Clinical response to antibiotic impregnated polymethyl methacrylate bead implantation of dogs with severe infections after limb sparing and allograft replacement - 18 cases (1994-1996)

Successful treatment of severe orthopaedic infections in people and animals has been augmented by the use of antibiotic impregnated polymethyl methacrylate (PMMA) bead implantation at the site of infection. High local wound concentrations of antimicrobials can be achieved without resulting in toxic levels systemically. Clinical, radiographic and pathological response was evaluated following PMMA beads impregnated with vancomycin and tobramycin implanted in 18 dogs with severe infections following "limb sparing" operation with allograft replacement for osteosarcoma. A variety of aerobic and anaerobic bacterial organisms were cultured from the sites of infection and numerous systemic antimicrobial drug combinations were used in an attempt to control the infections prior to the implantation of the beads. In 12 of 18 (67%) dogs implanted, clinical signs of infection resolved within a median of four weeks post implantation. Three of 12 (25%) had recurrence of signs at a median of 17 weeks post implantation. This was not a randomized, prospective controlled trial and limitations to the study exist, the most notable being the variability in individual patient treatment. However, antibiotic impregnated PMMA bead implantation may play a role in the treatment of severe infections in dogs.