The efficacy of “TiRobot”orthopaedic robot-assisted VS conventional fluoroscopic percutaneous screw fixation of the sacroiliac joint
Authors: Li Ningtao , Zhu Zongdong , Xiao Chengwei , Wei Dan , Wang Fei , Zhang Wei , Hu Jiang 
Published: December 2022

Abstract
Purpose
This study is to compare the precision and safety of the orthopaedic robot with conventional fluoroscopy for assisted percutaneous sacroiliac joint screw implantation.

Methods
Retrospective analysis was performed on the clinical data of 57 patients with unstable posterior pelvic ring injuries who were admitted and met the criteria between January 2017 and January 2022. All of these patients underwent percutaneous sacroiliac joint screw implantation, and their clinical data were split into two groups based on the surgical technique: a RA group (robot-assisted implantation, 30 patients, 54 screws) and a CF group (conventional fluoroscopic freehand implantation, 27 patients, 42 screws). There were 96 screws placed in total. The durations of the two groups’ operations, fluoroscopy examinations, fluoroscopy doses, total number of fluoroscopies, and intra-operative guide pin applications were noted and compared. On post-operative CT scans, the placement of each screw was assessed using the Gertzbein-Robbins classification. Finally, imaging Matta criteria were used to assess the sacroiliac joint fracture reduction. The Majeed functional score was used to assess clinical function.

Results
Both groups successfully completed 57 procedures in total. In both groups, there were no consequences from vascular injury, wound infection, or urinary tract infection. Additionally, there were no complications from robotic-induced nerve injury, operating time, fluoroscopic dose, and the frequency of fluoroscopic; the number of percutaneous punctures in the RA group was lower than that of the CF group.There were statistically significant differences between the aforementioned data (P < 0.05). The modified Matta evaluated the effectiveness of fracture reduction. In the RA group, there was no statistically significant difference between the CF group (P > 0.05). According to the modified Gertzbein-Robbins classification criteria, the 54 screws implanted in the RA group were classified as follows: class A (45), class B (5), class C (4), and class D (0); the accuracy rate of the implants was 92.59%. Forty-two screws implanted in the CF group, 30 screws were defined class A, class B (3), class C (7), and class D (2). The accuracy rate of the implants was 78.57%(χ2 = 3.967, P < 0.05). There was a statistically significant difference between the two groups. The Majeed score 30 patients in RA group, one month post-operation, 16 considered exceptional, eight decent, six moderate, and zero bad. Post-operation more than six months,25 recorded exceptional, five decent. By the time,27 patients in CF group,12 exceptional grade, eight decent, six moderate, and one bad,one month post-operation. Post-operation more than six months,22 recorded exceptional, five decent.Both group (P > 0.05).

Conclusion
“TiRobot” robot-assisted screw implant treatment for unstable posterior pelvic ring injury has a greater success rate than traditional surgery as compared to conventional percutaneous screw implant. It is a precise, secure, and minimally invasive surgical technique that can also be applied to severe pelvic injuries even congenital sacral deformities.