阅读说明：本技术 一种多材料多孔股骨远端植入体及其制造方法 (Multi-material porous femur distal implant and manufacturing method thereof ) 是由 宋长辉 雷浩杨 余家阔 刘子彬 杨永强 于 2020-12-18 设计创作，主要内容包括：本发明公开了一种多材料多孔股骨远端植入体及其制造方法,植入体包括硬质梯度多孔股骨远端植入躯干以及软质水凝胶软骨；所述硬质梯度多孔股骨远端植入躯干为多孔结构,外轮廓分为锥型的股骨体以及两个类球形的仿股骨踝；所述软质水凝胶软骨为两个半圆环状覆盖物,分别覆盖在所述两个仿股骨踝上。本发明采用硬质材料和软质材料相结合的仿生设计,能够最大程度的模仿人体正常股骨远端的结构组成,通过采用软质材料和相对应的干细胞组合的方式,可通过组织工程,在植入后刺激其生成毛细血管,提高植入体在人体中的适应性。并且,采用羟基磷灰石和钛合金结合的方式,能够避免单材料羟基磷灰石植入体存在的脆性问题。(The invention discloses a multi-material porous femur far-end implant and a manufacturing method thereof, wherein the implant comprises a hard gradient porous femur far-end implant trunk and a soft hydrogel cartilage; the trunk of the hard gradient porous distal femur implant is of a porous structure, and the outer contour of the hard gradient porous distal femur implant is divided into a conical femoral shaft and two spheroidal simulated femoral ankles; the soft hydrogel cartilage is two semicircular annular covers which are respectively covered on the two simulated femoral ankles. The bionic design combining hard materials and soft materials is adopted, the structure composition of the far end of the normal femur of a human body can be simulated to the greatest extent, and the soft materials and the corresponding stem cells are combined, so that capillary vessels can be stimulated to generate after the soft materials are implanted through tissue engineering, and the adaptability of the implant in the human body is improved. In addition, the brittleness problem of the single-material hydroxyapatite implant can be avoided by adopting a mode of combining the hydroxyapatite and the titanium alloy.)

1. A multi-material porous distal femoral implant comprising a hard gradient porous distal femoral implant trunk and a soft hydrogel cartilage;

the trunk of the hard gradient porous distal femur implant is of a porous structure, and the outer contour of the hard gradient porous distal femur implant is divided into a conical femoral shaft and two spheroidal simulated femoral ankles;

the soft hydrogel cartilage is two semicircular annular covers which are respectively covered on the two simulated femoral ankles.

2. The multi-material porous femoral distal implant according to claim 1, wherein the soft hydrogel cartilage is divided into an outer layer and an inner layer according to the difference of components; the outer layer is a soft cartilage layer, and the components of the outer layer are hydrogel, peripheral blood stem cells and peripheral blood stem cell growth factors;

the inner layer is in contact with the simulated femoral condyle and is a hard cartilage layer, the components of the inner layer are hydroxyapatite and hydrogel, the content of the hydroxyapatite is in gradient change, the content range is 10% -40%, and the closer to the simulated femoral condyle, the higher the content of the hydroxyapatite is.

3. The multi-material porous femoral distal implant according to claim 1, wherein the porous structure is a bionic gradient porous structure, and is divided into a plurality of porous structure units by taking a regular octahedron as a topology, and each porous structure unit is communicated with each other.

4. The multi-material porous femoral distal implant according to claim 3, wherein the inner pore diameter of the porous structure unit is continuously changed in a gradient manner from the center to the edge, and is gradually reduced from 500 microns to 200 microns on any horizontal section of the hard gradient porous femoral distal implant trunk.

5. The multi-material porous femoral distal implant according to claim 4, wherein said hard gradient porous femoral distal implant stem is made of hydroxyapatite and titanium alloy; the porous structure unit with the inner hole diameter of 500 microns adopts hydroxyapatite, and the porous structure unit with the inner hole diameter of 200 microns and 300 microns adopts titanium alloy.

6. The multi-material porous femoral distal implant according to claim 5, wherein the surface of said hard graded porous femoral distal implant stem is covered with porous titanium oxide and calcium hydroxy phosphate coating.

