[Listeria infection of a prosthetic hip joint]

A 74-year-old male with type 2 diabetes, coronary artery disease with history of CABG, hypertension and chronic obstructive pulmonary disease had total left hip replacement in another medical facility five years prior to admission. Since the early postoperative period, he had manifestations of dormant infection and was with empirical antibiotics. On the index admission, his X-ray showed signs of loosening of the prosthetic components with resorption of the bone. Periprosthetic infection was managed by a two-stage surgery. First, the infected prosthesis was removed and replaced with a spacer with antibiotics. One month later, a revision prosthesis, was implanted using cement with antibiotics. Cultures of the excised tissues and materials yielded massive growth of Listeria monocytogenes and scarce growth of Staphylococcus epidermidis. This is the 18th published case of arthroplasty infection caused by Listeria. The presented patient most likely had dormant staphylococcal infection on which Listeria superinfection developed and accelerated the loosening. A literature review suggested several mechanisms that can make conservative management of Listeria infection difficult. They include marked stimulation of the immune system (with resulting resorption of the bone), survival in the macrophages (unavailability to antibiotics susceptible in vitro) and capability to form biofilm as well as settle in biofilms produced by other organisms. Better yield and reliability of microbiological investigations may be achieved by guided intrarticular fluid aspiration from a microincision, prolonged culture and sonification of the extracted material, two-step surgical management and follow-up intraarticular fluid aspiration prior to reimplantation of revision prosthesis.