title: Treatment of experimental osteomyelitis by methicillin resistant Staphylococcus aureus with bone cement system releasing grepafloxacin.
abstract: The authors examined the effectiveness of the local anti-microbial treatment on methicillin resistant Staphylococcus aureus (MRSA) experimental osteomyelitis. Thirty-six rabbits with chronic MRSA osteomyelitis of the right femur were treated with local grepafloxacin delivery system prepared by a mixture of acrylic bone cement (polymethyl methacrylate, PMMA) plus 4% grepafloxacin. Osteomyelitis was induced by inoculating MRSA (100 microl of cultured bacteria; 10(7)) and the local insertion of a needle, serving as a foreign body, at the upper third of the femur. The course of the infection was followed by clinical, radiographic and microbiological examination. In the third week, all animals were re-operated, needles were removed, and antibiotic containing acrylic cement was implanted. Thereafter, one control and five treated animals were sacrificed per week, within 6 weeks. Osteomyelitis was found in all rabbits. In vitro grepafloxacin levels remained high throughout the 6 weeks of the experiment. Histologically tissue reaction against the cement was not observed. Osteomyelitis lesions and bone structure were progressively repaired after cement implantation. Biomechanical analysis showed no significant influence on the mechanical properties of acrylic cement due to grepafloxacin. The above mixture could prove to be an important supplementary method for the treatment of bone infections. Such a system could replace the use of gentamycin PMMA beads in the treatment of patients with chronic osteomyelitis due to MRSA. Furthermore, the proposed method could be used as a spacer after removal septic loosened prostheses in combination with systemic administration of antibiotics.
authors.affiliation: Athens University, 2nd Orthopaedic Department, Athens, Greece.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Efstathopoulos
authors.forename: Evangellos
authors.initials: E
authors.lastname: Giamarellos-Bourboulis
authors.forename: Kyriaki
authors.initials: K
authors.lastname: Kanellakopoulou
authors.forename: Ioannis
authors.initials: I
authors.lastname: Lazarettos
authors.forename: Peter
authors.initials: P
authors.lastname: Giannoudis
authors.forename: Konstantina
authors.initials: K
authors.lastname: Frangia
authors.forename: Evangellos
authors.initials: E
authors.lastname: Magnissalis
authors.forename: Maria
authors.initials: M
authors.lastname: Papadaki
authors.forename: Vassilios S
authors.initials: VS
authors.lastname: Nikolaou
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001843:Bone Cements / Q000627:therapeutic use; D024841:Fluoroquinolones / Q000627:therapeutic use*; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects*; D010019:Osteomyelitis / Q000188:drug therapy* / Q000382:microbiology / Q000473:pathology; D010879:Piperazines / Q000627:therapeutic use*; D016459:Prosthesis-Related Infections / Q000188:drug therapy*; D011817:Rabbits; D013203:Staphylococcal Infections / Q000188:drug therapy* / Q000382:microbiology / Q000473:pathology
chemical_list: D000900:Anti-Bacterial Agents; D001843:Bone Cements; D024841:Fluoroquinolones; D010879:Piperazines; C075375:grepafloxacin