Borrelia burgdorferi-A Bacterium Worthy of Consideration in Culture-Negative Prosthetic Joint Infection.

A 68-year-old woman presented to the orthopaedic office with 2 weeks of atraumatic right prosthetic knee pain and swelling. She previously lived pain free and fully functional after a total knee arthroplasty 8 years ago. Initial radiographs showed a small joint effusion, and serum inflammatory markers were elevated. Arthrocentesis yielded 12ccs of culture-negative cloudy serous fluid containing 3,270 white blood cells, 92% polymorphonuclear neutrophils. The patient underwent prosthesis explant, antibiotic spacer placement, and began empiric IV antibiotic therapy as stage one of a planned two-stage revision. Intraoperative tissue cultures were negative, and the postoperative plan was to continue IV vancomycin for a total of 6 weeks. Two weeks post-op, serum Lyme antibody testing returned positive. The patient was switched to doxycycline and ceftriaxone for a total duration of 4 weeks, followed by a successful second-stage revision and remains asymptomatic after 1 year. Five cases of culture-negative prosthetic joint infections caused by the spirochete, Borrelia burgdorferi, have been reported in the orthopaedic literature.1-4 We present a sixth case, occurring in a 68-year-old woman in Northwestern Pennsylvania, 8 years after a primary right total knee arthroplasty.