Knee joint prosthesis

Abstract

The invention provides a knee joint prosthesis which comprises a tibial plateau prosthesis, a tibial spacer prosthesis, a femoral condyle prosthesis and an extension rod device, the extension rod device comprises a rod body and a rod sleeve, the rod body and the rod sleeve are arranged in an embedded mode, the rod body is movably arranged on the rod sleeve in the axial direction of the rod sleeve, and a plurality of limiting grooves are formed in the rod body; the limiting structure is movably arranged on the rod sleeve in the circumferential direction of the rod sleeve, the limiting structure is provided with a limiting position and a separating position, when the limiting structure is located at the limiting position, the limiting structure is located in one limiting groove and matched with the limiting groove in a limiting mode, the rod sleeve and the rod body are kept relatively static, and when the limiting structure is located at the separating position, the limiting structure is located in the other limiting groove and matched with the limiting groove in a limiting mode. When the limiting structure is separated from the limiting groove, the rod body can move relative to the rod sleeve; the first reset structure applies reset force to the limiting structure so that the limiting structure can be kept at the limiting position. According to the technical scheme, the problem that in the prior art, after the length of an extension rod device is adjusted, the stability of the extension rod device is poor is effectively solved.

Description

Technical Field

[0001] This invention relates to the field of prosthesis technology, and more specifically, to a knee joint prosthesis. Background Technology

[0002] In medical practice, various factors such as birth defects, accidental injuries, tissue removal after cancer treatment, infections, and chronic diseases often cause severe knee joint dysfunction or lower limb length mismatch in patients. To address these conditions, knee replacement surgery can be performed to restore mobility. However, even after knee prosthesis implantation, lower limb length mismatch may still occur. Therefore, knee prostheses capable of length adjustment are necessary.

[0003] In the existing technology, knee joint prostheses that can achieve length adjustment are generally achieved by adjusting the length of the intramedullary rod. The intramedullary rod generally includes a first column and a second column connected by threads. By rotating the first column relative to the second column, the length between the first column and the second column can be adjusted. However, after the length between the first column and the second column is adjusted, the relative position between the first column and the second column is fixed only by the threads. Summary of the Invention

[0004] The main objective of this invention is to provide a knee joint prosthesis that solves the problem of poor stability of the extension rod device after its length is adjusted in related technologies.

[0005] To achieve the above objectives, the present invention provides a knee joint prosthesis, comprising: a tibial plateau prosthesis, a tibial spacer prosthesis, a femoral condyle prosthesis, and an extension rod device. The tibial spacer prosthesis is disposed above the tibial plateau prosthesis, the femoral condyle prosthesis is adjustablely disposed on the tibial spacer prosthesis, and the extension rod device is disposed at the bottom of the tibial plateau prosthesis or the top of the femoral condyle prosthesis. The extension rod device includes: a rod sleeve; a rod body, nested within the rod sleeve and movably disposed on the rod sleeve along the axial direction of the rod sleeve, the rod body having multiple limiting grooves; and limiting... The structure is movably mounted on the sleeve along its circumferential direction. The limiting structure is configured to have a limiting position and a disengaged position under the control of an external tool. When the limiting structure is in the limiting position, it is located in one of the limiting grooves and engages with the groove to keep the sleeve and the rod relatively stationary. When the limiting structure is in the disengaged position, it separates from the groove to allow the rod to move relative to the sleeve. A first reset structure applies a reset force to the limiting structure to keep it in the limiting position.

[0006] Furthermore, the limiting structure includes a limiting ball, and the inner wall of the sleeve is provided with a first arc-shaped groove extending along the circumferential direction of the sleeve, and the limiting ball is slidably disposed in the first arc-shaped groove.

[0007] Furthermore, the first reset structure includes an elastic element and / or an adsorption element, wherein the elastic element is disposed within the first arc-shaped groove and located between the rod sleeve and the limiting ball, and the adsorption element is disposed on the inner wall of the rod sleeve.

[0008] Furthermore, the extension rod device also includes an anti-rotation structure extending along the axial direction of the rod sleeve. The anti-rotation structure includes a guide groove and a guide rod. The guide groove and the guide rod are guided and engaged. One of the guide groove and the guide rod is disposed on the inner wall of the rod sleeve, and the other of the guide groove and the guide rod is disposed on the outer wall of the rod body.

[0009] Furthermore, the first end of the rod is inserted into the sleeve, and the second end of the rod is located outside the rod. The extension rod device also includes a one-way stop structure, which is disposed between the sleeve and the rod to restrict the movement of the rod along the direction from the second end to the first end of the rod.

[0010] Furthermore, the one-way stop structure includes a stop plate, a second reset member, and multiple stop teeth. The stop plate is oscillatingly disposed and engages with one of the stop teeth for limiting. One of the stop plate and the stop teeth is disposed on the outer wall of the rod body, and the other of the stop plate and the stop teeth is disposed on the inner wall of the rod sleeve. The second reset member is disposed between the stop plate and the rod sleeve or the rod body.

