Current status of robot‐assisted surgery in the clinical application of trauma orthopedics in China: A systematic review

Abstract Background and Aims To elaborate on the development and characteristics of trauma orthopedic robots and their real curative effect in a clinical application through the collection and analysis of relevant literature and reported clinical results. Method We conducted the Embase, ScienceDirect, Pubmed, Medline, Wanfang, CNKI, and VIP search of the literature on robotic‐assisted surgery in trauma orthopedics in China. We combined search terms with “robotic surgery/artificial intelligence surgery/navigation surgery,” “trauma/trauma orthopedics,” and “China/Chinese.” The exclusion criteria were: (1) articles in languages other than English or Chinese, (2) articles focused on other topics other than robotic‐assisted surgery in trauma orthopedics of China, (3) article types were not clinical studies (reviews, basic research, etc.), and (4) articles were not included in the Chinese core journals or science citation index. Authors, type of surgery, robot type, and clinical research results were recorded and analyzed. Results There were three categories of surgical robots in the clinical application of trauma orthopedics (TiRobot, electromagnetic navigation surgical robots, and small medical robots developed by Beijing Jishuitan Hospital). In terms of blood loss, the fluoroscopy time, and fluoroscopy frequency, most studies found that the robot group was significantly better than the traditional group. Conclusions Robot‐assisted surgery has obvious advantages in accuracy, stability, and reducing intraoperative radiation exposure, but there is no final conclusion about functional recovery.


| INTRODUCTION
The clinical application of robot-assisted surgery has become possible with the improvement of robot technology (computer control technology, detection technology, image processing technology, multimedia and information network technology, man-machine interface technology, and mechanical and electronic technology) and the rapid development of minimally invasive surgery. 1 As early as the 1980s, surgical robots came into being. In 1985, robots were first used in brain surgery. 2 Because of the advantages of good stability, flexible operation, and accurate movement, surgical robots were more and more used in clinical treatment. In 1992, the first robot system (Robodoc) in the world was applied to hip replacement surgery, creating a precedent for the application of surgical robots in orthopedics. 3,4 In recent years, the types of orthopedic surgical robots were becoming more and more complete, and the application scope and scene were also gradually expanding. The robot systems such as Robodoc (Curexo Technology Company), SpineAssist (Mazor Robotic Company), Stryker-Nav (Stryker Corporation), and Renaissance (Mazor Robotic Company) had developed rapidly and had been successfully used in hip and knee arthroplasty, pedicle screw placement, and other operations. 5,6 Compared with joint surgery and spine surgery, there were few surgical robots used in trauma orthopedics. 7 However, this situation had changed because of the rapid development of image processing technology and the improvement of navigation tracers in recent years. 8 Surgical robot was reported to be applied to the precise positioning and nail placement in orthopedic trauma surgery to improve surgical accuracy and reduce surgical injury. 7 Especially in China, the application research of computer-assisted navigation surgery and medical robots in trauma orthopedics was funded by national scientific research projects in 2001. After that, research reports on the clinical application of robots in trauma orthopedics appeared one after another. 9

| METHODS
This systematic review was conducted in accordance with the preferred reporting items for systematic reviews guidelines.

| Search strategy
Publications related to robotic-assisted surgery in trauma orthopedics in China were identified through a computerized literature search.
We conducted an Embase, ScienceDirect, Pubmed, Medline, Wanfang, CNKI, and VIP search of the literature on roboticassisted surgery in trauma orthopedics in China. We combined search terms with "robotic surgery/artificial intelligence surgery/ navigation surgery," "trauma/trauma orthopedics," and "China/ Chinese." All electronic searches were conducted within a day of March 7, 2022, to avoid changes in citation rates as much as possible.

