Spinal osteotomy in ankylosing spondylitis: radiological, clinical, and psychological results

Abstract

Background context: Little is known about the psychological status in patients with ankylosing spondylitis (AS) before and after correction of fixed sagittal imbalance.

Purpose: The aim of this study was to evaluate the changes in patients' psychological status after surgical correction and the existence of a correlation between psychological state and the angle of correction.

Study design: A retrospective study was performed to assess radiological and clinical results, and psychological status in patients with AS with fixed kyphotic deformity.

Patient sample: The sample comprises 24 patients with AS with fixed sagittal imbalance who underwent one-stage corrective osteotomies at our hospital between March 2006 and May 2010. All of the patients included in this study demonstrated an inability to look straight forward because of severe kyphotic deformities.

Outcome measure: The radiologic analysis included evaluation of thoracic kyphosis, lumbar lordosis, and the sagittal vertical axis (SVA) of the spine. Clinical assessments were performed with Short Form 36 (SF-36), the Bath Ankylosing Spondylitis Function Index (BASFI), and the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). Patient psychological status was assessed using the Hospital Anxiety and Depression Questionnaire (HADS) and the Health Locus of Control-Form C Questionnaire (HLC-C).

Methods: Each of the above measurements was recorded before and 1 year after the surgery. The changes derived from each measurement before and after the surgery were evaluated. We also analyze the correlations among the radiological, clinical, psychological, and mental evaluations.

Results: Mean thoracic kyphosis changed from 38.5° to 33.3°. Mean lumbar lordosis was corrected from 13.8° to 26.1°, and the SVA was improved from 110.8 mm to 49.7 mm. There was significant improvement in the SF-36, BASDAI, BASFI, HADS, and HLC-C scores. The SVA changes were closely linked to BASFI and psychological status, especially anxiety and depression.

Conclusions: The scores of disease status, general health, and psychological status were improved significantly after correction of kyphotic deformity. And the correction of sagittal imbalance was correlated significantly with anxiety and depression.

Keywords: Ankylosing spondylitis; Corrective osteotomy; Kyphotic deformity; Pedicle subtraction osteotomy; Psychological status; Smith-Petersen osteotomy.