3D printing customized prostheses have been widely used in orthopedic clinical practice, such as 3D printing artificial acetabular prostheses, scapular prostheses, pelvic prostheses, thoracolumbar artificial vertebral bodies, and personalized prostheses. 3D printing of various shapes of internal plants has also helped doctors solve difficult and severe treatment problems such as spinal tumors and severe trauma.
Recently, a patient underwent a vertebral body replacement operation at the orthopaedic clinic of Peking University's Third Hospital, and was implanted with a pure domestic "self stable" 3D printed titanium alloy microporous structure artificial vertebral body.
It is understood that the basic material of the artificial vertebral body is titanium alloy powder, which is made in China. The 3D printing equipment for producing the vertebral body is also independently developed in China. The implantation of this "self stable" 3D printed titanium alloy microporous structure artificial vertebral body marks that in the field of orthopedic applications of 3D printing technology, China not only has the ability to independently design and develop relevant innovative products, but also has the ability to produce with domestic equipment and materials, realizing the entire process of innovation from original design to product development and manufacturing.
Open up the road of 3D printing bone localization
Vertebral replacement is used in patients with cervical spondylosis, cervical tumors, and other types of patients who need to have their vertebral bodies removed for treatment.
At present, the repair technology of cervical vertebra resection in China generally adopts the method of titanium mesh plus titanium plate and screw, that is, after the vertebral body is excised, a cylindrical titanium mesh structure is placed in the bone defect area after the vertebral body is excised, and a titanium plate is placed in front of the titanium mesh, with the upper and lower ends of the titanium plate fixed to the adjacent vertebral body with screws.
Due to the need for combination of devices, the fixation strength is reduced. At the same time, a titanium plate that serves as a fixation is covered at the front and rear ends of the surgical vertebral body, while the anterior portion of the cervical spine is the esophagus, and the protruding portion of the titanium plate is prone to causing compression to the esophagus.
"The 'self stable' 3D printing titanium alloy microporous structure artificial vertebral body has been improved on this issue, removing the titanium plate that causes a pressing sensation to the patient, and directly combining the screw and vertebral body. The implant is flush with the surface of the cervical vertebra, achieving a 'zero notch'.
”As the surgeon for the above-mentioned patient with "self stable" 3D printed titanium alloy microporous structure artificial vertebral body, Liu Zhongjun, director of the Institute of Spinal Surgery, Peking University Third Hospital, professor of orthopedics, and chief physician, and expert group leader of the centralized unit of medical additive manufacturing technology and medical device standardization technology, pointed to the artificial vertebral body model and said, Previous studies have confirmed that the biomechanical properties of the "self stable" 3D printed titanium alloy microporous structure artificial vertebral body are better than the previously used titanium fillers, and make the surgery more concise.
He introduced that this "self stable" 3D printing titanium alloy microporous structure artificial vertebral body has been on the market for more than one year in China, and medical units have received good feedback on its use. It will gradually be introduced to the international market in the future.
3D printing, also known as additive manufacturing technology, is a revolutionary breakthrough in manufacturing technology. In recent years, this technology from the industrial field has also made significant contributions in the medical field – making medical models, assistive devices, prostheses, surgical guidance devices, and so on. Of course, there are also 3D printed bones.
"Currently, titanium alloys are mostly used as orthopedic internal fixators for 3D printing. Titanium alloys are also one of the most commonly used metal materials for 3D printing. Titanium alloys have good compatibility with human tissues and do not exhibit immune rejection such as allergies.".
"In recent years, the application of titanium alloys in the field of orthopedics has become very mature." Introduction by Liu Zhongjun. At the same time, he said, titanium alloy vertebral bodies can also be designed with microporous structures that resemble sponges, so that bone cells from adjacent normal vertebral bodies can grow into them, ultimately achieving fusion, greatly enhancing robustness. "This is a very important performance in the medical field," he said.
Before 3D printing technology was applied to orthopedics, scientific and technological workers also conducted research on the design, application, and transformation of personalized bone and joint prostheses. However, traditional standardized prostheses cannot be reconstructed or have poor results, and the difficulty of design and long manufacturing time seriously limit their clinical application.
"However, 3D printing can customize the complex human bones needed by patients, providing an opportunity for the transformation of the treatment mode of orthopedic surgery from 'cutting feet to fit shoes' to' tailoring to measure ', achieving a true sense of' personalized 'and' precision 'treatment." Liu Zhongjun said.
Currently, 3D printing customized prostheses have been widely used in orthopedic clinical practice, such as 3D printing artificial acetabular prostheses, scapular prostheses, pelvic prostheses, thoracolumbar artificial vertebral bodies, and personalized prostheses. 3D printing of various shapes of internal plants has also helped doctors solve difficult and severe treatment problems such as spinal tumors and severe trauma.
Currently, multiple research and development teams in China are exploring the use of magnesium metal for 3D printing of human internal plants. "Magnesium alloy has excellent performance in repairing and reconstructing bone structure and function, and it also has certain anti infection ability, which can reduce related infection complications."
This is a direction of innovation in 3D printing orthopedic application materials in the future.
Can we design a better 3D printing implant that combines faster with the patient's bone tissue and shortens the disease treatment cycle?
Can growth promoting drugs be attached to the surface of inner plants to make bones grow faster?
Can sustained-release drugs be placed in inner plant pores to treat diseases while playing a supportive role?
These are issues worthy of further consideration and research by scientific and technological workers.