Insertion of transpedicular screws in the lumbar spine with use of computed navigation

Abstract

Transpedicular fixing is widely used in spinal surgery. But the traditional control techniques, such as fluoroscopy and visual anatomical reference points for positioning screws, do not exclude complications. The use of computed navigation systems makes it possible to solve this problem. A system with involvement of preoperative computed tomography and intraoperative fluoroscopy makes it possible to monitor instruments relative to anatomical elements of the vertebral column in the real-time mode. Computed surgical navigation was employed in the process of intervention on the lumbar spine in 112 patients. The operations were performed on 52 patients for spondylolisthesis, 31 for degenerative stenosis, and 29 for injuries of the lumbar spine. Data of preliminary CT scanning) were used in 93 cases and those of intraoperative fluoroscopy “FluoroNav” program in 21. In order to reveal the position of screws in the postoperative period, all the patients underwent CT. In 109 cases, no injuries of the cortical plate of the arch root were found out and the position of screws was regarded as correct. Three cases developed an injury on the medial wall of the arch root: “FluoroNav” program was used in two of them and “FluoroMerge” program in one. In all three cases, revision operations were made to reinsert screws. No neurological postoperative complications (appearance of new disorders or aggravation of the available ones) were observed. The positioning of 6 screws from the moment of fixation of a reference frame to the positioning of the last screw lasted 30 minutes. Computed navigation made it possible to position transpedicular screws with high precision, thereby minimizing the risk of operation-dependent complications. Besides, the surgical procedure duration and the number of made roentgenograms become reduced.