7. The method of manufacturing a multi-material porous femoral distal implant of claim 1, comprising the steps of:

performing three-dimensional reconstruction on the femur far end of a patient by using medical image processing software according to continuous tomography data obtained by CT or MRI scanning of the patient; processing the obtained object in medical image processing software to obtain a hard femur far-end CAD model and a cartilage CAD model;

designing octahedral porous structure units with different sizes according to bone conditions of different areas in a medullary cavity of the distal femur of an actual patient, and then performing Boolean operation on the octahedral porous structure units and the obtained hard distal femur CAD model to obtain a hard gradient porous distal femur implanted trunk CAD model; according to the bone condition of the far-end femur cartilage of the patient, topologically optimizing the obtained cartilage CAD model to obtain a soft hydrogel cartilage CAD model;

implanting the obtained hard gradient porous femur far end into a trunk CAD model, introducing the hard gradient porous femur far end into slicing software of laser selective melting 3D printing equipment, adding printing supports and setting printing parameters, and generating corresponding slicing files;

importing the obtained soft hydrogel cartilage CAD model into in-situ 3D printing equipment slicing software, and generating a corresponding slicing file after setting corresponding printing parameters;

guiding a slice file generated by slice software of the selective laser melting 3D printing equipment into the selective laser melting 3D printing equipment to perform additive manufacturing of the hard gradient porous femur far-end implanted trunk;

after the hard gradient porous femur far end is implanted into the trunk and printed, disinfecting the trunk, and then implanting the hard gradient porous femur far end into the trunk for micro-arc oxidation to form a porous titanium oxide and calcium hydroxy phosphate coating on the surface of the trunk;

implanting the obtained hard gradient porous femur far end into a trunk, placing the trunk into in-situ 3D printing equipment, introducing a slice file generated by slice software of the in-situ 3D printing equipment, and performing in-situ printing to form a soft hydrogel cartilage part.

8. The manufacturing method according to claim 7, wherein the medical image processing software is processed by:

and separating the corresponding cartilages of the hard femur far end and the femur far end of the patient through threshold division to respectively obtain a hard femur far end CAD model and a cartilage CAD model.

9. The manufacturing method according to claim 7, wherein the in-situ printing to form the soft hydrogel cartilage portion is specifically:

through in-situ printing, covering a hard cartilage layer consisting of hydrogel and hydroxyapatite on the surface of a trunk implanted at the far end of the hard gradient porous femur;

and covering a soft cartilage layer consisting of hydrogel, peripheral blood stem cells and peripheral blood stem cell growth factors on the hard cartilage layer by in-situ printing.

10. The manufacturing method according to claim 7, characterized in that the medical image processing software is in particular a Mimic;

the slicing software of the laser selective melting 3D printing equipment is concretely Magic;

the slicing software of the in-situ 3D printing equipment is specifically Cura15.0.

Technical Field

The invention belongs to the technical field of additive manufacturing, and particularly relates to a multi-material porous femur distal implant and a manufacturing method thereof.

Background

The femur, which is the longest long tubular bone of the human body, bears most of the load from the upper half of the human body, and is one of the most important bones of the human body. While the femur is extremely susceptible to fractures due to some disease or trauma, which are often unrecoverable by itself, the best treatment is to replace the defect portion by femoral replacement surgery.

The most commonly used femoral prostheses for replacement are single-material implants, which are usually made of a hard material, such as a metallic material (titanium and its alloys) or bioceramic (calcium hydroxy phosphate, zirconia). The implant is usually just used as a hard bionic femur to be implanted into a human body, and the implant made of pure ceramic materials is very brittle, has poor mechanical properties and is easy to break, while the titanium alloy-based material is easy to generate stress shielding because the Young modulus of the titanium alloy-based material cannot be matched with natural bones, so that the implant is loosened. In addition, the cartilage part of the femur can only be used as a substitute of the cartilage by using high molecular polymers such as polyetheretherketone resin, and the substitute can only reduce the friction between the femoral implant and the natural bone, but cannot really realize the function of the cartilage, and the cartilage is easy to fall off by chemical bonding, so that the risk of postoperative revision is caused.

Disclosure of Invention

The invention mainly aims to overcome the defects of the prior art and provides a multi-material porous femur distal implant and a manufacturing method thereof.

