CN113397768A

CN113397768A - Rotary platform knee joint prosthesis

Info

Publication number: CN113397768A
Application number: CN202110806318.9A
Authority: CN
Inventors: 赵梦宇
Original assignee: Beijing Lidakang Technology Co Ltd
Current assignee: Beijing Lidakang Technology Co Ltd
Priority date: 2021-07-16
Filing date: 2021-07-16
Publication date: 2021-09-17

Abstract

The application relates to a knee joint prosthesis, especially relates to a rotary platform knee joint prosthesis, and its technical scheme main points are: a rotary platform knee joint prosthesis includes a tibial pad and a tibial tray; the surface of the tibia pad close to the tibia support is formed with a rotary convex piece, and the tibia support is provided with a rotary groove for the rotary convex piece to insert and rotate; the rotating convex part is provided with an anti-falling part, and the distance from the position of the anti-falling part farthest from the axis of the rotating convex part to the axis of the rotating convex part is greater than the radius of the rotating groove; the purpose of reducing the possibility of knee joint falling caused by the mutual separation between the tibial pad and the tibial tray is achieved.

Description

Rotary platform knee joint prosthesis

Technical Field

The present application relates to a knee joint prosthesis, and more particularly, to a rotary platform knee joint prosthesis.

Background

With the improvement of the operation technology and the improvement of the knee joint prosthesis, the total knee joint replacement operation is mature day by day, and various knee joint products are more and more on the market.

The fixed platform knee joint prosthesis recorded in the related technology can not meet the requirements of the human knee joint on the rotary motion except for the flexion and extension motion in the motion process; therefore, the rotary platform knee joint prosthesis has become popular in the market, and the rotary platform knee joint prosthesis described in the related art includes a tibial pad and a tibial tray which can rotate with each other, and although the requirement of the rotary motion at the knee joint is satisfied, the separation between the tibial pad and the tibial tray cannot be effectively limited, and the tibial pad and the tibial tray are attached to each other only by the pressure provided by the human body bones and tissues, so that the tibial pad and the tibial tray are still easily separated from each other, and the knee joint is easily detached.

Disclosure of Invention

In order to reduce the possibility of knee joint loss caused by the separation between the tibial pad and the tibial tray, the application provides a rotary platform knee joint prosthesis.

The application provides a rotary platform knee joint prosthesis adopts following technical scheme:

a rotary platform knee joint prosthesis comprising a tibial pad and a tibial tray; the surface of the tibia pad close to the tibia support is formed with a rotary convex piece, and the tibia support is provided with a rotary groove for the rotary convex piece to insert and rotate; the rotating convex part is provided with an anti-falling part, and the distance from the position of the anti-falling part farthest from the axis of the rotating convex part to the axis of the rotating convex part is greater than the radius of the rotating groove.

By adopting the technical scheme, the rotary convex piece is inserted into the rotary groove and rotates in the tibial tray, so that the tibial tray and the tibial pad rotate around the axis of the rotary convex piece; in the process, the anti-falling part is embedded into the rotating groove, and the distance from the position, farthest away from the axis of the rotating convex part, of the anti-falling part to the axis of the rotating convex part is larger than the radius of the rotating groove, so that the anti-falling part is difficult to pull out from the rotating groove along the axial direction of the rotating groove, the axial limiting effect of the rotating convex part in the rotating groove is achieved, and the possibility that the knee joint falls off due to the fact that the shin pad and the shin tray are separated from each other is reduced.

Optionally, the rotating convex part comprises a plurality of rotating convex blocks, the plurality of rotating convex blocks are distributed along the circumferential direction of the rotating groove and jointly form a cylindrical rotating convex part, and a gap exists between adjacent rotating convex blocks along the circumferential direction; the anti-falling part comprises a plurality of anti-falling plates which correspond to the rotating convex blocks one by one, the anti-falling plates jointly form a circular plate-shaped anti-falling part coaxial with the rotating convex part, a gap exists between every two adjacent anti-falling plates along the circumferential direction, and the diameter of the anti-falling part is larger than that of the rotating convex part and that of the rotating groove; the shin support is provided with an anti-falling groove for the anti-falling piece to be placed in, and the anti-falling groove is arranged on one side of the rotating groove far away from the shin pad.

