This is a schematic diagram of the angle conversion mechanism structure of the present application;

[0050] Fig.10 This is a schematic diagram of the dial and scale ring structure of the present application;

[0051] Fig.11 A structural schematic diagram of another embodiment of the angle conversion mechanism of the present application;

[0052] Fig.12 This is a schematic diagram of the switch structure of the present application;

[0053] Fig.13 This is a schematic diagram of the structure of the support and retaining member of the present application;

[0054] Figure numerals: 1-first opening plate, 2-second opening plate, 3-first handle, 301-first active section, 302-first driven section, 4-second handle, 401-second active section, 402-second driven section, 5-elastic member, 6-force bearing member, 7-scale part, 8-pointer part, 801-connecting rod, 802-slider, 9-base, 10-guide column, 11-guide block, 111-notch, 12-hinge, 13-movable member, 131-second scale wheel, 1311-wheel body, 13 12-guide part, 132-gear, 14-guide member, 141-guide column, 1411-guide groove, 15-first shaft, 16-gear ring, 17-pinion, 18-second shaft, 19-pointer, 20-dial, 21-scale circle, 22-second gear, 23-second rack, 24-reset member, 25-switch member, 251-push wheel, 252-abutment part, 26-opening retaining member, 261-third rack, 262-movable limit block, 263-wrench, 264-limiting part. DETAILED DESCRIPTION

[0055] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by illustrating the examples of the present application.

[0056] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0057] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The embodiments will be described in detail below in conjunction with the accompanying drawings.

[0058] The present application proposes a joint tension measuring device, which is used to spread a first bone and a second bone to form a spread gap. The joint tension measuring device specifically includes a spread component, a spread drive component and an elastic potential energy component, wherein the spread component is used to abut against the first bone and the second bone; the spread drive component is used to drive the spread component; the elastic potential energy component is arranged on the drive component, and the elastic potential energy component is used to receive and transmit external force to the spread drive component. When the elastic potential energy component receives the external force, it can undergo a predetermined amount of deformation or movement relative to the spread drive component.

[0059] When using the joint tension measuring device, the external force applied by the user is transmitted to the distraction drive component through the elastic potential energy component. The distraction drive component receives the external force and drives the distraction component to distract the first bone and the second bone abutting against it to form a distraction gap. In the process of the elastic potential energy component receiving and transmitting the external force, the elastic potential energy component undergoes a predetermined amount of deformation or movement relative to the distraction drive component. The deformation or movement is caused by the external force received and transmitted by it. The size of the external force directly affects the size of the deformation or movement. According to the properties of the elastic potential energy component itself regarding deformation or movement, the size of the external force and the degree of deformation or movement have a definite conversion relationship. Therefore, the predetermined amount of deformation or movement of the elastic potential energy component can characterize the size of the distraction force or whether the distraction force has reached a certain predetermined size.

[0060] Furthermore, when a normal joint formed by the first bone and the second bone is expanded with different expansion forces, the gap between the first bone and the second bone will be different, so different expansion forces correspond to different reference standards for evaluating the joint force line and the balance of soft tissue. In this way, the user can maintain an appropriate or predetermined expansion force to expand the first bone and the second bone by controlling the deformation or movement amplitude of the elastic potential energy component, and can effectively evaluate the joint force line and the balance of joint soft tissue with a certain reference standard.

[0061] The following takes the joint tension measurement device for opening the knee joint as an example and describes the embodiment in detail with reference to the accompanying drawings.

[0062] refer to Figure 1 and Figure 2 The joint tension measuring device includes a distraction component, a distraction driving component and an elastic potential energy component.

[0063] The expansion assembly includes a first expansion plate 1 and a second expansion plate 2, the lower surface of the first expansion plate 1 is opposite to the upper surface of the second expansion plate 2, the upper surface of the first expansion plate 1 is used to abut against the distal end of the femur, and the lower surface of the second expansion plate 2 is used to abut against the proximal end of the tibia. The shapes of the first expansion plate 1 and the second expansion plate 2 are both "concave" shapes and the corners are rounded. The expansion drive assembly has a first handle 3 and a second handle 4 that are hinged to each other. With the hinge as the boundary, the first handle 3 is divided into a first active section 301 and a first driven section 302, and the second handle 4 is divided into a second active section 401 and a second driven section 402. The length of the first active section 301 is greater than the length of the first driven section 302, and the length of the second active section 401 is greater than the length of the second driven section 402. The first active section 301 is a rod with a rectangular cross section. The elastic potential energy assembly includes an elastic member 5 and a force-bearing member 6. The force-bearing member 6 is a movable handle hinged to the first active section 301. The elastic member 5 is a spring, one end of which is fixed to the first active section 301, and the other end is fixed to the movable handle. In addition, the force-bearing member 6 may not be hinged to the first active section, but may be connected to the first active section through the elastic member 5.

