Drafting device fitting knee joint instantaneous center track

Abstract

The invention provides a traction device for fitting a knee joint instantaneous center track, and relates to the technical field of orthopedic medical instruments, the traction device comprises a thighbone fixing ring, a tibia fixing ring, an instantaneous center fitting mechanism and an automatic traction mechanism, a plurality of first through holes are uniformly distributed in the thighbone fixing ring, and a plurality of first fastening nuts are arranged on the first through holes; a plurality of second through holes are uniformly distributed in the tibia fixing ring, and a plurality of second fastening nuts are arranged on the second through holes; a swinging connecting piece is arranged on the instantaneous center fitting mechanism, a sliding block is connected to the swinging connecting piece, the center of the sliding block fits the instantaneous center of the knee joint of the human body, and the sliding block is connected into the guide groove in a sliding mode; the automatic drafting mechanism comprises an electric push rod, the electric push rod is provided with a guide rod, the guide rod extends or shortens to adjust the drafting angle of the instantaneous center fitting mechanism, and then the buckling angle of the knee joint is adjusted. The device has the advantages that the drafting orthopedic precision is high, the drafting angle is automatically adjusted, and the instantaneous center of the knee joint is fitted.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of orthopedic medical devices, in particular to a stretching device fitting the instantaneous center trajectory of a knee joint. BACKGROUND

[0002] At present, there are many knee joint deformity problems in orthopedic clinics, such as knee joint flexion deformity, knee joint extension contracture, knee varus, knee valgus, etc. The tension stress principle proposed by Ilizarov points out that the stress generated by the controlled continuous pulling of living tissues can stimulate cell division and tissue regeneration. By stimulating the growth ability of the patient's own tissues, the knee joint deformity problem can be gradually corrected.

[0003] Ilizarov orthopedic technology is a minimally invasive external fixation technology. The knee joint orthopedic device developed based on Ilizarov orthopedic technology can correct the deformity of the knee joint. The common knee joint orthopedic device is hinged with an adjusting hinge. When installing the knee joint orthopedic device through minimally invasive surgery, it is often necessary to deflect or slide around the long axis of the limb in order to place the tibia in a reasonable joint position. After the operation, due to the change in the relative position of the tibia and the femur, the regeneration of the condylar cartilage, meniscus and ligament, and postoperative pain, the patient cannot independently complete the flexion action and needs the assistance of medical personnel to manually perform the flexion action of the lower limb.

[0004] In addition, the existing knee joint orthopedic device also has the problem that the rotation center of the hinge does not match the actual rotation curve of the knee joint, which increases the probability of misalignment of the knee joint orthopedic device during deformity correction and makes the deformity correction less accurate, affecting the deformity correction effect of patients with knee joint deformity.

[0005] Part of the knee joint stretching device also has the problems of multiple components, time-consuming and laborious assembly, and inability to meet the needs of fitting the instantaneous center of the human knee joint. Therefore, there is an urgent need in the art for a stretching device that has high orthopedic accuracy, can automatically adjust the stretching angle, and fits the instantaneous center trajectory of the knee joint. SUMMARY

[0006] The purpose of the present application is to provide a stretching device fitting the instantaneous center trajectory of a knee joint.

[0007] The embodiments of the present application are implemented as follows:

[0008] The application provides a stretching device for fitting the center of acceleration of a knee joint, which comprises a femur fixing ring, a tibia fixing ring, a center of acceleration fitting mechanism, and an automatic stretching mechanism.

[0009] In a preferred embodiment of the application, the two ends of the center of acceleration fitting mechanism are respectively provided with a first adapter plate and a second adapter plate; the first adapter plate is fixed to the femur fixing ring through a fastening screw, a first support rod is threadedly connected to the first adapter plate, a first joint is arranged at the tail end of the first support rod, and a first guide groove is hingedly connected to the first joint; the second adapter plate is fixed to the tibia fixing ring through a fastening screw, a first guide column is arranged on the end face of the second adapter plate, and the first guide column is slidably connected to the first guide groove.

[0010] In a preferred embodiment of the application, a second support rod is threadedly connected to the first adapter plate, a second joint is arranged at the tail end of the second support rod, a first positioning rod is fixedly connected to the second joint, and the first positioning rod is connected to a second positioning rod.

