Knee joint internal distraction device

Abstract

The invention discloses a knee joint internal distraction device, relates to the field of wound tractors, and solves the problems that when an existing knee joint internal distraction device is used, the distraction position is not clearly observed, the distraction area is relatively fixed, and tearing and discomfort are prone to occurring, the knee joint internal distraction device comprises a mounting ring, a sliding frame and a distraction mechanism, the expanding mechanism comprises a first expanding plate, a second expanding plate, a third expanding plate, a sliding part and an adjusting part, the adjusting part on the expanding mechanism controls the overturning state of the first expanding plate, and the first expanding plate in the expanding state slides towards the periphery to be expanded; the second distraction plate and the third distraction plate are sequentially linked to turn over to the two sides of the first distraction plate, the supporting area is gradually increased along with the expansion of the distraction degree, the supporting stability and comfort are improved, meanwhile, the first distraction plate in the non-distraction state can keep moving synchronously, and the second distraction plate and the third distraction plate are not linked to turn over, so that the supporting effect is improved. And the view at the opening position is not shielded.

Description

Technical Field

[0001] The present invention relates to the technical field of wound traction devices, and particularly to an internal knee joint spreading device. Background Art

[0002] Arthroscopy is a standard orthopedic technique. Doctors can use arthroscopes and special minimally invasive surgical instruments to make some surgeries minimally invasive. Many joints such as the knee, hip, shoulder, ankle, elbow, and wrist can use arthroscopes. Currently, knee arthroscopes are used the most and have the widest indications. In knee arthroscopic surgery, it is necessary to fully expose the diseased parts inside the knee joint so that doctors can clearly observe and perform surgical operations.

[0003] Existing internal knee joint spreading devices mostly adopt a method of supporting from the middle to the surrounding during use. For example, the related spreading devices disclosed in publication numbers CN109464171A and CN117379124A. These structures can only play a role in supporting the wound, but at this time, the doctor's field of vision is also blocked to a large extent. The middle wound at the spreading position is blocked by the device body, seriously affecting the subsequent operations of medical staff and being unfavorable for the progress of the surgery. At the same time, the supporting area of these devices is relatively fixed, and it is difficult to automatically adjust the area that the supporting position fits according to the size of the required spreading range. When always using a support plate with a small area for support, if the spreading range is too large, it is easy to cause wound tearing or local discomfort. Summary of the Invention

[0004] The purpose of the present invention is to provide an internal knee joint spreading device that is convenient for improving the stability during the spreading process and does not block the spreading position, so as to solve the problems raised in the above background art.

[0005] To achieve the above purpose, the present invention provides the following technical solution: An internal knee joint spreading device, including an installation ring and a spreading mechanism. A plurality of sliding frames are evenly and slidably connected to the installation ring. The spreading mechanism includes a first spreading plate installed on the sliding frame. There are two groups of second spreading plates and two groups of third spreading plates on the sliding frame. A sliding member for driving the plurality of sliding frames to slide synchronously towards the surrounding is provided on the installation ring. An adjusting member for adjusting the flipping state of the first spreading plate is provided on the sliding frame. The spreading mechanism can adjust the flipping state of the first spreading plate through the adjusting member, and when the first spreading plate in the spreading state slides towards the surrounding to spread, it sequentially drives the second spreading plate and the third spreading plate to flip to both sides of the first spreading plate, gradually increasing the supporting area as the spreading degree expands, improving the stability and comfort of the support, and being convenient for improving the stability during the spreading process and not blocking the spreading position.

[0006] Preferably, the spreading mechanism further includes a sliding rod installed on the sliding frame. A sliding groove is formed in the sliding frame and is slidably connected to the outer wall of the sliding rod in the horizontal direction. One end of the sliding rod is fixedly connected to a fixed rod, and the bottom of the fixed rod is fixedly connected to a rotating frame. The first spreading plate is rotatably connected to the rotating frame. A control member for controlling the rotating states of the second spreading plate and the third spreading plate is provided on the sliding frame, which is convenient for improving the stability and comfort of the support.

