Radiological outcome in ankylosing spondylitis: use of the Stoke Ankylosing Spondylitis Spine Score (SASSS)

We investigated the role of the Stoke Ankylosing Spondylitis Spine Score (SASSS) in a longitudinal cohort study of 53 patients with AS, assessed 9 yr apart, and its relation to clinical, functional and laboratory measures of disease activity and outcome. We also examined the long-term predictive value of quantitative sacroiliac scintigraphy (QSS). SASSS correlated closely with clinical measures, including occiput-wall distance (OWD) (P < 0.001) and modified Schober (P < 0.001). QSS was significantly correlated with final X-ray score (P < 0.05). SASSS changed significantly (P < 0.001) over the study period; two patterns of change in spine score were discernible, one with little change in radiological score and the other showing marked progression. The SASSS is a useful, valid score, which correlates with clinical outcomes measures and which has identified specific patterns of radiographic progression in AS.