Sagittal Parameters of Spine and Pelvis in Young Adults Using the EOS Imaging System: Prospective Study of 92 Asymptomatic Subjects

Abstract

Study Design: This study adopted a prospective study design to evaluate the sagittal parameters of the spine and pelvis in young adults using the EOS imaging system.Purpose: This study was designed to analyze spinopelvic sagittal alignment measurement values obtained using the EOS imaging system in asymptomatic young adults.Overview of Literature: Sagittal alignment of the spine and pelvis is important in diagnosing and treating spinal diseases. We usually take sagittal images using whole-spine standing lateral radiography. Recently, the EOS imaging system, which uses a low-dose radiation in a weight-bearing state, was developed. So, we studied the sagittal parameters of the spine and pelvis in young adults by using the EOS imaging system.Methods: We recruited young adults aged 20–30 years and explained the EOS imaging system. They voluntarily participated in the study. We took full-body standing orthogonal anteroposterior and lateral images using the EOS imaging system (EOS imaging, Paris, France). Then, we measured the pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT), sagittal vertical axis (SVA), T1/T12 kyphosis, and L1/S1 lordosis. We analyzed each parameter using Student <i>t</i>-test, paired t-test, and Pearson’s correlation coefficient.Results: Ninety-two patients were enrolled in the study. The average PI and SS were 47.18° and 36.03°, respectively. Moreover, PT and SVA were 11.17° and -10.15 mm, respectively. T1/T12 kyphosis was 37.37°, while L1/S1 lordosis was 46.64°. All parameters were enough for normal distribution. Pearson correlation coefficient analysis showed a meaningful correlation between PI and SS and PI and PT (<i>R</i>>0.6, <i>p</i><0.05).Conclusions: Measuring spinal and pelvic sagittal values is important. Sagittal parameters could help decide how to operate patients with spinal diseases. We attempted to obtain sagittal values using the EOS imaging system. These parameters could help preoperatively estimate the lumbar lordosis restoration and could also be used as guidelines for spinopelvic sagittal balance.