Intelligent Robot-Assisted Fracture Reduction for Pelvic Fractures:A Clinical Study

Xinyu Fan¹Jianlin He¹Baochuang Qi²Hu Zhang¹Gang Li¹Xingqiang Liu³Wei Yu⁴Nuocheng Yang⁴Yin Yang⁵Yongqing Xu^1*

• ¹Department of Orthopedic Surgery, The 920th Hospital of Joint Logistics Support Force, Kunming, China
• ²Yunnan Provincial Hospital of Chinese Medicine, Kunming, China
• ³Pangjiang coal and power group hospital, Guizhou, China
• ⁴Dali University, Dali, China
• ⁵Department of Orthopedics, Dali Bai Autonomous Prefecture Peoples’s Hospita, Dali, China

Objective: To evaluate the safety, feasibility, and radiographic outcomes of an intelligent robot-assisted fracture reduction (RAFR) system in the minimally invasive treatment of fresh unstable pelvic ring injuries. Methods: In this single-center retrospective case series, 32 consecutive patients with unstable pelvic ring injuries (Tile type B or C) treated between August 2024 and April 2025 underwent minimally invasive closed reduction and internal fixation using the RAFR system. The system combines preoperative CT-based three-dimensional reduction planning, intraoperative cone-beam CT (CBCT) registration, an optical tracking system, a table-mounted passive holding arm, and a robotic arm with dual force–position monitoring. Operative time, intraoperative blood loss, and fluoroscopic exposures were recorded. Postoperative CT was used to measure residual displacement, which was graded according to Matta criteria, and the excellent-to-good rate was calculated. Functional outcomes were assessed using the Majeed score at the final follow-up. Results: All 32 procedures were completed using a closed, minimally invasive approach without conversion to open reduction. Median (IQR) operative time was 270 (225–311) minutes, blood loss was 150 (100–300) mL, and fluoroscopic exposures were 35 (30–45). Median residual displacement on CT was 4.0 (3.0–8.0) mm. According to Matta criteria, 17 patients (53.1%) had excellent, 12 (37.5%) good, and 3 (9.4%) fair reductions, yielding an excellent-to-good rate of 90.6%. Two patients were lost to follow-up; among the remaining 30 patients, no major complications such as deep infection, implant failure, or iatrogenic neurovascular injury were observed, and the mean Majeed score was 76.7 ± 12.0. Conclusion: The RAFR system enabled closed reduction and percutaneous fixation of a heterogeneous cohort of unstable pelvic ring fractures with high rates of satisfactory reduction and favorable short-term functional recovery. These preliminary findings support the clinical feasibility and safety of robot-assisted closed reduction for unstable pelvic fractures and provide a basis for future comparative and multicenter studies.