An Assistive Image-Guided Surgical Robot System Using O-Arm Fluoroscopy for Pedicle Screw Insertion: Preliminary and Cadaveric Study

BACKGROUND: The biplane fluoroscopy guided robot system (BFRS) was developed for surgical robotic systems, minimally invasive surgeries, and cooperative robotic systems, as well as enhanced surgical planning and navigation with preoperative and intraoperative image data. OBJECTIVE: To propose a novel surgical robot system for percutaneous pedicle screw insertion. METHODS: The BFRS consists of an O-shaped biplane fluoroscope (O-arm), a surgical planning and operating system, and an assistive robot. Each part of the BFRS has a role in conducting percutaneous pedicle screw placements. To evaluate BFRS accuracy, each part was analyzed, and to assess the safety and feasibility of percutaneous pedicle screw insertions with the BFRS, cadaveric studies involving 14 levels in the thoracic and lumbar spine regions were conducted on 2 cadavers. RESULTS: Errors in each part of the system and within the entire system were evaluated. The accuracy of generating coordinates using O-arm images was 0.30 +/- 0.15 mm. The robot demonstrated a duplication value of 4.97 mm RMS and an accuracy of 0.358 mm RMS. Total system error was 1.38 +/- 0.21 mm. The results of the cadaveric studies show that inserted pedicular screws were adequately located within the spine with no unexpected malpositioning of the screws. The axial angle difference between planned and postoperative data was 2.45 +/- 2.56 degrees, and the sagittal angle difference was 0.71 +/- 1.21 degrees. CONCLUSION: The BFRS might be helpful in improving the accuracy of percutaneous pedicular screw insertion procedures. In the future, we will attempt to improve the accuracy and reliability of the BFRS and to determine new clinical applications for the BFRS.