[0011] Furthermore, the extension rod device also includes a transmission mechanism, the first end of which engages with a limiting ball, and the second end of which engages with a rod drive to enable the rod to move.

[0012] Furthermore, the sleeve is provided with an arc-shaped guide hole and a radial mounting hole communicating with the arc-shaped guide hole. The transmission mechanism includes an arc-shaped transmission rod and a gear set. The arc-shaped transmission rod is movably disposed in the arc-shaped guide hole, and the gear set is disposed in the radial mounting hole. The first end of the arc-shaped transmission rod is connected to a limiting ball, and the second end of the arc-shaped transmission rod is driven by the gear set. The gear set is driven by the rod body so that the rod body can move.

[0013] Furthermore, the gear set includes a first transmission wheel, a second transmission wheel, and a connecting rod. The arc-shaped transmission rod is driven by the first transmission wheel, and the second transmission wheel is driven by the rod body. The first transmission wheel is rotatably mounted on the connecting rod, and the second transmission wheel is fixedly connected to the connecting rod. The connecting rod is rotatably mounted on the rod sleeve. When the first transmission wheel rotates along a first preset direction, the first transmission wheel can drive the connecting rod to rotate. When the first transmission wheel rotates along a second preset direction opposite to the first preset direction, the first transmission wheel can rotate relative to the second transmission wheel while the second transmission wheel remains stationary.

[0014] Furthermore, the arc-shaped transmission rod has a first transmission tooth portion that meshes with a first transmission wheel, and / or, a protrusion is provided on the outer wall of the rod body, and a second transmission tooth portion is provided on the protrusion, with the second transmission wheel meshing with the second transmission tooth portion.

[0015] According to the technical solution of this invention, a knee joint prosthesis includes a tibial plateau prosthesis, a tibial spacer prosthesis, a femoral condyle prosthesis, and an extension rod device. The extension rod device includes a sleeve, a rod body, a limiting structure, and a first reduction structure. The tibial plateau prosthesis supports the tibial spacer prosthesis, and the tibial spacer prosthesis supports the femoral condyle prosthesis. The rod body can move axially along the sleeve, thereby adjusting the relative position between the rod body and the sleeve, and thus adjusting the length of the extension rod device. An external tool can control the limiting structure to move circumferentially along the sleeve, allowing the limiting structure to switch between a limited position and a separated position. When the limiting structure is in the limited position, it is located within one of multiple limiting grooves, and it engages with the rod body, ensuring that the relative position between the rod body and the sleeve remains unchanged, thus improving the stability of the extension rod device. When the limiting structure is in the separated position, it separates from the limiting groove, i.e., the limiting structure avoids the rod body, allowing the rod body to move relative to the sleeve. The first repositioning structure can apply a repositioning force to the limiting structure, keeping the limiting structure in its limited position. The tibial plateau prosthesis or femoral condyle prosthesis can be connected to the bone structure via an extension rod device. Therefore, the technical solution of this application effectively solves the problem of poor stability of the extension rod device after its length is adjusted in related technologies. Attached Figure Description

[0016] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 A three-dimensional structural schematic diagram of an embodiment of a knee joint prosthesis according to the present invention is shown; Figure 2 It shows Figure 1 A three-dimensional structural diagram of the connection between the extension rod device of the knee joint prosthesis and the tibial plateau; Figure 3 It shows Figure 1 A three-dimensional structural diagram of the extension rod device for a knee joint prosthesis; Figure 4 It shows Figure 3 A cross-sectional schematic diagram of the extension rod device; Figure 5 It shows Figure 4 A three-dimensional structural diagram of the extension rod device from another perspective; Figure 6 It shows Figure 5 A partially enlarged schematic diagram of point A of the extension rod device; Figure 7 It shows Figure 3 A three-dimensional structural diagram of the extension rod device, including the rod body, limiting structure, first reset structure, and transmission mechanism; Figure 8 It shows Figure 7 A partially enlarged schematic diagram of point B of the extension rod device; Figure 9 It shows Figure 7 A partially enlarged schematic diagram of point C of the extension rod device; Figure 10 It shows Figure 3 A three-dimensional structural diagram of the extension rod device; Figure 11 It shows Figure 3 A cross-sectional schematic diagram of the first position of the extension rod sleeve; Figure 12 It shows Figure 3 A cross-sectional schematic diagram of the second position of the extension rod sleeve; Figure 13 It shows Figure 3 An exploded view of the first drive wheel, the second drive wheel, and the connecting rod of the extension rod device; Figure 14 It shows Figure 3 Front view of the first drive wheel of the extension rod device; Figure 15 It shows Figure 3 A cross-sectional view of the one-way transmission structure of the extension rod device in the avoidance state; Figure 16 It shows Figure 3 A cross-sectional view of the unidirectional transmission structure of the extension rod device in the transmission state.

