Single dynamic structured light navigation for minimally invasive cervical pedicle screw insertion: Achieving complex design and precise puncture

AIM: The aim of this study was to explore the preoperative design and intraoperative navigation for minimally invasive cervical pedicle punctures and to validate the feasibility and accuracy of a single dynamic structured light navigation system. METHODS: Nine bovine cervical spine bone models were created for preoperative CT scanning and three-dimensional reconstruction. Preoperative segmentation of the vertebral bodies and design of the navigation channels were conducted. During the procedure, structured light scanning was employed to capture the intraoperative scene and facilitate registration. The navigation channel was adjusted to align with the preoperative design. A 2.0 mm stainless steel Kirschner wire was subsequently inserted into each pedicle through separate punctures. The position of the Kirschner wire was evaluated via the Neo classification system. Intraoperative root mean square (RMS) values and registration accuracy were recorded. The deviations and angles of the preoperative and postoperative entry and exit points were calculated on the basis of the three-dimensional coordinates of these points. Statistical analyses were performed to assess differences in the X, Y, and Z coordinate values of the entry and exit points before and after the procedure. RESULTS: A total of 124 Kirschner wires were inserted, and the Neo classification evaluation for all models was Grade 0, with a puncture accuracy of 100%. There was high consistency between the postoperative Kirschner wire trajectories and the preoperative design. The average intraoperative RMS and registration accuracies were 0.424 ± 0.12 mm and 0.01 ± 0.008 mm, respectively. The preoperative and postoperative entry point deviation was 0.904 ± 0.419 mm, and the exit point deviation was 1.253 ± 0.607 mm. The entry and exit point deviation angle was 0.918 ± 0.421°. The deviation may be related to bone surface factors. CONCLUSION: A single dynamic structured light navigation system is capable of performing simultaneous preoperative complex design, intraoperative scene scanning, static registration, and dynamic tracking of piercing instruments, thereby enabling high-precision minimally invasive punctures.