Sacroiliac joint pain due to bacterial infection: a report of two cases

Isolated infection of the sacroiliac joint is a rare cause of low back pain. Delayed diagnosis can result in significant morbidity. The diagnosis may be missed initially if physicians do not consider the possibility of infection. The clinical index of suspicion should increase in the presence of certain historical and examination findings. These include intravenous drug use, immunosuppression, recent infection elsewhere, fever and warmth or swelling over the sacroiliac joint. Two cases of sacroiliac joint pain due to Staphylococcus aureus infection are presented, with an overview of the etiology, diagnosis and management of the disorder.