NL2032323A

NL2032323A - A bone integrated prosthesis material for 3d printing, a prosthesis and a surface processing method thereof

Info

Publication number: NL2032323A
Application number: NL2032323A
Authority: NL
Inventors: Shi Yan; Zhao Xuelin; Xu Meng; Ji Tao
Original assignee: The Fourth Medical Center Of Pla General Hospital
Priority date: 2021-11-30
Filing date: 2022-06-29
Publication date: 2023-05-23
Also published as: CN114191606A; NL2032323B1; CN114191606B

Abstract

The disclosure discloses a porous bone integrated prosthesis material for 3D printing and a prosthesis. The prosthesis is obtained by 3D printing from Al-Mg alloy. In order to improve the integration effect, shorten the integration period and reduce the infection rate, the porous bone integrated prosthesis is subjected to surface processing, including spraying of tiny tantalum metal particles and hydroxyapatite by high-speed shot peening and electrolytic polishing, so that the porous bone integrated prosthesis material has the characteristics of anti-infection, easy integration and reduced cost.

Description

[DESCRIPTION] [Title of Invention]

A BONE INTEGRATED PROSTHESIS MATERIAL FOR 3D PRINTING, A

PROSTHESIS AND A SURFACE PROCESSING METHOD THEREOF

[ Technical Field]

The disclosure relates to medical devices, and more particularly to a bone mtegrated prosthesis material for 3D printing, a prosthesis and a surface processing method thereof. [Background Art]

By the end of 2020, the total population of 230 countries in the world has reached 7.6 billion, and with the accelerating process of population aging and the mcreasing number of traumatic diseases, a large number of people in the world have their upper and lower limbs amputated to save their lives due to work-related injuries, diseases, traffic accidents, wars and other factors every year, but the ability to move and walk is impaired, which seriously affects the work and life of patients, and brings great burden to their psychology, family and society. In order to fit in normal life and work, amputees usually need to wear prosthesis to achieve the reconstruction of walking motion function. The traditional prosthesis is a shell prosthesis that uses a prosthetic socket to connect with the prosthesis outside the amputated stump. This kind of prosthesis is difficult to meet the biomechanical requirements because the prosthetic socket cannot evenly distribute the bearing, and often causes skin inflammation or even rupture due to uneven local force and friction. In addition, due to the closed prosthetic socket, local sweating and odor are often caused, which seriously affects the quality of life of patients. A series of disadvantages of the shell prosthesis call for clinical and scientific researchers to propose a more biomechanical and convenient prosthetic design as soon as possible. In the 1950s, Professor Branemark of Sweden found that it is difficult to remove titanium after it is inserted into the rabbit femur for a certain period of time, and the bone and metal were well anchored. He defined this combination as the integration of prosthesis and bone: that is, the implant had a persistent bone contact with active bone tissue. The traditional prosthetic socket is removed from the implantable bone integrated prosthesis. The implantable bone integrated prosthesis draws on the experience of the technology of dental implants, one end is inserted into the stump bone cavity, and the other end protrudes through the skin to connect with the prosthesis. This kind of residual limb fundamentally solves the problems that traditional prosthesis produces foul odor due to the poor permeability of the interface between the socket and the residual limb, and the residual limb infection caused by friction, and so on.

Artificial implants are often used in surgical procedures to replace the disability parts of patients. Clinically, metal materials are often used as implant parts, including titanium alloy, stainless steel, and cobalt-chromium alloys They are mainly used as artificial joints, bone substitutes, etc. to replace the damaged or diseased hard tissue of patients. Stainless steel is a metal medical implant material with earlier development and low material cost, which once occupied a large part of the medical metal implant market. However, due to the high density of stainless steel, strong foreign body sensation in patients, and poor corrosion resistance of Fe, large cytotoxic side effects of

Ni and Cr ions released by wear during use, and other factors, the scale of its application in the implant market is shrinking. With the update and development of biomedical alloys, titanium and titanium alloy products with better biocompatibility have been widely used in bone tissue repair in recent years. However, the elastic modulus of titanium and its alloy products is quite different from that of human bones, which will lead to the so-called "stress shielding" effect, which will lead to bone absorption around the implant in the long run, even lead to the slip of the implant, and reduce the success rate of bone implantation.

