TREATMENT OF EXPERIMENTAL OSTEOMYELITIS BY SURGICAL DEBRIDEMENT AND THE IMPLANTATION OF BIOERODABLE, POLYANHYDRIDE-GENTAMICIN BEADS

Osteomyelitis was induced in the radius in 77 rabbits and confirmed by histological examination and culture. At 4 weeks, the wounds were deb rided and the animals were treated with (a) fatty acid dimer-sebacic a cid beads (a bioerodable composite) impregnated with 20% or (b) 10% ge ntamicin sulfate, (c) placebo beads and intramuscular gentamicin sulfa te, (d) placebo beads alone, or (e) debridement only. After 4 weeks, e radication of infection was determined by histological examination and culture. Osteomyelitis was eradicated in 93% of the animals treated w ith the beads and 20% gentamicin, in 67% of those treated with the bea ds and 10% gentamicin, in 25% of those treated with placebo beads and intramuscular gentamicin, in 7% of those treated with placebo beads al one, and in 12.5% of those treated with debridement only (p values fro m <0.001 to 0.02). Fatty acid dimer-sebacic acid beads with gentamicin were then implanted in noninfected rabbits, and gentamicin sulfate co ncentrations in bone, serum, urine, and wound exudate were measured. G entamicin sulfate was detectable in bone for as long as 8 weeks after implantation. Levels as high as 4,746 mu g/ml were present in the woun d exudate for the first 7 days. Levels in the serum peaked at 1.03 mu g/ml. Urine levels peaked at 135 mu g/ml.