SEPTIC ARTHRITIS OF LUMBAR FACET JOINT - ABOUT 3 CASES

Septic arthritis of spinal apophyseal joint, seldom described, mainly concern the lumbar spine. We report three cases. Inflammatory lesions of the paravertebral soft tissues were associated in each case; an epi dural abcess was present twice. Our three cases were due to Staphyloco ccus aureus. The initial clinical features were consistent with a spon dylodiscitis. Imaging led to the correct diagnosis in all cases. Accor ding to our observations and several others of the literature: facet j oint lesions are visible too late on plain films. none scintigraphy is sensitive, but not specific. CT scan and MRI are the most contributiv e investigations. A pathologic aspect of the paravertebral soft tissue s is visible less than one week after the beginning of the symptoms on CT scan and MRI. Lesions of the facet joint are detectable as soon as the first week on MRI, and after 15 days of clinical course on CT sca n. Epidural abcess, when present, is best shown by MRI as early as the first week. CT scan can guide percutaneus needle biopsies of the para vertebral abcesses or of the concerned facet joint.