All that glitters is not gold: sacroiliitis.

OBJECTIVES

The aim of this study was to determine the prevalence of "rheumatic" and "non-rheumatic" changes of the sacro-iliac joints (SIJ).

MATERIAL AND

METHODS

We performed MRI in 210 patients with suspected inflammatory low back pain. We sorted and analysed the characteristics of sacroiliac bone lesions in "rheumatic" and "non-rheumatic" patients and assessed the diagnostic values of their extent and location. SIJ lesions were classified on the basis of their location into two categories: unilateral and bilateral. Their extent was then measured and assigned to one of two groups: <1 cm or ≥ 1 cm.

RESULTS

In 45 cases (21%), the MRI findings matched the clinical diagnosis of "rheumatic" sacroiliitis. Interestingly, in 99 cases (47%) the SIJ changes were classified as "non-rheumatic". L5-S1 degenerative changes, scoliosis and pelvic asymmetry were most frequently encountered as concomitant phenomena in our study.

CONCLUSIONS

MRI of the sacroiliac joints in patients suspected of inflammatory low back pain demonstrated more often "non-rheumatic" changes.