Linezolid in the treatment of Gram-positive prosthetic joint infections

Objectives: To investigate the clinical efficacy and safety of linezolid in the treatment of Gram-positive prosthetic hip and knee infections. Materials and methods: A retrospective evaluation of patients hospitalized in the Department of Infectious Diseases of San Martino Hospital in Genoa with the diagnosis of Gram-positive prosthetic joint infection and treated with intravenous and/or oral linezolid. Primary end points were the patient clinical outcome at the end of treatment and at long-term follow-up (up to 12 months after the end of treatment). Results: Between May 1999 and September 2003, 20 patients with prosthetic joint infection were treated with linezolid. Pathogens isolated were: methicillin-resistant Staphylococcus aureus (MRSA), 14 strains; methicillin-resistant coagulase-negative staphylococci, five strains; and Enterococcus spp., one strain. The overall duration of treatment was 7.2 +/- 2 weeks (range 6-10 weeks). Patients were given intravenous therapy for 3-7 days as inpatients, then were changed as outpatients to oral therapy under weekly laboratory testing. At long-term follow-up (1 year), we observed four cases of failure due to relapsing infections. The other 16 patients treated with linezolid did not need further surgical substitution of prosthesis or surgical joint revision. Linezolid was well tolerated, and no drug-related events leading to discontinuation of treatment were recorded. Conclusions: Our data indicate that linezolid may be an effective alternative therapy for orthopaedic infections caused by Gram-positive resistant pathogens and that a prospective and comparative evaluation of linezolid in this setting is necessary.