In our report we present the case of a 74-year-old man in whom Pseudomonas aeruginosa was identified unexpectedly in intra-operative samples taken during a one-stage revision total hip arthroplasty (THA). The patient was treated with a post-operative, eight-week antibiotic course and, subsequently, was free of infectious symptoms. However, 6 years later an infection of his THA was detected and Pseudomonas aeruginosa was again isolated. In accordance with traditional thinking this should be classified as a new infection, but some recent findings on the relationship between the host and infecting bacteria allow us to interpret this case as a recurrent infection of THA. It is speculated whether at all, or for how long, it is possible for bacteria to survive on the prosthetic surfaces without either eliciting the host's immune response or severely damaging the surrounding tissues. If it is so, prosthetic joint infection can be understood as a disturbed equilibrium between bacteria colonising the implant and the host's immune mechanisms, and thus this concept could lead to the development of new methods for prevention of this feared THA complication.

Ortopedická klinika LF UP a FN Olomouc Olomouc