Osseous concentrations of gentamicin after implantation of acrylic bone cement in sheep femora.

17 sheep received femoral implantation of 'Cérafix Genta', containing gentamicin 0.6 or 1.2 g per dose either unilaterally (first 3 sheep) or bilaterally (remaining 14 sheep). Highest concentrations in bone were measured after 24 and 48 post-operative hours (respectively 36 and 72 mg/kg for Cérafix 0.6 g and 1.2 g). Gentamicin concentrations in bone marrow and femoral heads were in the same range. Blood and urine concentrations of gentamicin measured in sheep were comparable to those obtained in man. An extrapolation of the gentamicin behaviour from sheep to humans, might be possible: the sheep weight and femoral dimensions were comparable to those of humans and the method of implantation was similar in man and animal. For up to 18 months after operation, gentamicin levels in bone were always higher than critical concentration (4 mg/kg). For the early post-operative period, blood and urine levels always remained below gentamicin toxic concentrations.