[0064] A travel indicating mechanism is arranged between the force-bearing member 6 and the first active section 301. The travel indicating mechanism includes a scale portion 7 and a pointer portion 8. The scale portion 7 is arranged on the first active section 301 and includes one or more scale lines and numerical values ​​corresponding to the scale lines. The scale lines and numerical values ​​are arranged on the surface of the first active section 301 close to the force-bearing member 6. Of course, the scale lines can also be arranged on two side surfaces. The pointer portion 8 includes a connecting rod 801 and a slider 802. One end of the connecting rod 801 is hinged to the movable handle, and the other end is hinged to the slider 802. The slider is provided with a groove-shaped or hole-shaped matching portion. The cross-sectional shape of the matching portion matches the cross-sectional shape of the first active section 301. The slider 802 is fitted on the first active section 301 through the matching portion and can slide along the first active section 301.

[0065] In addition, a base 9 extends from the axis of the second spreader plate 2, and two guide columns 10 are arranged on the base 9 and are perpendicular to the second spreader plate 2, that is, the direction of the guide columns 10 is the same as the direction in which the femur and tibia are about to be separated. A guide block 11 is sleeved on the guide column 10, and the first spreader plate 1 is matched with the axial hole of the guide block 2. The first driven section 301 is connected to the guide block 11 and drives the guide block 11 to move along the guide column 10, and the movement of the guide block 11 makes the first spreader plate 1 move away from the second spreader plate 2.

[0066] When using the joint tension measuring device, the distraction assembly is inserted between the femur and the tibia and the first distraction plate 1 is brought into contact with the distal end of the femur and the second distraction plate 2 is brought into contact with the proximal end of the tibia. The user grasps the movable handle and the second active section 401 and applies a gripping force thereto. The movable handle compresses the spring and gradually approaches the first active section 301. The connecting rod 801 rotates relative to the movable handle and pushes the slider 802 to slide along the first active section 301. The spring applies an external force to the first active section 301 to drive the first handle 3 and the second handle 4 to move. Under the action of the external force, the first active section 301 moves toward the second active section 401, and the first driven section 302 moves away from the second driven section 402. The first driven section 301 pushes the guide block 11 to slide along the guide column 10. The sliding of the guide block 11 drives the first distraction plate 1 away from the second distraction plate 2. The femur and the tibia are distracted by the distraction force to form a distraction gap. In addition, the user can know the magnitude of the distraction force through the scale line and value aligned with the slider 802.

[0067] A specific force analysis is conducted on this. With the coordinate system where the second handle 4 is located as a reference, the second active section 401 and the second driven section 402 are fixed to the coordinate system. The action of the joint tension measuring device can be regarded as the first active section 301 under the action of the external force F, with the hinge 12 of the first handle 3 and the second handle 4 as a fulcrum, through the transmission between the first driven section 301, the guide block 11 and the first expansion plate 1, using the expansion force f to pry the femur away from the tibia. Among them, the first force arm of the external force F is the distance X1 between the spring on the first active section 301 and the hinge 12, and the second force arm of the expansion force f is the distance X2 between the characteristic point on the first expansion plate 1 and the hinge 12. The characteristic point is generally taken as the center of the first expansion plate 1. Of course, the force contact point between the first expansion plate 1 and the femur can also be selected according to the actual situation. When the femur and tibia are stably expanded, F*X1=f*X2.

[0068] It is easy to understand that the compression force Y on the spring is equal to the external force F transmitted to the first active section 301 by the spring. Therefore, combined with the above equation, the distraction force f on the femur and tibia has a linear relationship with the pressure on the spring, that is, f = (X1 / X2)*Y. The compression force Y on the spring also has a linear relationship with the compression amount x of the spring, Y = kx, where k is the elastic coefficient of the spring. Therefore, the distraction force f has a linear relationship with the compression amount x of the spring, that is, f = (X1 / X2)*kx. In short, the compression amount x of the spring can be directly used as the characterization information of the distraction force f.

