Image-Guided Navigation in Anterior Cervical Spine Surgery using a Cranial Frame

Background Data: Cervicothoracic, high thoracic, and craniocervical instrumented anterior spinal procedures pose a considerable challenge to the surgeon, mainly because intraoperative imaging by fluoroscopy is inadequate. To a certain extent the surgeon can make use of 3D-fluoroscopy for intraoperative control of the implants. To ease this process, the surgeon can make use of the so-called cranial frame which is attached to the Mayfield clamp, in combination with navigated 3D-fluoroscopy. The use of the cranial frame for navigated anterior craniocervical approaches as in the case of transnasal procedures at the clivus and foramen magnum is quite widespread. In the literature, the use of this technique for spine approaches is limited to a few case reports. Purpose: To present the feasibility of 3D-fluoroscopy navigation in anterior cervical spine procedures with the use of cranial frame. Study Design: Retrospective clinical case cohort. Patients and Methods: We present our experience in the technique of navigation in 5 patients of anterior cervical spine procedures. Anterior instrumented fusion in the cervicothoracic spine was performed in 4 patients and in the last patient anterior C1/2 fixation was performed. We used a system composed of Arcadis Orbic 3D C-arm by Siemens Medical Solutions, Erlangen, Germany, for acquisition of 3D images and the Stealth Station system by Medtronic Inc., Louisville, USA, for navigation. We used a socalled cranial frame for navigation that is fixed to the Mayfield head holder; a preoperative 3D scan was performed in some patients. The intraoperative 3D scan was performed after removal of the retractors, and additional 3D scan was beneficial in some patients during the surgical procedure. Results: Navigation was helpful in identification of the entry points and trajectories of the screws especially in the cervicothoracic region with no need for fluoroscopy. Additional advantage of the use of this system is the possibility of performing intraoperative 3D scan after instrumentation to verify hardware placement. Conclusion: The illustrated cases demonstrate the advantages of 3D-fluoroscopy navigation with use of the cranial frame in the upper transitional zones. Disadvantages of this method are the complex intraoperative draping and logistics and the possible inaccuracy because of long distances and spinal mobility. Carbon Mayfield may facilitate positioning but is not mandatory. (2018ESJ173)