CN114176845A

CN114176845A - Bionic bone graft for filling individual customized long bone defect

Info

Publication number: CN114176845A
Application number: CN202210003609.9A
Authority: CN
Inventors: 李泳龙; 程晓东; 姚孟轩; 陈伟
Original assignee: Third Hospital of Hebei Medical University
Current assignee: Third Hospital of Hebei Medical University
Priority date: 2022-01-05
Filing date: 2022-01-05
Publication date: 2022-03-15

Abstract

The invention discloses a bionic bone graft block for filling individual customized long bone defects, which has biocompatibility and is a topology optimization structure and comprises a support cylinder, a middle filling body and an inner filling body from outside to inside. The support cylinder is of a compact cylindrical structure, connecting parts which are connected with cortical bone in a socket mode are arranged at two ends of the support cylinder, fusion parts are further arranged at two ends of the inner wall of the support cylinder, the fusion parts are annular and made of degradable materials with porous lattice structures, and the outer side end faces of the fusion parts are in contact with the end faces connected with cortical bone; the middle filling body is arranged in the supporting cylinder and filled between the two fusion parts and is made of degradable materials, the inner filling body is filled in the middle filling body, two ends of the inner filling body do not extend into the fusion parts, and the middle filling body and the inner filling body are formed by stacking a plurality of porous unit cell units. The compact non-degradable material and the loose porous degradable material are combined, the mechanical property of the composite material is optimized through a topological structure, and meanwhile, the growth bionics of the composite material is realized by utilizing different lattice morphological characteristics, so that the rapid osteogenesis is promoted.

Description

Bionic bone graft for filling individual customized long bone defect

Technical Field

The invention relates to the technical field of medical instruments, in particular to a bionic bone graft block for filling individual customized long bone defects.

Background

In clinic, long bone diaphysis multiple fracture is a kind of operation with high tearing reduction difficulty, and the common scheme is that only simple functional reduction can be performed. The reduced limb has poor load bearing capacity.

With the rapid development of biological materials and digital medical technology in recent years, the bionic prosthesis with a porous structure is developed rapidly, and brings hope for the rehabilitation of many patients, the existing long bone backbone prosthesis is usually in a customized mode, a healthy side bone model of a patient is mirrored to the affected side according to CT data of long bones on two sides of the patient, the shape of the affected side before disease is restored one by one through commands of registration, cutting, construction and the like, and finally the final affected part replacement prosthesis is formed through porous editing.

In the prior art, various bone filling prostheses are generally formed by homogeneous porous structures, and the whole body material is single, and can be roughly classified into metal magnesium titanium alloy or degradable material such as levorotatory polylactic acid (PLLA) or caprolactam Monomer (MC). Because the homogeneous porous structure of the metal prosthesis is in linear contact with the bone contact surface, like a bone filling block disclosed in the patent ZL202021832757.4 of Chinese utility model, the joint part has strong specific pressure, which leads to the settlement of the bone surface, the non-healing of the prosthesis and the bone, and finally the failure of the operation. Although the degradable material has high bonding degree with the bone, the prior art has poor structural performance, cannot bear large stress, cannot meet the requirements of strength, rigidity, elastic modulus and the like of a bone defect part, and influences the bone growth and the long-term osseointegration of an implant in a human body.

Therefore, a prosthesis with good mechanical properties and strong bone tuberculation is needed.

Disclosure of Invention

The invention aims to solve the technical problem of providing a bionic bone graft for filling the defect of the body-customized long bone, which not only utilizes the combination of compact non-degradable materials and loose porous degradable materials, optimizes the mechanical property through a topological structure, but also utilizes different lattice morphological characteristics to realize the growth bionics and promotes the rapid bone formation.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows:

individual customization formula long bone defect fills uses bionical transplantation bone piece, has biocompatibility, its characterized in that, is the columnar structure of multilayer, includes from outside to inside:

the support cylinder is of a compact cylindrical structure, connecting parts which are connected with cortical bone in a socket mode are arranged at two ends of the support cylinder, fusion parts are further arranged at two ends of the inner wall of the support cylinder, the fusion parts are annular and made of degradable materials with porous lattice structures, and the outer side end faces of the fusion parts are in contact with the end faces connected with cortical bone;

the middle filling body is arranged in the supporting cylinder and filled between the two fusion parts, and the middle filling body is made of degradable materials; and

an inner filling body filled in the inner filling body, wherein two ends of the inner filling body do not extend into the fusion part;

the middle filling body and the inner filling body are both of topology optimization structures and are formed by stacking a plurality of porous unit cell units, and each porous unit cell unit is of a hollow three-dimensional structure formed by a plurality of compact rods;

compared with the porous unit cell in the inner filling body, the porous unit cell of the middle filling body has larger volume and thicker rod.

