Three-branch orthopedic external fixation support

Abstract

The application discloses a three-branch orthopedic external fixing support, which comprises two oppositely arranged fixing rings, three supporting arms which are evenly arranged between the two fixing rings, and a self-expanding adjusting mechanism arranged on the supporting arms, characterized in that one end of the supporting arm is connected with one of the fixing rings through a hinge, the other end of the supporting arm is directly connected with a nut which is fixedly arranged, the axis of the nut is perpendicular to the supporting arm, the nut is sleeved on a screw rod which is rotatably arranged on the other fixing ring, one end of the screw rod is connected with a screw rod driving motor, and the nut is arranged apart from the fixing ring on which the screw rod is arranged. The device has the advantages of compact and light structure, small interference to the perspective image, high degree of automation, multi-degree-of-freedom adjustment, simple and compact structure and the like, and can better meet the rigidity adjustment requirement of the support.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of orthopedic external fixation devices, in particular to a three-branch orthopedic external fixation support. BACKGROUND

[0002] Orthopedic external fixation support is a medical device used for fracture treatment and bone reconstruction, usually composed of an external fixator and bone pins. The external fixator is mainly composed of one or more steel rings, support rods and connecting rods. The steel ring is fixed under the skin around the injured part and connected to the external fixation frame through the connecting rod and the support rod. The design of the external fixator can be adjusted according to different fracture types and injury sites. Bone pins are small metal pins or fixators that further fix the fracture ends. They are inserted into the bone body through the skin and muscle to increase support and stability. The main function of the external fixation support is to stabilize the fractured bone ends in the correct position and promote fracture healing. It can provide immediate support and stability, effectively reducing the risk of fracture fragment displacement and early joint stiffness; it is most commonly used for the recovery of limb fractures.

[0003] For the orthopedic external fixation support used for human limb recovery, the most common is a structure scheme composed of two fixation rings and six connecting arms, such as the fixation device structure disclosed in patents US6030386A and CN201810623485.8, etc. The structure has six telescopic adjustable support arms hinged between the two fixation rings. When used, metal bone pins (Kirschner pins) are used to fix and connect the two ends of the fixation ring with the bone blocks at both ends of the patient's limb fracture. During the recovery process, the length of the six support arms can be adjusted as needed to generate six degrees of freedom relative motion of the two fixation rings, which can assist in correcting the reduction recovery of the fracture. This six-branch structure fixation support, although convenient to adjust, has the defects of complex structure, high cost, heavy device weight affecting recovery, and the device itself easily affecting CT imaging interference, etc. due to too many supports.

[0004] CN201810253067.4 discloses a free connection type three branched chain parallel orthopedic external fixation support, which is composed of two fixing rings and three branched chains. The fixing ring is provided with uniformly distributed connecting holes in the circumferential direction, and the branched chain is provided with two driving moving pairs, one rotating pair and one ball pair. The two fixing rings can be fixedly connected with the bone blocks at both ends of the fracture through metal bone pins. By adjusting the driving moving pairs of each branched chain according to a certain rule, six degrees of freedom relative motion between the fixing rings can be generated to realize the reduction of the fracture. The three branched chains of the external fixation support can be freely connected between the fixing rings, which is convenient and fast to install. The number of branched chains is less than that of general parallel external fixation supports, and the whole is light and has little interference with the perspective image. The driving pairs of the branched chains can accurately indicate the driving displacement and can be locked, so that the reduction and fixation of the fracture are more accurate. However, the three branched chain fixation support still has the following defects: 1. Manual adjustment is needed during adjustment, and the degree of automation is poor. 2. Although multi-degree of freedom adjustment can be achieved, the mechanical structure is relatively complex and not compact. 3. The stiffness of the branched chain cannot be adjusted, and the different needs for the stiffness of the support before and after the rehabilitation period of the patient cannot be met. SUMMARY

[0005] In view of the above-mentioned deficiencies of the prior art, the technical problem to be solved by the present application is: how to provide a three-armed orthopedic external fixation support which can improve the degree of automation, is light and has little interference with the perspective image, can achieve multi-degree of freedom adjustment and has a simpler and more compact structure, and can meet the stiffness adjustment needs of the branched chain.

[0006] In order to solve the above technical problems, the present application adopts the following technical solutions:

[0007] A three-armed orthopedic external fixation support, comprising two oppositely arranged fixing rings, three support arms are connected between the two fixing rings in a uniform distribution, and a self-expanding adjustment mechanism is arranged on the support arm, characterized in that one end of the support arm is connected to one of the fixing rings through a hinge, the other end is directly connected to a nut, the axis of the nut is perpendicular to the support arm, the nut is sleeved on a screw rod which is rotatably arranged on the other fixing ring, one end of the screw rod is provided with a screw rod driving motor, and the nut is spaced apart from the fixing ring where the screw rod is installed.