[0007] Preferably, the control member includes two sets of moving frames slidably connected to the inner wall of the sliding groove in the horizontal direction. One end of the moving frame is fixedly connected to a first spring fixedly connected to the sliding frame. Two sets of fixed frames are fixedly connected to the sliding frame. The second spreading plate is rotatably connected to the side of the moving frame, and the third spreading plate is rotatably connected to the side of the fixed frame. Hairspring springs are fixedly connected to both the moving frame and the fixed frame respectively. The second spreading plate and the third spreading plate are respectively fixedly connected to one end of the adjacent hairspring springs. A rotating member for driving the second spreading plate and the third spreading plate to rotate is provided on the sliding rod, which is convenient for controlling the rotating states of the second spreading plate and the third spreading plate.

[0008] Preferably, the rotating member includes a sliding plate installed at the bottom of the sliding rod. A first gear is fixedly connected to the side of the second spreading plate, and a second gear is fixedly connected to the side of the third spreading plate. A lifting groove is formed in the side of the sliding rod. A first rack capable of meshing with the first gear is slidably connected in the lifting groove in the vertical direction. The bottom surface of the first rack is fixedly connected to the top surface of the sliding plate. A second rack capable of meshing with the second gear is provided on the side of the moving frame. The adjusting member can control the lifting state of the sliding plate while adjusting the rotating state of the first spreading plate, which is convenient for driving the second spreading plate and the third spreading plate to rotate.

[0009] Preferably, the adjusting member includes a threaded rod rotatably connected to the top surface of the sliding plate. The threaded rod penetrates through the sliding rod and is threadedly connected to the sliding rod. A bent rod for pushing the first spreading plate to flip and fold is fixedly connected to the sliding plate. A guiding frame for guiding the vertical sliding of the outer wall of the second rack is fixedly connected to the side of the moving frame. A guiding groove is formed in the side of the sliding plate. A guiding block slidably connected to the inner wall of the guiding groove in the horizontal direction is fixedly connected to the bottom of the second rack, which is convenient for adjusting the flipping state of the first spreading plate.

[0010] Preferably, the sliding member includes a second spring fixedly installed at one end of the sliding rod. The end of the second spring away from the sliding rod is fixedly connected to the sliding groove. A third spring fixedly connected to the inner wall of the mounting ring is fixedly connected to the sliding frame. A rotating ring is rotatably connected to the mounting ring. A moving member for driving the sliding frame to move is provided on the rotating ring, which is convenient for driving multiple groups of the sliding frames to slide synchronously in all directions.

[0011] Preferably, the moving member includes a first pulling rope fixedly installed at one end of the sliding rod. A rotating groove is formed at the bottom of the rotating ring. A driving block is fixedly connected in the rotating groove. The first pulling rope penetrates through the mounting ring and is slidably connected to the inner wall of the mounting ring. The end of the first pulling rope away from the sliding rod is fixedly connected to the side surface of the driving block. A driving member for driving the rotating ring to rotate is provided on the mounting ring, which is convenient for driving the sliding frame to move.

[0012] Preferably, the driving member includes a driving shaft rotatably connected to the mounting ring. A bevel gear ring is coaxially and fixedly connected to the bottom of the rotating ring. A first bevel gear meshing with the bevel gear ring is coaxially and fixedly connected to one end of the driving shaft. Multiple groups of helical teeth are uniformly fixedly connected to the outer wall of the driving shaft. A spring catch capable of unidirectionally clamping the helical teeth is provided in the mounting ring. One end of the spring catch is fixedly connected to a second pulling rope, which is convenient for driving the rotating ring to rotate.

[0013] Preferably, multiple groups of straps for fixing the mounting ring to the patient's body are fixedly connected to the mounting ring, which is convenient for fixing the mounting ring to the patient's body.