[0069] During the operation of the joint tension measuring device, the compression x of the spring is not easy to be identified and measured by the naked eye, and the magnitude of the opening force represented by the compression x of the spring alone is not easy for the user to know. The connecting rod 801 and the slider 802 as the pointer part 8 convert the compression x of the spring into the movement p of the slider 802 along the first active section 301. The compression x of the spring corresponds to the movement p of the slider 802, x=wp, and w is the conversion coefficient. Therefore, it is derived that f=(X1 / X2)*kwp, that is, the movement p of the slider 802 has a corresponding relationship with the opening force f, and the movement p of the slider 802 can represent the opening force f. In this way, when the slider 802 produces a certain amount of movement, the scale line aligned with it has a one-to-one correspondence with the opening force f, and the user can read the scale line and the value aligned with the slider 802 to know the magnitude of the opening force f, wherein the value can be a value reflecting the actual size of the opening f, or a value for dividing the magnitude of the opening force f.

[0070] like Figure 3 As shown, in an optional embodiment, the scale portion 7a is configured as a scale rod for measuring the compression of the spring, and the scale rod is marked with scale lines and values ​​representing the expansion force. The scale rod is arranged in the spring as the elastic member 5, and one end of the scale rod is fixedly connected to the first active section 301, and the other end passes through the movable handle and can move relative to the movable handle; the pointer portion 8a is the movable handle or a part of the movable handle close to the scale rod.

[0071] In this way, when the user grasps the movable handle and the second active section 402 to make the first expansion plate 1 and the second expansion plate 2 expand the femur and the tibia, the spring is compressed, and the movable handle moves a certain distance q relative to the scale rod, and the distance q is the compression amount x of the spring. The same principle as the above embodiment, f = (X1 / X2) * kq is derived from f = (X1 / X2) * kx, and the moving distance q of the movable handle can characterize the expansion force f. When the movable handle moves relative to the scale rod, the scale line and the value aligned with it have a one-to-one correspondence with the expansion force f, and the user can read the scale line and the value aligned with the pointer part 8a on the scale rod to know the size of the expansion force f.

[0072] Of course, the scale rod can be set not in the spring but at other positions between the movable handle and the first active section 301. In this way, the moving distance q of the movable handle relative to the scale rod and the compression amount x of the spring have a certain conversion relationship x=mq, so f=(X1 / X2)*kmq, and the magnitude of the expansion force f can still be represented by the change of the scale on the scale rod. Only the corresponding relationship between the numerical value corresponding to the scale line and the expansion force f has changed.

[0073] like Figure 4As shown, in an optional embodiment, the scale portion 7b is configured as an angle dial for measuring the rotation range of the movable handle relative to the first handle 3, one end of the angle dial is fixedly connected to the first active section 301, and the angle dial is marked with scale lines and values ​​representing the expanding force; the pointer portion 8a is a partial structure on the movable handle that is close to or overlaps with the angle dial.

[0074] When the user grasps the movable handle and the second active section 401 to make the first expansion plate 1 and the second expansion plate 2 expand the femur and the tibia, the spring is compressed, and the movable handle rotates a certain angle a relative to the first active section 301. The compression amount x of the spring has a certain conversion relationship x=ia with the angle a, so f(X1 / X2)*kia, and the magnitude of the expansion force f can be characterized by the scale lines and numerical changes on the angle dial. When the movable handle rotates relative to the first active section 301, the scale lines aligned with the angle dial have a one-to-one correspondence with the expansion force f, and the user can read the scale lines and numerical values ​​on the angle dial aligned with the pointer part 8 to know the magnitude of the expansion force f.

