Apparatus of the present invention include encapsulating the antibiotic in fine particles of bioabsorbable polymer which will yield a constant dissolution of the antibiotic over a predefined dosing period (such as a 7-10 day period), with residual antibiotic being thereafter delivered only until the bioabsorable polymer is resorbed; and delivering the fine particle powder to the surgical site as an aerosol spray. It is preferable that the antibiotic and the polymer be thermostable so that the exothermic reaction of bone cement does not degrade the polymer or the antibiotic. A suitable antibiotic for this purpose is an aminoglycoside. One apparatus according to the invention includes a porous delivery tube which is dimensioned to fit comfortable in a bone canal and which is coupled to a aerosol canister containing the antibiotic powder of the invention. Another apparatus according to the invention includes a porous delivery tube which is preloaded with measured amounts of antibiotic powder and which is adapted to be coupled to a source of compressed air.