[0014] Preferably, buffer pads are respectively fixedly connected to the sides of the first spreading plate, the second spreading plate, and the third spreading plate, which is convenient for reducing damage to the spreading position.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: A knee joint internal spreading device provided by the present invention solves the problems that the existing knee joint internal spreading device has unclear observation of the spreading position during use, and the spreading area is relatively fixed, which is prone to tearing and discomfort. By controlling the flipping state of the first spreading plate through the adjusting member on the spreading mechanism, and making the first spreading plate in the spreading state slide and spread in all directions, the second spreading plate and the third spreading plate are successively linked to flip to both sides of the first spreading plate, and the supporting area is gradually increased as the spreading degree expands, improving the stability and comfort of the support. At the same time, the first spreading plate in the non-spreading state will also move synchronously and does not link the flipping of the second spreading plate and the third spreading plate, keeping the field of view at the spreading position unobstructed. Description of the Drawings

[0016] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the bottom structure of the mounting ring of the present invention; Figure 3 for Figure 2 A magnified image of the middle A area; Figure 4 It is a schematic diagram of the local structure of the sliding member of the present invention; Figure 5 for Figure 4 Enlarged view of area B; Figure 6 for Figure 4 Enlarged view of area C in the middle; Figure 7 It is a schematic diagram of the partial structure of the opening mechanism of the present invention; Figure 8 This is a schematic diagram of the supporting state structure of the first open plate of the present invention; Figure 9 for Figure 8 Enlarged view of area D in the middle; Figure 10 This is a schematic diagram of the structure of the first opening plate of the present invention in a flipping state; Figure 11 for Figure 10 Enlarged view of area E in the middle; Figure 12 This is a partial structural sectional view of the opening mechanism of the present invention.

[0017] In the figure: 1-mounting ring; 2-sliding frame; 3-first opening plate; 4-second opening plate; 5-third opening plate; 6-sliding rod; 7-sliding groove; 8-fixed rod; 9-rotating frame; 10-moving frame; 11-first spring; 12-fixed frame; 13-spring spring; 14-sliding plate; 15-first gear; 16-second gear; 17-lifting groove; 18-first rack; 19-second rack; 20-threaded rod; 21-bending rod; 22-guide frame; 23-guide groove; 24-guide block; 25-second spring; 26-third spring; 27-rotating ring; 28-first pull rope; 29-rotating groove; 30-driving block; 32-driving shaft; 33-bevel gear ring; 34-first bevel gear; 35-bevel gear block; 36-spring block; 37-second pull rope; 38-binding strap; 39-buffer pad. DETAILED DESCRIPTION

[0018] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0019] Please refer to Figures 1-12 , the present invention provides a technical solution: an in-knee joint spreading device, which includes an installation ring 1 and a spreading mechanism. A plurality of groups of sliding frames 2 are uniformly and slidably connected to the installation ring 1. A plurality of groups of straps 38 for fixing the installation ring 1 to the patient's body are fixedly connected to the installation ring 1. The spreading mechanism includes a first spreading plate 3 installed on the sliding frame 2. There are two groups of second spreading plates 4 and two groups of third spreading plates 5 on the sliding frame 2. Buffer pads 39 are fixedly connected to the sides of the first spreading plate 3, the second spreading plates 4, and the third spreading plates 5 respectively. A sliding member for driving a plurality of groups of sliding frames 2 to slide synchronously around is provided on the installation ring 1. An adjusting member for adjusting the flipping state of the first spreading plate 3 is provided on the sliding frame 2. The spreading mechanism can adjust the flipping state of the first spreading plate 3 through the adjusting member, and make the first spreading plate 3 in the spreading state drive the second spreading plates 4 and the third spreading plates 5 to flip to both sides of the first spreading plate 3 in the process of sliding and spreading around, and gradually increase the supporting area with the expansion of the spreading degree, so as to improve the stability and comfort of the support.

