Unicondylar knee prosthesis

Abstract

The application discloses a single-knee joint prosthesis, and relates to the technical field of medical devices, which comprises a tibial prosthesis and a gasket, a clamping groove is formed in the tibial prosthesis, and a first locking groove is formed in the bottom wall of the clamping groove; a first locking part is arranged at one end of the tibial prosthesis and faces the gasket, and the first locking part is used for plug-in cooperation with the first locking groove. The application has the effect of reducing the abrasion of the gasket caused by deformation and micro-motion when the femoral prosthesis rotates.

Description

Technical Field

[0001] This application relates to the technical field of medical devices, and in particular to a unicompartmental knee joint prosthesis. Background Technology

[0002] One of the treatment options for knee osteoarthritis is unicompartmental knee arthroplasty. Unicompartmental knee arthroplasty has the advantages of minimal trauma, less bleeding, and faster recovery. It provides a more minimally invasive treatment option for patients who do not need total knee replacement and are not suitable for osteotomy. Unicompartmental knee arthroplasty mainly uses a unicompartmental knee joint prosthesis to replace the surface of the knee joint.

[0003] A unicompartmental joint prosthesis includes a tibial prosthesis, a spacer, and a femoral prosthesis. The tibial prosthesis is installed on the tibial matrix, and a groove is formed at the end of the tibial prosthesis away from the tibial matrix. The spacer is engaged inside the groove. The femoral prosthesis is installed on the femoral matrix and abuts against the middle of the spacer. When the femoral matrix and tibial matrix rotate relative to each other, the femoral prosthesis abuts against the spacer and rotates relative to each other, thereby replacing the original necrotic portion of the femoral matrix and tibial matrix.

[0004] However, in related technologies, the contact point between the femoral prosthesis and the spacer is located in the middle of the spacer. When the femoral prosthesis rotates, the contact point between the spacer and the inner wall of the slot is prone to deformation and fretting, thereby accelerating the wear of the spacer and affecting the service life of the unicompartmental knee joint prosthesis. When the wear is severe, the spacer may easily disengage from the slot, causing the unicompartmental knee joint prosthesis to fail. Summary of the Invention

[0005] In order to reduce wear on the spacer due to deformation and micromovement during femoral prosthesis rotation, this application provides a unicompartmental knee joint prosthesis.

[0006] This application provides a unicompartmental knee joint prosthesis, which adopts the following technical solution: A unicompartmental knee prosthesis includes, A tibial prosthesis, wherein a slot is provided on the tibial prosthesis and a first locking groove is provided on the bottom wall of the slot; A gasket, wherein a first locking part is provided at the middle of the gasket facing the tibial prosthesis, and the first locking part is used to engage with a first locking groove.

[0007] By adopting the above technical solution, the middle part of the pad is locked to the tibial prosthesis through the insertion and engagement of the first locking part and the first locking groove. When the femoral prosthesis moves relative to the pad, the first locking part bears more force, thereby reducing the force on the edge of the pad. This makes the force on the edge and middle of the pad more uniform, thereby reducing the deformation and micro-movement of the pad, reducing the wear caused by the deformation and micro-movement of the pad, and improving the service life of the unicompartmental knee joint prosthesis.

[0008] Optionally, a plurality of second locking parts are slidably connected to the side wall of the first locking groove. The moving direction of the second locking parts is perpendicular to the length direction of the first locking groove. The second locking parts are used to move closer to the first locking part and press against the first locking part when the first locking part is inserted into the first locking groove.

[0009] By adopting the above technical solution, when the first locking part is inserted into the first locking groove, multiple second locking parts can press against the first locking part from the periphery of the first locking part, thereby improving the stability of the first locking part.

[0010] Optionally, a driving block is slidably connected in the first locking groove. The moving direction of the driving block is the length direction of the first locking groove. The driving block is rotatably connected to a connecting rod. The connecting rod is rotatably connected to the second locking part. The driving block is used to drive the second locking part to move through the connecting rod when the first locking part is inserted into the first locking groove.