[0017] The above figures include the following reference numerals: 1. Tibial plateau prosthesis; 2. Tibial spacer prosthesis; 3. Femoral condyle prosthesis; 10. Rod sleeve; 11. First arc-shaped groove; 12. Arc-shaped guide hole; 13. Radial mounting hole; 14. First mounting space; 15. Second mounting space; 16. First receiving groove; 17. Third mounting space; 20. Rod body; 21. Limiting groove; 22. Convex plate; 23. Rod body; 24. Plate body; 30. Limiting structure; 31. Limiting ball; 40. First reduction structure; 41. Spring 42. Adsorption component; 50. Anti-rotation structure; 51. Guide groove; 52. Guide rod; 60. One-way stop structure; 61. Stop plate; 62. Second reset component; 63. Stop tooth; 70. Transmission mechanism; 71. Arc-shaped transmission rod; 72. Gear set; 721. First transmission wheel; 7211. Guide part; 722. Second transmission wheel; 723. Connecting rod; 7231. Second receiving groove; 80. One-way transmission structure; 81. Transmission plate; 82. Stop part. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0020] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0021] like Figures 1 to 5 , Figure 7 as well as Figure 8 As shown, the knee joint prosthesis of this embodiment includes: a tibial plateau prosthesis 1, a tibial pad prosthesis 2, a femoral condyle prosthesis 3, and an extension rod device. The tibial pad prosthesis 2 is disposed above the tibial plateau prosthesis 1, the femoral condyle prosthesis 3 is adjustablely disposed on the tibial pad prosthesis 2, and the extension rod device is disposed at the bottom of the tibial plateau prosthesis 1 or the top of the femoral condyle prosthesis 3. The extension rod device includes a rod sleeve 10, a rod body 20, a limiting structure 30, and a first repositioning structure 40. The rod body 20 is nested with the rod sleeve 10 and is movably disposed on the rod sleeve 10 along the axial direction of the rod sleeve 10. The rod body 20 is provided with multiple limiting grooves 21. A limiting structure 30 is movably disposed on the sleeve 10 along its circumferential direction. The limiting structure 30 is configured to have a limiting position and a disengaged position under the control of an external tool. When the limiting structure 30 is in the limiting position, it is located within one of the limiting grooves 21 and engages with that groove to keep the sleeve 10 and the rod 20 relatively stationary. When the limiting structure 30 is in the disengaged position, it separates from the limiting groove 21, allowing the rod 20 to move relative to the sleeve 10. A first reset structure 40 applies a reset force to the limiting structure 30 to maintain it in the limiting position.

[0022] Using the technical solution of this embodiment, the knee joint prosthesis includes a tibial plateau prosthesis 1, a tibial pad prosthesis 2, a femoral condyle prosthesis 3, and an extension rod device. The extension rod device includes a rod sleeve 10, a rod body 20, a limiting structure 30, and a first reduction structure 40. The tibial plateau prosthesis 1 can support the tibial pad prosthesis 2, and the tibial pad prosthesis 2 can support the femoral condyle prosthesis 3. The rod body 20 can move along the axial direction of the rod sleeve 10, thereby adjusting the relative position between the rod body 20 and the rod sleeve 10, and thus adjusting the length of the extension rod device. An external tool can control the limiting structure 30 to move along the circumferential direction of the rod sleeve 10, thereby allowing the limiting structure 30 to switch between a limiting position and a separation position. When the limiting structure 30 is in the limiting position, it is located within one of the multiple limiting grooves 21. The limiting structure 30 can engage with the rod 20, thus maintaining the relative position between the rod 20 and the sleeve 10, thereby improving the stability of the extension rod device. When the limiting structure 30 is in the disengaged position, it separates from the limiting groove 21, meaning it avoids the rod 20, allowing the rod 20 to move relative to the sleeve 10. The first reset structure 40 can apply a reset force to the limiting structure 30, keeping it in the limiting position. The tibial plateau prosthesis 1 or the femoral condyle prosthesis 3 can be connected to the bone structure via the extension rod device. Therefore, the technical solution of this embodiment effectively solves the problem of unstable length after length adjustment of the extension rod device in related technologies.

[0023] It should be noted that the rod body 20 includes a rod body 23 and a plate 24 disposed on the outer wall of the rod body 23. The limiting groove 21 is disposed on the plate 24. The rod sleeve 10 is provided with a first installation space 14 and a second installation space 15 communicating with the first installation space 14. The second installation space 15 is connected to the first arc-shaped sliding groove 11. The first end of the rod body 20 passes through the first installation space 14, and the plate 24 is disposed in the second installation space 15.