[0020] The spreading mechanism further includes a sliding rod 6 installed on the sliding frame 2. A sliding groove 7 slidably connected to the outer wall of the sliding rod 6 in the horizontal direction is formed in the sliding frame 2. One end of the sliding rod 6 is fixedly connected to a fixed rod 8. A rotating frame 9 is fixedly connected to the bottom of the fixed rod 8. The first spreading plate 3 is rotatably connected to the rotating frame 9. A control member for controlling the rotating states of the second spreading plates 4 and the third spreading plates 5 is provided on the sliding frame 2.

[0021] The control member includes two groups of moving frames 10 slidably connected to the inner wall of the sliding groove 7 in the horizontal direction. One end of the moving frame 10 is fixedly connected to a first spring 11 fixedly connected to the sliding frame 2. Two groups of fixed frames 12 are fixedly connected to the sliding frame 2. The second spreading plate 4 is rotatably connected to the side of the moving frame 10. The third spreading plate 5 is rotatably connected to the side of the fixed frame 12. Hairspring springs 13 are fixedly connected to the moving frames 10 and the fixed frames 12 respectively. The second spreading plates 4 and the third spreading plates 5 are respectively fixedly connected to one end of the adjacent hairspring springs 13. A rotating member for driving the second spreading plates 4 and the third spreading plates 5 to rotate is provided on the sliding rod 6.

[0022] The rotating member includes a sliding plate 14 installed at the bottom of the sliding rod 6. A first gear 15 is fixedly connected to the side surface of the second spreading plate 4, and a second gear 16 is fixedly connected to the side surface of the third spreading plate 5. A lifting groove 17 is formed in the side surface of the sliding rod 6. A first rack 18 that can mesh with the first gear 15 is slidably connected in the lifting groove 17 along the vertical direction. The bottom surface of the first rack 18 is fixedly connected to the top surface of the sliding plate 14. A second rack 19 that can mesh with the second gear 16 is provided on the side surface of the moving frame 10. The adjusting member can control the lifting state of the sliding plate 14 while adjusting the rotating state of the first spreading plate 3.

[0023] The adjusting member includes a threaded rod 20 rotatably connected to the top surface of the sliding plate 14. The threaded rod 20 penetrates through the sliding rod 6 and is threadedly connected to the sliding rod 6. A bent rod 21 for pushing the first spreading plate 3 to flip and fold is fixedly connected to the sliding plate 14. A guiding frame 22 for guiding the vertical sliding of the outer wall of the second rack 19 is fixedly connected to the side surface of the moving frame 10. A guiding groove 23 is formed in the side surface of the sliding plate 14. A guiding block 24 slidably connected to the inner wall of the guiding groove 23 along the horizontal direction is fixedly connected to the bottom of the second rack 19.

[0024] The sliding member includes a second spring 25 fixedly installed at one end of the sliding rod 6. The end of the second spring 25 away from the sliding rod 6 is fixedly connected to the sliding groove 7. A third spring 26 fixedly connected to the inner wall of the mounting ring 1 is fixedly connected to the sliding frame 2. A rotating ring 27 is rotatably connected to the mounting ring 1. A moving member for driving the sliding frame 2 to move is provided on the rotating ring 27.

[0025] The moving member includes a first pulling rope 28 fixedly installed at one end of the sliding rod 6. A rotating groove 29 is formed in the bottom of the rotating ring 27. A driving block 30 is fixedly connected in the rotating groove 29. The first pulling rope 28 penetrates through the mounting ring 1 and is slidably connected to the inner wall of the mounting ring 1. The end of the first pulling rope 28 away from the sliding rod 6 is fixedly connected to the side surface of the driving block 30. A driving member for driving the rotating ring 27 to rotate is provided on the mounting ring 1.

