Oral treatment of Staphylococcus spp. infected orthopaedic implants with fusidic acid or ofloxacin in combination with rifampicin

Oral therapy of staphylococcal infection of orthopaedic implants with 900 mg/day rifampicin combined with either 1.5 g/day fusidic acid for 5 days followed by 1 g/day thereafter, or 600 mg/day ofloxacin was compared. Patients with an infected hip were treated for 6 months, with removal of any unstable prosthesis after 5 months' treatment and those with an infected knee prosthesis were treated for 9 months, with removal of the prosthesis after 6 months of treatment. Patients with infections of other type of bone implants were treated for 6 months with removal of the implant after 3 months of treatment, if necessary. Cure was defined as the absence of clinical, microbiological and radiological evidence of infection 12 months after completion of treatment. The treatment of 46 of the 52 included in the study was evaluated for safety and that of 42 was assessed for efficacy. Overall treatment was successful for 11 (55%) of 20 patients treated with rifampicin and fusidic acid group and for 11 (50%) of the 22 treated with rifampicin and ofloxacin. Treatment failed in four cases in each treatment group because of persistent infection. One patient given rifampicin and fusidic acid and three patients given rifampicin and ofloxacin failed treatment because of relapse. Superinfection led to failure in the remainder and was due to staphylococci in all but one case in which Acinetobacter calcoaceticus var. anitratus was isolated. There were no side effects related to study treatment. Oral treatment with rifampicin combined with fusidic acid may be a suitable alternative to the combination of rifampicin and ofloxacin for treating implant infections due to Staphylococcus spp. either when the patient is intolerant to quinolones or when the infecting organism is resistant to these drugs.