Cartilage repair stent

Abstract

A hollow containing cavity is formed in a main body part, a supporting piece is connected with the containing cavity in a matched mode, a channel communicated with the containing cavity is formed in the end, away from the supporting piece, of a connecting part, and one end of a limiting piece enters the connecting part through the channel and is in running fit with the connecting part. The other end of the limiting piece extends out of the support body and is provided with a positioning piece, the positioning piece has a first working state and a second working state, and in the first working state, the positioning piece and the connecting part are arranged in parallel; in the second working state, the positioning piece and the connecting part are arranged at an angle, and the two ends of the positioning piece protrude out of the connecting part respectively. When the stent is implanted into a human body, the positioning piece and the connecting part are in a parallel state, and the whole positioning piece is located in the projection range of the connecting part. After the support is placed into the human body, the positioning piece can be rotated through a special tool, the positioning piece and the connecting part are arranged at an angle, the positioning piece is cut into the cancellous bone, the fixing strength is improved, and the positioning piece is prevented from being disengaged outwards or sinking downwards.

Description

Technical Field

[0001] The utility model relates to the technical field of medical devices, in particular to a cartilage repair bracket. Background Art

[0002] Articular cartilage is a transparent cartilage covering the synovial joints. It not only acts as a fulcrum, but also bears the compression force generated by adjacent joints and muscles. The shear force generated by joint movement will further wear the joint surface, making the articular cartilage vulnerable to damage. However, once the articular cartilage is damaged, its self-healing ability is limited due to its low metabolic characteristics. In the absence of a vascular system, lymphatic vessels and nerve innervation, the articular cartilage lacks a reservoir of stem cells and growth factors. Therefore, the articular cartilage can hardly regenerate itself, and most injuries are irreversible.

[0003] The current bone repair scaffolds are all cylindrical in design. As described in patent application number CN201710023244.5, after the cartilage repair scaffold is implanted in the human body, the scaffold tends to sink under the action of the human body's weight, causing the cartilage repair scaffold to fail because the scaffold is combined with cancellous bone underneath.

[0004] In addition, the commonly used repair techniques such as grinding and shaping, Pride drilling, and microfracture all have the same treatment mechanism of penetrating the subchondral bone plate to allow blood cells, bone marrow mesenchymal stem cells (MSCs), growth factors, proteins, etc. to participate in cartilage repair. The new cartilage tissue formed by repairing the full-thickness defect of cartilage using these technologies is mostly fibrocartilage, and its composition varies greatly. Some are dense fibrous tissues that contain little or no type II collagen. As described in the patent with application number CN201611183811.5, it is composed of a porous salt layer and a porous metal material layer from top to bottom, and the cartilage repair scaffold is a permanent implant device, and the metal material is difficult to remove in subsequent revision surgery, which is not friendly to revision surgery. Utility Model Content

[0005] The utility model aims at the technical problem that a stent may sink, and proposes a cartilage repair stent, which cuts into the cancellous bone through a positioning piece to increase the fixing strength and prevent it from falling out or sinking downward.

[0006] The technical solution adopted by the utility model is as follows: a cartilage repair stent, comprising a stent, a support member and a limit member, the stent comprising a main body and a connecting part integrally formed with the main body, the main body being provided with a hollow cavity, the support member being cooperatively connected with the cavity, an end of the connecting part away from the support member being provided with a channel connected with the cavity, one end of the limit member entering the interior of the connecting part through the channel and rotatably cooperating with the connecting part, the other end of the limit member extending outside the stent body and being provided with a positioning member, the positioning member having a working state one and a working state two, in the working state one, the positioning member is arranged in parallel with the connecting part; in the working state two, the positioning member is arranged at an angle to the connecting part, and the two ends of the positioning member respectively protrude from the connecting part.

[0007] Optionally, the center of the positioning member is connected to the limiting member, a first inclined surface is provided on one side of one end of the positioning member, and a second inclined surface is provided on the other side of the other end of the positioning member.

[0008] Optionally, the limiting member is located at one end of the connecting part and is fixedly connected to a limiting ring, the diameter of the limiting ring is larger than the diameter of the channel, the width of the side surface of the main body is larger than the width of the side surface of the connecting part, and the connection between the main body and the connecting part is an arc-shaped connecting surface.

[0009] Optionally, the connecting portion is provided with a through groove running through both sides, the accommodating cavity, the through groove and the channel are connected in sequence, and the limiting ring is located in the through groove.

[0010] Optionally, the material of the bracket is polyetheretherketone polymer material or polyetherketoneketone polymer material.

