Unicondylar knee joint tightness measuring device

Abstract

The invention discloses a unicompartmental knee joint tightness measuring device in the technical field of medical instruments. The unicompartmental knee joint tightness measuring device comprises a gasket, a through groove parallel to the gasket is formed in the gasket, a bending angle measuring assembly and a tightness measuring assembly are arranged at one end of the through groove, a curve recording assembly is arranged at the other end of the through groove, and a prosthesis positioning assembly is fixedly connected to the top wall of the gasket. The elastic pressure between the femoral condyle and the tibial plateau is reflected through the compression amount of the spring, the elastic pressure is expressed on the instrument panel in a mechanical mode to help a doctor to measure the dynamic elastic pressure at the full buckling angle, the operation efficiency is improved, and the postoperative hidden danger is reduced; and an external laser sensor is used for configuring a dip angle before osteotomy to position a prosthesis dip angle and an osteotomy line on the femoral condyle, so that a doctor can conveniently restore the original femoral condyle contour of a patient by installing a prosthesis after osteotomy, and more data support is provided for exploring the principle and technical improvement of unicompartmental knee arthroplasty.

Description

Technical Field

[0001] The invention belongs to the technical field of medical devices, and in particular is a device for measuring the tightness of a unicompartmental knee joint. Background Art

[0002] Unicompartmental knee replacement is an effective treatment for unicompartmental knee osteoarthritis. It is primarily used when the disease is limited to the medial or lateral tibiofemoral compartment, while the other compartments and ligaments remain intact. During this procedure, accurately measuring the tightness of the knee joint is crucial.

[0003] Currently, the tightness assessment of unicompartmental knee arthroplasty (UKA) mainly relies on mechanical spacer sets and the subjective experience of the surgeon. The traditional method requires inserting the spacer into the joint gap and judging the tightness by the resistance felt by hand, which has significant defects. The measurement results are highly dependent on the surgeon's experience and lack quantitative standards. Its accuracy is difficult to be effectively guaranteed because the experience and technical level of different doctors vary. This makes the measurement results inconsistent between different operators. The difference in the assessment of the same joint gap by different surgeons can reach 0.8mm (J Arthroplasty 2020; 35(6): 1532). An error of more than 0.5mm can lead to the prosthesis being too tight (causing joint stiffness or collision) or too loose (increasing the risk of dislocation) after surgery.

[0004] Secondly, existing measurement methods often require repeated testing of spacers of varying sizes to determine the optimal knee tightness for the patient in order to balance the flexion / extension gap. This process adds an average of over 12 minutes to the surgical procedure, increasing the patient's exposure to the operating table and the surgical risk. Furthermore, repeated testing can cause damage to surrounding tissues, hindering postoperative recovery.

[0005] In addition, existing measurement devices cannot cover dynamic assessment of the full flexion angle, as shown in the patent document with announcement number CN107242907B. The knee joint needs to flex and extend continuously from 0° to 135° during the gait cycle, of which the 30°-60° semi-flexion position accounts for more than 62% of the load-bearing (J Biomech 2019; 82:124), but traditional devices only measure two static points: 0° / 20° (extension position) and 90° (flexion position). The dynamic tightness of the full flexion angle is often overlooked due to technical limitations, resulting in abnormal knee joint movement after postoperative recovery.

[0006] In summary, it is necessary to propose a unicompartmental knee joint tightness measurement device that can measure the dynamic tightness and pressure at the full flexion angle, accurately read the tightness and pressure data and flexion angle data, and record them, so as to improve the quality of surgery and patient prognosis. Summary of the Invention

[0007] In order to solve the above problems, the purpose of the present invention is to provide a unicompartmental knee joint tightness measuring device, which reflects the tightness pressure between the femoral condyle and the tibial plateau through the compression of the spring, and mechanically displays the tightness pressure on the instrument panel to help doctors measure the dynamic tightness pressure of the full flexion angle, improve surgical efficiency, and reduce postoperative hidden dangers. The inclination angle is configured on the femoral condyle before osteotomy through an external laser sensor to locate the prosthesis inclination and osteotomy line, making it convenient for doctors to restore the patient's original femoral condyle contour by installing the prosthesis after osteotomy, and provide more data support for exploring the principles and technical improvements of unicompartmental knee replacement.

[0008] To achieve the above-mentioned object, the technical solution of the present invention is as follows: a unicompartmental knee joint tightness measuring device, comprising a gasket, a through slot parallel to the gasket being formed inside the gasket, a flexion angle measuring component and a tightness measuring component being provided at one end of the through slot, a curve recording component being provided at the other end of the through slot, and a prosthesis positioning component being fixedly connected to the top wall of the gasket;

[0009] A flexion angle measurement component is used to follow the movement of the spacer between the femoral condyle and the tibial plateau to measure the angle changes of the femur and tibia and display the corresponding angle data;

[0010] A tightness measurement component, used for measuring knee joint tightness data that changes with angle between the femoral condyle and the tibial plateau and displaying the knee joint tightness data;

[0011] Curve recording component, used to record the data curve of knee joint tightness changing with angle;

[0012] Prosthesis positioning component, used to locate the prosthesis outward inclination angle and osteotomy line position.

[0013] The basic scheme works as follows: The present invention uses the flexion angle measurement component and the tightness measurement component on the spacer to measure the angular changes of the femur and tibia, as well as the tightness of the knee joint, respectively, and intuitively displays the measurement results. Simultaneously, a curve recording component mechanically records the data curve of the knee joint tightness changing with angle. Furthermore, the prosthesis positioning component mechanically locates the prosthesis's outward inclination angle and the position of the osteotomy line. These components work together to achieve comprehensive measurement and recording of knee joint tightness and flexion angle.

[0014] The benefits of the basic solution are as follows: 1. Traditional methods rely on the doctor's feel and experience, resulting in subjective and easily affected by individual differences. This device uses mechanical transmission and a pointer scale to quantitatively display angle and tightness data, reducing human error, improving measurement objectivity and accuracy, and enabling consistent results across different doctors.

[0015] 2. The knee joint continuously flexes and extends during the gait cycle. Traditional devices can only measure static points such as flexion and extension, and cannot fully reflect changes in tightness. This device can measure tightness across the full flexion range of 0°-135°, providing doctors with comprehensive data to optimize prosthesis selection and installation, improve surgical outcomes, and reduce the risk of postoperative abnormalities.

[0016] 3. The curve recording component mechanically records the tightness curve, visually displaying the relationship between the two, allowing doctors to analyze changing patterns and trends, providing a basis for precise prosthesis adjustment. It also accumulates data for medical research, helping to further explore the principles and improved techniques of unicompartmental knee replacement.

[0017] 4. The prosthesis positioning component can accurately locate the prosthesis outward inclination angle and osteotomy line position, avoiding repeated testing, saving operation time, reducing risks, and at the same time reducing damage to the tissues around the knee joint, which is beneficial to postoperative recovery.

[0018] 5. The traditional method requires repeated testing of gaskets of different specifications to determine the tightness. This device measures and displays data in real time, quickly determines the optimal gasket specifications, shortens surgery time, reduces the patient's exposure time on the operating table, and reduces risks.

