Ankle joint replacement prosthesis

Abstract

An ankle joint replacement prosthesis comprises a tibia prosthesis assembly and a talus prosthesis, the tibia prosthesis assembly comprises a tibia prosthesis body and a cushion block, the tibia prosthesis body and the cushion block are in an arc shape with the middle bent upwards on the sagittal plane, the cushion block is arranged at the bottom of the tibia prosthesis body in a sleeving mode, and the surface of the upper portion of the tibia prosthesis body is a tibia joint face. The surface of the lower portion of the cushion block is a first articular surface, the surface of the upper portion of the talus prosthesis is a second articular surface, the second articular surface is in an arc shape with the middle bent upwards on a sagittal plane, the surface of the lower portion of the talus prosthesis is a talus joint surface, and the first articular surface is matched with the second articular surface. When the prosthesis is implanted, only the articular cartilage and the subchondral bone need to be treated at the far end of the tibia, so that the bone at the far end of the tibia is reserved to the maximum extent, the anatomical integrity of the bone is guaranteed, the stability of the prosthesis is enhanced, the service life is prolonged, and the clinical operation effect is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of ankle joint replacement, in particular to an ankle joint replacement prosthesis. Background Art

[0002] Joint replacement is a surgical procedure in which one or more articular surfaces of a joint are replaced with a prosthetic articular surface. Ankle replacement is becoming a common treatment for end-stage ankle arthritis. However, because common ankle prostheses currently used clinically require a large amount of distal tibial osteotomy, there is a risk of tibial or fibular fractures during clinical surgery. Furthermore, large osteotomies disrupt the "framework" of the distal tibia, which can reduce the stability of the distal tibial prosthesis and increase the risk of complications such as prosthesis loosening after surgery. This can also shorten the expected service life of the ankle prosthesis. Summary of the Invention

[0003] The purpose of the present invention is to provide an ankle replacement prosthesis that, when implanted, only requires processing of the articular cartilage and subchondral bone of the distal tibia, thereby preserving the distal tibia bone to the greatest extent possible and ensuring its anatomical integrity, thereby helping to enhance the stability of the prosthesis, extend its service life, and improve clinical surgical results.

[0004] The technical solution adopted by the present invention to solve its technical problems is: an ankle joint replacement prosthesis, including a tibial prosthesis component and a talar prosthesis, the tibial prosthesis component including a tibial prosthesis body and a pad, the tibial prosthesis body and the pad are in the shape of an arc with the middle part bent upward on the sagittal plane, the pad is sleeved on the bottom of the tibial prosthesis body, the upper surface of the tibial prosthesis body is the tibial joint surface, the lower surface of the pad is the first joint surface, the upper surface of the talar prosthesis is the second joint surface, the second joint surface is in the shape of an arc with the middle part bent upward on the sagittal plane, the lower surface of the talar prosthesis is the talar joint surface, and the first joint surface and the second joint surface are adapted to each other.

[0005] Preferably, the vertical distance between the highest point of the tibial joint surface and the horizontal plane where the bottoms of the front and rear ends of the pad are located is H1, 5mm≤H1≤8mm.

[0006] Furthermore, a slot with an arc shape in the sagittal plane is provided at the bottom of the tibial prosthesis body, the cross section of the slot in the coronal plane is T-shaped, the front part of the slot is connected to the outside world, and the rear part of the slot is in a closed state; the upper part of the pad is clamped in the slot.

[0007] Furthermore, two first fixing columns are provided in the middle area of ​​the tibial joint surface and are relatively distributed on the left and right sides. The first fixing columns are inclined with the front lower and the rear higher. A first through hole is provided in the first fixing column and is distributed along its axial direction. A second through hole is provided in the upper part of the tibial prosthesis body to realize the connection between the slot and the first through hole.

[0008] Furthermore, a front auxiliary limit plate and a rear auxiliary limit plate are respectively provided at the front and rear parts of the tibial prosthesis body, and the angle between the upper surface of the front auxiliary limit plate and the tibial joint surface is α, 110°≤α≤120°, and two third through holes are provided on the front auxiliary limit plate, which are relatively distributed on the left and right sides, and the angle between the upper surface of the rear auxiliary limit plate and the tibial joint surface is β, 110°≤β≤120°.

[0009] Furthermore, the ankle replacement prosthesis also includes a pad baffle, the upper portion of which is used to connect with the front side wall of the distal end of the tibia, and the lower portion of which is used to prevent the front portion of the pad from moving out of the front portion of the slot.

