The Diagnostic Value of Clinical Sacroiliac Joint Pain Provocation Tests for Detection of Sacroiliitis Identified by MRI in Sampled Iraqi Patients with Inflammatory Back Pain.

Background: Sacroiliitis has been considered as the keystone in the diagnosis of axial spondyloarthritis (SPA). The diagnosis can be challenging in early stages of sacroiliitis, as conventional radiographs may be normal. Pain provocative tests can be very helpful to give a clue whether sacroiliitis is present in suspected patient by reproducing the patient's pain. Objective: To assess the validity of clinical sacroiliac joint pain provocation tests for sacroiliitis in comparison with magnetic resonance imaging (MRI). Patients and methods: A total of 65 patients were selected from cohort of patients with persistent inflammatory low back pain during their attendance to the Rheumatology Consultant Clinic at Baghdad Teaching Hospital. Data were collected using questionnaire and interview. Socio-demographic characteristics, disease duration and clinical data were recorded for all patients. Data from four different clinical examination tests (Flexion Abduction and External Rotation [FABER], direct compression, distraction, and lateral compression) with subsequent MRI findings of sacroiliac joint for each patient were analysed. Positive MRI findings were further subdivided into active and chronic lesions according to the new ASAS (association of spondyloarthritis international society) criteria of positive imaging in spondyloarthropathy. Results: A total of 65 patients were included in this study, age range 18-39 years, 69.2% were men. The prevalence of sacroiliitis in the study was 67.7% (43.1% bone marrow oedema, 18.5% erosions, 15.4% sclerosis, 6.2 % for each of effusion; ankyloses and capsulitis). In the whole study group, the highest association with sacroiliitis was for FABER test with sensitivity of 75% while the most specific one was the lateral compression test (71.4%). In men, sacroiliitis was associated with sacroiliac joint (SIJ) clinical tests assessed in multi-test regimens; significant association was found by combining direct compression and FABER test with sensitivity of 51% and specificity of 28.5%. Conclusion: This study identified the reliability of a number of clinical examination tests of SIJ, which increase as they are used in multi-test regimen rather than each one alone, this had a significant association for men only.