Relationship between cervical sagittal alignment and quality of life in ankylosing spondylitis

Little information is available on the relationship between cervical sagittal alignment and health-related quality of life (HRQOL) in ankylosing spondylitis (AS) patients. The aim of this study was to identify relationships between cervical sagittal alignment and HRQOL in AS.

The study and control groups comprised 102 AS patients (15 women and 87 men) and age- and sex-matched 50 controls, respectively. All underwent anteroposterior and lateral radiographs and completed clinical questionnaires. The radiographic parameters examined were C2-C7 lordosis, C2-C7 sagittal vertical axis (SVA), T1 slope and T1 slope minus C2-C7 lordosis (TS-CL). A visual analogue scale (VAS 0-10) score for neck pain, the neck disability index (NDI), neck pain and disability (NPAD) scale and bath ankylosing spondylitis disease activity index (BASDAI) were administered to evaluate QOL. Statistical analysis was performed to determine the significances of differences between the study and control groups. In addition, correlations between radiological parameters and clinical questionnaires were sought.

AS patients and controls were found to be different significantly in terms of C2-C7 SVA, T1 slope, and TS-CL. However, no significant intergroup difference was observed for C2-C7 lordosis (P > 0.05). Correlation analysis revealed significant relationships between radiographic parameters and QOL. Multiple regression analysis was performed to identify predictors of QOL, and the results obtained revealed that C2-C7 SVA significantly predicted VAS, NDI, and NPAD scores and that age predicted NPAD score.

Cervical sagittal parameters were found to be significantly different in AS patients and normal controls. Correlation analysis revealed significant relationships between radiographic parameters and QOL. In particular, C2-C7 SVA was found to be a significant predictor of QOL in AS patient.