Effects of using a Charnley-Howorth enclosure in a district general hospital

A high rate of infection was found to occur when total hip replacement were performed in an operating theatre used by a variety of surgical specialities. Because of this, a downward displacement laminar flow enclosure was installed to provide ultraclean air operating conditions. Retrospective examination of 419 total hip replacements, carried out over a six-year period during which the enclosure was installed, showed a reduction in the infection rate from 3.2% to 0.4% (P = 0.05) when using the enclosure. The infections were associated with a postoperative wound discharge and with revision surgery but were less frequent when the enclosure was used. Prosthetic loosening was found to be common when metal-to-metal prostheses were used. Working in an enclosure with side panels, wearing body exhaust units, was generally considered to be so noisy as to restrict communication.