In order to achieve the purpose, the invention adopts the following technical scheme:

a multi-material porous femur far-end implant is integrally formed by a 3D printing technology and comprises a hard gradient porous femur far-end implant trunk and a soft hydrogel cartilage;

the trunk of the hard gradient porous distal femur implant is of a porous structure, and the outer contour of the hard gradient porous distal femur implant is divided into a conical femoral shaft and two spheroidal simulated femoral ankles;

the soft hydrogel cartilage is two semicircular annular covers which are respectively covered on the two simulated femoral ankles.

Further, the soft hydrogel cartilage is divided into an outer layer and an inner layer according to the difference of components; the outer layer is a soft cartilage layer, and the components of the outer layer are hydrogel, peripheral blood stem cells and peripheral blood stem cell growth factors;

the inner layer is in contact with the simulated femoral condyle and is a hard cartilage layer, the components of the inner layer are hydroxyapatite and hydrogel, the content of the hydroxyapatite is in gradient change, the content range is 10% to 40%, and the closer to the simulated femoral condyle, the higher the content of the hydroxyapatite is.

Furthermore, the porous structure is a bionic gradient porous structure, takes an octahedron as a topology, is divided into a plurality of porous structure units, and each porous structure unit is communicated with each other.

Furthermore, on any horizontal section of the trunk implanted at the distal end of the hard gradient porous femur, the diameter of an inner hole of the porous structure unit is continuously changed in a gradient manner, specifically, the diameter of the inner hole is gradually reduced from the center to the edge and is reduced from 500 micrometers to 200 micrometers.

Furthermore, the trunk of the distal implantation of the hard gradient porous femur adopts hydroxyapatite and titanium alloy; the porous structure unit with the inner hole diameter of 500 microns adopts hydroxyapatite, and the porous structure unit with the inner hole diameter of 200 microns and 300 microns adopts titanium alloy.

Further, the surface of the hard gradient porous femur far-end implantation trunk is covered with porous titanium oxide and a calcium hydroxy phosphate coating.

The invention also includes a method of manufacturing a multi-material porous femoral distal implant, comprising the steps of:

performing three-dimensional reconstruction on the femur far end of a patient by using medical image processing software according to continuous tomography data obtained by CT or MRI scanning of the patient; processing the obtained object in medical image processing software to obtain a hard femur far-end CAD model and a cartilage CAD model;

designing octahedral porous structure units with different sizes according to bone conditions of different areas in a medullary cavity of the distal femur of an actual patient, and then performing Boolean operation on the octahedral porous structure units and the obtained hard distal femur CAD model to obtain a hard gradient porous distal femur implanted trunk CAD model; according to the bone condition of the far-end femur cartilage of the patient, topologically optimizing the obtained cartilage CAD model to obtain a soft hydrogel cartilage CAD model;

implanting the obtained hard gradient porous femur far end into a trunk CAD model, introducing the hard gradient porous femur far end into slicing software of laser selective melting 3D printing equipment, adding printing supports and setting printing parameters, and generating corresponding slicing files;

importing the obtained soft hydrogel cartilage CAD model into in-situ 3D printing equipment slicing software, and generating a corresponding slicing file after setting corresponding printing parameters;

guiding a slice file generated by slice software of the selective laser melting 3D printing equipment into the selective laser melting 3D printing equipment to perform additive manufacturing of the hard gradient porous femur far-end implanted trunk;

after the hard gradient porous femur far end is implanted into the trunk and printed, disinfecting the trunk, and then implanting the hard gradient porous femur far end into the trunk for micro-arc oxidation to form a porous titanium oxide and calcium hydroxy phosphate coating on the surface of the trunk;

implanting the obtained hard gradient porous femur far end into a trunk, placing the trunk into in-situ 3D printing equipment, introducing a slice file generated by slice software of the in-situ 3D printing equipment, and performing in-situ printing to form a soft hydrogel cartilage part.

Further, the medical image processing software is specifically processed as follows:

and separating the corresponding cartilages of the hard femur far end and the femur far end of the patient through threshold division to respectively obtain a hard femur far end CAD model and a cartilage CAD model.

