A Novel Augmented-Reality-Based Surgical Navigation System for Spine Surgery in a Hybrid Operating Room: Design, Workflow, and Clinical Applications

Abstract

BACKGROUND Treatment of several spine disorders requires placement of pedicle screws. Detailed 3-dimensional (3D) anatomic information facilitates this process and improves accuracy. OBJECTIVE To present a workflow for a novel augmented-reality-based surgical navigation (ARSN) system installed in a hybrid operating room for anatomy visualization and instrument guidance during pedicle screw placement. METHODS The workflow includes surgical exposure, imaging, automatic creation of a 3D model, and pedicle screw path planning for instrument guidance during surgery as well as the actual screw placement, spinal fixation, and wound closure and intraoperative verification of the treatment results. Special focus was given to process integration and minimization of overhead time. Efforts were made to manage staff radiation exposure avoiding the need for lead aprons. Time was kept throughout the procedure and subdivided to reflect key steps. The navigation workflow was validated in a trial with 20 cases requiring pedicle screw placement (13/20 scoliosis). RESULTS Navigated interventions were performed with a median total time of 379 min per procedure (range 232-548 min for 4-24 implanted pedicle screws). The total procedure time was subdivided into surgical exposure (28%), cone beam computed tomography imaging and 3D segmentation (2%), software planning (6%), navigated surgery for screw placement (17%) and non-navigated instrumentation, wound closure, etc (47%). CONCLUSION Intraoperative imaging and preparation for surgical navigation totaled 8% of the surgical time. Consequently, ARSN can routinely be used to perform highly accurate surgery potentially decreasing the risk for complications and revision surgery while minimizing radiation exposure to the staff.

Augmented reality navigation with intraoperative 3D imaging vs fluoroscopy-assisted free-hand surgery for spine fixation surgery: a matched-control study comparing accuracy

“…It could be argued that ARSN requires additional time for system set-up, attaching the skin markers, planning, and registration resulting in prolonged OR-time. However, we have demonstrated that the time required for CBCT-acquisition, screw path planning and verification amounted to 8% (median of 8 min) of the procedure time 11 . Unfortunately, the retrospectively collected data of the control group only included the total procedure time and the fluoroscopy time could not be calculated for comparison.…”

“…A gearshift or power drill was then used to navigate along the planned path and create a pilot hole, before navigated screw placement using the ARSN system. One camera of the ARSN system provided a "bulls-eye" view along the screw axis while the other 3 cameras provided guidance for alignment of the instruments during navigation 11 . After placement of the screws an intraoperative CBCT was performed to assess screw placement before wound closure 11 .…”

“…One camera of the ARSN system provided a "bulls-eye" view along the screw axis while the other 3 cameras provided guidance for alignment of the instruments during navigation 11 . After placement of the screws an intraoperative CBCT was performed to assess screw placement before wound closure 11 . In the FH group, the screws were placed based on anatomical landmarks and x-ray fluoroscopy was used when necessary.…”

Robotic Spine Surgery and Augmented Reality Systems: A State of the Art

“…For example, AR may assist surgeons in transpedicular screw placement by visualizing the patient anatomy and preplanned drilling trajectories on a visor in real time. 49,50 In 2 cadaveric studies, Elmi-Terander et al 51 utilized a hybrid system involving both navigation and AR and thus called augmented reality surgical navigation (ARSN). After acquiring a 3D CT scan, a 3D reconstruction of the spine with automatic detection the pedicles allowed the planning of screw insertion.…”

Optimization of virtual and real registration technology based on augmented reality in a surgical navigation system

“…Images of lesion points in patients during and before surgery can be obtained using many ways, and different ways had different effects on the operation. In most cases, preoperative images of the patient were obtained by CT or MRI [50,51]. However, images of the patient's focal point during an operation can be obtained using different ways.…”