The further technical proposal is that the end surface of the fusion part contacting with the cortical bone is a particle surface.

A further technical solution is that each porous cell unit is a hexahedron composed of two triangular pyramids, each hexahedron is composed of six compact rods, and a plurality of porous cell units are stacked on top.

The technical scheme is that the bionic bone graft block is integrally formed by 3D printing.

The technical scheme is that the length of the connecting part is 5-300 mm.

The technical scheme is that the fusion part is of a topological optimization structure and is provided with an inner ring wall and an outer ring wall, a plurality of partition plates which are axially arranged at intervals are arranged between the inner ring wall and the outer ring wall, and protruding columns are arranged on two end faces of each partition plate.

The further technical proposal is that the baffle plate on the outermost side of the connecting part of the near end is lower than the inner ring wall and the outer ring wall, and a reservoir is formed by the baffle plate, the inner ring wall and the outer ring wall.

A further technical proposal is that the inner ring wall of the connecting part at the proximal end is provided with a notch.

The technical scheme is that a through notch is formed in the side wall of the middle filling body.

The further technical scheme is that the pores on the fusion part are smaller than the pores on the middle filling body.

Adopt the produced beneficial effect of above-mentioned technical scheme to lie in:

the compact non-degradable material and the loose porous degradable material are combined, the mechanical property of the composite material is optimized through a topological structure, and meanwhile, the growth bionics of the composite material is realized by utilizing different lattice morphological characteristics, so that the rapid osteogenesis is promoted.

The support section of thick bamboo is closely knit non-degradation material, has the same intensity, for the bone piece provides whole support, increases holistic structural strength, and the both ends of a support section of thick bamboo link to each other through the mode of socket joint with the long bone near-end that meets and long bone distal end, realize the stable contact of prosthesis and skeleton, guarantee the stability of bone piece implantation back position.

Further, still have the degradable of round and fuse the portion at the both ends of the inner arm of a support section of thick bamboo, for the porous lattice structure that the imitative skin fuses the growth, fuse the portion and carry out the face for the long bone that meets and support, increase the area of contact of skeleton section and false body, guarantee that the atress is even still can promote osteoblast and nutrient substance's area of contact outward to can guarantee the stronger activity of cell, make the false body combine more durable with the growth of skeleton, increase the combination degree of broken end.

The support cylinder is filled with filling bodies of different materials and densities.

The interior packing body is located the central point of bone piece, the lattice form of vertical growth, and its lattice structure bears the form design according to the vertical of bone trabecula, and every lattice constitutes for the mode that the space triangular pyramid top was piled up, can disperse each part of structure with stress concentration area, greatly increased overall structure's stability, big hole has under the condition of guaranteeing mechanical properties, the outside biological material of being convenient for adheres to, and the structure is penetrating, does not influence the blood supply in the skeleton.

The middle layer filling body is positioned in an annular cavity surrounded by the inner filling body, the supporting cylinder and the fusion part, the middle layer is filled into a loose structure with certain space stability, a larger space is provided for the space residence of osteoblasts, and meanwhile, the contact area between the osteoblasts and nutrient substances can be greatly improved by the porous lattice structure, so that the stronger activity of the cells can be ensured, and the prosthesis is more firm in combination with the growth of bones.

And the two ends of the inner filling body do not extend into the fusion part, namely after the inner filling body is implanted initially, the inner filling body does not directly contact with the bone, the bone collapse is not caused by point contact, but the inner filling body is integrated with the bone after blood flows in and osteoblasts form bone, and the mechanical strength of the limb is improved.

Drawings

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

FIG. 1 is an illustration of a biomimetic bone graft of the present disclosure in combination with a long bone;

FIG. 2 is a schematic structural view of a biomimetic bone graft of the present disclosure;

FIG. 3 is a schematic cross-sectional view of a biomimetic bone graft of the present disclosure;

FIG. 4 is a schematic structural view of a filling body in a biomimetic bone graft according to the present disclosure;

fig. 5 is a schematic structural view of the bionic bone graft intra-block filler of the present disclosure.

