Is there a direct correlation between cervical sagittal alignment and spinopelvic sagittal alignment?: an observational study from asymptomatic Indian adults.

Study design: Observational study.

Purpose: Cervical parameters play a vital role in maintaining global spinal sagittal alignment, but their correlation with spinopelvic parameters remains unclear. This study aimed to investigate potential direct correlations between cervical sagittal alignment and spinopelvic alignment in an asymptomatic population.

Overview of literature: Previous studies have demonstrated a direct relationship between pelvic parameters, lumbar lordosis (LL), and thoracic kyphosis (TK), as well as a direct correlation between cervical lordosis (CL) and TK. However, the direct influence of pelvic parameters and LL on cervical parameters remains unclear, warranting further research.

Methods: This study involved 104 asymptomatic adults (females 62 [59.6%]) aged 18-50 years. Whole-spine standing lateral radiographs were obtained, and the pelvic, lumbar, thoracic, cervicothoracic, and cervical parameters were studied. Pearson's correlation coefficient was used to assess correlations, with a significance threshold of p<0.05.

Results: The mean age of participants was 38.27±9.93 years. The pelvic incidence (PI) significantly correlated with C7 slope (r=-0.212, p=0.05). The pelvic tilt (PT) exhibited significant correlations with T1 slope-CL mismatch (r=-0.229, p=0.05) and C2 slope (r=-0.202, p=0.05). Furthermore, PI-LL mismatch showed a significant correlation with TIA (r=-0.197, p=0.05), T1 slope (r=-0.228, p=0.05), and C7 slope (r=-0.251, p=0.05).

Conclusions: This study reveals a significant correlation between cervical and spinopelvic parameters, emphasizing the interconnectedness of pelvic, lumbar, thoracic, and cervical spine parameters.