[0011] In a preferred embodiment of the application, a waist-shaped hole is further arranged on the first adapter plate, a threaded adjusting rod is arranged in the waist-shaped hole, a second positioning rod is fixedly connected to the lower portion of the threaded adjusting rod; an adjusting connecting rod is arranged between the first positioning rod and the second positioning rod, and the adjusting connecting rod adjusts the distance between the first positioning rod and the second positioning rod.

[0012] In a preferred embodiment of the application, the second positioning rod is coaxially connected to a swing joint through a swing shaft, a second guide groove is connected to the lower portion of the swing joint, a sliding block is slidably connected to the second guide groove, a second guide column is arranged on the sliding block, and the second guide column is slidably connected to the first guide groove.

[0013] In a preferred embodiment of the present application, the second adapter sleeve at the front end of the electric push rod is hingedly connected to the first hinge member through a conversion joint, and the second adapter sleeve at the rear end of the electric push rod is threadedly connected to the threaded positioning rod.

[0014] In a preferred embodiment of the present application, the two end faces of the positioning sleeve are provided with nuts, the nuts are engaged with the external threads provided on the threaded positioning rod, a screw is provided on the positioning sleeve, the screw is arranged through the positioning sleeve, and the screw is in abutment with the threaded positioning rod.

[0015] In a preferred embodiment of the present application, the two sides of the electric push rod are provided with guide rods, one end of the guide rod is connected to an adapter joint through a first adapter sleeve, the adapter joint is hingedly connected to the first hinge member, and the first hinge member is fixed to the femoral fixation ring.

[0016] In a preferred embodiment of the present application, the electric push rod is electrically connected with a control circuit, the control circuit is configured to control the extension length of the guide rod of the electric push rod according to a remote control signal, so as to control the stretching angle of the instant center fitting mechanism.

[0017] In a preferred embodiment of the present application, the upper space of the second guide groove is hingedly connected with a connecting rod, and the connecting rod is also hingedly connected with a swing connecting member.

[0018] The present application has the following beneficial effects:

[0019] 1. The two ends of the instant center fitting mechanism are respectively fixed to the femoral fixation ring and the tibial fixation ring, the swing connecting member is provided on the instant center fitting mechanism, the sliding block is connected to the swing connecting member, the center of the sliding block fits the instant center of the human knee joint, the sliding block is slidingly connected in the guide groove, the sliding block slides along the guide groove, and the movement curve of the center of the sliding block fits the instant center curve of the knee joint, so that the stretching orthopedic precision is high.

[0020] 2. The two ends of the automatic stretching mechanism are respectively hingedly connected with the femoral fixation ring and the tibial fixation ring, the automatic stretching mechanism has an electric push rod, the electric push rod has a guide rod, the stretching angle of the instant center fitting mechanism is adjusted by the extension or shortening of the guide rod, the stretching angle of the automatic stretching device is automatically adjusted, so as to automatically adjust the flexion angle of the knee joint, and the knee joint stiffness problem of the patient is improved.

[0021] 3. The electric push rod is electrically connected with a control circuit, and the control circuit is arranged to automatically control the guide rod extension length of the electric push rod according to a remote control signal, so as to control the stretching angle of the instantaneous center fitting mechanism, and the instantaneous center fitting mechanism automatically controls the swinging angle of the instantaneous center fitting mechanism according to the remote control operation of medical staff, automatically adjusts the stretching angle, and further adjusts the flexion angle of the knee joint. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0023] Figure 1 It is a schematic diagram of the overall structure of the stretching device fitting the instantaneous center trajectory of the knee joint of the present application.

[0024] Figure 2 It is a schematic diagram of the femur fixing ring connection mode of the stretching device fitting the instantaneous center trajectory of the knee joint of the present application.

[0025] Figure 3 It is a schematic diagram of the tibia fixing ring connection mode of the stretching device fitting the instantaneous center trajectory of the knee joint of the present application.

[0026] Figure 4 It is a schematic diagram of the electric push rod and auxiliary stretching guide rod of the stretching device fitting the instantaneous center trajectory of the knee joint of the present application.

