Septic arthritis of the lumbar facet joint presenting as spontaneous bacterial peritonitis: a rare case requiring surgical intervention.

Abstract

To report and discuss a rare case of septic arthritis of a lumbar facet joint presenting as septic bacterial peritonitis and requiring surgical debridement. A 55-year-old man, with a history of intravenous drug usage and hepatitis C, presented to the emergency department with fever, abdominal and lumbar pain. Examination showed ascites. Erythrocyte sedimentation rate and C-reactive protein were elevated. A paracentesis was performed, and a diagnosis of spontaneous bacterial peritonitis was assumed as acute on chronic liver failure. The patient was admitted for antibiotic treatment with cefotaxime. Staphylococcus aureus was isolated in blood cultures. Despite directed treatment, there were persistent fever, back pain and continuous elevation of serum inflammatory markers. An MRI of the lumbar spine was performed 14 days after presentation and identified septic arthritis of the left L4-L5 facet joint. In the absence of a response to the medical treatment, surgical debridement of the facet joint was performed. After surgery, back pain resolved and inflammatory markers started to decline. One year after surgery, the patient is asymptomatic and has normalization of the inflammatory markers of infection. Follow-up MRI shows complete resolution of the infection. Septic arthritis of the lumbar facet joints is a rare condition with no more than 50 cases reported in the literature. This infection, which can cause significant morbidity, can result from local or systemic inoculation. MRI is the diagnostic method of choice. While antibiotic therapy is the first line of treatment, when it fails, surgical debridement may be necessary.