Tibial prosthesis of artificial knee joint
By applying a porous titanium coating and an absorbable bone cement layer on the connection part of the tibial prosthesis, the problem of unstable fixation of the tibial prosthesis in patients with cancellous bone is solved, and the full fixation of the tibial prosthesis in the body of cancellous bone patients is achieved.
Patent Information
- Application Number
- CN202421179480.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-28
- Publication Date
- 2025-04-08
- Estimated Expiration
- 2034-05-28
AI Technical Summary
The existing tibial prosthesis is unstable in the body of patients with cancellous bones, and initial fixation requires biological interlocking of porous titanium coating, which is slow and cannot meet the early stable fixation needs of tibial prosthesis.
The surface of the connecting portion of the tibial prosthesis is coated with a first coat porous titanium coating and a second coat absorbable bone cement layer. The second coat is located on the first coat. The immediate stable fixation of the tibial prosthesis is achieved through the absorbable bone cement. The porous titanium coating promotes the growth of bone cells and achieves biological interlocking fixation.
The full fixation of the tibial prosthesis in the body of patients with cancellous bones is achieved. Through the absorption of resorbable bone cement and the biological interlocking of porous titanium coating, the initial fixation of the tibial prosthesis is not only met, but also achieved stable biointerlocking fixation in the later stage.
Smart Images
Figure CN222723177U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of artificial knee joints, and more specifically to a tibial prosthesis of an artificial knee joint. Background Art
[0002] The artificial knee joint mainly includes: femoral condyle prosthesis, tibial pad, and tibial prosthesis. The tibial prosthesis is implanted on the patient's tibia, and then the tibial pad is placed on the tibial prosthesis. The femoral condyle prosthesis is implanted on the patient's femur, and the condylar surface of the femoral condyle abuts against the tibial pad. This has become a commonly used operation in clinical practice and has achieved remarkable success in the treatment of knee joint diseases.
[0003] The current fixation of tibial prosthesis and tibia: a porous coating is coated on the column and keel wing of the tibial prosthesis inserted into the tibia, and the keel wing and the column are fixed to the tibia by press-fit, wherein the tibial prosthesis and the tibia are fixed by press-fit to meet the initial fixation of the prosthesis and the tibia, and the porous coating is coated on the tibia to meet the long-term fixation of the prosthesis and the tibia, thereby achieving stable fixation of the tibial prosthesis and the tibia.
[0004] The above fixation methods have the following problems: the tibial prosthesis needs to be press-fitted when implanted, which requires the patient to have good bone conditions, which is very unfriendly to patients with cancellous bones; in addition, the porous titanium coating of the tibial prosthesis grows into the bone tissue, and complete biological interlocking requires 3 months. Before the bone tissue and the porous surface of the tibial prosthesis are completely biologically interlocked, the tibial prosthesis must be stably fixed to the tibia in the early stage, that is, the tibial prosthesis needs to be initially fixed.
[0005] Therefore, it is necessary to develop a tibial prosthesis that has low requirements on the patient's bone quality. Summary of the invention
[0006] The utility model aims to provide a tibial prosthesis which has low requirements on the bone quality of patients and can be fixed in the early stage and in the long term, so that the tibial prosthesis can be fixed reliably in the whole process in the body of a patient with cancellous bone.
[0007] The technical solution provided by the utility model is as follows: the prior art tibial prosthesis is improved, a first coating porous titanium coating is coated on the surface of the connection part of the tibial prosthesis connected with the tibia, and a second coating absorbable bone cement layer is coated on the connection part close to the tibial plate end, and the second coating is located on the first coating. Specifically, a tibial prosthesis of an artificial knee joint comprises:
[0008] a tibial plate having an upper surface for receiving a tibial pad and a lower surface for engaging a tibial surface;
[0009] A connecting portion with a shape of being larger at the top and smaller at the bottom for insertion into the tibia, wherein the large end of the connecting portion is connected to the lower surface, and the connecting portion near the tibial plate end gradually decreases along its length direction, and the outer surface of the connecting portion is coated with a first coating porous titanium coating, and the connecting portion near the tibial plate end is coated with a second coating absorbable bone cement layer, and the second coating is located on the first coating.