[0027] Figure 5 It is a schematic diagram of the instantaneous center fitting mechanism of the stretching device fitting the instantaneous center trajectory of the knee joint of the present application.

[0028] Figure 6 It is a schematic diagram of the stretching process of the stretching device fitting the instantaneous center trajectory of the knee joint of the present application.

[0029] DRAWINGS

[0030] 1, first femur fixation ring; 2, first articulating member; 3, electric push rod; 4, first threaded rod; 5, second articulating member; 6, first Kirschner wire; 7, first adapter sleeve; 8, second Kirschner wire; 9, second adapter sleeve; 10, guide rod; 11, guide support member; 12, first tibia fixation ring; 13, second threaded rod; 14, first guide slot; 15, first joint; 16, first support rod; 17, synchronous positioning plate; 18, second femur fixation ring; 19, second tibia fixation ring; 20, third tibia fixation ring; 21, first fastening nut; 22, adapter joint; 23, threaded positioning rod; 24, first adapter plate; 25, second adapter plate; 26, first positioning rod; 27, second positioning rod; 28, swing joint; 29, swing shaft; 30, adjustment link; 31, second guide slot; 32, sliding block; 33, swing connecting member; 34, simulated knee instantaneous center; 35, fitted knee instantaneous center curve; 36, second fastening nut; 37, second support rod; 38, connecting rod. DETAILED DESCRIPTION

[0031] So that the objects, technical solutions and advantages of the embodiments of the present application are more apparent, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative work fall within the scope of protection of the present application.

[0033] It should be noted that: similar reference numerals and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0034] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly placed when the product of the application is used, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" and the like are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0035] In addition, the terms "horizontal", "vertical" and the like do not mean that the components must be absolutely horizontal or vertical, but can be slightly inclined. For example, "horizontal" only means that it is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0036] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "arrangement", "installation", "connection", "connection" should be broadly understood, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0037] The present application provides a stretching device fitting the center of instantaneous trajectory of knee joint to solve the technical problems that the existing knee joint stretching device cannot fit the center of instantaneous trajectory of human knee joint, the probability of knee joint orthopedic misplacement increases when correcting deformity, the deformity correction is not accurate enough and the bending angle of the stretching device cannot be automatically adjusted. Therefore, the present application provides the following specific embodiments.

[0038] The present embodiment provides a stretching device fitting the center of instantaneous trajectory of knee joint, referring to Figures 1 to 6 , comprising a femur fixing ring, a tibia fixing ring, a center of instantaneous fitting mechanism, an automatic stretching mechanism, referring to Figure 1The femur fixing ring is fixed on the femur by means of a Kirschner wire, the tibia fixing ring is fixed on the tibia by means of a Kirschner wire, the instant center fitting mechanism is arranged between the femur fixing ring and the tibia fixing ring, the instant center fitting mechanism is arranged on one side or opposite sides of the femur fixing ring and the tibia fixing ring, the connecting pieces of the instant center fitting mechanism present an unstable parallelogram structure, so that the instant center fitting mechanism swings synchronously with the instant center of the knee joint, and the instant center fitting mechanism has a guide groove, a sliding block is slidably connected to the guide groove, the center of the sliding block simulates the instant center of the human knee joint, the movement track of the center of the sliding block is fitted with the instant center curve of the human knee joint, so that the instant center of the instant center fitting mechanism is adapted to the instant center of the human knee joint, to accurately fit the instant center of the human knee joint, the movement track of the center of the sliding block fits the instant center curve of the knee joint, and the accuracy and flexibility of the orthopedic are improved.

[0039] The two ends of the automatic stretching mechanism are respectively hinged to the femur fixing ring and the tibia fixing ring, and the arrangement position of the automatic stretching mechanism and the arrangement position of the instant center fitting mechanism are at a right angle with the center angle of the femur fixing ring, the automatic stretching mechanism comprises an electric push rod 3, the inside of the electric push rod 3 is provided with a guide rod, the extension of the guide rod makes the tibia fixing ring swing around the instant center of the instant center fitting mechanism, the stretching angle of the automatic stretching mechanism is adjusted, so that the flexion angle of the knee joint is adjusted, thereby stretching the tibia forward and backward to assist in deformity correction and improve the stiffness problem of the knee joint.