By adopting the technical scheme, the rotating lugs are inserted into the rotating grooves and can rotate in the rotating grooves around the axes of the rotating lugs, and in the process, the anti-falling plates and the rotating lugs incline in the direction of approaching each other so that the anti-falling plates can enter the anti-falling grooves through the rotating grooves; and the anticreep board can't be backward through rotatory recess, also can't be to the mutual direction alternate segregation of keeping away from between tibial pad and the shin bone support, has realized dragging between the axial spacing to tibial pad and shin bone.

Optionally, a chamfer or a fillet is processed on the edge of one end of the anti-falling plate away from the tibia pad; the edge of the rotary groove which is flush with the surface of the tibial tray is provided with a chamfer or a fillet.

Through adopting above-mentioned technical scheme, at the in-process through rotatory recess, the edge of anticreep board receives the radial pressure of rotatory recess cell wall to its effect, and the anticreep board can take place deformation voluntarily and can make things convenient for inserting of anticreep board through rotatory recess in order to supply self.

Optionally, the tibia support is provided with a circular arc-shaped limiting block, and the limiting block extends along the circumferential direction of the rotating groove; the tibia pad is provided with a circular arc-shaped limiting groove for the limiting block to be placed in, and the limiting groove extends along the circumferential direction of the rotating convex piece; the width of the limiting groove is equal to that of the limiting block, and the circumferential angle of the limiting groove is larger than that of the limiting block.

Through adopting above-mentioned technical scheme, the stopper can be at the inside rotation of a rotation angle within range of spacing inslot, and then realizes the restriction to the mutual rotation angle scope between shin bone pad and the shin bone pad, has prevented to take place excessive pivoted condition between shin bone pad and the shin bone pad.

Optionally, a circular arc-shaped limiting block is formed on the groove wall of the anti-falling groove along the circumferential direction, a circular arc-shaped limiting groove for the limiting block to be placed in is formed on the circumferential surface of the rotating convex piece, and the limiting groove extends along the circumferential direction of the rotating convex piece; the width of the limiting groove is equal to that of the limiting block, the circumferential angle of the limiting groove is larger than that of the limiting block, and the circumferential angle of the limiting block is larger than that corresponding to a gap between adjacent rotating lugs.

By adopting the technical scheme, in the process that the rotary convex piece is inserted into the rotary groove, the limiting block extrudes the rotary convex piece and deforms the rotary convex piece until the limiting block is embedded into the limiting groove; the stopper can be at the inside rotation of a rotation angle within range of spacing inslot, and then realizes the restriction to the mutual rotation angle scope between shin bone pad and the shin bone pad, has prevented to take place the excessive pivoted condition between shin bone pad and the shin bone pad.

Optionally, the difference between the circumferential angle of the limiting groove and the circumferential angle of the limiting block is 20-40 °.

By adopting the technical scheme, the rotation angle range of the limiting block in the limiting groove is limited to 20-40 degrees, so that the rotation angle range between the tibial pad and the tibial tray is limited to 20-40 degrees, namely the tibial pad and the tibial tray can respectively rotate 10-20 degrees in two directions, the rotation of the knee joint in a required angle range is met, and meanwhile, the excessive rotation between the tibial pad and the tibial tray is prevented.

Optionally, the rotary convex part is a rotary convex column with an axis vertical to the surface of the tibial pad, a tibial intramedullary pin is formed on one side of the tibial tray away from the tibial pad, and the rotary groove extends towards the interior of the tibial intramedullary pin and is matched with the rotary convex column; the anti-drop piece is an anti-drop screw which is abutted against the peripheral surface of the rotary convex column, and the anti-drop screw is spirally arranged on the tibia intramedullary needle and extends towards the inside of the rotary groove; the rotating convex column is provided with a limiting groove along the circumferential direction, the width of the limiting groove is equal to the major diameter of the anti-disengaging screw, and the end of the anti-disengaging screw is embedded into the limiting groove and is in sliding connection with the groove wall of the limiting groove.

