Prevotella osteomyelitis after dental capping procedure

We present a 49 year old man who presented to the emergency department with severe lower back pain of 5 days duration. One week prior he had been diagnosed with a right psoas muscle abscess and was discharged with a 28 day course of moxifloxacin after the preliminary culture from the psoas grew an anaerobic organism. MRI of the lumbar spine showed marrow edema in the L2 body, occupying most of the anterior two thirds of the body, with cortical erosion at the anteroinferior aspect of L1. Blood cultures were negative and bone biopsy of L2 showed neutrophilic invasion and reactive changes. Cultures grew Prevotella oralis. Hematogenous spread from a composite bonding procedure for exposed teeth roots is thought to be the source for the vertebral osteomyelitis. This is a plausible spread of infection in our case because it was thought that the osteomyelitis occurred first and spread to the psoas muscle.