[0010] Furthermore, two second fixing columns are arranged on the talar joint surface and are relatively distributed on the left and right sides. The second fixing columns are distributed in a state of being higher in the front and lower in the back.

[0011] Furthermore, two fourth through holes are relatively distributed left and right in the middle front area of ​​the tibial prosthesis body, and the fourth through holes are distributed in a state of higher front and lower back. Two fifth through holes are relatively distributed left and right in the front of the second joint surface, and the fifth through holes are distributed vertically.

[0012] Preferably, a porous coating is provided on the tibial joint surface and the talar joint surface, and the first joint surface and the second joint surface are both smooth surfaces.

[0013] The present invention has the following beneficial effects: the upper portion of the pad is disposed within the tibial prosthesis body in a sleeve-type manner, thereby facilitating a reduction in the overall height of the tibial prosthesis component in the sagittal plane. Furthermore, the tibial prosthesis body presents an arcuate structure in the sagittal plane, making it more compatible with the biological structural characteristics of the distal tibial base. Therefore, during replacement surgery, only the distal tibial articular cartilage and subchondral bone need to be processed to ensure the installation and fixation of the tibial prosthesis body at the distal tibial base, thereby maximally preserving the distal tibial bone and ensuring its anatomical integrity, thereby contributing to enhanced prosthesis stability, extended service life, and improved clinical surgical outcomes. When the distal tibia rotates relative to the talus, the limiting action of the front and rear auxiliary limiting plates can improve the movement synchronization between the tibial prosthesis body and the distal tibia, thereby facilitating improved stability of the tibial prosthesis body at the distal tibial base. The limiting action of the pad limiting plate can effectively prevent the pad from detaching from the interior of the tibial prosthesis body, thereby improving the sleeve stability of the pad. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some preferred embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0015] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 is a schematic diagram of the structure of the tibial prosthesis component; Figure 3 Schematic diagram of the structure of the tibial prosthesis body; Figure 4 Schematic diagram of the overall structure of the pad; Figure 5 Schematic diagram of the overall structure of the talar prosthesis; Figure 6 This is a schematic diagram of the state of the present invention being implanted between the tibia and the talus; In the figure: 1 tibial prosthesis component, 11 tibial prosthesis body, 111 tibial joint surface, 112 slot, 113 anterior auxiliary limiting plate, 1131 third through hole, 114 posterior auxiliary limiting plate, 115 first fixing column, 116 second through hole, 117 fourth through hole, 12 pad, 121 first joint surface, 1211 lower convex curved surface, 1212 upper concave curved surface, 2 talar prosthesis, 21 second joint surface, 211 concave curved surface, 212 upper convex curved surface, 22 talar joint surface, 23 second fixing column, 24 fifth through hole, 3 pad baffle, 31 sixth through hole, 32 seventh through hole, 4 distal tibia, 5 talus, 101 first long bone nail, 102 second short bone nail, 103 third short bone nail, 104 fourth short bone nail. DETAILED DESCRIPTION

[0016] The following will be combined with specific embodiments and appendix Figure 1-6 The technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the embodiments described are only some preferred embodiments of the present invention, not all embodiments. Those skilled in the art may make similar modifications without violating the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0017] In the existing field of medical imaging technology, the definitions of the coronal plane and sagittal plane are as follows: Sagittal plane: refers to the longitudinal section in the front-to-back direction that divides the human body into left and right parts. The section is perpendicular to the horizontal plane. The sagittal plane passing through the center of the human body is called the median sagittal plane.

[0018] Coronal plane: also known as the frontal plane, refers to the longitudinal section in the left-right direction that divides the human body into the front and back parts, and is perpendicular to the sagittal plane and the horizontal plane.