[0010] By coating the outer layer of the connection part near the end of the tibial plate with absorbable bone cement and the inner layer with porous titanium coating, the absorbable bone cement can achieve immediate stable fixation of the tibial prosthesis, and the complete absorption period of the absorbable bone cement is 3 months, which can meet the initial fixation of the tibial prosthesis. During the absorption of the absorbable bone cement by the human body, the porous titanium coating can induce bone cells to grow into the porous inner connecting channel and extend and interweave, so as to achieve the biological interlocking fixation of the bone and the tibial prosthesis, thereby achieving the late fixation of the tibial prosthesis. At the same time, the absorbable bone cement is pre-coated on the connection part, so that the connection part does not need to be fixed on the tibia in a press-fit manner, and the tibial prosthesis is fixed on the tibia with bone cement, which has low requirements on the patient's bone quality and can be applied to people with different bone qualities. The complete bone ingrowth time of the porous titanium coating and the complete absorption period of the absorbable bone cement are both 3 months, which can achieve the simultaneous absorption of bone cement and bone ingrowth, and finally achieve initial fixation and late fixation.
[0011] A preferred embodiment further includes a bone cement separator, which is matchedly sleeved on the middle part of the connecting part, and its outer diameter is smaller than the maximum outer diameter of the connecting part. Taking the upper surface of the bone cement separator as the boundary, the upper connecting part is a double-layer coating, and the lower connecting part is a single-layer coating.
[0012] By arranging a bone cement separator on the connection part, the bone cement is prevented from flowing into the tibial medullary cavity which does not need to be filled with bone cement, and at the same time, it has a boundary function, so that the interface between the bone cement layer and the porous titanium coating is flush.
[0013] In a preferred embodiment, a through hole is provided in the middle of the bone cement separator for the column to pass through, and the shape of the bone cement separator is a four-pointed star. The four-pointed star design has an anti-rotation effect.
[0014] In a preferred embodiment, the connecting portion includes a column and a keel wing, the column is vertically connected to the lower surface of the tibial plate, the keel wing is arranged at the connection between the column and the tibial plate, connected to the lower surface and the column, and the bone cement separator is sleeved on the column.
[0015] In a preferred embodiment, the keel wing is in a triangular shape.
[0016] In a preferred embodiment, there are two keel wings, which are arranged on both sides of the column.
[0017] In a preferred embodiment, the keel wing is detachably connected to the tibial plate or is integrally connected to the tibial plate.
[0018] In a preferred embodiment, the keel wing is detachably connected to the column or is integrally connected to the column. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 is a schematic structural diagram of a tibial prosthesis according to an embodiment;
[0020] Figure 2 for Figure 1 Bottom view of
[0021] Figure 3 A schematic diagram of the structure of a tibial prosthesis according to another embodiment
[0022] Figure 4 is a schematic diagram of the structure of a bone cement separator;
[0023] Figure 5 Front view of the bone cement separator.
[0024] In the figure, a tibial prosthesis 1 , a tibial plate 2 , an upper surface 21 , a lower surface 22 , a connecting portion 3 , a column 31 , a keel wing 32 , a bone cement separator 4 , and a through hole 41 are shown. DETAILED DESCRIPTION
[0025] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.
[0026] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.
[0027] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.
[0028] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0029] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.
[0030] like Figure 1-2 As shown, this embodiment is an improvement on the existing tibial prosthesis, a tibial prosthesis 1 for an artificial knee joint, comprising: a tibial plate 2 and a connecting portion 3 in a shape of being larger at the top and smaller at the bottom, the size and shape of the tibial plate 2 being set to be placed on the proximal end of the patient's tibia, the tibial plate 2 having an upper surface 21 for placing a tibial pad, and a lower surface 22 for engaging the tibial surface; the connecting portion 3 is used to be inserted into the tibia, the large end of the connecting portion 3 is connected to the lower surface 22, the connecting portion 3 near the end of the tibial plate 2 gradually decreases along its length direction, and the connecting portion 3 away from the end of the tibial plate 2 is smaller, the surface of the connecting portion 3 engaging with the tibia is coated with a first coating porous titanium coating, and the connecting portion 3 near the end of the tibial plate 2 is coated with a second coating absorbable bone cement layer, and the second coating is located on the first coating. By applying a segmented coating on the connecting portion 3, the bone cement coating can enable the connecting portion 3 near the end of the tibial plate 2 to be immediately fixed to the tibia, thereby achieving initial fixation, and then the connecting portion 3 away from the end of the tibial plate 2 is biologically interlocked and fixed, and finally the connecting portion 3 near the end of the tibial plate 2 is biologically interlocked and fixed again. The biological interlocking fixation can meet the late fixation (also called long-term fixation) of the tibial prosthesis 1, and finally achieve full fixation of the tibial prosthesis 1 in the human body.