Aiming at the problems of large elastic modulus of existing bone integrated prosthesis materials, long integration period and high cost, a porous bone integrated prosthesis material for 3D printing and a prosthesis are proposed. In order to improve the integration effect, shorten the integration period and reduce the infection rate, surface processing for the porous bone integrated prosthesis is performed, including spraying tiny tantalum metal particles and hydroxyapatite by high-speed shot peening, and electrolytic polishing, so that the porous bone integrated prosthesis material has the characteristics of anti-infection, easy bone integration and reduced cost. [Disclosure of Invention}

In view of this, the present disclosure provides a porous bone integrated prosthesis material for 3D printing and a prosthesis and a surface processing method for the prosthesis. The present disclosure uses Al-Mg alloy as the prosthesis material, and

Al-Mg alloy has a low melting point, so that the 3D printing temperature can be reduced, and the printing speed and curing speed can be improved, and the productivity can be improved.

In order to achieve the above object, the present disclosure adopts the following technical solutions:

A porous bone integrated prosthesis material for 3D printing, the bone integrated prosthesis material is Al-Mg alloy.

Preferably, the mass ratio of Al to Mg in the Al-Mg alloy is (1:5) > (5:1).

The beneficial effects brought by the above optimization are: the elastic modulus of human cortical bone 1s 10~30GPa, and the elastic modulus of the solid Al-

Mg alloy is about 40GPa, and there is little difference between the two, thereby preventing the "stress shielding" effect, increasing the firmness of the integration and preventing the prosthesis from loosening.

Another object of the present disclosure 1s to provide a 3D printed porous bone mtegrated prosthesis, the bone integrated prosthesis 1s made from the above-mentioned bone integrated prosthesis material by 3D printing, and argon is used as the protective gas during the 3D printing process, and the temperature is set to 650~750°C, the printing speed is set to 20-200mm/s.

Preferably, the porosity of the bone integrated prosthesis 1s 20-80%.

When the porosity of the bone integrated prosthesis is 20-80%, its elastic modulus is not much different from that of human bone, which can prevent the "stress shielding" effect, increase the firmness of the integration, and make bone tissue grow into the pores to achieve better integration effect.

Another object of the present disclosure is to provide the above-mentioned surface processing method for the 3D printed porous bone integrated prosthesis, comprising the following steps: (1) High-speed shot peening

Ultrasonic cleaning, drying and shot peening of the bone integrated prosthesis; after shot peening, observing the spray coating under a microscope to make the coating dense and achieve the effect of antibacterial and isolating the Al-Mg metal layer; (2) Electrolytic polishing

Performing electrolytic polishing on the bone integrated prosthesis with rough surface after shot peening.

Preferably, cleaning agent in the ultrasonic cleaning is absolute ethanol, ultrasonic frequency is 10-50 KHz, processing time is 0.5-2 hours, and after the ultrasonic cleaning, drying in the drying oven for 5-10 minutes.

Preferably, the shot peening includes ball milling tantalum powder and hydroxyapatite with a mass ratio of (1:3) to (3:1) into particles of 50-200 um, and then shot peening all surfaces of the bone integrated prosthesis. The thickness of the spray coating is 200-500 um.

Preferably, in the electrolytic polishing, the electrolyte is an HNO: solution with a volume fraction of 4%, temperature of the electrolyte is 20-30°C, DC current is 3- 15V, and polishing time is 15-20 minutes.

