Cartilage repair components

Abstract

The present invention relates to a prosthesis for implanting in bone tissue. The present invention specifically discloses a cartilage repair component, comprising: a base and a cap; the base comprises a core body and a surface portion covering the outside of the core body; the surface portion and the core body are respectively configured with a plurality of first pores and second pores for guiding the radial growth of osteoblasts; the surface portion comprises a multi-layer cylindrical mesh that is overlapped with each other, the grids in each layer of mesh serve as the first pores, and the outer shape of the grids of the mesh is configured into a rhombus, and two of the relative vertices of the grid are located in the axial direction, and the other two relative vertices are located in the circumferential direction, and the angles of the two vertices in the axial direction are smaller than the angles of the two vertices in the circumferential direction, so that the mesh can generate radial expansion, so that after the osteoblasts of the lower bone grow toward the base and enter the first pores of the surface portion, the force on the mesh generated by the proliferation and growth of the osteoblasts in the surface portion causes the mesh to expand and radially invade the lower bone.

Description

Technical Field

[0001] The present invention relates to a bone tissue implant, in particular to an implant which enters into bone tissue from a bone joint surface to repair joint surface cartilage. Background Art

[0002] The incidence of osteoarthritis, caused by factors such as age, autoimmune diseases, heavy weight-bearing, and trauma, is high. Osteoarthritis not only causes acute and chronic pain but also damages and injures related bone tissue, including the cartilage on the surface of the joint and the underlying bone on the inner surface of the joint. Damage and injure include thinning of the cartilage layer, regional cartilage loss, and osteoporosis of the underlying bone. Nutrients such as glucosamine are ineffective in treating the pain and bone damage caused by arthritis. Nonsteroidal anti-inflammatory drugs such as ibuprofen and diclofenac sodium have been shown to be effective in relieving pain by inhibiting autoinflammatory responses. However, these drugs have difficulty inhibiting the progression of bone damage, particularly cartilage damage, due at least in part to the lack of nutrient-supplying tissues such as blood vessels in cartilage, which prevents the cartilage from self-repair and, therefore, irreversible damage. When bone tissue is damaged to the point where it can no longer maintain joint function, the traditional medical treatment is joint replacement to restore joint function. However, joint replacement comes with many adverse consequences, such as only partial restoration of joint function, the need for maintenance and repair of the joint prosthesis, and high surgical and repair costs.

[0003] Repairing damaged cartilage before osteoarthritis causes bone loss to the point where joint replacement is necessary can delay or even avoid joint replacement, and can help maintain long-term joint motion and alleviate pain. Cartilage transplantation, as a cartilage repair technique, has been shown to be more effective than medication and other surgical methods (eg, microfracture repair of cartilage and underlying bone) in treating arthritis associated with cartilage damage.

[0004] Cartilage transplantation technology includes three typical techniques. The first technique is to implant pre-cultured autologous chondrocytes into the damaged cartilage area and then cover it with autologous periosteum. The second technique is to remove the damaged cartilage and drill a hole in the damaged cartilage area, and insert autologous bone (usually columnar, the autologous bone is usually called autologous bone plug or autologous bone plug) taken from other joints of the patient, including the underlying bone and cartilage, into the drilled hole. The third technique is to prefabricate allogeneic bone plugs, which include a base and a cap attached to each other. The base can be an allogeneic bone with many holes processed. The bone can also be a prosthetic bone with numerous holes processed by 3D printing or laser engraving of biocompatible high molecular polymers, alloys and other materials. Chondrocytes are pre-implanted in the cap. During the operation, the damaged cartilage is removed and the area where the damaged cartilage is located is drilled. The base is inserted into the drilled hole. The cap corresponds to the cartilage layer to fill the cartilage, and the base corresponds to the underlying bone to fill the underlying bone. After the operation, the chondrocytes proliferate and grow to form new cartilage, and the underlying bone corresponding to the base (i.e., the host bone) grows toward the base and enters the hole in the base to anchor the base.

[0005] The third cartilage transplantation technology has the following advantages over the first two cartilage transplantation technologies: in the first technology, the transplanted chondrocytes can easily migrate from the lesion area to the non-lesion area, while in the third technology, the cap of the allogeneic bone plug acts as a host for chondrocytes and has a certain inhibitory effect on cell migration; in the second technology, the autologous bone is taken from the bone tissue of other joints of the patient, thus causing trauma to the patient's other joints, while in the third technology, the base and cap of the allogeneic bone plug are not from the autologous and / or living body. In addition, 3D printing and laser engraving can be used to obtain bone plugs with diverse structures.

[0006] However, the therapeutic effect of allogeneic bone plugs is not considered perfect. In the existing technology, this technology has the following shortcomings:

[0007] 1. The final fusion effect between the underlying bone (host bone) and the base is poor, specifically manifested in the inability to fuse well in the area between the host bone and the base. The reason for the poor fusion is that the periphery of the base cannot exert sufficient and reasonable mechanical stimulation on the host bone to induce osteoblast proliferation and growth, resulting in osteoporosis in the adjacent area. Even bone edema may occur in this area in the early recovery period after the completion of the operation.