[0026] The driving member includes a driving shaft 32 rotatably connected to the mounting ring 1. A bevel gear ring 33 is coaxially fixedly connected to the bottom of the rotating ring 27. A first bevel gear 34 meshing with the bevel gear ring 33 is coaxially fixedly connected to one end of the driving shaft 32. A plurality of groups of helical teeth 35 are evenly fixedly connected to the outer wall of the driving shaft 32. A spring catch 36 for unidirectionally clamping the helical teeth 35 is provided in the mounting ring 1. One end of the spring catch 36 is fixedly connected to a second pulling rope 37.

[0027] In this embodiment, the mounting ring 1 is fixed at the position on the patient's leg that needs to be expanded by the strap 38. By rotating the threaded rod 20, the sliding plate 14 is driven to move up and down. When the sliding plate 14 moves down, the first rack 18 is driven to move down. At the same time, the first expansion plate 3 is pushed by the bending rod 21 to rotate around the rotating frame 9 to a position close to the bottom surface of the sliding plate 14, so that the first expansion plate 3 at this position can be adjusted to a folded state. This device can flexibly adjust the number of first expansion plates 3 to be used. For example, when only spreading to both sides is required, only two sets of oppositely arranged first expansion plates 3 need to move and expand, and the remaining first expansion plates 3 do not need to be expanded to avoid expanding unnecessary areas and affecting the operation. At the same time, the sliding plate 14 drives the guide block 24 and the second rack 19 to move down through the guide groove 23, while the threaded rod 20 is not rotated on the sliding rod 6 that needs to be expanded, and the bending rod 21 does not push the first expansion plate 3 to flip, so that the first expansion plate 3 at this position can be kept in a straight line with the fixed rod 8 under the drive of the spring winding shaft of the rotating block, which is convenient for subsequent expansion operations. After that, the driving shaft 32 is rotated to drive the first bevel gear 34 to rotate. The first bevel gear 34 drives the bevel gear ring 33 to rotate, so that the rotating ring 27 drives the driving block 30 to pull the first pull rope 28. The first pull rope 28 pulls one end of the sliding rod 6 to gradually compress the second spring 25. During the horizontal sliding of the sliding rod 6 in the sliding groove 7, the fixed rod 8 and the first expansion plate 3 can be driven to move. Multiple first expansion plates 3 can be synchronously expanded around in all directions under the drive of the first pull rope 28. Due to the push of the third spring 26, the stability of the sliding frame 2 will be maintained first. During the sliding of the sliding rod 6 in the sliding groove 7, only the first expansion plate 3 with a vertical bottom is used to expand the required position. An observation opening without occlusion is formed between the positions of multiple first expansion plates 3, which is convenient for observing the expanded position and performing the operation.

[0028] During the synchronous sliding of the sliding rod 6 and the first spreading plate 3, the sliding plate 14 will also slide accordingly, causing the first rack 18 to gradually approach the bottom of the first gear 15. When the first spreading plate 3 is in the spreading state, the sliding plate 14 at this position is not pushed down by the threaded rod 20, so that the heights of the first rack 18 and the second rack 19 can just mesh with the first gear 15 and the second gear 16. When the sliding rod 6 drives the first rack 18 past the first gear 15, it can drive the first gear 15 to flip 180° with the second spreading plate 4. The second spreading plates 4 on both sides are simultaneously flipped to both sides of the first spreading plate 3 to provide auxiliary support for the part to be spread, increasing the support area, reducing the risk of tearing and discomfort. Then the sliding plate 14 continues to slide, and the second rack 19 will gradually drive the second gear 16 to rotate, so that the third spreading plate 5 rotates 180°. The third spreading plates 5 on both sides synchronously reach both sides of the second spreading plate 4 for auxiliary support, further expanding the support area. After that, the sliding rod 6 continues to slide. Since the fixed rod 8 has already abutted against one end of the sliding frame 2, it can directly drive the sliding frame 2 to slide and open around, and the third spring 26 is compressed.