[0011] By adopting the above technical solution, when the first locking part is inserted into the first locking groove, the first locking part can abut against the driving block and push the driving block to slide along the length direction of the first locking groove, so that the driving block drives the connecting rod to rotate, and the connecting rod drives the second locking part to move closer to the first locking part and abut against the first locking part.

[0012] Optionally, the side wall of the first locking part is provided with a second locking groove for the insertion of the second locking part.

[0013] By adopting the above technical solution, the second locking part can be inserted into the second locking groove on the first locking part and abut against the inner wall of the second locking groove, thereby further improving the stability of the first locking part after it is inserted into the first locking groove.

[0014] Optionally, a guide surface inclined to the length direction of the fixed groove is formed at the opening of the first locking groove.

[0015] By adopting the above technical solution, since the space inside the human body is small and it is not convenient for the surgeon to observe the position of the first locking groove, the guide surface makes the opening size of the first locking groove larger than the cross-sectional size of the first locking part, so that the first locking part can be inserted into the first locking groove from the opening of the first locking groove, and the pad can be positioned in the slot.

[0016] Optionally, the pad has multiple limiting grooves around the first locking part on one end face of the tibial prosthesis, and the inner wall of the groove is provided with multiple limiting parts for insertion into the limiting groove.

[0017] By adopting the above technical solution, when the gasket is inserted into the limiting groove, the limiting part is inserted into the corresponding limiting groove, so that the limiting part abuts against the inner wall of the corresponding limiting groove, thereby improving the stability of the connection between the gasket and the limiting groove and facilitating the positioning of the gasket.

[0018] Optionally, the number of the limiting grooves is three, and the three limiting grooves are equally spaced.

[0019] By adopting the above technical solution, the three limiting grooves can not only restrict the movement of the gasket in any direction along a plane, but also facilitate the correspondence between the limiting grooves and the limiting parts.

[0020] Optionally, the outer wall of the tibial prosthesis has an installation groove.

[0021] By adopting the above technical solution, the surgeon first installs the femoral prosthesis onto the femoral base, then installs the tibial prosthesis onto the tibial base, then positions the spacer between the femoral and tibial prostheses, and pushes the spacer into the slot. After opening the installation groove on the outer wall of the tibial prosthesis, it is convenient for the surgeon to insert one side of the special tool forceps into the installation groove, thereby providing a fulcrum for applying force to the spacer when pressing it in, which facilitates the operation of the surgeon.

[0022] Optionally, the tibial prosthesis has a weight-reducing groove.

[0023] By adopting the above technical solution, the weight reduction groove can reduce the weight of the tibial prosthesis, reduce the impact of the tibial prosthesis on the patient, and thus improve the patient's postoperative experience.

[0024] In summary, this application includes at least one of the following beneficial effects: 1. The middle part of the pad is locked to the tibial prosthesis by the first locking part and the first locking groove. When the femoral prosthesis moves relative to the pad, the first locking part bears more force to reduce the force on the edge of the pad, so that the force on the edge and middle of the pad is more even, thereby reducing the deformation and micro-movement of the pad, reducing the wear of the pad caused by deformation and micro-movement, and improving the service life of the unicompartmental knee joint prosthesis. 2. When the first locking part is inserted into the first locking groove, multiple second locking parts can abut against the first locking part from the periphery of the first locking part, thereby improving the stability of the first locking part; 3. The second locking part can be inserted into the second locking groove on the first locking part and abut against the inner wall of the second locking groove, thereby further improving the stability of the first locking part after it is inserted into the first locking groove; 4. The surgeon first installs the femoral prosthesis onto the femoral base, then installs the tibial prosthesis onto the tibial base, and then positions the spacer between the femoral and tibial prostheses and pushes the spacer into the slot. After opening the installation groove on the outer wall of the tibial prosthesis, it is convenient for the surgeon to insert one side of the special tool forceps into the installation groove, thereby providing a fulcrum for applying force to the spacer when pressing it in, which facilitates the operation of the surgeon. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of an embodiment of this application; Figure 2 This is an exploded structural diagram illustrating the first locking groove according to an embodiment of this application; Figure 3 This is an exploded structural diagram illustrating the first locking part according to an embodiment of this application; Figure 4 This is a partial cross-sectional structural diagram of the driving block used in an embodiment of this application.

