The Radiographic Outcomes of Cannulated Screws Insertion with Robotic-Assisted Navigation in Lenke Type 1 Adolescent Idiopathic Scoliosis Author information

Lianlei Wang^1,2Zhihao Ma^1,3Su Junxiao⁴Zhiguo Ding⁵Tian Yonghao¹Suomao Yuan¹Shiqing Feng^1,2Xinyu Liu^1*

• ¹Department of Orthopedics, Qilu Hospital of Shandong University, Jinan, China
• ²Tianjin Medical University General Hospital, Tianjin, China
• ³Department of Orthopaedics, Chinese PLA General Hospital, Beijing, China
• ⁴Department of Orthopedics, Gansu Provincial Hospital, Lanzhou, Gansu Province, China
• ⁵Shouguang City People's Hospital, Weifang, China

Background: Adolescent idiopathic scoliosis (AIS) is the most common spine deformity in adolescent children. Pedicle screw systems play an important role in AIS surgeries. The accuracy of pedicle screw insertion have been greatly improved with robot-assisted system. Besides, clinical evidence suggests that the application of uniplanar cannulate pedicle screws improves the accuracy of pedicle screws and facilitates the derotation of the apical vertebrae in AIS surgery compared with multiaxial pedicle screws. This study aims to assess the radiographic outcomes of cannulated screws insertion with robotic-assisted navigation in Lenke type 1 AIS.Methods: A total of 144 patients with Lenke type 1 AIS were retrospectively included in this study. Among which, sixty-four patients underwent uniplanar cannulated screws insertion at periapical levels with robotic-assisted navigation and multiaxial cannulated screws insertion at other levels with freehand (group A); fifty patients underwent uniplanar cannulated screws insertion at periapical levels and multiaxial cannulated screws at other levels with freehand (group B); thirty patients underwent routine multiaxial pedicle screws insertion at all levels by freehand (group C). The characteristics, operative details, radiographic parameters, and pedicle screws insertion were recorded. One-way ANOVA and the chi-squared test were performed to compare differences between groups. Results: The groups did not significantly differ regarding age, sex ratio, and operative time. Group A had a significantly higher patient radiation dose(P<0.001), but significantly lower surgeon radiation dose(P=0.002). Group A and B showed significant difference compared with group C at post-operative Cobb angle(P=0.03), coronal correction rate(P<0.001) and apical vertebral derotation rate. Other radiographic data did not significantly differ. At periapical levels, a total of 427 uniplanar cannulated screws were inserted in group A and 266 in group B. Group C had 187 routine multiaxial screws inserted at periapical levels. Group A(4.7%) had lower rate of screw misplacement compared with group B(10.5%) and group C(11.2%).Conclusion: Robot system achieves higher pedicle screws insertion accuracy at periapical levels in AIS. Uniplanar cannulated pedicle screws placement has better coronal correction and derotation effect in AIS correction. Robot system reduces the amount of radiation exposure to surgeons; however, it increases the amount of radiation exposure to patients.