Robot-assisted femoral shaft reduction cuts fluoroscopy by about two-thirds and improves alignment in a 30-patient controlled study
Source: International Orthopaedics·Published: 2025
Authors: Zhao C, Xiao H, Cao Q, Bei M, Li B, Song Y, Zhu G, Wu X·DOI: 10.1007/s00264-025-06623-zOpen Access
Key table: Table 1 — Demographics and operative data comparing the robot-assisted and conventional arms side by side, including the intraoperative fluoroscopy count, length discrepancy, and anteversion difference that drive the paper’s conclusion. View in source
Bottom line: Robot-assisted reduction reduced intraoperative fluoroscopy events from 117 to 37 on average, improved femoral length discrepancy from 4.2 to 1.7 mm, and improved anteversion error from 13.8° to 3.7°. Total reduction time and blood loss were unchanged. Sample size was 30 and allocation was not randomized.
What the study did
Thirty adults with fresh femoral shaft fractures at a single Beijing center were allocated to robot-assisted closed reduction and intramedullary nailing (n = 15) or conventional fluoroscopy-guided reduction and nailing (n = 15) in a prospective non-randomized controlled design. The robot-assisted group used an orthopedic surgical navigation system to guide the reduction step. Primary outcomes were reduction time, total operative time, intraoperative fluoroscopy count, blood loss, and post-operative reduction error measured on imaging (femoral length discrepancy and anteversion difference).
What they found
Baseline characteristics were similar between groups. The robot-assisted group required significantly fewer intraoperative fluoroscopies (36.67 ± 25.41 vs 117.26 ± 61.28, P < 0.001). Post-operative femoral length discrepancy was lower (1.74 ± 1.37 mm vs 4.16 ± 2.67 mm, P = 0.004) and anteversion difference was lower (3.66 ± 3.37° vs 13.81 ± 9.58°, P = 0.001). Intraoperative blood loss (207.33 ± 119.91 mL vs 240.00 ± 139.13 mL, P = 0.497) and reduction time (74.27 ± 27.38 min vs 69.73 ± 34.10 min, P = 0.691) did not differ significantly.
Why it matters for orthopedic practice
The dosimetric case for robot-assisted long-bone reduction has been mostly theoretical. This study puts a concrete number on it: roughly 80 fewer fluoroscopy shots per case, translating to meaningful reduction in radiation exposure to the surgeon, OR staff, and patient over a year of trauma volume. Alignment gains are equally notable, as malunion and leg length inequality drive long-term disability and reoperation after femoral shaft fixation. The data suggest a legitimate role for robotic navigation in high-volume trauma centers, assuming the platform is available and the learning curve has been climbed.
Limitations
The study enrolled 30 patients from a single center, with allocation described as non-randomized, both of which limit generalizability. Two of the authors are affiliated with the robot manufacturer, a potential source of bias that readers should weigh. Follow-up was short and no clinical outcomes such as union time, functional scores, or reoperation rate were reported. The conventional arm used fluoroscopy alone without modern adjuncts such as CT-guided navigation, which may narrow the comparative gap. A larger multicenter randomized trial with patient-reported outcomes would strengthen the evidence base.
Zhao C, Xiao H, Cao Q, Bei M, Li B, Song Y, Zhu G, Wu X. Robot-assisted closed reduction of femoral shaft fractures: a prospective controlled study. Int Orthop. 2025;49(9):2251-2261. doi:10.1007/s00264-025-06623-z
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