Original Title: Development and Application of Medical Titanium and Titanium
Alloys for Surgical Implants 1. Introduction Titanium and its alloys used as
surgical implants have many advantages, such as low density, high strength, good
toughness, good biocompatibility, non-toxic, low elastic modulus, good corrosion
resistance, low X-ray absorption rate and so on, so they play an increasingly
important role in medical metal materials. Titanium and its alloys can be used
for the repair and replacement of human hard tissues, or for the repair of
cardiovascular and soft tissues and the manufacture of artificial organs. They
are special functional materials closely related to human life and health. At
present, it has become the preferred metal material for replacement or repair of
artificial joints, artificial bones, broken bone bindings, spinal correction
rods, intramedullary nails, artificial heart valves, dental implants, skull and
other products. The world's population is nearly 6.5 billion, and the global
aging problem is very serious. According to the data of F & S Company, the
compound growth rate of the global orthopaedic implant device market in the past
five years is about 10.4%, which is expected to reach 27.7 billion US dollars by
2015, while the Chinese orthopaedic implant device market will grow to 16.6
billion US dollars, with a compound annual growth rate of 18.1%. It can be seen
that titanium and its alloys are the preferred materials for medical metal
materials, and their future market demand is very strong. Therefore, it is of
great significance to increase the research and development and application
promotion of medical titanium and its alloys in China. 2. Research and
development status of titanium materials for surgical implants 2.1 Vanadium-free
medical titanium alloy Ti-6Al-7Nb alloy is a medical alloy developed by Sulzer
Medical Technology Company in Switzerland. Compared with Ti-6Al-4V alloy, the
properties of Ti-6Al-7Nb alloy are equal to that of Ti-6Al-4V alloy, which is a
safe and potential material for human implantation. Many kinds of Ti-6Al-7Nb
alloy implants have been put into clinical application with good results.
Another medical titanium alloy, Ti-5Al-2.5Fe, was developed by Germany. Compared
with Ti-6Al-4V alloy, vanadium is replaced by cheap and non-toxic iron element.
Ti-5Al-2. 5Fe is a medium-strength material, which is equivalent to Ti-6Al-4V in
terms of mechanical property,titanium
round bar, toughness and fatigue strength. These two alloys have also been
developed in China. Ti-6Al-7Nb and Ti-5Al-2.5Fe alloys have been developed by
the joint efforts of Baotai Group Co., Ltd., Beijing Central Research Institute
for Nonferrous Metals, Hebei Medical University, Shandong Wendeng Orthopedic
Hospital and the Second Orthopedic Medical Equipment Factory of Tianjin Medical
Instrument Industry Corporation. The results of biological experiments show that
the alloys have good biocompatibility. And can form the good osseointegration
with the bone organization, at present domestic by Shanghai Ai Liai metal
material limited company and so on unit proxy distribution. 2.2 New Beta
Titanium Alloys Since the 1990s, there have been reports about the potential
hazards of V and Al elements to human body in titanium alloy implant materials.
Therefore, the development of advanced biomedical metal materials with excellent
comprehensive mechanical properties and more compatible with human soft and hard
tissues and biomechanics, the new β-titanium alloy, has become the focus of
biomedical metal materials research. A series of new type β titanium alloys were
developed by adding non-toxic elements such as Nb, Ta, Zr,3d titanium wire, Mo
and Sn. 2.3 Ti-Ni alloy. Ti-Ni shape memory alloy is a new type of functional
material. This kind of functional material has peculiar shape memory effect,
superelasticity, fatigue resistance, wear resistance, corrosion resistance and
good biocompatibility. Therefore, the alloy is widely used in the medical field.
The successful application of Ti-Ni shape memory alloy in orthopaedic clinic has
attracted the attention of orthopaedic experts and clinicians, and it is called
"magic metal". The deformation temperature of NTSMA used in orthopedic clinic is
0-5 ℃, and the recovery temperature is 37 ℃. Aft that fracture is fixed by the
NTSMA material, the shape is restore by heating under body temperature or hot
saline wet compress, but the bone restricts the material from restore, so that a
dynamic and continuous pressure or clamping force is generated at the broken end
of the fracture to achieve the effect of fixing the fracture. Expand the full
text 2.4 Porous titanium alloy The surface structure of surgical implants is
closely related to the biological behavior after implantation. Compared with a
compact material, the introduction of the pores remarkably reduces the elastic
modulus of the titanium and the titanium alloy, the strength and the modulus of
the porous titanium can be adjusted to be comprehensively matched by changing
parameters such as porosity, pore diameter and the like, and the open through
hole structure of the porous titanium is fully utilized to promote the adhesion
and ingrowth of bone cells and regeneration and reconstruction of bone tissues
so as to accelerate the healing process, O that the titanium and the titanium
alloy can realize the matching of the material and the elastic modulus of the
bone under the condition of keeping certain strength. At the same time, the
rough surface geometry of porous titanium alloy can promote the growth of new
bone tissue into the pores, which not only strengthens the biological fixation
between the implant and bone, but also enables the stress to be transmitted to
the surrounding bone along the implant.. 2.5 Titanium alloy surface activation
technology The surface activation technology of titanium alloy is one of the key
fields in the research and development of orthopedic implant materials. The
surface of the implant is in direct contact with the human body. Through surface
modification, biocompatibility can be improved and wear can be reduced, thereby
reducing the possibility of implant loosening and ensuring the long-term
performance of the implant.. The composite oxide coating was formed on the
surface of titanium alloy by anodic oxidation, hydrothermal treatment and heat
treatment. The prepared gradient coating has complete crystal form, titanium
bar grade 5 ,titanium seamless
tube, and the surface of the gradient coating has high capability of
inducing a bone hydroxyapatite layer to form and cell adsorption and
proliferation capability, and has good biocompatibility. 2.6 Laser Near-Net
Shaping of Surgical Implants Laser near-net shaping technology is a 3D printing
manufacturing technology, combined with computer control, which gradually uses
high-energy beams to melt titanium alloy powder in the molten pool and process
it into specific shapes of orthopaedic implants or dental restorations.
