長期にわたり持続した人工膝関節再置換術後感染に対し再々置換術を行った一例

抄録

We report on a patient who underwent repeated total knee arthroplasty (TKA) due to an infection that persisted for more than 8 years. A 69-year-old man with rheumatoid arthritis diagnosed in 1987 underwent TKA of the left knee in July 1998. The implant gradually loosened over the following year with possible infection. In March 2000, one-stage TKA was performed again using bone cement containing vancomycin. Purulent discharge occurred 2 weeks after the second TKA. After a more than 8-year course of persistent chronic osteomyelitis, the implant was removed (Neisseria elongata subspecies nitroreducens was isolated by intraoperative culture) and replaced with cement beads containing gentamicin on March 11, 2009. A third TKA and allogeneic bone transplantation were performed 10 weeks later. At 1 year and 7 months after the third TKA, no relapse of infection or loosening of the artificial joint has occurred. Suppression of the infection was possible because the causative bacterium was not antibiotic resistant, the affected area was completely curetted, the third TKA was performed at an appropriate interval after the second TKA, all cultures became negative before the third TKA, and the wound was completely closed to assure that dissolution of the antibiotic from the cement beads would be confined to the affected area.