[0029] At the position where the first spreading plate 3 is in the flipped state, the sliding plate 14 is in the downward movement state, and the first rack 18 and the second rack 19 move downward relatively. So that during the movement of the sliding rod 6, the first rack 18 and the second rack 19 cannot mesh with the corresponding first gear 15 and second gear 16 at the corresponding positions. This can ensure that the first spreading plate 3, the second spreading plate 4, and the third spreading plate 5 are all in the initial state during the entire opening process, and will not flip downward to spread the wound. At the same time, it also ensures that these first spreading plates 3, second spreading plates 4, and third spreading plates 5 can open synchronously, ensuring the clarity of the observation field of view, avoiding affecting the surgical operation, and making the use more convenient and efficient.

[0030] During the rotation of the drive shaft 32, the spring catch 36 will continuously perform one-way limit clamping on the helical block 35. After spreading to the required position, directly releasing the drive shaft 32 can perform automatic limiting. When it is necessary to reset the sliding frame 2, the second pull rope 37 is pulled to release the clamping of the spring catch 36 on the helical block 35, and reverse rotation of the drive shaft 32 can drive the rotating ring 27 to rotate in the reverse direction, reducing the pulling force on the first pull rope 28. Then, under the combined action of the first spring 11, the second spring 25, and the third spring 26, the sliding rod 6 and the moving frame 10 can be pushed to slide back to their original positions. The elastic forces of the first spring 11 and the second spring 25 are much smaller than the elastic force of the third spring 26.

[0031] It should be noted that in this text, relational terms such as first and second are only used 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 term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device.

[0032] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An intra-articular knee joint distraction device, characterized in that, include: A mounting ring (1), wherein a plurality of sets of sliding frames (2) are uniformly and slidably connected to the mounting ring (1); Also includes: The expansion mechanism comprises a first expansion plate (3) mounted on the sliding frame (2), the sliding frame (2) being provided with two groups of second expansion plates (4) and two groups of third expansion plates (5), the mounting ring (1) being provided with a sliding member for driving the plurality of groups of the sliding frames (2) to slide synchronously in all directions, the sliding frame (2) being provided with an adjusting member for adjusting the flipping state of the first expansion plate (3), the expansion mechanism being able to adjust the flipping state of the first expansion plate (3) through the adjusting member, and enabling the first expansion plate (3) in the expanded state to slide in all directions and expand in the process of being sequentially linked with the second expansion plate (4) and the third expansion plate (5) to flip to the two sides of the first expansion plate (3), so that the support area is gradually increased as the expansion degree increases, thereby improving the stability and comfort of the support.

2. The knee joint internal expansion device according to claim 1, wherein: The spreading mechanism further comprises a sliding rod (6) mounted on the sliding frame (2); a sliding groove (7) is provided in the sliding frame (2) and is slidably connected to the outer wall of the sliding rod (6) in a horizontal direction; one end of the sliding rod (6) is fixedly connected to a fixing rod (8); the bottom of the fixing rod (8) is fixedly connected to a rotating frame (9); the first spreading plate (3) is rotatably connected to the rotating frame (9); and a control member for controlling the rotation state of the second spreading plate (4) and the third spreading plate (5) is provided on the sliding frame (2).

3. The knee joint internal expansion device according to claim 2, characterized in that: The control member comprises two groups of movable frames (10) slidably connected to the inner wall of the sliding groove (7) in the horizontal direction; one end of the movable frame (10) is fixedly connected to a first spring (11) fixedly connected to the sliding frame (2); two groups of fixed frames (12) are fixedly connected to the sliding frame (2); the second opening plate (4) is rotatably connected to the side of the movable frame (10); the third opening plate (5) is rotatably connected to the side of the fixed frame (12); the movable frame (10) and the fixed frame (12) are respectively fixedly connected to a clockwork spring (13); the second opening plate (4) and the third opening plate (5) are respectively fixedly connected to one end of an adjacent clockwork spring (13); and a rotating member for driving the second opening plate (4) and the third opening plate (5) to rotate is provided on the sliding rod (6).