[0008] In the prior art, improvements have been made to allogeneic bone plug transplantation techniques to address the problem of poor fusion between the base and the host bone. However, the improved results are still poor. For example, multiple circumferentially arranged expansion flaps and a tapered hole surrounded by the expansion flaps are machined on the base. During surgery, after the base is inserted into the drilled hole, a pin is inserted into the tapered hole to force the base to expand so that the periphery of the base is tightly integrated with the host bone. Although this improved method improves the final fusion effect, the effect is still insufficient. This is because this method only stimulates the bone in the early stages of surgical recovery and cannot form long-term stimulation. In addition, during surgery, excessive expansion of the base may cause bone collapse or even bone fracture, and bone collapse in turn causes subsequent osteoporosis. For another example, U.S. Patent Publication No. US2013 / 0325126A1 discloses a patented technology, specifically: before the base is inserted into the host bone, a curable fluid such as bone cement is injected into the host bone. After the base is inserted into the host bone, the fluid solidifies to fill the gap between the base and the host bone. However, the solidified substance creates a barrier that is not conducive to the growth of bone cells.

[0009] 2. Chondrocytes transplanted into the cap are still easy to migrate, and the proliferation and growth environment is not good. For example, in the prior art, chondrocytes are hosted by configuring micro-pits on the top surface of the cap. However, chondrocytes easily migrate from the micro-pits. Summary of the Invention

[0010] In response to the above-mentioned technical problems existing in the prior art, an embodiment of the present invention provides a cartilage repair component.

[0011] To solve the above technical problems, the technical solutions adopted in the embodiments of the present invention are:

[0012] A cartilage repair component comprises: a base portion for inserting into a bone hole in a resection area of ​​a joint surface where damaged cartilage has been removed for fusing with underlying bone, and a cap portion for filling the resection area after the base portion is inserted into the bone hole and for receiving chondrocytes;

[0013] The base includes a columnar core body and a surface layer covering the core body; the surface layer and the core body are respectively configured with a plurality of first pores and a plurality of second pores for guiding the radial growth of osteoblasts;

[0014] The surface portion includes multiple layers of tubular mesh that are overlapped with each other, and the grid in each layer of the mesh serves as the first pore. The shape of the grid of the mesh is configured into a rhombus, and two of the relative vertices of the grid are located in the axial direction, and the other two relative vertices are located in the circumferential direction, and the angles of the two axial vertices are smaller than the angles of the two circumferential vertices, so that the mesh can expand radially. Therefore, after the osteoblasts of the underlying bone grow toward the base and enter the first pore of the surface portion, the force exerted on the mesh by the proliferation and growth of the osteoblasts in the surface portion causes the mesh to expand and radially invade the underlying bone.

[0015] Preferably, the expansion stiffness of each layer of mesh in the surface portion is configured such that the expansion stiffness of the mesh in the outer layer is smaller than the expansion stiffness of the mesh in the inner layer.

[0016] Preferably, the grid of the mesh is surrounded by cross-interconnected first edge bars, and the expansion stiffness of the outer layer mesh is made smaller than the expansion stiffness of the inner layer mesh by making the width of the first edge bars of the grid of the outer layer mesh smaller than the width of the first edge bars of the grid of the inner layer mesh.

[0017] Preferably, the grid includes first grids and second grids that are alternately arranged circumferentially in a column manner; the first grids on each layer of the mesh are opposite to each other, and the second grids on each layer of the mesh are opposite to each other; wherein:

[0018] From the outer layer to the inner layer, the area enclosed by the first grid of the mesh decreases, and the area enclosed by the second grid of the mesh increases;

[0019] A radially protruding induction component is fixed on the first edge rod of the mesh located in the inner layer, and the induction component radially passes through the second grid of the mesh located in the outer layer.

[0020] Preferably, the inducing component includes a second edge bar, which is bent to form a wave structure. The second edge bar is axially arranged in the column where the second grid of the mesh is located, and each two adjacent troughs of the wave structure are fixed at two axial top corners of the second grid, so that the crest of the wave structure passes through the second grid of the mesh located in the outer layer; the second edge bar includes multiple, and the multiple second edge bars are arranged axially.

[0021] Preferably, a plurality of elastic attachment components arranged in the axial direction and the circumferential direction are provided between each two adjacent layers of mesh, and the elastic attachment components are used to maintain the gap between the two adjacent layers of mesh.

[0022] Preferably, each layer of mesh comprises a plurality of mesh units arranged in the axial direction, with a reserved distance between adjacent mesh units, and a plurality of linear interconnected components allowing axial expansion and contraction between adjacent mesh units.

[0023] Preferably, the mesh is formed by laser engraving from a sheet member, and the surface member is formed by rolling after the meshes formed by engraving are attached by elastic attachment members.

[0024] Preferably, the base has a plurality of expansion petals, the plurality of expansion petals are circumferentially arranged and surround a central hole, and an expandable column is placed in the central hole;

[0025] The expandable column comprises a xenogeneic allogeneic dry bone and a wire mesh rolled around the dry bone. Hydrogel dry powder is filled between the wire meshes, and the wire mesh is made of bioabsorbable material.

[0026] Preferably, the cap portion comprises a plurality of stacked carrier sheets, each of which is made of a bioabsorbable material and has micropores configured thereon; wherein:

[0027] The slide is used for attaching hydrogel and chondrocytes.