| Data extraction
Two authors (Jingwei Xiao and Hongbao Wu) independently extracted data with a structured data collection form. Discrepancies were resolved by discussion with the senior investigator (Jianming Chen). The following information was sought from each article: (1) authors (first author), (2) publication year, (3) type of disease, (4) type of surgery, (5) robot type, (6) published journal, and (7) clinical research results (follow-up time, blood loss, operating time, fluoroscopy frequency, functional score, internal fixation placement, fracture healing, etc.). The level of evidence for clinical studies was also determined by an assessment based on the level of evidence from the Oxford Centre for Evidence-Based Medicine (OCEBM). 10 There was 100% agreement between the two authors about the level of evidence.

| Evaluating the included studies
Based on included study design, research setting, and goals, the selected articles were all clinical studies, mainly divided into case reports, case series, retrospective cohort studies, prospective cohort studies, and randomized control trials (RCTs).

| Methodological quality assessment
Levels of evidence were assessed using the OCEBM framework. The quality of clinical studies was independently assessed by two authors (Jingwei Xiao and Hongbao Wu) using the methodological index for non-randomized studies tool. 11 The randomized controlled trials were scored using the revised Cochrane risk-of-bias tool (RoB 2). 12 The risk of bias in the following seven areas was assessed as "low," "high," or "unclear": sequence generation; allocation concealment; whether the participants, personnel, and results were evaluated by blind method; incomplete outcome data; selective reporting; and other sources of bias (if needed).

| Analysis
A data collection table in Microsoft Excel was designed by one author (Weigang Lou) to display the information extracted from each eligible study. Owing to heterogeneity in study design, participants, interventions, and outcome measures, a quantitative meta-analysis was not appropriate.   There were five types of clinical studies. Among them, the most type was a retrospective cohort study, with a total of 18 articles. The second was the case series (n = 17). The rest were prospective controlled studies, RCTs, and case reports.

| Study characteristics
Our research showed that 84.6% of the included articles used this type of robot, which was the main model of trauma orthopedic robot undoubtedly.

| Operating time
Because of the different operation sites, the operation duration was different. Among the 20 cohort studies, 10 retrospective cohort studies showed that the robot operation time was significantly shorter than that of the traditional group, which was statistically significant. However, five retrospective cohort studies showed no significant difference between the two groups, including a study comparing robots with O-arm navigation. 13 Three retrospective cohort studies did not involve the study of operation time (Table 2). It was important to note that both an RCT study and a prospective cohort study showed no significant difference between the two groups regarding the operating time. 14,15

| Blood loss
A total of 23 articles mentioned intraoperative blood loss. All cohort studies (11 articles) showed that the blood loss in the robot group was significantly less than that in the traditional group, which was statistically significant. The 11 cohort studies included 10 retrospective cohort studies and 1 prospective cohort study (Table 2).

| Fluoroscopy frequency
The study of fluoroscopy frequency was mentioned in 21 articles. One retrospective cohort study showed that there was no significant difference in fluoroscopy frequency between the robot group and the traditional group. 16  Twelve of them were cohort studies. Only 1 of the 12 articles considered that there was a statistical difference in fracture healing between the robot group and the traditional group. 17 However, the robot group in this study performed bone for pelvic fractures, so the results will be disturbed by the bone grafting operation.