[0024] The external tool is a magnet.

[0025] The limiting structure 30 includes multiple limiting structures 30, which are spaced apart along the axial direction of the sleeve 10.

[0026] The limiting groove 21 includes multiple grooves, which are spaced apart along the axial direction of the rod body 20.

[0027] Specifically, one of the sleeve 10 and the rod body 20 is connected to the femoral condyle prosthesis 3, and the other of the sleeve 10 and the rod body 20 is connected to the bone structure; or, one of the sleeve 10 and the rod body 20 is connected to the bone structure, and the other of the sleeve 10 and the rod body 20 is connected to the femoral condyle prosthesis 3. Figure 1 As shown, the sleeve 10 is connected to the femoral condyle prosthesis 3, and the rod body 20 is connected to the bone structure. Figure 2 As shown, the sleeve 10 is connected to the tibial plateau prosthesis 1, and the rod body 20 is connected to the bone structure.

[0028] like Figure 4 As shown, in this embodiment, the limiting structure 30 includes a limiting ball 31. A first arc-shaped groove 11 extending along the circumferential direction of the sleeve 10 is provided on the inner wall of the sleeve 10. The limiting ball 31 is slidably disposed within the first arc-shaped groove 11. The limiting ball 31 can slide within the first arc-shaped groove 11, facilitating the switching of the limiting structure 30 between a limiting position and a separating position. When the limiting ball 31 is located within the limiting groove 21, the limiting structure 30 is in the limiting position; when the limiting ball 31 is located outside the limiting groove 21, the limiting structure 30 is in the separating position.

[0029] It should be noted that the first arc-shaped slide groove 11 is connected to the second installation space 15, so that one of the multiple limiting grooves 21 can be aligned with the first arc-shaped slide groove 11.

[0030] The limiting ball 31 is made of metal and can be attracted by a magnet.

[0031] like Figure 7 As shown, in this embodiment, the first reset structure 40 includes an elastic element 41 and an adsorption element 42. The elastic element 41 is disposed within the first arc-shaped groove 11 and located between the sleeve 10 and the limiting ball 31. The adsorption element 42 is disposed on the inner wall of the sleeve 10. The elastic element 41 can apply an elastic force to the limiting ball 31, thereby causing the limiting ball 31 to move towards the limiting groove 21 and remain within the limiting groove 21. The adsorption element 42 can apply an adsorption force to the limiting ball 31, causing the limiting ball 31 to move towards the limiting groove 21 and remain within the limiting groove 21.

[0032] It should be noted that the adsorption element 42 is a magnet. The elastic element 41 is a first spring.

[0033] The sleeve 10 has a first receiving groove 16, which is connected to the first arc-shaped sliding groove 11. The adsorption member 42 is disposed in the first receiving groove 16. The elastic member 41 and the adsorption member 42 are located on both sides of the limiting ball 31.

[0034] The first reset structure 40 includes multiple first reset structures 40, and each of the multiple first reset structures 40 is arranged in a one-to-one correspondence with a multiple limiting structure 30. The first receiving groove 16 includes multiple first receiving grooves 16, and each of the multiple first receiving grooves 16 is arranged in a one-to-one correspondence with a multiple adsorption member 42.

[0035] like Figure 10 and Figure 11As shown, in this embodiment, the extension rod device further includes an anti-rotation structure 50 extending along the axial direction of the rod sleeve 10. The anti-rotation structure 50 includes a guide groove 51 and a guide rod 52. The guide groove 51 and the guide rod 52 are guided and engaged. The guide groove 51 is disposed on the inner wall of the rod sleeve 10, and the guide rod 52 is disposed on the outer wall of the rod body 20. Through the guiding engagement of the guide rod 52 and the guide groove 51, the movement of the rod body 20 relative to the rod sleeve 10 is smoother, and relative rotation between the rod body 20 and the rod sleeve 10 does not occur in the circumferential direction of the rod sleeve 10.

[0036] It should be noted that the guide groove 51 is connected to the first installation space 14.

[0037] The anti-rotation structure 50 includes multiple structures spaced apart. The multiple anti-rotation structures 50 are spaced apart along the circumferential direction of the sleeve 10.

[0038] In other embodiments, the guide rod 52 is on the inner wall of the sleeve 10, and the guide groove 51 is provided on the outer wall of the rod body 20.

[0039] like Figures 4 to 6 As shown, in this embodiment, the first end of the rod 20 passes through the rod sleeve 10, and the second end of the rod 20 is located outside the rod 20. The extension rod device also includes a one-way stop structure 60, which is disposed between the rod sleeve 10 and the rod 20 to restrict the movement of the rod 20 along the direction from the second end to the first end. By providing the one-way stop structure 60, the movement of the rod 20 along the direction from the second end to the first end is avoided after the length of the extendable rod device is adjusted, making the relative position between the rod 20 and the rod sleeve 10 more stable after the length of the extendable rod device is adjusted.

