C2–C3 vertebral disc angle: An analysis of patients with and without cervical spondylotic myelopathy

Study design Retrospective analysis. Objective To define C2–C3 vertebral disc angle (VDA) in patients with and without cervical spondylotic myelopathy. Summary of background data C2–C3 VDA is a new radiological index of cervical spine alignment. Recent studies have suggested that high postoperative values are associated with greater mechanical complications in patients with cervical spondylotic myelopathy. However, normative values for patients without myelopathy has yet to be defined. Methods Patients with and without cervical myelopathy between 2017 and 2019 were included. Inclusion criteria were patients above 18 years of age with antero-posterior (AP) and lateral (LAT) cervical X-rays. In the non-myelopathic group, patients were excluded if they had neurological symptoms or deficits, presence of cervical axial pain, previous spinal surgery, or diagnosis of either spondylolisthesis or scoliosis. In the myelopathic group, patients were excluded if they had previous spinal surgery. Radiological indices evaluated include: C2–C3 disc angle, C2–C7 Cobb angle, C7 sagittal vertical axis, T1 slope. Results In total, 99 patients without myelopathy and 22 patients with myelopathy were identified and analyzed. In patients without myelopathy, the mean for C2–C3 VDA was 25.9±7.9. For patients with myelopathy, preoperative values were 24.4±10.0 and 27.1±7.9 postoperatively. No statistically significant differences were found between patients with and without myelopathy. C2–C3 disc angle was not correlated with age (R=−0.173). Conclusion This study did not find statistically significant differences in C2–C3 VDA values between patients with and without cervical myelopathy. This study provides normative data for C2–C3 vertebral disc angle in patients with and without cervical spondylotic myelopathy. Furthermore, C2–C3 vertebral disc angle may be independent from age.