[0040] The femur fixing ring is arranged as a half ring or a whole ring, referring to Figure 2 A plurality of first through holes are uniformly distributed on the femur fixing ring, a plurality of first fastening nuts 21 are arranged on the first through holes, in the embodiment, the number of the first fastening nuts arranged on the same femur fixing ring is two, and the axis of the two first fastening nuts 21 is the diameter of the femur fixing ring.

[0041] The first fastening nut 21 is fastened with a first Kirschner wire 6, the first fastening nut 21 has a hexagonal square, the bottom surface of the hexagonal square has a slot hole, the inner contour of the slot hole is matched with the outer shape of the first Kirschner wire 6, so that the first Kirschner wire 6 is fastened on the first fastening nut 21, and the first Kirschner wire 6 penetrates the femur.

[0042] Specifically, the femur fixing ring comprises a first femur fixing ring 1 and a second femur fixing ring 18, a plurality of first threaded rods 4 are arranged between the first femur fixing ring 1 and the second femur fixing ring 18, in the embodiment, the number of the first threaded rods 4 is four, and the first threaded rods 4 are uniformly arranged in the circumferential direction of the first femur fixing ring 1, thereby improving the fixing stability of the femur fixing ring.

[0043] Preferably, the first femur fixing ring 1 and the second femur fixing ring 18 are provided with the first Kirschner wire 6, and the first Kirschner wire 6 provided on the first femur fixing ring 1 is at right angles with the first Kirschner wire 6 provided on the second femur fixing ring 18; further improving the fixing stability of the femur fixing ring.

[0044] The tibia fixing ring is provided as a half ring or a whole ring, referring to Figure 3 The tibia fixing ring is provided with a plurality of second through holes, and a plurality of second fastening nuts 36 are provided on the second through holes. In the embodiment, the number of the second fastening nuts 36 provided on the same tibia fixing ring is two, and the axis of the two second fastening nuts 36 is the diameter of the tibia fixing ring.

[0045] The second fastening nut 36 is fastened with the second Kirschner wire 8, and the second fastening nut 36 has a hexagonal side, the bottom surface of the hexagonal side has a slot hole, the inner contour of the slot hole is matched with the outer shape of the second Kirschner wire 8, so that the second Kirschner wire 8 is fastened on the second fastening nut 36, and the second Kirschner wire 8 penetrates the tibia.

[0046] Specifically, the tibia fixing ring includes a first tibia fixing ring 12, a second tibia fixing ring 19 and a third tibia fixing ring 20, a plurality of second threaded rods 13 are evenly distributed between the first tibia fixing ring 12 and the second tibia fixing ring 19, and a plurality of second threaded rods 13 are also evenly distributed between the second tibia fixing ring 19 and the third tibia fixing ring 20. In the embodiment, the number of the second threaded rods 13 is eight, the second threaded rods 13 are evenly distributed on the two side end surfaces of the second tibia fixing ring 19 in the circumferential direction, and the second threaded rods 13 provided on the two side end surfaces of the second tibia fixing ring 19 are connected with the first tibia fixing ring 12 and the third tibia fixing ring 20, respectively. When correcting the knee joint deformity, it has a large contact area, is convenient for deflection or sliding around the long axis of the limb, places the intercondylar anterior region and the intercondylar posterior region of the tibia at a reasonable joint position, and further matches the meniscus with the femoral condyle cartilage, which is beneficial to the regeneration of the femoral condyle cartilage, the meniscus and the ligament tissue after orthopedic correction, has high stretching orthopedic accuracy, improves the deformity correction effect of the patient with knee joint deformity, and has high orthopedic accuracy.

[0047] The first tibia fixing ring 12, the second tibia fixing ring 19 and the third tibia fixing ring 20 are all provided with the second Kirschner wire 8, and the second Kirschner wires 8 provided on adjacent two femur fixing rings are at right angles, so that the fixing stability of the femur fixing ring is improved; the second Kirschner wire 8 is fixed on the second fastening nut 36; in the embodiment, the number of the second fastening nuts 36 provided on the same tibia fixing ring is set to two, and the axis center line of the two second fastening nuts 36 is the diameter of the tibia fixing ring.

