Abstract
INTRODUCTION: Septic arthritis of a facet joint (SAFJ) is a rare entity and frequently underdiagnosed. It is most frequently localised in the lumbar segment. CASE PRESENTATION: A 48-year-old woman presented at our emergency room with a chief complaint of lumbar pain and perineal hypoesthesia. An urgent lumbar Magnetic Resonance Imaging (MRI) was performed showing no signs of compressive pathology. Intravenous painkillers were administered improving her clinical symptoms, so she was discharged from the emergency department to be followed at our out-patient clinic. After 12 h, the patient presented again referring an acute loss of strength in her lower limbs and paresthesias at a T10 sensitive level. Due to the severity of the symptoms, we performed an urgent dorsal MRI that showed a septic arthritis of the left T8-T9 facet joint and an epidural abscess causing a medullar compression. Blood cultures were performed before surgical treatment. An urgent laminectomy of T8 and debridement of the abscess were performed. Intraoperative microbiology and blood cultures were positive for Streptococcus constellatus. After surgery, the patient presented a progressive improvement of her symptomatology. DISCUSSION: Physicians should have in mind and rule out this clinical entity to avoid severe consequences that a misdiagnosed SAFJ could develop.