[0075] based on Figure 1-4 In the embodiment shown, in an optional implementation, the travel indicating mechanism may not be provided, and the state of the opening force may be represented only by the deformation of the spring or the movement of the movable handle relative to the first handle 3. In this way, when the user grasps the movable handle 401 to make the first opening plate 1 and the second opening plate 2 open the femur and the tibia, the spring is compressed. When the spring is fully compressed, the compression amount of the spring is a fixed value d, and the fixed value d is known because it is related to the spring itself. According to f = (X1 / X2) * kd, it can be known that the spring has a certain opening force f when it is fully compressed. In other words, through such a setting, the user can know whether the opening force reaches a certain size by observing whether the spring is fully compressed, and the size of the opening force is known. Of course, the size of the opening force represented by the spring when it is fully compressed can be changed by changing the model of the spring; the size of the opening force represented by the spring when it is fully compressed can also be changed by setting different pre-compression amounts for the spring.

[0076] Alternatively, by not setting a stroke indicating mechanism, the state of the opening force can be represented by only the movement of the movable handle relative to the second handle 4. By setting the elastic potential energy component, the user can judge whether the opening force has reached a predetermined magnitude by observing whether the movement of the movable handle relative to the second handle 4 has reached a predetermined magnitude. There is a large stroke variation space between the movable handle and the second handle 4. When the opening force changes slightly, the movable handle will move more relative to the second handle, and the larger movement is easier to be observed by the user, and it is convenient for the user to further judge whether the movement of the movable handle relative to the second handle 4 has reached a predetermined magnitude.

[0077] In an optional embodiment, if Figure 1 and Figure 5-6 As shown, the joint tension measuring device is also provided with a gap conversion mechanism, which includes a movable part 13 and a guide part 14. The movable part 13 is a scale wheel with scales marked on the circumference, and the scale wheel includes a wheel body 1311 and a guide part 1312 arranged on the inner ring of the wheel body 1311, and the guide part 1312 is a hemispherical protrusion; the guide part 14 is a guide column 10 with a spiral guide groove 1411, and the cross section of the guide groove 1411 is a semicircle with the same radius as the half-surface protrusion, and the thread lead angle of the guide groove 1411 is greater than the equivalent friction angle between the guide groove 1411 and the hemispherical protrusion. Figure 1 On the basis of the embodiment shown, a guide groove 1411 is provided on one of the two guide posts 11 as the guide member 14, and a notch 111 is provided on the side of the guide block 11, and the guide post with the guide groove 1411 passes through the notch 111, and the height of the notch 111 is equal to the height of the wheel body 1311. The movable member 13 is embedded in the notch 111 and sleeved on the guide member 14, and the guide portion 1312 is located in the guide groove 1411, and the movable member 13 and the guide member 14 form a non-self-locking screw nut pair.

[0078] Furthermore, the pitch of the guide groove 1411 is set to the maximum distance that the first expansion plate 1 and the second expansion plate 2 can expand, and the circumference of the outer periphery of the movable member 13 is 3 times the pitch of the guide groove 1411. When the first expansion plate 1 and the second expansion plate 2 reach the maximum expansion degree, the movable member 13 moves axially by a pitch and rotates circumferentially for one circle.

[0079] In this way, when the first expansion plate 1 is driven by the first handle 3 to move relative to the second expansion plate 2, the guide block 11 slides along the guide column 10 and keeps synchronization with the movement of the first expansion plate 1. The guide portion 1312 causes the movable member 13 to rotate circumferentially under the guidance of the guide groove 1411. The circumferential length corresponding to the angle of the circumferential rotation of the movable member 13 is 3 times the axial movement distance of the movable member 13. In other words, the actual distance between the two scale lines on the movable member 13 representing the 1mm expansion distance is 3mm. Since the knee joint gap itself is small, if the relative movement distance of the first expansion plate 1 and the second expansion plate 2 is directly displayed as the actual distance, the millimeter-level scale lines used to display the knee joint gap distance will be relatively dense, which makes it difficult for users to observe and easy to read wrong when reading. However, by using the graduated wheel as the movable part 13 and the guide column provided with the guide groove 1411 as the guide part 14, the gap distance between the first bone and the second bone is magnified and displayed as the circumferential distance of the rotation of the graduated wheel. The scale lines displayed on the graduated wheel are sparser, the scale changes are more obvious, and the gap distance is easier for the user to identify and read.

[0080] Of course, the circumference of the outer periphery of the movable part 13 is not limited to 3 times of the pitch, and can also be 4 times, 5 times, etc., so as to clearly display the gap value and be easily recognized by the user. However, the circumference of the outer periphery of the movable part 13 should not be too long, so as to avoid the movable part 13 being too large and interfering with the use of the joint tension measurement device.

