Eradication of bacteria in forefoot surgery in necessary to prevent post-operative infections. Currently a lack of consensus exists on the optimum solution and preparation methods needed to achieve this. We compared the effect of povidine-iodine and chlorhexidine gluconate on lowering bacterial load and if any additional benefits are gained by pre-treatment with the use of a bristled brush.

Fifty consecutive patients undergoing forefoot surgery were recruited into the study and randomised to receive one of two surgical skin preparations (Povidine-iodine 1% with isopropyl alcohol 23% or Chlorhexi-dine gluconate 0.5% with isopropyl alcohol 70%). In addition to the skin preparation of the foot with the randomised solution the other foot was also scrubbed with a sterile surgical bristled brush for a standardised period (3 minutes) and then painted again. Swabs were taken from three sites and analysed via qualitative and quantitative analysis.

All four methods significantly decreased (p < 0.001), in all three sites, the number of colony forming units. Using two-way analysis of variance no significant interaction was observed between site of swab and method of preparation (p =0.970). This confirms that no preparation method was more superior in reducing the number of CFUs at any site than the others.

We suggest that either povidone –iodine with no more that 23% isopropyl alcohol or chlorhexidine gluconate with 70% isopropyl alcohol be used for surgical preparation in forefoot surgery. No additional benefit in reduction in bacterial load is gained by scrubbing the foot prior to painting with bristles.