[Interview] Associate Professor Zhong Da, Xiangya Hospital of Central South University: 3D printing guide plate achieves 100% surgical success rate

  3D Printing models, guides, implants, and then to biological tissues. Many beautiful fantasies about the application of 3D printing in medical treatment have long been modified by chattering words on the Internet to become taller and unpredictable. How to make this The implementation of this technology, so that patients can really benefit from it? Associate Professor Zhong Da of Xiangya Hospital of Central South University focuses on applying 3D printing to his professional field- adult DDH (congenital dysplasia of the hip) hip replacement surgery . After continuous in-depth research, in the past year or so, with the help of Hunan Huashu High-Tech Technology Co., Ltd. (hereinafter referred to as “Huashu Hi-Tech”) 3D printing solutions, 3D printed hip joint preoperative model and 3D printed hip joint The combination of osteotomy guide plates has successfully performed more than 40 such operations, which has made the success rate of hip replacement surgery, which is highly dependent on the clinical experience of doctors , 100% , and the accuracy of the surgery has been greatly improved, making it unique in the industry.

“The application of 3D printing in medical treatment is a vast blue ocean. Even if there are ten academician-level professors, it is difficult to exhaust the mystery.” With the increase in clinical cases, Zhong Da also feels more and more deeply about the benefits of 3D printing. The charm lies. Break the old concept and embrace the new technology3D printing was born in response to the needs of the industry. In recent years, it has not intended to become popular in the medical industry. As a well-known expert in the orthopedics circle, in the middle of 2015, Associate Professor Zhong Da was not optimistic about this technology when he first came into contact with the concept of 3D printing. For high-end and complex surgery, I thought it would take a long time to routinely apply it,” Zhong Da recalled. Printing a simple preoperative reference model seemed even more redundant for orthopedic surgeons with solid basic skills. Experts of the older generation have their own stubbornness in technology. They have accumulated a deep foundation. They can infer many details through the shading performance of X-ray films and the tomography of CT scans. The family members of patients and those who do not know how to do it, let alone rely on 3D printed models for surgery. “Later I slowly discovered that I can’t say that their concept is wrong, it’s actually not the case.” At the end of 2015, a relatively failed operation made Zhong Da start to rethink: First of all, even if he has done so many operations, his clinical experience is enough. Enrichment can not avoid mistakes; secondly, it takes a long time to reach their level to train doctors only relying on the experience of the older generation. With the help of this kind of three-dimensional digital imaging, the training time can be greatly shortened; More importantly, if there is a tool that can lower the threshold of surgery, so that the majority of grassroots doctors can also carry out difficult operations, without the need to concentrate patients in large hospitals, it can better benefit the people. As a result, Zhong Da’s view of 3D printing has changed, and he began to conduct applied research with the support of the director of Orthopedics Hu Yixun. And why he loves 3D printing guides, Zhong Da joked that he had picked up the “leak”. He analyzed that the predecessors represented by Academician Dai Kerong have accumulated rich experience in 3D printing implant materials. Exquisite, it can’t make myself better in the actual operation. However, the guide plate is a “neutral position” that others have not studied in depth. It does not have such high requirements for technology and materials, and can rely on the existing partners of Xiangya Hospital-Huashu Hi-Tech and Hunan Huaxiang for incremental manufacturing Co., Ltd. (hereinafter referred to as “Hunan Huaxiang”) provides technical support. “Even if Academician Dai has finished the 3D printed implant, it needs the assistance of guide plates and guides to install it in an accurate position,” said Zhong Da.