[0011] Optionally, the support is a porous structure, the diameter of the rods in the porous structure is 0.1-0.6 mm, the porosity of the porous structure is 40%-60%, the pore size of the porous structure is 200-400 mm, and the distance between the rods in the porous structure is 200-600 mm.

[0012] Optionally, the width of the bracket gradually decreases from the main body toward the connecting portion, and the angle between the main body and the vertical direction is 0.5 to 3 degrees.

[0013] Optionally, the inner wall of the main body is provided with an internal thread, and the outer wall of the support member is provided with an external thread matching the internal thread, and the internal thread and the external thread are respectively solid structures.

[0014] Optionally, the support member includes a porous layer and a threaded layer wrapped around the outer peripheral wall of the porous layer, the threaded layer is provided with the external thread, and the porous layer is provided with a plurality of pores, and the pores penetrate the cavity and are connected with the through groove.

[0015] Optionally, the porosity of the porous layer is 30% to 40%, and the radius ratio of the porous layer to the threaded layer is 1:1.2 to 1.5.

[0016] The beneficial effects of the utility model are as follows: (1) When the stent is implanted in the human body, the positioning member and the connecting portion are parallel to each other, and the positioning member as a whole is within the projection range of the connecting portion. After the stent is placed in the human body, a special tool can be used to rotate the positioning member so that the positioning member and the connecting portion are set at an angle, so that the positioning member cuts into the cancellous bone, increases the fixing strength, and prevents it from falling out or sinking downward. The support member provides support rigidity for the stent.

[0017] (2) Polyetheretherketone (PEEK) polymer material or polyetherketoneketone (PEKK) polymer material not only has an elastic modulus close to that of bone, which can keep the surrounding bone at its original strength, but also has visibility, that is, it can pass through X-rays and does not show up during CT and MRI scans, making it easier to evaluate bone growth and healing processes. In addition, PEEK material also has excellent biocompatibility, and the material modified with hydroxyapatite has more bone-promoting and hydrophilic functions. Compared with metal materials, it is easier to renovate and remove. The external thread of the support is a solid structure, which makes the connection between the support and the bracket more stable and provides support rigidity for the bracket. The porous layer is conducive to the transfer of blood and stem cells in the bone marrow to the cartilage surface through the pores, which is conducive to the rapid growth of bone tissue and shortens the integration period. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of the structure of a cartilage repair stent proposed in an embodiment of the utility model;

[0019] Figure 2 A schematic diagram of a positioning member in working state 1 provided in an embodiment of the utility model;

[0020] Figure 3 A schematic diagram of the positioning member in the second working state provided by the embodiment of the utility model;

[0021] Figure 4 A front view of a cartilage repair stent according to an embodiment of the utility model;

[0022] Figure 5 for Figure 4 Side view of the mid-cartilage repair scaffold;

[0023] Figure 6 This is a schematic diagram of a support member provided in an embodiment of the present utility model.

[0024] The marks in the drawings are: 1. bracket; 11. main body; 12. connecting part; 13. through groove; 14. arc-shaped connecting surface; 2. support member; 21. porous layer; 22. threaded layer; 3. limit member; 31. positioning member; 311. first inclined surface; 312. second inclined surface; 32. limit ring. DETAILED DESCRIPTION

[0025] The present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant utility model, rather than to limit the utility model. It should also be noted that, for ease of description, only the parts related to the utility model are shown in the accompanying drawings. Multiple technical solutions in the same embodiment, and multiple technical solutions in different embodiments, can be arranged and combined to form new technical solutions that do not have contradictions or conflicts, all of which are within the scope of protection required by the present utility model.

[0026] like Figures 1 to 3 As shown, this embodiment discloses a cartilage repair scaffold, including a scaffold 1, a support member 2 and a stopper 3. The scaffold 1 includes a main body 11 and a connecting portion 12 integrally formed with the main body 11. The main body 11 is provided with a hollow cavity, the support member 2 is connected with the cavity, and the end of the connecting portion 12 away from the support member 2 is provided with a channel connected with the cavity. One end of the stopper 3 enters the interior of the connecting portion 12 through the channel and rotates with the connecting portion 12. The other end of the stopper 3 extends outside the main body of the scaffold 1 and is provided with a positioning member 31. The positioning member 31 has a working state 1 and a working state 2. In the working state 1, the positioning member 31 is arranged parallel to the connecting portion 12; in the working state 2, the positioning member 31 is arranged at an angle with the connecting portion 12, and the two ends of the positioning member 31 protrude from the connecting portion 12 respectively. When the scaffold 1 is implanted into the human body, the positioning member 31 is parallel to the connecting portion 12, and the positioning member 31 is entirely within the projection range of the connecting portion 12. After the bracket 1 is placed in the human body, the positioning member 31 can be rotated using a dedicated tool so that the positioning member 31 and the connecting portion 12 are set at an angle, so that the positioning member 31 cuts into the cancellous bone, increases the fixing strength, and prevents it from falling out or sinking downward. The support member 2 provides support rigidity for the bracket 1.

