Lumbar facet joint septic arthritis presenting atypically as acute abdomen – A case report and review of the literature

INTRODUCTION: Septic arthritis of the lumbar facet joints is uncommon. The clinical presentation is unusual and patients usually presents with acute back pain or with signs and symptoms mimicking acute abdomen. PRESENTATION OF CASE: A 52 year old man was admitted to the surgical ward with acute onset of abdominal pain and a provisional diagnosis of acute pyelonephritis. After the initial inconclusive investigations, magnetic resonance imaging was highly suggestive of lumbar facet joint septic arthritis. He was treated with intravenous antibiotics with complete resolution of infection. DISCUSSION: The diagnosis of septic arthritis of facet joint is becoming more common with MRI scans. The clinical signs and symptoms are usually difficult to differentiate from acute spondylodiscitis. The commonest organism isolated is Staphylococcus aureus. A prompt and early diagnosis and treatment help to eradicate infection and prevent complications. CONCLUSION: The atypical presentation of facet joint septic arthritis is one of the reasons why early diagnosis is elusive. Definitive diagnoses with MRI and bacterial culture as well as prolonged antibiotic therapy are recommended in this condition.