[0019] 6. The present invention adopts a purely mechanical structure without electronic components, which facilitates high-temperature sterilization and can be used repeatedly, thereby reducing medical costs and improving the durability and economy of the device.

[0020] Furthermore, the flexion angle measuring assembly includes a lever shaft, which is fixedly connected to the two side walls of the end of the through slot, a hinge sleeve is coaxially rotated at the center of the lever shaft, one end of the hinge sleeve is coaxially fixedly connected to the first bevel gear, a reset torsion spring is provided inside the hinge sleeve, the reset torsion spring is sleeved with the lever shaft, a flexion angle plate is fixedly connected to the outer wall of the hinge sleeve, and a plurality of arc contacts are fixedly connected to the top wall of the end of the flexion angle plate away from the hinge sleeve;

[0021] Several frame plates for dividing the through slots are fixedly connected inside the through slots. A first transmission shaft parallel to the through slot is provided inside the through slot. The first transmission shaft and the frame plates are both rotatably connected. The end of the first transmission shaft close to the lever shaft is coaxially fixedly connected to the second bevel gear. The second bevel gear is meshed with the first bevel gear. The middle part of the first transmission shaft is coaxially fixedly connected to the third bevel gear.

[0022] The basic design benefits from a lever shaft fixedly connected to the two side walls of the through-slot, forming a stable foundation for the flexion angle measurement assembly. When the femur and tibia move relative to each other, the hinge sleeve rotates around the lever shaft, driving the first bevel gear to rotate. This rotation is then transmitted through the second bevel gear and the first transmission shaft, causing the third bevel gear to rotate synchronously, achieving precise capture and transmission of angular changes.

[0023] Furthermore, a flexion angle instrument groove is opened in the middle of the gasket, and a first pointer shaft is rotatably connected to the center of the flexion angle instrument groove, and a flexion angle pointer is fixedly connected to the outer periphery of the top end of the first pointer shaft. The first pointer shaft is coaxially fixedly connected to the fourth bevel gear, and the fourth bevel gear is located above the third bevel gear and meshes with the third bevel gear. The flexion angle instrument groove is engraved with a flexion angle scale for indicating the flexion angle of the knee joint.

[0024] The basic solution offers the following benefits: 1. The design of the flexion meter slot allows the flexion pointer to intuitively indicate the knee flexion angle on the flexion scale. The surgeon can observe the position of the flexion pointer in real time and accurately understand changes in knee angle without complex calculations or assumptions, improving the convenience and accuracy of the surgical procedure.

[0025] 2. The fourth bevel gear meshes with the third bevel gear, ensuring that the angle changes of the flexion measurement assembly are accurately transmitted to the flexion instrument slot. This gear transmission method ensures high-precision angle measurement, making the measurement results more reliable, providing doctors with accurate angle data, and helping them make more precise judgments during surgery.

[0026] 3. The angulation instrument slot is located in the middle of the gasket, achieving close integration of the measurement and display components. This design reduces the transmission of measurement data and the risk of error, while also making the entire device more compact, making it easier to use in surgical environments and improving its overall performance and reliability.

[0027] Furthermore, the tension measuring assembly includes a semi-lunar groove cover, a measuring groove is opened at one end of the gasket close to the lever shaft, the semi-lunar groove cover and the measuring groove are slidably matched, a pre-tightening platform is opened on the inner wall of the measuring groove, a pre-tightening spring is fixedly connected to the pre-tightening platform, the top of the pre-tightening spring is fixedly connected to the bottom wall of the semi-lunar groove cover, a tooth chain is fixedly connected to the center of the bottom wall of the semi-lunar groove cover, pre-tightening hook plates are symmetrically fixedly connected to the left and right sides of the semi-lunar groove cover, and pre-tightening hook plates are provided on both sides of the gasket for limiting the movement of the semi-lunar groove cover;

[0028] A second transmission shaft parallel to the through slot is provided inside the through slot. The second transmission shaft is rotatably connected to the frame plate. One end of the second transmission shaft close to the measuring slot is coaxially fixedly connected to a transmission gear. The tooth chain is engaged with the transmission gear. The end of the tooth chain is fixedly connected to a horizontal spring. The other end of the horizontal spring is fixedly connected to the inner wall of the gasket. The middle part of the second transmission shaft is coaxially fixedly connected to the fifth bevel gear.

[0029] The beneficial effects of the basic solution are: 1. The semi-lunar groove cover slides with the measuring groove, and the preload spring provides a constant preload force to ensure that the tooth chain and the transmission gear are tightly engaged, thereby accurately reflecting the changes in the tightness of the knee joint at different angles. This provides doctors with accurate pressure data, helps to determine whether the prosthesis is installed properly, and avoids the knee joint being too tight or too loose after surgery.

[0030] 2. The meshing transmission between the tooth chain and the transmission gear can transmit and display the tightness changes of the knee joint in the full flexion range (0°-135°) in real time, providing doctors with complete dynamic data, optimizing prosthesis selection and installation, improving surgical results, and reducing the risk of postoperative abnormalities.

[0031] 3. The sliding fit between the top of the measuring slot and the half-moon slot cover, as well as the sliding fit between the preload hook plate and the slot, allows the assembly to accommodate different specifications of gaskets and knee joints of varying sizes, providing wide versatility and meeting diverse surgical requirements. Through the transmission gear and subsequent bevel gear transmission, the tightness data is ultimately displayed on the instrument panel, allowing the surgeon to visually observe changes in knee joint tightness, providing a precise reference for surgical procedures and improving surgical quality and effectiveness.

[0032] Furthermore, a tension meter slot symmetrically distributed with the flexion angle meter slot is opened in the middle of the gasket, and a second pointer shaft is rotatably connected to the center of the tension meter slot, and a tension pointer is fixedly connected to the outer periphery of the top end of the second pointer shaft, and a sixth bevel gear is coaxially fixedly connected to the bottom end of the second pointer shaft, and the sixth bevel gear is meshed with the fifth bevel gear. The diameter of the sixth bevel gear is smaller than that of the fifth bevel gear, and the sixth bevel gear is used to amplify the measured tension pressure between the femoral condyle and the tibial platform. The tension meter slot is engraved with a pressure scale for indicating the tension pressure of the knee joint, and the scale sectors on the tension meter slot are painted.

[0033] The basic solution offers the following benefits: 1. The tension indicator in the tension gauge slot intuitively indicates the tightness of the knee joint on the pressure scale. The surgeon can observe the indicator's position in real time to accurately determine the tightness of the knee joint, eliminating the need for complex calculations or guesswork, improving the convenience and accuracy of the surgical procedure.

[0034] 2. The sixth bevel gear has a smaller diameter than the fifth bevel gear, saving effort and amplifying the pressure between the femoral condyle and tibial plateau. Even minute pressure changes are clearly displayed through pointer deflection, improving measurement accuracy and providing doctors with accurate pressure data to help determine prosthetic fit and avoid overtightening or loosening the knee joint after surgery.

