TREATMENT OF OSTEOMYELITIS WITH A BIODEGRADABLE ANTIBIOTIC IMPLANT

A biodegradable antibiotic implant was developed and evaluated in a lo calized osteomyelitic rabbit model. The biodegradable antibiotic impla nt was made of polylactic acid and poly(D1-lactide):co-glycolide combi ned with vancomycin. Localized rabbit tibial osteomyelitis was develop ed with Staphylococcus aureus, Infected rabbits were divided into eigh t groups, depending on treatment with or without debridement, systemic antibiotics, or biodegradable beads, After 4 weeks of therapy, the ra diographs were obtained of the involved bones, which also were culture d for concentrations of Staphylococcus aureus per gram of bone, Treatm ent with antibiotic containing polylactic acid and poly(D1-lactide):co -glycolide beads, with and without systemic vancomycin, resulted in bo ne colony forming unit levels of 10(2.93) and 10(2.84) colony forming units per gram bone, respectively, These bacterial concentrations were approximately 100 times lower than those observed for all other treat ment groups, A biodegradable antibiotic bead may provide extended bact ericidal concentrations of antibiotics for the time needed to complete ly treat the particular orthopaedic infection and does not require the surgery needed to remove the polymethylmethacrylate beads.