ACCURACY OF INTRAOPERATIVE COMPUTED TOMOGRAPHY NAVIGATION IN ONE REGISTRATION SCAN FOR PEDICLE SCREW PLACEMENT IN ADOLESCENT IDIOPATHIC SCOLIOSIS

Purpose:Pedicle screw insertion in a deformed and rotated pedicle in scoliosis is technically demanding. A multislice spiral intraoperative computed tomography (iCT)-guided navigation system can assist pedicle screw insertion. However, no studies have been performed to evaluate the pedicle diameter and accuracy of pedicle screw placement in patients with adolescent idiopathic scoliosis (AIS) using one scan iCT-guided navigation. Methods:This was a retrospective cohort study. iCT was performed before screw insertion and after screw insertion. The pedicle diameters in all planned surgical levels were measured. A pedicle with a maximal diameter of less than 4 mm was considered narrow. A screw with a breach distance of ≤2 mm was considered accurate. Results:Twenty-nine consecutive patients with AIS received surgery with 415 pedicle screws inserted in 580 planned screw insertion pedicles. Twenty-five patients had been found to have narrow pedicles (86.2%). Overall, the screw accuracy rate was 98.6% (409/415). Thirty-eight screws were inserted in narrow pedicles and the screw accuracy was 84.2% (32/38). There were no major complications after screw insertion. Conclusion:One scan iCT-guided navigation provides a high degree of safety and screw accuracy of 98.6% for pedicle screw placement in AIS.