Abstract
The purpose of this study was to assess if the use of sterile stockings in lower limb surgery results in the contamination of the operative site with skin commensals from unprepared skin.
Twenty-five consecutive patients under going elective single knee arthroscopy were included in our study. All patients were operated on in the same laminar airflow theatre, by the same surgeon using the same method of skin preparation and operative technique.
Skin swabs were taken from each patient’s foot prior to the commencement of surgery. The limb was then prepared as follows;
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An unscrubbed assistant holds up the leg, the leg is then prepared with betadine, by the surgeon from ankle to thigh, sparing the foot.
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The surgeon then towels off the thigh.
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The surgeon with the stocking in his hand, then takes hold of the foot using the stocking and unrolls it over the foot and up the leg.
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The stocking is bandaged in place and surgery commences.
Two samples were also cut from the cuff of the stocking, one prior to its use to act as a control and the other once it had been unrolled up the leg. The three samples were then sent to microbiology. The swabs were plated out on blood (x2), chocolate and Maconkey agar. One blood plate was incubated anaerobically at 37°c and the others in air at the same temperature. The stocking sample was cultured in nutrient broth. After 48 hours isolates were identified using standard techniques.
The results showed that none of the stocking samples yielded positive microbiology, however all of the foot swab samples did. They all grew coagulase negative Staphylococcus (CNS), five also grew conforms and one grew Pseudomonas, as well.
We can conclude from this, that this method of skin preparation using the sterile stocking is safe. It appears in this study, that the action of unrolling the stocking over the unprepared foot and then up the prepared leg does not contaminate the prepared operative site with commensals from the foot. However concern is raised by the high incidence of CNS on the foot, and may be a source of potential infection.
The abstracts were prepared by Mr Roger Smith. Correspondence should be addressed to him c/o British Orthopaedic Association, Royal College of Surgeons, 35-42 Lindoln’s Inn Fields, London WC2A 3PN.