[0081] In an optional embodiment, if Figure 7 As shown, the movable member 13a is a coaxial gear 132 and a second scale wheel 131, the radius of the gear 132 is smaller than the radius of the second scale wheel 131, and the second scale wheel 131 is marked with scales; the guide member 14a is a rack and meshes with the gear 132, the guide member 14a is fixed to the axis of the second spread plate 2 and is perpendicular to the second spread plate 2, and the gear 132 is connected to the first spread plate 1 through a gear shaft. When the first spread plate 1 moves relative to the second spread plate 2, the gear shaft moves relative to the second spread plate 2, and the gear 132 moves along the rack under the action of the rack and rotates circumferentially, and the second scale wheel 131 and the gear 132 produce circumferential rotation at the same angle.

[0082] It can be understood that the distance that the first expansion plate 1 moves relative to the second expansion plate 2 is the distance that the gear shaft moves relative to the rack. The gear shaft drives the gear 132 to move along the rack, and the distance moved is equal to the first arc length distance corresponding to the angle of the circumferential rotation of the gear 132. In this way, the first arc length distance of the circumferential rotation of the gear 132 is equal to the distance that the first expansion plate 1 moves relative to the second expansion plate 2, and the first arc length distance is the distance of the expansion gap between the femur and the tibia. Corresponding to the first arc length distance, the second scale wheel 131 rotates coaxially with the gear and rotates circumferentially by the second arc length distance. Since the radius of the second scale wheel 131 is greater than the radius of the gear 142, the second arc length distance is greater than the first arc length distance and the two have a fixed multiple relationship, wherein the multiple relationship is the multiple relationship of the radius of the second scale wheel 131 relative to the radius of the gear 132, and the second arc length distance can be used to characterize the distance of the expansion gap. When the gap distance is read directly without conversion, the gap itself is small and the marked scale lines are dense, which makes it difficult for the user to observe and easy to read incorrectly when reading. However, through the arrangement of the rack, gear 132 and the second scale wheel 131, the gap distance is magnified and displayed. The scale lines of the scale corresponding to the second arc length distance rotated by the second scale wheel 131 are more spaced apart and the changes in the scale lines during rotation are more obvious. The user can more clearly identify the expansion distance through the scale on the second scale wheel 131.

[0083] Of course, the rack can also be fixed to the first opening plate 1, and the gear shaft can be fixed to the second opening plate. The principle is the same as that in the above embodiment, so it will not be repeated.

[0084] In an optional embodiment, if Figure 8As shown, the movable part 13b is a lever, which is hinged to the second opening plate 2. The lever includes a first section and a second section with the hinge as the boundary; the guide part 14b is a distance scale arranged at the second section, and the distance scale is parallel to the direction of movement of the first opening plate 1. The first opening plate 1 is provided with a connecting end in contact / connection with the first section. When the first opening plate 1 and the second opening plate 2 are in contact, the lever is in a position parallel to the second opening plate, and the point in contact / connection with the connecting end on the first section is the initial point z. The distance l1 between the initial point z and the hinge is smaller than the distance l2 between the distance scale and the hinge. When the first opening plate 1 moves relative to the second opening plate 2, the first opening plate 1 pulls (or pushes) the first section to rotate relative to the hinge, and the second section moves relative to the distance scale during the rotation.

[0085] A motion analysis is conducted on this. When the first opening plate 1 and the second opening plate 2 are fitted together, the lever is in the initial state parallel to the second opening plate 2, and the opening gap is zero. When the first opening plate 1 moves relative to the second opening plate 2, a straight line is drawn through the initial point z in the moving direction of the first opening plate 1. The distance between the intersection g of the straight line and the first segment and the initial point z is the distance L1 that the first opening plate 1 moves relative to the second opening plate 2, that is, the opening gap L1. The position change distance L2 indicated by the second end on the distance scale has a fixed multiple relationship with the opening gap, which is a multiple relationship of l2 and l1. It can be understood that when the gap distance is read directly without conversion, the gap itself is small and the marked scale lines are dense, which makes it difficult for the user to observe and easy to read incorrectly. However, through the setting of the lever and the distance scale, the gap distance is magnified and displayed, and the position change distance L2 indicated by the second end on the distance scale is converted into the magnified gap. The absolute size of the position change distance L2 is larger and the scale lines are sparse, making it easier for the user to identify and read the gap distance.

