AB0799 Anatomical abnormalities of the lower lumbar spine do not change the course of non-radiological axial spondyloarthritis

Background Diagnosing early spondyloarthritis (SpA) is crucial for effective therapeutic intervention. Magnetic resonance imaging (MRI) helps us to diagnose non-radiographic SpA (nr-ax SpA) in an stage according the criteria of arm Assessment Spondyloarthritis International Society (ASAS) classification. Diagnosis sacroiliitis using MRI has limitations because lack specificity and sensitivity. Several differential diagnoses are well known should be considered 1 . In our daily practice, anomalies lower lumbar spine sacrum, such as spondylolysis, dysraphia, or assimilation joints, often found accompanied by changes sacroiliac joints (SIG) corresponding sacroiliitis. Objectives To investigate presence anatomical cohort diagnosed nr-ax patients fulfilling ax show if they cause a difference outcome. Methods Patients (n = 56, age < 45 years, symptom duration 3– 24 months) recently with meeting ASAS axial were followed-up 2 years We retrospectively analyzed anatomic on and, available, radiograph images. Results t0 revealed that 15 (26.7%, one female 14 males) 56 had spine, indicating bone marrow edema clinical classification criteria. Spondylolysis, dysraphia 4 (7.1%), 7 (12,5%), (12.5%) patients, respectively. The HLA-B-27 assessment results (CRP-ASDAS BASDAI, BASMI) similar without mentioned anomalies. spondylolysis those displayed progression findings between t2. Conclusion addition well-known noninflammatory causes sacroiliitis, pregnancies intensive sporting activity, peculiarities could not reasons. Contrary latest literature 3 , responsible non-specific No development was observed when compared. References [1]de Winter J, de Hooge M, van Sande et al. Resonance Imaging Sacroiliac Joints Indicating Sacroiliitis According SpondyloArthritis international Definition Healthy Individuals, Runners, Women With Postpartum Back Pain. Arthritis Rheumatol. 2018 Jul; 70 (7):1042-1048. [2]SpA.47 (DGRH Congress 2021 virtuell Posterwalk) Is course newly more aggressive than previously thought? Becker-Capeller,D [3]Campos-Correia, D., Sudoł-Szopińska, I., & Diana Afonso, P. Are we overcalling MRI? Differential diagnosis every rheumatologist know - Part I. Acta reumatologica portuguesa 2019, 44(1), 29–41. Disclosure Interests Detlef Becker-Capeller Grant/research support from: Research Novartis, Smaragda Kapsimalakou: None declared