Pyogenic arthritis of a lumbar facet joint.

We herein report the case of a 68-year-old man with diabetes who developed pyogenic arthritis of a lumbar facet joint after spinal injection. We performed magnetic resonance imaging (MRI), computed tomography (CT), technetium 99 methylene diphosphonate scintigraphy, and single photon emission computed tomography (SPECT) for this patient. MRI showed a lesion in the facet joint and no evidence of spondylodiscitis. CT showed a swelling of periarticular soft tissue around the facet joint. Bone scintigraphy showed a characteristic vertical uptake. In particular, SPECT was able to clearly confirm the location of the infection. An infection of the facet joint has only been rarely reported, but we recommended that this area should be carefully evaluated whenever a patient develops an infection of the lumbar spine after a spinal injection.