ABSTRACT

Objectives:

Sagittal deformity requires higher energy to maintain an erect posture. Clinically, to be able to assess the severity of sagittal deformity and efficacy of compensatory mechanisms, new parameters are required. This study investigated the correlation between clinical relevance of global sagittal axis (GSA) and the severity of sagittal deformity.

Methods:

In this study, retrospective review of patients who underwent fullbody radiographs and clinical scoring systems which are Oswestry Disability Index (ODI), Scoliosis Research Society–22 and the visual analog scale for back and leg pain are integrated. The GSA is the angle between a line from the center of C-7 to midpoint of the femoral condyles, and a line from the posterior superior corner of the S-1 sacral endplate to midpoint between the femoral condyles. Correlation between clinical scoring systems and GSA data were compared.

Results:

Eighty-four patients (mean age 46 years) were included. The GSA correlated significantly with all ODI, Scoliosis Research Society–22 and the visual analog scale for back and leg pain scores. Statistical analysis revealed that in sagittal deformity, the GSA increased with a concurrent increase in pelvic posterior translation (+0.186) and knee flexion (+0.284) and decrease in pelvic retroversion (-0.832)

Conclusions:

The GSA is a practical and reliable measure to assess the sagittal deformity.The GSA correlated highly with clinical scores.