Detailed Description

The technical solutions in the embodiments of the present invention are clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways than those specifically described and will be readily apparent to those of ordinary skill in the art without departing from the spirit of the present invention, and therefore the present invention is not limited to the specific embodiments disclosed below.

As shown in fig. 1 to 5, the individual customized bionic bone graft for filling a long bone defect has biocompatibility and is a biological embedding substance which does not cause the attack of the immune system of the organism. The bionic bone graft is of a multi-layer columnar structure and comprises a supporting cylinder 1, an inner filling body 2 and an inner filling body 3 from outside to inside. The whole bionic bone graft is integrally formed by adopting an ink-jet 3D printing technology (3 DP).

The supporting cylinder 1 is a compact cylindrical structure, cannot be absorbed and degraded, and can be made of metal materials such as pure titanium, stainless steel, cobalt-based alloy, titanium-based alloy, magnesium-titanium alloy and the like, or non-degradable high polymer materials such as PA plastic, Polyethylene (PE) and the like.

The two ends of the supporting cylinder 1 are provided with connecting parts 101 which are inserted and connected with cortical bone, and the connecting parts 101 can be bellmouths which contain the cortical bone or sockets which are inserted into the cortical bone. Connecting portion 101 mainly is the boss of cooperation skeleton outer wall cutting area, makes its cooperation that can be more stable, effectively avoids the bone piece to deviate from, and connecting portion 101's length is 5 ~ 300mm, guarantees the stability of connecting. Support section of thick bamboo 1 is closely knit non-degradation material, has the same intensity, for the bone piece provides whole support, increases holistic structural strength, and the both ends of a support section of thick bamboo 1 link to each other through the mode of socket joint with the long bone near-end and the long bone distal end that meet, realize the stable contact of prosthesis and skeleton, guarantee the stability of bone piece implantation back position.

The support tube 1 further has fusion parts 102 at both ends of the inner wall, the fusion parts 102 are annular and made of degradable material with porous lattice structure, and the outer end surface of the fusion part 102 is in contact with the end surface of cortical bone. The fusion part 102 is a topology optimization structure, and has an inner annular wall and an outer annular wall, a plurality of axially spaced partition plates are arranged between the inner annular wall and the outer annular wall, protruding columns are arranged on two end faces of each partition plate, and the end face of the fusion part 102, which is in contact with the cortical bone of the bone, is a particle surface. A small groove is formed between the convex column and the partition plate, blood can enter the groove, osteoblasts are carried in the blood, and a bone and bone-like trabecular structure can be formed in the place where the blood flows sufficiently, so that the holding force between the bone and the implant can be increased.

Furthermore, the outermost partition on the proximal connecting portion 101 is lower than the inner and outer annular walls, which form a reservoir for storing blood, and the blood-filled region is finally the osteogenic region. The inner annular wall of the proximal connecting portion 101 has a notch for facilitating blood circulation.

The fusion part 102 is a porous lattice structure grown by the imitation cortex fusion, the fusion part 102 is used for supporting the connected long bones, the contact area of the bone fracture surface and the prosthesis is increased, the stress is ensured to be uniform, and the contact area of osteoblasts and nutrients can be increased, so that the stronger activity of the cells can be ensured, the prosthesis is more firm in combination with the growth of the bones, and the combination degree of the fracture ends is increased.

The support cylinder 1 is filled with fillers of different materials and densities. The middle filling body 2 is arranged in the support cylinder 1 and filled between the two fusion parts 102, and the middle filling body 2 is made of degradable materials. The inner filler 3 is filled in the inner filler 2, and both ends thereof do not extend into the fusion portion 102 and are not degraded by absorption. The fusion part 102 and the middle filling body 2 may be made of the same material, and the absorption rate is not sequential, and usually two weeks is enough for the osteogenesis to start healing.

The middle filling body 2 and the inner filling body 3 are both topology optimization structures and are formed by stacking a plurality of porous unit cell units, and each porous unit cell unit is of a hollow three-dimensional structure formed by a plurality of compact rods. Preferably, each of the porous unit cells is a hexahedron composed of two triangular pyramids, each hexahedron is composed of six compact rods, and a plurality of porous unit cells are stacked on top of each other. The porous cell units of the middle packing 2 are larger in volume and thicker in composition than the porous cell units of the inner packing 3 in the inner packing 3.

