Application Of Navigation Real-time Calibration Technique In Posterior Correction Of Adolescent Idiopathic Scoliosis

[Objective]: To explore the difference of nail placement accuracy between navigation real-time calibration technique and ordinary navigation in posterior correction of adolescent idiopathic scoliosis and the clinical application value of navigation real-time calibration technique.[Methods]: A total of 40 patients with adolescent idiopathic scoliosis who were diagnosed by spinal surgery in the First Affiliated Hospital of Hainan Medical University from January 2017 to January 2021 were retrospectively analyzed.According to the use of positioning needle navigation real-time calibration technology,it is divided into navigation calibration group and ordinary navigation group.There were 21 patients with auxiliary nail placement in navigation calibration group and 19 patients in general navigation group.The occurrence of perioperative complications,operation-related data and the score of SRS-22 scale before and after operation in the two groups were recorded.After operation,all patients underwent CT threedimensional reconstruction of the spine,and the screw position was measured and evaluated by our PACS system according to Rao.The accuracy of nail placement was evaluated by classification.[Results]: There were 21 patients with auxiliary screw placement in the navigation calibration group,including 6 male patients(28.57%)and 15 female patients(71.43%).The average age was(14.72 ±2.78)years.A total of 423 screws were implanted in the general navigation group,including 5 male patients(26.32%)and 14 female patients(73.68%).The average age was(15.04 ±3.21)years old,with a total of 398 screws.There was no statistical difference in age,sex ratio,Risser sign and other general data between the navigation calibration group and the ordinary navigation group,but the two groups were comparable.In the perioperative navigation calibration group,there were 1 case of wound hematoma,1 case of pulmonary infection and 1 case of delayed healing of incision infection.In the general navigation group,non-screw-related transient neurological impairment occurred in 1 case,intercostal neuralgia in 2 cases and pleural effusion in 1 case.The perioperative condition of the two groups was improved and discharged after clinical symptomatic treatment.the follow-up time of the two groups was 12 to 26 months,with an average of 17.4 months.at the last followup,there was no screw loosening and fracture and neurovascular injury in the two groups.After operation,according to the three-dimensional image of CT in PACS system,Rao.The evaluation of grading standard found that the nail placement rate of grade 0(no penetration)and grade 1(penetration of cortex < 2mm)in the navigation calibration group was 91.96%,which was higher than that in the ordinary navigation group(81.16%).There was a statistical difference between the two groups(P = 0.029).The rates of rupture of medial wall,lateral wall,anterior wall and intervertebral foramen in the navigation calibration group were 5.44%,6.15%,3.07% and 1.65%,respectively,which were lower than 6.78%,12.81%,4.02% and 2.01% in the general navigation group,but there was statistical difference only in the rupture of the lateral wall(P=0.033).The nailing rate of grade 2 and 3 in the navigation calibration group(penetrating cortex ≥ 2mm)was 5.44% 2.60%,which was lower than that of 10.80%(8.04%)in the general navigation group(P < 0.05).The difference was statistically significant.All the patients in the navigation calibration group and the general navigation group were scored with SRS-22 scale before and after operation.There was no significant difference in the score between the two groups,but there was significant difference between the two groups.[Conclusion]: The excellent and good nail placement rate of the navigation calibration group was better than that of the ordinary navigation group,and the nailing rate of grade2 and 3 was lower than that of the ordinary navigation group.The navigation real-time calibration technology can also dynamically monitor the direction and degree of navigation offset during the operation,and can provide a reference for operators to adjust the navigation equipment in a controllable range to improve the accuracy of screw placement,so as to reduce the wall breaking rate of pedicle screws.it has a certain clinical application value to improve the safety of screw placement and reduce the incidence of long-term complications.