Through adopting above-mentioned technical scheme, the anticreep screw can rotate at the spacing inslot portion, can bear the axial force along rotatory projection direction simultaneously, can hinder rotatory projection promptly and deviate from the shin bone intramedullary nail is inside, has realized holding in the palm axial positioning between to shin bone pad and shin bone.

Optionally, the limiting groove is an arc-shaped limiting groove, and the circumferential angle of the limiting groove is 20-40 °.

Through adopting above-mentioned technical scheme, the condition of taking place excessive rotation between tibial pad and the shin bone support has been prevented when satisfying knee joint rotation at required angle within range.

Optionally, the diameter of the rotating post decreases gradually in a direction from proximal to distal to the tibial pad; the rotary convex column is connected with the groove wall of the rotary groove in a Morse taper manner.

Through adopting above-mentioned technical scheme, can make and bear certain axial force between rotatory projection and the rotatory recess, make the cooperation of the two more reliable.

Optionally, the tibial tray is made of cobalt-chromium-molybdenum alloy or titanium alloy; the tibia pad is made of high cross-linked ultra-high molecular weight polyethylene mixed with vitamin E.

In summary, the present application has the following technical effects:

1. the rotary convex part and the anti-falling part are arranged, and the corresponding rotary groove and the anti-falling groove are formed, so that the possibility of knee joint falling caused by the mutual separation between the tibia pad and the tibia tray is reduced;

2. the limiting block is arranged and the limiting groove is formed, so that the mutual rotation angle range between the tibial tray and the tibial pad is limited, and the situation of excessive rotation between the tibial pad and the tibial tray is prevented;

3. through having set up the anticreep bolt and having seted up the spacing groove, and then realize the restriction to the mutual turned angle scope between shin bone support and the shin bone pad, prevented to take place excessively pivoted condition between shin bone pad and the shin bone support.

Drawings

FIG. 1 is a schematic view of an exploded assembly of a rotary platform knee prosthesis according to a first embodiment;

FIG. 2 is a schematic view of a tibial insert according to a first embodiment;

fig. 3 is an exploded view of the tibial tray of the first embodiment;

FIG. 4 is a schematic view of the tibial pad of the second embodiment;

fig. 5 is a schematic structural view of a tibial tray in the second embodiment;

fig. 6 is a schematic view of the exploded structure of the rotary platform knee joint prosthesis according to the third embodiment.

In the drawings, 1, a tibial pad; 2. a tibial tray; 3. rotating the male member; 31. rotating the projection; 32. rotating the convex column; 4. rotating the groove; 5. a drop-off prevention member; 51. an anti-drop plate; 52. an anti-drop screw; 6. a drop-proof groove; 7. a limiting block; 8. a limiting groove; 9. a tibial intramedullary pin; 10. and (7) an anti-drop cover.

Detailed Description

The present application is described in further detail below with reference to the attached drawings.

Referring to fig. 1, the present application provides a rotary platform knee joint prosthesis, which comprises a tibial pad 1 made of a high cross-linked ultra-high molecular weight polyethylene material mixed with vitamin E, and a tibial tray 2 made of a cobalt-chromium-molybdenum alloy or titanium alloy material, wherein a tibial intramedullary pin 9 for inserting into a tibial medullary cavity is formed on one side of the tibial tray 2 away from the tibial pad 1; in order to realize the mutual rotation between the tibial tray 2 and the tibial pad 1, a rotary convex part 3 is integrally formed on the surface of the tibial pad 1 close to the tibial tray 2, a rotary groove 4 for placing the rotary convex part 3 is formed on the surface of the tibial tray 2 close to the tibial pad 1, and the rotary convex part 3 is a rotary body and can rotate in the rotary groove 4; in order to realize the axial positioning between the tibial tray 2 and the tibial pad 1, the anti-disengaging part 5 is arranged on the rotating convex part 3, the distance from the position, farthest away from the axis of the rotating convex part 3, of the anti-disengaging part 5 to the axis of the rotating convex part 3 is greater than the radius of the rotating groove 4, the anti-disengaging part 5 is difficult to pull out from the rotating groove 4 along the axial direction of the rotating groove 4, and the possibility that the knee joint falls off due to the fact that the tibial pad 1 is separated from the tibial tray 2 is reduced.

