The effect of 10% povidone--iodine solution on contaminated bone allografts

The aim of this study was to determine the efficacy of 10% povidone--iodine solution for the decontamination of bone allografts. Bone samples were prepared and tested for sterility using a femoral head removed at the time of primary hip replacement. They were contaminated by a suspension of Staphylococcus epidermidis and ground to measure the quantity of micro-organism attached to the bone. Two levels of contamination were used (1 x 10(3) vs. 1 x 10(4)CFU/mL) to check the efficiency of our method of measurement. Samples of the two groups were decontaminated with 10% povidone--iodine solution using different exposure times. Before decontamination, the count of bacteria attached to the bone was proportional to the bacterial concentration of the contaminating solution. The microbiocidal activity of 10% povidone--iodine solution was the same in both groups. The decontamination time was proportional to the bacterial concentration of the contaminating solution. The results of this preliminary study suggest that a 10% povidone--iodine solution can decontaminate inoculated bone grafts, but a sufficient time of exposure according to the level of contamination must be allowed.