[0026] Explanation of reference numerals in the attached drawings: 1. Femoral prosthesis; 11. First replacement surface; 12. First abutment surface; 13. First mounting post; 2. Tibial prosthesis; 21. Locking groove; 22. Locking block; 23. Mounting groove; 24. Weight reduction groove; 25. First locking groove; 26. Guide surface; 27. Limiting block; 28. Second abutment surface; 3. Gasket; 31. Second replacement surface; 32. First locking part; 34. Second locking groove; 35. Limiting groove; 4. Elastic element; 5. Connecting rod; 6. Drive block; 7. Second locking part. Detailed Implementation

[0027] The following is in conjunction with the appendix Figure 1-4 This application will be described in further detail.

[0028] When performing a unicompartmental knee arthroplasty, the surgeon first needs to process the patient's femoral and tibial matrices. This involves cutting the femoral and tibial matrices into suitable shapes for installation, drilling installation holes at corresponding positions on the femur, and creating semi-circular installation grooves 23 on the tibia. After processing, the unicompartmental knee prosthesis is installed on the femoral and tibial matrices.

[0029] This application discloses a unicompartmental knee joint prosthesis, referring to... Figure 1 and Figure 2 The unicompartmental knee joint prosthesis includes a femoral prosthesis 1, which is made of cobalt-chromium-molybdenum alloy or titanium alloy. One end of the femoral prosthesis 1 has an arc-shaped first replacement surface 11, and the other end has a continuously bent first mounting surface. The first mounting surface is fixedly connected to a plurality of first mounting posts 13 for insertion into mounting holes.

[0030] In unicompartmental arthroplasty, after the surgeon processes the femoral and tibial bases, the multiple first mounting posts 13 of the femoral prosthesis 1 are inserted one-to-one into the multiple mounting holes of the femur. The femoral prosthesis 1 is then tapped with a tool to make the first mounting posts 13 of the femoral prosthesis 1 engage with the mounting holes and make the first mounting surface abut against the cut surface formed on the femur, thereby installing the femoral prosthesis 1 onto the femur.

[0031] Reference Figure 2 and Figure 3The unicompartmental knee joint prosthesis includes a tibial prosthesis 2, which is made of cobalt-chromium-molybdenum alloy or titanium alloy. The tibial prosthesis 2 is semi-circular plate-shaped. The end face of the tibial prosthesis 2 closest to the tibial base is named the second abutment surface 28. The second abutment surface 28 is fixedly connected to a locking block 22 perpendicular to the tibial prosthesis 2. The locking block 22 is semi-circular plate-shaped. The side wall of the tibial prosthesis 2 has an installation groove 23 and a weight reduction groove 24. The end face of the tibial prosthesis 2 away from the tibial base has a locking groove 21. A gasket 3 is locked in the locking groove 21. The gasket 3 is made of ultra-high molecular weight polyethylene, highly cross-linked ultra-high molecular weight polyethylene, or highly cross-linked ultra-high molecular weight polyethylene mixed with vitamin E.

[0032] In unicompartmental arthroplasty, after the surgeon processes the femoral and tibial mammary bodies, the locking block 22 of the tibial prosthesis 2 is inserted into the semi-circular mounting groove 23 of the tibial mammary body, so that the second abutment surface 28 abuts against the tibial mammary body, thereby fixing the tibial prosthesis 2 to the tibial mammary body. Then, the gasket 3 is inserted between the first abutment surface 12 and the locking groove 21. The surgeon then inserts one end of a special tool forceps into the mounting groove 23 and the other end into the spacer 3 and the first abutment surface 12, and then applies force to the spacer 3 and the tibial mammary body, so that the spacer 3 is locked into the locking groove 21.