4. The knee joint internal expansion device according to claim 3, characterized in that: The rotating member includes a sliding plate (14) installed at the bottom of the sliding rod (6). A first gear (15) is fixedly connected to the side of the second spreading plate (4), and a second gear (16) is fixedly connected to the side of the third spreading plate (5). A lifting groove (17) is formed in the side of the sliding rod (6). A first rack (18) capable of meshing with the first gear (15) is slidably connected in the lifting groove (17) in the vertical direction. The bottom surface of the first rack (18) is fixedly connected to the top surface of the sliding plate (14). A second rack (19) capable of meshing with the second gear (16) is provided on the side of the moving frame (10). The adjusting member can control the lifting state of the sliding plate (14) while adjusting the rotating state of the first spreading plate (3).

5. The knee joint internal expansion device according to claim 4, characterized in that: The adjusting member includes a threaded rod (20) rotatably connected to the top surface of the sliding plate (14). The threaded rod (20) penetrates through the sliding rod (6) and is threadedly connected to the sliding rod (6). A bent rod (21) for pushing the first spreading plate (3) to turn and fold is fixedly connected to the sliding plate (14). A guide frame (22) for guiding the outer wall of the second rack (19) to slide in the vertical direction is fixedly connected to the side of the moving frame (10). A guide groove (23) is formed in the side of the sliding plate (14). A guide block (24) slidably connected to the inner wall of the guide groove (23) in the horizontal direction is fixedly connected to the bottom of the second rack (19).

6. The knee joint internal expansion device according to claim 2, characterized in that: The sliding member includes a second spring (25) fixedly installed at one end of the sliding rod (6). The end of the second spring (25) away from the sliding rod (6) is fixedly connected to the sliding groove (7). A third spring (26) fixedly connected to the inner wall of the mounting ring (1) is fixedly connected to the sliding frame (2). A rotating ring (27) is rotatably connected to the mounting ring (1). A moving member for driving the sliding frame (2) to move is provided on the rotating ring (27).

7. A knee joint internal distraction device according to claim 6, characterized in that: The moving member includes a first pulling rope (28) fixedly installed at one end of the sliding rod (6). A rotating groove (29) is formed in the bottom of the rotating ring (27). A driving block (30) is fixedly connected in the rotating groove (29). The first pulling rope (28) penetrates through the mounting ring (1) and is slidably connected to the inner wall of the mounting ring (1). The end of the first pulling rope (28) away from the sliding rod (6) is fixedly connected to the side of the driving block (30). A driving member for driving the rotating ring (27) to rotate is provided on the mounting ring (1).

8. The knee joint internal expansion device according to claim 7, wherein: The driving member includes a driving shaft (32) rotatably connected to the mounting ring (1). A bevel gear ring (33) is coaxially and fixedly connected to the bottom of the rotating ring (27). One end of the driving shaft (32) is coaxially and fixedly connected with a first bevel gear (34) meshing with the bevel gear ring (33). A plurality of groups of helical teeth (35) are uniformly and fixedly connected to the outer wall of the driving shaft (32). A spring catch (36) capable of unidirectionally clamping the helical teeth (35) is arranged in the mounting ring (1). One end of the spring catch (36) is fixedly connected with a second pulling rope (37).

9. The knee joint internal distraction device according to claim 1, characterized in that: A plurality of groups of straps (38) for fixing the mounting ring (1) to the patient's body are fixedly connected to the mounting ring (1).

10. The knee joint internal distraction device according to claim 1, characterized in that: Buffer pads (39) are respectively and fixedly connected to the sides of the first spreading plate (3), the second spreading plate (4) and the third spreading plate (5).

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