[0019] The present invention provides an ankle replacement prosthesis (such as Figure 1As shown), it includes a tibial prosthesis component 1 and a talar prosthesis 2. The tibial prosthesis component includes a tibial prosthesis body 11 and a pad 12. In actual application, the material of the tibial prosthesis body 11 can be titanium alloy or cobalt-chromium alloy, and the material of the pad 12 can be polyethylene. The tibial prosthesis body 11 and the pad 12 are in an arc shape with the middle part bent upward in the sagittal plane. The tibial prosthesis body 11 is in an arc shape with the middle part bent upward, which conforms to the physiological structural characteristics of the bottom of the distal tibia 4. During the replacement surgery, the front bottom and the rear bottom of the distal tibia 4 can be retained to the greatest extent. The structure can realize the preservation of the "frame structure" of the distal tibia 4, and effectively avoid the occurrence of tibial or fibular fractures during the replacement operation; the pad 12 is sleeved on the bottom of the tibial prosthesis body 11, and the upper part of the pad 12 is clamped on the bottom of the tibial prosthesis body 11 in a sleeve manner, which is beneficial to reduce the overall height of the tibial prosthesis component 1 in the sagittal plane as a whole, and then minimize the damage to the bottom of the distal tibia during the replacement operation; the upper surface of the tibial prosthesis body 11 is the tibial joint surface 111. In actual application, the tibial joint surface The tibial prosthesis body 111 is in an arc shape with the middle part of the prosthesis body 11 bent upward on the sagittal plane. When the articular cartilage and subchondral bone at the bottom of the distal tibia 4 are being pressed, the arc-shaped tibial joint surface 111 is also in an arc shape according to the arc structure of the tibial joint surface 111. The arc-shaped tibial joint surface 111 fits into the arc-shaped groove at the bottom of the distal tibia 4, which helps to improve the installation stability of the tibial prosthesis body 11 at the bottom of the distal tibia 4. When the distal tibia 4 rotates, the tibial prosthesis body 11 is relatively stable relative to the tibia. The distal end of the bone 4 will not move easily; the lower surface of the pad 12 is the first joint surface 121, and the upper surface of the talar prosthesis 2 is the second joint surface 21. The second joint surface 21 is an arc shape with the middle part bent upward on the sagittal plane. The lower surface of the talar prosthesis 2 is the talar joint surface 22. In actual application, the talar joint surface 22 is fitted with the bone surface formed after the upper part of the talus 5 is processed. In order to improve the installation stability of the talar prosthesis 2 on the upper part of the talus 5, the talar joint surface 22 can be made into a plane, and the first joint surface 121 and the second joint surface 21 are adapted to each other.The coordination relationship between the first joint surface 121 and the second joint surface 21 is used to simulate the natural ankle joint movement. In order to make the first joint surface 121 and the second joint surface 21 simulate the movement characteristics of the natural ankle joint as much as possible, the first joint surface 121 includes two downward convex curved surfaces 1211 and one upward concave curved surface 1212. In the coronal plane, the upward convex curved surface 1212 is located between the two downward convex curved surfaces 1211. The second joint surface 21 includes two downward concave curved surfaces 211 and one upward convex curved surface 212. In the coronal plane, the upward convex curved surface 212 is located between the two downward concave curved surfaces 211. The downward convex curved surface 1211 and the upward concave curved surface 1212 in the first joint surface 121 correspond to the downward concave curved surface 211 and the upward convex curved surface 212 in the second joint surface 21. In order to improve the relative sliding flexibility of the first joint surface 121 and the second joint surface 21, the first joint surface 121 and the second joint surface 21 are both smooth surfaces.

[0020] In actual application, in order to maximize the protection of the "frame structure" of the distal tibia 4, the articular cartilage and subchondral bone at the bottom of the distal tibia 4 can be processed during the replacement surgery. After processing, a space of approximately 9 mm in height can be obtained. The vertical distance between the highest point of the tibial joint surface 111 and the horizontal plane where the bottom of the front and rear ends of the pad 12 are located is H1. In order to facilitate the smooth installation of the tibial prosthesis body 22 at the bottom of the distal tibia 4, 5mm≤H1≤8mm can be made. Specifically, H1 can be made 7mm. When H1 is 7mm, the overall structural strength of the tibial prosthesis body 11 can meet the use requirements.

[0021] On the basis of the above embodiment, the specific implementation method of the pad 12 being sleeved in the tibial prosthesis body 11 is as follows: a slot 112 in an arc shape on the sagittal plane is provided at the bottom of the tibial prosthesis body 11, the cross section of the slot 112 in the coronal plane is T-shaped, the front portion of the slot 112 is connected to the outside world, and the rear portion of the slot 112 is in a closed state; the upper portion of the pad 12 is clamped in the slot 112, and the opening at the front of the slot 112 is used to facilitate the pad 12 to be moved along the It is smoothly pushed into the slot 112 along the bending direction of the slot 112, and the baffle at the rear of the slot 112 can effectively prevent the pad 12 from moving out from the rear of the slot 112; further, in order to effectively prevent the pad 12 from moving out from the front of the slot 112, the ankle replacement prosthesis also includes a pad baffle 3, the upper part of the pad baffle 3 is used to connect with the front side wall of the distal end of the tibia, and the lower part of the pad baffle 3 is used to prevent the front part of the pad 12 from moving out from the front of the slot 112.