[0040] like Figures 4 to 6 As shown, in this embodiment, the one-way stop structure 60 includes a stop plate 61, a second reset member 62, and multiple stop teeth 63. The stop plate 61 is swayably disposed and engages with one of the stop teeth 63. The stop teeth 63 are disposed on the outer wall of the rod body 20, the stop plate 61 is disposed on the inner wall of the rod sleeve 10, and the second reset member 62 is disposed between the stop plate 61 and the rod sleeve 10. Through the engagement of the stop plate 61 and the stop teeth 63, movement of the rod body 20 along the direction from the second end to the first end of the rod body 20 can be prevented. The stop plate 61 can move between the multiple stop teeth 63, and the provision of the second reset member 62 allows the stop plate 61 to move out of one stop tooth 63 and then move into another stop tooth 63 adjacent to that stop tooth 63, maintaining it in a position abutting against the stop tooth 63, thus achieving the function of one-way stop.

[0041] One-way stop means to prevent the rod 20 from moving in the direction from the second end of the rod 20 to the first end of the rod 20.

[0042] It should be noted that the second reset element 62 is the second spring. The swing axis of the stop plate 61 is perpendicular to the axial direction of the rod 20. When the limiting ball 31 is located in the limiting groove 21, if there is a gap between the center of the limiting ball 31 and the plane of symmetry in the thickness direction of the convex plate 22, under the pressure of the rod 20, the limiting ball 31 is subjected to a component force perpendicular to the vertical plane, which may cause the limiting ball 31 to move outside the limiting groove 21, resulting in relative movement between the rod 20 and the sleeve 10 when the length of the extension rod device does not need to be adjusted.

[0043] In other embodiments, a stop plate 61 is disposed on the outer wall of the rod body 20, and a stop tooth 63 is disposed on the inner wall of the rod sleeve 10.

[0044] In other embodiments, the second reset member 62 is disposed between the stop plate 61 and the rod 20.

[0045] like Figure 10 and Figure 11 As shown, in this embodiment, the extension rod device further includes a transmission mechanism 70. The first end of the transmission mechanism 70 engages with the limiting ball 31, and the second end of the transmission mechanism 70 engages with the rod body 20 to enable the rod body 20 to move. When the limiting ball 31 moves, it can drive the rod body 20 to move along the axial direction of the rod sleeve 10 through the transmission mechanism 70.

[0046] It should be noted that the magnet can be an electromagnet, so as to adjust the magnetic force to ensure that when the limit ball 31 moves, it can drive the rod 20 to move through the transmission mechanism 70.

[0047] like Figure 4 , Figure 5 , Figure 7 , Figure 9 , Figure 11 as well as Figure 12 As shown, in this embodiment, the sleeve 10 is provided with an arc-shaped guide hole 12 and a radial mounting hole 13 communicating with the arc-shaped guide hole 12. The transmission mechanism 70 includes an arc-shaped transmission rod 71 and a gear set 72. The arc-shaped transmission rod 71 is movably disposed in the arc-shaped guide hole 12, and the gear set 72 is disposed in the radial mounting hole 13. The first end of the arc-shaped transmission rod 71 is connected to the limiting ball 31, and the second end of the arc-shaped transmission rod 71 is in transmission engagement with the gear set 72. The gear set 72 is in driving engagement with the rod body 20 so that the rod body 20 can move. When the limiting ball 31 moves, it can drive the arc-shaped transmission rod 71 to move within the arc-shaped guide hole 12, thereby driving the gear set 72 to move, so that the gear set 72 can drive the rod body 20 to move along the axial direction of the sleeve 10.

[0048] It should be noted that the arc-shaped guide hole 12 is connected to the radial mounting hole 13. The arc-shaped guide hole 12 extends along the circumferential direction of the sleeve.

[0049] like Figures 7 to 9 as well as Figures 13 to 16 As shown, in this embodiment, the gear set 72 includes a first transmission wheel 721, a second transmission wheel 722, and a connecting rod 723. The arc-shaped transmission rod 71 is driven to engage with the first transmission wheel 721, and the second transmission wheel 722 is driven to engage with the rod body 20. The first transmission wheel 721 is rotatably mounted on the connecting rod 723, and the second transmission wheel 722 is fixedly connected to the connecting rod 723. The connecting rod 723 is rotatably mounted on the rod sleeve 10. When the first transmission wheel 721 rotates along a first preset direction, the first transmission wheel 721 can drive the connecting rod 723 to rotate. When the first transmission wheel 721 rotates along a second preset direction opposite to the first preset direction, the first transmission wheel 721 can rotate relative to the second transmission wheel 722 while the second transmission wheel 722 remains stationary. When the arc-shaped transmission rod 71 moves along the first circumferential direction, it drives the first transmission wheel 721 to rotate along the first preset direction. The first transmission wheel 721 then drives the second transmission wheel 722 to rotate via the connecting rod 723, which in turn drives the rod body 20 to move. When the arc-shaped transmission rod 71 moves along the second circumferential direction, it drives the first transmission wheel 721 to rotate along the second preset direction. The first transmission wheel 721 rotates relative to the second transmission wheel 722 while the second transmission wheel 722 remains stationary. This allows the rod body 20 to remain stationary, facilitating the movement of the limiting ball 31 towards the direction closer to the limiting groove 21. The limiting ball 31 can then move into the limiting groove 21, or it can move to a position close to the limiting groove 21 and then move again along the first circumferential direction.

