Examination of a novel, specified local antibiotic therapy through polymethylmethacrylate capsules in a rabbit osteomyelitis model

Chronic bone and soft tissue suppurations have become more frequent recently due to the increasing number of high-energy injuries. There are certain antibiotic beads available for local administration, but they cannot always be applied specifically against the pyogenic microorganisms. In the present study, a new technique of local antibiotic therapy for the treatment of infections is described. Polymethylmethacrylate (PMMA) capsules were produced and filled with 0.1 ml Tazocin (0.02 g piperacillin sodium + 0.005 g tazobactam). The efficacy of these Tazocin-filled capsules was examined in vivo using a rabbit osteomyelitis model. Chronic osteomyelitis was induced in rabbit tibia by local injection of Staphylococcus aureus. The treatment included surgical debridement and implantation of Tazocin-containing PMMA capsules into the medullar cavity (n = 12). Simple surgical debridement with no antibiotic implantation was performed in control animals (n = 7). Results were evaluated using microbiological, radiological and histological methods 14 weeks after induction of osteomyelitis. Eight weeks after the implantation of PMMA capsules, complete physical, radiological and histological healing was achieved in 7 animals, initiation of the reparative phase was observed histologically in 3 cases and no reparative signs were detected in 2 rabbits. In the control group, no significant sign of reparation could be seen in any of the cases.