[0027] In this embodiment, if Figure 2 and 3 As shown, the center of the positioning member 31 is connected to the limiting member 3, and a first inclined surface 311 is provided on one side of one end of the positioning member 31, and a second inclined surface 312 is provided on the other side of the other end of the positioning member 31. The first inclined surface 311 makes one side of the positioning member 31 thin-sheet-shaped, and the second inclined surface 312 makes the other side of the positioning member 31 thin-sheet-shaped, so that when the positioning member 31 rotates, the two ends of the positioning member 31 can be more smoothly cut into the cancellous bone.

[0028] In this embodiment, if Figure 5 As shown, the limiting member 3 is located at one end of the connecting portion 12 and is fixedly connected to a limiting ring. The diameter of the limiting ring is larger than the diameter of the channel. The width of the side of the main body 11 is larger than the width of the side of the connecting portion 12. The connection between the main body 11 and the connecting portion 12 is an arc-shaped connecting surface 14. The limiting ring is connected to the limiting member 3 by laser welding, gluing or threading to prevent the limiting member 3 from falling off the channel. The arc-shaped connecting surface 14 is a transition from the main body 11 to the flat-shaped connecting portion 12, and the arc-shaped design of the arc-shaped connecting surface 14 can avoid fracture after implantation caused by stress concentration. At the same time, the arc-shaped connecting surface 14 also prevents the cartilage repair scaffold 1 from sinking. The limiting ring and the positioning member 31 are made of metal, such as titanium alloy. As Figure 4 As shown, the width of the bracket 1 gradually decreases from the main body 11 toward the connecting part 12, and the angle between the main body 11 and the vertical direction is 0.5-3°. The width of the bracket 1 refers to the width of the front of the bracket 1. The bracket 1 has a slight taper design, with a large upper and small lower appearance design, which matches the shape of the knee joint with a large upper and small lower shape. The angle between the main body 11 and the vertical direction can be 0.5°, 1°, 2°, or 3°.

[0029] In this embodiment, if Figure 1 As shown, the connecting portion 12 is provided with a through groove 13 that passes through both sides, the cavity, the through groove 13, and the channel are connected in sequence, and the limit ring is located in the through groove 13. The through groove 13 serves as an observation window, which is convenient for the operator to observe the rotation angle of the limit ring, i.e., the positioning member 31. The limit member 3 and the positioning member 31 can be integrally formed.

[0030] In this embodiment, the bracket 1 is made by a thermoplastic material melt deposition molding 3D printing process or a powder laser sintering 3D printing process, and the material of the bracket 1 is a polyetheretherketone polymer material or a polyetherketoneketone polymer material. Polyetheretherketone (PEEK) polymer material or polyetherketoneketone (PEKK) polymer material not only has an elastic modulus close to that of bone, which can keep the surrounding bone at its original strength, but also has visibility, that is, it can pass through X-rays and does not develop during CT and MRI scans, which makes it easier to evaluate bone growth and healing processes. In addition, PEEK material also has excellent biocompatibility, and the material modified with hydroxyapatite has more bone-promoting and hydrophilic functions. Compared with metal materials, it is easier to renovate and remove. The bracket 1 is a porous structure, and the porous structure is formed by stacking and overlapping each rod to form a three-dimensional porous structure. The diameter of the rod in the porous structure is 0.1-0.6 mm, the porosity of the porous structure is 40%-60%, the pore size of the porous structure is 200-400 mm, and the distance between the rods is 200-600 mm. The three-dimensionally connected porous structure has better biocompatibility, helps blood perfusion, provides growth space for cells, promotes bone growth, does not slip or loosen after implantation, and can be tightly combined with bone tissue. The diameter of the rod in the porous structure can be 0.1 mm, 0.2 mm, 0.4 mm, 0.6 mm, the porosity of the porous structure can be 40%, 50%, 60%, the pore size can be 200 mm, 300 mm, 350 mm, 400 mm, and the distance between the rods can be 200 mm, 300 mm, 400 mm, 500 mm, 600 mm.