[0086] In an optional embodiment, if Figure 5 and Fig. 9 As shown, the joint tension measuring device is provided with an angle conversion mechanism, which measures the valgus / valgus angle of the joint force line between the femur and the tibia by measuring the rotation angle of the first spreader plate 1 and displays it in an amplified manner. The angle conversion mechanism includes a first shaft 15, a gear ring 16, a pinion 17, a second shaft 18, a pointer 19 and a dial 20. The first shaft 15 extends from the axis of the first spreader plate 1; the gear ring 16 is circumferentially positioned with the first shaft 15 and the gear teeth are arranged on the inner circumference of the gear ring 16; the second shaft 18 can rotate relative to the dial 20, the pinion 17 is fixedly sleeved on the second shaft 18 and internally meshed with the gear ring 16, and the radius of the trajectory profile where the gear teeth in the gear ring 16 are located is 20 times the radius of the pinion 17; the pointer 19 is fixed with the second shaft 18; and the dial 20 is provided with scale lines and scale values ​​indicating angles along the circumference of the second shaft 18.

[0087] When the first spreader plate 1 contacts the femur and the second spreader plate 2 contacts the tibia, the first spreader plate 1 is perpendicular to the femoral axis, and the second spreader plate 2 is perpendicular to the tibia axis. The angle between the femoral axis and the tibia axis causes the first spreader plate 1 to flip along its own axis, and the flip angle is the valgus / valgus angle of the knee joint force line. The flipping of the first spreader plate 1 is transmitted to the ring gear 16 through the first shaft 15. The ring gear 16 rotates at the same angle as the first spreader plate 1 with the first shaft 15 as the axis. The pinion 17 rotates under the action of the ring gear 16 and has the same linear speed as the ring gear 16. The pointer 19 keeps synchronous rotation with the pinion 17 through the second shaft 18. When the ring gear 16 rotates a certain angle, the angle rotated by the pinion 17, the second shaft 18 and the pointer 19 is 20 times the rotation angle of the ring gear 16; the pointer 19 is aligned with the corresponding scale line and scale value on the dial 20.

[0088] Thus, when the first spreader plate rotates 1 degree, the pointer 19 rotates 20 degrees after being magnified by the angle conversion mechanism, and the scale line and scale value corresponding to the 20 degrees of rotation of the pointer 19 represent the rotation of the first spreader plate 1 by 1 degree. The original small angle change is magnified by the angle conversion mechanism into a larger angle change of the pointer 19, which can more clearly display the valgus / valgus angle of the knee joint.

[0089] Of course, the radius of the trajectory profile of the gear teeth in the gear ring 16 is not limited to 20 times the radius of the pinion 17, and can also be 10 times, 15 times or other multiples, as long as the rotation angle of the second support plate 2 can be significantly magnified and clearly displayed.

[0090] based on Figure 1-9 In the embodiment shown, in an optional implementation, the ring gear 16 can be replaced by a large gear having a radius greater than the pinion 17, and the large gear is externally meshed with the pinion 17. In this way, the rotation angle of the first opening plate 1 is amplified by the transmission of the first shaft 15, the large gear, the pinion 17, the second shaft 18 and the pointer 19 in sequence, and the amplification factor is the multiple of the radius of the large gear relative to the pinion 17.

[0091] Based on the above embodiment, in an optional implementation manner, as Fig.10 As shown, the scale ring 20a is fixed to the second rotating shaft 18, and a scale ring 21 with an indication line is arranged around the scale ring 20a. In this way, when the first spreading plate rotates, the scale ring 20a rotates a certain angle with the second shaft 18 through the transmission of the first shaft 15, the gear ring 16, the pinion 17, and the second shaft 18, and the indication line on the scale ring 21 is aligned with a certain scale line and scale value on the scale ring 20a, and the knee joint valgus / valgus angle can be obtained by reading its value. Compared with the setting form of the pointer 19 and the scale ring 20, the outer periphery of the scale ring 21 and the scale ring 20a are both circular, and there is no sharp part like the pointer 19, which is not easy to hurt the user and the patient when used.