[0035] 3. The scale sectors on the tension gauge slot are painted with paint, clearly marking the appropriate tension pressure range. This design provides doctors with an intuitive reference, ensuring optimal knee joint tension and reducing the risk of postoperative complications.

[0036] 4. The tightness indicator on the pressure scale provides real-time indication, allowing doctors to adjust surgical procedures promptly to ensure the ideal tightness of the knee joint. This real-time feedback mechanism improves surgical accuracy and success rates, providing patients with better postoperative recovery.

[0037] Furthermore, protective covers are fixedly connected to the flexion angle instrument slot and the tension instrument slot, and the protective covers are provided with ventilation holes.

[0038] The beneficial effects of the basic solution are: 1. The protective cover is made of transparent material, which can effectively prevent external pollutants (such as dust, blood, etc.) from entering the flexion instrument slot and the tension instrument slot, ensuring the normal operation of components such as pointers and gears. At the same time, it is convenient to directly observe the pointer readings during surgery without removing the protective cover, thereby improving the convenience and safety of use.

[0039] 2. The vent holes on the protective cover balance the air pressure inside and outside the instrument slot, preventing deformation of the protective cover or pointer deviation caused by pressure differences, ensuring the accuracy of measurement data. The vent holes also help reduce the possibility of fogging inside the protective cover, further improving the clarity of the pointer reading, allowing doctors to obtain more accurate measurement information during surgery.

[0040] Furthermore, the curve recording assembly includes a rotating gear, which is coaxially fixedly connected to the end of the first transmission shaft away from the lever shaft, and the end of the through slot away from the lever shaft is fixedly connected to the recording slot, and the inside of the recording slot is rotatably connected to a paper cylinder shaft, and a paper cylinder is coaxially fixedly sleeved on the paper cylinder shaft, and the paper cylinder shaft passes through the inner wall of the recording slot and extends to the through slot and is coaxially fixedly connected to the recording gear, and the recording gear is meshed with the rotating gear, and the diameter of the recording gear is smaller than the diameter of the rotating gear;

[0041] A through-slot parallel to the recording slot is provided on the side wall of the recording slot near the second transmission shaft. The end of the second transmission shaft away from the lever shaft extends to the side wall of the through-slot and is rotatably connected to the inner wall of the gasket. A thread is provided on the portion of the second transmission shaft corresponding to the through-slot, and a nut is fitted on the thread. A burning needle is fixedly connected to the outer periphery of the nut, and the burning needle is slidably fitted in the through-slot. A switch cover is provided on the opening of the recording slot away from the recording gear.

[0042] The basic solution offers the following benefits: 1. The rotating gear is fixedly connected to the first transmission shaft, and the recording gear meshes with the rotating gear. The recording gear's diameter is smaller than the rotating gear's. This design accurately transmits changes in knee flexion angle to the recording slot. The paper tube shaft and paper tube ensure that the data curve is accurately recorded on the paper tube, providing surgeons with intuitive data on changes in knee tightness as the angle changes. This helps analyze the biomechanical properties of the knee joint, optimize prosthesis installation position and angle, and enhance surgical outcomes.

[0043] 2. The needle draws a data curve on the paper tube, visually demonstrating the relationship between knee joint tightness and flexion angle. By observing the shape and trend of the curve, doctors can quickly determine whether the change in knee joint tightness is normal, providing important evidence for surgical decision-making and reducing the risk of postoperative complications.

[0044] 3. The curve recording component adopts a purely mechanical structure without electronic components and can withstand high-temperature sterilization. All components such as gears, paper cylinder shafts, and recording needles are made of high-temperature resistant materials to ensure normal use after repeated sterilization, extending the service life of the device and reducing medical costs.

[0045] Furthermore, the outer circumference of the paper tube is pre-marked with horizontal and vertical axes, the horizontal axis represents the angle, and the vertical axis is parallel to the axis of the paper tube and represents the degree of tension and pressure.

[0046] The basic solution offers the following benefits: 1. The outer circumference of the paper tube is pre-marked with a horizontal axis (indicating angle) and a vertical axis (indicating tension and pressure), enabling a clear and intuitive recording of the curve showing changes in knee joint tightness versus angle. By observing the curve on the paper tube, doctors can quickly understand the changes in knee tightness at different flexion angles. This helps them more accurately analyze the biomechanical properties of the knee joint, optimize prosthesis installation position and angle, improve surgical outcomes, and provide precise data support for surgical procedures.

[0047] 2. The data curves recorded on the paper tube can be preserved long-term, providing an important basis for postoperative evaluation and research. Doctors can review the data during the operation at any time, analyze the surgical results, summarize the experience, provide reference for future operations, and promote technical improvements and research development of unicompartmental knee replacement.

[0048] 3. This data recording method does not rely on specific electronic devices or software and is widely applicable and compatible. Different hospitals and medical teams can easily use and interpret this recording method, promoting the exchange and sharing of medical technology.

[0049] Furthermore, the prosthesis positioning assembly includes an adjustment gear, an adjustment slot is formed in the middle of the gasket, the adjustment slot is connected to the middle of the through slot, a third transmission shaft is provided inside the through slot, the third transmission shaft and the frame plate are both rotationally engaged, the third transmission shaft is coaxially fixedly connected to the adjustment gear, and the outer periphery of the adjustment gear is slidably engaged with the adjustment slot;

[0050] The end of the third transmission shaft close to the lever shaft is coaxially fixedly connected to the inclination wheel, and a inclination groove connected to the through groove is opened in the middle of the gasket, the inclination groove and the inclination wheel slide in cooperation, and a number of inclination scales are engraved on the outer periphery of the inclination wheel, and a number of annularly arranged inclination magnetic pieces are fixedly connected to the side wall of the inclination wheel away from the adjusting gear, and the inclination magnetic pieces correspond to the inclination scales respectively, and a stabilizing magnetic piece is fixedly connected to the side wall corresponding to the inclination groove and the inclination magnetic piece, and the stabilizing magnetic piece and the inclination magnetic piece both slide in cooperation, and the seventh bevel gear is coaxially fixedly connected to the end of the third transmission shaft close to the lever shaft.

[0051] The basic solution offers the following benefits: 1. The connection between the adjustment gear and the third drive shaft allows the surgeon to precisely control the position of the incline wheel by rotating the adjustment gear. The incline scale on the outer periphery of the incline wheel and the sliding interaction between the incline magnet and the stabilizing magnet ensure precise measurement and positioning of the prosthesis' camber angle, improving the accuracy of prosthesis positioning.

[0052] 2. The sliding fit between the incline groove and the incline wheel, as well as the incline scale on the outer circumference of the incline wheel, provide the surgeon with intuitive angle indication. The surgeon can easily read the current camber angle, facilitating precise positioning during surgery and ensuring that the prosthesis is installed in accordance with surgical requirements.

[0053] 3. Because the device can withstand high-temperature sterilization, it can be reused multiple times. This not only reduces the generation of medical waste, but also lowers the hospital's procurement costs and improves resource utilization. At the same time, it ensures that each operation uses a reliable and strictly sterilized measuring tool, ensuring the safety and cost-effectiveness of the operation.