[0028] Preferably, there is a transition portion between the base and the cap; wherein:

[0029] The core body is formed by stacking multiple layers of first support units in the axial direction, each layer of the first support units includes a plurality of first rods arranged radially, and the first rods of the first support units of adjacent layers are arranged crosswise to define the second pores;

[0030] The transition portion is formed by stacking multiple layers of second support units in the axial direction, wherein each layer of the first support units includes a plurality of radially arranged second rods, and the second rods of the second support units in adjacent layers intersect to define a third aperture;

[0031] The core body and the transition portion are integrally printed and formed by 3D printing technology.

[0032] Preferably, a shielding sheet is attached to the bottom of the cap.

[0033] Compared with the prior art, the cartilage repair component provided by the embodiments of the present invention has the following beneficial effects:

[0034] 1. The cartilage repair component provided by the present invention is coated with a surface portion on the base that achieves radial expansion by the power generated by cell proliferation and growth, thereby significantly improving the fusion effect of the junction area between the base and the underlying bone, and to a certain extent avoiding the occurrence of osteoporosis and bone edema.

[0035] 2. The cap portion of the cartilage repair component provided by the present invention can improve the growth environment of chondrocytes and prevent chondrocyte migration by attaching hydrogel on a slide made of bioabsorbable material. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In the drawings, which are not necessarily drawn to scale, the same reference numerals may describe similar components in different views. The same reference numerals with letter suffixes or different letter suffixes may represent different instances of similar components. The accompanying drawings generally illustrate various embodiments by way of example and not limitation, and together with the description and claims, serve to illustrate the embodiments of the invention. Where appropriate, the same reference numerals are used throughout the drawings to refer to the same or similar parts. Such embodiments are illustrative and are not intended to be exhaustive or exclusive of the embodiments of the present apparatus or method.

[0037] Figure 1 This is a schematic diagram of implanting the cartilage repair component provided by the present invention into the articular surface of the knee joint.

[0038] Figure 2 This is a view of the cartilage repair component provided by the present invention just after being implanted into bone tissue.

[0039] Figure 3 This is a diagram showing the state of the cartilage repair component provided by the present invention in bone tissue during the recovery period after surgery.

[0040] Figure 4 This is a schematic diagram of the three-dimensional structure of the cartilage repair component provided by the present invention.

[0041] Figure 5 This is a three-dimensional exploded view of the cartilage repair component provided by the present invention.

[0042] Figure 6 This is a cross-sectional view of the surface portion of the cartilage repair component provided by the present invention.

[0043] Figure 7 This is a front view of one of the surface meshes in the unfolded state.

[0044] Figure 8 It is a schematic diagram of the three-dimensional structure of the surface part in the unfolded state.

[0045] Figure 9 It is a side view of the surface portion in the unfolded state.

[0046] Figure 10 It is a schematic diagram of the connection structure between the inducing component and the elastic attachment component and the mesh in the unfolded state.

[0047] Figure 11 A cross-sectional view of an expandable column.

[0048] In the picture:

[0049] 100 - Repair component; 10 - Cap; 11 - Carrier; 12 - Shielding sheet; 20 - Base; 21 - Second aperture; 22 - First rod; 23 - Center hole; 24 - Core body; 30 - Transition portion; 31 - Third aperture; 32 - Second rod; 40 - Surface portion; 41 - First mesh; 42 - Second mesh; 43 - Third mesh; 441 - First grid; 442 - Second grid; 45 - First rib; 46 - Inducing member; 461 - Second rib; 47 - Linear interconnecting member; 48 - Elastic attachment member; 481 - Elastic leg; 49 - Mesh; 50 - Expandable column; 51 - Wire mesh; 52 - Dry bone; 200 - Knee joint; 201 - Cartilage; 202 - Transition region; 203 - Underlying bone; 204 - Bone hole. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] Unless otherwise defined, the technical or scientific terms used in the present invention shall have the usual meanings understood by persons of ordinary skill in the field to which the present invention belongs. The words "first", "second" and similar terms used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" mean that the elements or objects preceding the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0052] In order to keep the following description of the embodiments of the present invention clear and concise, detailed descriptions of known functions and known components are omitted.

[0053] The embodiment of the present invention discloses a cartilage repair component 100, which is used to repair damaged cartilage at the joint surface of a human limb, for example, Figure 1 As shown, the cartilage repair component 100 can be used to repair damaged cartilage at the articular surface of a knee joint 200. Figure 1The joint surface shown is merely exemplary, and the cartilage repair component 100 is not limited to repairing cartilage at the joint surface of the knee joint 200. The cartilage repair component 100 can also repair cartilage at joint surfaces such as the hip joint and the elbow joint.

[0054] When performing a cartilage repair surgery, after the damaged cartilage is removed, a bone hole 204 is drilled at the resection area corresponding to the damaged cartilage, and then the repair component 100 provided by the present invention is filled into the bone hole 204. This is basically the same as the surgical procedure performed by traditionally using bone plugs (or bone plugs) to repair cartilage. Therefore, the cartilage repair component 100 provided by the present invention does not result in additional surgical procedures.

