The learning curve in robot-assisted pelvic canal screw placement: evaluating procedure efficiency, technical fluency, and screw accuracy

Abstract Background Robot-assisted surgery has shown promise in improving the accuracy of pelvic canal screw placement, yet the learning curve associated with this technology remains underexplored. This study aims to quantitatively evaluate the learning curve for robot-assisted pelvic canal screw placement, focusing on procedure efficiency, technical fluency, and screw accuracy. Methods A retrospective analysis was conducted on 1274 patients who underwent robot-assisted pelvic screw placement performed by a single surgeon and a consistent surgical team between January 2020 and May 2025. Patients were categorized into six groups based on screw type and trajectory: S1 screw (Group A), S2 screw (Group B), anterior column antegrade screw (Group C), anterior column retrograde screw (Group D), lateral compression type II (LC-II) antegrade screw (Group E), and LC-II retrograde screw (Group F). To evaluate the learning curve, the first 30 consecutive cases from each group were chronologically and equally divided into initial, middle, and final subgroups. Primary outcome measures, including intraoperative fluoroscopy frequency, screw planning time, number of guidewire adjustments, and total operative time, were recorded and compared across these subgroups. The learning curve was analyzed using the case sequence number (1–30) from each group as the independent variable and the primary outcome measures as dependent variables. Postoperative screw accuracy was assessed for all placed screws using the Smith grading system. Results Overall screw placement accuracy was 98.6%. Significant improvements in all primary outcome measures were observed between the initial and middle subgroups ( P < 0.05), with stabilization thereafter. No significant differences were noted between the middle and final subgroups ( P > 0.05). The learning curve reached a plateau after approximately 5 to 15 cases, which varied by screw type: S1 screws (5 cases), S2 screws (7 cases), anterior column antegrade screws (10 cases), anterior column retrograde screws (12 cases), LC-II antegrade screws (10 cases), and LC-II retrograde screws (15 cases). Conclusion Robot-assisted pelvic canal screw placement is highly accurate, with a quantifiable learning curve of 5–15 cases to achieve procedural proficiency. These findings provide a benchmark for training programs and support the role of robotic technology in standardizing complex pelvic fracture surgeries.