Spinal sagittal balance associated with age, vertebral fracture, and functional disability in patients with rheumatoid arthritis: A cross-sectional study

Abstract

Abstract Objectives: The purpose of this study was to assess the relationships between spinal sagittal balance and functional ability of Japanese patients with rheumatoid arthritis. Methods: A total of 491 patients with rheumatoid arthritis who underwent the measurement of sagittal vertical axis for the assessment of spinal sagittal balance were enrolled. Factors associated with sagittal vertical axis were analyzed by categorizing patients according to sagittal vertical axis (<4\u2009cm, 4–9.5\u2009cm, and >9.5\u2009cm). In addition, univariate and multivariate regression analysis were performed to identify factors associated with Health Assessment Questionnaire Disability Index (HAQ-DI) in different age groups. Results: The percentage of patients with sagittal vertical axis <4\u2009cm, 4–9.5\u2009cm, and >9.5\u2009cm was 61.1%, 32.4%, and 6.5%, respectively. Age, vertebral fracture, and gait speed were associated with sagittal vertical axis. Sagittal vertical axis was associated with HAQ-DI in the 80–90 years age group. Conclusion: Sagittal balance was associated with age, vertebral fracture, and gait speed. In super-aged patients with rheumatoid arthritis, HAQ-DI was affected by sagittal balance. Management of super-aged patients with rheumatoid arthritis should include evaluation of joints as well as spinal alignment.