[0055] like Figure 4 and Figure 5 Combined with Figure 2 and Figure 3 As shown, the repair component 100 includes: a cap portion 10, a transition portion 30 and a base 20; the base 20 includes a core body 24 and a surface portion 40 covering the outside of the core body 24, the cap portion 10, the transition portion 30 and the base 20 are stacked in sequence in the axial direction, and when performing a repair operation, the base 20 is inserted into the bone hole 204, and by pre-configuring the size of the repair component 100 and / or pre-configuring the size of the bone hole 204, after the base 20 is inserted into the bone hole 204, the base 20 corresponds to the lower bone 203 of the autologous bone tissue, the cap portion 10 corresponds to the cartilage 201 of the autologous bone tissue, and the transition portion 30 corresponds to the area between the lower bone 203 and the cartilage 201. During the recovery period after surgery, the chondrocytes in the cap 10 proliferate and grow to eventually form new cartilage to replace the damaged cartilage that has been removed. The transition portion 30 and the autologous underlying bone 203 corresponding to the base 20 proliferate and grow toward the transition portion 30 and the base 20 to enter the pores of the transition portion 30 and the base 20, thereby eventually fusing the transition portion 30 and the base 20 with the surrounding underlying bone 203, thereby achieving anchoring of the repair component 100.

[0056] Figure 4 The cap portion 10, transition portion 30, and base portion 20 are shown as cylindrical structures. However, this cylindrical structure is merely exemplary and does not limit the shapes of the cap portion 10, transition portion 30, and base portion 20 of the repair component 100 provided by the present invention. For example, cylindrical structures with elliptical cross-sections, plum petal cross-sections, or other shapes may also be used as the shapes of the cap portion 10, transition portion 30, and base portion 20. For example, when the base portion 20 is configured as a cylindrical structure with a plum petal cross-section, the bone hole 204 is also configured as a plum petal cross-section. As a result, the base portion 20 and the bone hole 204 cooperate to significantly restrict the torsion of the repair component 100.

[0057] The core body 24 of the base 20 and the surface part 40 covering the outside of the core body 24 are both configured as a porous structure, so that during the recovery period after surgery, the lower layer bone 203 grows radially inward under the guidance of the pores of the surface part 40 and the core body 24 and eventually fuses with the base 20; the transition part 30 is also configured as a porous structure, so that during the recovery period after surgery, under the guidance of the pores of the transition part 30, the bone cells in the transition area 202 between the cartilage 201 corresponding to the transition part 30 and the lower layer bone 203 grow radially inward and eventually fuse with the transition part 30.

[0058] The present invention provides a specific structure of the core body 24 of a porous structure, such as Figure 5 As shown, the core body 24 comprises multiple layers of first support units stacked axially. Each layer of first support units includes a plurality of first rods 22 spaced radially apart. The first rods 22 of adjacent layers are arranged at an angle and in a cross-section, thereby defining pores (hereinafter referred to as second pores 21) for guiding bone cell growth. The angles between the first rods 22 of adjacent layers can be 30°, 60°, 90°, etc. The cross-section of the first rods 22 can be rectangular, diamond-shaped, circular, etc.

[0059] The present invention provides a specific structure of the transition portion 30 of the porous structure, such as Figure 5 As shown, the structure of the transition portion 30 is similar to that of the core body 24. Specifically, the transition portion 30 includes multiple layers of second support units stacked in the axial direction. Each layer of second support units includes multiple second rods 32 spaced apart in the radial direction. The second rods 32 of adjacent layers are arranged at an angle and crosswise, thereby defining pores (which may be referred to as third pores 31) for guiding the growth of bone cells. The angles between the second rods 32 of adjacent layers can be 30°, 60°, 90°, etc. The cross-section of the second rod 32 can be rectangular, diamond-shaped, circular, etc. Figure 5 In the structure of the core body 24 and the transition portion 30 shown, the cross-section of the first rod 22 is rectangular, and the cross-section of the second rod 32 is circular.

[0060] In some preferred embodiments, the porosity of the transition portion 30 is configured to be lower than the porosity of the base 20, so that the hardness and stiffness of the transition portion 30 are greater than those of the base 20, so that the biomechanical properties of the transition portion 30 and its corresponding autologous region (transition region 202) and the biomechanical properties of the base 20 and its corresponding autologous region (underlying bone 203) are close.

[0061] In some preferred embodiments, the transition portion 30 and the base portion 20 are integrally formed from the same material through 3D printing. Compared with the method of forming the parts separately and then attaching them, the integral 3D printing method makes the combination of the transition portion 30 and the base portion 20 better.

[0062] The materials used to make the transition portion 30 and the base 20 include biocompatible materials and bioabsorbable (degradable) materials. The biocompatible materials include metal materials, inorganic materials, and polymer materials. The biocompatible materials specifically include but are not limited to: titanium, magnesium, hydroxyapatite, polyurethane, amide lipids, etc. The bioabsorbable (degradable) materials specifically include but are not limited to: polycaprolactone, polyglycolic acid, polylactic acid, collagen, etc.

[0063] Before filling the repair component 100 into the bone hole 204, that is, before performing the cartilage repair surgery, growth factors that induce osteoblast proliferation and growth are attached to the core body 24, the transition part 30 and the surface part 40. For example, metal oxides or inorganic substances such as calcium oxide, zirconium oxide, and hydroxyapatite are coated on the surface of the pore structure. For another example, high molecular protein substances such as recombinant human BMP are filled in the pores.

[0064] In some embodiments, the core body 24 and the transition portion 30 are made of xenogeneic dry bone 52 or allogeneic dry bone 52. Preferably, the dry bone 52 is obtained from bone tissue of a xenogeneic / homogeneic bone joint. Thus, the obtained dry bone 52 comprises both a dried underlying bone 203 layer and a transition region layer. Furthermore, after the obtained bone tissue is formed into the dry bone 52, the dry bone 52 is drilled to create pores that guide bone cell growth.

