AB0509 FREQUENCY AND RISK FACTORS OF HIP INVOLVEMENT DURING SPONDYLOARTHRITIS IN MILITARY PATIENTS
Authors: L. Kharrat, M. Slouma, S. Rahmouni, R. Dhahri, I. Gharsallah, L. Metoui, B. Louzir
Journal: Annals of the Rheumatic Diseases (2021)

Background: Hip involvement can reveal a spondyloarthritis (SA) or appear later. It hampers patient’s life quality and can be responsible of significant handicap (1). Military patients are a special population. They are more exposed to physical stress which makes their SA characteristics quite different to other patients. Objectives: We aimed to determine the frequency of hip involvement in SA and to study its characteristics and associated factors in military patients. Methods: We conducted a cross-sectional study carried out in Rheumatology department of Military Hospital of Instruction of Tunis over a 10-year period (2010-2020) including SA patients meeting The Assessment of SpondyloArthritis international Society (ASAS). For each patient we collected the following informations: age, characteristics of hip involvement, ASDAS (Ankylosing Spondylitis Disease Activity Score), BASDAI (Bath Ankylosing Spondylitis Disease Activity Index), BASMI (Bath Ankylosing Spondylitis Metrology Index) and BASRI (Bath Ankylosing Spondylitis Radiology Index). We also measured Erythrocyte Sedimentation rate (ESR) and C-reactive protein (CRP). Results: One hundred forty-one patients were included. They were 103 men and 38 women. The mean age was 43.01± 12.9 years. The mean age at the onset was 34.28±12.05 years. The mean delay of the disease was 9.16±8.98 years. The mean BASDAI and l’ASDAS-CRP were 3.89±2.29 and 3.07±1.83, respectively. Hip involvement was noted in 35.5% of the cases (n=50). It was bilateral in 41 of the cases. The number of affected hips was thus 91. The mean delay between the onset of SA and the discovery of hip involvement was 32.24±53.58 months [0-264 months]. A significant difference was noted in the axial mobility between patients who have hip involvement and those who don’t (BASMI was 3,8±2.45 versus 1,45±1.8, p&lt;0.0001). Moreover, functional impact was higher in patients with hip involvement (BASFI was 5.7±2.24 versus 3.45±2.86, p&lt;0.0001). Patients with hip involvement had significantly higher BASRI compared to patients with no hip involvement (5.79±3.17 versus 3.14±2.42, p&lt;0.0001). However, no difference was found between patients who have hip involvement and those who don’t with these following parameters: ESR, CRP, BASDAI and ASDAS-CRP. Conclusion: Our study showed that hip involvement is quite common in military SA patients. It is responsible of an important functional impact and it seems to be associated to a major limitation of axial mobility. Nevertheless, hip involvement was not associated neither to inflammation parameters levels nor to the disease activity, this suggest that hip involvement may progress independently of the disease activity in military patients due to physical stress and micro traumas. References: [1]López-Medina C, Castro-Villegas MC, Collantes-Estévez E. Hip and Shoulder Involvement and Their Management in Axial Spondyloarthritis: a Current Review. Curr Rheumatol Rep. sept 2020;22(9):53. Disclosure of Interests: None declared.