[0048] The two ends of the instant center fitting mechanism are fixed on the femur fixing ring and the tibia fixing ring respectively, referring to Figure 1 、 Figure 5 and Figure 6 , the instant center fitting mechanism is provided with a swing connecting piece 33, the swing connecting piece 33 is connected with a sliding block 32, the center of the sliding block 32 simulates the instant center 34 of the knee joint, the center moving track of the sliding block 32 fits the instant center curve 35 of the knee joint, the sliding block 32 is slidingly connected in the guide groove, so that the sliding block 32 slides forward and backward in the guide groove, the stretching stability of the stretching device is enhanced, the accuracy of the stretching orthopedics is improved, and the deformity correction effect of the patient with knee joint deformity is improved.

[0049] Specifically, the two ends of the instant center fitting mechanism are respectively provided with a first adapter plate 24 and a second adapter plate 25, referring to Figure 5 ; the first adapter plate 24 is fixed on the femur fixing ring through a fastening screw, two first adapter plates 24 are symmetrically distributed on the second femur fixing ring 18, a first support rod 16 is threadedly connected to the first adapter plate 24, a first joint 15 is arranged at the tail end of the first support rod 16, and a first guide groove 14 is hingedly connected to the first joint 15; the first guide groove 14 is slidingly connected with a first guide column arranged on the second adapter plate 25.

[0050] A second support rod 37 is threadedly connected to the first adapter plate 24, the plane where the axis of the first support rod 16 and the second support rod 37 is located is at an acute angle with the plane where the first support rod 16 and the threaded adjusting rod are located; a second joint is arranged at the tail end of the second support rod 37, a first positioning rod 26 is fixedly connected to the second joint, the first positioning rod 26 is connected with a second positioning rod 27, the second positioning rod 27 is fixedly connected to a threaded adjusting rod, and the threaded adjusting rod is arranged in a waist-shaped hole.

[0051] The first adapter plate 24 is also provided with a waist-shaped hole, a threaded adjusting rod is arranged in the waist-shaped hole, the setting direction of the waist-shaped hole is parallel to the adjacent side of the first supporting rod 16, the threaded adjusting rod is arranged in the waist-shaped hole, and the position of the threaded adjusting rod is adjusted; and then the position of the threaded adjusting rod is adjusted according to the center of instantaneous motion of the knee joint of different patients.

[0052] The first positioning rod 26 and the second positioning rod 27 are provided with an adjusting connecting rod 30, and the adjusting connecting rod 30 adjusts the distance between the first positioning rod 26 and the second positioning rod 27. Figure 5 The adjusting connecting rod 30 includes an adjusting stud and a square nut, the adjusting stud is threadedly connected with the square nut, the square nut is rotated in opposite directions, the length of the adjusting connecting rod is elongated or shortened, the distance between the first positioning rod 26 and the second positioning rod 27 is adjusted, the center of instantaneous motion of the center of instantaneous motion fitting mechanism is matched with the center of instantaneous motion of the knee joint of the human body, and the center of instantaneous motion fitting mechanism can be adjusted according to the different positions of the center of instantaneous motion of the knee joint of different patients.

[0053] The second supporting rod 37 is also hingedly connected with a swing shaft seat, a swing connecting piece 33 is connected below the swing shaft seat, a sliding block 32 is connected below the swing connecting piece 33, a second guide column is arranged on the sliding block 32, the second guide column is slidably connected with the first guide slot 14, the center of the second guide column is matched with the center of instantaneous motion of the knee joint of the human body, and the center of the second guide column is the center of the sliding block; the center of the second guide column simulates the center of instantaneous motion of the knee joint 34, and the motion track of the center of the second guide column fits the center of instantaneous motion curve 35 of the knee joint.

[0054] The second positioning rod 27 is coaxially connected with the swing joint 28 through the swing shaft 29, the swing joint 28 and the threaded adjusting rod are synchronously moved by rotating the adjusting connecting rod 30, the swing joint 28 is moved and adjusted according to the different positions of the center of instantaneous motion of the knee joint of different patients, a second guide slot 31 is connected below the swing joint 28, a sliding block 32 is slidably connected on the second guide slot 31, a third guide column is further arranged on the other side of the sliding block 32, and the center of the third guide column is coaxially arranged with the center of the second guide column; the center of the third guide column is matched with the center of instantaneous motion of the knee joint of the human body, the center of the third guide column simulates the center of instantaneous motion of the knee joint 34, and the motion track of the center of the third guide column fits the center of instantaneous motion curve 35 of the knee joint.

