The role of implant porosity on the development of infection.

The role of implant porosity as a determinant of infection was studied. Standardized porous and nonporous polymethyl methacrylate implants were fabricated for this investigation. In rabbits, the premolded polymethyl methacrylate implants were placed under the paravertebral fascia, just superficial to the paravertebral muscle fascia, before inoculation with a measured number of staphylococci. The polymethyl methacrylate implants did not enhance the infection rate of the contaminated wounds. The presence of pores within the implants did not damage tissue defenses. Polymethyl methacrylate implants did not alter the success of antibiotic treatment. Antibiotics prevented the development of infection in wounds containing 10(6) organisms, even in the presence of an implant. When higher levels of organisms were delivered to the wound, antibiotic treatment had a negligible benefit in the implant and control wounds.