What are the essential working components of an intraoperative spinal navigation system?
An Intraoperative Spinal Navigation System consists of four major components:
• Imaging modality: Navigation may be based on use of an intraoperative imaging modality such as a 3D CT or CT-like scanner or 3D fluoroscopy scanner. Alternatively, imaging data obtained intraoperatively can be matched with preoperative CT data and used to guide surgery.
• Reference frame: Provides a fixed point of reference to which navigated instruments are measured and displayed. Common sites for attachment of a reference frame (also referred to as a dynamic reference array) include the posterior spinal elements or ilium.
• Reflective light camera scanner: Detects both the reference frame and the navigated instruments in a 3D grid, and sends the positional coordinates to the computer workstation.
• Marker spheres: Reflective spheres are attached to the navigated instruments and are tracked by the reflective camera on the navigation station.
• Computer workstation with appropriate software that integrates the intraoperative image and positional coordinates from the scanner to provide a real-time graphical representation of the navigated instruments in the spine