Further, the in-situ printing to form the soft hydrogel cartilage part specifically comprises:

through in-situ printing, covering a hard cartilage layer consisting of hydrogel and hydroxyapatite on the surface of a trunk implanted at the far end of the hard gradient porous femur;

and covering a soft cartilage layer consisting of hydrogel, peripheral blood stem cells and peripheral blood stem cell growth factors on the hard cartilage layer by in-situ printing.

Further, the medical image processing software is specifically Mimic;

the slicing software of the laser selective melting 3D printing equipment is concretely Magic;

the slicing software of the in-situ 3D printing equipment is specifically Cura15.0.

Compared with the prior art, the invention has the following advantages and beneficial effects:

1. the bionic design combining hard materials and soft materials is adopted, the structure composition of the far end of the normal femur of a human body can be simulated to the greatest extent, and the soft materials and the corresponding stem cells are combined, so that capillary vessels can be stimulated to generate after the soft materials are implanted through tissue engineering, and the adaptability of the implant in the human body is improved.

2. The invention can realize the control of the Young modulus of the implant by adopting the gradient porous structure design and controlling the inner diameter of the marrow-like porous structure in the hard gradient porous trunk. Different gradient porous structure inner diameters are designed according to the Young modulus of different areas of the femur far end of an actual patient, so that the Young modulus of the implant can be close to the femur far end of the patient, the stress shielding phenomenon caused by the overlarge Young modulus of the solid implant can be effectively reduced, the implant looseness caused by stress redistribution is reduced, and the possibility of postoperative revision is reduced.

3. The invention can avoid the brittleness problem of single material hydroxyapatite implant by adopting the mode of combining the hydroxyapatite and the titanium alloy. The titanium alloy used as the exterior can improve the toughness of the whole implant and improve the fracture resistance of the implant. In addition, the titanium alloy surface is covered with hydroxyapatite again through micro-arc oxidation, so that the compatibility of the implant and a human body is improved.

4. The method adopts the combination of selective laser melting additive manufacturing and in-situ 3D printing technology, and can realize multi-material one-step molding of the multi-material porous femur distal implant; through selective melting of laser, can make the complicated structure of implant hard metal, print through normal position 3D, can be directly at the local direct cover that the thighbone ankle needs soft materials, and need not subsequent manual bonding, precision and efficiency that can the porous distal femur implant of effectual improvement many materials made.

Drawings

FIG. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a schematic view of the porous structure of the present invention;

FIG. 3 is an arrangement of the gradient porous structure of the present invention in a horizontal section;

FIG. 4 is a flow chart of the method of the present invention;

the reference numbers illustrate: 1-a hard metal alloy gradient porous torso; 2-soft cartilage layer; 3-hard cartilage layer; 4-titanium alloy porous structure; 5-hydroxyapatite porous structure.

Detailed Description

The present invention will be described in further detail with reference to examples and drawings, but the present invention is not limited thereto.

Examples

As shown in fig. 1, the multi-material porous distal femoral implant of the present invention comprises a hard gradient porous distal femoral implant trunk 1 and a soft hydrogel cartilage, wherein the hard gradient porous distal femoral implant trunk 1 has a porous structure, and has an outer contour comprising a conical femoral body and two spheroidal femoral condyles; the soft hydrogel cartilage is two semicircular annular coverings, is integrally butterfly-shaped and respectively covers the two imitated femoral ankles; the hard gradient porous femur far end is implanted into a trunk and mainly used as a bionic femur to be implanted into the femur far end of a patient, the surface of the femur far end is coated with the microporous titanium oxide and the calcium hydroxy phosphate coating through micro-arc oxidation, cells can be effectively stimulated to attach to the surface of an implant, the possibility that bacteria attach to the surface of the implant is reduced, and postoperative infection is avoided; the soft hydrogel cartilage is divided into two parts, namely a soft cartilage layer 2 and a hard cartilage layer 3 according to different main components, and after the soft hydrogel cartilage is implanted into a human body, the direct contact between a femoral condyle and inner and outer side terraces of a tibia can be avoided, the abrasion of the inner and outer side terraces of the tibia is prevented, and the tibia is protected.