[0050] Both the first and second circumferential directions are parallel to the circumferential direction of the sleeve 10. The second transmission wheel 722 is fixedly connected to the connecting rod 723. The fixed connection means that when the extension rod device is in use, there will be no relative movement between the second transmission wheel 722 and the connecting rod 723, and the two remain relatively stationary.

[0051] The extension rod device also includes a bearing, which is fixedly mounted on the sleeve, and the connecting rod passes through the bearing so that the connecting rod 723 can rotate relative to the sleeve 10.

[0052] Specifically, when the limiting ball 31 moves to the end of the first arc-shaped slide groove 11, if the limiting groove 21 is not aligned with the first arc-shaped slide groove 11, the external tool can be removed so that the limiting ball 31 can move toward the direction closer to the limiting groove 21. The external tool can then be moved again to the direction closer to the extension rod device so that the limiting ball 31 moves away from the limiting groove 21 again. The rod body 20 is moved by the arc-shaped transmission rod 71 so that the limiting groove 21 can be aligned with the first arc-shaped slide groove 11.

[0053] It should be noted that, as Figure 15 and Figure 16 As shown, the extension rod device also includes a one-way transmission structure 80, which is disposed between the connecting rod 723 and the first transmission wheel 721. The one-way transmission structure 80 has a transmission state and a avoidance state. When the first transmission wheel 721 rotates in a first preset direction, the one-way transmission structure 80 is in the transmission state, and the first transmission wheel 721 can drive the connecting rod 723 to rotate. When the first transmission wheel 721 rotates in a second preset direction, the one-way transmission structure 80 is in the avoidance state, and the first transmission wheel 721 can rotate relative to the second transmission wheel 722 while the second transmission wheel 722 remains stationary.

[0054] The one-way transmission structure 80 includes a transmission plate 81, a stop portion 82, and a third reset member. The transmission plate 81 is rotatably disposed. One of the transmission plate 81 and the stop portion 82 is disposed on the connecting rod 723, and the other of the transmission plate 81 and the stop portion 82 is disposed on the inner wall of the first transmission wheel 721. When the one-way transmission structure 80 is in the transmission state, the transmission plate 81 protrudes from the inner wall of the first transmission wheel 721 or the connecting rod 723. When the one-way transmission structure 80 is in the avoidance state, the transmission plate 81 is located inside the connecting rod 723 or inside the first transmission wheel 721. The third reset member is disposed between the transmission plate 81 and the connecting rod 723 or between the transmission plate 81 and the first transmission wheel 721, so that the one-way transmission structure 80 is kept in the transmission state.

[0055] In this embodiment, the transmission plate 81 is disposed on the connecting rod 723, the stop part 82 is disposed on the inner wall of the first transmission wheel 721, and the third reset member is disposed between the transmission plate 81 and the connecting rod 723, as shown below. Figure 16 As shown, when the one-way transmission structure 80 is in the transmission state, the transmission plate 81 protrudes from the connecting rod 723, as... Figure 15 As shown, when the one-way transmission structure 80 is in the avoidance state, the transmission plate 81 is located inside the connecting rod 723.

[0056] The stop section is a stop groove. The transmission plate 81 is rotatably mounted on the connecting rod 723 via a rotating shaft.

[0057] It should be noted that a second receiving groove 7231 is provided on the outer surface of the connecting rod 723. When the one-way transmission structure 80 is in the avoidance state, the transmission plate 81 is located in the second receiving groove 7231.

[0058] The inner wall of the first transmission wheel 721 is also provided with a guide portion 7211, which is connected to the stop portion 82. When the first transmission wheel 721 rotates in the second preset direction, the transmission plate 81 abuts against the surface of the guide portion 7211, and the transmission plate 81 rotates into the second receiving groove 7231 under the action of the guide portion 7211.

[0059] The guide section 7211 is a guide groove.