The first embodiment is as follows:

referring to fig. 1 and 2, the rotary convex part 3 is cylindrical and is divided into a plurality of rotary convex blocks 31, in the embodiment, four rotary convex blocks 31 are provided and uniformly distributed along the circumferential direction of the rotary convex part 3, that is, the rotary convex blocks 31 are in a quarter-cylindrical structure, and a gap along the circumferential direction of the rotary convex part 3 exists between two adjacent rotary convex blocks 31; the anti-falling plate 51 is coaxially formed at one end of each rotating lug 31 far away from the tibia pad 1, the anti-falling plate 51 is of a quarter circular plate-shaped structure, a gap along the circumferential direction of the rotating convex piece 3 exists between every two adjacent anti-falling plates 51, and the four anti-falling plates 51 form the circular plate-shaped anti-falling piece 5; further, referring to fig. 3, the rotating groove 4 is adapted to the rotating protrusion 3, the diameter of the anti-slip member 5 is larger than that of the rotating protrusion 3, the diameter of the rotating groove 4 is equal to that of the rotating protrusion 3, and the height of the rotating groove 4 is equal to that of the rotating protrusion 3; the shin holds in the palm 2 and offers the anticreep groove 6 with rotatory recess 4 intercommunication in the one side that rotatory recess 4 kept away from shin pad 1, anticreep groove 6 be with the anticreep groove 6 of 5 looks adaptations of anticreep piece, and then the diameter in anticreep groove 6 is greater than the diameter of rotatory recess 4.

The surfaces of the tibia pad 1 and the tibia tray 2 which are close to each other are attached to each other, in the process, the rotating convex piece 3 is inserted into the rotating groove 4 and can rotate in the rotating groove 4 around the axis of the rotating convex piece, and the diameter of the anti-falling piece 5 is larger than that of the rotating groove 4, so that in the process that the rotating convex piece 3 is inserted into the rotating groove 4, the anti-falling plate 51 is extruded by the groove wall of the rotating groove 4 and deforms, and meanwhile, the rotating convex pieces 31 are driven to incline towards the direction close to each other, so that the anti-falling plate 51 can pass through the rotating groove 4 and enter the anti-falling groove 6; after anticreep board 51 entered into anticreep groove 6 inside, anticreep board 51 has sufficient space to kick-back, rotatory lug 31 resumes to the normality, rotatory lug 31 is located inside rotatory recess 4 and the anticreep piece is located anticreep groove 6 inside this moment, because anticreep board 51 is apart from the distance of the 3 axes of rotatory protruding piece in the position department of rotatory protruding piece 3 axes farthest distance, anticreep 5's radius promptly, be greater than the radius of rotatory recess 4, and then anticreep 5 can not be backward through rotatory recess 4, also can't be to the mutual direction alternate segregation of keeping away from between tibia pad 1 and the shin bone support 2, realized dragging between the axial spacing to shin bone pad 1 and shin bone.

Referring to fig. 2 and 3, in order to facilitate the anti-falling part 5 to pass through the rotary groove 4, a chamfer or a fillet is processed at the edge of one end of the anti-falling part 5 away from the tibial pad 1, and a chamfer or a fillet is processed at the edge of the groove end of the rotary groove 4 flush with the surface of the tibial tray 2; in the process of impressing rotatory protruding piece 3 to rotatory recess 4 inside, anticreep piece 5 also inserts to rotatory recess 4 inside thereupon, at this in-process, the chamfer face of anticreep board 51 and the cell wall fillet face of rotatory recess 4 extrude each other, the edge of anticreep board 51 and then receive the radial pressure of rotatory recess 4 cell wall to its effect, anticreep board 51 can take place spontaneously and deform in order to supply self to pass through rotatory recess 4, and then made things convenient for the insertion of anticreep board 51.