[0022] On the basis of the above embodiment, a specific implementation method for fixing the tibial prosthesis body 11 to the lower part of the distal tibia 4 is as follows: two first fixing posts 115 are provided in the middle area of ​​the tibial joint surface 111, and the first fixing posts 115 are arranged in a tilted state with the front lower and the rear higher. A first through hole is provided in the first fixing post 115 along the axial direction thereof. A second through hole 116 is provided in the upper part of the tibial prosthesis body 11 to connect the locking groove 112 with the first through hole. The two first fixing posts 115 are arranged in the middle area of ​​the tibial joint surface 111 and are arranged in a state with the front lower and the rear higher. This facilitates appropriately lengthening the length of the first fixing posts 115 and smoothly installing the tibial prosthesis body 11 to the lower part of the processed distal tibia 4. At the same time, a longer first long bone nail 101 can be used in the first fixing post 115 to fix the tibial prosthesis body 11 to the distal tibia 4, thereby improving the fixed installation of the tibial prosthesis body 11 on the distal tibia 4. In order to prevent the lower end of the first long bone nail 101 from obstructing the spacer 12 from sliding smoothly into the slot 112, a step is provided at the intersection of the first through hole and the second through hole 116. The first long bone nail 101 is limited by the step. At the same time, the end of the first long bone nail 101 is completely located in the first through hole.

[0023] On the basis of the above embodiment, in order to further improve the stability of the tibial prosthesis body 11 at the bottom of the distal tibia 4, a front auxiliary limiting plate 113 and a rear auxiliary limiting plate 114 are respectively provided at the front and rear parts of the tibial prosthesis body 11. The angle between the upper surface of the front auxiliary limiting plate 113 and the tibial joint surface 111 is α, 110°≤α≤120°. The above range of α is designed based on the structural characteristics of the intersection of the bottom side and the front side of the distal tibia 4. In this specific embodiment, The value of α is set to 115°, and two third through holes 1131 relatively distributed on the left and right are provided on the front auxiliary limiting plate 113. The front auxiliary limiting plate 113 can be fixed on the distal end 4 of the tibia by means of bone screws. The angle between the upper surface of the rear auxiliary limiting plate 114 and the tibial joint surface 111 is β, 110°≤β≤120°. The above range of β is designed based on the structural characteristics of the intersection of the bottom side and the rear side of the distal end 4 of the tibia. In this specific embodiment, the value of β can be set to 115°. On the basis of the above embodiments, in order to facilitate the fixation of the pad baffle 3 on the distal tibia 4, the pad baffle 3 is made into a V-shaped structure, and two sixth through holes 31 relatively distributed on the left and right are provided on the upper part of the pad baffle 3, and two seventh through holes 32 relatively distributed on the left and right are provided on the lower part of the pad baffle 3. After a fourth bone screw 104 passes through the sixth through hole 31, it is fixed on the front wall of the distal tibia 4 to achieve the fixation of the upper part of the pad baffle 3. After a fourth bone screw 104 passes through the seventh through hole 32 and the corresponding third through hole 1131, it is fixed on the lower part of the front wall of the distal tibia 4 to achieve the fixation of the lower part of the pad baffle 3 and the front auxiliary limiting plate 113.

[0024] On the basis of the above embodiment, in order to facilitate the fixed installation of the talar prosthesis 2 on the talus 5, two second fixing columns 23 are provided on the talar joint surface 22 and are relatively distributed on the left and right. The second fixing columns 23 are distributed in a state of being higher in the front and lower in the back. The second fixing columns 23 are in the above-mentioned inclined state, which facilitates the fixed installation of the talar prosthesis 2 on the upper part of the talus 5 in a limited space.

[0025] On the basis of the above embodiment, in order to further improve the installation stability of the tibial prosthesis body 11 and the talar prosthesis 2, two fourth through holes 117 relatively distributed on the left and right are provided in the front middle area of ​​the tibial prosthesis body 11, and the fourth through holes 117 are distributed in a state of high front and low back, and the fourth through hole 117 is a countersunk hole. A second short bone screw 102 is inserted into the fourth through hole 117, and the second short bone screw 102 is used to assist in the fixed installation of the tibial prosthesis body 11 on the distal end of the tibia 4; two fifth through holes 24 relatively distributed on the left and right are provided in the front part of the second joint surface 21, and the fifth through holes 24 are distributed in a vertical state, and the fifth through hole 24 is a countersunk hole. A third short bone screw 103 is inserted into the fifth through hole 24, and the third short bone screw 103 is used to assist in the fixation of the talar prosthesis 2 on the upper part of the talus 5.

