From 1. 1. 1971--30. 6. 1977 (6.5 years) 4,169 aseptic orthopaedic operations were performed in the Orthopädische Universitätsklinik Düsseldorf. 42 complications of wound healing have been observed (1%)9 Without an ultrasteril operationbox it is also possible to reduce the complications of wound healing in orthopaedic surgery. It is important to know the principles of asepsis and antisepsis, the method of our preoperative preparation of patients is described; the indication of prophylaxis of chemotherapeutic agents should be severe.