Spino Cranial Angle and Degenerative Cervical Spondylolisthesis

Comparison of Cervical Sagittal Parameters among Patients with Neck Pain and Patients with Cervical Spondylotic Radiculopathy and Cervical Spondylotic Myelopathy

OBJECTIVE

Previous studies have shown that cervical sagittal alignment is strongly associated with cervical deformity, myelopathy, and cervical adjacent-segmental disease, and these cervical sagittal parameters are correlated with health-related quality of life. However, less attention has been paid to cervical sagittal balance in various cervical disorders. This study aimed to compare cervical sagittal parameters between patients with nonspecific neck pain (NS-NP) and patients with cervical spondylotic radiculopathy (CSR) and cervical spondylotic myelopathy (CSM).

METHODS

We retrospectively examined 236 patients from between January 2020 and October 2022. We divided them into three groups (NS-NP, CSR, and CSM) and collected general information and cervical sagittal parameters for these patients. The variation of parameters between the size of these parameters and gender differences was analyzed. Pearson's or Spearman's correlation was applied to analyze the association of cervical sagittal parameters of all patients between the three groups.

RESULTS

There were significant differences in age and sex among the three groups (p < 0.001), with the NS-NP group being the youngest and NS-NP being more common in women. The parameters of cervical sagittal position significantly differed among the three groups (p < 0.05). Pearson's or Spearman's correlation result showed that the C2-C7 Cobb angle was negatively associated with the C2-C7 sagittal vertical angle (SVA), and the C2-C7 Cobb angle and T1 slope (T1s) were negatively associated with the spino-cranial angle (SCA). There was a positive correlation between the C2-C7 Cobb angle and C7 slope (C7s), C2-C7 SVA and T1s, C2-C7 SVA and SCA, and C7s and T1s.

CONCLUSION

This study showed that between the three groups, patients with nonspecific neck pain had smaller SCA, and among patients with NS-NP, women had more significant SCA. The smaller anteroposterior diameter of the thorax in women might explain this difference.

Can C7 Slope Accurately Substitute for an Invisible T1 Slope According to Age and Cervical Morphology in Cervical Lateral Radiographs?

STUDY DESIGN

A retrospective radiologic study.

OBJECTIVES

To identify age-associated changes in T1 slope (T1S) and C7 slope (C7S), as well as the difference between T1S and C7S (△, which was defined as T1S minus C7S) and to explore the cervical morphology that C7S can be the most accurate alternative for the invisible T1S.

METHODS

625 asymptomatic Chinese volunteers received cervical lateral radiographs from August 2021 to May 2022. Occipito-C2 angle (O-C2), C2-7 angle (C2-7), cranial arch, caudal arch, C7S, and T1S were examined. Thereafter, the △ was established. The correlations among T1S, C7S, △ and other cervical sagittal parameters, and between age and other cervical sagittal parameters were evaluated with the Pearson correlation coefficient analysis. Then, analysis of variance (ANOVA) was conducted to compare variations in cervical sagittal parameters among volunteers aged 40 to 59 years, 60 to 64 years, 65 to 69 years, 70 to 74 years, and ≥75 years of age, and among volunteers with 1 lordotic morphology, 2 lordotic morphology, straight morphology, kyphotic morphology, 1 sigmoid morphology, and 2 sigmoid morphology. Linear regression modeling of the correlation between C7S and T1S in various cervical alignment patterns was then established.

RESULTS

△ had the strongest correlation with caudal arch (r = .646), and weakest correlation with cranial arch (r = -.082). Age was significantly correlated with T1S (r = .250), C7S (r = .244), and △ (r = .112). Among them, △ was stable until 74 years after which it showed an elevation from 3.3° in the group 70-74 years to 4.1° in the group over 75 years. Moreover, there was marked variation between T1S and C7S at 1 lordotic, 2 lordotic, straight and 2 sigmoid alignment patterns, but no difference was seen between T1S and C7S at kyphotic and 1 sigmoid alignment patterns.

CONCLUSIONS

There was a progressive increase in T1S, C7S, and △ with age. Linear regression equations for accurate prediction of T1S were developed based on the C7S in 1 lordotic, 2 lordotic, straight and 2 sigmoid alignment patterns. C7S may be a reliable proxy for T1S in kyphotic and 1 sigmoid alignment patterns.