[0008] Thus, the structure of the present scheme is a three-branch structure, compared with the conventional six-branch type fixing support, the weight is reduced, and the interference with the perspective image is reduced. At the same time, compared with the existing CN201810253067.4 three-branch type fixing support, the screw drive motor is increased, the rotation control of the screw rod can be realized, manual adjustment is not required, and the automation degree is improved. At the same time, the nut and the support arm are directly connected in the present application, the setting of a hinge structure is reduced, the structure is more simple and compact, and the nut in the present scheme is directly constrained by the support arm during translational control, the guide rail structure and the nut cooperation on the fixing ring of the installed screw rod are not required, and the processing difficulty is reduced. Through computer simulation test, since the rotation of the screw rod and the stretching and shrinking of the support arm are controllable, the nut can realize translation under the control of both, and the function of multi-degree-of-freedom adjustment can also be realized.

[0009] Further, one end of the support arm is connected through a U-shaped hinge and a corresponding fixed ring. This is more convenient for the control of the self-stretching and shrinking of the support arm.

[0010] Further, the U-shaped hinge is installed on the mounting protrusions uniformly arranged along the outer periphery of the corresponding fixed ring. This is more convenient for installation and reduces the weight of the device.

[0011] Further, the screw rod is installed on a U-shaped screw rod seat, and the screw rod seat is installed between the mounting protrusions uniformly arranged along the outer periphery of the corresponding fixed ring.

[0012] This is more convenient for installation and reduces the weight of the device.

[0013] Further, the fixed ring is provided with a plurality of through holes. This is convenient for installing the beijie needle, and is beneficial to reduce the weight of the device.

[0014] Further, the support arm includes two sections that are mutually butted, and the self-stretching and shrinking adjustment mechanism includes a stretching and shrinking motor coaxially installed at the butt joint end of one section of the support arm, the stretching and shrinking motor has a threaded main shaft coaxial with the support arm, and the threaded main shaft is screwed into a screw hole coaxially arranged at the butt joint end of the other section of the support arm.

[0015] Thus, the rotation of the stretching and shrinking motor can drive the threaded main shaft to rotate along the screw hole, and stretching and shrinking adjustment is realized.

[0016] Further, a pressure sensor for detecting the axial pressure of the support arm is further arranged on the support arm. Thus, the pressure received by the support arm can be better detected and fed back for control.

[0017] Further, a variable stiffness adjustment joint is coaxially arranged and installed on the support arm.

[0018] Thus, the stiffness adjustment of the support arm can be conveniently realized, so that the stiffness requirement of the device under different rehabilitation degrees is met.

[0019] Further, the variable stiffness adjusting joint comprises a fixed disc fixed relative to the support arm and an adjusting disc rotatable relative to the support arm, the fixed disc and the adjusting disc are annular and coaxial with the support arm, the fixed disc and the adjusting disc each have an opposite mounting end face, the mounting end face of the adjusting disc is uniformly provided with a plurality of arc-shaped sliding grooves, one end of the arc-shaped sliding grooves gradually approaches the axis in a spiral shape, each arc-shaped sliding groove is provided with a mounting frame of a frame structure, one end of the mounting frame extends outward to form a sliding block slidingly fitted in the arc-shaped sliding groove, a roller is horizontally arranged in the inner frame of the mounting frame, the mounting end face of the fixed disc is provided with a plurality of leaf springs corresponding to the mounting frame, inner ends of the leaf springs are fixedly arranged at the axis of the mounting end face of the fixed disc, and outer ends of the leaf springs are press-connected to the rollers in the mounting frame.

[0020] In this way, the fixed disc and the adjusting disc are actually connected by the leaf springs. When the stiffness needs to be changed, the adjusting disc is only rotated to change the position of the sliding block of the mounting frame in the arc-shaped sliding groove, so that the distance of the mounting frame from the axis is changed, the length and the elastic force of the leaf spring are changed, the stiffness is adjusted, and the variable stiffness adjusting joint has the advantages of simple structure and reliable stiffness adjustment.

[0021] Further, the outer circumferential surface of the adjusting disc or the fixed disc is further provided with angle scale lines.

[0022] In this way, the size of the angle adjustment amount can be conveniently observed and determined, and the control is convenient.

