Where should Scoliometer and EOS Imaging be Applied when Evaluating Spinal Rotation in Adolescent Idiopathic Scoliosis-A Preliminary Study with Reference to CT Images

Study Design: Retrospective study Objective: Our purpose was to evaluate spinal rotation measurement by scoliometer or EOS Imagings with reference to that by CT images, and to clarify their applicability in clinical practice. Methods: Patients with adolescent idiopathic scoliosis (AIS) who were indicated for surgery were enrolled and the informed consents were obtained. The angle of trunk rotation (ATR) was measured by the scoliometer. Apical vertebral rotation (AVR) was measured with EOS Imaging and CT images. Paired T tests were used to compare the measurements between ATR or AVR-EOS and AVR-CT. Pearson correlation analysis was performed to explore the relationship between ATR or AVR-EOS and AVR-CT. Then subgroup analysis was performed. Results: Forty-seven consecutive AIS patients with 62 curves were identified. In the whole group, the ATR, as well as AVR-EOS, was significantly smaller than the AVR-CT. Both ATR and AVR-EOS correlated with AVR-CT, although AVR-EOS correlated better. In thoracic group, there was no significant difference between ATR and AVR-CT (P = .236). A significant correlation was found between ATR and AVR-CT(r = .574, P < .001). In TL/L group, no significant difference was noted between AVR-EOS and AVR-CT (P = .414), and a significant correlation was found between AVR-EOS and AVR-CT(r = .824, P < .001). Conclusion: ATR by scoliometer is numerically similar to AVR by CT and may evaluate the spinal rotation more appropriately in thoracic spine. AVR by EOS is numerically similar to AVR by CT and may be more applicable in TL/L spine. Appropriate methods could be selected according to the location of the curve.