Lumbar spine facet joint septic arthritis: Two case reports

Introduction: Septic arthritis of the facet joint (SAFJ) is a rare spine condition. Commonly seen in older immune-compromised patients presented with acute back pain, it needs early diagnosis and intervention. Case Series: We report two cases presented to the emergency as acute onset low back pain with fever and high inflammatory markers. In both cases, patients were admitted and diagnosed with septic arthritis of the facet joint and associated epidural abscess. In the first case, blood cultures were sent to support the diagnosis, while in the second case ultrasound-guided aspiration was done. In both cases, cultures were positive for Methicillin-resistant Staphylococcus aureus (MRSA) and diagnosis confirmed with magnetic resonance imaging (MRI) findings. Both patients were treated with intravenous antibiotics and improved clinically. Conclusion: This case shows the importance of thinking about septic arthritis in the facet joint in older patients who present with sudden onset back pain associated with high inflammatory markers if other differentials are excluded. Magnetic resonance imaging is considered the imaging modality of choice in the diagnosis. As well, early diagnosis and management play an important role to prevent complications.