Referring to fig. 1, although the above-mentioned solution meets the requirement of mutual rotation between the tibial pad 1 and the tibial tray 2, the situation of excessive rotation between the tibial pad 1 and the tibial tray 2 still needs to be avoided, for this reason, a circular arc-shaped limiting block 7 is formed on the surface of the tibial tray 2 close to the tibial pad 1, and the limiting block 7 extends along the circumferential direction of the rotation groove 4; a limiting groove 8 for inserting a limiting block 7 is formed in the surface, close to the tibial tray 2, of the tibial pad 1, the limiting groove 8 is a circular arc-shaped limiting groove 8 coaxial with the rotary convex part 3, the groove width of the limiting groove 8 is equal to the width of the limiting block 7, the circumferential angle corresponding to the limiting groove 8 is larger than the circumferential angle corresponding to the limiting block 7, further, the difference between the circumferential angle of the limiting groove 8 and the circumferential angle of the limiting block 7 is 20-40 degrees, and in the embodiment, the difference between the circumferential angle of the limiting groove 8 and the circumferential angle of the limiting block 7 is 30 degrees; and then can make stopper 7 rotate in the rotation angle range of 30 in spacing groove 8, and then make between tibial pad 1 and the shin bone support 2 can only rotate maximum angle 15 respectively to two opposite directions, prevented taking place the condition of excessive rotation between tibial pad 1 and the shin bone support 2 when satisfying the knee joint and rotating in required angle range.

Example two:

referring to fig. 4 and 5, the difference between the first embodiment and the second embodiment is that the limiting groove 8 is different from the limiting block 7, in the present embodiment, the limiting groove 8 is opened on the circumferential surface of the rotating male member 3, and the limiting block 7 is molded on the circumferential surface of the rotating female groove 4.

The limiting groove 8 is a circular arc-shaped limiting groove 8 which is coaxially arranged with the rotary convex part 3, the limiting block 7 is a circular arc-shaped limiting block 7 which is coaxially arranged with the rotary groove 4, the width of the limiting block 7 is equal to the groove width of the limiting groove 8, and the limiting block 7 can be embedded into the limiting groove 8 and rotate around the axis of the rotary groove 4 in the limiting groove 8; in addition, the circumferential angle corresponding to the stopper groove 8 is larger than the circumferential angle corresponding to the stopper 7, and the circumferential angle corresponding to the stopper 7 is larger than the circumferential angle corresponding to the gap between the adjacent rotation projections 31, so that the stopper 7 is prevented from being caught in the gap between the adjacent two rotation projections 31.

In the process of inserting the rotary convex part 3 into the rotary groove 4, the limiting block 7 extrudes the rotary convex part 3 and enables the rotary convex part 3 to deform, and the limiting block 7 is embedded into the limiting groove 8; further, the difference between the circumferential angle of the limiting groove 8 and the circumferential angle of the limiting block 7 is 20-40 °, and in this embodiment, the difference between the circumferential angle of the limiting groove 8 and the circumferential angle of the limiting block 7 is 30 °; and then can make stopper 7 rotate in 30 rotation angle within range in spacing groove 8, and then make between tibial pad 1 and the shin bone support 2 can only rotate maximum angle 15 respectively to two opposite directions, prevented taking place the condition of excessive rotation between tibial pad 1 and the shin bone support 2 when satisfying the knee joint and rotating in required angle within range.

In this embodiment, two limiting blocks 7 are provided and respectively disposed at two opposite sides inside the rotating groove 4; the two limit grooves 8 are correspondingly arranged and are respectively arranged at the two sides of the rotary convex part 3.

Example three:

referring to fig. 6, the present embodiment is different from the first embodiment in the difference of the rotation protrusion 3, the rotation groove 4 and the separation preventing member 5.

In the embodiment, the rotating groove 4 is coaxially opened with the tibia intramedullary nail 9, and the rotating groove 4 penetrates through the tibia support 2 and extends towards the inside of the tibia intramedullary nail 9; the rotary convex part 3 is a rotary convex column 32 which is integrally formed on the surface of the tibial pad 1 close to the tibial tray 2, the axial direction of the rotary convex column 32 is vertical to the surface of the tibial pad 1 and is coaxially arranged with the rotary groove 4, the rotary groove 4 is matched with the rotary convex column 32 and can be used for the rotary convex column 32 to rotate in the rotary groove, and further the mutual rotation between the tibial pad 1 and the tibial tray 2 is realized; in addition, the diameter of the rotary convex column 32 is gradually reduced along the direction from the close to the far away from the tibia pad 1, and a morse taper connection is formed between the rotary convex column 32 and the groove wall of the rotary groove 4, so that a certain axial force is carried between the rotary convex column 32 and the rotary groove 4.