Northwestern Polytechnical University and other research institutes have done a
lot of research on the laser solid forming process of pure titanium and other
medical metals. The mechanical properties and fatigue properties of pure
titanium implants prepared by this technology are higher than those of pure
titanium, which can meet the requirements of dental implants for mechanical
properties. At present, some progress has been made in the research of
processing titanium-nickel alloy and titanium alloy vascular stents by laser
near-net shaping technology in China. 3. Application of materials for surgical
implants 3.1 Overview of foreign applications Ti-Ni alloys with unique shape
memory properties have been used in stomatology, neurosurgery, cardiovascular
surgery, thoracic surgery, otorhinolaryngology, hepatobiliary surgery, urology
and gynecology since their successful development. Products include dental
orthopedic wire, root canal file, spinal orthopedic rod, bone plate,
intramedullary needle, patella claw, guide wire, guide needle, cardiac patch,
vascular stent, thrombus filter, esophageal stent, respiratory stent, biliary
stent, urethral stent, rectal stent, duodenal stent, external auditory canal
stent, IUD, etc. The hip prosthesis system manufactured by STRYKER Group, one of
the largest orthopaedic professional group companies in the world, uses
Ti-12Mo-6Zr-2Fe alloy, which has reached the highest standard of orthopaedic
clinical requirements in terms of quality, function and clinical effect. At the
same time, the anterior cervical plate system made of Ti-Mo-Zr-Fe alloy has been
used in clinic. At present, these two products have been introduced into the
Chinese market. Titanium alloy precision casting prostheses were developed and
used in clinic in Germany in the 1980s, which promoted the development of modern
functional prostheses. Since then, titanium alloy precision casting prostheses
have been widely used in various countries. Craniomaxillofacial plastic surgery
is widely carried out abroad, especially in Germany, the United States, Japan
and other countries. Plastic surgery brings confidence and happiness to people.
Internal fixation devices used in craniomaxillofacial plastic surgery are mainly
pure titanium plates of various shapes and specifications and pure titanium
screws of various specifications. 3.2 Overview of domestic application Baotai
Group, the largest professional titanium and titanium alloy manufacturer in
China, has been cooperating with other scientific research institutions in the
research and development of titanium bone, titanium stent and other human
implant materials since the 1970s, and has achieved good results. Since the
1970s, China has begun to use domestic titanium and titanium alloy artificial
bones and joints for clinical treatment. The artificial femur and hip joint
produced have good clinical results. In the mid-1980s, the number of domestic
titanium and titanium alloy processing materials used to manufacture human
implants has been increasing. Femoral head, hip joint, knee joint, elbow joint,
shoulder joint and metacarpophalangeal joint made of titanium and titanium alloy
have been transplanted into human body and achieved very good results.
Significant progress has also been made in the development of new beta titanium
alloys for orthopaedic applications and titanium alloys for dental restorations
in China. A variety of medical titanium alloys independently developed by
Shenyang Metal Research Institute, Beijing Nonferrous Metals Research Institute
and Northwest Nonferrous Metals Research Institute have been used in surgical
implants and vascular stents. In the application of porous titanium alloy,
Tangdu Hospital of the Fourth Military Medical University, Northwest Institute
of Nonferrous Metals, Shanghai Jiaotong University and other research institutes
have designed and manufactured porous titanium alloy implants, which have been
widely used in clinic and achieved good results. 4. Conclusion The defect of
human hard tissue caused by the aging of population has become a major problem
worldwide. China has a large population, the aging problem is very serious, and
there are many patients who need rehabilitation surgery with the help of medical
implant materials. According to statistics, in the past 30 years, the market of
surgical implants in China has developed at an alarming rate. The average growth
rate in the past 10 years has been maintained between 15% and 30%, and is
expected to continue to grow at a rate of more than 10% in the next 10 years. It
can be seen that the market prospect of titanium alloy implants in China is very
broad. Although China has done a lot of research work in the research and
application of titanium alloy materials for surgical implants and made
remarkable progress, compared with developed countries such as Europe, the
United States and Japan, there is a big gap in the design, manufacture,
processing, equipm ent, surface treatment and technological level of titanium
alloy implants. The implants produced in China are difficult to meet the market
demand, and most of the high-end implants need to be imported from abroad,titanium
sheet grade 5, which has brought unprecedented opportunities and challenges
to medical material research units, material manufacturers, medical research
institutions and clinical medical experts in China. These units should
strengthen cooperation and work hard to achieve the localization of high-end
implants for the benefit of the people. To promote the healthy and stable
development of China's medical titanium alloy industry. Return to Sohu to see
more Responsible Editor:. yunchtitanium.com