[0023] Further, one end of the fixed disc is a connecting end connected to the support arm body, and the other end is outwardly convex in the middle, and the mounting end face and the leaf springs are arranged on the end face of the outwardly convex part.

[0024] In this way, the fixed disc and the support arm are conveniently connected.

[0025] Further, a cylindrical adjusting disc shell is fixedly arranged outside the adjusting disc, and one end of the adjusting disc shell is used to be connected to the support arm body. In this way, the installation and connection of the adjusting disc are better facilitated.

[0026] Further, the other end of the adjusting disc shell extends inward to form a closed end and surrounds one end of the mounting frame away from the arc-shaped sliding groove, and the inner side of the closed end of the adjusting disc shell and the end face of one end of the mounting frame away from the arc-shaped sliding groove are slidably arranged.

[0027] In this way, the adjusting structure is conveniently protected, and the stability of the mounting frame is ensured.

[0028] When the angle scale lines are arranged on the adjusting disc, the shell is made of transparent material.

[0029] Further, the number of the arc-shaped sliding grooves, the corresponding mounting frames and the leaf springs is a double number greater than 6, and the outer ends of the leaf springs are crimped above or below the corresponding rollers alternately.

[0030] In this way, the leaf springs can keep the adjusting disc and the fixed disc connected by crimping. Compared with the structure of using a pair of rollers to press the leaf springs in the middle, this structure is simpler, and the adjacent leaf springs are respectively given an initial bending deformation upward and downward. In this way, the leaf springs are increased with a pre-tightening force in two directions. In the initial state, the overall balance can be maintained due to the pre-tightening force of the adjacent leaf springs in opposite directions, but due to the pre-tightening force, the force of the adjusted leaf springs becomes larger when the mounting frame slides the same angle distance, which realizes a larger stiffness adjustment effect in the same adjustment space and improves the sensitivity of stiffness adjustment.

[0031] In summary, the device has the advantages of compact and light structure, less interference to the perspective image, high dynamic degree, multi-degree-of-freedom adjustment and simple and compact structure, which can better meet the stiffness adjustment requirements of the support. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 It is a structural schematic diagram of the present application.

[0033] Figure 2 It is a structural schematic diagram of the present application. Figure 1 It is a partial structural schematic diagram of the single screw part.

[0034] Figure 3 It is a partial structural schematic diagram of the single screw part. Figure 1 It is a sectional view of the single support arm.

[0035] Figure 4 It is a sectional view of the single support arm. Figure 1 It is a sectional view of the single variable stiffness adjustment joint part.

[0036] Figure 5 It is a sectional view of the single variable stiffness adjustment joint part. Figure 1 It is a sectional view of the single variable stiffness adjustment joint part. DETAILED DESCRIPTION

[0037] The present application will be further described in detail below in combination with specific embodiments.

[0038] In specific implementation: see Figures 1-5As shown, a three-branch orthopedic external fixation support includes two oppositely arranged fixing rings 1, three support arms 2 are evenly and connectively arranged between the two fixing rings, and a self-expansion adjusting mechanism is arranged on the support arm 2, wherein one end of the support arm is connected to one of the fixing rings through a hinge 3, the other end is directly connected to a nut 4, the axis of the nut 4 is perpendicular to the support arm, the nut 4 is sleeved on a lead screw 5 rotatably arranged on the other fixing ring, one end of the lead screw 5 is provided with a lead screw drive motor 6, and the nut 4 is arranged away from the fixing ring where the lead screw is installed.

[0039] Thus, the structure of the present application is a three-branch structure, which reduces the weight and the interference with the perspective image compared with the conventional six-branch fixation support. Meanwhile, compared with the existing three-branch fixation support of CN201810253067.4, the present application increases the lead screw drive motor, which can realize the rotation control of the lead screw without manual adjustment, thereby improving the automation degree. Meanwhile, in the present application, the nut is directly connected to the support arm, which reduces the setting of one hinge structure, and the structure is more simple and compact. Meanwhile, in the present application, the rotation of the nut in the translation control is directly restricted by the support arm, and the fixing ring where the lead screw is installed does not need to be provided with a guide rail structure matched with the nut, thereby reducing the processing difficulty. Through computer simulation test, since the rotation of the lead screw and the expansion of the support arm are controllable, the nut can realize translation under the simultaneous control of the two, and can also realize the function of multi-degree-of-freedom adjustment.

[0040] Wherein, one end of the support arm 2 is connected to the corresponding fixing ring through a U-shaped hinge. Thus, the control of the self-expansion of the support arm is more convenient.