[0055] The upper space of the second guide groove 31 is hinged with a connecting rod 38, and the connecting rod 38 is also hinged with the swing connecting piece 33. When the patient performs the action of bending or straightening the knee, the instantaneous center fitting mechanism performs regular swing action with the edge formed by the first positioning rod 26 and the second positioning rod 27 as the relatively immobile edge and the swing shaft 29 as the shaft, and the two ends of the connecting rod are respectively hinged with the second guide groove 31 and the swing connecting piece 33, thereby improving the mechanism stability of the instantaneous center fitting mechanism.

[0056] The knee joint instantaneous center trajectory of the patient is obtained by making the patient in the correction position and the patient in the upright position with the help of the medical staff, using an X-ray camera or a CT machine to take pictures of the knee joint of the patient from the upright state to the bending state, and taking a picture of the knee joint of the patient every 5° of bending; then using a bone contour extraction module and an instantaneous center point extraction module to extract the knee joint instantaneous center of the patient, the bone contour extraction module extracts the tibia feature point position of the patient at each angle by using a contour tracking algorithm, and the instantaneous center point extraction module obtains the knee joint motion instantaneous center point by the normal intersection method according to the tibia feature point position. The knee joint motion instantaneous center point and the knee joint instantaneous center trajectory are described in detail in some public documents, which are prior art and will not be described here.

[0057] Or the optical motion capture technology is used to obtain the knee joint motion instantaneous center point and the knee joint instantaneous center trajectory, which are prior art and will not be described here.

[0058] The instantaneous center fitting mechanisms symmetrically distributed on both sides of the femur fixing ring are provided with synchronous positioning plates 17, and synchronous positioning rods are arranged on the synchronous positioning plates 17, as shown in Figure 1 and Figure 5 The synchronous positioning rods enable the instantaneous center fitting mechanisms on both sides of the femur fixing ring to move synchronously, thereby improving the stability of the instantaneous center fitting mechanism and the stretching orthopedic accuracy.

[0059] One end of the automatic stretching mechanism is hinged with the first femur fixing ring 1, and the other end of the automatic stretching mechanism is hinged with the first tibia fixing ring 12, as shown in Figure 1 and Figure 4 The automatic stretching mechanism includes an electric push rod 3, and the electric push rod 3 is arranged to control the guide rod extension length of the electric push rod 3 according to the electric signal of the control circuit, so as to adjust the stretching angle of the instantaneous center fitting mechanism and further adjust the flexion angle of the knee joint.

[0060] Specifically, the electric push rod 3 is provided with a second adapter sleeve 9 at both front and rear ends, the second adapter sleeve 9 is a smooth cylinder or a cylinder with a clamping notch, the second adapter sleeve 9 is internally provided with an internal thread, the electric push rod 3 is provided with an external thread column at both front and rear ends, the external thread column at the rear end of the electric push rod 3 is fixed on the elongated guide rod of the electric push rod; the second adapter sleeve 9 at the rear end of the electric push rod 3 is also connected with a threaded positioning rod 23, part or all of the threaded positioning rod 23 is provided with an external thread, so as to selectively adjust the extension length of the threaded positioning rod 23 according to the placement positions of the femur fixing ring and the tibia fixing ring of different patients.

[0061] The threaded positioning rod 23 is sleeved on a positioning sleeve, both end faces of the positioning sleeve are provided with nuts, the nuts are engaged with the external thread provided on the threaded positioning rod 23, so that the threaded positioning rod 23 is fixed on the positioning sleeve; preferably, the positioning sleeve is provided with a screw, the screw is penetrated in the positioning sleeve, and the screw abuts against the threaded positioning rod 23, so as to improve the fixing firmness of the positioning sleeve.

[0062] The positioning sleeve is hinged on a second hinge 5, the second hinge 5 is fixed on the first tibia fixing ring 12, so that when the guide rod extension length of the electric push rod 3 changes, the tibia fixing ring drives the tibia to slide and swing around the condyle, and the flexion angle of the knee joint is adjusted.