Furthermore, the anti-slip part 5 is an anti-slip screw 52 which is abutted with the rotary convex column 32, the anti-slip screw 52 is screwed on the tibial intramedullary nail 9 and extends towards the inside of the rotary groove 4, and the axis of the anti-slip screw 52 is coplanar and vertical to the axis of the rotary convex column 32; the circumferential surface of the rotary convex column 32 is coaxially provided with a circular arc-shaped limiting groove 8, the width of the limiting groove 8 is equal to the major diameter of the anti-falling screw 52, and the end part of the anti-falling screw 52 is embedded into the limiting groove 8 and is in sliding connection with the groove wall of the limiting groove 8; further, the limiting groove 8 is a circular arc-shaped limiting groove 8, the circumferential angle of the limiting groove 8 is 20-40 °, and in the embodiment, the circumferential angle corresponding to the limiting groove 8 is 15 °.

Screwing the anti-disengaging screw 52 to enable the end of the anti-disengaging screw 52 to move towards the direction close to the bottom of the rotating groove 4, until the screwing anti-disengaging screw 52 is inserted into the rotating groove 4, the anti-disengaging screw 52 can slide relative to the limiting groove 8 in the limiting groove 8, and can bear the axial force along the direction of the rotating convex column 32, namely, the rotating convex column 32 can be prevented from being disengaged from the inner part of the tibia intramedullary nail 9, so that the axial positioning between the tibia pad 1 and the tibia support 2 is realized.

In addition, the limitation of the radian of the limiting groove 8 can play a role in limiting the angular range for the rotation of the anti-falling screw 52 in the limiting groove 8, i.e. the angular range of the rotation of the anti-falling screw 52 in the limiting groove 8 is limited to 20 to 40 degrees, so that the angular rotation range between the tibial pad 1 and the tibial tray 2 is limited to 20 to 40 degrees, i.e. the tibial pad 1 and the tibial tray 2 can respectively rotate 10 to 20 degrees in two directions, and the excessive rotation between the tibial pad 1 and the tibial tray 2 is prevented while the rotation of the knee joint in the required angular range is met.

In the present embodiment, two retaining screws 52 are provided and are respectively provided on both sides of the tibial intramedullary nail 9; the two limit grooves 8 are correspondingly arranged and are respectively arranged at two sides of the rotary convex column 32.

In the process of mutual rotation of the tibial pad 1 and the tibial tray 2, friction exists between the anti-falling screw 52 and the groove wall of the limiting groove 8 while bearing pressure along the radial direction of the anti-falling screw, the anti-falling screw 52 further bears torque provided by the groove wall of the limiting groove 8, and the anti-falling screw 52 is easy to rotate and is separated from the tibial intramedullary pin 9.

In order to prevent this, the retaining cap 10 is screwed onto the outer wall of the tibial intramedullary nail 9, and the inner bottom of the retaining cap 10 abuts against the end face of the head of the retaining screw 52 to prevent the retaining screw 52 from moving in the radial direction of the tibial intramedullary nail 9, thereby preventing the retaining screw 52 from rotating on the tibial intramedullary nail 9.

The present embodiment is only for explaining the present application, and it is not limited to the present application, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present application.

Claims

1. A rotary platform knee joint prosthesis, comprising a tibial pad (1) and a tibial tray (2); the method is characterized in that: a rotary convex part (3) is formed on the surface of the tibia pad (1) close to the tibia support (2), and a rotary groove (4) for the rotary convex part (3) to insert and rotate is formed in the tibia support (2); the anti-dropping part (5) is arranged on the rotary convex part (3), and the distance from the position, farthest from the axis of the rotary convex part (3), of the anti-dropping part (5) to the axis of the rotary convex part (3) is larger than the radius of the rotary groove (4).