In this embodiment, the main components of the soft cartilage layer are hydrogel, peripheral blood stem cells and peripheral blood stem cell growth factors, which can enable the soft part of the implant to generate capillaries through tissue engineering, thereby realizing material communication with the natural bone part and preventing subsequent local necrosis at the implanted opening; the hard cartilage layer is a cartilage part implanted into the trunk near the distal end of the hard gradient porous femur, the main components of the hard cartilage layer are hydroxyapatite and hydrogel, the content of the hydroxyapatite is in gradient change, the content range is 10-40%, the content of the hydroxyapatite near one side of the femoral condyle is higher, and the hardness is higher.

In this embodiment, as shown in fig. 2, the porous structure is specifically a bionic gradient porous structure, and is divided into a plurality of porous structure units by taking an octahedron as a topology, and each porous structure unit is communicated with each other. The length of the octahedral column is changed, so that the pore size of the porous structure is controlled within 200-500 mu m, and the mechanical property of the whole structure is controlled.

As shown in fig. 3, in the bionic gradient porous structure, under any horizontal section of the trunk implanted with the distal end of the hard gradient porous femur, the size distribution of the whole gradient porous pores tends to decrease from the middle to the periphery, and the porous structures in different areas are matched with the young modulus of the femur density of the area of an actual patient; the porous structure with the outer edge inner hole diameter of 200-300 microns is a titanium alloy porous structure 4, and the porous structure unit with the middle inner hole diameter of 500 microns is a hydroxyapatite porous structure 5.

The brittleness of the pure ceramic material implant or the overhigh Young modulus of the pure titanium alloy implant can be avoided by using the titanium alloy as the outer wall and the hydroxyapatite as the center. Through the design of the gradient porous structure, the final Young modulus of the whole porous structure is controlled within 1.3-18 GPa, so that the high-hardness distal femur implant matched with the Young modulus of the natural femur of a human body is obtained.

The invention also includes a method for manufacturing the multi-material porous femoral distal implant, as shown in fig. 4, comprising the steps of:

and S1, performing three-dimensional reconstruction on the distal femur of the patient by using Mimic software according to the continuous tomography data obtained by CT/MRI scanning of the patient. In the Mimic software, the hard femur far end and the corresponding cartilage of the femur far end of a patient are separated through threshold division, and a hard femur far end CAD model and a cartilage CAD model are respectively obtained.

S2, designing octahedral porous units with different sizes according to bone conditions of different areas in the medullary cavity of the distal femur of an actual patient, and then performing Boolean operation on the octahedral porous units and the hard femur distal end CAD model obtained in the step S1 to obtain a hard gradient porous femur distal end implanted trunk CAD model; then according to the bone condition of the far-end femur cartilage of the patient, the cartilage CAD model obtained in the step S1 is topologically optimized to obtain a soft hydrogel cartilage CAD model

And S3, implanting the distal end of the hard gradient porous metal femur obtained in the step S2 into a trunk CAD model, introducing the distal end into slice software Magic of laser selective melting 3D printing equipment, adding printing supports, setting printing parameters, and generating a corresponding slc file.

S4, importing the soft hydrogel cartilage CAD model obtained in the S2 into cutting software Cura15.0 of an in-situ 3D printing device, and generating a Gcode file after setting corresponding printing parameters

And S5, importing the slc file obtained in the step S3 into a laser selective melting 3D printing device to perform additive manufacturing of the hard gradient porous metal femur far-end implanted trunk.

S6, after the distal end of the hard gradient porous metal femur is implanted into the trunk and printed, the trunk is disinfected, and then the distal end of the hard gradient porous metal femur is implanted into the trunk to be subjected to micro-arc oxidation, so that a porous titanium oxide and calcium hydroxy phosphate coating is formed on the surface of the distal end of the hard gradient porous metal femur.

S7, implanting the distal end of the hard gradient porous metal femur obtained in the step S6 into a trunk, putting the trunk into an in-situ 3D printing device, introducing the Gcode file obtained in the step S4, and performing in-situ printing. Through in-situ printing, a hard cartilage layer consisting of hydrogel and hydroxyapatite is covered on the surface of a trunk implanted at the far end of the hard gradient porous metal femur; and finally, covering a soft cartilage layer consisting of hydrogel, peripheral blood stem cells and peripheral blood stem cell growth factors on the hard cartilage layer by an in-situ printing technology to form a soft hydrogel cartilage part.

It should also be noted that in this specification, terms such as "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.