SHOULD A MRI FOR BACKPAIN INCLUDE THE SI JOINT?

Abstract

Introduction: Sacroiliac joint pathology can contribute to lowback pain and sciatica. Its frequency and significance is controversial.

Aims: The purpose of this study is to evaluate the incidence and clinical significance of positive SI joint pathology on MRI scans.

Methodology: 353 MRI reports and scans carried out over a one year period for backpain and sciatica were reviewed. Demographic data and clinical notes of patients who had positive SI joint pathology on MRI scans were analysed. Correlation between clinical suspicion of SI joint pathology and MRI findings was studied.

Results: 12 scans showed pathology in the SI joint, an overall incidence of 3.3%.8(66%) were males and 4(33%) females. Only 4(33%) of these patients had Plain Film abnormality. Average age of 41.2 years (33–54). One patient was known case of Ankylosing Spondylitis. Other positive pathology included oedema, sclerois and bridging osteophytes. Clinicians requested inclusion of SI joint in 43 patients. 8 of these were positive, an incidence of 18.6%. In 130 patients, the SI joints were imaged as routine. This yielded positive pathology in 4 patients (3%).

Conclusion: Our study concludes that 18.6% of patients who are suspected to have SI joint involvement clinically have positive pathology on MRI scans.

Routine inclusion of imaging of the SI joint as part of lumbosacral spine MRI for back pain and sciatica shows only 3% positive results.

SI joint should be imaged only if clinically suspected.