Listeria monocytogenes septic arthritis following intra-articular yttrium-90 therapy.

Listeria monocytogenes is a rare cause of septic arthritis, which usually occurs in a host compromised by systemic illness. Intra-articular irradiation with yttrium-90 is generally free of complication. We report a case of intra-articular sepsis of the knee joint by Listeria monocytogenes acquired under unusual circumstances.