[0054] Furthermore, the inclination groove is fixedly connected with a protective shell, and an indicator line is engraved in the center of the protective shell.

[0055] The basic solution offers the following benefits: The protective shell, made of a transparent material, effectively prevents external contaminants from entering the incline groove, protecting components such as the incline wheel, incline magnet, and stabilizing magnet from contamination and damage. This ensures proper operation of the prosthetic positioning assembly and allows for direct observation of the indicator lines and incline scale during surgery without removing the protective shell, improving ease of use and safety.

[0056] Furthermore, an indicator groove is opened in the middle of the gasket, which points obliquely to the semi-lunar groove cover. A placement cylinder is rotatably connected in the indicator groove. The bottom wall of the placement cylinder is coaxially fixedly connected to a placement shaft. The placement shaft rotates in coordination with the indicator groove. The bottom end of the placement shaft is coaxially fixedly connected to an eighth bevel gear, and the eighth bevel gear is meshed with the seventh bevel gear.

[0057] The basic solution offers the following benefits: 1. The connection between the placement shaft and the eighth bevel gear, and the meshing of the eighth and seventh bevel gears, allows precise control of the placement barrel's rotation angle. This gear transmission ensures high-precision angle adjustment, enabling the laser pointer to accurately indicate the prosthesis' installation position, improving accuracy.

[0058] 2. The rotational coordination between the placement shaft and the indicator slot, as well as the meshing of the eighth and seventh bevel gears, creates a well-coordinated effect between the rotation of the placement cylinder and the third drive shaft. This linkage ensures precise adjustment of the prosthesis's outward inclination angle and osteotomy line, avoiding errors that may be introduced by manual operation.

[0059] 3. The magnetic plate on the bottom wall of the placement tube is magnetically fixed to the laser pointer, ensuring that the laser pointer can stably point to the required fixing hole location for prosthesis installation. The surgeon can intuitively follow the laser pointer during prosthesis installation, reducing uncertainty during surgery and improving efficiency and safety.

[0060] Furthermore, a placement magnetic sheet is fixedly connected to the bottom wall of the placement cylinder, and a laser indicator is magnetically fixedly connected to the placement magnetic sheet. The laser indicator is connected to the circuit through the placement magnetic sheet to light up the laser indicator.

[0061] The basic solution offers the following benefits: 1. The magnetic connection between the magnetic plate and the laser pointer makes installation and removal of the laser pointer quick and easy. Doctors can quickly install the laser pointer and flexibly adjust its position as needed, improving surgical efficiency.

[0062] 2. By placing a magnetic plate to connect the circuit, the laser pointer can light up stably and emit laser indication. This circuit connection method is not only stable and reliable, but also avoids the entanglement or damage problems that may occur with traditional wire connections, ensuring the stability and accuracy of laser indication.

[0063] 3. The laser pointer emits a laser beam that provides intuitive visual guidance, helping the surgeon precisely locate the implant. The surgeon can easily align the implant according to the laser pointer, reducing uncertainty and errors during surgery, and improving surgical accuracy and success rates.

[0064] Furthermore, the laser pointer indicates the two fixing holes required for installing the prosthesis and the position of the osteotomy line of the posterior condyle of the femoral condyle.

[0065] The beneficial effects of the basic solution are: 1. The laser pointer can accurately indicate the two fixation holes required for installing the prosthesis and the position of the posterior femoral condyle osteotomy line, providing doctors with intuitive visual references to ensure the accuracy of the prosthesis installation position and reduce surgical errors.

[0066] 2. The intuitive laser indication enables doctors to quickly determine the installation position of the prosthesis, reducing the time spent searching and confirming the position during surgery, making the surgical process more intuitive and controllable, and allowing doctors to operate more confidently. This visualization advantage is especially evident in complex or minimally invasive surgeries. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 1. This is an axonometric view of a unicompartmental knee joint tightness measuring device according to an embodiment of the present invention.

[0068] Figure 2 1. It is a top view of a unicompartmental knee joint tightness measuring device according to an embodiment of the present invention.

[0069] Figure 3 2. It is a side view of a unicompartmental knee joint tightness measuring device according to an embodiment of the present invention.

[0070] Figure 4 2. It is a side cross-sectional view of a unicompartmental knee joint tightness measuring device according to an embodiment of the present invention.

[0071] Figure 5 2. It is a top cross-sectional view of a unicompartmental knee joint tightness measuring device according to an embodiment of the present invention.

[0072] Figure 6 It is a front cross-sectional view of the half-moon groove cover in an embodiment of the present invention.

[0073] The reference numerals in the drawings of the specification include: 1, gasket; 2, adjusting gear; 3, inclination wheel; 4, tension meter slot; 5, flexion meter slot; 6, placement cylinder; 7, half-moon slot cover; 8, hook slot; 9, preload hook plate; 10, flexion plate; 11, arc contact; 12, preload platform; 13, switch cover; 14, pressure scale; 15, tension pointer; 16, flexion scale; 17, flexion pointer; 18, inclination magnetic plate; 19, frame plate; 20, second transmission shaft; 21, placement magnetic plate; 22, eighth bevel gear; 23, seventh bevel gear; 24, third transmission shaft; 25 , paper cylinder shaft; 26, recording gear; 27, paper cylinder; 28, stabilizing magnetic disc; 29, sixth bevel gear; 30, second pointer shaft; 31, fifth bevel gear; 32, preload spring; 33, tooth chain; 34, lever shaft; 35, reset torsion spring; 36, hinge sleeve; 37, thread; 38, nut; 39, burning needle; 40, placement shaft; 41, transmission gear; 42, horizontal spring; 43, first bevel gear; 44, second bevel gear; 45, first transmission shaft; 46, third bevel gear; 47, first pointer shaft; 48, fourth bevel gear; 49, rotating gear. DETAILED DESCRIPTION

[0074] The following is further described in detail through specific implementation methods:

[0075] Example 1

[0076] Basically as attached Figure 1 、 Figure 2 、 Figure 4 and Figure 6 Shown: A unicompartmental knee joint tightness measuring device includes a gasket 1, a through slot parallel to the gasket 1 is opened inside the gasket 1, a flexion angle measurement component and a tightness measurement component are provided at one end of the through slot, a curve recording component is provided at the other end of the through slot, and a prosthesis positioning component is fixedly connected to the top wall of the gasket 1.

[0077] The flexion angle measurement component is used to follow the movement of the gasket 1 between the femoral condyle and the tibial plateau to measure the angle changes of the femur and tibia and display the corresponding angle data. The flexion angle measurement component includes a lever shaft 34, which is welded to the two side walls of the end of the through groove. A hinge sleeve 36 rotates coaxially in the center of the lever shaft 34, and a first bevel gear 43 is coaxially welded to one end of the hinge sleeve 36. A reset torsion spring 35 is sleeved inside the hinge sleeve 36, and the reset torsion spring 35 is sleeved on the lever shaft 34 and one end is welded to the lever shaft 34. The other end of the reset torsion spring 35 is welded to the inner wall of the hinge sleeve 36. A flexion angle plate 10 is welded to the outer wall of the hinge sleeve 36, and a plurality of neatly arranged arc contacts 11 are welded to the top wall of the end of the flexion angle plate 10 away from the hinge sleeve 36.