[0065] A key technology of the present invention is the addition of a surface portion 40 covering the outside of the core body 24. The function and advantage of the surface portion 40 are: during the recovery period after surgery, the surface portion 40 can significantly promote the radial proliferation and growth of osteoblasts from the underlying bone 203, and ultimately achieve a better fusion result between the base 20 and the underlying bone 203, and prevent bone edema and osteoporosis from occurring in the junction area between the base 20 and the underlying bone 203, which is beneficial to improving the anchoring of the autologous bone tissue to the repair component 100, and is beneficial to maintaining the stability of the new cartilage of the cap 10 and the surrounding autologous cartilage 201, avoiding the collapse of the joint surface due to the loosening of the underlying bone 203.

[0066] The surface layer portion 40 can achieve the above-mentioned effect because: during the recovery period after surgery, Figure 3As shown, the surface portion 40 continuously and slowly stimulates the underlying bone 203 by continuously and slowly expanding radially, thereby promoting osteoblast proliferation and growth. Furthermore, the expansion of the surface portion 40 is derived from the force exerted on the surface portion 40 by the cell proliferation and growth, that is, from the power generated by the cell proliferation and growth. Therefore, the cell proliferation and growth and the expansion of the surface portion 40 proceed synchronously and mutually promote each other, thereby increasing the density of the bone tissue (cells) at the junction between the underlying bone 203 and the base portion 20. Because the power for the radial expansion of the surface portion 40 comes from the proliferation and growth of osteoblasts rather than from elastic repositioning, it is not necessary to insert the base portion 20 into the bone hole 204 with a large preload during the procedure. That is, after the base portion 20 is inserted into the bone hole 204, a gap is allowed between the surface portion 40 and the bone hole 204, thereby reducing the difficulty of performing the procedure and the difficulty of pre-operatively configuring the dimensions of the bone hole 204 and the base portion 20.

[0067] like Figure 6 and Figure 7 , and combined with Figure 4 and Figure 5 As shown, the surface portion 40 specifically includes multiple layers of tubular mesh that are nested with each other. The accompanying drawings show a structure of the surface portion 40 composed of three layers of mesh. The three layers of mesh may be referred to as the first mesh 41, the second mesh 42, and the third mesh 43 from the outer layer to the inner layer. The grids in each layer of mesh serve as pores in the surface portion 40 for guiding the proliferation and growth of osteoblasts (the pores may be referred to as first pores). The grid of the mesh is formed by the cross-connection of the first ribs 45, and the grid formed by the first ribs 45 is a rhombus. The rhombus-shaped grid has the following characteristics: two of the opposite vertices of the grid are opposite in the axial direction of the base 20, and the other two opposite vertices of the grid are opposite in the axial direction of the base 20. 0, and the angle of the two vertex angles that are opposite in the axial direction is smaller than the angle of the two vertex angles that are opposite in the circumferential direction, that is, the angle of the two vertex angles that are opposite in the axial direction is smaller than 90° (for example, the vertex angle is 60°), and the angle of the two vertex angles that are opposite in the circumferential direction is greater than 90° (for example, the vertex angle is 120°). The mesh formed by the grid of the above structure can produce radial expansion, and by making the two vertex angles in the axial direction smaller than the two vertex angles in the circumferential direction, the mesh is allowed to undergo a greater degree of radial expansion.

[0068] When performing cartilage surgery, e.g. Figure 2As shown, after the base 20 is inserted into the bone hole 204, the layers of mesh of the surface portion 40 of the base 20 are in a natural unexpanded state; in the early recovery period after the operation, the osteoblasts of the lower bone 203 near the hole wall of the bone hole 204 proliferate and grow toward the surface portion 40, and enter the surface portion 40 through the grid (i.e., the first pore) of the mesh of the surface portion 40. Subsequently, the osteoblasts proliferate and grow in the surface portion 40. Since the porosity and pore size of the second pores 21 of the core body 24 of the base 20 are smaller than the porosity and pore size of the first pores of the surface portion 40, the osteoblasts preferentially proliferate and grow in the surface portion 40. The volume increase caused by the proliferation and growth of osteoblasts will cause circumferential and radial forces to be applied to the mesh of the surface portion 40, as shown in FIG. Figure 3 As shown, this causes the mesh to expand radially, and this expansion causes the first ribs 45 that form the grid to move radially toward the underlying bone 203, stimulating the underlying bone layer and promoting the continued proliferation of osteoblasts in the underlying bone 203. This increases the bone density of the annular region between the core body 24 and the underlying bone 203, thereby improving the fusion effect between the base 20 and the underlying bone 203 and, to a certain extent, preventing the occurrence of osteoporosis in the junction area between the base 20 and the underlying bone 203. Furthermore, since the base 20 does not need to be inserted into the bone hole 204 with a large preload during surgery, impact and compression damage to the bone tissue of the hole 204 wall is avoided. Therefore, bone edema is prevented to a certain extent during the recovery period. Furthermore, during the recovery period, the expansion of the surface portion 40 prevents the formation of gaps in the junction area, thus also preventing the occurrence of bone edema during the recovery period.

[0069] In addition, the power of the mesh expansion comes from the proliferation and growth of osteoblasts. Therefore, the expansion process of the surface part 40 is synchronized with the proliferation and growth of osteoblasts. Therefore, after the osteoblasts complete proliferation and growth, that is, after recovery, the mesh will no longer continue to expand.

