[Airborne contamination and post-operative infection (author's transl)].

The authors have studied the rate of infection after 14000 orthopaedic interventions performed in the same hospital during the period between 1971 and 1978. 1020 of these were performed in a vertical air flow enclosure with a clearance of air at a rate of 425 times per hour. The others were performed in the conventional operating theatre with an air clearance of 22 times per hour. The density of particles was found to be 50 to 100 times lower at the level of the incision in cases operated on under vertical flow. Depsite this, the rate of infection was 0.7p. 100 in the conventional theatre and 1.4p. 100 in the vertical flow theatre. However, if the study was limited to hip prostheses (1382 cases), the rate of infection was about the same: 2,9p. 100 in conventional theatres and 3,2p. 100 in vertical flow enclosures. It is concluded that the role of a vertical air flow enclosure in decreasing the rate of post-operative infection in doubtful. The authors recall the effects of previous operations on liability to infection and consider that the use of cement may increase the incidence of infection. They advocate the use of cementless, self-locking total prostheses.