[0078] Several frame plates 19 for dividing the through slots are welded inside the through slots. A first transmission shaft 45 parallel to the through slots is provided inside the through slots. The first transmission shaft 45 and the frame plates 19 are both rotatably connected. A second bevel gear 44 is coaxially welded to one end of the first transmission shaft 45 close to the lever shaft 34. The second bevel gear 44 is meshed with the first bevel gear 43. A third bevel gear 46 is coaxially welded to the middle of the first transmission shaft 45.

[0079] A flexion angle instrument slot 5 is opened in the middle of the gasket 1, and a first pointer shaft 47 is rotatably connected to the center of the flexion angle instrument slot 5. A flexion angle pointer 17 is integrally formed on the outer periphery of the top end of the first pointer shaft 47. The bottom end of the first pointer shaft 47 passes through the flexion angle instrument slot 5 and extends to the inside of the through slot and is coaxially welded with a fourth bevel gear 48. The fourth bevel gear 48 is located above the third bevel gear 46 and meshes with the third bevel gear 46. The flexion angle instrument slot 5 is engraved with a flexion angle scale 16 for indicating the flexion angle of the knee joint.

[0080] The tightness measuring component is used to measure the tightness data of the knee joint that changes with the angle between the femoral condyle and the tibial plateau and display the tightness data of the knee joint. The tightness measuring component includes a semi-lunar groove cover 7, a measuring groove is opened at one end of the gasket 1 close to the lever shaft 34, the semi-lunar groove cover 7 slides in cooperation with the measuring groove, a pre-tightening platform 12 is opened on the inner wall of the measuring groove, a pre-tightening spring 32 is welded on the pre-tightening platform 12, the top of the pre-tightening spring 32 is welded to the bottom wall of the semi-lunar groove cover 7, a tooth chain 33 is welded to the center of the bottom wall of the semi-lunar groove cover 7, and pre-tightening hook plates 9 are symmetrically welded on the left and right sides of the semi-lunar groove cover 7. Hook grooves 8 are opened on both sides of the gasket 1, and the hook grooves 8 slide in cooperation with the pre-tightening hook plates 9 respectively. The pre-tightening hook plates 9 are used to hook the semi-lunar groove cover 7 to compress the pre-tightening spring 32.

[0081] A second transmission shaft 20 parallel to the through slot is provided inside the through slot. The second transmission shaft 20 is rotatably connected to the frame plate 19. A transmission gear 41 is coaxially welded to one end of the second transmission shaft 20 close to the measuring slot. The tooth chain 33 passes under the transmission gear 41 and engages with the transmission gear 41. A horizontal spring 42 is welded to the end of the tooth chain 33. The other end of the horizontal spring 42 is welded to the inner wall of the gasket 1. A fifth bevel gear 31 is coaxially welded to the middle of the second transmission shaft 20.

[0082] A tension meter slot 4 symmetrically distributed with the flexion angle meter slot 5 is also provided in the middle of the gasket 1. A second pointer shaft 30 is rotatably connected to the center of the tension meter slot 4. A tension pointer 15 is integrally formed on the outer periphery of the top end of the second pointer shaft 30. The bottom end of the second pointer shaft 30 passes through the tension meter slot 4 and extends to the inside of the through slot and is coaxially welded with a sixth bevel gear 29. The sixth bevel gear 29 is meshed with the fifth bevel gear 31. The diameter of the sixth bevel gear 29 is smaller than that of the fifth bevel gear 31. The sixth bevel gear 29 is used to amplify the measured tension pressure between the femoral condyle and the tibial plateau. The tension meter slot 4 is engraved with a pressure scale 14 for indicating the tension pressure of the knee joint, and the scale sectors on the tension meter slot 4 are painted with paint, and the paint is used to indicate the appropriate tension pressure.

[0083] The flexion meter slot 5 and the tension meter slot 4 are both bonded with protective covers, and the protective covers are both provided with ventilation holes.

[0084] The curve recording component is used to record the data curve of the tightness of the knee joint changing with the angle.

[0085] Prosthesis positioning component, used to locate the prosthesis outward inclination angle and osteotomy line position.

[0086] The specific implementation process is as follows: In a single femoral condylar replacement surgery, the doctor needs to first perform osteotomy and drill a hole, and then install the prosthesis. Before installing the prosthesis, the doctor will use a semi-lunar gasket 1 of different thicknesses to insert between the prosthesis and the tibial plateau, and feel the tightness and pressure of the knee joint through the dragging resistance to determine whether the osteotomy depth is sufficient. However, in the existing surgical process, doctors often only test the tightness and pressure of the patient's knee joint at 20° extension and 90° flexion. However, the commonly used knee joint angle during walking is 30°-60°. If the changes in tightness and pressure within these angles are not detected and adjusted, it may cause an increased possibility of knee joint collision, inflammation or dislocation after surgery.

[0087] Therefore, the present invention measures the knee joint tightness pressure at the corresponding angle while measuring the knee joint flexion angle, and records it. When the doctor pushes the knee joint to rotate, the posterior femoral condyle presses down and first presses against the arc contact 11, and the femoral condyle as a whole slides on the top of the semilunar groove cover 7. As the flexion angle increases, the posterior femoral condyle pushes the flexion plate 10 and the hinge sleeve 36 to rotate on the lever shaft 34. The reset torsion spring 35 in the hinge sleeve 36 is compressed, and the first bevel gear 43 outside the hinge sleeve 36 rotates to drive the second bevel gear 44 and the first transmission shaft 45 to rotate. Then, the flexion rotation angle is proportionally transmitted to the third bevel gear 46 and the fourth bevel gear 48. The fourth bevel gear 48 drives the first pointer shaft 47 to rotate. The flexion pointer 17 on the first pointer shaft 47 follows and rotates at the same angle as the flexion rotation angle, thereby indicating the current flexion angle on the flexion instrument slot 5 and the flexion scale 16. Figure 1 and Figure 6 shown.

[0088] At the same time, as the flexion angle continues to change, the femoral condyle slides on the top of the meniscus cover 7 as a whole. Affected by the curvature of the femoral condyle and the internal pressure of the knee joint, the femoral condyle pushes the meniscus cover 7 to move into the measuring slot, thereby squeezing the preload spring 32 that has been preloaded by the horizontal spring 42 and the preload hook plate 9. The toothed chain 33 at the bottom of the meniscus cover 7 is constrained by the horizontal spring 42, and drives the transmission gear 41 and the second transmission shaft 20 to rotate when moving downward. The fifth bevel gear 31 on the second transmission shaft 20 transmits the rotation to the sixth bevel gear 29 and amplifies it. The sixth bevel gear 29 and the second pointer shaft 30 are driven to rotate and turn the tension pointer 15. The tension pointer 15 indicates the current knee joint tension pressure on the tension meter slot 4. Its value is converted according to the compression of the preload spring 32 and Hooke's law. Since the doctor needs to observe in real time, different scale sectors on the tension meter slot 4 are painted with different pigments. The green pigment is used to indicate the appropriate tension pressure, which is approximately between 90-110N. Combined with the following: Figure 2 and Figure 4 shown.

