Abstract: Objective  To discuss the early efficacy of Rossum Robot combined with TiRobot in the treatment of unstable pelvic fractures, thereby analyzing its clinical advantages and limitations. Methods  A retrospective evaluation of 19 patients with unstable pelvic fractures treated with Rossum Robot combined with TiRobot at the Department of Orthopedic Trauma,  Foshan Hospital of Traditional Chinese Medicine between May 2022 and November 2023 was conducted. The cohort included 10 males and 9 females according to the Tile classification, there were 14 type C and 5 type B fractures.The median interval from injury to surgery was 12(6-34)d. Minimally invasive closed reduction and internal fixation of pelvic fracture was completed with the joint intervention of the Rossum Robot and TiRobot. Pelvic computed tomography (CT) scans and anteroposterior, outlet, and inlet X-rays were taken before and after surgery. The maximum residual displacement of pelvic rings after reduction were measured according to X-ray and CT images, and the quality of fracture reduction was evaluated by Matta criteria.The fluoroscopy frequency, fluoroscopy time, surgery time, intraoperative blood loss, number of intraoperative guide pin adjustments, quantity and quality of inserted screws, and maximum residual displacement of pelvic rings after reduction were documented.The screw positions were graded according to the postoperative three-dimensional CT reconstruction images.The postoperative monitoring period, fracture healing time and postoperative complications incidence  were recorded, and the Majeed scoring system was used for functional evaluation. Results  With the joint intervention of the Rossum Robot and TiRobot, all 19 patients successfully completed minimally invasive closed reduction and internal fixation of pelvic fractures.The median intraoperative fluoroscopy frequency was 28 （10-120)times. The median fluoroscopy time was 25.2 (6.0-72.6)s. The median surgery time was 206 (125-231)min.The median intraoperative blood loss was 100(50-400)mL. During the surgery, the guide pin adjustment was performed a total of 4 times among 19 patients, with an average of 0.21 adjustments per patient.A total of 67 screws were inserted, with 65 screws being of excellent quality, 0 screws  good quality, and 2 screws poor quality. The overall excellent and good rate for the screws' placement quality was 97.01%.The maximum residual displacement after reduction of pelvic ring was (6.59±3.68) (1.21-13.00)mm.According to Matta criteria, the reduction quality of the pelvic ring was excellent in 7 cases, good in 9 cases, and fair in 3 cases, with a good-to-excellent rate of 84.21%.Follow-up for the 18 cases lasted for 17 months (6-21)months, with the Majeed functional score averaging （86.00±6.65） (74.00-98.00)points and a good-to-excellent rate of 100%, with 8 cases scored excellent, and 10 good. Conclusions   In our study, the Rossum Robot combined with TiRobot can complete intelligent, safe, accurate, minimally invasive, and homogeneous closed reduction and internal fixation for most patients with unstable pelvic fractures, and it can achieve good early efficacy.

Key words: pelvic fractures, three-dimensional navigation, elastic traction, fracture reduction, fracture internal fixation surgery, robot-assisted surgery