[0063] The second adapter sleeve 9 at the front end of the electric push rod 3 is hinged on a first hinge 2 through a conversion joint, the first hinge 2 is hinged on a first femur fixing ring 1, the external thread column provided at the front end of the electric push rod 3 is threadedly connected with the second adapter sleeve 9, the tail end of the conversion joint is provided with an external thread matched with the internal thread of the second adapter sleeve 9, when the guide rod extension length of the electric push rod 3 changes, the conversion joint provided at the front end of the electric push rod 3 rotates around the first hinge 2, and then the electric push rod 3 swings up and down along the conversion joint.

[0064] Preferably, the two sides of the electric push rod 3 are provided with guide rods 10, which are smooth stainless steel rods, and the part connected with the first adapter sleeve 7 is provided with external threads, one end of the guide rod 10 is connected to the adapter joint 22 through the first adapter sleeve 7, the adapter joint 22 is hinged to the first hinge 2, and the first hinge 2 is fixed to the femoral fixation ring; in this embodiment, the first hinge 2 is fixed to the first femoral fixation ring 1, the first hinge 2 is symmetrically distributed on both sides of the electric push rod 3, and the guide rod 10 is symmetrically distributed on both sides of the electric push rod 3, thereby improving the running stability of the electric push rod 3.

[0065] The guide rod 10 is provided in the guide support 11, which is hinged to the second hinge 5, and when the electric push rod 3 is extended or shortened, the guide rod 10 slides along the guide support 11, which helps to guide the stretching device to swing around the instant fitting mechanism, thereby improving the running stability of the electric push rod 3.

[0066] The electric push rod 3 is electrically connected to the control circuit, which is configured to control the length of the guide rod of the electric push rod 3 according to the remote control signal, thereby controlling the flexion angle of the instant fitting mechanism; specifically, the control circuit is provided with a radio frequency signal receiver, which includes a signal amplifier, a filter and a signal processor, the signal amplifier receives the remote control signal and amplifies the received radio signal, the filter filters out noise signals and stray signals and transmits the signals to the signal processor, the signal processor demodulates the received signals and transmits the demodulated signals to the electric push rod, thereby controlling the extension or shortening of the guide rod of the electric push rod 3, realizing automatic adjustment of the stretching angle of the stretching device, automatically adjusting the flexion angle of the lower extremity of the patient, and improving the problem of knee joint stiffness of the patient.

[0067] Preferably, the current input end of the electric push rod 3 is provided with a Hall current sensor, which is electrically connected to the control circuit, the Hall current sensor detects the potential difference generated by the current passing through the conductor under the action of the magnetic field, and converts the potential difference into a voltage signal output, thereby realizing detection of the current size; the Hall current sensor is electrically connected to the control circuit and transmits the current signal detected to the control circuit, and the Hall current sensor detects the change of the current value of the electric push rod by detecting the change of the potential difference generated by the current to the conductor.

[0068] The control circuit is also electrically connected with an alarm, and the control circuit has a set current threshold value; when the Hall current sensor detects that the current value of the electric push rod reaches the set current threshold value, the control circuit controls the alarm red light to flash and the alarm to beep, prompting medical staff that the extension or shortening resistance of the electric push rod 3 is too large, and paying attention to the health condition of the lower limbs of the patient to prevent the patient from being injured in the ligament or meniscus due to the distraction dislocation.

[0069] The above only is the preferred embodiment of the present application, and is not used to limit the present application, and the present application can have various changes and changes for the person skilled in the art. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A distraction device for fitting a centric trajectory of a knee joint, characterized in that, The application relates to a knee joint automatic stretching device. The device comprises a femur fixing ring, a tibia fixing ring and a instantaneous center fitting mechanism. The femur fixing ring is uniformly provided with a plurality of first through holes, and a plurality of first fastening nuts (21) are arranged on the first through holes to fasten first Kirschner wires (6). The tibia fixing ring is uniformly provided with a plurality of second through holes, and a plurality of second fastening nuts (36) are arranged on the second through holes to fasten second Kirschner wires (8). The instantaneous center fitting mechanism is fixed at two ends of the femur fixing ring and the tibia fixing ring respectively, and is provided with a swing connecting piece (33) and a sliding block (32) connected to the swing connecting piece (33).

