Efficacy of moxifloxacin compared to teicoplanin in the treatment of implant‐related chronic osteomyelitis in rats

Treatment of implant‐related chronic osteomyelitis is often difficult and usually consists of implant removal, extensive surgical debridement, and prolonged antibiotic use. This study was performed to assess the efficacy of moxifloxacin compared to a glycopeptide, teicoplanin in chronic implant‐related methicillin‐sensitive Staphylococcus aureus (MSSA) osteomyelitis. The left femoral medullar cavities of 60 Wistar male rats were contaminated with 100 µl of 10⁸ cfu/ml methicillin‐sensitive S. aureus (ATCC 29213) and Kirschner wires were placed into the medulla of the femur. After 6 weeks, rats were randomly divided into five groups. In two groups, the Kirschner wires were removed. Experimental groups were as follows: group 1: contaminated, Kirschner wire inside, received teicoplanin; group 2: contaminated, Kirschner wire removed, received teicoplanin; group 3: contaminated, Kirschner wire inside, received moxifloxacin; group 4: contaminated, Kirschner wire removed, received moxifloxacin; group 5: contaminated, Kirschner wire inside, no antibiotics (control group). Groups 1 and 2 received teicoplanin (20 mg/kg once daily), whereas groups 3 and 4 received moxifloxacin (10 mg/kg twice daily) intraperitoneally for 28 days. At the end of the treatment, animals were sacrificed by inhalation anesthesia with ether and femora were retrieved and bacterial counts (cfu/g) were determined. Bacterial counts in all study groups were significantly reduced relative to the control. The decrease of bacterial counts was more prominent in group 4 compared to group 1 (p = 0.001) and group 2 (p = 0.003). Moxifloxacin therapy is an effective alternative to teicoplanin for chronic implant‐related MSSA osteomyelitis. Published by Wiley Periodicals, Inc. J Orthop Res 28:1368–1372, 2010