| DISCUSSION
Orthopedic precision treatment technology has become one of the main development directions of surgery in the 21st century. 18 In particular, the surgical robot as the representative of this technology has become a research hotspot in the field of medicine and robot. 19 The surgical robot can achieve accurate spatial positioning and stable path navigation, which greatly increases the safety of surgery and reduces the risk and the trauma of surgery. 20  increased year by year and reached a new peak in 2019. This shows that the research in this field has attracted more and more researchers' attention. Trauma orthopedic robots involved as many as eight kinds of surgery with the increase in application year by year, but the application was mainly focused on the pelvic injury. This was closely related to the complex anatomical structure of the pelvis and the high risk of manual operation. 21 Especially in the implantation of sacroiliac screw, LC-II screw, and acetabular anterior and posterior column screw, the "opportunity tunnel" of pelvic fixation was narrow and multiplanar imaging was required to avoid damaging the nearby fragile nerve and vascular structures. Therefore, robots were favored by surgeons because of their precision and minimally invasive characteristics. 22 This study found that up to 29 articles reported the operation of cannulated screw placement, which also confirmed this phenomenon. At present, there are three kinds of trauma orthopedic robots involved, and the most widely used is "Tianji" As for the clinical application effect of trauma orthopedic robots, our research mainly analyzed the outcomes of clinical articles belonging to a cohort study. Wang et al. 24 and Luo et al. 25 found that the operation time of the trauma orthopedic robot group was significantly less than that of the traditional group. A total of 10 cohort studies had similar views.
However, there were also five cohort studies. Two of them were prospective cohort studies and RCT studies with a high level of evidence. 14, 15 Duan et al. 15 believed that the total operation duration included the noninvasive period of robot path planning and the invasive period of actual operation. In fact, the operation time from the insertion of the first guide needle to skin closure was very short, which was significantly less than that in the traditional group. At the same time, the operator's operation speed was relatively fast, so most of the time was spent on equipment placement and debugging, image acquisition, and other noninvasive procedures. 15 This was also the main problem of the trauma orthopedic robot at this stage. The preparation time in the early stage of the operation was too long, which affected the completion speed of the whole operation. Wang et al. 14 also believed that even if there was little difference in operation time between the two groups, it was an acceptable amount of time for new technology. In addition, the implantation time of the guide needle in the robot-assisted group was significantly shorter than that in the traditional group, because the number of attempts to insert the guide needle in the robot-assisted group decreased, and the stable and accurate operation increased. In terms of surgical blood loss, all cohort studies involved believed that the robot group was significantly less than the traditional group, which was closely related to the high precision of the robot and the high success rate of single nail placement. 26 Similarly, most cohort studies believed that the robot group was significantly reduced in terms of fluoroscopy frequency and fluoroscopy time, which was statistically significant. Only the research of Zhu et al. 16 found no difference between the two groups. They believed that this was related to the need for additional surgical steps for robotic surgery. In the early days when the system was first introduced, surgeons were not skilled enough. The frequency of intraoperative fluoroscopy was mainly related to the need for repeated confirmation during the placement of the guide needle and cannulated screw, and the TiRobot system also could not help control the insertion depth. Therefore, there was no difference in the above data between the two groups. With the improvement of technology, we hope that the trauma orthopedic robot can make a breakthrough in controlling the preparation time and automatically controlling the insertion depth. In terms of functional score, eight articles believed that there was a statistical difference in functional score between the robot group and the traditional group. However, seven articles believed that there was no statistical difference between the two groups. Therefore, whether the robot group is better than the traditional group in the functional score is still uncertain, which needs to be determined by future research. In terms of bone healing, most studies had found that the robot group was not significantly better than the traditional group.

| Study limitation
This study is the first systematic review of the clinical application of trauma orthopedic robotic surgery in China. Especially for foreign scholars, there was little information about trauma orthopedic robots in English, which was well supplemented by the results of this study.
Limitations: 1. The evidence level of the articles included in the study was low, most of which were III-IV. The lack of high-level studies such as RCT had a certain impact on the results. 2. Some of the F I G U R E 2 TiRobot included articles included Chinese literature, which was inconvenient for scholars from non-Chinese countries to further explore ( Figure 2).

| CONCLUSION
Robot-assisted surgery in the clinical application of trauma orthopedics in China is experiencing rapid development. Compared with traditional surgical methods, it has obvious advantages in accuracy, stability, and reducing intraoperative radiation exposure, but there is no final conclusion about functional recovery.

CONFLICT OF INTEREST
The authors declare no conflict of interest.

DATA AVAILABILITY STATEMENT
The data that support the findings of this study are available from the corresponding author upon reasonable request. Ding Xu had full access to all of the data in this study and takes complete responsibility for the integrity of the data and the accuracy of the data analysis.

ETHICS STATEMENT
None required.

TRANSPARENCY STATEMENT
The corresponding author Ding Xu affirms that this manuscript is an honest, accurate, and transparent account of the study being reported; that no important aspects of the study have been omitted; and that any discrepancies from the study as planned (and, if relevant, registered) have been explained.