2. A rotary platform knee joint prosthesis according to claim 1, wherein: the rotary convex part (3) comprises a plurality of rotary convex blocks (31), the rotary convex blocks (31) are distributed along the circumferential direction of the rotary groove (4) and form a cylindrical rotary convex part (3) together, and gaps exist between the adjacent rotary convex blocks (31) along the circumferential direction; the anti-falling part (5) comprises a plurality of anti-falling plates (51) which correspond to the rotating convex blocks (31) one by one, the anti-falling plates (51) jointly form the anti-falling part (5) which is in a circular plate shape and coaxial with the rotating convex part (3), a gap is formed between every two adjacent anti-falling plates (51) along the circumferential direction, and the diameter of the anti-falling part (5) is larger than that of the rotating convex part (3) and that of the rotating groove (4); the shin support (2) is provided with a slip-off preventing groove (6) for placing the slip-off preventing piece (5), and the slip-off preventing groove (6) is arranged on one side of the rotating groove (4) far away from the shin pad (1).

3. A rotary platform knee joint prosthesis according to claim 2, wherein: the edge of one end of the anti-falling plate (51) far away from the tibia pad (1) is provided with a chamfer or a fillet; the edge of the rotary groove (4) which is flush with the surface of the tibia support (2) is provided with a chamfer or a fillet.

4. A rotary platform knee joint prosthesis according to claim 2, wherein: the tibia support (2) is provided with a circular arc-shaped limiting block (7), and the limiting block (7) extends along the circumferential direction of the rotating groove (4); the tibia pad (1) is provided with a circular arc-shaped limiting groove (8) for the limiting block (7) to be placed in, and the limiting groove (8) extends along the circumferential direction of the rotary convex piece (3); the width of the limiting groove (8) is equal to that of the limiting block (7), and the circumferential angle of the limiting groove (8) is larger than that of the limiting block (7).

5. A rotary platform knee joint prosthesis according to claim 2, wherein: arc-shaped limiting blocks (7) are formed on the groove walls of the anti-falling grooves (6) along the circumferential direction, arc-shaped limiting grooves (8) for the limiting blocks (7) to be placed into are formed in the circumferential surface of the rotating convex piece (3), and the limiting grooves (8) extend along the circumferential direction of the rotating convex piece (3); the width of the limiting groove (8) is equal to that of the limiting block (7), the circumferential angle of the limiting groove (8) is larger than that of the limiting block (7), and the circumferential angle of the limiting block (7) is larger than that corresponding to the gap between the adjacent rotating lugs (31).

6. A rotary platform knee joint prosthesis according to claim 4 or 5, wherein: the difference value between the circumferential angle of the limiting groove (8) and the circumferential angle of the limiting block (7) is 20-40 degrees.

7. A rotary platform knee joint prosthesis according to claim 1, wherein: the rotary convex piece (3) is a rotary convex column (32) with the axis vertical to the surface of the tibia pad (1), a tibia intramedullary pin (9) is formed on one side of the tibia support (2) far away from the tibia pad (1), and the rotary groove (4) extends towards the inside of the tibia intramedullary pin (9) and is matched with the rotary convex column (32); the anti-falling part (5) is an anti-falling screw (52) which is abutted against the peripheral surface of the rotary convex column (32), and the anti-falling screw (52) is spirally arranged on the tibial intramedullary nail (9) and extends towards the inside of the rotary groove (4); limiting grooves (8) are formed in the rotating convex columns (32) along the circumferential direction of the rotating convex columns, the width of each limiting groove (8) is equal to the large diameter of each anti-falling screw (52), and the end portions of the anti-falling screws (52) are embedded into the limiting grooves (8) and are in sliding connection with the groove walls of the limiting grooves (8).

8. The rotary platform knee prosthesis of claim 7, wherein: the limiting groove (8) is a circular arc-shaped limiting groove (8), and the circumferential angle of the limiting groove (8) is 20-40 degrees.

9. A rotary platform knee joint prosthesis according to claim 7 or 8, wherein: the diameter of the rotary convex column (32) is gradually reduced along the direction from the approach to the far away from the tibia pad (1); the rotary convex column (32) is connected with the groove wall of the rotary groove (4) in a Morse taper manner.

10. A rotary platform knee joint prosthesis according to claim 1, wherein: the tibia support (2) is a cobalt-chromium-molybdenum alloy or titanium alloy tibia support (2); the tibia pad (1) is made of high cross-linked ultra-high molecular weight polyethylene (UHMWPE) mixed with vitamin E.