Study design: A retrospective study.
Objective: The aim of this study is to investigate the changes in sleep quality in patients surgically treated for kyphosis due to ankylosing spondylitis (AS) and the correlation between these changes and spinal sagittal realignment.
Summary of background data: Sleep problems are prevalent in AS patients. However, little attention has been paid to the sleep quality in patients with AS kyphosis and the effect of surgical intervention on sleep quality.
Methods: We have retrospectively reviewed 62 patients with AS-induced thoracolumbar kyphosis who underwent surgically treatment from October 2012 to November 2016. Sleep quality was evaluated by the Pittsburgh Sleep Quality Index (PSQI) questionnaire. Preoperative and postoperative radiological characteristics and supine function were documented. We compared the above-mentioned parameters pre- and 24 months postoperatively and analyzed the correlation of the changes in the PSQI with the changes in radiological characteristics.
Results: Fifity-one patients (82%) classified as poor sleepers preoperatively. In addition to use of sleeping medication, each domain of the PSQI and the total PSQI were increased postoperatively. Improved sleep quality was correlated with changes in spinal sagittal characteristics, among which the lumbar lordosis (LL) and the chin-brow vertical angle (CBVA) were the independent correlation factors. The number of patients with supine dysfunction decreased from 89% to 15% after surgery. Significant differences were identified in the PSQI scores between the patients with and without supine dysfunction either pre- or postoperatively.
Conclusion: Surgical correction of spinal deformity may improve sleep quality and supine function in patients with AS. Spinal sagittal realignment may be correlated with the improvement of sleep quality.
Level of evidence: 4.