Limitations of current robot-assisted pedicle screw insertion systems

OBJECTIVE As robot systems for spine surgery have been developed, they have demonstrated a high degree of accuracy in screw placement without sacrificing safety or surgical efficiency. These robotic systems offer preoperative planning and real-time feedback to enhance surgical precision and mitigate human error. Nevertheless, limitations to their optimal performance remain. The authors analyzed the initial 100 cases of pedicle screw placements performed using the Mazor X robot at their institution, presenting case examples to illustrate the limitations that were experienced, and reviewed current literature on the limitations of robot-assisted spine surgery, emphasizing their impact on accuracy and safety. METHODS This was a retrospective review of the first 100 cases of robot-assisted pedicle screw placement at the authors’ institution between December 2019 and June 2024. All intraoperative CT scans were reviewed for screw accuracy. Malpositioned screws, near misses (screw deviation without injury to the patient), or abandoned robot-assisted attempts were identified, and the underlying reasons were evaluated to determine the limitations of current robot technology. RESULTS Of the first 100 cases of robot-assisted pedicle screw placement, there were 20 screw-related complications, of which 14 were near misses, 1 involved neurological injury caused by screw malposition, and 5 were cases in which a robot-assisted attempt was abandoned before manual screw placement. The authors identified the following limitations with current robot technology: registration errors, spine movement after registration, patient body habitus, artifact from metallic implants, poor bone differentiation, skiving, soft-tissue interference, and physical constraints. CONCLUSIONS Despite the advancements of spine robot systems, several limitations persist, especially in mobile or unstable spine locations and around critical structures. The authors’ experience, with provided case examples, further illustrates technical nuances important to understanding and navigating around these limitations. The need for standardized reporting metrics to evaluate and classify emerging technologies is highlighted, emphasizing ongoing technological innovation to enhance the efficacy of robot-assisted spine surgery.