Objective:To investigate the clinical efficacy of robot-assisted screw fixation for unstable pelvic ring multifocal fractures.Methods:A retrospective analysis was performed on 76 patients with unstable pelvic fractures treated with orthopaedic robot-assisted screw fixation in the Trauma Center of the Affiliated Central Hospital of Shandong First Medical University from January 2015 to June 2022, including 43 males and 33 females, aged 52.53±13.68 years (range, 16-87 years). There were 43 cases of falling injuries from high places, 22 cases of traffic accidents, 11 cases of crushing injuries and heavy objects. Fifty-five patients were employed before the injury, while 21 were not. Fractures were classified according to the Tile classification, with 72 cases classified as type B and 4 cases as type C. Robot-assisted fixation techniques included internal fixator (INFIX), anterior ring screws, sacroiliac screws, and LC-II screws. Intraoperative blood loss, fluoroscopy frequency, surgical time, and the success rate of initial guidewire placement were recorded. Fracture reduction quality was evaluated using the Matta criteria, and postoperative pelvic function recovery was assessed using the Majeed criteria.Results:A total of 150 surgical procedures were performed on 76 patients, including 34 cases of INFIX fixation, 48 cases of anterior ring screws, 61 cases of sacroiliac joint screws, and 7 cases of LC-II screws. The mean intraoperative fluoroscopy frequency was 46.63±17.50 times (range, 15-93 times). Intraoperative fluoroscopy frequency varied among different fixation techniques, with INFIX group at 16.44±4.32 times, LC-II group at 21.59±5.80 times, anterior ring screws group at 29.44±11.65 times, and sacroiliac screws group at 23.10±11.87 times. The intraoperative blood loss was 20 (10, 47.5) ml (range, 5-300 ml), and the surgical time was 105 (86, 150) min (range, 30-290 min). The mean surgical time varied among different fixation techniques. All patients were followed up for an average of 6.46±2.26 months (range, 3-16 months). Clinical healing was achieved in all patients within 6 months, with an average time of 3.14±0.50 months. At the last follow-up, fracture reduction quality assessed by the Matta score was excellent in 21 cases and good in 43 cases, with an excellent/good rate of 84% (64/76). The Majeed score was 81.82±9.14 points (range, 50-92 points). For patients who were employed before the injury, the Majeed score was 86.55±4.85 points (range, 60-92 points), with 49 cases rated as excellent, 5 cases as good, and 1 case as fair. For patients who were not employed before the injury, the Majeed score was 69.43±5.34 points (range, 50-73 points), with 18 cases rated as excellent, 2 cases as good, and 1 case as fair. The overall excellent and good rate was 97% (74/76). Among patients who underwent INFIX internal fixation, 8 cases experienced lateral femoral cutaneous nerve injury postoperatively, all of which recovered sensation after 3 months; 1 case using LC-II screws experienced screw loosening postoperatively and was advised to reduce activity, then the screw was removed after fracture healing at 6 months postoperatively; 1 case using anterior ring channel screws experienced surgical site infection postoperatively, which was controlled after debridement.Conclusion:In the treatment of unstable pelvic ring multiple fractures, robot-assisted screw fixation has less blood loss, less fluoroscopy times, high success rate of planning guide needle, satisfactory reduction quality and postoperative function.