Dano estrutural em coluna e capacidade funcional nos pacientes com espondiloartrite axial

Abstract

Objective To investigate the relationship between structural damage of the spine and functional capacity in patients with axial spondyloarthritis (axSpA) and to compare the strength of the association of two radiographic scores [modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) and Combined Ankylosing Spondylitis Spine Score (CASSS)] with the clinical variable mentioned above. Methods Radiographs from 101 consecutive axSpA patients were scored by three readers according to the method of de Vlam et al. for cervical facet joints (CFJ) and according to the mSASSS for vertebral bodies. CASSS was calculated as the sum of both scores. Physical function was assessed by the Bath Ankylosing Spondylitis Functional Index (BASFI), disease activity by the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and the Ankylosing Spondylitis Disease Activity Score (ASDAS), mobility by the Bath Ankylosing Spondylitis Metrology Index (BASMI) and quality of life by the Ankylosing Spondylitis Quality of Life (ASQOL). Correlations between clinical parameters and radiographic scores were analyzed by Spearman’s test. Univariate and multivariate analyses were performed to investigate the association between outcomes and possible explanatory variables. Contributory effects of age, sex, symptoms duration, smoking and history of total hip arthroplasty (THA) were also explored in the multivariate linear regression models. Results BASFI correlated strongly with ASQoL (Spearman’s rho = 0.655; p < 0.001) and BASDAI (Spearman’s rho = 0.699; p < 0.001), moderately with BASMI (Spearman’s rho = 0.457; p < 0.001) and ASDAS (Spearman’s rho = 0.586; p < 0.001) and weakly with mSASSS (Spearman’s rho = 0.285; p = 0.004) and CASSS (Spearman’s rho = 0.275; p = 0.005). A best-fit multivariate model for BASFI, adjusted for symptoms duration, age, sex and smoking status, included BASDAI (B = 0.761; p < 0.001), BASMI (B = 0.617; p < 0.001) and THA (B = 1.218; p = 0.050). Radiographic scores were predictors of the BASFI only when BASMI was removed from the model: mSASSS (B = 0.026; p = 0.012) and CASSS (B = 0.024; p = 0.005). Conclusion In the present study, spinal damage was independently associated with physical function in axSpA but to a lesser extent than disease activity and mobility. Moreover, incorporating cervical facet joints assessment in the mSASSS did not increase its strength in predicting function