[Factitious disorder revealed by polymicrobial septic arthritis of a lumbar facet joint diagnosed by percutaneous biopsy].

Septic arthritis of a lumbar facet joint is rare with few reports in the literature. Clinically, septic arthritis of a lumbar facet joint can mimic spondylodiscitis. Imaging is usually required for diagnosis. Bacteriological diagnosis is needed to optimize treatment with antibiotics. Most of the previously reported cases were due to staphylococcus aureus. We report one case due to rare bacteria which lead to a diagnosis of factitious disorder. Precise bacteriological diagnosis was obtained by CT-guided percutaneous biopsy.