2. A distraction device for fitting the centrode trajectory of a knee joint according to claim 1, characterized in that: The sliding block (32) is centrally fitted to the instantaneous center of the human knee joint and is slidingly connected to a guide groove. The automatic stretching mechanism is hingedly connected at two ends of the femur fixing ring and the tibia fixing ring respectively and comprises an electric push rod (3) having a guide rod. The guide rod is elongated or shortened to adjust the stretching angle of the instantaneous center fitting mechanism and further adjust the flexion angle of the knee joint.

3. A distraction device for fitting the centrode of a knee joint according to claim 2, characterized in that: The two ends of the instantaneous center fitting mechanism are respectively provided with a first adapter plate (24) and a second adapter plate (25).

4. A distraction device for fitting the centrode of a knee joint according to claim 3, characterized in that: The first adapter plate (24) is fixed on the femur fixing ring through fastening screws and is threadedly connected with a first supporting rod (16) having a first joint (15) arranged at the tail end of the first supporting rod (16). The second adapter plate (25) is fixed on the tibia fixing ring through fastening screws and is provided with a first guide column arranged on the end face of the second adapter plate (25).

5. A distraction device for fitting the centrode trajectory of a knee joint according to claim 4, characterized in that: The first guide column is slidingly connected with the first guide groove (14). The first adapter plate (24) is threadedly connected with a second supporting rod (37) having a second joint arranged at the tail end of the second supporting rod (37). The second joint is fixedly connected with a first positioning rod (26) connected with a second positioning rod (27). The first adapter plate (24) is further provided with a waist-shaped hole in which a threaded adjusting rod is arranged. The lower part of the threaded adjusting rod is fixedly connected with the second positioning rod (27). An adjusting connecting rod (30) is arranged between the first positioning rod (26) and the second positioning rod (27) to adjust the distance between the first positioning rod (26) and the second positioning rod (27). The second positioning rod (27) is coaxially connected with a swing joint (28) through a swing shaft (29). The lower part of the swing joint (28) is connected with a second guide groove (31) slidingly connected with the sliding block (32). The sliding block (32) is provided with a second guide column slidingly connected with the first guide groove (14).

6. A distraction device for fitting the centrode trajectory of a knee joint according to claim 1, characterized in that: The electric push rod (3) is provided with a second adapter sleeve (9) at both ends, the second adapter sleeve (9) is internally provided with a female thread, and the electric push rod (3) is provided with a male thread column at both ends, which is matched with the female thread; The second adapter sleeve (9) provided at the front end of the electric push rod is hinged to the first hinge member through a conversion joint; The second adapter sleeve (9) provided at the rear end of the electric push rod is threadedly connected to a threaded positioning rod (23); Part or all of the threaded positioning rod (23) is provided with an external thread, and the threaded positioning rod (23) is sleeved on a positioning sleeve.

7. A distraction device for fitting the centric trajectory of the knee joint according to claim 6, characterized in that: Both ends of the positioning sleeve are provided with nuts, which are engaged with the external thread provided on the threaded positioning rod; The positioning sleeve is provided with a screw, the screw is arranged in the positioning sleeve, and the screw is in abutment with the threaded positioning rod.

8. A distraction device for fitting a centric trajectory of a knee joint according to claim 6 or 7, characterized in that: Both sides of the electric push rod (3) are provided with guide rods (10), one end of the guide rod (10) is connected to an adapter joint (22) through a first adapter sleeve (7), the adapter joint (22) is hinged to the first hinge member (2), and the first hinge member (2) is fixed on the femoral fixation ring.

9. The distractor of claim 1, wherein: The electric push rod (3) is electrically connected with a control circuit, and the control circuit is arranged to control the guide rod extension length of the electric push rod according to a remote control signal, so as to control the distraction angle of the instantaneous center fitting mechanism.

10. A distraction device for fitting the centrode trajectory of a knee joint according to claim 5, characterized in that: The upper space of the second guide groove (31) is hinged with a connecting rod (38), and the connecting rod (38) is further hinged with a swing connecting piece (33).

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