[0031] In this embodiment, if Figure 6 As shown, the inner wall of the main body 11 is provided with an internal thread, and the outer peripheral wall of the support member 2 is provided with an external thread matching the internal thread, and the internal thread and the external thread are respectively printed in entity. The depth of the external thread and the depth of the internal thread are both 0.2 to 1 mm. The support member 2 includes a porous layer 21 and a threaded layer 22 wrapped around the outer peripheral wall of the porous layer 21, the threaded layer 22 is provided with an external thread, and the porous layer 21 is provided with a plurality of pores, which penetrate the cavity and communicate with the through groove 13. The material of the support member 2 is peek, and the external thread of the threaded layer 22 is a solid structure, which makes the connection between the support member 2 and the bracket 1 more stable and provides support rigidity for the bracket 1. The porous layer 21 is conducive to the transfer of blood and stem cells in the bone marrow to the cartilage surface through the pores, which is conducive to the rapid growth of bone tissue and shortening the integration period. The porosity of the porous layer 21 is 30% to 40%, and the radius ratio of the porous layer 21 to the threaded layer 22 is 1:1.2 to 1.5. The porosity of the porous layer 21 can be 30%, 35%, or 40%, and the radius ratio of the porous layer 21 to the threaded layer 22 is 1:1.2, 1:1.4, or 1:1.5.

[0032] The above description is only a preferred embodiment of the utility model, and does not limit the patent protection scope of the utility model. Any equivalent structural transformation made using the contents of the utility model specification and drawings, directly or indirectly used in other related technical fields, is also included in the protection scope of the utility model.

Claims

1. A cartilage repair scaffold, characterized in that: The invention comprises a bracket, a supporting member and a limiting member, wherein the bracket comprises a main body and a connecting member integrally formed with the main body, the main body is provided with a hollow cavity, the supporting member is connected with the cavity in cooperation, an end of the connecting member away from the supporting member is provided with a channel connected with the cavity, one end of the limiting member enters the interior of the connecting member through the channel and rotatably cooperates with the connecting member, the other end of the limiting member extends outside the bracket body and is provided with a positioning member, the positioning member has a working state one and a working state two, in the working state one, the positioning member is arranged in parallel with the connecting member; in the working state two, the positioning member is arranged at an angle with the connecting member, and the two ends of the positioning member respectively protrude from the connecting member.

2. The cartilage repair scaffold according to claim 1, characterized in that: The center of the positioning member is connected to the limiting member, a first inclined surface is arranged on one side of one end of the positioning member, and a second inclined surface is arranged on the other side of the other end of the positioning member.

3. The cartilage repair scaffold according to claim 1, characterized in that: The limiting member is located at one end of the connecting portion and is fixedly connected to a limiting ring, the diameter of the limiting ring is larger than the diameter of the channel, the width of the side surface of the main body is larger than the width of the side surface of the connecting portion, and the connection between the main body and the connecting portion is an arc-shaped connecting surface.

4. The cartilage repair scaffold according to claim 3, characterized in that: The connecting portion is provided with a through groove penetrating through two sides, the accommodating cavity, the through groove and the channel are connected in sequence, and the limiting ring is located in the through groove.

5. The cartilage repair scaffold according to claim 1, characterized in that: The material of the bracket is polyetheretherketone polymer material or polyetherketoneketone polymer material.

6. The cartilage repair scaffold according to claim 1, characterized in that: The support is a porous structure, the diameter of the rods in the porous structure is 0.1-0.6 mm, the porosity of the porous structure is 40%-60%, the pore size of the porous structure is 200-400 mm, and the distance between the rods in the porous structure is 200-600 mm.

7. The cartilage repair scaffold according to claim 1, characterized in that: The width of the bracket gradually decreases from the main body toward the connecting part, and the angle between the main body and the vertical direction is 0.5-3°.

8. The cartilage repair scaffold according to claim 4, characterized in that: The inner wall of the main body is provided with an internal thread, and the outer peripheral wall of the support is provided with an external thread matching the internal thread, and the internal thread and the external thread are respectively solid structures.

9. The cartilage repair scaffold according to claim 8, characterized in that: The support member comprises a porous layer and a threaded layer wrapped around the outer peripheral wall of the porous layer, the threaded layer is provided with the external thread, and the porous layer is provided with a plurality of pores, which penetrate through the cavity and communicate with the through groove.

10. The cartilage repair scaffold according to claim 9, characterized in that: The porosity of the porous layer is 30% to 40%, and the radius ratio of the porous layer to the threaded layer is 1:1.2 to 1.5.

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