After referring to foreign experience, Zhong Da led the Xiangya orthopedics team to develop his own system and completed the first hip replacement surgery assisted by a 3D printed guide plate in March 2016. Today, after several generations of improvements, there have been more than 40 successful surgical cases. The Xiangya Orthopedics team applied for a national invention patent for this technology and obtained a related national utility model patent authorization. With the superb professional level and experience accumulation of this technology, Associate Professor Zhong Da also won the 2016 “Golden Hand Award” Orthopedic Surgery First place in the National Finals of the Case Invitational. The use of 3D printed guides for hip replacement surgery is not Zhong Da’s first creation. Why does the Xiangya orthopedics team alone have such a big impact in China? Zhong Da said that some teachers in Anhui and Xinjiang also made hip joint guides, but they all gave up. Investigating the reasons, he analyzed: First of all, the hip joints are relatively high in fault tolerance, and the position of the hip joints does not seem to be very It’s important, they think that the 3D printed pointing device is not of great significance; secondly, because there is no good way to point, the structure in the hip joint is very complex, there are many cartilage tissues, these cartilage tissues cannot be seen on CT Therefore, how to avoid these organizations as much as possible to obtain accurate data and find accurate positioning and orientation is more difficult. “I think their guide design is based on the acetabular fossa to obtain data, but there is a lot of cartilage in the acetabular fossa, which will affect the accuracy of the data, and ours is based on the bone of the upper outer edge of the acetabulum. The quality of these bones is the basic point. These bones are very clean and clear, and can be used as a good source of data to achieve precise positioning and orientation. The additional trauma for this is not large and is completely acceptable clinically.” Zhong Da explained.

Zhong Da has done a lot of research work on how to find a better angle of the upper edge of the acetabulum, which point and which surface is more suitable as a data source, and this is the key reason for the team’s success. Academician Dai Kerong of the Chinese Academy of Engineering also spoke highly of Hunan’s 3D printing medical application results in a media interview: “All provinces are doing 3D (printing), and Hunan is doing better.” In addition, due to the new technology, the surgeon’s life can be greatly reduced. Training time has become a shortcut for young doctors to grow up. Therefore, the support of enlightened department leaders and senior experts is crucial. It can be said that “without the support and guidance of Professor Hu Yiheng, the director of orthopedics, there would be no new technology success!” Associate Professor Zhong Da said affectionately. Accurate routine surgery, routine special surgery“Regular surgery can be satisfied with conventional instruments, but 3D printing must ultimately serve specialized surgery.” Developmental dysplasia of the hip (DDH) has about tens of thousands of cases nationwide each year. In Xiangya Hospital, the top domestic hospital, there are about dozens of surgeries each year. This number is not too much. Do surgical cases that can meet demand with traditional methods really need 3D printing? In this regard, Zhong Da believes that “conventional surgery and special surgery are not static. When you have high requirements for surgical accuracy, conventional surgery can also become special surgery. If you can use simple tools to accurately position, special surgery It can also be routine.” In hip replacement surgery, 3D printed guides can help doctors quickly determine the location of the acetabulum, the size, depth, and angle of the acetabulum, and the position, angle, and length of the acetabular screw during the operation. , Which makes the accuracy of implanted prostheses differ by only one or two millimeters, reduces surgical damage, shortens the operation time, and improves the success rate of complex artificial hip replacements. Not only that, but 3D printing is also a useful tool for doctors. It prevents doctors from being exposed to X-ray sources for a long time and protects their health. With the continuous progress of society, patients will have higher and higher requirements for surgery, and more and more so-called conventional operations will enter special categories, so the application of 3D printing technology will become wider and wider.

“In the past, I thought it was meaningless to make a model, and the guide plate was just a small gap, but as I used more and more applications, I found that 3D printing is actually a blue ocean. Like Academician Dai, who has been working in this field for many years, it is still not exhausted. The mystery is that it involves materials, orientation, various clinical applications, etc. There are too many contents that can be developed,” Zhong Da lamented. But at present, medical 3D printing also has a comprehensive talent gap problem., Zhong Da summarized the four key talents of medical 3D printing: clinicians who provide ideas and inspiration; 3D printing composition designers; mechanics engineers; clinical imaging professionals. 3D printing is a comprehensive subject, and whether the final printed product can be used is determined by many factors. “Huashu Hi-Tech’s 3D printing technology is very high, just like they have a Heavenly Sword and Dragon Slaying Knife, but where this sword will fall, it may require the guidance of a doctor.”