[0033] Mounting slot 23 provides a force application point for specialized forceps, facilitating the application of force to the spacer 3 and tibial prosthesis 2 by the surgeon. Weight reduction slot 24 reduces the weight of the tibial prosthesis 2, thereby minimizing its impact on the patient and improving their experience.

[0034] Reference Figure 2 and Figure 4 The tibial prosthesis 2 has a first locking groove 25 on the bottom wall of the slot 21, and three limiting blocks 27 are fixedly connected around the axis of the positioning groove. The three limiting blocks 27 are equally spaced. Near the opening of the first locking groove 25, a guide surface 26 is formed that is inclined to the length direction of the first locking groove 25, so that the diameter of the opening of the first locking groove 25 is larger than the inner diameter of the first locking groove 25. Multiple second locking parts 7 are slidably fitted on the side wall of the first locking groove 25. The second locking parts 7 are rectangular strips, and the movement direction of the second locking parts 7 is perpendicular to the length direction of the first locking groove 25. The multiple second locking parts 7 are equally spaced around the axis of the first locking groove 25. An elastic element 4 is installed on the bottom wall of the first locking groove 25. The elastic element 4 is a spring. The elastic element 4 is fixedly connected to a driving block 6. The driving block 6 is slidably connected to the first locking groove 25 along the axis of the first locking groove 25. A connecting rod 5 connects the driving block 6 and the second locking parts 7.

[0035] Reference Figure 3 and Figure 4The gasket 3 has a first locking part 32 fixedly connected to the middle of the end face near the tibial base, corresponding to the first locking groove 25. The side wall of the first locking part 32 has a plurality of second locking grooves 34 corresponding to the plurality of second locking parts 7. The gasket 3 has three limiting grooves 35 around the axis of the first locking part 32 on the end face near the tibial base, and the three limiting grooves 35 correspond to the three limiting blocks 27.

[0036] When the pad 3 is inserted into the slot 21, the three limiting blocks 27 are simultaneously inserted into the three limiting slots 35 one by one, and the first locking part 32 is inserted into the first locking slot 25, so that the first locking part 32 abuts against part of the inner wall of the first locking slot 25. When the first locking part 32 moves along the length direction of the first locking slot 25, the first locking part 32 abuts against the driving block 6 and pushes the driving block 6 to move closer to the tibial base, so that the elastic element 4 undergoes compression deformation. When the driving block 6 moves, the driving block 6 drives multiple second locking parts 7 to move closer to the first locking part 32 simultaneously through multiple connecting rods 5, so that the second locking parts 7 are inserted into the corresponding second locking slots 34, so that multiple second locking parts 7 simultaneously abut against the inner wall of the second locking slots 34, improving the stability of the pad 3 when it is engaged with the slot 21, thereby making the force on the middle part of the pad 3 and the edge of the pad 3 more balanced when the femoral prosthesis 1 rotates, thereby reducing the micro-movement and deformation of the pad 3, thereby reducing the wear of the pad 3 and improving the service life of the pad 3.

[0037] Since the contact point between the femoral prosthesis 1 and the pad 3 is located in the middle of the pad 3 during movement, and the first locking part 32 is located in the middle of the pad 3, the first locking part 32, the first locking groove 25, the second locking part 7, and the second locking groove 34 can bear more force when the femoral prosthesis 1 moves relative to the pad 3. This reduces the force on the inner wall of the slot 21 and the side wall of the pad 3, improves the uniformity of the force on each part of the pad 3, and reduces the overall deformation and micro-movement of the pad 3, thereby increasing the service life of the pad 3.

