1067 Prevalence of SIJ Pathology: A Retrospective Observational Study

Abstract Aim Sacroiliac joint (SIJ) pathology is often said to be an underdiagnosed cause for lower back pain (LBP), with the literature suggesting a point prevalence of 25%. However, there is limited published evidence to support the true prevalence of SIJ pathology. This single-centred retrospective observational study aims to produce evidence on the prevalence of SIJ pathology detected through imaging. Method Patients presenting with LBP at a single spinal surgeon clinic from 2014 to 2022 were identified. Among them, patients who underwent SIJ imaging were selected. Their baseline characteristics, medical history, risk factors, examination findings, and imaging results were collected and analysed. Results A total of 969 patients were found to have presented with lower back problems. Within this group, 265 patients went on to have SIJ imaging, and 31 patients were found to have pathological SIJ. This suggests a pathological SIJ prevalence of 3.2% amongst patients presenting with LBP (31 out of 969 patients). A medical history of previous spinal surgery showed a strong correlation with degenerative SIJ (p=0.0049). Other known risk factors were not found to have a statistically significant correlation with the incidence of SIJ pathology. Examination findings of pain provocation tests, when used in combination, suggest a high specificity score. Conclusions The low prevalence rate from this study might suggest a lower index of suspicion for SIJ pathology. The real prevalence of SIJ pathology remains inconclusive. Further meta-analysis is required to understand the true prevalence rate of SIJ pathology.