[0031] In order to make the interface between the bone cement layer and the porous titanium coating flush, Figure 3-4As shown, a bone cement separator 4 made of ultra-high molecular weight polyethylene is sleeved in the middle of the connecting part 3, and the bone cement separator 4 and the connecting part 3 match each other. The outer diameter of the bone cement separator 4 is smaller than the maximum outer diameter of the connecting part 3. The upper connecting part 3 is a double-layer coating, the inner layer is a porous titanium coating, and the outer layer is an absorbable bone cement layer, and the lower connecting part 3 is a single-layer coating, which is a porous titanium coating. Specifically, a through hole 41 is provided in the middle of the bone cement separator 4 for the column 31 to pass through, and the appearance of the bone cement separator 4 is a four-pointed star (such as Figure 5 as shown).
[0032] In order to further optimize the above technical solution, the connecting part 3 includes a column 31 and a keel wing 32, the column 31 is vertically connected to the lower surface 22 of the tibial plate 2, the keel wing 32 is arranged at the connection between the column 31 and the tibial plate 2, the keel wing 32 is connected to the lower surface 22 and the column 31, and the bone cement separator 4 is sleeved on the column 31, and can be in contact with or not in contact with the keel wing 32. Specifically, there are two keel wings 32, which are arranged on both sides of the column 31, and the keel wings 32 are similar to a triangle shape.
[0033] In order to further optimize the above technical solution, the keel wing 32 is detachably connected or integrally connected to the tibial plate 2. When the keel wing 32 is detachably connected to the tibial plate 2, the keel wing 32 abuts against the tibial plate 2.
[0034] In order to further optimize the above technical solution, the keel wing 32 is detachably connected or integrally connected to the column 31. When the keel wing 32 is detachably connected to the column 31, the keel wing 32 is threadedly connected to the column 31.
[0035] Before use, the connection part 3 of the tibial prosthesis 1 has been coated with a porous titanium coating. During the operation, the tibial medullary cavity is first arranged, and then an absorbable bone cement layer is applied to the connection part 3, and then the connection part 3 is inserted into the tibia. When the bone cement separator 4 is put on the connection part 3, the bone cement separator 4 is first put on the column 31, and then the connection part 3 above the bone cement separator 4 is coated with absorbable bone cement, and then the tibial medullary cavity is filled with additional absorbable bone cement. The absorbable bone cement can enhance the bonding strength with the connection part 3 in the early postoperative period, and at the same time, the absorbable bone cement can play a role in reinforcing and supporting the proximal bone surface of the tibia, fully ensuring the initial postoperative fixation of the tibial prosthesis 1. The porous titanium coating of the connection part 3 is conducive to the formation of the attached bone tissue and the cortical bone bridge, realizing biological interlocking fixation, and ensuring good bone ingrowth and late fixation before the absorbable bone cement is completely absorbed.
[0036] In short, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.
Claims
1. A tibial prosthesis for an artificial knee joint, characterized in that: include: a tibial plate having an upper surface for receiving a tibial pad and a lower surface for engaging a tibial surface; A connecting portion with a shape of being larger at the top and smaller at the bottom for insertion into the tibia, wherein the large end of the connecting portion is connected to the lower surface, and the connecting portion near the tibial plate end gradually decreases along its length direction, and the outer surface of the connecting portion is coated with a first coating porous titanium coating, and the connecting portion near the tibial plate end is coated with a second coating absorbable bone cement layer, and the second coating is located on the first coating.
2. The tibial prosthesis of an artificial knee joint according to claim 1, characterized in that: It also includes a bone cement separator, which is matched and sleeved on the middle part of the connecting part. Its outer diameter is smaller than the maximum outer diameter of the connecting part. Taking the upper surface of the bone cement separator as the boundary, the upper connecting part is a double-layer coating, and the lower connecting part is a single-layer coating.
3. The tibial prosthesis of an artificial knee joint according to claim 2, characterized in that: The connecting part includes a column and a keel wing, the column is vertically connected to the lower surface of the tibial plate, the keel wing is arranged at the connection between the column and the tibial plate, connected to the lower surface and the column, and the bone cement separator is sleeved on the column.
4. The tibial prosthesis of an artificial knee joint according to claim 3, characterized in that: A through hole is provided in the middle of the bone cement separator for the column to pass through, and the shape of the bone cement separator is a four-pointed star.
5. The tibial prosthesis of an artificial knee joint according to claim 3, characterized in that: The keel wing is in a triangle shape.
6. The tibial prosthesis of an artificial knee joint according to claim 5, characterized in that: There are two keel wings, which are arranged on both sides of the column.
7. The tibial prosthesis of an artificial knee joint according to claim 6, characterized in that: The keel wing is detachably connected to the tibial plate or integrally connected thereto.
8. The tibial prosthesis of an artificial knee joint according to claim 6, characterized in that: The keel wing is detachably connected to the column or integrally connected thereto.