A study on the accuracy of screw placement in the apical region of patients with Lenke1 adolescent idiopathic scoliosis under intraoperative navigation

Abstract

Abstract Background To compare the accuracy and deviation direction of pedicle screw placement in the apical region of patients with Lenke type 1 adolescent idiopathic scoliosis (AIS) under navigation using navigation calibration techniques, and to analyze the related factors affecting the deviation of screw placement under navigation and the clinical significance of navigation calibration techniques. Methods This was a retrospective analysis of 43 patients who were diagnosed with Lenke type 1 AIS in our hospital from October 2017 to October 2020 and underwent posterior scoliosis correction and internal fixation with navigation assistance. According to whether navigation calibration technology was used during the operation, 43 patients were divided into two groups: the navigation group (n = 21) and the navigation calibration group (n = 22). The basic information, Risser sign, preoperative and postoperative Cobb angle and postoperative correction rate of the two groups were recorded, and the accuracy of screw placement in the apical vertebral region was evaluated according to the Rao classification. Results A total of 414 screws were placed between the two groups, 202 in the navigation group and 212 in the navigation calibration group. The excellent and good rates of screw placement in the apical region, concave side and convex side were 85.76%, 78.49% and 92.73%, respectively, in the navigation calibration group, which were significantly higher than 76.47%, 66.19% and 85.77%, respectively, in the navigation group (P = 0.001, P = 0.007, P = 0.016). The rate of grade 2 screw placement in the navigation calibration group (9.0%) was significantly lower than that in the navigation group (15.3%) (P = 0.04). In addition, the rates of parietal vertebral region and concave and convex medial wall ruptures in the navigation calibration group were 2.4%, 3.8% and 0.9%, respectively, which were significantly lower than 11.9%, 16.0% and 7.8%, respectively, in the navigation group, and the difference between the two groups was statistically significant (P = 0.001, P = 0.004, P = 0.011). In addition, the wall-breaking rates of the apical vertebral region and its concave and convex medial walls in the navigation calibration group were 2.4%, 3.8%, and 0.9%, respectively, which were significantly lower than those in the navigation group (11.9%, 16.0%, and 7.8%, respectively). The difference between the two groups was statistically significant (P = 0.001, P = 0.004, P = 0.011). No spinal cord or neurovascular injury occurred in either of the two groups. Conclusion Compared with simple navigation, a simple calibration technique can effectively prevent navigation deviation, significantly improve the accuracy of screw placement in the apical vertebral region of AIS patients, reduce the perforation rate of the medial wall of the misplaced screw, and improve the safety of the operation.