Further methodological improvement in antibiotic bone concentration measurements: penetration of ofloxacin into bone and cartilage.

Ten patients (mean age 63 years) undergoing alloarthroplastic hip joint replacement received 400 mg ofloxacin orally before anaesthesia. Venous blood samples were obtained before administration of the drug and then at intervals of up to 24 h. Bone samples were taken from femoral head and femoral shaft. Antibiotic concentrations were assessed by means of HPLC. The maximum serum concentration was 3.45 mg/l on average, after 90 min, and the maximum average bone concentration was 1.22 mg/l after 270 min. The half-life of ofloxacin in bone was shorter than that in serum. The concentrations measured in bone were superior to the minimal inhibitory concentrations reported for most pathogens of bone and joint infections. Therefore ofloxacin appears to be a valuable contribution to the therapeutic options of oral treatment for bone and joint infections.