[0070] In some preferred embodiments, the expansion stiffness of the mesh decreases successively from the inner layer to the outer layer, that is, the expansion stiffness of the first mesh 41 is smaller than the expansion stiffness of the second mesh 42, and the expansion stiffness of the second mesh 42 is smaller than the expansion stiffness of the third mesh 43.

[0071] It should be noted that in the present invention, expansion stiffness is used to measure the ability of the mesh to resist expansion deformation. The smaller the expansion stiffness, the worse the ability to resist expansion deformation, the easier it is to expand and deform, and vice versa, the less likely it is to expand and deform. Correspondingly, the mesh with diamond grids can also undergo shrinkage deformation. Therefore, the mesh also has shrinkage stiffness, and the size of the shrinkage stiffness is consistent with the expansion stiffness, that is, the greater the expansion stiffness of the mesh, the greater the shrinkage stiffness of the mesh.

[0072] The advantage of configuring the expansion stiffness of different layers of mesh to change in a gradient is that the osteoblasts located in the surface part 40 preferentially force the outer layer of mesh to expand through proliferation and growth, and the expansion amplitude of the outer layer of mesh is greater than the expansion amplitude of the inner layer of mesh, which makes the density and mechanical properties of bone tissue form a transition from the lower bone 203 to the base 20.

[0073] like Figures 6 to 8 As shown, the present invention provides a method for making the expansion stiffness of the inner mesh greater than the expansion stiffness of the outer mesh. That is, the width of the first ridge bar 45 of the mesh forming the outer mesh is made smaller than the width of the first ridge bar 45 of the mesh forming the inner mesh. The so-called width of the first ridge bar 45 refers to the circumferential dimension of the first ridge bar 45. In other words, the width of the first ridge bar 45 of the first mesh 41 is made smaller than the width of the first ridge bar 45 of the second mesh 42, and the width of the first ridge bar 45 of the second mesh 42 is made smaller than the width of the first ridge bar 45 of the third mesh 43.

[0074] In some preferred embodiments, Figures 6 to 10 As shown, an induction component 46 is added to the surface portion 40 to further promote the proliferation and growth of bone cells. Specifically, the grid includes first grids 441 and second grids 442 arranged circumferentially in alternating rows. The first grids 441 on each layer of the mesh face each other, and the second grids 442 on each layer of the mesh face each other. From the outer layer to the inner layer, the area enclosed by the first grids 441 of the mesh decreases, while the area enclosed by the second grids 442 of the mesh increases. The induction component 46 includes a plurality of second ridges 461 that are bent to form a wavy structure. Except for the outermost layer, each layer of the mesh is attached with a large number of second edge rods 461, that is, the second mesh 42 and the third mesh 43 are both attached with the second edge rods 461. The specific arrangement of the second edge rods 461 is as follows: the second edge rods 461 are axially arranged in the column where the second grid 442 of the mesh is located, and each two adjacent troughs of the wave structure are fixed at the two axial top corners of the second grid 442, so that the crest of the wave structure passes through the second grid 442 of the mesh located in the outer layer, that is, the crest of the wave structure of the second edge rod 461 attached to the third mesh 43 passes through the second grid 442 of the second mesh 42 and protrudes outside the second mesh 42, and the crest of the wave structure of the second edge rod 461 attached to the second mesh 42 passes through the second grid 442 of the first mesh 41 and protrudes outside the first mesh 41. In addition, a plurality of second ribs 461 are circumferentially arranged on each layer of mesh, and the second ribs 461 on the inner layer of mesh are circumferentially staggered with the second ribs 461 on the outer layer of mesh to avoid interference between the second ribs 461 on two adjacent layers of mesh.

[0075] The advantage of adding the induction component 46 to the surface layer 40 is that when osteoblasts proliferate and grow, causing the inner mesh to expand, the crests of the second ridges 461 further penetrate into the underlying bone 203 or osteoblasts, thereby stimulating them to continue proliferating, thereby further enhancing the fusion effect of the junction area. The reason for not attaching the second ridges 461 to the outermost mesh layer is that it would be difficult to insert the base 20 into the bone hole 204 during surgery, and it is undesirable to overstimulate the underlying bone 203 with the induction component 46 during the initial recovery period after surgery.

[0076] In addition, when the mesh expands, the two vertices of the diamond-shaped grid in the axial direction approach each other, so that the crest of the second ridge rod 461 is further protruded, which is beneficial to stimulate the underlying bone 203.

[0077] The materials for making the mesh of the surface portion 40 include: biocompatible materials and bioabsorbable (degradable) materials. The compatible materials include metal materials, inorganic materials, and polymer materials. The biocompatible materials specifically include but are not limited to: titanium, magnesium, polyurethane, amide lipids, etc. The bioabsorbable (degradable) materials include but are not limited to: polycaprolactone, polyglycolic acid, polylactic acid, etc.

[0078] Preferably, a material suitable for laser engraving is selected as the material for making the mesh, and specifically, an alloy material is preferably used to make the mesh, for example, titanium alloy is selected.

[0079] The mesh sheet composed of the grid is preferably formed by laser engraving, specifically, Figure 7 As shown, a mesh with a grid structure is engraved on a flattened sheet using a laser engraving machine, so that the width of the first edge rods 45 of the inner mesh is greater than the width of the first edge rods 45 of the outer mesh.

