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Avoidance of wrong-level thoracic spine surgery: intraoperative localization with preoperative percutaneous fiducial screw placement.

OBJECT
The accurate intraoperative localization of the correct thoracic spine level remains a challenging problem in both open and minimally invasive spine surgery. The authors describe a technique of using preoperatively placed percutaneous fiducial screws to localize the area of interest in the thoracic spine, and they assess the safety and efficacy of the technique.


METHODS
To avoid wrong-level surgery in the thoracic spine, the authors preoperatively placed a percutaneous 5-mm fiducial screw at the level of intended surgery using CT guidance. Plain radiographs and CT images with reconstructed views can then be referenced in the operating room to verify the surgical level, and the fiducial screw is easily identified on intraoperative fluoroscopy. The authors compared a group of 26 patients who underwent preoperative (often outpatient) fiducial screw placement prior to open or minimally invasive thoracic spine surgery to a historical group of 26 patients who had intraoperative localization with fluoroscopy alone.


RESULTS
In the treatment group of 26 patients, no complications related to fiducial screw placement occurred, and there was no incidence of wrong-level surgery. In comparison, there were no wrong-level surgeries in the historical cohort of 26 patients who underwent mini-open or open thoracic spine surgery without placement of a fiducial screw. However, the authors found that the intraoperative localization fluoroscopy time was greatly reduced when a fiducial screw localization technique was employed.


CONCLUSIONS
The aforementioned technique for intraoperative localization is safe, efficient, and accurate for identifying the target level in thoracic spine exposures. The fiducial marker screw can be placed using CT guidance on an outpatient basis. There is a reduction in the amount of intraoperative fluoroscopy time needed for localization in the fiducial screw group.