As can be seen from the above-mentioned technical solutions, compared with the prior art, the present disclosure has the following beneficial effects: 1. the porous bone integrated prostheses made of Al-Mg alloy material by 3D printing can save the cost to a certain extent, and the elastic modulus of Al-Mg alloy is not much different from that of human bone, which can avoid the stress shielding effect, make the prosthesis more closely integrated with human bone tissue, and can also avoid the phenomenon of detachment after integration. 2. the melting point of Al-Mg alloy is low, 3D printing temperature is set low, and printing speed and curing speed can be improved, which can improve the production efficiency.

3. on one hand, the shot peening and electrolytic polishing on the surface of the 3D printed porous bone integrated prosthesis can isolate the contact between Al-Mg alloy and bone tissue, and on the other hand, tantalum particles and hydroxyapatite have good biological properties and can resist infection. Also, the shot peening and 5 electrolytic polishing can improve the surface finish of porous prosthesis, which further reduce infection rate. [Brief Description of Drawings]

In order to illustrate the embodiments of the present disclosure or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawing that is used in the description of the embodiments or the prior art. Obviously, the drawing in the following description is only an embodiment of the present disclosure. For those of ordinary skill in the art, other drawings can also be obtained according to the provided drawing without creative work.

Fig. 1 1s the flow chart of the method of the present disclosure. [Mode for the Invention]

The technical solutions in the embodiments of the present disclosure will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by those skilled m the art without creative work should fall within the protection scope of the present disclosure.

Embodiment 1

A 3D printed bone integrated prosthesis is made by: selecting Al powder and Mg powder with a mass ratio of (2:5), mixing the Al powder and Mg powder and ball milling to a particle size of about 200 um, putting it into a powder feeder of a 3D printer, setting temperature to 680 °C, setting printing speed to 40mm/s, and performing 3D printing. During the whole printing process,

protecting by argon. Finally, a bone integrated prosthesis with a diameter of 8mm and a porosity of 50% 1s prepared.

In order to make the surface of the bone integrated prosthesis more smoothly, the prepared bone integrated prosthesis may be electrolytic polished. The electrolyte is

HNO: solution with a volume fraction of 4%, the electrolyte temperature is 20 °C, the electrolytic voltage 1s 5V DC, and the polishing time is 15 minutes.

After electrolytic polishing, the bone integrated prosthesis may be cleaned with absolute ethanol. The ultrasonic frequency 1s 10KHz, and the processing time 1s 0.5 hours. After ultrasonic cleaning, it may be placed m a drying box and dried for 10 minutes. The surface quality of the bone integrated prosthesis can be tested. If there are no pores, surface cracks and defects, they are qualified products. Then, the tensile and compressive mechanical properties of the bone integrated prosthesis may be tested on the universal testing machine. The tensile and compression rates are both set to

Imm/min. The elastic modulus of the prosthesis measured in the experiment is 38.4

GPA, which is close to the elastic modulus of human bone, indicating that the preparation 1s successful.

Embodiment 2

Selecting Al powder and Mg powder with a mass ratio of (1:5), mixing the Al powder and Mg powder and ball milling to a particle size of about 200 um, putting it into the powder feeder of the 3D printer, setting the temperature to 650 °C, setting the printing speed to 20mm/s, and performing 3D printing. During the whole printing process, protecting by argon. Finally, a bone integrated prosthesis with a diameter of 8mm and a porosity of 20% is prepared.

High-speed shot peening may be performed on the surface of the prosthesis. The shot peening particles are ball-milled hydroxyapatite particles with a particle size of 80 um and a shot peening layer has a thickness of 100 um. In order to make the surface of the bone integrated prosthesis more smoothly, the prepared bone integrated prosthesis may be electrolytic polished. The electrolyte 1s HNO: solution with a volume fraction of 4%, the electrolyte temperature is 20 °C, the electrolytic voltage is 5V DC, and the polishing time is 15 minutes.

GPA, which is close to the elastic modulus of human bone, indicating that the preparation is successful.