[0080] The surface layer 40 is made by using the mesh formed by carving as follows: Figures 8 to 10As shown, a plurality of second edge rods 461 and a plurality of elastic attachment parts 48 are attached to each mesh except the outermost layer by laser welding, and then the meshes are stacked in sequence. Before each layer of mesh is stacked, solder is uniformly coated on the outer end faces of the plurality of elastic attachment parts 48, and then the meshes are stacked, and then the meshes are heated so that the elastic attachment parts 48 and the stacked meshes are fixedly connected by welding, and then a cylindrical surface portion 40 is obtained by bending the stacked meshes, and then the surface portion 40 is wrapped around the core part, and then the two side edges of the mesh are attached by welding to seal it. The present invention also provides a method for preventing the surface portion 40 from separating from the core body 24: when using a 3D printer to print the core body 24, through a preset printing program, when printing the first rod body 22 in layers, the ends of part of the first rod body 22 extend outside the cylindrical surface enclosed by the core body 24. Therefore, after the surface portion 40 is wrapped around the outside of the core body 24, the ends of part of the first rod body 22 radially extend into the surface portion 40 through the grid of the mesh, thereby limiting the torsion and axial movement of the surface portion 40 relative to the core body 24.

[0081] In some preferred embodiments, Figure 6 and Figure 8 As shown, the elastic attachment component 48 includes four bent elastic legs 481 and attachment pieces located on both sides of the four elastic legs 481. The attachment pieces are configured into a diamond shape that matches the grid structure of the mesh. The four elastic legs 481 are connected to the four top corners of the attachment piece. The attachment pieces on both sides of the elastic legs 481 are attached (e.g., welded) to the first edge rods 45 of the two adjacent layers of mesh that form the first grid 441.

[0082] In some preferred embodiments, Figure 4 and Figure 8 As shown, each layer of mesh includes multiple mesh units arranged in the axial direction, with a reserved distance between adjacent mesh units. Furthermore, multiple linear interconnecting components 47 are provided between adjacent mesh units to allow for axial expansion and contraction. These linear interconnecting components 47 can be formed by reciprocating bending of rod-shaped components. Thus, when the mesh expands, the linear interconnecting components 47 extend to compensate for the axial contraction of the mesh units due to expansion, thereby preventing the surface portion 40 from being axially shortened as a whole due to expansion. The accompanying drawings of the present invention only illustrate the linear interconnecting components 47 on the first mesh 41; in reality, the second mesh 42 and the third mesh 43 also have linear interconnecting components 47.

[0083] Another key technology of the present invention is: Figure 2 and Figure 3As shown, during the initial postoperative recovery period, base 20 expands slightly to contact the wall of bone hole 204, eliminating the gap between base 20 and bone hole 204. This not only facilitates the growth of underlying bone 203 toward base 20 but also prevents bone edema to a certain extent. The method employed by the present invention is to form multiple expansion flaps separated by gaps in the middle and lower portion of base 20. These expansion flaps are arranged circumferentially and define a central hole 23, into which an expandable column 50 is placed.

[0084] like Figure 11 As shown, the expandable column 50 includes a dry bone 52, a wire mesh 51, and hydrogel powder. The dry bone 52 is made from the same or different bone through drying, and holes are drilled in the dry bone 52. The wire mesh 51 can be made of a bioabsorbable material, such as polycaprolactone or recombinant human BMP protein. Specifically, for example, the wire mesh 51 is made by weaving polycaprolactone and recombinant human BMP protein into silk threads. A plurality of wire meshes 51 are arranged circumferentially along the dry bone 52, with the inner ends bonded to the dry bone 52. The plurality of wire meshes 51 are rolled around the dry bone 52, and the spaces between the wire meshes 51 are filled with hydrogel powder. During the initial recovery period after the surgery, the hydrogel powder on the expandable column 50 absorbs water, forcing the expansion flap to slightly expand, thereby eliminating the gap between the base 20 and the bone hole 204. After the osteoblasts proliferate and grow to the expandable column, the hydrogel facilitates the proliferation and growth of the osteoblasts, and the wire mesh 51 is gradually absorbed, thereby allowing the internal dry bone 52 to fuse with the base 20 .

[0085] The above-mentioned expansion flaps belonging to the core body 24 are made in the following manner: when printing the core body 24, a gap is printed on the core body 24 through a preset printing program.

[0086] The portion of the expansion flap belonging to the surface portion 40 is made in the following manner: when carving the mesh, a preset carving program is used to carve gaps on the mesh.

[0087] Another key technology of the present invention is: Figure 4 and Figure 5As shown, a cap 10 is configured that can effectively prevent chondrocyte migration and is suitable for chondrocyte proliferation and growth. The cap 10 includes a plurality of stacked slides 11, and numerous micropores are formed on the slides 11. The slides 11 are printed or woven from bioabsorbable materials such as polycaprolactone and recombinant human BMP protein. When making the cap 10, an appropriate amount of hydrogel dry powder and cartilage stem cells are attached to the slide 11. Then, the cap 10 is placed in a culture dish to allow the chondrocytes to proliferate. During this process, the hydrogel absorbs water and swells. After the operation is performed, the hydrogel provides a better proliferation and growth environment for the chondrocytes. After the chondrocytes complete proliferation and growth, the slide 11 is gradually degraded and / or absorbed. In addition, after the operation is performed, the hydrogel has an adsorption effect, thereby limiting the migration of chondrocytes.

