Abstract
STUDY DESIGN: This was a retrospective study. OBJECTIVE: The purposes of this study were to compare the characteristics of odontoid parameters between subjects with and without adolescent idiopathic scoliosis (AIS) and to investigate the correlation between odontoid parameters and other cervical sagittal parameters. SUMMARY OF BACKGROUND DATA: Previous studies have shown that odontoid parameters are important parameters related to cervical sagittal alignment. However, there are few reports on odontoid parameters in patients with AIS. MATERIALS AND METHODS: Between November 2022 and November 2023, 42 AIS patients (AIS group) underwent standing erect whole-spine posteroanterior and lateral full-spine digital radiography. Correspondingly, 28 sex- and age-matched normal adolescents (control group) were enrolled. Odontoid parameters and other cervical sagittal parameters, including odontoid incidence (OI), odontoid tilt (OT), C2 slope (C2S), T1 slope (T1S), C0-2 angle, C2-7 angle (CL), and T1S-CL, were measured via standing plain radiographs. Pearson correlation and linear regression were used to compare the sagittal parameters between the 2 groups. RESULTS: There were no significant differences between the 2 groups in terms of cervical sagittal parameters, including OI, OT, C2S, C0-2 angle, or T1S-CL. After Bonferroni correction, in the AIS group, OI was significantly correlated with C2S ( r =0.37, P <0.05) and T1S-CL ( r =0.34, P <0.05). OI matched with the C0-2 angle ( r2 =0.081), and T1S-CL ( r2 =0.093). In the control group, after Bonferroni correction, OI was significantly correlated with C2S ( r =0.49, P <0.01) and T1S-CL ( r =0.40, P <0.05). OI matched with T1S-CL ( r2 =0.130). CONCLUSIONS: OI is a constant cervical anatomic parameter closely related to other cervical sagittal parameters and was not affected by adolescent idiopathic scoliosis.