Septic arthritis of unilateral lumbar facet joint with contiguous abscess, without prior intervention.

A 40-year-old female patient presented with persistent severe back pain radiating to the right leg, abdominal pain and constipation. Other clinical symptoms included nausea, vomiting and high-grade fever. Clinical examination showed generalised abdominal and lower back tenderness. There was no sensory loss or motor weakness in lower limbs, however investigations showed raised inflammatory markers. Radiographs of the lumbar spine and hip joint were normal. MRI revealed a septic arthritis of the right L3/4 facet joint, associated with a large abscess extending anteriorly to the right paraspinal muscles and posteriorly into the right posterolateral aspect of the epidural space in the central spinal canal, with moderate compression of the dural sac. Unlike any other reported similar case, this septic arthritis developed without prior medical intervention. The patient was treated successfully with ultrasound guided drainage of the facet joint/abscess and antibiotics.