gms | German Medical Science

Objective: CT-navigated implantation of pedicle screws in comparison to the fluoroscopy-guided approach seems to be a safe and simpler method for the implantation of pedicle screws into the thoracolumbar spine. The present study was carried out with the aim of drawing a comparison between the two methods in terms of procedure complexity, precision of screw placement and perioperative complications.

Methods: Operation data from a total of 1,006 patients were analyzed. 505 procedures were carried out with CT navigation and 501 were fluoroscopy guided. In the navigation group 774 screws were implanted into the thoracic spine, 1,648 were placed into the lumbar spine. In contrast, 1,392 lumbar and 608 thoracic screws were implanted in the fluoroscopy group.

Results: Screw malposition was evident in 9.6% of the thoracic and 3.6% of the lumbar screws in the navigation group.In the fluoroscopy group on the other hand, 38.2% of the thoracic and 6.1% of the lumbar screws showed malpositioning. This difference becomes even clearer when excluding the Th11- and Th12-level from the thoracic group resulting in >50% malpositioning of thoracic pedicle screws in the fluoroscopy group. Reoperations due to malpositioning were needed in 22 patients (4.4%) of the fluoroscopy group and in 6 patients (1.2%) of the navigation group. The operation times are significantly prolonged by the use of CT-navigation.

Conclusions: CT-navigation markedly increases the security of screw placement into the middle and upper thoracic spine and is a must-have-tool when dealing with instrumentation of these levels. When considering instrumentation of the lumbar and lower thoracic spine, the advantage of navigation in comparison to fluoroscopy partly disappears, especially because of longer operation times and the complexity of the procedure. It seems to be advantageous if both techniques are routinely established at the department. Intraoperative CT scan should be performed in every case.