[0092] In an optional embodiment, if Fig.11 As shown, the angle conversion mechanism includes a first shaft 18, a second gear 22, a second rack 23, a rack guide, and a scale 24. The first shaft 18 extends from the axis of the first spreader plate 1; the second gear 22 is circumferentially positioned with the first shaft 18; the second rack 23 is meshed with the second gear 22, and the second rack 23 moves linearly relative to the scale 24 under the guidance of the gear guide. In this way, the rotation of the first spreader plate 1 is converted into linear motion through the transmission of the gear rack. The larger the radius of the second gear 22, the longer the linear motion distance of the second rack 23 when the first spreader plate 1 rotates a certain angle, and the more obvious the scale change of the second rack 23 on the scale is aligned. The rotation of the first spreader plate is magnified into the linear motion of the second rack 23, so that the knee joint valgus / valgus angle is easier to be read by the user.

[0093] In an optional embodiment, if Figure 1 As shown, a reset member 24 is provided between the first handle 3 and the second handle 4, and the reset member 24 is a spring or a reed. In this way, after the joint tension measuring device is used, the first handle 3 and the second handle 4 are automatically reset to the initial state of zero opening gap under the action of the reset member 24, which is convenient for next use.

[0094] In an optional embodiment, if Figure 2 and Fig.12 As shown, a switch member 25 is arranged between the force-bearing member 6 and the first handle 3. The force-bearing member 6 is a movable handle, and the switch member 25 is a conversion paddle. The conversion paddle includes a dial wheel 251 and abutment portion 252. The dial wheel 251 and the abutment portion 252 are integrally formed or fixedly connected. The dial wheel 251 is embedded in the movable handle near the hinge between the movable handle and the first handle 3 and is hinged to the movable handle. There is a certain rotation damping between the dial wheel 251 and the movable handle. The edge of the dial wheel 251 protrudes from the movable handle, and the abutment portion 252 is located between the movable handle and the first handle 3.

[0095] The abutting state between the abutting portion 252 and the first handle 3 can be switched by turning the conversion paddle. When the abutting portion 252 abuts the first handle 3, the elastic potential energy component is invalid, and the movable handle forms a rigid connection with the first handle 3 under the action of the gripping force. When the user grips the movable handle and the second handle 4, the movable handle directly transmits the gripping force to the first handle 3 through the abutting portion 252. When the abutting portion is separated from the first handle 3, the elastic potential energy component is effective, and its specific working principle has been described in detail above and will not be repeated here.

[0096] In an optional embodiment, if Figure 1 and Fig.13As shown, an expansion retaining member 26 is arranged between the first handle 3 and the second handle 4 of the expansion drive assembly, and the expansion retaining member 26 includes a third rack 261 and a movable stop block. The third rack 261 is arc-shaped and one end of it is fixed to the first handle 3, and the other end passes through the second handle 4 and can move relative to the second handle 4; the movable stop block includes a connecting portion 262 hinged to the second handle 4, a wrench 263 arranged on the connecting portion 262 for driving the movable stop block to rotate relative to the second handle 4, and a stop portion 264 for abutting against the third rack 261.

[0097] When the limiting part 264 is in contact with the third rack 261, the first handle 3 and the second handle 4 cannot move relative to each other, and the relative positions of the first expansion plate 1 and the second expansion plate 2 remain fixed; when the limiting part 264 is separated from the third rack 261, the first handle 3 and the second handle 4 can move relative to each other. In this way, when the user uses a certain gripping force to expand the femur and tibia by a certain distance, the wrench 263 can be turned to make the limiting part 264 in contact with the third rack 261, and the expansion state of the femur and tibia by the first expansion plate 1 and the second expansion plate 2 is maintained. The user no longer needs to continuously apply force to maintain the expansion state of the femur and tibia, which saves effort in operation and makes it easier to maintain the stable expansion state of the femur and tibia, so as to facilitate the acquisition of relevant parameters of the knee joint expansion gap in a stable state to evaluate the soft tissue balance and joint force line of the patient.

[0098] Although the present application has been described in detail above with general descriptions and specific implementation schemes, it is obvious to those skilled in the art that some modifications or improvements can be made to the present application. Therefore, these modifications or improvements made without departing from the spirit of the present application are within the scope of protection claimed in the present application.