Embodiment 3

Selecting Al powder and Mg powder with a mass ratio of (5:1), mixing the Al powder and Mg powder and ball milling to a particle size of about 200 um, putting it into the powder feeder of the 3D printer, setting the temperature to 680 °C, setting the printing speed to 200mm/s, and performing 3D printing. During the whole printing process, protecting by argon. Finally, a bone integrated prosthesis with a diameter of 8mm and a porosity of 80% is prepared.

High-speed shot peening is performed on the surface of the prosthesis. The shot peening particles are ball-milled hydroxyapatite particles with a particle size of 100 pm and a shot peening layer has a thickness of 50 um. In order to make the surface of the bone integrated prosthesis more smoothly, the prepared bone integrated prosthesis may be electrolytic polished. The electrolyte is HNO; solution with a volume fraction of 4%, the electrolyte temperature is 30 °C, the electrolytic voltage is 15V DC, and the polishing time is 20 minutes.

After electrolytic polishing, the bone integrated prosthesis may be cleaned with absolute ethanol. The ultrasonic frequency is 50K Hz, and the processing time is 2 hours.

After ultrasonic cleaning, it may be placed in a drying box and dried for 10 minutes.

The surface quality of the bone integrated prosthesis can be tested. If there are no pores, surface cracks and defects, they are qualified products. Then, the tensile and compressive mechanical properties of the bone integrated prosthesis may be tested on the universal testing machine. The tensile and compression rates are both set to

Each embodiment 1n this specification is described 1n a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the various embodiments can be referred to each other. As for the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and please refer to the description of the method section for relevant parts.

The above description of the disclosed embodiments enables those skilled in the art to implement or use the present disclosure. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Thus, the present disclosure 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.

Claims

Conclusions

IL. Porous bone-integrated prosthetic material for 3D printing, where the bone-integrated prosthetic material is Al-Mg alloy.

The cancellous bone-integrated prosthetic material for 3D printing according to claim 1, wherein the mass ratio of Al to Mg in the Al-Mg alloy is (1:5) ~ (5:1)

is.

A 3D printed cancellous bone-integrated prosthesis, wherein the bone-integrated prosthesis is made of the cancellous bone-integrated prosthetic material according to claim 1 or 2 by 3D printing and argon is used as a shielding gas during the process of 3D printing, the temperature is set to 650 — 750 °C and the print speed is 20 — 200 mm/s.

The 3D printed cancellous bone-integrated prosthesis according to claim 3, wherein the porosity of the bone-integrated prosthesis is 20-80%.

A surface processing method for the 3D printed cancellous bone-integrated prosthesis made according to claim 4, comprising the steps of: (1) high-speed shot peening, ultrasonic cleaning, drying and beading of the bone-integrated prosthesis; (2) electropolishing performing electropolishing on the bone-integrated prosthesis having a rough surface after bead blasting.

The surface processing method for the 3D printed cancellous bone-integrated prosthesis according to claim 5, wherein the cleaning agent during ultrasound cleaning is absolute ethanol, the frequency of the ultrasound is 10-50 kHz, the processing time is 0.5-2 hours and dry in the drying oven for 5 — 10 minutes after cleaning with ultrasound.

The surface processing method for the 3D printed cancellous bone-integrated prosthesis of claim 5, wherein it comprises bead-milling with a ball mill of tantalum powder and hydroxyapatite at a mass ratio of (1:3) to (3:1) to particles of 50 to 200 um, and then bead blasting on all surfaces of the bone-integrated prosthesis, with the thickness of the spray coating being 200~500 um.

The surface processing method for the 3D printed cancellous bone-integrated prosthesis according to claim 5, wherein during the electrolytic polishing, the electrolyte is a solution of HNO: with a volume fraction of 4%, the temperature of the electrolyte is 20-30°C , DC 3 — 15 Vis and the polishing time is 15 — 20 minutes.