Study on the accuracy of thoracolumbar pedicle screw installation assisted by O-arm navigation

Abstract

Objective To evaluate the accuracy and reliability of O-arm-based thoracolumbar pedicle screw installation. Methods A retrospective review was conducted on 75 patients who had undergone thoracolumbar pedicle screw fixation assisted with O-arm navigation (navigation group, n=32) and C-arm fluoroscopy ( fluoroscopy group, n=43) from March to October 2014. All the patients were assessed with X-ray and CT images after operation. Accuracy of screw installation in both groups was compared. In navigation group, screw directions were measured on the sagittal and axial images of intra-operative navigation and post-operative CT scanning to evaluate the concordance. Results In fluoroscopy group, a total of 206 pedicle screws were placed with the one-time success rate of 93.2% and accuracy of 90.8% for screw placement, and one misplaced screw (grade Ⅲ) led to L3 nerve root symptom. In navigation group, a total of 226 pedicle screws were placed with the one-time success rate of 100% and accuracy of 96.9% for screw placement, and no screw was grade Ⅲ. Further, there were no significant differences in screw directions on the sagittal and axial images between intraoperative navigation and post-operative CT scanning (P>0.05). Conclusion O-arm navigation that provides high-resolution images and high precision improves the accuracy of thoracolumbar pedicle screw installation, and possesses good reliability. Key words: Spinal fractures; Surgery, computer-assisted; Thoracic vertebrae; Lumbar vertebrae; Pedicle screws