Antibiotic treatment can be safely stopped in asymptomatic patients with prosthetic joint infections despite persistent elevated C-reactive protein values.

OBJECTIVE: Prosthetic joint infection should be treated for a prolonged time (3 months for hip, 6 months for knee infection). Most authors require normalization of CRP before stopping antimicrobial therapy. However, in some patients the CRP values remain slightly elevated despite adequate treatment.
METHOD: We observed 14 patients with prosthetic joint infection (6 knee, 9 hip infections), in whom the CRP values never fell below the upper limit of normal. Eleven patients were surgically treated with débridement and retention of the prosthesis, in one patient one-staged reimplantation and in two patients two-staged reimplantations were performed. Antibiotic treatment was stopped according the guidelines, if the patient was clinically without signs of persistent infection and the CRP values reached a plateau, albeit above the cut-off (5 mg/L). All patients were followed for 2 years after primary diagnosis of infection.
RESULTS: Only one patient developed a periprosthetic infection five months after stopping antibiotic therapy. However, the isolated pathogen was different from that of the patient's first infection, so we postulate a reinfection rather than a relapse. All other patients remained free of infection for the observed period.
CONCLUSION: Antibiotic treatment can safely be stopped in patients with prosthetic joint infection, even if CRP is not normalized, given that there are no clinical signs of persistent infection and a plateau of CRP level is obtained.