[0089] Both instrument slots are covered with transparent protective covers, which effectively protect the pointers and scales inside the slots, preventing external contaminants from entering and causing a decrease in display accuracy. The vent holes in the protective covers balance the water vapor pressure between the slots and the outside world during high-temperature and high-pressure sterilization, preventing water vapor accumulation inside the protective covers, which could corrode the pointers and scales and obscure the display. Based on these functions, doctors can conveniently use this device to measure the tightness of a patient's knee joint during continuous flexion angle changes during surgery, thereby helping to optimize the prosthesis installation position and angle, improving surgical effectiveness, and reducing time consumption.

[0090] Example 2

[0091] The difference from the above embodiment is that, in combination with Figure 5 As shown: the curve recording assembly includes a rotating gear 49, which is coaxially welded to the end of the first transmission shaft 45 away from the lever shaft 34, and a recording groove is welded to the end of the through groove away from the lever shaft 34. The recording groove is rotatably connected to the paper cylinder shaft 25, and a coaxial pin on the paper cylinder shaft 25 is connected to the paper cylinder. The paper cylinder shaft 25 passes through the inner wall of the recording groove and extends to the through groove and is coaxially welded with a recording gear 26. The recording gear 26 is engaged with the rotating gear 49, and the diameter of the recording gear 26 is smaller than the diameter of the rotating gear 49.

[0092] A through-slot parallel to the recording groove is provided on the side wall of the recording groove near the second transmission shaft 20. The end of the second transmission shaft 20 away from the lever shaft 34 extends to the side wall of the through-slot and is rotatably connected to the inner wall of the gasket 1. A thread 37 is provided on the portion of the second transmission shaft 20 corresponding to the through-slot, and a nut 38 is fitted on the thread 37. A burning needle 39 is welded to the outer periphery of the nut 38, and the burning needle 39 is slidably fitted with the through-slot. The opening of the recording groove away from the recording gear 26 is clamped with a switch cover 13.

[0093] The outer circumference of the paper tube is pre-marked with horizontal and vertical coordinate axes. The horizontal coordinate axis represents the angle, and the vertical coordinate axis is parallel to the paper tube axis 25 to represent the degree of tension and pressure.

[0094] The specific implementation process is as follows: Based on real-time detection, the transmission effect of the first transmission shaft 45 and the second transmission shaft 20 is utilized. The first transmission shaft 45 transmits the flexion angle change movement to the rotating gear 49. The rotating gear 49 drives the recording gear 26 to rotate and amplify the movement. This is to convert the 90° movement of the flexion angle change into a 360° movement to make the recorded pressure-angle curve more detailed. The recording gear 26 drives the paper tube shaft 25 and the paper tube to rotate. At the same time, the second transmission shaft 20 transmits the pressure change movement to the thread 37. The rotation of the thread 37 drives the movement of the nut 38. Since the nut 38 and the burning needle 39 thereon are constrained by the burning groove, the nut 38 can only move axially in a straight line. The movement distance of the burning needle 39 on the paper tube reflects the pressure change value as shown in FIG. Figure 4 and Figure 5 shown.

[0095] The paper tube is pre-marked with horizontal and vertical coordinates, which can help doctors analyze the structure and curvature of the patient's femoral condyle of the knee joint after surgery, thereby helping patients customize more detailed treatment plans and providing data support for in-depth research on unicompartmental knee replacement.

[0096] Example 3

[0097] The difference from the above embodiment is that, in combination with Figure 3As shown: the prosthesis positioning assembly includes an adjusting gear 2, an adjusting slot is opened in the middle of the gasket 1, the adjusting slot is connected to the middle of the through slot, a third transmission shaft 24 is installed inside the through slot, the third transmission shaft 24 and the frame plate 19 are both rotated together, the third transmission shaft 24 is coaxially welded with the adjusting gear 2, the outer periphery of the adjusting gear 2 extends to the outside through the adjusting slot and slides with the adjusting slot, the end of the third transmission shaft 24 close to the lever shaft 34 is coaxially welded with the inclination wheel 3, the gasket 1 is opened in the middle and connected to the through slot The inclination groove of the inclination wheel 3 slides together, and a number of inclination scales are engraved on the outer periphery of the inclination wheel 3. A number of annularly arranged inclination magnetic pieces 18 are welded on the side wall of the inclination wheel 3 away from the adjusting gear 2. The inclination magnetic pieces 18 correspond to the inclination scales respectively. Stabilizing magnetic pieces 28 are welded on the side walls corresponding to the inclination groove and the inclination magnetic pieces 18. The stabilizing magnetic pieces 28 and the inclination magnetic pieces 18 slide together, and the seventh bevel gear 23 is coaxially welded on the end of the third transmission shaft 24 close to the lever shaft 34.

[0098] A protective shell is bonded to the opening of the inclination groove, and an indicator line is engraved in the center of the protective shell.

[0099] An indicator groove is opened in the middle of the gasket 1, which points obliquely to the semi-lunar groove cover 7. A placement cylinder 6 is rotatably connected in the indicator groove. The bottom wall of the placement cylinder 6 is coaxially fixedly connected with a placement shaft 40. The placement shaft 40 passes through the center of the indicator groove and extends into the through groove and rotates with the indicator groove. The bottom end of the placement shaft 40 is coaxially welded with the eighth bevel gear 22, and the eighth bevel gear 22 is meshed with the seventh bevel gear 23.

[0100] A placement magnetic sheet 21 is welded to the inner bottom wall of the placement tube 6, and a laser indicator is magnetically fixedly connected to the placement magnetic sheet 21. The laser indicator lights up the laser indication by connecting the circuit through the placement magnetic sheet 21. The laser indicator indicates the two fixing holes required for installing the prosthesis and the position of the osteotomy line of the posterior condyle of the femoral condyle.

[0101] The specific implementation process is as follows: During the operation, the femoral condyle of some patients is in a natural outward-tilted state, and the prosthesis to be installed also needs to be installed outward-tilted. However, during the osteotomy and drilling process before installation, instruments need to be used to repeatedly measure and mark the drilling position and osteotomy line, which undoubtedly prolongs the operation time.

[0102] By clamping the half-moon groove cover 7 of the present invention in the knee joint, the adjusting gear 2 can be rotated, and the adjusting gear 2 rotates the third transmission shaft 24. The third transmission shaft 24 with the inclination wheel 3 displays the current inclination angle through the protective shell. The other end of the third transmission shaft 24 drives the seventh bevel gear 23 and rotates the eighth bevel gear 22. The eighth bevel gear 22 drives the placement shaft 40 and the placement cylinder 6 to rotate in the indicator groove. The rotation angle is the same as the rotation angle of the adjusting gear 2. The stabilizing magnetic piece 28 attracts the inclination magnetic piece 18 to attract the inclination wheel 3 to lock the rotation angle of the third transmission shaft 24, which helps stabilize the laser indicator. Figure 3 and 4shown.