[0038] The limiting block 27 and the limiting groove 35 cooperate to make the inner wall of the limiting block 27 abut against the limiting groove 35, thereby improving the stability when the pad 3 and the slot 21 are engaged. The three limiting blocks 27 can restrict the movement of the pad 3 in different directions, thereby reducing the micro-movement and deformation of the pad 3 when the femoral prosthesis 1 rotates, thereby reducing the wear of the pad 3 and increasing the service life of the pad 3. In addition, the number of limiting blocks 27 and limiting grooves 35 is three, which facilitates processing and reduces processing costs.

[0039] The guide surface 26 makes the diameter of the opening of the first locking groove 25 larger than the inner diameter of the first locking groove 25, which facilitates the insertion of the first locking part 32 into the first locking groove 25 and facilitates the positioning of the gasket 3 by the cooperation of the first locking part 32 with the first locking groove 25.

[0040] The implementation principle of a unicompartment knee joint prosthesis in this application embodiment is as follows: the first locking part 32 in the middle of the pad 3 is inserted into the first locking groove 25, which improves the stability of the contact between the pad 3 and the femoral prosthesis 1. When the femoral prosthesis 1 moves relative to the pad 3, the first locking part 32 bears more force to reduce the force on the pad 3, so that the force on the edge and the middle of the pad 3 is more uniform, thereby reducing the deformation and micro-movement of the pad 3, reducing the wear caused by the deformation and micro-movement of the pad 3, and improving the service life of the unicompartment knee joint prosthesis.

[0041] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A unicompartmental knee joint prosthesis, characterized in that: include, Tibial prosthesis (2), wherein a slot (21) is provided on the tibial prosthesis (2), and a first locking groove (25) is provided on the bottom wall of the slot (21); The pad (3) has a first locking part (32) at the middle end facing the tibial prosthesis (2), and the first locking part (32) is used to engage with the first locking groove (25).

2. The unicompartmental knee joint prosthesis according to claim 1, characterized in that: The first locking groove (25) has a plurality of second locking parts (7) slidably connected to its side wall. The moving direction of the second locking parts (7) is perpendicular to the length direction of the first locking groove (25). The second locking parts (7) are used to move closer to the first locking part (32) and press against the first locking part (32) when the first locking part (32) is inserted into the first locking groove (25).

3. A unicompartmental knee joint prosthesis according to claim 2, characterized in that: A drive block (6) is slidably connected in the first locking groove (25). The moving direction of the drive block (6) is the length direction of the first locking groove (25). The drive block (6) is rotatably connected to a connecting rod (5). The connecting rod (5) is rotatably connected to the second locking part (7). The drive block (6) is used to drive the second locking part (7) to move through the connecting rod (5) when the first locking part (32) is inserted into the first locking groove (25).

4. A unicompartmental knee joint prosthesis according to claim 3, characterized in that: The first locking part (32) has a second locking groove (34) on its side wall for the insertion of the second locking part (7).

5. A unicompartmental knee joint prosthesis according to claim 2, characterized in that: The opening of the first locking groove (25) has a guide surface (26) that is inclined to the length direction of the fixing groove.

6. A unicompartmental knee joint prosthesis according to claim 1, characterized in that: The pad (3) has multiple limiting grooves (35) around the first locking part (32) facing one end face of the tibial prosthesis (2), and the inner wall of the slot (21) is provided with multiple limiting parts for insertion into the limiting grooves (35).

7. A unicompartmental knee joint prosthesis according to claim 6, characterized in that: The number of the limiting grooves (35) is three, and the three limiting grooves (35) are equally spaced.

8. A unicompartmental knee joint prosthesis according to claim 1, characterized in that: The tibial prosthesis (2) has an installation groove (23) on its outer wall.

9. A unicompartmental knee joint prosthesis according to claim 1, characterized in that: The tibial prosthesis (2) has a weight-reducing groove (24).

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