A New Global Spinal Balance Classification Based on Individual Pelvic Anatomical Measurements in Patients With Adult Spinal Deformity.

Abstract

A retrospective study. This study aims to establish a new, easy-to-implement global spinal balance (GSB) classification based on individual pelvic anatomical measurements in adult spinal deformity patients, and to validate this classification in terms of patients' quality of life (QOL). Coronal (central sacral vertical line) and sagittal (C7 sagittal vertical axis [C7 SVA]) lines are standard parameters to evaluate GSB. However, these parameters do not consider individual differences in height and physique. Therefore, a new classification to more simply evaluate GSB related to QOL would be a beneficial tool. This study included 279 patients with adult spinal deformity. The enrollment criteria included age >18 years and scoliosis >30°. GSB was evaluated based on C7 coronal vertical axis and C7 SVA, and was graded with our sagittal (Grades 1-3) and coronal classifications (Grades 1-3), where larger values represented worse GSB. In addition, total global balance classification (Grades 1-3) was also established based on both coronal and sagittal classifications. Patient self-assessment measures of health status were collected using the Scoliosis Research Society patient questionnaire (SRS-22). The relationships between responses to the SRS-22 and GSB were evaluated using partial correlation coefficients, adjusted by age. A newly described coronal classification correlated with the preoperative function (P < 0.02), pain (P = 0.001), subtotal (P < 0.001) domains in the SRS-22, whereas a newly described sagittal classification was correlated with the preoperative subtotal domain (P < 0.001). There were also significant correlations between total global balance and the preoperative function (P = 0.03) and subtotal domains (P < 0.001) in the SRS-22. We present a simple new classification for GSB that strongly correlates with QOL in patients with adult spinal deformity, thereby translating clinical data into meaningful patient outcomes and livelihoods.Level of Evidence: 4.