At present, the working model of Xiangya Orthopedics team and Hunan Huaxiang is based on doctors as the core, doctors put forward ideas, and then drawings by Hunan Huaxiang engineers, using Huashu Hi-Tech 3D printing solutions to make them, and then return to the clinic. Through the doctor’s inspection, after repeated cartographic inspections, finally reached the point of harmony. “There are still many difficulties. Although these engineers have beautiful drawings, they do not understand mechanics. It is still a big problem that the things they design can not withstand the test of mechanics,” Zhong Da mentioned, “In addition, the source How to better process the CT data in the hospital? Some CT values ​​have high signals and some have low signals, and how can they be accurately restored? At present, these are preliminary processed by engineers who do 3D printing, but the results are satisfactory. The degree is often not enough.” Zhong Da gave another example, if one day we can combine CT and MRI to show bone tissue and soft tissue at the same time, we can better distinguish soft and hard tissues and make the image more accurate, but this A professional imaging expert is needed to do it, and these talents are currently in short supply in China. Combined with other technologies, the blue ocean of 3D printing is bluerAt present, there are two extreme attitudes towards 3D printing. One thinks that 3D printing is completely useless and rejects it, while the other thinks that only 3D printing technology is good, and other technologies are not good. From the standpoint of Zhong Da as a doctor, as long as the useful technology is good, 3D printing can quickly produce special-shaped guide plates. This is an advantage that other technologies can’t compare, but 3D printing can never replace the previous one. “3D printing must be combined with new and old technologies to achieve greater benefits”, and this is the direction that the orthopedics team of Xiangya University is working hard. Even though 3D printed guide plates can make doctors even more powerful in hip replacement surgery, Zhong Da also knows that there are still some problems with it. For example, this guide is used as a tool, but it occupies a certain amount of space during the operation. Now, after several generations of design improvements, the orthopedics team at Xiangya Hospital has figured out ways to miniaturize it, and install it to those that are not used in the operation. Location, so as to achieve the purpose of saving space. Following this line of thinking, Zhong Da put forward a new idea. He hopes to combine 3D printing technology with laser guidance.

“Use laser to point and position, so that there is no need to consider the size of the tool.” In addition, with the rapid development of AR (augmented reality) technology in recent years, Zhong Da believes that 3D printing + AR can be used in doctors’ clinical operations. Play a huge role in theAR technology allows the doctor to see the real surgery scene through a pair of glasses, and at the same time project a virtual lesion on the doctor’s retina, showing the nerves and blood vessels in the bone tissue clearly in front of the doctor’s eyes to communicate the virtual And reality achieves the purpose of helping the operation. This year, Weihai Central Hospital successfully completed a huge fusiform tumor of the tail of the sacrum and vertebral body replacement through AR technology. The application of AR technology to orthopedics is the first case in the country. However, Zhong Da told us that this technology still has many limitations, among which data matching is a difficult problem. Using AR technology, the doctor first needs to scan the appearance of the patient’s lesion to obtain data. During the operation, the data entered in advance in the glasses will automatically match the lesion, thereby presenting a virtual scene in front of the doctor’s eyes. But in fact, there is no way to strip the patient’s bones for the doctor to scan, so 3D printing can play its role. Accurately matching the data can be achieved by aligning several points of the bone by 3D printing, and then scanning the 3D printed parts. “In the future, we may consider research in this area,” said Zhong Da. 3D printing is a very deep and big blue ocean, and to find one’s own world in this blue ocean, and can really benefit the people, Zhong Da’s suggestion is to find the most distinctive and most development direction One point of the in-depth study, “We are not to compare how many things we have made, but to make things that are better than others.” So far, Huashu Hi-Tech and Hunan Huaxiang have expanded 3D printing to more than 20 tertiary hospitals across the country, achieved business coverage of 16 clinical departments, and accumulated more than 1,500 clinical application cases of 3D printing. The disciplines involved include orthopedics, Hepatobiliary, urinary, tumor, extrahematology, surgery, oral cavity, plastic surgery, rehabilitation and other 16 departments are used. The breadth, depth and number of cases of its subject application ranks first in the country, and there is no case of patient disputes. It is called by experts ” Visible precision treatment”. Based on this premise, the team of Associate Professor Zhong Da of the Department of Orthopedics of Xiangya Hospital started with a small 3D printed hip joint guide, and really pulled 3D printing from the cloud to the front of the doctor’s operating table, making this tall technology Lovely and approachable, it reflects the humanistic care for the people.