[0060] In other embodiments, the stop portion 82 is disposed on the connecting rod 723, the transmission plate 81 is disposed on the inner wall of the first transmission wheel 721, and the third reset member is disposed between the transmission plate 81 and the first transmission wheel 721. When the one-way transmission structure 80 is in the transmission state, the transmission plate 81 protrudes from the inner wall of the first transmission wheel 721. When the one-way transmission structure 80 is in the avoidance state, the transmission plate 81 is located inside the first transmission wheel 721.

[0061] It should be noted that in other embodiments, the transmission mechanism 70 and the one-way transmission structure 80 may not be provided. The length of the extension rod device can be adjusted simply by moving the limiting structure 30 to the separation position and applying external force to the sleeve 10 and the rod body 20 respectively.

[0062] like Figure 4 , Figure 5 as well as Figure 10 As shown, in this embodiment, the arc-shaped transmission rod 71 has a first transmission tooth portion that meshes with the first transmission wheel 721. A protruding plate 22 is provided on the outer wall of the rod body 20, and a second transmission tooth portion is provided on the protruding plate 22. The second transmission wheel 722 meshes with the second transmission tooth portion. Through the meshing of the first transmission tooth portion and the first transmission wheel 721, the arc-shaped transmission rod 71 can drive the first transmission wheel 721 to rotate. Through the meshing of the second transmission wheel 722 with the second transmission tooth portion, the second transmission wheel 722 can drive the protruding plate 22 to move.

[0063] It should be noted that the protruding plate 22 is set on the rod body 23, and the rod sleeve 10 is also provided with a third mounting space 17. The protruding plate 22 is set in the third mounting space 17, and the third mounting space 17 is connected to the radial mounting hole 13.

[0064] When adjusting the length of the extension rod device, a magnet is used to attract the limiting ball 31. The limiting ball 31 can move along the circumferential direction of the sleeve 10. The limiting ball 31 can then drive the connecting rod 723 to rotate through the first transmission wheel 721. The connecting rod 723 then drives the second transmission wheel 722 to rotate. The second transmission wheel 722 can then drive the protruding plate 22 to move, and the rod body 20 can move relative to the sleeve 10, thereby realizing the length adjustment of the extension rod device.

[0065] After the length of the extension rod device is adjusted, the magnet is removed. Then, under the action of the elastic element 41 and the adsorption element 42, the limiting ball 31 can move along the circumferential direction of the rod sleeve 10 towards the adsorption element 42, and finally move into the limiting groove 21. When the limiting ball 31 moves along the circumferential direction of the rod sleeve 10 towards the adsorption element 42, the first transmission wheel 721 can rotate relative to the connecting rod 723, while the connecting rod 723 remains stationary. Therefore, the connecting rod 723 will not drive the second transmission wheel 722 to rotate, thus preventing the second transmission wheel 722 from driving the rod body 20 to move.

[0066] After implantation, the length of the extension rod can be adjusted using external tools, thus avoiding the need for a second surgery to increase its length and preventing problems such as infection.

[0067] It should be noted that the extension rod device also includes an end cap, which is located at one end of the rod sleeve 10, and the rod body 20 extends out from the other end of the rod sleeve 10. When installing the rod sleeve 10 and the rod body 20, the rod body 20 is inserted into the rod sleeve 10 from the end connected to the end cap, and then pushed out from the other end of the rod sleeve 10. By reasonably setting the structure of the rod sleeve, the limiting structure 30, the first reset structure 40, and the transmission mechanism 70 can be installed onto the rod sleeve respectively.

[0068] In the description of this invention, it should be understood that "a plurality of" means two or more. Directional terms such as "front, back, up, down, left, right," "horizontal, vertical, perpendicular, horizontal," and "top, bottom" indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. These terms are used solely for the convenience of describing the invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner or outer contours relative to the outline of each component itself.