[0026] In order to further improve the bonding stability between the tibial bonding surface 111 and the bottom bone surface of the distal tibia 4, and the bonding stability between the talar bonding surface 22 and the upper bone surface of the talus, a porous coating is provided on the tibial bonding surface 111 and the talar bonding surface 22. The surface of the porous coating is rough, which can improve the bonding stability between the bonding surface and the bone surface. Furthermore, a porous coating can also be provided on the surface of the first fixing column 115 and the second fixing column 22. The porous coating can be a metal sintered porous coating, a plasma-sprayed metal porous coating, or a plasma-sprayed calcium phosphate coating.

[0027] In the present invention, "front", "back", "up", "down", "left" and "right" are relative positions used to conveniently describe positional relationships, and therefore cannot be understood as absolute positions to limit the scope of protection.

[0028] Except for the technical features described in the specification, all other technical features are known technologies to those skilled in the art.

[0029] The above description, in conjunction with the accompanying drawings, details the preferred embodiments and examples of the present invention. However, the present invention is not limited to the above embodiments and examples. A person skilled in the art can make several improvements and modifications without departing from the concept of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An ankle replacement prosthesis, characterized in that: The invention comprises a tibial prosthesis component and a talar prosthesis, wherein the tibial prosthesis component comprises a tibial prosthesis body and a pad. The tibial prosthesis body and the pad are in an arc shape with the middle part bent upward in the sagittal plane. The pad is sleeved on the bottom of the tibial prosthesis body. The upper surface of the tibial prosthesis body is the tibial joint surface, the lower surface of the pad is the first joint surface, the upper surface of the talar prosthesis is the second joint surface, the second joint surface is in an arc shape with the middle part bent upward in the sagittal plane, the lower surface of the talar prosthesis is the talar joint surface, and the first joint surface and the second joint surface are adapted to each other.

2. The ankle replacement prosthesis according to claim 1, wherein: The vertical distance between the highest point of the tibial joint surface and the horizontal plane where the bottoms of the front and rear ends of the pad are located is H1, 5mm≤H1≤8mm.

3. The ankle replacement prosthesis according to claim 2, wherein A slot with an arc shape in the sagittal plane is provided at the bottom of the tibial prosthesis body. The cross section of the slot in the coronal plane is T-shaped. The front of the slot is connected to the outside world, and the rear of the slot is closed. The upper part of the pad is clamped in the slot.

4. The ankle replacement prosthesis according to claim 3, wherein Two first fixing columns are arranged in a left and right relative distribution in the middle area of ​​the tibial joint surface. The first fixing columns are inclined with the front lower and the rear higher. A first through hole is arranged in the first fixing column along its axial direction. A second through hole is arranged in the upper part of the tibial prosthesis body to realize the connection between the slot and the first through hole.

5. The ankle replacement prosthesis according to claim 3, wherein A front auxiliary limit plate and a rear auxiliary limit plate are respectively provided at the front and rear of the tibial prosthesis body, the angle between the upper surface of the front auxiliary limit plate and the tibial joint surface is α, 110°≤α≤120°, and two third through holes are provided on the front auxiliary limit plate, which are relatively distributed on the left and right. The angle between the upper surface of the rear auxiliary limit plate and the tibial joint surface is β, 110°≤β≤120°.

6. The ankle replacement prosthesis according to claim 3, wherein: The ankle replacement prosthesis also includes a spacer block baffle, the upper portion of which is used to connect with the front side wall of the distal end of the tibia, and the lower portion of which is used to prevent the front portion of the spacer from moving out of the front portion of the slot.

7. The ankle replacement prosthesis according to claim 3, wherein The talus joint surface is provided with two second fixing posts that are relatively distributed on the left and right sides, and the second fixing posts are distributed in a state of being higher in the front and lower in the back.

8. The ankle replacement prosthesis according to claim 3, wherein Two fourth through holes are arranged in the front middle area of ​​the tibial prosthesis body, which are relatively distributed on the left and right, and the fourth through holes are distributed in a state of higher front and lower back. Two fifth through holes are arranged in the front of the second joint surface, which are relatively distributed on the left and right, and the fifth through holes are distributed in a vertical state.

9. The ankle replacement prosthesis according to claim 1, wherein: A porous coating is provided on the tibial joint surface and the talar joint surface, and the first joint surface and the second joint surface are both smooth surfaces.

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