[0041] Wherein, the U-shaped hinge is installed on the mounting protrusion 7 arranged along the ring periphery of the corresponding fixing ring. Thus, the installation is more convenient, and the weight of the device is reduced.

[0042] Wherein, the lead screw 5 is installed on a U-shaped lead screw seat 8, and the lead screw seat is installed between the mounting protrusions arranged along the ring periphery of the corresponding fixing ring.

[0043] Thus, the installation is more convenient, and the weight of the device is reduced.

[0044] Wherein, the fixing ring 1 is provided with a plurality of through holes. Thus, the installation of the Kirschner needle is convenient, and the weight of the device is reduced.

[0045] Wherein, the support arm includes two sections abutting each other, and the self-expansion adjusting mechanism includes a telescopic motor 9 coaxially installed at the abutting end of one section of the support arm, the telescopic motor 9 has a threaded main shaft 10 coaxial with the support arm, and the threaded main shaft 10 is screwed into a threaded hole coaxially arranged at the abutting end of the other section of the support arm.

[0046] In this way, the telescopic motor rotates to drive the threaded main shaft to rotate along the screw hole, thereby realizing telescopic adjustment.

[0047] The support arm 1 is further provided with a pressure sensor (not shown in the figure) for detecting the axial pressure of the support arm. In this way, the pressure of the support arm can be better detected for feedback control.

[0048] The support arm 1 is further provided with a variable stiffness adjustment joint coaxially mounted thereon.

[0049] In this way, the stiffness of the support arm can be conveniently adjusted to meet the stiffness requirements of the device under different rehabilitation conditions.

[0050] The variable stiffness adjustment joint comprises a fixed disc 11 fixedly arranged relative to the support arm and an adjustment disc 12 rotatably arranged relative to the support arm. The fixed disc 11 and the adjustment disc 12 are annular and coaxially arranged with the support arm. The fixed disc and the adjustment disc each have an opposite mounting end face. The mounting end face of the adjustment disc is uniformly provided with a plurality of arc-shaped sliding grooves along the annular shape. One end of each arc-shaped sliding groove gradually approaches the shaft center in a spiral shape. Each arc-shaped sliding groove is correspondingly provided with a mounting rack 13 of a frame structure. One end of the mounting rack extends outward to form a sliding block slidingly fitted in the arc-shaped sliding groove. A roller 14 is transversely arranged in the inner frame of the mounting rack 13. A plurality of leaf springs 15 are provided on the mounting end face of the fixed disc corresponding to the mounting rack. The inner end of the leaf spring 15 is fixedly mounted at the shaft center of the mounting end face of the fixed disc 11. The outer end of the leaf spring is press-bonded to the roller in the mounting rack.

[0051] In this way, the fixed disc and the adjustment disc are actually connected by the leaf spring. When the stiffness needs to be changed, the adjustment disc is only rotated to change the position of the sliding block of the mounting rack in the arc-shaped sliding groove, so as to change the distance of the mounting rack from the shaft center, and further change the length and spring force of the leaf spring, thereby realizing the adjustment of the stiffness. The structure is simple, and the stiffness adjustment is reliable.

[0052] The outer peripheral surface of the adjustment disc 12 or the fixed disc 11 is further provided with an angle scale.

[0053] In this way, the size of the angle adjustment amount can be conveniently observed and determined, and the control is facilitated.

[0054] One end of the fixed disc 11 is a connecting end connected to the support arm body, and the other end is outwardly convex in the middle. The mounting end face is formed on the end face of the outwardly convex part and the leaf spring is mounted thereon.

[0055] In this way, the fixed disc and the support arm are conveniently connected.

[0056] The adjustment disc 12 is further fixedly provided with a cylindrical adjustment disc shell 16. One end of the adjustment disc shell is used to connect to the support arm body. In this way, the installation and connection of the adjustment disc are better facilitated.

[0057] Another end of the adjusting disc shell 16 extends inward to form a closed end and enclose the mounting frame away from one end of the arc-shaped sliding groove, and the inner side of the closed end of the adjusting disc shell and the end face of the mounting frame away from one end of the arc-shaped sliding groove are slidably arranged.

[0058] In this way, the adjusting structure is conveniently protected, and the stability of the mounting frame is ensured.

[0059] In implementation, when the angle scale is arranged on the adjusting disc, the shell is made of transparent material.

[0060] The number of the arc-shaped sliding grooves, the corresponding mounting frames and the leaf springs is an even number greater than 6, and the outer ends of the leaf springs are alternately crimped above or below the corresponding rollers.