[0088] In some preferred embodiments, a shielding sheet 12 is attached to the bottom of the cap 10. The shielding sheet 12 is also formed by printing and weaving a bioabsorbable material such as polycaprolactone or recombinant human BMP protein. Unlike the carrier sheet 11, the aperture of the micropores of the shielding sheet 12 is significantly smaller than the aperture of the micropores of the carrier sheet 11, so as to limit the growth of chondrocytes toward the transition portion 30 and the base 20.

[0089] The above embodiments are merely exemplary embodiments of the present invention and are not intended to limit the scope of the present invention. The scope of protection of the present invention is defined by the claims. Those skilled in the art may make various modifications or equivalent substitutions to the present invention within the spirit and scope of protection of the present invention, and such modifications or equivalent substitutions shall also be deemed to fall within the scope of protection of the present invention.

Claims

1. A cartilage repair component, comprising: The invention relates to a base portion for inserting into a bone hole in a resection area of ​​a joint surface where damaged cartilage has been removed for fusing with the underlying bone, and a cap portion for filling the resection area after the base portion is inserted into the bone hole and for receiving chondrocytes; characterized in that: The base includes a columnar core body and a surface layer covering the core body; the surface layer and the core body are respectively configured with a plurality of first pores and a plurality of second pores for guiding the radial growth of osteoblasts; The surface portion includes multiple layers of tubular mesh that are nested with each other, with meshes in each layer of the mesh serving as first pores. The meshes of the mesh are configured in a rhombus shape, and two of the opposing vertices of the mesh are located in the axial direction, while the other two opposing vertices are located in the circumferential direction. The angles of the two axial vertices are smaller than the angles of the two circumferential vertices, so that the mesh can expand radially. As a result, after osteoblasts of the underlying bone grow toward the base and enter the first pores of the surface portion, the osteoblasts proliferate and grow in the surface portion, causing the mesh to expand and radially invade the underlying bone. The expansion stiffness of each layer of mesh in the surface layer is configured such that the expansion stiffness of the outer layer mesh is smaller than the expansion stiffness of the inner layer mesh; The mesh is formed by cross-connected first ribs, and the expansion stiffness of the outer mesh is smaller than that of the inner mesh by making the width of the first ribs of the mesh forming the outer mesh smaller than the width of the first ribs of the mesh forming the inner mesh; The grid includes first grids and second grids that are alternately arranged circumferentially in a column manner; the first grids on each layer of the grid are opposite to each other, and the second grids on each layer of the grid are opposite to each other; wherein: From the outer layer to the inner layer, the area enclosed by the first grid of the mesh decreases, and the area enclosed by the second grid of the mesh increases; A radially protruding induction component is fixed on the first edge rod of the mesh located in the inner layer, and the induction component radially passes through the second grid of the mesh located in the outer layer.

2. The cartilage repair component according to claim 1, characterized in that The inducing component includes a second rib, which is bent to form a wave structure. The second rib is axially arranged in the column of the second grid of the mesh. Each two adjacent troughs of the wave structure are fixed at two axial top corners of the second grid, so that the crest of the wave structure passes through the second grid of the mesh located in the outer layer; the second rib includes a plurality of second ribs, and the plurality of second ribs are arranged circumferentially at intervals.

3. The cartilage repair component according to claim 1, characterized in that A plurality of elastic attachment components arranged along the axial direction and the circumferential direction are provided between every two adjacent layers of mesh sheets, and the elastic attachment components are used to maintain the gap between the two adjacent layers of mesh sheets.

4. The cartilage repair component according to claim 1, characterized in that Each layer of mesh includes a plurality of mesh units arranged in the axial direction, a reserved distance is provided between adjacent mesh units, and a plurality of linear interconnected components allowing axial expansion and contraction are provided between adjacent mesh units.

5. The cartilage repair component according to claim 3, characterized in that: The mesh is formed by laser engraving from a sheet member, and the surface layer portions of the meshes formed by engraving are attached by elastic attachment members and then rolled.

6. The cartilage repair component according to claim 1, characterized in that The base has a plurality of expansion petals, which are arranged circumferentially and surround a central hole, and an expandable column is placed in the central hole; The expandable column comprises a xenogeneic allogeneic dry bone and a wire mesh rolled around the dry bone. Hydrogel dry powder is filled between the wire meshes, and the wire mesh is made of bioabsorbable material.

7. The cartilage repair component according to claim 1, characterized in that: The cap portion includes a plurality of stacked slides, each of which is made of a bioabsorbable material and has micropores configured thereon; wherein: The slide is used for attaching hydrogel and chondrocytes.

8. The cartilage repair component according to claim 1, characterized in that: There is a transition portion between the base and the cap; wherein: The core body is formed by stacking multiple layers of first support units in the axial direction, each layer of the first support units includes a plurality of first rods arranged radially, and the first rods of the first support units of adjacent layers are arranged crosswise to define the second pores; The transition portion is formed by stacking multiple layers of second support units in the axial direction, each layer of the second support units includes a plurality of second rods arranged radially, and the second rods of the second support units in adjacent layers intersect to define a third aperture; The core body and the transition portion are integrally printed and formed by 3D printing technology.

9. The cartilage repair component according to claim 1, characterized in that: A shielding sheet is attached to the bottom of the cap.

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