Abstract: Methods are disclosed for preventing or treating infection in a living patient at the site of a void in the patient's body created by surgery. The methods involve the use of biodegradable antibiotic implants which are placed in the surgical void and then supply an extended, continuous supply of at least one antibiotic to the surrounding tissue. The biodegradable implant comprises at least one biodegradable material such as polylactic acid, and at least one antibiotic drug. These components are combined and formed into bead, rods, or a gel which can be placed in the surgical void. The implant preferably comprises a plurality of antibiotics, each of which is specific to a different bacteria, which bacteria may be expected to be present at the site of the surgicalThe United States Government has certain rights in the present invention pursuant to NIH Grant No. S07RR05427.