[0061] In this way, the leaf springs can be connected to the adjusting disc and the fixing disc by crimping. Compared with the structure in which a pair of rollers are used to press the leaf springs in the middle in the mounting frame, the structure is simpler, and the adjacent leaf springs are respectively given an initial bending deformation in the upward and downward directions. In this way, the leaf springs are increased with a pre-tightening force in two directions. In the initial state, the adjacent leaf springs are balanced due to the pre-tightening force in the opposite directions. However, due to the pre-tightening force, the force of the adjusted leaf springs becomes larger when the mounting frame slides the same angle distance, so that a larger stiffness adjustment effect is achieved in the same adjustment space, and the sensitivity of the stiffness adjustment is improved.

Claims

1. A three-branch orthopedic external fixation support, comprising two oppositely arranged fixing rings, three support arms are evenly and connectively arranged between the two fixing rings, and a self-expanding adjusting mechanism is arranged on the support arms, characterized in that, One end of the support arm is connected to a fixed ring through a hinge, and the other end is directly connected to a nut which is arranged perpendicularly to the support arm, the nut is sleeved on a screw rod which is rotatably arranged in another fixed ring, one end of the screw rod is connected to a screw rod driving motor, and the end face of the nut away from the support arm is arranged separately from the fixed ring where the screw rod is installed; A variable stiffness adjusting joint is coaxially arranged on the support arm; The variable stiffness adjusting joint comprises a fixed disc which is fixedly arranged relative to the support arm and an adjusting disc which is rotatably arranged relative to the support arm, the fixed disc and the adjusting disc are annular and coaxially arranged with the support arm, each of the fixed disc and the adjusting disc has an opposite mounting end face, a plurality of arc-shaped sliding grooves are uniformly distributed on the mounting end face of the adjusting disc along the annular surface, one end of each arc-shaped sliding groove gradually approaches the axis in a spiral shape, each arc-shaped sliding groove is correspondingly provided with a frame structure mounting bracket, one end of the mounting bracket extends outward to form a sliding block which is slidably arranged in the arc-shaped sliding groove, a roller is transversely arranged in the inner frame of the mounting bracket, a plurality of leaf springs are arranged on the mounting end face of the fixed disc corresponding to the mounting bracket, the inner end of each leaf spring is fixedly arranged at the axis of the mounting end face of the fixed disc, and the outer end of each leaf spring is press-bonded to the roller in the mounting bracket; An adjusting disc shell which is in the shape of a cylinder is further fixedly arranged outside the adjusting disc, one end of the adjusting disc shell is used for being connected to the support arm body; The other end of the adjusting disc shell extends inward to form a closed end and surrounds one end of the mounting bracket away from the arc-shaped sliding groove, and the inner side of the closed end of the adjusting disc shell and the end face of the mounting bracket away from the arc-shaped sliding groove are slidably arranged. The number of the arc-shaped sliding grooves, the corresponding mounting brackets and the leaf springs is a double number greater than 6, and the outer ends of the leaf springs are press-bonded above or below the corresponding rollers in an up-and-down staggered manner.

2. The three-pronged orthopaedic external fixation frame of claim 1, wherein, One end of the support arm is connected to a corresponding fixed ring through a U-shaped hinge. The U-shaped hinge is installed on the mounting protrusions which are uniformly arranged along the annular surface of the corresponding fixed ring.

3. The three-pronged orthopaedic external fixation frame of claim 1, wherein, The screw rod is installed on a U-shaped screw rod seat which is installed between the mounting protrusions which are uniformly arranged along the annular surface of the corresponding fixed ring.

4. The three-pronged orthopaedic external fixation frame of claim 1, wherein, The fixed ring is provided with a plurality of through holes.

5. The three-pronged orthopaedic external fixation frame of claim 1, wherein, The support arm comprises two sections which are abutted to each other, the self-elongating adjusting mechanism comprises an elongating motor which is coaxially installed on the abutted end of one section of the support arm, the elongating motor has a threaded main shaft which is coaxial with the support arm, and the threaded main shaft is screwed into a screw hole which is coaxially arranged on the abutted end of the other section of the support arm.

6. The three-pronged orthopaedic external fixation frame of claim 1, wherein, A pressure sensor for detecting the axial pressure of the support arm is further arranged on the support arm.

7. The three-pronged orthopaedic external fixation frame of claim 1, wherein, An angle scale is further arranged on the outer surface of the adjusting disc or the fixed disc. One end of the fixed disc is a connecting end which is connected to the support arm body, the other end is outwardly convex in the middle, and the end face of the outwardly convex part forms the mounting end face and the leaf springs are installed on the mounting end face.

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