[0103] A matching laser pointer is placed in the placement tube 6, and the two poles of the laser pointer's circuit are connected and fixed by the placement magnetic piece 21. The laser pointer rotates at a corresponding inclination angle as the placement tube 6 rotates, thereby indicating the position of the prosthesis fixing hole and the required osteotomy line with the corresponding inclination angle on the femoral condyle, which is convenient for the doctor to mark and verify, and improves the efficiency and quality of the operation.

[0104] The present invention adopts a purely mechanical structure without electronic components and can withstand high-temperature sterilization. Each component can ensure normal use after repeated sterilization, thereby extending the service life of the device and reducing medical costs.

[0105] Specific experimental process:

[0106] 1. Experimental Objectives

[0107] ① Verify the accuracy of the device’s dynamic measurement over the full range of 0°-135° (compared to optical tracking standards).

[0108] ② Evaluate the quantification ability of tightness (compared with the error of traditional feel method).

[0109] ③ Test the laser positioning accuracy of the prosthesis (osteotomy line deviation value).

[0110] 2. Experimental Samples

[0111] Twelve sets of specimen knee joints were collected, with an age of 65±7 years and moderate osteoarthritis (KL grade III); four sets of artificial knee joint models, with curvature radius: medial 28-36mm / lateral 55-75mm.

[0112] 3. Test equipment

[0113] The device of the present invention combines tightness / angle measurement with laser positioning; an optical motion capture system (Qualisys) with dynamic angle / clearance standards, with an accuracy of ±0.01mm / ±0.1°; a mechanical sensor (Kistler) for real-time contact pressure verification, with an accuracy of ±0.5N; and a micro-CT (Scanco) for osteotomy line positioning error measurement, with an accuracy of ±5μm.

[0114] 4. Experimental Procedure

[0115] ①Dynamic measurement accuracy verification

[0116] Optical markers were installed on the specimen femoral condyle, and the device of the present invention was placed in the joint gap. A motor was used to stably drive the knee flexion from 0° to 135° (at a speed of 10° / s). The device of the present invention recorded the flexion angle / tightness and converted the gap value using Hooke's law. The optical system synchronously recorded the gap value, and the difference between the two was calculated.

[0117] ②Quantitative comparison of tightness and looseness

[0118] Three orthopedic surgeons used traditional gaskets to assess the same knee joint (0° and 90° positions); the device of the present invention measured the same position; the mechanical sensor output the actual pressure value as a benchmark.

[0119] ③Light positioning accuracy test

[0120] The device of the present invention projects the osteotomy line and the position of the fixing hole by laser; drills a hole in the femoral condyle according to the laser guidance; and compares the deviation of the hole position with the preset coordinate by micro-CT scanning.

[0121] 5. Experimental Data

[0122] As shown in the following table:

[0123] Table 1. Comparison of dynamic measurement errors (n=12)

[0124]

[0125] Table 2. Comparison of quantification ability of tightness and looseness

[0126]

[0127]

[0128] Table 3. Surgical efficiency and positioning accuracy

[0129]

[0130] 6. Experimental Conclusion

[0131] The maximum error of the device in continuous measurement at 0°-135° is only 1.7% (≤1.6% in the range of 30°-60°), successfully covering the key angles of gait and solving the blind spot problem of pad wear of traditional methods. The mechanical display error of tightness is 3.5±1.2N (77% lower than the error of doctor's touch), and the specificity of green zone judgment is 100%, which avoids postoperative complications caused by over-tightness and over-looseness of the prosthesis from the root. Measurement and positioning are completed in a single insertion, saving time ≥64%, reducing the number of gasket replacements by 85%, and the laser positioning accuracy is 0.15mm, significantly reducing the risk of osteotomy. After 200 times of high-temperature sterilization (120°C), the gear transmission error is still <0.08mm, confirming the long-term stability of the pure mechanical design in the surgical environment.

[0132] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0133] The above is only an embodiment of the present invention. Common knowledge such as the known specific structures and characteristics in the scheme is not described in detail here. Ordinary technicians in the field are aware of all common technical knowledge in the technical field of the invention before the application date or priority date, can obtain all existing technologies in the field, and have the ability to apply conventional experimental means before that date. Ordinary technicians in the field can improve and implement this scheme in combination with their own abilities under the inspiration given by this application. Some typical known structures or known methods should not become obstacles for ordinary technicians in the field to implement this application. It should be pointed out that for those skilled in the art, without departing from the structure of the present invention, several variations and improvements can be made, which should also be regarded as the scope of protection of the present invention. These will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A unicompartmental knee joint tightness measuring device, comprising a gasket (1), characterized in that: A through slot parallel to the gasket (1) is provided inside the gasket (1); a flexion angle measuring component and a tightness measuring component are provided at one end of the through slot, and a curve recording component is provided at the other end of the through slot; a prosthesis positioning component is fixedly connected to the top wall of the gasket (1); A flexion angle measurement component is used to follow the movement of the gasket (1) between the femoral condyle and the tibial plateau to measure the angle changes of the femur and tibia and display the corresponding angle data; A tightness measurement component, used for measuring knee joint tightness data that changes with angle between the femoral condyle and the tibial plateau and displaying the knee joint tightness data; Curve recording component, used to record the data curve of knee joint tightness changing with angle; Prosthesis positioning component, used to locate the prosthesis outward inclination angle and osteotomy line position.

2. The unicompartmental knee joint tightness measuring device according to claim 1, characterized in that: The flexion angle measuring assembly includes a lever shaft (34), the lever shaft (34) is fixedly connected to the two side walls of the end of the through slot, a hinge sleeve (36) is coaxially rotated at the center of the lever shaft (34), one end of the hinge sleeve (36) is coaxially fixedly connected to a first bevel gear (43), a reset torsion spring (35) is provided inside the hinge sleeve (36), the reset torsion spring (35) is sleeved with the lever shaft (34), a flexion angle plate (10) is fixedly connected to the outer wall of the hinge sleeve (36), and a plurality of arc contacts (11) are fixedly connected to the top wall of the flexion angle plate (10) away from the hinge sleeve (36); A plurality of frame plates (19) for dividing the through slots are fixedly connected inside the through slots. A first transmission shaft (45) parallel to the through slots is provided inside the through slots. The first transmission shaft (45) and the frame plate (19) are both rotatably connected. An end of the first transmission shaft (45) close to the lever shaft (34) is coaxially fixedly connected to a second bevel gear (44). The second bevel gear (44) is meshed with the first bevel gear (43). A third bevel gear (46) is coaxially fixedly connected to the middle of the first transmission shaft (45).

3. The unicompartmental knee joint tightness measuring device according to claim 2, characterized in that: A flexion angle meter slot (5) is provided in the middle of the gasket (1), a first pointer shaft (47) is rotatably connected to the center of the flexion angle meter slot (5), a flexion angle pointer (17) is fixedly connected to the outer periphery of the top end of the first pointer shaft (47), a fourth bevel gear (48) is coaxially fixedly connected to the first pointer shaft (47), the fourth bevel gear (48) is located above the third bevel gear (46) and meshes with the third bevel gear (46), and a flexion angle scale (16) for indicating the flexion angle of the knee joint is engraved on the flexion angle meter slot (5).

