The effectiveness of standard povidone iodine surgical preparation in decontaminating external fixator components

The purpose of this study was to evaluate the effectiveness of standard iodine surgical scrubs to remove bacteria from external fixator components. Sterile adjustable external fixation clamps, Schanz pins, and carbon fibre rods were coated with a sterile protein solution and immersed in solution of coagulase negative Staphylococcus (103 organisms/ml). They were then decontaminated in standard fashion using a povidone iodine scrub and paint solution. After neutralisation the components were sonicated, serially diluted, plated on blood agar, and incubated for 24 h. Unassembled external fixation components were examined individually, and as assembled pin-rod-clamp constructs with and without manipulation of the clamp. Of the three external fixation components (pins, rods, clamps) the highest number of bacterial colony forming units was seen on the external fixation clamps. Manipulation of the assembled construct significantly increased the mean bacterial colony counts compared to the assembled non-manipulated construct (p = 0.0007). Standard surgical preparation does not remove all bacteria from external fixators during subsequent operative procedures.