Through some trials, a relation between the presence of Staphylococci in nasal cavities and an increase in post-operative local infections, representing a severe risk above all in orthopedic interventions with the insertion of prosthesis and orthesis, has been hypothesized. In order to avoid this risk, some orthopedic surgeons perform a sterilization of nasal cavities before intervention. A recent trial, however, puts under discussion the usefulness of this procedure. In France, a prospective trial has been performed in 17 orthopedic centers on 3908 patients undergoing surgeries during the period 2003-2007: nasal samples and cultures have been taken from all patients at hospitalization, with a finding of Staphylococcus aureus in 790 subjects (20%). In the overall, 77 patients (2%) have developed infections in the surgery seat, and the Staphylococcus has been the responsible for 22 of these infections (less than 1% of patients). With multivariate analyses, it was seen that the presence of nasal Staphylococcus-related post-operative infections can be prevalently associated with nasal colonization and use of tobacco, even if it is necessary to specify that 13 of the 22 subjects with staphylococcus-related post-operative infection had not a positive nasal smear at hospitalization. In the 9 patients presenting both nasal colonization and post-operative infection, a comparison between nasal bacterial strains and the ones found in the surgery seat has been performed, not being able however to identify always the same bacteria in the two infection seats: in the overall, referring to all the 22 patients with Staphylococcus-related post-operative infection, only in 6 of them they have been able to find that the origin of the infection was nasal.
For Staphylococcus-related post-operative infections, only a little part of them is due to nasal colonization preceding surgery and this explains the reason why nasal sterilization procedures have not obtained, up to now, the desired effects on the incidence of surgical infections. It is necessary to proceed following other ways, keeping in mind that an interesting relation between smoke and Staphylococcus-related infection has been shown.
