The association between sonographic enthesitis and radiographic damage in psoriatic arthritis

BACKGROUND To examine the association between sonographic enthesitis and the severity of radiographic features of damage in the peripheral and axial joints in psoriatic arthritis (PsA). METHODS A cross-sectional analysis was conducted in patients with PsA. The MAdrid Sonography Enthesitis Index (MASEI) scoring system was used to quantify the extent of sonographic entheseal abnormalities. Radiographic damage in the peripheral joints and spine was assessed by the modified Steinbrocker score (mSS), Modified New York Criteria for sacroiliitis, and the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS). The association between MASEI and the extent of radiographic damage was assessed using negative binomial and logistic regression. The results were expressed in terms of the regression coefficient estimates and their exponentiated values (eβ) or odds ratios (OR), and 95% confidence intervals (CI). RESULTS Two hundred and twenty three patients were analyzed; 58% were males, with mean ± SD age of 55.9 ± 12.9 years and PsA duration of 16.7 ± 12.4 years. Regression analyses yielded an association between higher MASEI scores (10 units increase) and peripheral joint damage including mSS (eβ = 1.42, 95% CI: 1.15, 1.72), joint ankylosis (OR = 1.93, 95% CI: 1.37, 2.72), arthritis mutilans (OR = 1.77, 95% CI: 1.23, 2.54), and periostitis (OR = 1.41, 95% CI: 1.08, 1.84). Similarly, an association was found between higher MASEI scores and axial damage as measured by mSASSS (eβ = 2.18, 95% CI: 1.16, 4.09) and sacroiliitis (OR = 1.33, 95% CI: 1.03, 1.72). CONCLUSIONS The severity of sonographic enthesitis is a potential marker of radiographic peripheral and axial joint damage in PsA.