Claims

1. A joint tension measuring device, used for distracting a first bone and a second bone to form a distraction gap, characterized in that: include: The distraction assembly comprises a first distraction plate and a second distraction plate, wherein the first distraction plate is used to abut against the first bone, and the second distraction plate is used to abut against the second bone; The gap conversion mechanism comprises a scale wheel and a guide column, wherein the scale wheel is driven by the first opening plate to amplify and convert the movement of the first opening plate relative to the second opening plate into a rotational movement, the guide column is provided with a spiral guide groove, and the inner ring of the scale wheel is provided with a guide part, and the guide part can slide along the guide groove; An expansion drive assembly, used to drive the expansion assembly, the expansion drive assembly comprising a first handle and a second handle hingedly connected to each other; An elastic potential energy component is disposed on the expansion drive component, and is used to receive and transmit external force to the expansion drive component. When the elastic potential energy component receives the external force, it can deform or move by a predetermined amount relative to the expansion drive component; A stroke indicating mechanism is arranged between the elastic potential energy component and the expansion driving component. At least part of the structure of the stroke indicating mechanism can be displaced relative to the elastic potential energy component or the expansion driving component as the deformation or movement occurs. The stroke indicating mechanism includes a scale portion and a pointer portion. The deformation or movement causes relative displacement of the scale portion and the pointer portion. The scale portion is arranged on the first handle. The pointer portion is a slider that can slide along the scale portion. The slider is slidably arranged on the first handle. The slider is also connected to the elastic potential energy component to be driven by the elastic potential energy component.

2. The joint tension measuring device according to claim 1, characterized in that: The elastic potential energy component includes an elastic member and a force-bearing member, the elastic member is arranged between the force-bearing member and the expansion drive component, and the force-bearing member is used to receive the external force.

3. The joint tension measuring device according to claim 2, characterized in that: The force bearing member is hinged to the expansion driving assembly.

4. The joint tension measuring device according to claim 1, characterized in that: The scale portion is a scale rod, which is disposed on one of the expansion drive assembly and the elastic potential energy assembly, and the pointer portion is formed at a portion of the other of the expansion drive assembly and the elastic potential energy assembly adjacent to the scale rod.

5. The joint tension measuring device according to claim 4, characterized in that: The elastic potential energy assembly includes a force-bearing member and an elastic member. The force-bearing member is movably connected to the expansion drive assembly. The scale rod is fixed to the expansion drive assembly and cross-arranged with the force-bearing member. The portion of the force-bearing member adjacent to the scale rod forms the pointer portion.

6. The joint tension measuring device according to claim 1, characterized in that: The expansion drive assembly includes a first handle and a second handle which are hinged to each other. A reset member is arranged between the first handle and the second handle. The reset member is used to reset the expansion drive assembly. The reset member is a spring or a leaf spring.

7. The joint tension measuring device according to claim 1, characterized in that: A switch component is provided between the elastic potential energy component and the expansion drive component, and the switch component is used to determine whether the elastic potential energy component undergoes a predetermined amount of deformation or movement relative to the expansion drive component when receiving the external force.

8. The joint tension measuring device according to claim 7, characterized in that: The switch member is a conversion paddle, which, when in action, causes the elastic potential energy component and the expansion drive component to form a rigid connection.

9. The joint tension measuring device according to claim 1, characterized in that: The distraction drive assembly is provided with a distraction retaining member, and the distraction retaining member is used to maintain the distraction state of the first bone and the second bone when the distraction drive assembly is not subjected to external force.

10. The joint tension measuring device according to claim 9, characterized in that: The expansion retaining member comprises a rack and a movable limiting block, and the movable limiting block maintains the expansion state when abutting against the rack.

11. The joint tension measuring device according to claim 1, characterized in that: It also includes an angle conversion mechanism, which includes an input end and an output end, the input end is driven by the first support plate, and the output end is used to amplify and / or convert the rotation of the first support plate along its own axis into circular motion or linear motion.

12. The joint tension measuring device according to claim 11, characterized in that: The output end is provided with an indicator and an angle scale, and the indicator follows the output end to perform circular motion or linear motion relative to the angle scale to indicate the rotation angle of the first spreading plate.

13. The joint tension measuring device according to claim 12, characterized in that: The angle conversion mechanism is a speed increasing mechanism.

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