This is a report on the present situation in a continuing study of postoperative wound infection, with special reference to the cleanliness of air in operating rooms. In 85 (1.6%) infections in 5,800 total hip replacements between 1960 and the end of 1970, the incidence rate fell from the region of 7 per cent to 0.5 per cent purely as a result of measures taken to prevent exogenous infection in the operating room. No precautions were taken to isolate against cross-infection in the wards between patients newly admitted and old, or even infected, patients already in hospital. Prophylactic antibiotics were purposely avoided to make this a study of asepsis. The fall in infection rate is regarded as proving that acrylic cement, which was used throughout the 10 years of this study, is not responsible for postoperative infections. In the same way, the fall in infection rate indicates that blood-borne infection also is unlikely to be responsible for more than 0.5 per cent of infections. It is believed that of all the precautions taken against infection in the operating room, the most important was clean air; but it is emphasized that this measure alone did not reduce the infection rate below about 1.5 per cent. The further reduction below 1.5 per cent in 1969/1970 is believed to be due to measures taken to avoid penetration of bacteria through the textile of the surgeon's operating gown, and also to improved methods of wound closure. It is emphasized that statistical criteria invalidate most of the published figures for wound infection, and will set limits to the validity of comparisons at the 0.5 per cent level of infection; in this type of implant surgery, the infection rate cannot be established until 2 or 3 years have elapsed from the time of the operation.
Copyright remains with the authors and publisher.
This is a report on the present situation in a continuing study of postoperative wound infection, with special reference to the cleanliness of air in operating rooms. In 85 (1.6%) infections in 5,800 total hip replacements between 1960 and the end of 1970, the incidence rate fell from the region of 7 per cent to 0.5 per cent purely as a result of measures taken to prevent exogenous infection in the operating room. No precautions were taken to isolate against cross-infection in the wards between patients newly admitted and old, or even infected, patients already in hospital. Prophylactic antibiotics were purposely avoided to make this a study of asepsis. The fall in infection rate is regarded as proving that acrylic cement, which was used throughout the 10 years of this study, is not responsible for postoperative infections. In the same way, the fall in infection rate indicates that blood-borne infection also is unlikely to be responsible for more than 0.5 per cent of infections. It is believed that of all the precautions taken against infection in the operating room, the most important was clean air; but it is emphasized that this measure alone did not reduce the infection rate below about 1.5 per cent. The further reduction below 1.5 per cent in 1969/1970 is believed to be due to measures taken to avoid penetration of bacteria through the textile of the surgeon's operating gown, and also to improved methods of wound closure. It is emphasized that statistical criteria invalidate most of the published figures for wound infection, and will set limits to the validity of comparisons at the 0.5 per cent level of infection; in this type of implant surgery, the infection rate cannot be established until 2 or 3 years have elapsed from the time of the operation.
Copyright remains with the authors and publisher.