The penetration of flucloxacillin into cortical and cancellous bone during arthroplasty of the knee.

Antibiotic prophylaxis with 2 g flucloxacillin was given 2 h before operation in 23 adult patients undergoing knee replacement operations for rheumatoid arthritis or osteoarthrosis. The mean extracted concentration of flucloxacillin obtained at operation was 12.9 micrograms/ml (SD 5.25) in synovial fluid; 2.9 micrograms/g (SD 3.59) in synovium; 2.0 micrograms/g (SD 1.48) in cancellous bone and 1.3 micrograms/g (SD 1.25) in cortical bone. The minimum inhibiting concentration (MIC) value for flucloxacillin was usually 0.25 micrograms/g against Staphylococcus aureus. Therapeutically active concentrations were thus obtained. There were no adverse reactions from the antibiotic administration.