The fusion part 102 and the middle filling body 2 are made of degradable materials, the materials can be the same, the absorption rates are not sequential, and the bone formation starts to heal after two weeks. The fusion part 102 and the middle filling body 2 adopt different lattice forms because the place where the blood flows is osteogenic in consideration of the direction of the blood flow and the direction of the formation of the trabecular bone, so that the different structures are made because the blood can be more closely combined with the bone after the blood is osteogenic, and because the bone is not autologous bone, the degree of freedom must be better limited by various spatial structures.

The holes of the fusion part 102, the filler 2 and the filler 3 in the bionic bone graft are sequentially increased. The small vertical gap in the fusion 102 may promote osteoblast differentiation into a relatively firm cortex after blood flow therethrough. The middle filling body 2 is a fusion part for the purpose of forming a cancellous bone trabecular structure, and the most desirable molding size of the structure is a pore diameter of 300um-1mm, so that the lattice of the structure is most suitable with the size. The inner filling body 3 is a supporting structure, needs a large triangular frame for mechanical structural support, needs certain elasticity, and can be slightly deformed to disperse stress concentration when being pressed, a bone stem area of a long bone of the bone is hollow, bone marrow is arranged inside the hollow long bone, and the large size is to avoid influencing the normal function of the bone marrow, and the bone marrow can be changed into red bone marrow hematopoiesis again after operation to promote osteogenesis, so the structure needing large filling is needed.

Furthermore, the side wall of the middle filling body 2 is provided with a through gap which is a nourishing hole of a bionic bone and is convenient for differentiation and molding of blood supply. Ensuring the activity of the osseointegration formed in the implant at the later stage.

Pack the central part that the body 3 is located the bone piece, the lattice form of vertical growth, its lattice structure bears the weight of the morphological design according to the vertical of bone trabecula, every lattice constitutes for the mode that the space triangular pyramid top was piled up, can disperse each part of structure with stress concentration area, greatly increased overall structure's stability, big hole has under the condition of guaranteeing mechanical properties, the outside biological material of being convenient for adheres to, and the structure is penetrating, does not influence the blood supply in the skeleton.

The middle layer filling body is positioned in an annular cavity surrounded by the inner filling body 3, the supporting cylinder 1 and the fusion part 102, the middle layer is filled into a loose structure with certain space stability, a larger space is provided for the space residence of osteoblasts, and meanwhile, the contact area between the osteoblasts and nutrient substances can be greatly improved by the porous lattice structure, so that the stronger activity of the cells can be ensured, and the prosthesis and the skeleton can be more firmly combined.

In addition, both ends of the inner filler 3 do not extend into the fusion zone 102, that is, after the inner filler 3 is initially implanted, the inner filler does not directly contact the bone, so that the bone does not collapse due to point contact, but the inner filler is integrated with the bone after the blood flows into the inner filler and osteoblasts form bone, thereby improving the mechanical strength of the limb.

The above is only a preferred embodiment of the invention, and any simple modifications, variations and equivalents of the invention may be made by anyone in light of the above teachings and fall within the scope of the invention.

Claims

1. Individual customization formula long bone defect fills uses bionical transplantation bone piece, has biocompatibility, its characterized in that, is the columnar structure of multilayer, includes from outside to inside:

2. The biomimetic bone graft according to claim 1, wherein the end surface of the fusion portion that contacts the contiguous cortical bone is a granular surface.

3. The biomimetic bone graft according to claim 1, wherein each porous cell unit is a hexahedron composed of two triangular pyramids, each hexahedron composed of six compact rods, and a plurality of porous cell units are stacked on top of each other.

4. The biomimetic bone graft of claim 1, wherein the biomimetic bone graft is integrally formed using 3D printing.

5. The biomimetic bone graft according to claim 1, wherein the length of the connecting portion is 5-300 mm.

6. A biomimetic bone graft as in claim 1, wherein the fusion portion is topologically optimized, having an inner annular wall and an outer annular wall, with a plurality of axially spaced apart spacers therebetween, with raised posts on either end of the spacer.

7. A biomimetic bone graft according to claim 6, wherein the outermost spacer on the proximal connector is lower than the inner and outer annular walls to define a reservoir.

8. A biomimetic bone graft according to claim 6, wherein the inner annular wall of the proximal connecting portion has a notch.

9. The biomimetic bone graft according to claim 1, wherein the side wall of the middle filling body has a through notch.

10. The biomimetic bone graft of claim 1, wherein the voids in the fusion are smaller than the voids in the middle filler.