4. The unicompartmental knee joint tightness measuring device according to claim 1, characterized in that: The tension measuring assembly comprises a half-moon groove cover (7), a measuring groove is provided at one end of a gasket (1) close to a lever shaft (34), the half-moon groove cover (7) is slidably matched with the measuring groove, a pre-tightening platform (12) is provided on the inner wall of the measuring groove, a pre-tightening spring (32) is fixedly connected to the pre-tightening platform (12), the top end of the pre-tightening spring (32) is fixedly connected to the bottom wall of the half-moon groove cover (7), a tooth chain (33) is fixedly connected to the center of the bottom wall of the half-moon groove cover (7), pre-tightening hook plates (9) are symmetrically fixedly connected to the left and right sides of the half-moon groove cover (7), and pre-tightening hook plates (9) are provided on both sides of the gasket (1) for limiting the movement of the half-moon groove cover (7); A second transmission shaft (20) parallel to the through slot is provided inside the through slot. The second transmission shaft (20) and the frame plate (19) are both rotatably connected. One end of the second transmission shaft (20) close to the measuring slot is coaxially fixedly connected to a transmission gear (41). One end of a toothed chain (33) is meshed with the transmission gear (41). A horizontal spring (42) is fixedly connected to the end of the toothed chain (33). The other end of the horizontal spring (42) is fixedly connected to the inner wall of the gasket (1). A fifth bevel gear (31) is coaxially fixedly connected to the middle of the second transmission shaft (20).

5. The unicompartmental knee joint tightness measuring device according to claim 4, characterized in that: The gasket (1) is provided with a tension meter slot (4) symmetrically distributed with the flexion angle meter slot (5) in the middle thereof. The tension meter slot (4) is rotatably connected to a second pointer shaft (30) in the center thereof. A tension pointer (15) is fixedly connected to the outer periphery of the top end of the second pointer shaft (30). A sixth bevel gear (29) is coaxially fixedly connected to the bottom end of the second pointer shaft (30). The sixth bevel gear (29) is meshed with the fifth bevel gear (31). The diameter of the sixth bevel gear (29) is smaller than that of the fifth bevel gear (31). The sixth bevel gear (29) is used to amplify the measured tension pressure between the femoral condyle and the tibial plateau. A pressure scale (14) for indicating the tension pressure of the knee joint is engraved on the tension meter slot (4), and the scale sector on the tension meter slot (4) is painted with paint.

6. The unicompartmental knee joint tightness measuring device according to claim 5, characterized in that: The flexion meter slot (5) and the tension meter slot (4) are both fixedly connected with protective covers, and the protective covers are both provided with vent holes.

7. The unicompartmental knee joint tightness measuring device according to claim 1, characterized in that: The curve recording assembly includes a rotating gear (49), the rotating gear (49) is coaxially fixedly connected to the end of the first transmission shaft (45) away from the lever shaft (34), the end of the through slot away from the lever shaft (34) is fixedly connected to the recording slot, the inside of the recording slot is rotatably connected to a paper cylinder shaft (25), a paper cylinder is coaxially fixedly sleeved on the paper cylinder shaft (25), the paper cylinder shaft (25) passes through the inner wall of the recording slot and extends to the through slot and is coaxially fixedly connected to a recording gear (26), the recording gear (26) is meshed with the rotating gear (49), and the diameter of the recording gear (26) is smaller than the diameter of the rotating gear (49); A recording groove parallel to the recording groove is provided on a side wall of the recording groove close to the second transmission shaft (20); an end of the second transmission shaft (20) away from the lever shaft (34) extends to the side wall of the groove and is rotatably connected to the inner wall of the gasket (1); a thread (37) is provided on the portion of the second transmission shaft (20) corresponding to the recording groove; a nut (38) is fitted on the thread (37); a recording needle (39) is fixedly connected to the outer periphery of the nut (38); the recording needle (39) is slidably fitted with the recording groove; a switch cover (13) is provided on the opening of the recording groove away from the recording gear (26).

8. The unicompartmental knee joint tightness measuring device according to claim 7, characterized in that: The outer periphery of the paper tube is pre-marked with horizontal and vertical coordinate axes, the horizontal coordinate axis represents the angle, and the vertical coordinate axis is parallel to the paper tube axis (25) to represent the size of the tightness and pressure.

9. The unicompartmental knee joint tightness measuring device according to claim 1, characterized in that: The prosthesis positioning component includes an adjusting gear (2), an adjusting groove is formed in the middle of the gasket (1), the adjusting groove is communicated with the middle of the through groove, a third transmission shaft (24) is provided inside the through groove, the third transmission shaft (24) and the frame plate (19) are both rotationally matched, the third transmission shaft (24) is coaxially fixedly connected to the adjusting gear (2), and the outer periphery of the adjusting gear (2) is slidingly matched with the adjusting groove; The end of the third transmission shaft (24) close to the lever shaft (34) is coaxially fixedly connected to the inclination wheel (3), the middle of the gasket (1) is provided with an inclination groove connected to the through groove, the inclination groove and the inclination wheel (3) are slidably matched, the outer periphery of the inclination wheel (3) is engraved with a plurality of inclination scales, a side wall of the inclination wheel (3) away from the adjustment gear (2) is fixedly connected to a plurality of annularly arranged inclination magnetic pieces (18), the inclination magnetic pieces (18) and the inclination scales respectively correspond, the side wall corresponding to the inclination groove and the inclination magnetic piece (18) is fixedly connected to a stabilizing magnetic piece (28), the stabilizing magnetic piece (28) and the inclination magnetic piece (18) are both slidably matched, and the end of the third transmission shaft (24) close to the lever shaft (34) is coaxially fixedly connected to the seventh bevel gear (23).

10. The unicompartmental knee joint tightness measuring device according to claim 9, characterized in that: The inclination groove is fixedly connected with a protective shell, and an indicator line is engraved in the center of the protective shell.

11. The unicompartmental knee joint tightness measuring device according to claim 9, characterized in that: The gasket (1) has an indicator groove in the middle thereof which is obliquely pointed toward the half-moon groove cover (7). A placement cylinder (6) is rotatably connected in the indicator groove. A placement shaft (40) is coaxially fixedly connected to the bottom wall of the placement cylinder (6). The placement shaft (40) is rotatably matched with the indicator groove. An eighth bevel gear (22) is coaxially fixedly connected to the bottom end of the placement shaft (40). The eighth bevel gear (22) is meshed with the seventh bevel gear (23).

12. The unicompartmental knee joint tightness measuring device according to claim 11, characterized in that: The inner bottom wall of the placement cylinder (6) is fixedly connected with a placement magnetic sheet (21), and a laser indicator is magnetically fixedly connected to the placement magnetic sheet (21). The laser indicator is connected to the circuit through the placement magnetic sheet (21) to light up the laser indicator.

13. The unicompartmental knee joint tightness measuring device according to claim 12, characterized in that: The laser pointer indicates the two fixation holes required for installing the prosthesis and the position of the osteotomy line of the posterior femoral condyle.

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