[0069] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0070] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0071] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A knee prosthesis, characterized in that The application relates to a tibial platform prosthesis (1), a tibial spacer prosthesis (2), a femoral condyle prosthesis (3) and an extension rod device, the tibial spacer prosthesis (2) being arranged above the tibial platform prosthesis (1), the femoral condyle prosthesis (3) being adjustably arranged on the tibial spacer prosthesis (2), and the extension rod device being arranged at the bottom of the tibial platform prosthesis (1) or at the top of the femoral condyle prosthesis (3), the extension rod device comprising: a rod sleeve (10); a rod body (20) which is nested with the rod sleeve (10) and movably arranged on the rod sleeve (10) along the axial direction of the rod sleeve (10), the rod body (20) being provided with a plurality of limiting grooves (21); a limiting structure (30) which is movably arranged on the rod sleeve (10) along the circumferential direction of the rod sleeve (10), the limiting structure (30) being configured to have a limiting position and a separation position under the control of an external tool, when the limiting structure (30) is in the limiting position, the limiting structure (30) is located in one of the limiting grooves (21) and is limitedly matched with the limiting groove (21) to keep the rod sleeve (10) and the rod body (20) relatively static, when the limiting structure (30) is in the separation position, the limiting structure (30) is separated from the limiting groove (21) to enable the rod body (20) to move relative to the rod sleeve (10); and a first reset structure (40) which applies a reset force to the limiting structure (30) to keep the limiting structure (30) in the limiting position. The limiting structure (30) comprises a limiting ball (31), and an inner wall of the rod sleeve (10) is provided with a first arc-shaped sliding groove (11) extending along the circumferential direction of the rod sleeve (10), and the limiting ball (31) is slidably arranged in the first arc-shaped sliding groove (11). The first reset structure (40) comprises an elastic member (41) and / or a suction accessory (42), wherein the elastic member (41) is arranged in the first arc-shaped sliding groove (11) and located between the rod sleeve (10) and the limiting ball (31), and the suction accessory (42) is arranged on the inner wall of the rod sleeve (10). The extension rod device further comprises a rotation-stopping structure (50) extending along the axial direction of the rod sleeve (10), the rotation-stopping structure (50) comprising a guide groove (51) and a guide rod (52), the guide groove (51) and the guide rod (52) being in guiding cooperation, one of the guide groove (51) and the guide rod (52) being arranged on the inner wall of the rod sleeve (10), and the other of the guide groove (51) and the guide rod (52) being arranged on the outer wall of the rod body (20). ​ ​ 2. The knee prosthesis of claim 1, wherein, ​ 3. The knee prosthesis of claim 2, wherein, ​ 4. The knee prosthesis of any of claims 1 to 3, wherein, ​ 5. The knee prosthesis of any of claims 1 to 3, wherein, The first end of the rod body (20) is arranged in the rod sleeve (10), and the second end of the rod body (20) is located outside the rod body (20), the lengthening rod device further comprises a one-way stop structure (60), the one-way stop structure (60) is arranged between the rod sleeve (10) and the rod body (20) to limit the movement of the rod body (20) in the direction from the second end of the rod body (20) to the first end of the rod body (20).

6. The knee prosthesis of claim 5, wherein, The one-way stop structure (60) comprises a stop plate (61), a second reset member (62) and a plurality of stop teeth (63), the stop plate (61) is arranged in an oscillating manner and is limited in position with one of the stop teeth (63), one of the stop plate (61) and the stop teeth (63) is arranged on the outer wall of the rod body (20), the other of the stop plate (61) and the stop teeth (63) is arranged on the inner wall of the rod sleeve (10), and the second reset member (62) is arranged between the stop plate (61) and the rod sleeve (10) or the rod body (20).

7. The knee prosthesis of claim 2 or 3, wherein, The lengthening rod device further comprises a transmission mechanism (70), the first end of the transmission mechanism (70) is matched with the limiting ball (31), and the second end of the transmission mechanism (70) is drivingly matched with the rod body (20) to enable the movement of the rod body (20).

8. The knee prosthesis of claim 7, wherein, The rod sleeve (10) is provided with an arc-shaped guide hole (12) and a radial mounting hole (13) in communication with the arc-shaped guide hole (12), the transmission mechanism (70) comprises an arc-shaped transmission rod (71) and a gear set (72), the arc-shaped transmission rod (71) is movably arranged in the arc-shaped guide hole (12), the gear set (72) is arranged in the radial mounting hole (13), the first end of the arc-shaped transmission rod (71) is connected with the limiting ball (31), the second end of the arc-shaped transmission rod (71) is drivingly matched with the gear set (72), and the gear set (72) is drivingly matched with the rod body (20) to enable the movement of the rod body (20).

9. The knee prosthesis of claim 8, wherein, The gear set (72) comprises a first transmission wheel (721), a second transmission wheel (722) and a connecting rod (723), the arc-shaped transmission rod (71) is drivingly matched with the first transmission wheel (721), the second transmission wheel (722) is drivingly matched with the rod body (20), the first transmission wheel (721) is rotatably arranged on the connecting rod (723), the second transmission wheel (722) is fixedly connected with the connecting rod (723), and the connecting rod (723) is rotatably arranged on the rod sleeve (10), when the first transmission wheel (721) rotates in a first preset direction, the first transmission wheel (721) can drive the connecting rod (723) to rotate, and when the first transmission wheel (721) rotates in a second preset direction opposite to the first preset direction, the first transmission wheel (721) can rotate relative to the second transmission wheel (722) and the second transmission wheel (722) remains stationary.

10. The knee prosthesis of claim 9, wherein, The arc-shaped transmission rod (71) has a first transmission gear part which is engaged with the first transmission wheel (721), and / or a convex plate (22) is arranged on the outer wall of the rod body (20), the convex plate (22) is provided with a second transmission gear part, and the second transmission wheel (722) is engaged with the second transmission gear part.

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