Novel lateral fiducial marker positioning technique eliminates registration failures in high-body mass index patients during robot-assisted spine surgery
Source: PubMed Central Open Access, NCBI / U.S. National Library of Medicine
ABSTRACT Background: Unsuccessful intraoperative computed tomography (CT) registration creates significant technical barriers limiting robot-assisted spine surgery implementation in obese populations due to imaging system field-of-view constraints exceeding patient dimensions. Materials and Methods: This consecutive series evaluated 63 patients with body mass index exceeding 40 kg/mundergoing robot-assisted thoracolumbar fusion between October 2023 and November 2024. A lateral reference marker positioning strategy exploited O-arm’s asymmetric spatial coverage (40 cm transverse vs. 15 cm anteroposterior). Systematic preliminary radiographic assessment guided positioning selection, with lateral placement implemented when scout images demonstrated inadequate fiducial visualization or when patient dimensions approached field-of-view limitations. Results: Lateral positioning was implemented in 17 (27.0%) cases. This approach eliminated severe registration failures, with zero patients requiring more than one reattempt compared to 3 (6.5%) patients in the standard positioning cohort requiring two or more reattempts. Ultimate registration success reached 100% across all cases. First-attempt success was achieved in 82.5% of procedures. Patients requiring reattempts demonstrated significantly prolonged O-arm acquisition intervals (30.3 vs. 19.4 min,= 0.003) and elevated radiation exposure (61.6 vs. 38.3 mGy,< 0.001). Optimal pedicle screw positioning (Gertzbein–Robbins Grade A + B) was
Abstract
ABSTRACT Background: Unsuccessful intraoperative computed tomography (CT) registration creates significant technical barriers limiting robot-assisted spine surgery implementation in obese populations due to imaging system field-of-view constraints exceeding patient dimensions. Materials and Methods: This consecutive series evaluated 63 patients with body mass index exceeding 40 kg/mundergoing robot-assisted thoracolumbar fusion between October 2023 and November 2024. A lateral reference marker positioning strategy exploited O-arm’s asymmetric spatial coverage (40 cm transverse vs. 15 cm anteroposterior). Systematic preliminary radiographic assessment guided positioning selection, with lateral placement implemented when scout images demonstrated inadequate fiducial visualization or when patient dimensions approached field-of-view limitations. Results: Lateral positioning was implemented in 17 (27.0%) cases. This approach eliminated severe registration failures, with zero patients requiring more than one reattempt compared to 3 (6.5%) patients in the standard positioning cohort requiring two or more reattempts. Ultimate registration success reached 100% across all cases. First-attempt success was achieved in 82.5% of procedures. Patients requiring reattempts demonstrated significantly prolonged O-arm acquisition intervals (30.3 vs. 19.4 min,= 0.003) and elevated radiation exposure (61.6 vs. 38.3 mGy,< 0.001). Optimal pedicle screw positioning (Gertzbein–Robbins Grade A + B) was maintained regardless of technique (lateral 97.6% vs. standard 96.9%,= 0.650). Conclusion: Lateral reference marker positioning resolves CT registration challenges in obese patients undergoing robot-assisted spine surgery, achieving universal success using existing equipment without additional capital investment.