AB0842 Foot entheses ultrasound in spondyloarthritis: a case control study

BackgroundFoot entheses involvement is a common manifestation of spondyloarthritis (SpA). It can be responsible for functional impairment. The superiority of ultrasound (US) examination in foot entheses damages detection has been reported [1].ObjectivesWe aimed to compare the US findings of foot entheses between SpA patients and asymptomatic healthy control subjects.MethodsWe conducted a cross-sectional study including 37 SpA patients (G1) fulfilling ASAS criteria for Axial SpA and 37 healthy subjects (G0) matched by age and gender. Demographic and clinical characteristics were collected. A blind US of foot entheses was performed by Mindray DC-70 equipment with a 6-16 MHz linear probe. Calcaneal enthesis (CT) and plantar fascia (PF) were examined bilaterally. A total of 296 entheses were assessed.In G1, disease activity was evaluated using the Bath Ankylosing Spondylitis Activity Index (BASDAI) and the Ankylosing Spondylitis Disease Activity Score (ASDAS).Statistical Package for Social Sciences (SPSS) was used for analysis.ResultsThe study included 58 men and 16 women. The mean age was 44.6 ± 12.3 years. In G1, the mean disease duration was 108.2±94 months. The average BASDAI was 4.5±2.2. The average ASDASCRP was 3.2±1.3. In G1, clinical examination showed tenderness at the posterior insertion of the CT or inferior insertion of PF in 16.2% of patients.However, US lesions of the CT were found in 97% of cases in G1 and 67.6% in G0, p:0.001. US lesions are presented in Table 1.Table 1.Elementary US lesions in SpA and healthy control groupsEnthesisG1 (n (%))G0 (n (%))pCalcaneal tendonThickness15 (40.5)6 (16.2)0.02Erosion9 (24.3)1 (2.7)0.007Enthesophyte29 (78.4)20 (54)0.03Calcification14 (37.8)10 (27)0.32Bursitis4 (10.8)3 (8.1)1PD signal10 (27)00.001Plantar fasciaThickness30 (81.1)27 (73)0.4Erosion11 (30)1 (3)0.002Enthesophyte12 (32.4)2 (5.4)0.003Calcification18 (48.6)6 (16.2)0.003PD signal11 (30)0G0: control group, G1: Spondyloarthritis group, PD: power dopplerCalcaneal tendon thickness was noted in 40.5% in G1 and 16.2% in G2 (p=0.02). Hypo-echogenicity and loss of normal fibrillar structure were more frequent in G1 (86.5% versus 29.7%, pVascularity at power Doppler was significantly more frequent in G1 (p=0.001 in CT and pIn G1, the disease activity was higher in patients with structural damage lesions of the CT (ASDAS CRP: 3.2 versus 1.9; p=0.01). However, there was no associations between vascularity at power Doppler and high disease activity (p=0.47).ConclusionOur study showed that the US lesions of the heel entheses were frequent in SpA patients compared to healthy control. Moreover, US can reveal enthesitis even in asymptomatic patients.The disease activity was higher in patients with US structural damage lesions of the CT.References[1]De Miguel E, Cobo T, Muñoz-Fernández S, Naredo E, Usón J, Acebes JC, et al. Validity of enthesis ultrasound assessment in spondyloarthropathy. Ann Rheum Dis. 2009; 68(2):169-74.Disclosure of InterestsNone declared