Study Design: To use a novel modified intraoperative fluoroscopic view for spinal level localization. Objective: To evaluate the safety and utility of the modified oblique fluoroscopic technique for intraoperative localization of distal cervical and proximal thoracic spinal levels. Summary of Background Information: Operative radiographic localization of the cervicothoracic spine using standard anterior-posterior and lateral views is made difficult by its anatomic relationship to the shoulder and upper chest, which produce radiographic shadowing obscuring the spine. Additional image degradation can be caused by muscular patients or those with a high body mass index. An oblique modification of the standard cross table lateral can be used to accurately identify pathologic levels at or across the cervicothoracic junction. This method distinctly demonstrates the bony lamina, which can then be used to count spinal levels. The unique feature of this technique is that the oblique angle removes the shoulder and the majority of the ribs from the active field of view, thereby producing a cleaner and more distinct image. When the gantry angle of the fluoroscope is parallel to the plane of the opposite lamina, it gives a type of "target sign" similar to the trans-pedicular image commonly used in pedicle screw placement. This radiographic sign can be easily identified and recognized across the cervicothoracic junction, even in those patients with a large body mass index or large musculature. Methods: Spinal level was determined intraoperatively through our oblique technique and confirmed in the same patient through standard views with retrograde counting. Postoperative imaging confirmed correct level surgery. Results: Correct spinal level identification was achieved in the distal cervical and proximal thoracic spine by implementation of our novel oblique fluoroscopy technique. Conclusions: The modified oblique cross table fluoroscopy technique allows accurate operative localization across the cervicothoracic junction and well into the thoracic spine.
- Fluoroscopic localization