Robotic S2Alar iliac screw placement: Comparing conventional and robot assisted minimally invasive techniques

To evaluate the clinical, imaging, and peri-operative results of robotic-guided conventional versus robot assisted minimally invasive techniques for S2 Alar-Iliac (S2AI) screw placement during spinopelvic fixation.

A prospective comparative study comparing the clinicoradiological parameters of patients undergoing conventional robotic assisted S2AI screw insertion and those who underwent Robotic minimally invasive percutaneous screw insertion between November 2023 and June 2025 was done. Data collected included demographics, operative time, intraoperative blood loss, postoperative pain, hospital stay, radiographic angles, radiation dose, screw accuracy, and complications.

A total of 102 patients underwent spinopelvic fixation during the study period - 56 patients (116 screws) underwent conventional robotic assisted S2AI screw insertion and 46 patients (92 screws) underwent robot assisted percutaneous S2AI screw insertion. Both groups showed accurate screw placement without any intraoperative adverse events. The robot assisted percutaneous group had markedly reduced postoperative VAS scores (3.2 ± 1.1 vs. 5.8 ± 1.5, p < 0.0001) and reduced length of stay (3.1 ± 0.9 vs. 5.0 ± 1.3 days, p < 0.0001). Intraoperative blood loss,wound complications and operative time were also lesser in the robot assisted group but was not statistically significant. All other radiographic parameters and radiation dose were comparable across groups.

Robot assisted minimally invasive S2AI screw placement is a safe and efficient alternative to the conventional open technique. It offers comparable radiographic accuracy and biomechanical stability, with the added benefits of reduced postoperative pain and shorter hospital stay.